JP2004221555A - Semiconductor element with film, semiconductor device, and method of manufacturing the same - Google Patents

Abstract

To reduce the size of a semiconductor device including a semiconductor element.
SOLUTION: A step of attaching a film 104 to an entire surface opposite to an element forming surface of a semiconductor substrate 101 on which a plurality of elements are formed, and a step of selectively removing the film 104 with a predetermined width along an outer edge of each element. And at the same time as or after the step of selectively removing the film 104, the semiconductor substrate 101 is cut along the outer edge, and the plurality of semiconductor elements 102 to which the film 104 formed smaller than the formation region is attached. The semiconductor device 106 with a film is manufactured by the step of dividing into two. A semiconductor device is manufactured by laminating a plurality of semiconductor elements with a film 106 thus formed.
[Selection diagram] Fig. 1

Description

  The present invention relates to a semiconductor element with a film, a semiconductor device, and a method for manufacturing the same.

  2. Description of the Related Art In recent years, with the demand for higher functionality and lighter, thinner and smaller electronic devices, high-density integration and high-density mounting of electronic components have been progressing. Semiconductor packages used in these electronic devices have become smaller and have more pins, and mounting substrates for mounting electronic components including the semiconductor packages have also become smaller. Furthermore, in order to enhance the storage in electronic devices, a rigid-flex board, in which a rigid board and a flexible board are laminated and integrated to be bent, has been used as a mounting board.

  With the miniaturization of the semiconductor package, a new method of area mounting type such as BGA (Ball Grid Array) or CSP (Chip Scale Package) in which a chip is mounted on a circuit board has been proposed. In these semiconductor packages, a wire bonding method, a TAB (Tape Automated Bonding) method, an FC (Flip Chip) method, or the like is used as an electrical connection method between the electrode of the semiconductor chip and the terminal of the substrate. Here, the substrate is also called a substrate for a semiconductor package, is made of various materials such as plastic and ceramics, and has a function of a lead frame of a conventional semiconductor package.

  However, in the conventional method as described above, only one semiconductor element can be accommodated in one semiconductor package, and there is naturally a limit to miniaturization of the semiconductor package. For this reason, a method has been proposed in which a plurality of semiconductor elements are stacked and housed in one semiconductor package to improve the mounting density.

  Incidentally, the semiconductor element needs to be electrically connected to an external lead frame or substrate. The semiconductor element provided directly above the substrate may be connected to the substrate by a flip chip method, but the semiconductor element provided in the upper layer has an electrode pad formed on the element formation surface, and via the electrode pad. It is electrically connected to the substrate. The electrode pad and the substrate are connected by, for example, gold wire bonding by wire bonding.

  When a plurality of semiconductor elements are stacked, the upper semiconductor element is formed on the lower layer in order to expose the electrode pads of the lower semiconductor element and to avoid interference between the gold wire bonding by the lower wire bonding and the upper semiconductor element. It must be formed smaller than a semiconductor element, and mounting restrictions are increasing.

  In order to solve the above problems, for example, in Patent Document 1, when stacking semiconductor chips of substantially the same size, a concave portion is formed by locally grinding the edge of an upper semiconductor chip, and forming a concave portion. There is disclosed a technology for connecting an electrode pad of a lower semiconductor chip and a bonding wire using a space.

Patent Document 2 discloses a technique in which a part of an upper semiconductor element is ground and then a semiconductor element is stacked so as not to interfere with a wire bonding portion of a lower semiconductor element.
JP-A-10-70232 JP 2000-58742 A

  However, the conventional method has problems such as an increase in package size and a complicated process.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for reducing the size of a semiconductor device including a semiconductor element. Another object of the present invention is to provide a technique for easily manufacturing such a semiconductor device.

  According to the present invention, the semiconductor device includes a semiconductor device and a film bonded to the surface opposite to the device forming surface of the semiconductor device, and the film is formed smaller than the semiconductor device on the bonding surface bonded to the semiconductor device. A semiconductor device with a film is provided.

