JP7547876B2 - Semiconductor device manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a semiconductor device.

Until now, wire bonding methods using thin metal wires such as gold wires have been widely used to connect semiconductor chips and substrates. However, in order to meet the demands for high performance, high integration, and high speed for semiconductor devices, flip chip connection methods (FC connection methods) are becoming more widespread, in which conductive protrusions called bumps are formed on the semiconductor chip or substrate to directly connect the semiconductor chip and substrate.

Known FC connection methods include metal bonding using solder, tin, gold, silver, copper, etc., metal bonding by applying ultrasonic vibrations, and maintaining mechanical contact using the contraction force of resin. From the standpoint of reliability of the connection, however, metal bonding using solder, tin, gold, silver, copper, etc. is more commonly used.

For example, when connecting a semiconductor chip to a substrate, the COB (Chip On Board) type connection method that is widely used for BGA (Ball Grid Array) and CSP (Chip Size Package) is also an FC connection method.

The FC connection method is also widely used in COC (Chip On Chip) type connection methods, in which bumps or wiring are formed on semiconductor chips to connect between semiconductor chips.

JP 2008-294382 A

For packages that are required to be even smaller, thinner, and more functional, chip-stack packages that use the above-mentioned connection methods in multiple layers, such as package-on-package (POP) and through-silicon via (TSV), are becoming more widely used.

The above technology is widely used because it allows packages to be made smaller by arranging the wiring in a three-dimensional rather than flat shape, and is also effective in improving semiconductor performance, reducing noise, reducing mounting area, and saving power, and is attracting attention as a next-generation semiconductor wiring technology.

From the perspective of improving productivity, COW (chip on wafer), in which semiconductor chips are bonded (connected) onto a wafer and then diced to create a semiconductor package, and WOW (wafer on wafer), in which wafers are bonded (connected) together and then diced to create a semiconductor package, are also attracting attention.

In assembling the above-mentioned flip chip package, first, a semiconductor chip is picked up from a diced wafer with a collet, or a semiconductor chip to which a semiconductor adhesive has been applied, and then supplied to a crimping tool via the collet.

Next, the chip is aligned with the chip or with the substrate, and then they are pressed together.

The temperature of the crimping tool is raised so that the metal at the top and bottom connections, or at least one of the top and bottom connections, reaches or exceeds its melting point so that a metallic bond is formed.

In a multi-layered, stacked chip package, chip pickup, alignment, and compression are repeated.

Then, to protect the semiconductor package, the top surface of the chip is sealed with sealing resin to form an encapsulant.

In the assembly of conventional flip chip packages, differences in the thermal expansion coefficients between the chip and the semiconductor encapsulant, or between the chip and the substrate, can cause the semiconductor package to warp after compression bonding. This warping can lead to problems such as an inability to perform overmolding and poor connection of the package.

One method for manufacturing a semiconductor device that can suppress warping when semiconductor components are connected to each other is to seal the semiconductor chip with resin before carrying out the process of forming metallic bonds by heat treatment at a temperature higher than the melting point of the metal in the connection parts, etc. However, it has been found that semiconductor packages produced using this method are prone to defects such as peeling between the semiconductor components and the sealing material when exposed to temperatures expected in the process of forming metallic bonds after absorbing moisture.

In general, a sealed semiconductor package is ultimately mounted on a substrate such as a motherboard. At that time, it is necessary to connect other components to the package by forming metallic bonds or the like. In other words, even after the process of forming metallic bonds at the connection parts of the package and the sealing process are completed, the package is exposed to high temperatures that cause metal formation. In addition, not only when wet processing is required for components other than the package that are mounted on other substrates, but also when moisture in the air causes the package to absorb moisture. For this reason, general semiconductor packages are required to have heat resistance that can suppress peeling between components at reflow temperatures even in a moist state after the process of forming the connection parts and the sealing process are completed.

The present invention has been made in consideration of the above circumstances, and aims to provide a method for manufacturing a semiconductor device that can obtain a semiconductor device that has heat resistance that can withstand the temperatures expected in the process of forming metal bonds (and can suppress peeling between each component) even in a hygroscopic state in which peeling due to warping is more likely to occur.

In order to achieve the above object, the present invention provides the following inventions.
[1] A method for manufacturing a semiconductor device comprising a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other, or a semiconductor device comprising a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other, comprising:
The connection portion is made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection portion so that the connection portions are in contact with each other, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of heating the temporary sealed connection body at a temperature equal to or higher than the melting point of the metal of the connection portion to obtain a sealed connection body;
(d) a fourth step of grinding at least a portion of the sealing resin in the sealed connection body;
A manufacturing method of a semiconductor device comprising:

[2] A method for manufacturing a semiconductor device comprising a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other, or a semiconductor device comprising a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other, comprising:
The connection portion is made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection portion so that the connection portions are in contact with each other, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of grinding at least a portion of the sealing resin in the sealed temporary connection body;
(d) a fourth step of heating the temporary sealed connection body at a temperature equal to or higher than the melting point of the metal of the connection portion to obtain a sealed connection body;
A manufacturing method of a semiconductor device comprising:

[3] A method for manufacturing a semiconductor device comprising a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other via connection bumps, or a semiconductor device comprising a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other via connection bumps,
the connection portion and the connection bump are made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection bumps so that the connection portions of each are in contact with the connection bumps, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of heating the temporary sealing connection body at a temperature equal to or higher than the melting point of the metal of the connection bumps to obtain a sealing connection body;
(d) a fourth step of grinding at least a portion of the sealing resin in the sealed connection body;
A manufacturing method of a semiconductor device comprising:

[4] A method for manufacturing a semiconductor device comprising a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other via connection bumps, or a semiconductor device comprising a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other via connection bumps, comprising:
the connection portion and the connection bump are made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection bumps so that the connection portions of each are in contact with the connection bumps, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of grinding at least a portion of the sealing resin in the sealed temporary connection body;
(d) a fourth step of heating the temporary sealed connection body at a temperature equal to or higher than the melting point of the metal of the connection bumps to obtain a sealed connection body;
A manufacturing method of a semiconductor device comprising:

[5] The method for manufacturing a semiconductor device according to any one of [1] to [4] above, wherein in the step of grinding at least a portion of the sealing resin, grinding is performed until the surface of the semiconductor chip opposite the surface having the connection portion is exposed.

[6] The method for manufacturing a semiconductor device according to any one of [1] to [5] above, in the first step, the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, are sandwiched between a pair of opposing pressing members and heated and pressurized to bond them together.

[7] The method for manufacturing a semiconductor device according to any one of [1] to [6] above, wherein the adhesive for semiconductors contains a compound having a weight average molecular weight of 10,000 or less and a curing agent, and has a melt viscosity of 6,000 Pa·s or less at 80 to 130°C.

［式中、Ｒ^１はアルキル基又はフェニル基を示し、Ｒ^２はアルキレン基を示す。］
［９］上記Ｒ^１がフェニル基である、上記［８］に記載の半導体装置の製造方法。
［１０］上記シラノール化合物が２５℃で固形である、上記［８］又は［９］に記載の半導体装置の製造方法。 [8] The method for manufacturing a semiconductor device described in any one of [1] to [7] above, wherein the adhesive for semiconductors contains a compound with a weight average molecular weight of 10,000 or less, a curing agent, and a silanol compound represented by the following general formula (1):

[In the formula, R ¹ represents an alkyl group or a phenyl group, and R ² represents an alkylene group.]
[9] The method for producing a semiconductor device according to the above [8], wherein R ¹ is a phenyl group.
[10] The method for producing a semiconductor device according to the above [8] or [9], wherein the silanol compound is solid at 25° C.

