JPH07142633A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To provide a semiconductor integrated circuit device of a structure, wherein the deformation of bonding wires and a short-circuit of wiring are prevented and moreover, a heat dissipation, a water-vaporproof reliability and a resistance to temperature cycle are improved. CONSTITUTION:A semiconductor integrated circuit device is constituted of a multilayer plastic board 2 with lead pins 1 inserted therein, a semiconductor element 3 to be mounted, a thermal diffusion plate 4 to dissipate heat generated from the element 3 and the board 2, a silicone adhesive sheet 5 to bond the plate 4 to the board 2, a silicone gel 7 to cover the periphery of the element 3 connected with the board 2 by bonding wires 6 and a cap 8 to seal the gel 7. The adhesive sheet 5 is a rolled material about 0.5mm thick, which is formed of a thermosetting resin, such as a silicone resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit device in a semiconductor manufacturing technique, and more particularly to a bonding technique for the thermal diffusion plate when the semiconductor integrated circuit device includes a thermal diffusion plate.

[0002]

2. Description of the Related Art A semiconductor integrated circuit device tends to have a large number of pins and a high power consumption as a result of higher integration and more functions. As a technique of such a semiconductor integrated circuit device that supports a large number of pins and high power consumption, a semiconductor integrated circuit device in which a thermal diffusion plate is provided in a Pin Grid Array (hereinafter, simply referred to as PGA) is used.

Now, the structure of the PGA type semiconductor integrated circuit device will be described. From a semiconductor element mounted on the multilayer plastic substrate in which lead pins, which are electrodes for transmitting signals to the outside, are inserted, and the plastic substrate. A heat diffusion plate for radiating the heat generated, an adhesive for adhering the heat diffusion plate to the plastic substrate, a silicone gel covering the periphery of the semiconductor element connected to the plastic substrate by a bonding wire, and the silicone gel. And a cap for sealing, which is adhered to the plastic substrate.

Next, the method of bonding the constituent members will be described. First, the heat diffusion plate is bonded to the plastic substrate with a liquid adhesive such as silicone, and further, the semiconductor element is bonded with a die attach agent having conductivity. To the heat diffusion plate.

After that, a general method is to seal the periphery of the bonding wire and the semiconductor element with silicone gel or the like.

[0006]

However, in the above-mentioned technique, in the step of adhering the heat diffusion plate to the plastic substrate having the lead pins, the application of the adhesive becomes insufficient (the applied adhesion The surface of the agent may become uneven).

In this state, after the semiconductor element is adhered to the heat diffusion plate with a die-attaching agent and the periphery of the semiconductor element is sealed with silicone gel or the like, the surface of the adhesive is then subjected to a temperature cycle test or the like. The silicone gel is sucked into the voids generated from the irregularities, and new voids are generated in the silicone gel.

As a result, there arises a problem that a bonding wire connecting the semiconductor element and the plastic substrate is deformed or a defect such as a wire short circuit occurs.

When applying a liquid adhesive such as silicone, the liquid adhesive has strong fluidity,
It is also a problem that it is difficult to control the coating range.

Therefore, an object of the present invention is to prevent wire deformation and wire short circuit of the bonding wire, and
It is an object of the present invention to provide a semiconductor integrated circuit device that improves heat dissipation, moisture resistance reliability and temperature cycle resistance.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0012]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

That is, a semiconductor integrated circuit device in which a semiconductor substrate is mounted by bonding a heat diffusion plate to a plastic substrate having lead pins, the plastic substrate electrically connected to the semiconductor device, and the plastic substrate. The heat-diffusing plate is adhered to the heat-diffusing plate, and the adhesive for adhering the plastic substrate and the heat-diffusing plate is used.

The sheet adhesive is a B-staged prepreg obtained by impregnating inorganic or organic fibers with a resin.

Further, the plastic substrate and the heat diffusion plate are bonded by a transfer molding method.

[0016]

According to the above-mentioned means, a sheet-like adhesive is used to bond the plastic substrate having the lead pins to the heat diffusion plate, or the plastic substrate and the heat diffusion plate are bonded to each other by the transfer molding method. By doing so, it is possible to bond the plastic substrate and the heat diffusion plate to each other without generating a void.

Therefore, in a temperature cycle test or the like, it is possible to prevent the silicone gel sealing the periphery of the semiconductor element from being sucked into the void.

As a result, voids in the silicone gel do not occur, so that deformation of the bonding wire can be prevented, and defects such as wire shorts can be prevented.

Further, by using a sheet-like adhesive as the adhesive, it is possible to control the application range,
Further, the workability can be improved because the application work is easier than the liquid adhesive.

[0020]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view showing an example of the structure of a semiconductor integrated circuit device according to an embodiment of the present invention.