  Here, the film has a thickness such that when a plurality of such semiconductor elements with a film are stacked, bonding wires extending from the element formation surface of the lower semiconductor element do not interfere with the upper semiconductor element. Have. Accordingly, when a plurality of semiconductor elements with a film are stacked, a stable stacked body can be manufactured without causing electrical interference with each other.

  According to the present invention, a wiring substrate, a first semiconductor element disposed on the wiring substrate so that the element formation surface is facing up, and a film adhered to the element formation surface of the first semiconductor element, A semiconductor device is provided, characterized in that the film is formed smaller than the first semiconductor element on an adhesion surface for adhering to the first semiconductor element.

  Thereby, even if another semiconductor element is laminated on the upper layer of the film, the first semiconductor element in the lower layer and the other semiconductor element do not electrically interfere with each other, and a stable laminate can be manufactured. . Here, the wiring board is an interposer or a printed board.

  The semiconductor device of the present invention can further include a second semiconductor element bonded to the first semiconductor element via a film, and the surface opposite to the element forming surface of the second semiconductor element is bonded to the film. Good.

  Here, the second semiconductor element can be larger than the first semiconductor element. In the semiconductor device of the present invention, the film formed on the first semiconductor element is formed smaller than the first semiconductor element. Therefore, even if the film functions as a spacer and the second semiconductor element 102 is larger than the first semiconductor element, a gap is generated between the first semiconductor element and the second semiconductor element. Accordingly, even when a bonding wire or the like extending from an electrode pad provided on the element formation surface of the lower first semiconductor element is connected to an external terminal, the bonding wire and the upper semiconductor element do not interfere with each other, and Can be manufactured stably.

  According to the present invention, a semiconductor device with a film including a semiconductor element and a film bonded to a surface opposite to the element forming surface of the semiconductor element, and a film formed smaller than the semiconductor element on an adhesive surface bonded to the semiconductor element is provided. A stacked semiconductor device is provided.

  Thus, by making the film smaller than the semiconductor element, when the semiconductor elements with a film are stacked, a gap can be created between the lower semiconductor element and the upper semiconductor element, and the lower semiconductor element It is possible to prevent the extending bonding wire and the like from interfering with the upper semiconductor element.

  According to the present invention, a step of attaching a film to the entire surface opposite to the element forming surface of the semiconductor substrate on which a plurality of elements are formed, and a step of selectively removing the film at a predetermined width along the outer edge of each element A plurality of semiconductor elements to which a semiconductor substrate is cut along an outer edge at the same time as or after the step of selectively removing a film, and a film formed smaller than a region surrounded by the outer edge is attached. And a method for producing a semiconductor device with a film.

  As described above, unnecessary portions of the film are removed after the film is attached to the semiconductor substrate, and the semiconductor substrate is divided at the same time or thereafter, so that a semiconductor device with a film can be efficiently manufactured.

  In the method of manufacturing a semiconductor device with a film according to the present invention, in the step of selectively removing the film, the film having a predetermined width can be removed from the opposite surface side of the semiconductor substrate by the first cutter.

  In the method for manufacturing a semiconductor device with a film according to the present invention, in the step of dividing the semiconductor device into semiconductor devices, the semiconductor substrate can be cut by a second cutting machine that is narrower than the first cutting machine. In this case, the step of dividing into semiconductor elements may be performed after the step of selectively removing the film, but these steps may be performed simultaneously. After the step of selectively removing the film, the cutting of the semiconductor substrate can be performed from the element forming surface or the opposite surface of the semiconductor substrate, but substantially simultaneously with the step of removing the film with the first cutting machine, From the opposite side with a second cutting machine. Thereby, a semiconductor element with a film can be manufactured efficiently. Further, by using a cutting machine to cut from both sides opposite to the element forming surface of the semiconductor substrate, roughening of the cut surface can be prevented, and the cut surface can be in a good state.

  According to the present invention, a semiconductor device with a film including a semiconductor element and a film bonded to a surface opposite to the element forming surface of the semiconductor element, and a film formed smaller than the semiconductor element on an adhesive surface bonded to the semiconductor element is provided. A method for manufacturing a semiconductor device, comprising a step of stacking a plurality of semiconductor devices, is provided.

