JP4573472B2 - Hybrid integrated circuit device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a hybrid integrated circuit device, and in particular, substantially does not require a case material, melts and cures a pellet in which powder resin before heat curing is integrated and a reinforcing sheet is provided on the surface, thereby substantially covering the entire area of the hybrid integrated circuit substrate. The present invention relates to a hybrid integrated circuit device having a resin sealing body in which is sealed.
[0002]
[Prior art]
First, there is generally a hybrid integrated circuit device as shown in FIG. 4, for example, Japanese Patent Publication No. 61-55247.
[0003]
In other words, the hybrid integrated circuit device has a metal substrate 1, an insulating material 2 coated on the surface thereof, and conductive patterns 3 and 4 made of Cu adhered thereto, and the conductive patterns 3 and 4 are connected to the conductive patterns 3 and 4 via a heat sink HS. A circuit element 5 such as an electrically connected semiconductor element, a chip component 14 fixed to the conductive pattern 4 by solder, an external lead 6 fixed to the pad 3 which is a part of the conductive pattern via solder, and And a metal thin wire 7 for electrically connecting the circuit elements 5 and a resin 8 for molding them.
[0004]
That is, the back surface of the substrate 1 is exposed in consideration of heat dissipation.
[0005]
There are various sealing structures. First, as shown in FIG. 4, a metal substrate to which circuit elements 3 and 4 and external leads 6 are attached is prepared, and the case material 9 shown in FIG. This was realized by applying the resin 8 to the space formed by pasting and the case material 9 and the metal substrate 1.
[0006]
In the first sealing structure, it is necessary to prepare a space in which the case material 9 is bonded and the resin 8 can be injected, the workability is poor, the price is expensive, the package size is increased, and the resin sealing is performed. There was also a problem that heat dissipation through the stationary body was poor.
[0007]
Further, the second sealing structure is formed by preparing the hybrid integrated circuit substrate shown in FIG. 4, setting it in a mold, and injecting a resin into the space formed by the metal substrate 1 and the mold.
[0008]
In the second sealing structure, various molds must be prepared depending on the shape of the hybrid integrated circuit substrate and the lead shape, and there is a problem that it is difficult to reduce the thickness.
[0009]
Further, in the third sealing structure, the resin is applied directly on the metal substrate 1 of FIG. 4 or is sealed by dipping in a liquid resin.
[0010]
The third sealing structure is less time-consuming and less expensive than the first and second sealing structures, but the level of circuit elements mounted on the metal substrate 1 is high and low on the resin surface. There was a problem that unevenness was formed and the printability of the model name was poor. Further, when mounting on a printed circuit board or the like with an automatic mechanism of a suction mechanism, there is a problem that the hybrid integrated circuit device cannot be sucked due to unevenness of the resin surface.
[0011]
In view of the problems of each sealing structure described above, the inventor melts and cures a pellet in which a powder resin before thermosetting is integrated and a reinforcing sheet is provided on the surface to cover substantially the entire area of the hybrid integrated circuit board. It was proposed to use a sealed resin encapsulant.
[0012]
Specifically, first, a hybrid integrated circuit substrate 1 as shown in FIG. 4 is prepared.
[0013]
Next, the pellet 21 is disposed on the hybrid integrated circuit substrate 1 as shown in FIG. Here, the pellet 21 is formed by integrating a powdery resin 23 before thermosetting on a reinforcing sheet 22.
[0014]
The reinforcing sheet 22 needs to maintain flatness even after the resin 23 is thermally cured, and is preferably an epoxy-impregnated glass fiber or the like. A thin glass substrate or the like may also be used.
[0015]
In this state, the resin 23 is placed on, for example, a heater, melted at about 150 degrees, and then thermally cured.
[0016]
This completed drawing is shown in FIG. The above-described molten resin sinks due to its own weight or the weight of the reinforcing sheet, and simultaneously flows out from the end portions T1 and T2 of the reinforcing sheet to the peripheral end of the hybrid integrated circuit board 1 to form the sag portions 24 and 25.
[0017]
When the pellet 21 melts, the resin softens and flows so as to cover the entire surface of the hybrid integrated circuit board 1. Moreover, since the reinforcing sheet 22 is present on the surface, it can be cured while maintaining flatness. Therefore, the manufacturing process can be simplified, the cost can be reduced, and the printability and suction performance can be maintained. Moreover, the thickness of the resin sealing body 23 can also be reduced to half or less.
[0018]
[Problems to be solved by the invention]
When the resin sealing body 20 in which the above-described powder resin before thermosetting is integrated and the pellet 21 provided with the reinforcing sheet 22 on the surface is melt-cured to seal the substantially entire area of the hybrid integrated circuit board 1 is used, The case material 9 used for the conventional first sealing structure is also unnecessary, the mold used for the second sealing structure is also unnecessary, and the surface used for the third sealing structure is coated or dipped. The sealing resin is also eliminated, and the problems of conventional sealing structures are solved.