[11] The method for manufacturing a semiconductor device described in any one of [1] to [10] above, wherein the adhesive for semiconductors contains a high molecular weight component having a weight average molecular weight of more than 10,000.
[12] The method for manufacturing a semiconductor device according to [11] above, wherein the high molecular weight component is a component having a weight average molecular weight of 30,000 or more and a glass transition temperature of 100° C. or less.

[13] The method for manufacturing a semiconductor device according to any one of [1] to [12] above, wherein the semiconductor adhesive is in the form of a film.

The present invention provides a method for manufacturing a semiconductor device that can obtain a semiconductor device that has heat resistance that can withstand the temperatures expected in the process of forming metal bonds (and can suppress peeling between each component) even in a hygroscopic state in which peeling due to warping is more likely to occur.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor device; 1 is a schematic cross-sectional view showing an embodiment of a semiconductor device; 1 is a schematic cross-sectional view showing an embodiment of a semiconductor device; 1 is a schematic cross-sectional view showing an embodiment of a semiconductor device; 1 is a schematic cross-sectional view showing an embodiment of a semiconductor device; 10A to 10C are process diagrams showing an example of a process for temporarily bonding a substrate to a semiconductor chip.

Below, a preferred embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are given the same reference numerals, and duplicate explanations will be omitted. Furthermore, unless otherwise specified, the positional relationships such as up, down, left, right, etc. will be based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of the drawings are not limited to the ratios shown in the drawings.

<Semiconductor Device>
A semiconductor device obtained by the method for manufacturing a semiconductor device according to the present embodiment will be described below with reference to Fig. 1 and Fig. 2. Fig. 1 shows a cross-sectional structure in the case where a connection is made between a semiconductor chip and a substrate, and Fig. 2 shows a cross-sectional structure in the case where a connection is made between semiconductor chips.

Figure 1 is a schematic cross-sectional view showing one embodiment of a semiconductor device. The semiconductor device 100 shown in Figure 1 (a) has a semiconductor chip 10 and a substrate (circuit wiring substrate) 20 facing each other, wiring 15 arranged on the facing surfaces of the semiconductor chip 10 and the substrate 20, connection bumps 30 connecting the wiring 15 of the semiconductor chip 10 and the substrate 20 to each other, an adhesive layer 40 filled without gaps in the gap between the semiconductor chip 10 and the substrate 20, and a sealing resin 60 sealing the connection part of the semiconductor chip 10 and the substrate 20. The semiconductor chip 10 and the substrate 20 are flip-chip connected by the wiring 15 and the connection bumps 30. The wiring 15 and the connection bumps 30 are sealed by the adhesive layer 40 and are isolated from the external environment. The adhesive layer 40 is sealed by the sealing resin 60 and is isolated from the external environment.

The semiconductor device 200 shown in FIG. 1(b) has a semiconductor chip 10 and a substrate 20 facing each other, bumps 32 arranged on the facing surfaces of the semiconductor chip 10 and the substrate 20, and an adhesive layer 40 that fills the gap between the semiconductor chip 10 and the substrate 20 without any gaps. The semiconductor chip 10 and the substrate 20 are flip-chip connected by connecting the facing bumps 32 to each other. The bumps 32 are sealed by the adhesive layer 40 and are isolated from the external environment. Similarly, the adhesive layer 40 is sealed by a sealing resin 60 and is isolated from the external environment. The adhesive layer 40 is a hardened product of a semiconductor adhesive.

Figure 2 is a schematic cross-sectional view showing another embodiment of a semiconductor device. The semiconductor device 300 shown in Figure 2(a) is similar to the semiconductor device 100, except that two semiconductor chips 10 are flip-chip connected by wiring 15 and connection bumps 30. The semiconductor device 400 shown in Figure 2(b) is similar to the semiconductor device 200, except that two semiconductor chips 10 are flip-chip connected by bumps 32. A more specific embodiment of Figure 2(a) is one in which the upper semiconductor chip 10 in the figure has copper pillars and solder (solder bumps) as connection parts, and the lower semiconductor chip 10 in the figure has pads (gold-plated connection parts) as connection parts.

The materials of the conductive protrusions called bumps (connection bumps) mainly include gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper, etc.), tin, nickel, etc., and may be composed of only a single component or multiple components. Also, these metals may be formed to form a laminated structure. The bumps may be formed on a semiconductor chip or a substrate. The metal of the connection part may include relatively inexpensive copper or solder. From the viewpoint of improving connection reliability and suppressing warping, the metal of the connection part may include solder.

The metal surface of the connection part, called a pad, is mainly composed of gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper, etc.), tin, nickel, etc., and may be composed of only a single component or multiple components. Also, it may be formed to have a laminated structure of these metals. From the viewpoint of connection reliability, the pad may contain gold or solder.

A metal layer consisting mainly of gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper, etc.), tin, nickel, etc. may be formed on the surface of the wiring (wiring pattern), and this metal layer may be composed of only a single component or multiple components. It may also have a structure in which multiple metal layers are laminated. The metal of the connection part may contain relatively inexpensive copper or solder. From the viewpoint of improving connection reliability and suppressing warping, the metal of the connection part may contain solder.

The semiconductor device is connected, for example, between the bumps, between the bumps and the pads, or between the bumps and the wiring as described above. In this case, it is sufficient that the metal of one of the connection parts is heated to or above its melting point during the heating process described below (the third step in the first embodiment, or the fourth step in the second embodiment).

The semiconductor chip 10 is not particularly limited, and various semiconductors can be used, including elemental semiconductors such as silicon and germanium, and compound semiconductors such as gallium arsenide and indium phosphide.

There are no particular limitations on the substrate 20 (semiconductor substrate) as long as it is a normal circuit substrate. Examples of the substrate 20 that can be used include a circuit substrate having wiring 15 (wiring pattern) formed by etching away unnecessary portions of a metal film on an insulating substrate surface whose main components are glass epoxy, polyimide, polyester, ceramic, epoxy resin, bismaleimide triazine, etc., a circuit substrate in which wiring 15 is formed on the insulating substrate surface by metal plating, etc., and a circuit substrate in which wiring 15 is formed by printing a conductive material on the insulating substrate surface.

A plurality of structures (packages) such as those shown in the semiconductor devices 100, 200, 300, and 400 may be stacked. In this case, the semiconductor devices 100, 200, 300, and 400 may be electrically connected to each other by bumps or wiring containing gold, silver, copper, solder (main components of which are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, and tin-silver-copper), tin, nickel, etc.

As a method for stacking multiple semiconductor devices, for example, TSV (Through-Silicon Via) technology can be mentioned as shown in FIG. 3. In the TSV technology, a semiconductor adhesive is interposed between semiconductor chips for flip-chip connection or stacking. FIG. 3 is a schematic cross-sectional view showing another embodiment of a semiconductor device, which is a semiconductor device using the TSV technology. In the semiconductor device 500 shown in FIG. 3, the wiring 15 formed on the interposer 50 is connected to the wiring 15 of the semiconductor chip 10 via the connection bump 30, so that the semiconductor chip 10 and the interposer 50 are flip-chip connected. The adhesive layer 40 is filled without gaps in the gap between the semiconductor chip 10 and the interposer 50. On the surface of the semiconductor chip 10 opposite the interposer 50, the semiconductor chip 10 is repeatedly stacked via the wiring 15, the connection bump 30, and the adhesive layer 40. The wiring 15 on the pattern surfaces on the front and back of the semiconductor chip 10 (excluding the outermost layer) is connected to each other by through electrodes 34 filled in holes that penetrate the inside of the semiconductor chip 10. The through electrodes 34 can be made of copper, aluminum, or the like. In a stack consisting of multiple semiconductor chips 10, the adhesive layer 40 is sealed with sealing resin 60 and is isolated from the external environment.