  As described above, according to the present invention, a package accommodating a plurality of semiconductor elements can be obtained without being limited by the size of the semiconductor elements accommodated.

  According to the present invention, a semiconductor device including a semiconductor element can be reduced in size. Further, according to the present invention, such a semiconductor device can be easily manufactured.

FIG. 1 is a process sectional view illustrating a method for manufacturing a semiconductor device with a film according to an embodiment of the present invention.
In this embodiment, as shown in FIG. 1F, a semiconductor element with a film 106 in which a film 104 is attached to a semiconductor element 102 is manufactured, and the semiconductor element with a film is laminated to manufacture a semiconductor device. . Here, the film 104 is formed to be smaller than the semiconductor element 102 on the bonding surface to be bonded to the semiconductor element 102. Thus, when the semiconductor elements with a film 106 are stacked, a gap is formed between the lower semiconductor element 102 and the upper semiconductor element 102. Therefore, when an electrode pad provided on the lower semiconductor element 102 and a substrate such as an external interposer are connected by a bonding wire, interference between the bonding wire and the upper semiconductor element 102 can be prevented.

  First, a semiconductor substrate 101 is prepared (FIG. 1A), and a film 104 is attached to the entire back surface opposite to the element formation surface (FIG. 1B). Here, the film 104 is an adhesive film for die bonding. The thickness of the film 104 is determined by the height of the functional surface of the lower semiconductor element 102 so that a bonding wire extending from the lower semiconductor element 102 does not contact the upper semiconductor element 102 when the film-attached semiconductor elements 106 are stacked. It can be greater than or equal to the difference in height at the top of the bonding wire. More preferably, the thickness of the film 104 can be made 50 μm or more larger than the difference between the height of the functional surface of the semiconductor element 102 and the height of the top of the bonding wire.

  As the film 104, for example, DF-402 (manufactured by Hitachi Chemical Co., Ltd.) can be used. The thickness of the film 104 is not particularly limited, but may be, for example, 10 μm or more and 200 μm or less. Such a film can be used by being appropriately laminated so as to have the above height.

  The film 104 can be attached to the semiconductor substrate 101 by an existing method such as a roll laminator, a vacuum elastic body press, and a vacuum laminator. In order to suppress the warpage of the semiconductor substrate 101, it is preferable that the semiconductor substrate 101 is attached at a temperature as low as possible using surface pressure, rather than using a roll.

  Subsequently, the film 104 is selectively removed (FIG. 1C). The film 104 is to be selectively removed so that the electrode pad of the lower semiconductor element 102 is exposed when the semiconductor element 106 with a film is laminated, and the bonding wire extending from the electrode pad does not interfere with the upper semiconductor element 102. Can be. As a method for removing the film 104, various methods can be used. For example, a method for partially removing the film 104 by attaching a rotating grindstone to a dicing machine can be used. Further, other known methods such as photolithography, plasma, sandblasting, and laser processing can also be used. When the film 104 is partially removed, a part of the back surface of the semiconductor substrate 101 may be removed at the same time.

  Thereafter, the semiconductor substrate 101 is divided into a plurality of semiconductor elements 102 (FIG. 1E). Cutting of the semiconductor substrate 101 can be performed by, for example, a dicing machine. As a result, a film-equipped semiconductor element 106 can be obtained in which the film 104 formed smaller than the semiconductor element 102 on the adhesive surface is attached to the surface opposite to the element formation surface of the semiconductor element 102 (FIG. 1F). . FIG. 2 is a perspective view showing the semiconductor element 106 with a film.

  In the present embodiment, as shown in FIG. 1C, by including the step of selectively removing the film 104, when a plurality of semiconductor elements 106 with a film are stacked, the semiconductor element 102 extends from the lower semiconductor element 102. The wiring and the upper semiconductor element 102 can be prevented from interfering with each other. Thus, a stacked body of semiconductor elements can be formed without considering the size of the semiconductor element 102 in the upper layer.

