JP6907697B2 - Semiconductor devices and methods for manufacturing semiconductor devices - Google Patents

Description

The present invention relates to semiconductor devices and methods for manufacturing semiconductor devices.

In recent years, power semiconductor modules have come to be widely used in power conversion devices, centering on IGBTs (Insulated Gate Bipolar Transistors). The power semiconductor module contains one or more power semiconductor chips to form a part or the whole of the conversion connection, and has a structure in which the power semiconductor chip is electrically insulated from the base plate or the cooling surface. It is a power semiconductor device.

FIG. 8 is a cross-sectional view showing the configuration of a power semiconductor module having a conventional structure. As shown in FIG. 8, the power semiconductor module includes a power semiconductor chip 1, a laminated substrate 2, a metal substrate 3, a terminal case 4, a metal terminal 5, a metal wire 6, a lid 7, and a sealing material. 8 and. The power semiconductor chip 1 is a power semiconductor chip such as an IGBT or a diode, and is mounted on a laminated substrate 2. The laminated substrate 2 is provided with a conductive plate 22 such as copper on the front surface and the back surface of an insulating substrate 21 such as a ceramic substrate. The laminated substrate 2 is solder-bonded to the metal substrate 3. The terminal case 4 is adhered to the metal substrate 3 with an adhesive 9. The terminal case 4 is made of a thermoplastic resin such as polyphenylene sulfide (PPS), and is insert-molded to fix the metal terminal 5 that takes out a signal to the outside. The metal terminal 5 is fixed on the laminated substrate 2 by soldering, penetrates the lid 7, and protrudes to the outside. The metal wire 6 electrically connects the power semiconductor chip 1 and the metal terminal 5. The lid 7 is made of the same thermoplastic resin as the terminal case 4. The sealing material 8 is filled in the terminal case 4 as a sealing resin that insulates and protects the power semiconductor chip 1 on the surface of the laminated substrate 2 and on the substrate on which the power chip is mounted. Epoxy resin is usually used for the sealing material 8. Epoxy resin has high dimensional stability, water resistance, chemical resistance, and electrical insulation, and is suitable as a sealing resin (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-16684

As described above, the terminal case 4 is connected to the metal substrate 3 with the adhesive 9, and the terminal case 4 is filled with the sealing material 8. As the sealing material 8, a thermosetting resin composition such as an epoxy resin containing an inorganic filler is widely used. As the adhesive 9, a material containing silicone rubber is usually used. As the metal substrate 3, a metal having high thermal conductivity such as aluminum (Al) is used. The coefficient of linear expansion (CTE) of each member is substantially the same for the metal substrate 3, the terminal case 4, and the sealing material 8, and the adhesive 9 has a higher value than the others. As a result, when the low-temperature and high-temperature cycles are repeated, the adhesive 9 extends more than the metal substrate 3, the terminal case 4, and the sealing material 8 at high temperatures. The sealing material 8 is made of a resin composition containing an inorganic filler in a thermosetting resin. The inorganic filler enhances the thermal conductivity of the encapsulant 8 and lowers the coefficient of thermal expansion to adjust the coefficient of linear expansion to be equivalent to that of the metal substrate 3 and the terminal case 4.

Therefore, when a reliability test (heat shock test) in which a low temperature and high temperature cycle is repeated is performed, a portion where the sealing material 8, the terminal case 4, the metal substrate 3, and the adhesive 9 come into contact with each other (the location indicated by reference numeral S in FIG. 8). ), The stretched adhesive 9 causes stress on the sealing material 8. Further, since the adhesive 9 containing silicone rubber is a difficult-to-adhere material, it is weakly adhered to the epoxy resin or the like of the sealing material 8, and the sealing material 8 is cracked (starting from the place where this stress is generated). Resin cracking) occurs.

Therefore, when the reliability test is performed on this power semiconductor module, resin cracks occur from the boundary between the terminal case 4 and the metal substrate 3 in the region S toward the laminated substrate 2. Therefore, when a test such as a high temperature and high humidity bias test (THB: Temperature / Humidity Bias) is performed in combination after the reliability test, moisture permeates into the power semiconductor module and reaches the laminated substrate 2. There is a problem that the power semiconductor module is destroyed.

