Semiconductor module and method for manufacturing the same

Abstract

To provide a semiconductor module and a method for manufacturing the semiconductor module with higher withstand voltage and reliability by reducing the decrease in adhesion between components due to moisture absorption of encapsulating resin, etc.SOLUTION: A semiconductor module has a laminate substrate 5 on which the semiconductor device 1 is mounted, a metal substrate 26 on which the laminate substrate 5 is mounted, a case 7 to which the metal substrate 26 is bonded with adhesive, a first sealing resin 8 filling the case, and a protective substrate 31 positioned above the first sealing resin 8. The protective substrate 31 is a ceramic substrate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a semiconductor module and a method for manufacturing the semiconductor module. [Background technology]

[0002] A power semiconductor module is a power semiconductor device that incorporates one or more power semiconductor chips to form a part or the whole of a conversion connection, and has a structure in which the power semiconductor chip is electrically insulated from a laminated substrate having a conductive plate for wiring, and from a metal substrate that is a heat sink. Power semiconductor modules are used in industrial applications such as motor drive control inverters for elevators, etc. In recent years, they have also become widely used in vehicle motor drive control inverters. Vehicle inverters are required to be small and lightweight to improve fuel efficiency, and long-term reliability at high temperatures is required because they are placed near the drive motor in the engine room.

[0003] Here, in-vehicle power semiconductor modules are required to be smaller and lighter than industrial power semiconductor modules due to the constraints of installation space. In addition, as the output power density for driving the motor increases, the temperature of the semiconductor chip during operation increases, and high thermal stress occurs, so the demand for long-term reliability during high-temperature operation is also increasing. For this reason, there is a demand for a power semiconductor module structure that can operate at high temperatures and has long-term reliability.

[0004] A semiconductor module is known in which a soft coating resin layer such as polyimide is provided as a stress relief layer on the surfaces of semiconductor element chips, wiring components such as wires, and laminated substrates, and then a hard sealing resin such as epoxy resin is filled on top of that (see Patent Document 1).

[0005] FIG. 9 is a cross-sectional view showing the configuration of a power semiconductor module having a conventional structure. As shown in FIG. 9, a power semiconductor module 150 includes a power semiconductor chip 101, an insulating substrate 102, a case 107, a heat dissipation base 126, a metal terminal 109, and a metal wire 110. The power semiconductor chip 101 is a power semiconductor chip such as an IGBT or a diode, and is bonded to the insulating substrate 102 with a bonding layer 125 such as solder. A laminated substrate 105 is a substrate in which a first conductive plate 103 such as copper is provided on the front surface of an insulating substrate 102 such as a ceramic substrate, and a second conductive plate 104 such as copper is provided on the back surface. The laminated substrate 105 is bonded to the heat dissipation base 126 with a bonding layer 125 such as solder. A metal terminal 109 for extracting a signal to the outside is bonded to the case 107. The metal wire 110 electrically connects the power semiconductor chip 101 and the metal terminal 109. Although not shown, a plurality of these members are mounted on one semiconductor device. A case 107 is bonded to the power semiconductor module 150, and a lid (not shown) is attached, through which metal terminals 109 penetrate and protrude to the outside. A primer layer 130 is provided on the creeping surface of the laminated substrate 105 and on the surface of the power semiconductor chip 101 on the substrate, and the case 107 is filled with sealing resin 108 that insulates and protects them. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-32617 A Summary of the Invention [Problem to be solved by the invention]

[0007] As with conventional structures, resin-sealed modules are becoming more common in recent power semiconductor modules to ensure reliability. In resin-sealed modules, it is important to ensure adhesion between the resin used for sealing and the module components (sealed components such as semiconductor chips and wiring components such as conductive plates) and to prevent peeling, which can cause insulation failure.

[0008] In particular, for on-board electrical modules that require high reliability, a primer layer 130 made of polyamide or polyamideimide that improves the adhesion between the epoxy sealing resin and the module components is applied to the module components such as the insulating substrate 102 and the power semiconductor chip 101 to prevent peeling.

[0009] However, one of the causes of the deterioration of the reliability of a semiconductor module is a shortened lifespan (reduced P / C tolerance) due to moisture absorption from the outside. FIG. 10 is an enlarged cross-sectional view of a portion A in FIG. 9 of a power semiconductor module 150 having a conventional structure when absorbing moisture. Since the primer layer 130 has a property of decreasing adhesion when it is given moisture, it is considered that peeling 132 occurs at the interface between the primer layer 130 and the module member (the first conductive plate 103 in FIG. 10) due to moisture absorption, and the tolerance of the power semiconductor module 150 decreases. Even if the primer layer 130 is not present, the sealing resin 108 itself may deteriorate due to long-term heat stress or moisture absorption, or the adhesion of the interface between the sealing resin 108 and the module member may decrease, causing peeling. In such a case, gas such as oxygen or sulfur may enter from the outside, causing the module member to deteriorate, and the tolerance of the power semiconductor module 150 may decrease.