FIG. 3 is a plan view of the semiconductor substrate 101 to which the film 104 is attached, as viewed from the back.
In FIG. 3A, a broken line 120 indicates an outer edge of each element formed on the element formation surface of the semiconductor substrate 101. FIG. 3B is a diagram illustrating the semiconductor substrate 101 after the film 104 described with reference to FIG. 1D is selectively removed. The film 104 is partially removed at a predetermined width along the outer edge (broken line 120) of each element. After that, the semiconductor substrate 101 is cut along the outer edge of each element. Thus, the semiconductor device with film 106 as shown in FIG. 1F is obtained.

  FIG. 4 is a diagram showing a step of removing the film 104 and a step of cutting the semiconductor substrate 101. When removing the film 104 with the rotary grindstone 122 assembled to the dicing machine, the step of removing the film 104 and the step of cutting the semiconductor substrate 101 can be performed substantially simultaneously. In this case, as shown in the drawing, the film 104 is removed from the back surface of the semiconductor substrate 101 by the rotating grindstone 122, and the semiconductor substrate 101 is subsequently cut from the back surface of the semiconductor substrate 101 by the teeth 124 of the dicing machine. Thereby, the roughness of the cut surface can be reduced, and the process can be shortened. Alternatively, after removing the film 104 from the back surface of the semiconductor substrate 101 with the rotating grindstone 122, a fixing tape may be attached to the back surface of the semiconductor substrate 101, and the semiconductor substrate 101 may be cut from the element formation surface with the teeth 124 of a dicing machine. it can. By using the fixing tape, it is possible to prevent the semiconductor substrate 101 from being separated when the semiconductor substrate 101 is cut.

FIG. 5 is a process cross-sectional view showing a procedure for manufacturing a semiconductor device by laminating the semiconductor elements with a film 106 shown in FIGS. 1F and 2.
First, one semiconductor element with film 106 is placed on the interposer 108, and an electrode pad (not shown) formed on the element forming surface of the semiconductor element with film 106 and the interposer 108 are electrically connected with the bonding wire 110. (FIG. 5A). As the bonding wire 110, a metal such as gold or aluminum can be used.

  Subsequently, another semiconductor element with a film 106 is laminated on the semiconductor element with a film 106, and an electrode pad (not shown) formed on the element forming surface of the semiconductor element with a film 106 in the upper layer is bonded to an interposer 108 with a bonding wire. Electrical connection is made at 110 (FIG. 5B).

  Thereafter, the semiconductor element with film 106 laminated with the sealing material 114 is sealed and packaged by transfer molding or the like. As the sealing material 114, for example, an epoxy sealing resin such as EME-G770 (manufactured by Sumitomo Bakelite Co., Ltd.) can be used. Thereafter, a solder ball 112 is formed on the back surface of the interposer 108 (the surface opposite to the mounting surface of the semiconductor element 106 with a film). Thereby, the semiconductor device 100 having the configuration is obtained (FIG. 5C).

  Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

  A die bonding film (DF-402, Hitachi Chemical Co., Ltd.) having a thickness of 83 μm was attached by a roll laminator to the entire surface opposite to the element formation surface of the semiconductor substrate (200 μm thick) on which a plurality of elements were formed. Next, a film having a width of 500 μm was removed from the outer edge along the outer edge of each element formed on the semiconductor substrate by the rotating grindstone. Here, the width of the rotating grindstone was 1 mm.

  Thereafter, the semiconductor elements (7 mm × 8 mm) were singulated by using a dicing machine. Here, a dicing machine having a tooth width of 35 μm was used.

  The semiconductor element with the film is mounted on a printed wiring board having bonding fingers formed on the front surface and lands for mounting solder balls on the rear surface, and the semiconductor element and the printed wiring board are connected by gold wires using a wedge bonding technique. Connected.

  Furthermore, after another semiconductor element with a film is mounted on the semiconductor element with a film mounted on the printed wiring board by the above process, the upper layer semiconductor element and the printed wiring board are connected by a gold wire using a wedge bonding technique. did.