This type of TSV technology makes it possible to obtain signals from the back side of the semiconductor chip, which is not normally used. Furthermore, because the through electrodes 34 are passed vertically through the semiconductor chip 10, the distance between opposing semiconductor chips 10 and between the semiconductor chip 10 and the interposer 50 can be shortened, allowing for flexible connections. The manufacturing method for the semiconductor device of this embodiment can also be applied to the connection between stacked chips and interposers using this type of TSV technology.

Figures 4 and 5 are schematic cross-sectional views showing other embodiments of a semiconductor device. The semiconductor device 600 shown in Figure 4 is similar to the semiconductor device 100, except that multiple semiconductor chips 10 are flip-chip connected to the substrate 20 by wiring 15 and connection bumps 30. The semiconductor device 700 shown in Figure 5 is similar to the semiconductor device 100, except that multiple semiconductor chips 10 are flip-chip connected to the interposer 50 by wiring 15 and connection bumps 30.

<Method of Manufacturing Semiconductor Device>
A method for manufacturing a semiconductor device according to a first embodiment is a method for manufacturing a semiconductor device including a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other via connection bumps, or a method for manufacturing a semiconductor device including a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other via connection bumps, the connection portions and the connection bumps being made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection bumps so that the connection portions of each are in contact with the connection bumps, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of heating the temporary sealing connection body at a temperature equal to or higher than the melting point of the metal of the connection bumps to obtain a sealing connection body;
(d) a fourth step of grinding at least a portion of the sealing resin in the sealed connection body;
Equipped with.

A method for manufacturing a semiconductor device according to a second embodiment is a method for manufacturing a semiconductor device including a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other via connection bumps, or a method for manufacturing a semiconductor device including a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other via connection bumps, the connection portions and the connection bumps being made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection bumps so that the connection portions of each are in contact with the connection bumps, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of grinding at least a portion of the sealing resin in the sealed temporary connection body;
(d) a fourth step of heating the temporary sealed connection body at a temperature equal to or higher than the melting point of the metal of the connection bumps to obtain a sealed connection body;
Equipped with.

By using the manufacturing method of the semiconductor device according to the first and second embodiments described above, it is possible to obtain a semiconductor device as shown in FIG. 1(a) or FIG. 2(a), for example. Each step will be described below using FIG. 2(a) as an example.

First, a film-like semiconductor adhesive (hereinafter sometimes referred to as "film-like adhesive") is applied onto the semiconductor chip 10. The film-like adhesive can be applied by hot pressing, roll lamination, vacuum lamination, or the like. The supply area and thickness of the film-like adhesive are appropriately set depending on the size of the semiconductor chip 10 and the substrate 20, the height of the connection bumps 30, and the like. The film-like adhesive may be applied to the semiconductor chip 10, or the semiconductor chip 10 with the film-like adhesive applied thereto may be produced by applying the film-like adhesive to a semiconductor wafer, followed by dicing to separate the semiconductor chips 10.

The wiring 15 of the semiconductor chip 10 is aligned using a connection device such as a flip chip bonder, and then temporary pressure bonding is performed at a temperature below the melting point of the connection bumps 30 (solder bumps) to obtain a temporary connection body (first step).

Next, the top surface of one of the semiconductor chips 10 in the temporary connection body is sealed to obtain a sealed temporary connection body (second step). The semiconductor chip 10 can be sealed using a compression molding machine, a transfer molding machine, or the like.

In the first embodiment, the sealed temporary connection body is then heated to a temperature equal to or higher than the melting point of the connection bumps 30, and a metal bond is formed between the wiring 15 and the connection bumps 30 to obtain a sealed connection body (the third step of the first embodiment). The heating process can be performed using a thermocompression machine, a reflow furnace, a pressurized oven, etc.

Furthermore, in the first embodiment, the sealing resin 60 is ground until the back surface of the semiconductor chip 10 (the surface opposite to the surface having the wiring 15) is exposed, thereby obtaining a semiconductor device (the fourth step of the first embodiment). The grinding process can be performed using a back grinding device or the like. From the viewpoint of suppressing the occurrence of warping and peeling, it is preferable to perform the grinding until the back surface of the semiconductor chip 10 is exposed, but it is not necessary to perform the grinding until the back surface is exposed, and a part of the sealing resin 60 may remain on the back surface. Even if the sealing resin 60 remains on the back surface, the occurrence of warping and peeling can be reduced compared to before grinding by making the thickness of the sealing resin 60 thinner than before grinding.

The third and fourth steps may be performed in any order, and the same semiconductor device can be obtained in either order. Therefore, in the second embodiment, after the second step, the sealing resin 60 in the sealing temporary connection body is ground until the back surface of the semiconductor chip 10 (the surface opposite to the surface having the wiring 15) is exposed, thereby obtaining a ground sealing temporary connection body (third step of the second embodiment). The ground sealing temporary connection body is then heated to a temperature equal to or higher than the melting point of the connection bumps 30, and a metal bond is formed between the wiring 15 and the connection bumps 30, thereby obtaining a semiconductor device (fourth step of the second embodiment).

According to the above-mentioned method for manufacturing a semiconductor device, by grinding the sealing resin 60 in the third step of the first embodiment or the fourth step of the second embodiment, it is possible to reduce warping regardless of whether moisture absorption has occurred. This makes it possible to suppress the occurrence of peeling at the temperature expected in the process of forming the metal bond, even after moisture absorption, when peeling due to warping is more likely to occur.

Here, if the sealing resin 60 absorbs moisture and is exposed to the temperature expected in the process of forming a metal bond, the difference in thermal expansion coefficient between the semiconductor chip 10 and the sealing resin 60 becomes larger, and warping tends to become larger. In contrast, by grinding the sealing resin 60, the difference in thermal expansion coefficient can be eliminated or reduced, and warping can be suppressed. Peeling is likely to occur at the interface between the semiconductor member and the sealing resin 60, and is likely to occur between the semiconductor member on the back side and the sealing resin 60, and between the semiconductor member on the substrate side and the sealing resin 60. In contrast, by suppressing warping for the above reasons, peeling between the semiconductor member on the substrate side and the sealing resin 60 can be suppressed, and peeling can be suppressed by eliminating the interface between the semiconductor member on the back side and the sealing resin 60 or reducing the thickness of the sealing resin 60 on the back side.

In addition, in the manufacturing methods of the first and second embodiments, by manufacturing a semiconductor device through the above-mentioned first to fourth steps, warping of the connector and the semiconductor device can be suppressed in a series of processes. Furthermore, since the above-mentioned warping can be suppressed, grinding of the sealing resin 60 can be performed easily and accurately. Since the above-mentioned warping can be suppressed, grinding of the sealing resin 60 may be performed at either the third step of the first embodiment or the fourth step of the second embodiment.

An example of the first process will be described. Figure 6 is a process diagram showing an example of the process of temporarily bonding a substrate to a semiconductor chip.

6A, the semiconductor chip 10 having the semiconductor chip body 12, wiring 15 and connection bumps 30 is stacked on the substrate body 22 and the substrate 20 having the wiring 15 as a connection portion while disposing the adhesive layer 40 between them to form the laminate 3. The semiconductor chip 10 is formed by dicing the semiconductor wafer, and then picked up and transported to the substrate 20, and aligned so that the connection bumps 30 and the wiring 15 of the substrate 20 are arranged opposite each other. The laminate 3 is formed on the stage 42 of the pressing device 43 having a pair of pressure heads 41 and a stage 42 as temporary pressure pressing members arranged opposite each other. The connection bumps 30 are provided on the wiring 15 provided on the semiconductor chip body 12. The wiring 15 of the substrate 20 is provided at a predetermined position on the substrate body 22. The connection bumps 30 and the wiring 15 each have a surface formed of a metal material.