The present invention provides a semiconductor device and a method for manufacturing the semiconductor device, which can prevent cracks from occurring in the encapsulant even when a low temperature and a high temperature cycle are repeated in order to solve the above-mentioned problems caused by the prior art. With the goal.

In order to solve the above-mentioned problems and achieve the object of the present invention, the semiconductor device according to the present invention has the following features. A semiconductor element is mounted on the laminated substrate. The laminated substrate is mounted on the metal substrate. The resin case is adhered to the metal substrate with an adhesive. The sealing material fills the inside of the resin case. An intermediate layer is provided between the adhesive portion between the metal substrate and the resin case and the sealing material. The linear expansion coefficient of the intermediate layer is larger than the linear expansion coefficient of the sealing material and smaller than the linear expansion coefficient of the adhesive.

Further, in the semiconductor device according to the present invention, in the above-described invention, the linear expansion coefficient of the intermediate layer is an intermediate value between the linear expansion coefficient of the sealing material and the linear expansion coefficient of the adhesive. It is a feature.

Further, the semiconductor device according to the present invention is characterized in that, in the above-described invention, the elastic modulus of the intermediate layer is smaller than the elastic modulus of the encapsulant and larger than the elastic modulus of the adhesive.

Further, the semiconductor device according to the present invention is characterized in that, in the above-described invention, the elastic modulus of the intermediate layer is an intermediate value between the elastic modulus of the sealing material and the elastic modulus of the adhesive. ..

The semiconductor device according to the present invention, in the invention described above, the intermediate layer, the linear expansion coefficient in the thermosetting resin is blended with added particles of ^{20 × 10 -6 / K~400 × 10} -6 / K It is characterized by being a thing.

Further, in the semiconductor device according to the present invention, in the above-described invention, the thermosetting resin is an epoxy resin, a phenol resin, or a maleimide resin, and the added particles are silicone rubber, butadiene rubber, or acrylonitrile butadiene rubber. It is characterized by that.

Further, the semiconductor device according to the present invention is characterized in that, in the above-described invention, the added particles are contained in an amount of 1 to 10 parts by mass with respect to 100 parts by mass of the thermosetting resin.

Further, in the semiconductor device according to the present invention, in the above-described invention, the thermosetting resin as the sealing material is an epoxy resin, a phenol resin, or a maleimide resin, and the adhesive material is silicone rubber or butadiene rubber. , Or an acrylonitrile butadiene rubber.

In order to solve the above-mentioned problems and achieve the object of the present invention, the method for manufacturing a semiconductor device according to the present invention has the following features. First, the first step of mounting the semiconductor element on the laminated substrate is performed. Next, a second step of mounting the laminated substrate on the metal substrate is performed. Next, a third step of adhering the metal substrate to the resin case with an adhesive is performed. Next, a fourth step of forming an intermediate layer inside the resin case at the bonding portion between the metal substrate and the resin case is performed. Next, a fifth step of filling the inside of the resin case with a sealing material is performed. In the fourth step, the intermediate layer is formed between the adhesive portion and the sealing material so that the linear expansion coefficient is larger than the linear expansion coefficient of the sealing material and smaller than the linear expansion coefficient of the adhesive. ..

According to the invention described above, in the power semiconductor module, an intermediate layer is provided between the bonding portion between the metal substrate and the terminal case and the sealing material. The coefficient of linear expansion of the intermediate layer is about intermediate between the coefficient of linear expansion of the sealing material and the coefficient of linear expansion of the adhesive. As a result, the intermediate layer can relieve the stress generated by the elongation of the adhesive at high temperature. Therefore, it is possible to prevent cracks from occurring in the sealing material.

According to the semiconductor device and the method for manufacturing the semiconductor device according to the present invention, it is possible to prevent cracks from occurring in the encapsulant even when the low temperature and high temperature cycles are repeated, and it is possible to provide a highly reliable power semiconductor module. It works.