  Subsequently, the surface of the printed wiring board on which the two semiconductor elements were stacked and mounted was sealed with a sealing resin, and solder balls were mounted on the back surface to form a BGA package. The semiconductor device obtained in this manner was mounted on a printed wiring board, and operation was confirmed. As a result, it was confirmed that the semiconductor device normally operated.

The present invention also includes the following aspects.
[1] A semiconductor device comprising a die bonding film having an area smaller than that of the semiconductor device on the back surface of the functional surface of the semiconductor device.
[2] (A) a step of attaching an adhesive film for die bonding to the entire back surface of the functional surface of the semiconductor wafer, (B) a step of removing a predetermined portion of the adhesive film for die bonding, and (C) fragmenting the semiconductor wafer. A method of manufacturing a semiconductor device, comprising:
[3] A semiconductor device comprising a die bonding film having a smaller area than the semiconductor device on the back surface of the functional surface of the semiconductor device obtained by the manufacturing method according to [2].
[4] A semiconductor device including at least one semiconductor element including a die bonding film having an area smaller than that of the semiconductor element on the back surface of the functional surface of the semiconductor element according to [1] or [3].

It is a process sectional view showing a manufacturing method of a semiconductor device with a film in an embodiment of the invention. It is a perspective view which shows the semiconductor element with a film. It is the top view which looked at the semiconductor substrate to which the film was stuck from the back. It is a figure which shows the process of removing a film and the process of cutting a semiconductor substrate. It is process sectional drawing which shows the manufacturing method of a semiconductor device by laminating the semiconductor element with a film.

Explanation of reference numerals

Reference Signs List 100 semiconductor device 101 semiconductor substrate 102 semiconductor element 104 film 106 semiconductor element with film 108 interposer 110 bonding wire 112 solder ball 114 sealing material 122 rotating grindstone 124 dicing machine teeth

Claims (8)

A semiconductor element;
A film adhered to the surface opposite to the device forming surface of the semiconductor device,
Including
A semiconductor device with a film, wherein the film is formed to be smaller than the semiconductor element on an adhesion surface to be adhered to the semiconductor element. A wiring board,
A first semiconductor element disposed on the wiring board such that an element forming surface is on the top,
A film adhered to the element forming surface of the first semiconductor element,
Including
A semiconductor device, wherein the film is formed smaller than the first semiconductor element on an adhesion surface that adheres to the first semiconductor element. The semiconductor device according to claim 2,
Further comprising a second semiconductor element bonded to the first semiconductor element via the film,
A semiconductor device having a surface opposite to an element forming surface of the second semiconductor element adhered to the film.   A plurality of semiconductor elements with a film including a semiconductor element and a film bonded to the opposite surface of the element formation surface of the semiconductor element and bonded to the semiconductor element, and including a film formed smaller than the semiconductor element, were stacked. Semiconductor device. A step of attaching a film to the entire surface opposite to the element forming surface of the semiconductor substrate on which a plurality of elements are formed,
Selectively removing the film at a predetermined width along the outer edge of each element,
Simultaneously with or after the step of selectively removing the film, the semiconductor substrate is cut along the outer edge, and a plurality of films to which a film formed smaller than a region surrounded by the outer edge is attached. Dividing into semiconductor elements;
A method for manufacturing a semiconductor device with a film, comprising: The method for manufacturing a semiconductor device with a film according to claim 5,
In the step of selectively removing the film, a method for manufacturing a semiconductor device with a film, wherein the film having the predetermined width is removed from the opposite side of the semiconductor substrate by a first cutting machine. The method for manufacturing a semiconductor device with a film according to claim 6,
In the step of dividing into semiconductor elements, a method of manufacturing a semiconductor element with a film, wherein the semiconductor substrate is cut by a second cutting machine narrower than the first cutting machine. A plurality of semiconductor elements with a film including a semiconductor element and a film that is bonded to the surface opposite to the element formation surface of the semiconductor element and that is smaller than the semiconductor element on the bonding surface that is bonded to the semiconductor element are stacked. A method for manufacturing a semiconductor device, comprising the steps of:

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