Next, as shown in FIG. 6B, the laminate 3 is heated and pressurized by being sandwiched between a stage 42 and a bonding head 41, which serve as temporary bonding press members, thereby temporarily bonding the substrate 20 to the semiconductor chip 10. In the case of the embodiment of FIG. 6, the bonding head 41 is disposed on the semiconductor chip 10 side of the laminate 3, and the stage 42 is disposed on the substrate 20 side of the laminate 3.

When at least one of the stage 42 and the bonding head 41 heats and presses the laminate 3 for temporary bonding, it may be heated to a temperature lower than the melting point of the metal material forming the surface of the connection bumps 30 of the semiconductor chip 10 and the melting point of the metal material forming the surface of the wiring 15 as the connection part of the substrate 20.

During the temporary bonding in the first step, the temperature (temperature of the pressing member) when the bonding tool (temporary bonding pressing member) picks up the semiconductor chip 10 (with the film-like adhesive) is preferably low so that the heat of the bonding tool is not transferred to the collet, semiconductor chip 10, etc. On the other hand, the temperature (temperature of the pressing member) during temporary bonding may be heated to a high temperature so as to increase the fluidity of the film-like adhesive and eliminate voids during rolling, but it is preferable that the temperature is lower than the reaction start temperature of the film-like adhesive. In addition, in order to shorten the cooling time, the difference between the temperature when the bonding tool picks up the semiconductor chip 10 and the temperature during temporary bonding may be small. The difference may be 100°C or less, or 60°C or less. The temperature may be constant at the time of picking up and at the time of temporary bonding. If the difference between the two is 100°C or less, the cooling time of the bonding tool is shortened, and productivity tends to be improved. The reaction start temperature refers to the on-set temperature measured using a DSC (PerkinElmer, DSC-Pyrs1) with a sample weight of 10 mg, a heating rate of 10°C/min, and measurement atmosphere of air or nitrogen.

In view of the above, the temperature of the stage 42 and/or the bonding head 41 may be, for example, 30°C or higher and 130°C or lower while picking up the semiconductor chip, and may be, for example, 50°C or higher and 150°C or lower while heating and pressurizing the laminate 3 for temporary bonding.

The connection load in the first step depends on the number of bumps, but is set taking into consideration the absorption of bump height variations and control of bump deformation. During compression, the load may be large in order to eliminate voids and bring the metal of the connection part of the semiconductor chip 10, or the semiconductor chip 10 and substrate 20, into contact with the connection bump. A large load makes it easier to eliminate voids and makes it easier for the metal of the connection part to come into contact with the connection bump. For example, it may be 0.009 N to 0.3 N per pin (bump) of the semiconductor chip 10.

The pressure bonding time for temporary pressure bonding may be set to a short time from the viewpoint of improving productivity. A short pressure bonding time means that the time during which the connection portion is heated to 230°C or higher during connection formation (e.g., the time when soldering is used) is 5 seconds or less. The connection time may be 4 seconds or less, or 3 seconds or less. Furthermore, if each pressure bonding time is shorter than the cooling time, the effect of the manufacturing method of the present invention can be more effectively achieved.

In the second step, the temporary connection body (semiconductor package) after the first step is carried into a mold for forming the temporary sealed connection body, and sealing resin 60 is supplied onto it. The sealing resin 60 is then pushed out and hardened to form the temporary sealed connection body.

The heat treatment in the third step in the first embodiment or the fourth step in the second embodiment requires a temperature equal to or higher than the melting point of the metal of the connection bump 30 in the sealed temporary connection body. For example, if the connection bump 30 is a solder bump, the temperature may be 230°C or higher and 330°C or lower. If the temperature is low, the metal of the connection bump 30 does not melt, and there is a tendency that sufficient metal bonds are not formed.

The connection time in the third or fourth step may be set to a short time from the viewpoint of improving productivity, and may be a time sufficient to melt the connection bump 30 (solder bump), remove the oxide film and surface impurities, and form a metal bond at the connection portion. Note that connection in a short time means that the time during the connection formation time (main pressure bonding time) during which the connection bump 30 is a solder bump and is heated to 230°C or higher is 5 seconds or less. The connection time may be 4 seconds or less, or 3 seconds or less. The shorter the connection time, the easier it is to improve productivity.

The heat treatment is not particularly limited as long as it can be performed at a temperature equal to or higher than the melting point of the metal of the connection bumps 30 of the sealed temporary connection body, and can be performed using a thermocompression machine, a reflow furnace, a pressure oven, or the like. A thermocompression machine can apply heat locally, which is expected to reduce warping. Therefore, from the perspective of reducing warping, a thermocompression machine may be used. On the other hand, from the perspective of improving productivity, a reflow furnace or a pressure oven that can heat treat many packages at once may be used.

In the first step (preliminary bonding), multiple semiconductor chips 10 may be bonded together. In this case, for example, multiple semiconductor chips 10 may be preliminarily bonded one by one in a planar manner on a wafer, interposer, or map substrate (first step), and then the multiple chips may be sealed together (second step).

In addition, in stack bonding, which is often seen in packages with a TSV structure, multiple semiconductor chips 10 are bonded three-dimensionally. In this case, multiple semiconductor chips 10 may also be stacked one by one and bonded together (first step), and then the multiple chips may be sealed (second step).

A method for manufacturing a semiconductor device according to a third embodiment is a method for manufacturing a semiconductor device including a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other, or a method for manufacturing a semiconductor device including a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other, the connection portions being made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection portion so that the connection portions are in contact with each other, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of heating the temporary sealed connection body at a temperature equal to or higher than the melting point of the metal of the connection portion to obtain a sealed connection body;
(d) a fourth step of grinding at least a portion of the sealing resin in the sealed connection body;
Equipped with.

A fourth embodiment of the manufacturing method of a semiconductor device includes a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, and the connection portions are electrically connected to each other, or a semiconductor device includes a plurality of semiconductor chips having connection portions, and the connection portions are electrically connected to each other, the connection portions being made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection portion so that the connection portions are in contact with each other, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of grinding at least a portion of the sealing resin in the sealed temporary connection body;
(d) a fourth step of heating the temporary sealed connection body at a temperature equal to or higher than the melting point of the metal of the connection portion to obtain a sealed connection body;
Equipped with.

By the manufacturing methods of the semiconductor device of the third and fourth embodiments described above, it is possible to obtain a semiconductor device as shown in, for example, FIG. 1(b) or FIG. 2(b). The third embodiment is similar to the first embodiment, except that the connection parts are connected to each other without the connection bumps 30. The fourth embodiment is similar to the second embodiment, except that the connection parts are connected to each other without the connection bumps 30.

<Adhesive for semiconductors>
The adhesive for semiconductors may contain various components as described below, including a compound having a weight-average molecular weight of 10,000 or less and a curing agent.

(Compounds with weight average molecular weight of 10,000 or less)
There is no particular limitation on the compound having a weight average molecular weight of 10,000 or less, but it is one that reacts with the curing agent contained in the composition. A component having a weight average molecular weight as small as 10,000 or less may decompose during heating and cause voids, but it is easy to ensure high heat resistance by reacting with the curing agent. Examples of such compounds include epoxy resins and (meth)acrylic compounds.