The structure of the semiconductor integrated circuit device according to the first embodiment will be described with reference to FIG. 1. A multilayer plastic substrate 2 in which lead pins 1 which are electrodes for transmitting signals to the outside are inserted, and a semiconductor to be mounted. A heat diffusion plate 4 for radiating heat generated from the element 3 and the plastic substrate 2
A silicone sheet adhesive 5 for adhering the heat diffusion plate 4 to the plastic substrate 2, and a silicone gel 7 covering the periphery of the semiconductor element 3 electrically connected to the plastic substrate 2 by a bonding wire 6, And a cap 8 for sealing the silicone gel 7,
The cap 8 is adhered to the plastic substrate 2 by the silicone sheet adhesive 5.

Here, the silicone-based sheet adhesive 5 of Example 1 is equivalent to silicone having a vinyl group and silicone having hydrogensilane as a crosslinking agent, and a filler made of silicon dioxide to the silicone. 30% by weight, and 2% by weight of a silane coupling agent were mixed and roll-kneaded at room temperature to finish the thickness to about 0.5 mm.

Next, the method for adhering the constituent members of the semiconductor integrated circuit device according to the first embodiment will be described with reference to FIG. 1. First, the plastic substrate 2 and the heat diffusion plate 4 are attached to the silicone sheet adhesive 5 described above. Glued by 150 ℃
Curing takes 1 hour.

Then, after curing, the semiconductor element 3 is adhered to the heat diffusion plate 4 using the die attaching agent 9, and the bonding wire 6
After that, the semiconductor element 3 and the bonding wire 6 are sealed with the silicone gel 7 and cured at 150 ° C./1 hour.

Further, the cap 8 is adhered to the plastic substrate 2 using the above-mentioned silicone sheet adhesive 5,
Curing is performed at 150 ° C./1 hour.

As a result, the semiconductor integrated circuit device according to the first embodiment is completed.

Next, the operation of the semiconductor integrated circuit device according to the first embodiment will be described with reference to FIG. 1. Silicone sheet-like adhesive which is a sheet-like adhesive for adhering the plastic substrate 2 and the heat diffusion plate 4 together. By using the agent 5, the plastic substrate 2 and the heat diffusion plate 4 can be bonded to each other without generating a void.

As a result, the heat diffusion plate 4 comes into close contact with the plastic substrate 2, so that the heat dissipation of the heat diffusion plate 4 can be improved.

Further, in the step of attaching the cap 8 and the temperature cycle test, it is possible to prevent the silicone gel 7 for sealing the periphery of the semiconductor element 3 from being sucked into the void.

Therefore, since no voids are generated in the silicone gel 7, it is possible to prevent the deformation of the bonding wire 6, and it is also possible to prevent the occurrence of defects such as wire shorts.

As a result, it is possible to improve the moisture resistance reliability and the temperature cycle resistance, and further improve the reliability of the connection portion by wire bonding.

Further, by using the silicone sheet adhesive 5 as the adhesive, the application range can be controlled.

Furthermore, since the coating work is easier than the liquid adhesive, the workability can be improved.

(Embodiment 2) FIG. 2 is a sectional view showing an example of the structure of a semiconductor integrated circuit device according to another embodiment of the present invention.

The structure of the semiconductor integrated circuit device according to the second embodiment will be described with reference to FIG. 2. The multilayer plastic substrate 2 into which the lead pin 1 which is an electrode for transmitting a signal to the outside is inserted, and the semiconductor to be mounted. A heat diffusion plate 4 for radiating heat generated from the element 3 and the plastic substrate 2
An epoxy-phenolic sheet adhesive 10 for adhering the heat diffusion plate 4 to the plastic substrate 2, and a silicone gel 7 covering the periphery of the semiconductor element 3 electrically connected to the plastic substrate 2 by a bonding wire 6. And a cap 8 for sealing the silicone gel 7, and the cap 8 is bonded to the plastic substrate 2 by the epoxy-phenolic sheet adhesive 10.

Here, the epoxy-phenolic sheet adhesive 10 of Example 2 was prepared by dissolving an o-cresol novolac type epoxy resin and a novolac type phenolic resin in an equivalent amount each in tetrahydrofuran and dissolving them in a silane cup. A varnish was prepared by adding 1% by weight of a ring agent to the resin content, impregnated in a glass cloth having a thickness of 0.1 mm, and then the solvent was removed. It is a prepreg.

Next, in the method of bonding the constituent members of the semiconductor integrated circuit device according to the second embodiment, the silicone-based sheet adhesive 5 described in the first embodiment is simply replaced with the epoxy-phenolic sheet-like adhesive 10. The operation of the semiconductor integrated circuit device according to the second embodiment is also the same as that described in the first embodiment, and the description thereof will be omitted.