It is sectional drawing which shows the structure of the power semiconductor module which concerns on embodiment. It is a table which shows the coefficient of linear expansion and elastic modulus of each material of the power semiconductor module which concerns on embodiment. It is sectional drawing which shows the state in the manufacturing process of the power semiconductor module which concerns on embodiment (the 1). It is sectional drawing which shows the state in the manufacturing process of the power semiconductor module which concerns on embodiment (the 2). It is sectional drawing which shows the state in the manufacturing process of the power semiconductor module which concerns on embodiment (the 3). It is a top view which shows the state in the manufacturing process of the power semiconductor module which concerns on embodiment. It is sectional drawing which shows the state in the manufacturing process of the power semiconductor module which concerns on embodiment (the 4). It is a table which shows the evaluation result of the power semiconductor module which concerns on embodiment. It is sectional drawing which shows the structure of the power semiconductor module of a conventional structure.

Hereinafter, preferred embodiments of the semiconductor device and the method for manufacturing the semiconductor device according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a configuration of a power semiconductor module according to an embodiment.

(Embodiment)
As shown in FIG. 1, the power semiconductor module includes a power semiconductor chip 1, a laminated substrate 2, a metal substrate 3, a terminal case 4, a metal terminal 5, a metal wire 6, a lid 7, and a sealing material. 8 and an intermediate layer 10 are provided.

The power semiconductor chip 1 is a semiconductor element such as an IGBT or a diode chip. A conductive plate 22 made of a copper (Cu) plate or the like is provided on the front surface (power semiconductor chip 1 side) and the back surface (metal substrate 3 side) of an insulating substrate 21 such as a ceramic substrate that ensures insulation. Has been done. The laminated substrate 2 is a substrate provided with a conductive plate 22 on at least one surface of the insulating substrate 21. The power semiconductor chip 1 is bonded to the conductive plate 22 by a bonding material such as solder. The metal substrate 3 is bonded to the conductive plate 22 on the back surface by a bonding material such as solder. The metal substrate 3 is a heat-dissipating cooling body made of aluminum (Al) or copper (Cu).

Further, one end of a metal wire 6 is joined to the upper surface of the power semiconductor chip 1 (the surface opposite to the surface in contact with the conductive plate 22) as wiring for electrical connection. The other end of the metal wire 6 is joined to the conductive plate 22 to which the metal terminal 5 is fixed. In FIG. 1, the power semiconductor chip 1 and the conductive plate 22 are connected by using the metal wire 6, but the power semiconductor chip 1 and the conductive plate 22 may be connected by using a lead frame.

The terminal case 4 is adhered to the metal substrate 3 with an adhesive 9. The terminal case 4 is a case made of a thermoplastic resin such as PPS (polyphenylene sulfide), and the adhesive 9 is made of a material containing silicone rubber. Since the epoxy-based adhesive is too hard and there is no room for joining the terminal case 4 and the metal substrate 3, softer silicone rubber or the like is used. In addition, the sealing material 8 is filled in the terminal case 4. A lid 7 is provided to protect the sealing material 8.

As the sealing material 8, a thermosetting resin composition such as an epoxy resin containing an inorganic filler is used. More specifically, it contains a thermosetting resin, a curing agent, and an inorganic filler. Examples of the thermosetting resin used in the present embodiment include epoxy resin, phenol resin, maleimide resin and the like. The curing agent used in the present embodiment is not particularly limited as long as it can react with a thermosetting resin and can be cured, but it is preferable to use an acid anhydride-based curing agent. Examples of the inorganic filler used in this embodiment include fused silica (SiO ₂ ), silica, alumina (Al ₂ O ₃ ), aluminum hydroxide (Al (OH) ₃ ), titania (TIO ₂ ), and zirconia. (ZrO ₂ ), aluminum hydroxide (AlN), talc, clay, mica, glass fiber and the like, but are not limited thereto. The amount of the inorganic filler added is preferably 100 to 600 parts by mass when the total mass of the thermosetting resin and the curing agent is 100 parts by mass.

The intermediate layer 10 is provided between the portion where the metal substrate 3 and the terminal case 4 are adhered by the adhesive 9 and the sealing material 8. Specifically, an intermediate layer 10 is provided at a corner on the lower side (metal substrate 3 side) of the terminal case 4. Here, the corner portion is a portion where the terminal case 4 and the metal substrate 3 are adhered to each other. The width d1 of the intermediate layer 10 in the horizontal direction (direction parallel to the laminated substrate 2) is 1 mm, and the width d2 in the vertical direction (direction parallel to the metal terminal 5) is 1 mm. The width d1 in the horizontal direction and the width d2 in the vertical direction of the intermediate layer 10 are both about 1 mm, which are smaller than the width of the terminal case 4 in the vertical direction of about 4 cm and the width in the horizontal direction of about 10 cm. Therefore, the adhesion between the sealing material 8 and the terminal case 4 and the like due to the provision of the intermediate layer 10 is the same as in the conventional case.