(i) Epoxy resin There is no particular restriction on the epoxy resin as long as it has two or more epoxy groups in the molecule. For example, bisphenol A type, bisphenol F type, naphthalene type, phenol novolac type, cresol novolac type, phenol aralkyl type, biphenyl type, triphenylmethane type, dicyclopentadiene type, various polyfunctional epoxy resins, etc. can be used as the epoxy resin. These can be used alone or as a mixture of two or more types. From the viewpoint of heat resistance and handling, it may be selected from bisphenol F type, phenol novolac type, cresol novolac type, biphenyl type, and triphenylmethane type. The amount of epoxy resin to be blended can be, for example, 10 to 50 parts by mass with respect to 100 parts by mass of the total adhesive for semiconductors. When it is 10 parts by mass or more, since the curing component is sufficiently present, it is easy to sufficiently control the flow of the resin even after curing, and when it is 50 parts by mass or less, the cured product does not become too hard, and the warping of the package tends to be more suppressed.

(ii) (Meth)acrylic compound The (meth)acrylic compound is not particularly limited as long as it has one or more (meth)acryloyl groups in the molecule. As the (meth)acrylic compound, for example, bisphenol A type, bisphenol F type, naphthalene type, phenol novolac type, cresol novolac type, phenol aralkyl type, biphenyl type, triphenylmethane type, dicyclopentadiene type, fluorene type, adamantane type, various polyfunctional acrylic compounds, etc. can be used. These can be used alone or as a mixture of two or more. The amount of the (meth)acrylic compound may be 10 to 50 parts by mass, or 15 to 40 parts by mass, relative to 100 parts by mass of the total adhesive for semiconductors. When the amount is 10 parts by mass or more, the curing component is sufficiently present, so that the flow of the resin after curing can be easily controlled sufficiently. When the amount is 50 parts by mass or less, the cured product does not become too hard, and warping of the package can be further suppressed.

The (meth)acrylic compound may be solid at room temperature (25°C). A solid compound is less likely to cause voids than a liquid compound, and the adhesive for semiconductors has low viscosity (tack) before curing (B stage), making it easier to handle.

The number of functional groups of the (meth)acrylic compound may be 3 or less. When the number of functional groups is 3 or less, curing proceeds sufficiently in a short time, and it is easier to suppress a decrease in the curing reaction rate (the curing network may proceed too quickly, leaving unreacted groups), and the properties of the cured product are more likely to be improved.

The weight average molecular weight of a compound having a weight average molecular weight of 10,000 or less may be 100 to 9,000, or 300 to 7,000, from the viewpoint of heat resistance and fluidity. The method for measuring the weight average molecular weight is the same as the method for measuring the weight average molecular weight of a high molecular weight component having a weight average molecular weight of more than 10,000, which will be described later.

(Hardening agent)
Examples of the curing agent include phenolic resin-based curing agents, acid anhydride-based curing agents, amine-based curing agents, imidazole-based curing agents, phosphine-based curing agents, azo compounds, and organic peroxides.

(i) Phenol Resin Curing Agent The phenol resin curing agent is not particularly limited as long as it has two or more phenolic hydroxyl groups in the molecule. For example, phenol novolac, cresol novolac, phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane type polyfunctional phenol, and various polyfunctional phenol resins can be used as the phenol resin curing agent. These can be used alone or as a mixture of two or more kinds.

The equivalent ratio of the phenolic resin-based curing agent to the epoxy resin (phenolic hydroxyl group/epoxy group, molar ratio) may be 0.3 to 1.5, 0.4 to 1.0, or 0.5 to 1.0 from the viewpoint of good curing properties, adhesion, and storage stability. When the equivalent ratio is 0.3 or more, the curing properties tend to be improved and the adhesive strength tends to be further improved, and when it is 1.5 or less, there is no excess of unreacted phenolic hydroxyl groups remaining, the water absorption rate is kept low, and insulation reliability tends to be further improved.

(ii) Acid anhydride-based curing agent Examples of the acid anhydride-based curing agent include methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, and ethylene glycol bisanhydrotrimellitate. These may be used alone or in combination of two or more.

The equivalent ratio of the acid anhydride curing agent to the epoxy resin (acid anhydride group/epoxy group, molar ratio) may be 0.3 to 1.5, 0.4 to 1.0, or 0.5 to 1.0 from the viewpoint of good curability, adhesion, and storage stability. When the equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be further improved, and when it is 1.5 or less, there is no excess unreacted acid anhydride remaining, the water absorption rate is kept low, and insulation reliability tends to be further improved.

(iii) Amine-Based Curing Agent As the amine-based curing agent, for example, dicyandiamide can be used.

The equivalent ratio of the amine-based curing agent to the epoxy resin (amine/epoxy group, molar ratio) may be 0.3 to 1.5, 0.4 to 1.0, or 0.5 to 1.0 from the viewpoint of good curability, adhesion, and storage stability. When the equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be further improved, and when it is 1.5 or less, no excessive unreacted amine remains, and the insulation reliability tends to be further improved.

(iv) Imidazole-Based Curing Agents Examples of imidazole-based curing agents include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6 -[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins and imidazoles. Among these, from the viewpoint of excellent curing properties, storage stability and connection reliability, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole may be selected. These may be used alone or in combination of two or more kinds. They may also be microencapsulated to form latent curing agents.

The content of the imidazole-based curing agent may be 0.1 to 20 parts by mass, or 0.1 to 10 parts by mass, per 100 parts by mass of the epoxy resin. If the content of the imidazole-based curing agent is 0.1 parts by mass or more, the curing property tends to be improved, and if it is 20 parts by mass or less, the semiconductor adhesive is unlikely to cure before the metal bond is formed, so that poor connection tends to be unlikely to occur.

(v) Phosphine-Based Curing Agents Examples of phosphine-based curing agents include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra(4-methylphenyl)borate, and tetraphenylphosphonium(4-fluorophenyl)borate.

The content of the phosphine-based curing agent may be 0.1 to 10 parts by mass, or 0.1 to 5 parts by mass, per 100 parts by mass of the epoxy resin. If the content of the phosphine-based curing agent is 0.1 parts by mass or more, the curing property tends to be improved, and if it is 10 parts by mass or less, the semiconductor adhesive is unlikely to cure before the metal bond is formed, so that poor connection tends to be unlikely to occur.

The phenolic resin-based hardener, acid anhydride-based hardener, and amine-based hardener can each be used alone or in a mixture of two or more. The imidazole-based hardener and phosphine-based hardener can each be used alone, but can also be used together with the phenolic resin-based hardener, acid anhydride-based hardener, or amine-based hardener.

(vi) Organic peroxides Examples of organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and peroxyesters. From the viewpoint of storage stability, the organic peroxides may be selected from hydroperoxides, dialkyl peroxides, and peroxyesters. Furthermore, from the viewpoint of heat resistance, the organic peroxides may be selected from hydroperoxides and dialkyl peroxides.

The content of the organic peroxide may be 0.5 to 10% by mass, or 1 to 5% by mass, based on the total mass of the (meth)acrylic compound. If it is 0.5% by mass or more, curing tends to proceed sufficiently, while if it is 10% by mass or less, curing tends to proceed too quickly, resulting in an increase in the number of reaction points, which in turn leads to shorter molecular chains and residual unreacted groups, which tends to prevent a decrease in reliability.

The above organic peroxides can be used alone or as a mixture of two or more.

The combination of the epoxy resin and (meth)acrylic compound with the curing agents (i) to (vi) is not particularly limited as long as the curing proceeds. The curing agent to be combined with the epoxy resin may be selected from phenol and imidazole, acid anhydride and imidazole, amine and imidazole, or imidazole alone, from the viewpoints of handling, storage stability, and curing properties. Since productivity improves when the connection is made in a short time, imidazole, which has excellent fast curing properties, may be used alone. Since volatile components such as low molecular weight components can be suppressed by curing in a short time, it is also possible to suppress the generation of voids. The curing agent to be combined with the (meth)acrylic compound may be an organic peroxide, from the viewpoints of handling and storage stability.