The semiconductor element 3 is adhered to the heat diffusion plate 4 by the die attaching agent 9.

(Embodiment 3) FIG. 3 is a sectional view showing an example of the structure of a semiconductor integrated circuit device according to another embodiment of the present invention.

The configuration of the semiconductor integrated circuit device according to the third embodiment will be described with reference to FIG. 3. The multilayer plastic substrate 2 into which the lead pin 1 which is an electrode for transmitting a signal to the outside is inserted, and the semiconductor to be mounted. A heat diffusion plate 4 for radiating heat generated from the element 3 and the plastic substrate 2
A transfer mold injection adhesive 11 for adhering the heat diffusion plate 4 to the plastic substrate 2, and a silicone gel 7 for covering the periphery of the semiconductor element 3 electrically connected to the plastic substrate 2 by the bonding wire 6.
And a cap 8 for encapsulating the silicone gel 7. The cap 8 is formed by the silicone sheet adhesive 5 (see Example 1).
Is glued to.

Here, the transfer mold injection system adhesive 11 of the third embodiment is press-fitted between the plastic substrate 2 and the heat diffusion plate 4 by the transfer mold system so as to bond them to each other. It is a composition in which a curing agent such as imidazole is mixed with a system resin, and a curing accelerator, a filler, a coupling agent and the like are mixed therein.

Next, as a method of adhering the constituent members of the semiconductor integrated circuit device according to the third embodiment, a transfer mold injection method adhesion in which the silicone sheet adhesive 5 described in the first embodiment is pressed by the transfer mold method. Only the agent 11 is replaced, and the operation of the semiconductor integrated circuit device according to the third embodiment is completely the same as that described in the first embodiment, and therefore the description thereof is omitted.

The semiconductor element 3 is adhered to the heat diffusion plate 4 by the die attaching agent 9.

Next, FIG. 4 shows the number of occurrences of defects in the semiconductor integrated circuit devices of Examples 1 to 3 of the present invention and Comparative Example 1 (described later) after silicone gel sealing, capping and temperature cycle test. It is a test result explanatory view which shows an example of the test data showing.

Here, the semiconductor integrated circuit device according to Comparative Example 1 will be described with reference to FIG. 1. The viscosity between the plastic substrate 2 and the heat diffusion plate 4, and between the plastic substrate 2 and the cap 8 is about 600. A two-component silicone of poise is applied by a syringe and cured, and then a semiconductor integrated circuit device is manufactured by the same procedure as in the first embodiment.

A detailed description will be given of the method of confirming the number of defective occurrences in the test result diagram of FIG. 4 (see FIG. 1 for the reference numerals of the components of the semiconductor integrated circuit device).
3 to 30 and 30 semiconductor integrated circuit devices described in Comparative Example 1 as samples, and after the silicone gel 7 of each semiconductor integrated circuit device is cured and after the adhesive with the cap 8 is cured, the wire is deformed by opening. And wire short-circuit and the presence or absence of voids in the silicone gel 7 were confirmed, and those in which wire deformation or wire short-circuit did not occur in these steps were subjected to a temperature cycle test (-55 ° C / 30 minutes, 150 ° C / 30 min. Minutes)
Is performed up to 1000 cycles to check for wire shorts and voids in the silicone gel 7.

Here, in FIG. 4, the denominator indicates the number of samples, and the numerator indicates the number of defective occurrences.

As shown in the test result diagram of FIG. 4, in Examples 1 to 3, no defect occurred, and Comparative Example 1
The defect was confirmed only in.

As a result, by using a sheet-shaped adhesive or a transfer molding type press-fitting method as an adhesive for adhering the plastic substrate 2 and the heat diffusion plate 4, wire shorts and voids in the silicone gel 7 are generated. It turned out not to.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the resins used in the sheet-like adhesives described in Examples 1 and 2 were silicone type (Example 1) and epoxy-phenol type (Example 2). The resin may be a polyimide thermosetting resin or a thermoplastic resin having a heat distortion temperature of 200 ° C. or higher.

Further, each of the above resins is used alone or 2
It may be a mixture of more than one kind of resin.

Further, as the material impregnated with the resin, in addition to the cloth made of an inorganic material such as glass described in Example 2, a cloth made of an organic material such as a high-strength fiber having a high elastic modulus may be used. .

The resin used in the transfer mold injection type adhesive described in the third embodiment is a novolac type epoxy resin, a bisphenol type epoxy resin, a biphenyl type epoxy resin or an alicyclic epoxy which is generally used for semiconductor encapsulation. A resin such as a resin may be used. Further, the curing agent to be mixed with the resin may be phenol novolac other than imidazole described in Example 3, acid anhydride, amine or the like.