The intermediate layer 10 is a layer that relieves stress on the sealing material 8 due to the adhesive 9. Therefore, the linear expansion coefficient of the intermediate layer 10 is larger than the linear expansion coefficient of the sealing material 8 and smaller than the linear expansion coefficient of the adhesive 9. Preferably, the coefficient of linear expansion of the intermediate layer 10 is about an intermediate value between the coefficient of linear expansion of the sealing material 8 and the coefficient of linear expansion of the adhesive 9.

Further, the elastic modulus of each member is substantially the same for the terminal case 4 and the sealing material 8 as in the linear expansion coefficient, and the adhesive 9 has a smaller value than the others. Therefore, it is preferable that the elastic modulus of the intermediate layer 10 is smaller than the elastic modulus of the sealing material 8 and larger than the elastic modulus of the adhesive 9. Further, the elastic modulus of the intermediate layer 10 is more preferably a value intermediate between the elastic modulus of the sealing material 8 and the elastic modulus of the adhesive 9. Since the value of the linear expansion coefficient is more effective in relaxing the stress, the linear expansion coefficient of the intermediate layer 10 is between the linear expansion coefficient of the sealing material 8 and the linear expansion coefficient of the adhesive 9. When the value is about the same, the elastic modulus of the intermediate layer 10 does not necessarily have to be an intermediate value between the elastic modulus of the sealing material 8 and the elastic modulus of the adhesive 9.

Here, FIG. 2 is a table showing the coefficient of linear expansion and the elastic modulus of each material of the power semiconductor module according to the embodiment. PPS is a material used for the terminal case 4, epoxy resin is a material used for the sealing material 8, Al is a material used for the metal substrate 3, and silicone is a material used for the adhesive 9. .. The value of the epoxy resin here is a value when silicon oxide is added as an inorganic filler to the epoxy resin as a thermosetting resin because it is used as the sealing material 8, and is the value of the epoxy resin alone. Is different. With the epoxy resin alone, the coefficient of linear expansion is ^{about 50 × 10 -6} / K.

From this table, since the coefficient of linear expansion (CTE) of the epoxy resin is 16 × 10 ^-6 / K and the coefficient of linear expansion of silicone is 300 × 10 ^-6 / K, the coefficient of linear expansion of the intermediate layer 10 is 20 ×. It is preferably ^{10 -6} / K to 200 × 10 ^{-6 / K. Further, 100 × 10 -6} / K to 150 × 10 ^-6 / K, which is an intermediate level between the sealing material and the adhesive, is preferable. Similarly, the elastic modulus of the intermediate layer 10 is preferably 3 GPa to 10 GPa. Further, 5 GPa to 7 GPa, which is between the sealing resin and the adhesive, is preferable.

The intermediate layer 10 is formed by dispersing added particles having a low elastic modulus and a high linear expansion coefficient in a resin composition containing a thermosetting resin such as an epoxy resin. The resin composition of the intermediate layer 10 contains a thermosetting resin and a curing agent. For example, setting the linear expansion coefficient of the intermediate layer 10 to the above-mentioned value means that particles added to a resin composition containing a thermosetting resin such as an epoxy resin, a phenol resin, or a maleimide resin have a low elastic modulus and a high linear expansion coefficient. This can be achieved by combining materials (for example, silicone rubber).

Further, the intermediate layer 10 can be realized by dispersing added particles having a low elastic modulus and a high linear expansion coefficient in a resin composition containing a thermosetting resin used for the sealing material 8. That is, it can also be realized by using a resin of the same type as the thermosetting resin of the sealing material 8 as the thermosetting resin of the intermediate layer 10. Specifically, when the thermosetting resin of the sealing material 8 is an epoxy resin, the intermediate layer 10 is formed by blending additive particles (for example, silicone rubber particles) with the epoxy resin.