The curing reaction rate may be 80% or more, or 90% or more. If the curing reaction rate at 200°C (below the solder melting temperature)/5s is 80% or more, the solder is less likely to flow or splash when connected (above the solder melting temperature), and connection failures and poor insulation reliability tend not to occur.

The curing system may be a radical polymerization system. For example, as a compound with a weight average molecular weight of 10,000 or less, a radical polymerization (meth)acrylic compound (acrylic-peroxide curing system) is preferable compared to an anionic polymerization epoxy resin (epoxy-curing agent curing system). The acrylic curing system has a higher curing reaction rate, so it is easier to suppress voids and easier to suppress the flow and scattering of metal at the connection part. If an anionic polymerization epoxy resin is contained, it may be difficult to achieve a curing reaction rate of 80% or more. When an epoxy resin is used in combination, the epoxy resin may be 20 parts by mass or less for 80 parts by mass of the (meth)acrylic compound. The acrylic curing system may be used alone.

［式中、Ｒ^１はアルキル基又はフェニル基を示し、Ｒ^２はアルキレン基を示す。］ (Silanol Compound)
The silanol compound is represented by the following general formula (1).

[In the formula, R ¹ represents an alkyl group or a phenyl group, and R ² represents an alkylene group.]

The silanol compound may be solid at 25°C from the viewpoint of heat resistance. ^R1 may be an alkyl group or a phenyl group from the viewpoint of heat resistance and fluidity. It may be a mixture of an alkyl group and a phenyl group. Examples of groups represented by ^R1 include phenyl, propyl, phenylpropyl, and phenylmethyl groups. ^R2 is not particularly limited. It may be an alkylene group having a weight average molecular weight of 100 to 5000 from the viewpoint of heat resistance. It may be a trifunctional silanol from the viewpoint of high reactivity (strength of the cured product).

By adding a silanol compound to semiconductor adhesives, fluidity is improved, leading to improved void suppression and high connectivity. Improved fluidity (reduced viscosity) makes it easier to eliminate voids that are trapped during chip contact. Using a silanol compound with high heat resistance (small thermal weight loss) can further suppress the occurrence of voids. Small thermal weight loss means less volatile matter, which reduces voids and also improves reliability (reflow resistance).

The content of the silanol compound may be 2-20% by mass based on the total amount of the semiconductor adhesive, and from the viewpoint of high fluidity and hardened strength (adhesive strength, etc.), it may be 2-10% by mass or 2-9% by mass. If the content is 2% by mass or more, the effect (high fluidity) is likely to be realized, and if it is 20% by mass or less, the hardened strength increases and high adhesive strength tends to be realized. If the content is relatively small, the proportion of the hardened epoxy resin or acrylic resin increases, and it is presumed that higher adhesive strength is realized.

(High molecular weight component having a weight average molecular weight of more than 10,000)
Examples of the high molecular weight component having a weight average molecular weight of more than 10,000 include epoxy resin, phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, acrylic resin, polyester resin, polyethylene resin, polyethersulfone resin, polyetherimide resin, polyvinyl acetal resin, urethane resin, acrylic rubber, etc. Among them, epoxy resin, phenoxy resin, polyimide resin, acrylic resin, acrylic rubber, cyanate ester resin, polycarbodiimide resin, etc., which are excellent in heat resistance and film formability, may be selected. Furthermore, epoxy resin, phenoxy resin, polyimide resin, acrylic resin, acrylic rubber, which are excellent in heat resistance and film formability, may be selected. These high molecular weight components can be used alone or as a mixture or copolymer of two or more kinds.

When the semiconductor adhesive contains an epoxy resin, the mass ratio of the high molecular weight component having a weight average molecular weight of more than 10,000 to the epoxy resin is not particularly limited. Since the film shape is easily maintained, the epoxy resin may be 0.01 to 5 parts by mass, 0.05 to 4 parts by mass, or 0.1 to 3 parts by mass per part by mass of the high molecular weight component having a weight average molecular weight of more than 10,000. If this mass ratio is 0.01 parts by mass or more, the curing property tends to be improved and the adhesive strength tends to be further improved. If this mass ratio is 5 parts by mass or less, the film-forming property and the membrane-forming property tend to be particularly excellent.

When the semiconductor adhesive contains a (meth)acrylic compound, the mass ratio of the high molecular weight component having a weight average molecular weight of more than 10,000 to the (meth)acrylic compound is not particularly limited. The (meth)acrylic compound may be 0.01 to 10 parts by mass, 0.05 to 5 parts by mass, or 0.1 to 5 parts by mass per part by mass of the high molecular weight component having a weight average molecular weight of more than 10,000. If this mass ratio is 0.01 parts by mass or more, the curing property tends to be improved and the adhesive strength tends to be further improved. If this mass ratio is more than 10 parts by mass, the film formability tends to be particularly excellent.

The glass transition temperature (Tg) of the high molecular weight component having a weight average molecular weight of more than 10,000 may be 120°C or less, 100°C or less, or 85°C or less, from the viewpoint of excellent adhesion of the semiconductor adhesive to the substrate and chip. If the Tg is 120°C or less, the adhesive composition is more likely to fill the unevenness of bumps formed on a semiconductor chip, electrodes or wiring patterns formed on a substrate, etc., and therefore air bubbles are less likely to remain and voids are less likely to occur. The above Tg is the Tg measured using a DSC (PerkinElmer DSC-7 type) under the conditions of a sample amount of 10 mg, a heating rate of 10°C/min, and a measurement atmosphere of air.

The weight average molecular weight of the high molecular weight component having a weight average molecular weight of more than 10,000 is more than 10,000 in polystyrene equivalent, but may be 30,000 or more, 40,000 or more, or 50,000 or more in order to show better film formability by itself. When the weight average molecular weight exceeds 10,000, the film formability tends to be particularly excellent. In this specification, the weight average molecular weight means the weight average molecular weight measured in polystyrene equivalent using high performance liquid chromatography (Shimadzu Corporation C-R4A).

Semiconductor adhesives can contain flux components, i.e., flux activators, which are compounds that exhibit flux activity (activity to remove oxides and impurities). Examples of flux activators include nitrogen-containing compounds with unshared electron pairs, such as imidazoles and amines, carboxylic acids, phenols, and alcohols. Compared to alcohols, organic acids tend to exhibit stronger flux activity and improve connectivity. Carboxylic acids can further improve connectivity and stability.

A filler may be blended into the semiconductor adhesive to control the viscosity and physical properties of the cured product, and to suppress the generation of voids and moisture absorption rate when semiconductor chips are connected to each other or when a semiconductor chip is connected to a substrate. Examples of insulating inorganic fillers include glass, silica, alumina, titanium oxide, carbon black, mica, boron nitride, etc. Among them, from the viewpoint of handleability, silica, alumina, titanium oxide, boron nitride, etc. may be selected, and from the viewpoint of shape uniformity (handleability), silica, alumina, boron nitride may be selected. Examples of whiskers include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, boron nitride, etc. Examples of resin fillers that can be used include polyurethane, polyimide, methyl methacrylate resin, methyl methacrylate-butadiene-styrene copolymer resin (MBS), etc. These fillers and whiskers can be used alone or as a mixture of two or more types. There are no particular restrictions on the shape, particle size, and amount of the filler.

From the viewpoint of improving dispersibility and adhesive strength, the filler may be surface-treated. Examples of surface treatments include glycidyl-based (epoxy-based), amine-based, phenyl-based, phenylamino-based, acrylic-based, vinyl-based, etc.

These fillers and whiskers can be used alone or as a mixture of two or more types. There are no particular restrictions on the shape, particle size, or amount of the filler. In addition, the physical properties may be appropriately adjusted by surface treatment.