[0019]
However, as shown in FIG. 6, there occurs a defect in which the sealing resin body 20 melted from the pellet 21 flows out to the end face of the substrate 1 at the side where the external lead 6 is provided. The reason is that, as shown in FIG. 8, the sealing resin body 20 melted from the pellet 21 has a function of being rounded and spread by the action of the surface tension, and at the same time, the influence of the resin suction of the L-type external lead 6 also works. This is because the sealing resin body 20 easily flows on the side where the external lead 6 is provided.
[0020]
[Means for Solving the Problems]
The present invention has been made in view of the above-mentioned problems, and a hybrid integrated circuit board having a conductive pattern on its surface, a circuit element electrically connected to the conductive pattern, and a powder resin before thermosetting are integrated. A hybrid integrated circuit device having a resin sealing body that melts and cures a pellet provided with a reinforcing sheet on the surface and seals a substantial whole area of the hybrid integrated circuit substrate,
The pellet has a shape in which at least one side is notched inside the hybrid integrated circuit board, and the resin sealing body melted from the pellet is prevented from flowing out to the end face of the hybrid integrated circuit board. To do.
[0021]
In the present invention, by providing a shape in which one side of the pellet is notched inside the hybrid integrated circuit substrate, the fluidity at that side is controlled by utilizing the surface tension of the molten sealing resin body. A hybrid integrated circuit device that prevents the body from flowing out to the end face of the substrate is realized.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
An outline of the embodiment of the present invention will be described below with reference to FIG.
In addition, the same code | symbol was attached | subjected to the same component as the conventional hybrid integrated circuit device shown in FIG.
[0023]
First, for example, there is a metal hybrid integrated circuit board 1 punched by a press. The hybrid integrated circuit substrate 1 may be Al, Cu, Fe, or the like.
[0024]
Here, the reason why the metal substrate is used as the hybrid integrated circuit substrate is that the resin flow is punched and stopped by the burr (projection 13) when the resin is cured. However, if this flow is small, not only a metal substrate but also a ceramic substrate, a printed circuit board, or the like can be used.
[0025]
The hybrid integrated circuit board 1 is punched upward with a press from the lower side with respect to the paper surface, and the corner portion 11 around the bottom surface of the hybrid integrated circuit board 1 has a round shape.
Further, the corner portion 12 on the periphery of the upper surface of the hybrid integrated circuit board 1 is provided with a protrusion 13 over substantially the entire periphery. The side surface of the hybrid integrated circuit board 1 has a shear surface on the lower side and a fracture surface on the upper side. It is provided all around.
[0026]
When Al is adopted as the hybrid integrated circuit substrate 1, an oxide may be formed on the surface by anodic oxidation.
[0027]
In addition, since the hybrid integrated circuit board 1 has conductivity, an insulating resin 2 is applied to the entire surface in consideration of a short circuit with the conductive patterns 3 and 4 provided thereon.
[0028]
The conductive patterns 3 and 4 are made of, for example, Cu, and are provided as wirings, lands, bonding pads, fixed pads for external leads, etc., and chips (semiconductor elements) such as bare semiconductor ICs and transistors on the conductive lands. Is provided via a heat sink HS as necessary. Further, chip components 14 such as a chip capacitor, a chip resistor, and a printing resistor are provided between the wirings. These are collectively referred to as circuit elements.
[0029]
This circuit element is electrically fixed via solder, silver paste or the like, or a printing resistor is formed by screen printing or the like. Further, in order to electrically connect the semiconductor chip and the wiring, a thin metal wire 7 is electrically connected between the electrode on the chip and the bonding pad, and the fixed pad 3 for external leads is The L-shaped external lead 6 is electrically connected via solder.
[0030]
These Cu patterns may be bonded to an insulating flexible sheet, and the flexible sheet may be bonded to a hybrid integrated circuit board.
[0031]
In order to seal the hybrid integrated circuit board 1 and the circuit elements mounted thereon, a sealing resin body 20 melted from the pellet 21 which is the point of the present invention is provided.
[0032]
As shown in FIG. 2, the pellet 21 is characterized by having a shape in which one side where the external lead 6 is provided is cut out inside the hybrid integrated circuit board. The notched shape is recessed in a curved shape by about 0.5 to 3 mm at the center of the side, and the fluidity at the center of the side is weakened by utilizing the surface tension of the molten resin.
[0033]
That is, as shown in FIG. 2, the pellet 21 is arranged on the hybrid integrated circuit board 1 so that the shape corresponding to the external lead 6 is formed. Here, the pellet 21 is formed by integrating a powdery epoxy resin 23 (see FIG. 7) before thermosetting on the reinforcing sheet 22.