It can also be realized by forming the intermediate layer 10 on the thermosetting resin used for the sealing material 8 by using the material used for the adhesive material 9 as additive particles. The intermediate layer 10 needs to have a coefficient of linear expansion larger than the coefficient of linear expansion of the sealing material 8 and smaller than the coefficient of linear expansion of the adhesive 9. For this purpose, the linear expansion coefficient of the additive particles is preferably ^{20 × 10 -6 / K~400 × 10} -6 / K, and more preferably ^{200 × 10 -6 / K~300 × 10} -6 / K. The elastic modulus is also preferably 1 GPa to 10 GPa, more preferably 1 GPa to 4 GPa. This is because the compounding ratio of the added particles can be reduced within this range. If more particles such as silicone rubber are added than a predetermined amount, the strength of the resin composition decreases, so it is desirable that the compounding ratio is small.

In addition to the silicone rubber, the added particles may be other added particles having the same linear expansion coefficient value, such as butadiene rubber and acrylonitrile butadiene rubber. The average particle size of the added particles is preferably 2 μm to 20 μm. This is because, in this range, the physical property values such as the coefficient of linear expansion of the dispersed intermediate layer 10 tend to be uniform. If it is too fine, the intermediate layer 10 does not reflect the physical properties of the added particles. On the other hand, if it is too large, the physical property values such as the coefficient of linear expansion will be locally different, and the variation will be large.

Further, the thermosetting resin may be another resin having a coefficient of linear expansion similar to that of the epoxy resin, for example, a phenol resin, a maleimide resin, or the like. Silicone rubber or the like is a material that exhibits an elastomer having rubber elasticity at room temperature and exhibits a small elastic modulus of about 1 MPa to 10 MPa.

The blending ratio of the added particles such as silicone rubber particles will be described in detail in Examples described later, but 1 to 10 mass by mass with respect to 100 parts by mass of the epoxy resin (thermosetting resin) in the encapsulant 8. It is preferable that the portion is included. Further, when additive particles other than silicone rubber and resins other than epoxy resin are used, the same compounding ratio is preferable. By setting the compounding ratio as described above, the linear expansion coefficient and elastic modulus of the intermediate layer 10 can be set to about an intermediate level between the linear expansion coefficient and elastic modulus of the sealing material 8 and the adhesive 9. Further, it is not necessary to put an inorganic filler in the resin composition of the intermediate layer 10. This is because the intermediate layer 10 is provided at the corner of the resin case 4 and is separated from the power semiconductor chip 1, so that thermal conductivity is not required.

Next, a method of manufacturing the power semiconductor module according to the embodiment will be described. 3 to 5A and 6 are cross-sectional views showing a state in the middle of manufacturing the power semiconductor module according to the embodiment. First, the power semiconductor chip 1 is mounted on the laminated substrate 2 by joining the power semiconductor chip 1 to the laminated substrate 2 using a bonding material such as solder. Next, the power semiconductor chip 1 and the conductive plate 22 provided on the laminated substrate 2 are electrically connected by the metal wire 6. Next, the metal terminal 5 is attached to the conductive plate 22 to which the metal wire 6 is connected. Next, using a joining material such as solder, these are joined to the metal substrate 3 to assemble a laminated assembly composed of a power semiconductor chip 1, a laminated substrate 2, and a metal substrate 3. Further, instead of the metal wire 6, a metal terminal may be joined. The state up to this point is shown in FIG.

Next, the resin case 4 is adhered to the laminated assembly with an adhesive 9 such as a silicone adhesive. Specifically, a silicone adhesive manufactured by Momentive Co., Ltd. and having a trade name of "TSE3941" is used. The state up to this point is shown in FIG. Next, a material to be an intermediate layer 10 is applied to the inside of the terminal case 4 at the portion where the metal substrate 3 and the terminal case 4 are adhered, for example, a mixture of epoxy resin and silicone rubber. Next, the intermediate layer 10 will be described.

Bisphenol A type epoxy resin (manufactured by Nippon Steel & Sumitomo Metal Corporation, trade name "YD-825GS") and aminoglycidyl ether type epoxy resin (Japan Epoxy Resin Co., Ltd., trade name EP-630) are equal in mass as thermosetting resin main agents. The mixture used in was used. Then, 1 to 10 parts by mass of powdered silicone rubber was mixed with the thermosetting resin with respect to 100 parts by mass of the thermosetting resin. The silicone rubber was used as a powder having an average particle size of 4.5 μm. Further, as the curing agent, 120 parts by mass of acid anhydride was used with respect to 100 parts by mass of the thermosetting resin main agent.