With regard to particle size, the average particle size may be 1.5 μm or less from the viewpoint of preventing jamming during flip chip connection, and the average particle size may be 1.0 μm or less from the viewpoint of visibility (transparency).

The surface treatment may be a silane treatment using a silane compound such as an epoxy silane, amino silane, or acrylic silane, because this is easy to perform.

The surface treatment agent may be a compound selected from glycidyl-based, phenylamino-based, acrylic-based, and methacrylic-based compounds from the viewpoint of excellent dispersibility and flowability and further improving adhesive strength. The surface treatment agent may be a compound selected from phenyl-based, acrylic-based, and methacrylic-based compounds from the viewpoint of storage stability.

Compared to inorganic fillers, resin fillers can impart flexibility at high temperatures such as 260°C, making them suitable for improving reflow resistance. In addition, the flexibility they impart is also effective in improving film formability.

From the viewpoint of insulation reliability, the filler may be insulating. The adhesive may be a semiconductor adhesive that does not contain conductive metal fillers such as silver fillers or solder fillers.

The amount of filler may be 30 to 90% by mass, or 40 to 80% by mass, based on the total solid content of the semiconductor adhesive. If the amount is 30% by mass or more, heat dissipation is likely to be improved and the generation of voids and moisture absorption rate tend to be further suppressed. If the amount is 90% by mass or less, the viscosity increases, making it easier to suppress a decrease in the fluidity of the adhesive composition and the biting (trapping) of the filler into the connection, and therefore connection reliability tends to be further improved.

The semiconductor adhesive may further contain ion trappers, antioxidants, silane coupling agents, titanium coupling agents, leveling agents, etc. These may be used alone or in combination of two or more. The amounts of these additives may be adjusted as appropriate so that the effects of each additive are expressed.

Semiconductor adhesives can be used for bonding at high temperatures of over 200°C. They are also particularly effective with flip-chip packages, where connections are made by melting metals such as solder.

The semiconductor adhesive may be in film form. Being in film form tends to improve productivity.

An example of a method for producing a semiconductor adhesive (film-like) is as follows. A high molecular weight component with a weight average molecular weight of more than 10,000, a compound with a weight average molecular weight of 10,000 or less, a curing agent, a filler, other additives, etc. are added to an organic solvent, and dissolved or dispersed by stirring, mixing, kneading, etc. to prepare a resin varnish. The resin varnish is then applied to a base film that has been subjected to a release treatment using a knife coater, roll coater, applicator, die coater, comma coater, etc., and the organic solvent is reduced by heating to form a film-like adhesive on the base film. Alternatively, the semiconductor adhesive may be formed on a wafer by spin-coating the resin varnish on a wafer or the like to form a film before reducing the organic solvent by heating, and then drying the solvent.

There are no particular limitations on the substrate film, so long as it has heat resistance sufficient to withstand the heating conditions used to volatilize the organic solvent. Examples of substrate films include polyester films, polypropylene films, polyethylene terephthalate films, polyimide films, polyetherimide films, polyethylene naphthalate films, and polymethylpentene films. The substrate film is not limited to a single layer of these films, and may be a multilayer film made of two or more materials.

The conditions for volatilizing the organic solvent from the applied resin varnish may be, for example, heating at 50 to 200°C for 0.1 to 90 minutes. If there is no effect on voids and viscosity adjustment after mounting, the conditions may be such that the organic solvent volatilizes to 1.5 mass % or less.

The melt viscosity of the semiconductor adhesive during the first step (pre-bonding), in which bonding is performed at a temperature (80 to 130°C) lower than the melting point of the connection bump 30 or bump 32, may be 6000 Pa·s or less, 5500 Pa·s or less, 5000 Pa·s or less, or 4000 Pa·s or less to increase fluidity and to better eliminate entrapment voids. However, if the melt viscosity is too low, the resin tends to creep up the side of the chip and adhere to the bonding tool, reducing productivity. Therefore, the melt viscosity during pre-bonding may be 1000 Pa·s or more. The melt viscosity can be measured, for example, using a rheometer (MCR301, manufactured by Anton Paar Japan).

<Sealing resin>
The encapsulating resin is not particularly limited as long as it is a resin that can be used for encapsulating a semiconductor device, and examples of such resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin, naphthalene diol type epoxy resin, hydrogenated bisphenol A type epoxy resin, and glycidylamine type epoxy resin.

The present invention will be explained below using examples, but the present invention is not limited to these.

<Preparation of film adhesive>
The compounds used are shown below.
(i) High molecular weight component having a weight average molecular weight of more than 10,000: Phenoxy resin (Tohto Kasei Co., Ltd., ZX-1356-2, Tg: about 71°C, Mw: about 63,000)
(ii) Compound with a weight average molecular weight of 10,000 or less: Epoxy resin Triphenolmethane skeleton-containing multifunctional solid epoxy (Mitsubishi Chemical Corporation, EP1032H60)
Bisphenol F type liquid epoxy (Mitsubishi Chemical Corporation, YL983U)
(iii) Curing agent: 2,4-diamine-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct (Shikoku Chemical Industry Co., Ltd., 2MAOK-PW)
(iv) Inorganic filler: Silica filler (Admatechs Co., Ltd., SE2050, average particle size 0.5 μm)
Epoxy silane surface-treated silica filler (Admatechs Co., Ltd., SE2050SEJ, average particle size 0.5 μm)
Methacrylic surface-treated nanosilica filler (Admatechs Co., Ltd., YA050C-SM, hereinafter referred to as SM nanosilica, average particle size approximately 50 nm)
(v) Resin Filler Organic Filler (manufactured by Rohm and Haas Japan, Inc., EXL-2655: core-shell type organic fine particles)
(vi) Fluxing agent: 2-methylglutaric acid (Aldrich, melting point: about 77° C.)

(Method of producing film-like adhesive)
An organic solvent (methyl ethyl ketone) was added to the epoxy resin, inorganic filler, resin filler, and flux agent in the mass ratios shown in Table 1 so that the NV was 60% (40% by mass of the solvent, and all of the components constituting the adhesive such as liquid components, solid components, and fillers were 60% by mass). Then, beads of φ1.0 mm and φ2.0 mm were added in the same mass as the solid content, and the mixture was stirred for 30 minutes with a bead mill (Fritsch Japan Co., Ltd., planetary fine grinder P-7). Then, a high molecular weight component was added, and the mixture was stirred again for 30 minutes with a bead mill. After stirring, a curing agent was added and stirred, and the beads used were then removed by filtration to obtain two types of resin varnishes.

Each of the prepared resin varnishes was applied to a substrate film whose surface had been treated for release using a small precision coating device (manufactured by Yasui Seiki Co., Ltd.), and the applied resin varnish was dried (70°C/10 min) in a clean oven (manufactured by Espec Corporation) to obtain film-like adhesive A.