Next, since the application range can be controlled by using a sheet-like adhesive as the adhesive, the plastic substrate 2 and the heat diffusion plate 4 can be adhered to each other as shown in another embodiment of FIG. Both the silicone-based sheet adhesive 5 and the liquid adhesive 12 may be used.

That is, the plastic substrate 2 and the heat diffusion plate 4
In the case of bonding with the semiconductor element 3, the silicone-based sheet adhesive 5 is used only in the vicinity of the semiconductor element 3 and the liquid adhesive 12 is used on the outer side thereof. It is possible to obtain the same action and effect as the ones.

The silicone sheet adhesive 5 shown in the other embodiment of FIG. 5 is the same as the epoxy-phenolic sheet adhesive 10 described in Embodiment 2 (see FIG. 2).
May be

[0059]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

(1). Between the plastic substrate and the heat diffusion plate, by using a sheet-like adhesive for adhering the plastic substrate and the heat diffusion plate, or by adhering the plastic substrate and the heat diffusion plate by a transfer molding method. It is possible to bond the both without generating voids.

As a result, the heat diffusion plate comes into close contact with the plastic substrate, so that the heat dissipation of the heat diffusion plate can be improved.

(2). Since the plastic substrate and the heat diffusion plate can be bonded to each other without generating a void, the silicone gel that seals the periphery of the semiconductor element is sucked into the void in the capping process or the temperature cycle test. Can be prevented.

Therefore, since no void is generated in the silicone gel, the deformation of the bonding wire can be prevented, and further, the occurrence of defects such as wire short circuit can be prevented.

As a result, it is possible to improve the humidity resistance reliability and the temperature cycle resistance, and further improve the reliability of the connection portion by wire bonding.

(3). By using a sheet-like adhesive as the adhesive for adhering the plastic substrate and the heat diffusion plate, it is possible to control the application range.

(4). By using a sheet-like adhesive as the adhesive for adhering the plastic substrate and the heat diffusion plate, the application work is easier than that of the liquid adhesive, so that the workability can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a structure of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of the structure of a semiconductor integrated circuit device which is another embodiment of the present invention.

FIG. 3 is a sectional view showing an example of the structure of a semiconductor integrated circuit device which is another embodiment of the present invention.

FIG. 4 is a test showing an example of test data showing the number of defects generated after silicone gel sealing, capping and temperature cycle test in the semiconductor integrated circuit devices of Examples 1 to 3 and Comparative Example 1 of the present invention. It is a result explanatory view.

FIG. 5 is a sectional view showing an example of the structure of a semiconductor integrated circuit device which is another embodiment of the present invention.

[Explanation of symbols]

 1 Lead Pin 2 Plastic Substrate 3 Semiconductor Element 4 Thermal Diffusion Plate 5 Silicone Sheet Adhesive 6 Bonding Wire 7 Silicone Gel 8 Cap 9 Die Attachment 10 Epoxy-Phenol Sheet Adhesive 11 Transfer Mold Injection Adhesive 12 Liquid Adhesion Agent

Front page continuation (72) Inventor Teruo Kitamura 2326 Imai, Ome-shi, Tokyo Inside Hitachi Device Development Center (72) Inventor Yasumi Tsutsumi 2326 Imai, Ome-shi, Tokyo Inside Hitachi Device Development Center (72) ) Inventor Kenji Sato 145 Nakajima, Nanae-cho, Kameda-gun, Hokkaido Inside Hitachi Hokkai Semiconductor Co., Ltd.

Claims (3)

[Claims] 1. A semiconductor integrated circuit device having a semiconductor element mounted by bonding a heat diffusion plate to a plastic substrate having lead pins, the plastic substrate electrically connected to the semiconductor element, and the plastic substrate. A semiconductor integrated circuit device, comprising: a heat diffusion plate adhered to a substrate; and an adhesive agent that adheres the plastic substrate and the heat diffusion plate, wherein the adhesive agent is a sheet-shaped adhesive agent. 2. The semiconductor integrated circuit device according to claim 1, wherein the sheet-like adhesive is a prepreg obtained by impregnating an inorganic or organic fiber with a resin and forming a B-stage. 3. A semiconductor integrated circuit device in which a heat diffusion plate is bonded to a plastic substrate having lead pins and a semiconductor element is mounted on the plastic substrate, the plastic substrate electrically connected to the semiconductor element, and the plastic substrate. A semiconductor integrated circuit characterized by comprising a heat diffusion plate adhered to a substrate and an adhesive for adhering the plastic substrate and the heat diffusion plate, and adhering the plastic substrate and the heat diffusion plate by a transfer mold method. apparatus.