FIG. 5B is a top view showing a state in the middle of manufacturing the power semiconductor module according to the embodiment. As shown in FIG. 5B, the material to be the intermediate layer 10 is applied to the inner corner portion of the terminal case 4, and the intermediate layer 10 is formed at this portion. After that, heat treatment is performed to cure the intermediate layer 10. The temperature and time of the heat treatment may be the same values as the temperature and time of the heat treatment when the sealing material 8 is cured. Further, since the intermediate layer 10 and the sealing material 8 do not mix with each other, the heat treatment here may be omitted and the sealing material 8 may be cured by the heat treatment for curing to form the intermediate layer 10. .. The states up to this point are shown in FIGS. 5A and 5B.

Next, the resin case 4 is filled with a sealing material 8 such as a hard resin such as an epoxy resin. The sealing material 8 will be described. Bisphenol A type epoxy resin (manufactured by Nippon Steel & Sumitomo Metal Corporation, trade name "YD-825GS") and aminoglycidyl ether type epoxy resin (Japan Epoxy Resin Co., Ltd., trade name EP-630) are used as thermosetting resins in equal mass. A mixture was used. Further, as the curing agent, 120 parts by mass of acid anhydride was used with respect to 100 parts by mass of the thermosetting resin main agent. Further, as the inorganic filler, molten silica particles having an average particle size of 5 μm (manufactured by Takimori Co., Ltd., trade name “ZA-30”) were used. The amount added was adjusted to 230 parts by mass when the total mass of the thermosetting resin main agent and the curing agent was 100 parts by mass. These were mixed to obtain an uncured resin composition. After that, it is heated and cured under the conditions of 100 ° C. for 1 hour and 200 ° C. for 1 hour. Next, a lid 7 is attached to prevent the sealing material 8 from leaking to the outside. The state up to this point is shown in FIG. As described above, the power semiconductor module according to the embodiment of the present invention can be manufactured.

(Example)
FIG. 7 is a table showing the evaluation results of the power semiconductor module according to the embodiment. The power semiconductor module according to the embodiment is prepared under various conditions, and the result of performing a heat shock test on the prepared power semiconductor module is shown. In the heat shock test, the temperature was changed from −40 ° C. to 125 ° C. 1000 times.

In FIGS. 7 and 7, in Examples 1 to 3, the intermediate layer 10 is a mixture of epoxy resin and silicone rubber, and the ratios of the silicone rubber to the total amount of the epoxy resin are 1 wt%, 5 wt%, and 10 wt%, respectively. The silicone rubber was manufactured by Dow Corning Co., Ltd. under the trade name "SH52U" and used as a powder having an average particle size of 4.5 μm. Further, in Example 4, the intermediate layer 10 is a mixture of epoxy resin and butadiene rubber, and the ratio of butadiene rubber to the total amount of epoxy resin is 5 wt%. As the butadiene rubber, Nippon Zeon Corporation, trade name "Nipol BR1220" was used as a powder having an average particle size of 4.5 μm. Further, in Example 5, the intermediate layer 10 is a mixture of an epoxy resin and acrylonitrile butadiene rubber, and the ratio of the acrylonitrile butadiene rubber to the total amount of the epoxy resin is 5 wt%. As the acrylonitrile butadiene rubber, Zeon Corporation's trade name "Nipol DN003" was used as a powder having an average particle size of 4.5 μm. In Examples 1 to 5, the film thickness of the intermediate layer 10 (width d1 in the horizontal direction and width d2 in the vertical direction) is all 1 mm. Further, the comparative example is an example of a conventional power semiconductor module in which the intermediate layer 10 is not provided.