<Manufacturing of semiconductor device>
Example 1
Step 1: The film-like adhesive prepared above was cut out (8 mm × 8 mm × 0.045 mm ^t ) and attached onto a substrate (20 mm × 27 mm, 0.41 mm thick, connection metal: Cu (OSP treatment), product name: HCTEG-P1180-02, manufactured by Hitachi Chemical Electronics Co., Ltd.). On top of that, a semiconductor chip with solder bumps (chip size: 7.3 mm × 7.3 mm × 0.15 mm ^t , bump height: copper pillar + solder total about 45 μm, number of bumps 328 pins, pitch 80 μm, product name: SM487A-HC-PLT, manufactured by Sumitomo Corporation Kyushu Co., Ltd.) was temporarily bonded using a thermocompression bonder (FCB3, manufactured by Panasonic Corporation) under the conditions of stage temperature 80 ° C., temporary bonding temperature 130 ° C., and temporary bonding time 2 seconds.
Step 2: The semiconductor package (temporary connection body) that had been temporarily pressure-bonded was sealed on the top surface of the chip with a sealing resin (product name: CEL-400ZHF40-MANG, manufactured by Hitachi Chemical Co., Ltd.) using a molding device (manufactured by Techno Multi-C Corporation) to form a sealed body (sealed temporary connection body).
Step 3 (or step 4): The obtained sealed body was subjected to a heat treatment using the above-mentioned thermocompression machine (FCB3, manufactured by Panasonic Corporation) at a stage temperature of 80° C. and a compression temperature of 280° C. to produce a sealed connection body.
Step 4 (or step 3): The sealing material on the top surface of the chip of the obtained sealed connection body was ground using a backgrinding device (DAG810, DISCO Corporation) to produce a semiconductor device with an exposed back surface of the chip (the surface opposite to the surface having the bumps).

Example 2
As shown in Table 2, a semiconductor device was produced in the same manner as in Example 1, except that the heat treatment in step 3 was performed using a reflow apparatus (hot air nitrogen reflow oven SNR-1065GT, manufactured by Senju Metal Industry Co., Ltd.).

Example 3
As shown in Table 2, a semiconductor device was fabricated in the same manner as in Example 1, except that the order of steps 3 and 4 was reversed and the heat treatment (thermocompression bonding) was performed after grinding the sealing body.

Example 4
As shown in Table 2, a semiconductor device was fabricated in the same manner as in Example 2, except that the order of steps 3 and 4 was reversed and the heat treatment (reflow) was performed after grinding the sealing body.

(Comparative Example 1)
As shown in Table 2, a semiconductor device was fabricated in the same manner as in Example 1, except that step 4 was not performed.

(Comparative Example 2)
As shown in Table 2, a semiconductor device was fabricated in the same manner as in Example 2, except that step 4 was not performed.

<Evaluation>
(Melt Viscosity Evaluation)
The melt viscosity of the film-like adhesive prepared above was measured in step 1 (temporary bonding temperature: 80 to 130°C) using a rheometer (MCR301, manufactured by Anton Paar Japan) and a jig (a disposable plate (diameter 8 mm) and a disposable sample dish) under conditions of a sample thickness of 400 μm, a heating rate of 10°C/min, and a frequency of 1 Hz. The results are shown in Table 2.

(Moisture absorption reliability test)
The semiconductor device prepared above was left to stand in a thermohygrostat (PR-2KP, manufactured by Espec Corporation) for 168 hours under conditions of 80°C and 65% RH to absorb moisture. The semiconductor device after moisture absorption was heat-treated in a reflow furnace at 260°C for 30 seconds. The inside of the semiconductor device after moisture absorption and heat treatment (reflow) was observed using an ultrasonic observation device (INSIGHT-300, manufactured by Insight Corporation) to confirm the presence or absence of peeling between each member (between the substrate and the adhesive layer, between the semiconductor chip and the adhesive layer, between the semiconductor chip and the encapsulant, between the substrate and the encapsulant, and between the encapsulant and the adhesive layer). When peeling was not observed at any point, it was marked as "absent", and when peeling was observed at any point, it was marked as "present". The results are shown in Table 2.

10...semiconductor chip, 12...semiconductor chip body, 15...wiring (connection portion), 20...substrate (wired circuit board), 22...substrate body, 30...connection bump, 32...bump (connection portion), 34...through electrode, 40...adhesive layer, 50...interposer, 60...sealing resin, 100, 200, 300, 400, 500, 600, 700...semiconductor device.

Claims (13)

A method for manufacturing a semiconductor device comprising a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other, or a semiconductor device comprising a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other, comprising:
The connection portion is made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection portion so that the connection portions are in contact with each other, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of heating the temporary sealed connection body at a temperature equal to or higher than the melting point of the metal of the connection portion to obtain a sealed connection body;
(d) a fourth step of grinding at least a portion of the sealing resin in the sealed connection body;
A manufacturing method of a semiconductor device comprising: A method for manufacturing a semiconductor device comprising a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other, or a semiconductor device comprising a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other, comprising:
The connection portion is made of metal,
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection portion so that the connection portions are in contact with each other, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of grinding at least a portion of the sealing resin in the sealed temporary connection body;
(d) a fourth step of heating the temporary sealed connection body at a temperature equal to or higher than the melting point of the metal of the connection portion to obtain a sealed connection body;
A manufacturing method of a semiconductor device comprising: A method for manufacturing a semiconductor device comprising a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other via connection bumps, or a semiconductor device comprising a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other via connection bumps,
the connection portion and the connection bump are made of metal;
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection bumps so that the connection portions of the respective chips are in contact with the connection bumps, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of heating the encapsulated temporary connection body at a temperature equal to or higher than the melting point of the metal of the connection bumps to obtain an encapsulated connection body;
(d) a fourth step of grinding at least a portion of the sealing resin in the sealed connection body;
A manufacturing method of a semiconductor device comprising: A method for manufacturing a semiconductor device comprising a semiconductor chip having a connection portion and a wiring circuit board having a connection portion, the connection portions being electrically connected to each other via connection bumps, or a semiconductor device comprising a plurality of semiconductor chips having connection portions, the connection portions being electrically connected to each other via connection bumps,
the connection portion and the connection bump are made of metal;
(a) a first step of bonding the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, with a semiconductor adhesive interposed therebetween, at a temperature lower than the melting point of the metal of the connection bumps so that the connection portions of the respective chips are in contact with the connection bumps, thereby obtaining a temporary connection body;
(b) a second step of sealing at least a portion of the temporary connection body with a sealing resin to obtain a sealed temporary connection body;
(c) a third step of grinding at least a portion of the sealing resin in the sealed temporary connection body;
(d) a fourth step of heating the encapsulated temporary connection body at a temperature equal to or higher than the melting point of the metal of the connection bumps to obtain an encapsulated connection body;
A manufacturing method of a semiconductor device comprising: The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein in the step of grinding off at least a portion of the sealing resin, grinding is performed until the surface of the semiconductor chip opposite the surface having the connection portion is exposed. The method for manufacturing a semiconductor device according to any one of claims 1 to 5, wherein in the first step, the semiconductor chip and the wiring circuit board, or the semiconductor chips themselves, are sandwiched between a pair of opposing pressing members and heated and pressurized to bond them together. The method for manufacturing a semiconductor device according to any one of claims 1 to 6, wherein the adhesive for semiconductors contains a compound having a weight average molecular weight of 10,000 or less and a curing agent, and has a melt viscosity of 6,000 Pa·s or less at 80 to 130°C. The method for manufacturing a semiconductor device according to any one of claims 1 to 7, wherein the adhesive for a semiconductor contains a compound having a weight average molecular weight of 10,000 or less, a curing agent, and a silanol compound represented by the following general formula (1):

[In the formula, R ¹ represents an alkyl group or a phenyl group, and R ² represents an alkylene group.] The method for producing a semiconductor device according to claim 8 , wherein the R ¹ is a phenyl group. The method for manufacturing a semiconductor device according to claim 8 or 9, wherein the silanol compound is solid at 25°C. The method for manufacturing a semiconductor device according to any one of claims 1 to 10, wherein the semiconductor adhesive contains a high molecular weight component having a weight average molecular weight of more than 10,000. The method for manufacturing a semiconductor device according to claim 11, wherein the high molecular weight component has a weight average molecular weight of 30,000 or more and a glass transition temperature of 100°C or less. The method for manufacturing a semiconductor device according to any one of claims 1 to 12, wherein the semiconductor adhesive is in the form of a film.

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