[0034]
The reinforcing sheet 22 needs to maintain flatness even after the resin 23 is thermally cured, and is preferably an epoxy-impregnated glass fiber or the like. A thin glass substrate or the like may also be used.
[0035]
In this state, the resin 23 is placed on, for example, a heater, melted at about 150 degrees, and then thermally cured.
[0036]
The above-described molten resin sinks due to its own weight or the weight of the reinforcing sheet, and simultaneously flows out from the end portions T1 and T2 of the reinforcing sheet to the peripheral end of the hybrid integrated circuit board 1 to form the sag portions 24 and 25.
[0037]
When the pellet 21 melts, the resin softens and flows so as to cover the entire surface of the hybrid integrated circuit board 1. Moreover, since the reinforcing sheet 22 is present on the surface, it can be cured while maintaining flatness. However, on the side where the external lead 6 having the cutout shape is provided, the surface tension that tends to spread round is weakened, and the entire side realizes a very flat fluidity. Therefore, the side where the external lead 6 is provided is prevented from flowing out to the end surface of the substrate in synergy with the effect of the protrusion 13 at the peripheral end of the substrate 1.
[0038]
FIG. 3 shows various shapes of the pellet 21. 3A and 3B are provided with shapes cut out on two sides, FIG. 3C is provided with shapes cut out on three sides, and FIG. 3D is provided with shapes cut out on four sides. This is because the density of the circuit elements is different when the circuit element is incorporated in the substrate 1, and the fluidity of the molten resin is increased at the high density side. Therefore, the pellet 21 having the shape shown in FIG.
[0039]
In the above description, the metal substrate is used as the substrate 1, but a ceramic substrate, a glass substrate, a printed substrate, a flexible substrate, or the like may be used.
[0040]
This hybrid integrated circuit device is most suitable, for example, for those requiring heat dissipation that exposes the back surface of the substrate 1.
[0041]
【The invention's effect】
According to the present invention, a resin encapsulant in which a powder resin before thermosetting is integrated and a pellet provided with a reinforcing sheet on the surface is melt-cured to seal substantially the entire area of the hybrid integrated circuit board, There is an advantage that the fluidity of the molten resin in the pellet can be controlled only by providing a cutout shape at least on the side of the pellet where the external lead is provided. As a result, an extremely inexpensive sealing structure was realized.
[0042]
Further, in the present invention, since the reinforcing sheet has flatness, printability is improved, and a model name or the like can be placed. Moreover, since it has flatness, suction can be performed by applying a suction portion of an automatic machine to the reinforcing sheet, and for example, automatic mounting can be performed on a printed circuit board or the like.
[0043]
As mentioned above, the thickness of the package can be reduced to less than half of the conventional one, the heat dissipation from the resin sealing body to the outside atmosphere can be improved, the current capacity of the semiconductor chip itself can be increased, and at the same time the label printability on the surface is also improved I was able to.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a hybrid integrated circuit device of the present invention.
FIG. 2 is a plan view of the hybrid integrated circuit device of the present invention.
FIG. 3 is a plan view for explaining the shape of a pellet used in the present invention.
FIG. 4 is a cross-sectional view illustrating a conventional general hybrid integrated circuit device.
FIG. 5 is a cross-sectional view illustrating a sealing structure of a conventional hybrid integrated circuit device.
FIG. 6 is a cross-sectional view illustrating a conventional general hybrid integrated circuit device.
FIG. 7 is a view before melting of FIG.
FIG. 8 is a plan view for explaining the spread of molten resin in pellets.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hybrid integrated circuit board 6 External lead 13 Protrusion part 20 Sealing resin body 21 Pellet 22 Reinforcing sheet

Claims (5)

A hybrid integrated circuit board provided with a conductive pattern on the surface, a circuit element electrically connected to the conductive pattern, and a pellet having a reinforcing sheet provided on the surface by integrating a powder resin before thermosetting A hybrid integrated circuit device having a resin sealing body that is cured and seals substantially the entire area of the hybrid integrated circuit substrate,
The pellet has a shape in which at least one side is notched inside the hybrid integrated circuit substrate, and a resin sealing body melted from the pellet is prevented from flowing out of the hybrid integrated circuit substrate. Hybrid integrated circuit device. 2. The hybrid integrated circuit device according to claim 1, wherein an external lead is disposed on one side of the pellet having a shape notched inside the hybrid integrated circuit substrate. 3. The hybrid integrated circuit device according to claim 1, wherein the circuit element is a semiconductor chip or a chip component fixed to the conductive pattern. 2. The hybrid integrated circuit device according to claim 1, wherein a metal substrate having an insulating surface is used as the hybrid integrated circuit substrate. The hybrid integrated circuit device according to claim 1, wherein the hybrid integrated circuit device has a plurality of sides having a shape cut out inside the hybrid integrated circuit substrate of the pellet.

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