As shown in FIG. 7, in all of Examples 1 to 5, no cracks were generated in the sealing material 8 after the heat shock test. On the other hand, in the comparative example, cracks were generated in the sealing material 8 during the heat shock test. As a result, it was found that the intermediate layer 10 of the present invention relaxes the stress and prevents cracks from being generated in the sealing material 8. Further, since cracks do not occur in all of Examples 1 to 5, cracks are generated in the sealing material 8 in any case where the epoxy resin is mixed with silicone rubber, butadiene rubber, or acrylonitrile butadiene rubber as the intermediate layer 10. It was found that it can be prevented from occurring. Further, it was found that since cracks do not occur in all of Examples 1 to 3, it is possible to prevent cracks from occurring in the sealing material 8 when the addition amount of the silicone rubber is 1 wt% to 10 wt%. Even in the case of butadiene rubber and acrylonitrile butadiene rubber, it was confirmed that cracks could be prevented from occurring in the sealing material 8 with an addition amount of 1 wt% to 10 wt%.

As described above, according to the power semiconductor module according to the embodiment, an intermediate layer is provided between the adhesive portion between the metal substrate and the terminal case and the sealing material. The coefficient of linear expansion of the intermediate layer is about intermediate between the coefficient of linear expansion of the sealing material and the coefficient of linear expansion of the adhesive. As a result, the intermediate layer can relieve the stress generated by the elongation of the adhesive at high temperature. Therefore, it is possible to prevent cracks from occurring in the sealing material, and it is possible to provide a highly reliable power semiconductor module.

As described above, the semiconductor device and the method for manufacturing the semiconductor device according to the present invention are useful for power conversion devices such as inverters, power supply devices for various industrial machines, and power semiconductor devices used for igniters of automobiles. be.

1 Power semiconductor chip 2 Laminated board 21 Insulating board 22 Conductive board 3 Metal board 4 Terminal case 5 Metal terminal 6 Metal wire 7 Lid 8 Encapsulant 9 Adhesive 10 Intermediate layer

Claims (9)

Laminated substrate with semiconductor elements and
A metal substrate on which the laminated substrate is mounted and
A resin case in which the metal substrate is adhered with an adhesive,
With the sealing material filled in the resin case,
An intermediate layer provided between the adhesive portion between the metal substrate and the resin case and the sealing material,
With
The semiconductor device is characterized in that the linear expansion coefficient of the intermediate layer is larger than the linear expansion coefficient of the sealing material and smaller than the linear expansion coefficient of the adhesive. The semiconductor device according to claim 1, wherein the intermediate layer has a coefficient of linear expansion intermediate between the coefficient of linear expansion of the sealing material and the coefficient of linear expansion of the adhesive. The semiconductor device according to claim 1 or 2, wherein the intermediate layer has an elastic modulus smaller than the elastic modulus of the sealing material and larger than the elastic modulus of the adhesive. The semiconductor device according to claim 1 or 2, wherein the intermediate layer has an elastic modulus intermediate between the elastic modulus of the sealing material and the elastic modulus of the adhesive. The intermediate layer, any of claims 1 to 4, characterized in that the linear expansion coefficient of the thermosetting resin is obtained by blending the additive particles of ^{20 × 10 -6 / K~400 × 10} -6 / K The semiconductor device described in one. The semiconductor device according to claim 5, wherein the thermosetting resin is an epoxy resin, a phenol resin, or a maleimide resin, and the added particles are a silicone rubber, a butadiene rubber, or an acrylonitrile butadiene rubber. The semiconductor device according to claim 5 or 6, wherein the added particles are contained in an amount of 1 to 10 parts by mass with respect to 100 parts by mass of the thermosetting resin. 5. The thermosetting resin as the sealing material is an epoxy resin, a phenol resin, or a maleimide resin, and the material of the adhesive is silicone rubber, butadiene rubber, or acrylonitrile butadiene rubber. Or the semiconductor device according to 6. The first step of mounting a semiconductor element on a laminated substrate and
The second step of mounting the laminated substrate on the metal substrate and
The third step of adhering the metal substrate to the resin case with an adhesive, and
A fourth step of forming an intermediate layer inside the resin case at the bonding portion between the metal substrate and the resin case, and
The fifth step of filling the inside of the resin case with a sealing material and
Including
In the fourth step, the intermediate layer is formed between the adhesive portion and the sealing material so that the linear expansion coefficient is larger than the linear expansion coefficient of the sealing material and smaller than the linear expansion coefficient of the adhesive. A method for manufacturing a semiconductor device.

Images