[0010] In order to solve the problems associated with the prior art described above, an object of the present invention is to provide a semiconductor module and a method for manufacturing a semiconductor module that reduce the decrease in adhesion between components due to moisture absorption by the sealing resin and have higher durability and reliability. [Means for solving the problem]

[0011] In order to solve the above problems and achieve the object of the present invention, the semiconductor module according to the present invention has the following features: The semiconductor module includes a laminated substrate on which a semiconductor element is mounted, a metal substrate on which the laminated substrate is mounted, a case in which the metal substrate is bonded with an adhesive, a first sealing resin filling the inside of the case, and a protection substrate disposed on the first sealing resin. a second sealing resin between the first sealing resin and the protection substrate; Equipped with. The linear expansion coefficient α of the first sealing resin 1 and the linear expansion coefficient α of the protective substrate p and the linear expansion coefficient α of the second sealing resin 2 is α 1 >α 2 >α p In order to solve the above-mentioned problems and achieve the object of the present invention, the semiconductor module according to the present invention has the following features. The semiconductor module includes a laminated substrate on which a semiconductor element is mounted, a metal substrate on which the laminated substrate is mounted, a case to which the metal substrate is bonded with an adhesive, a first sealing resin that fills the inside of the case, and a protective substrate that is disposed on top of the first sealing resin. A primer layer made of a resin containing polyamide, polyimide, or polyamideimide is applied to the surfaces of the semiconductor element, the laminated substrate, and the case.

[0012] In the semiconductor module according to the present invention, in the above-mentioned invention, the protection substrate is a ceramic substrate.

[0014] In addition, in the semiconductor module according to the present invention, a linear expansion coefficient α1 of the first sealing resin and a linear expansion coefficient α of the protection substrate are p The difference is 10 x 10 -6 / °C.

[0016] In addition, in the semiconductor module according to the present invention, a linear expansion coefficient α2 of the second sealing resin and a linear expansion coefficient α of the protection substrate are p The difference is 10 x 10 -6 / °C.

[0018] In order to solve the above-mentioned problems and achieve the object of the present invention, the method for manufacturing a semiconductor module according to the present invention has the following features. First, a first step is performed in which a semiconductor element is mounted on a laminated substrate. Next, a second step is performed in which the laminated substrate is mounted on a metal substrate. Next, a third step is performed in which the metal substrate is bonded to a case with an adhesive. Next, a fourth step is performed in which the inside of the case is filled with a first sealing resin. Next, a fifth step is performed in which a protective substrate is disposed on top of the first sealing resin. The method further includes a sixth step of providing a second sealing resin on the first sealing resin after the fourth step and before the fifth step, and in the fifth step, the protection substrate is disposed on the second sealing resin, and the linear expansion coefficient α of the first sealing resin is 1 and the linear expansion coefficient α of the protective substrate p and the linear expansion coefficient α of the second sealing resin 2 is α 1 >α 2 >α p Meet the following.

[0019] In order to solve the above-mentioned problems and achieve the object of the present invention, the manufacturing method of a semiconductor module according to the present invention has the following features. First, a first step is performed in which a semiconductor element is mounted on a laminated substrate. Next, a second step is performed in which the laminated substrate is mounted on a metal substrate. Next, a third step is performed in which the metal substrate is bonded to a case with an adhesive. Next, a fourth step is performed in which the inside of the case is filled with a first sealing resin. Next, a fifth step is performed in which a protective substrate is disposed on top of the first sealing resin. In the fifth step, the first sealing resin is provisionally cured, the protective substrate is disposed on the upper surface of the first sealing resin, and the first sealing resin is fully cured.

[0020] In order to solve the above-mentioned problems and achieve the object of the present invention, the method for manufacturing a semiconductor module according to the present invention has the following features. First, a first step is performed in which a semiconductor element is mounted on a laminated substrate. Next, a second step is performed in which the laminated substrate is mounted on a metal substrate. Next, a third step is performed in which the metal substrate is attached to a case with an adhesive. Next, a fourth step is performed in which the inside of the case is filled with a first sealing resin. Next, a fifth step is performed in which a protective substrate is disposed on top of the first sealing resin. After the fourth step and before the fifth step, the method further includes a sixth step of providing a second sealing resin on top of the first sealing resin, and in the fifth step, the second sealing resin is provisionally cured, the protective substrate is disposed on the upper surface of the second sealing resin, and the second sealing resin is fully cured.

[0022] According to the above-mentioned invention, by disposing a protective substrate on the upper surface of the first sealing resin, moisture-proofing performance is improved, and peeling that causes a decrease in adhesion between the primer layer and the module components and insulation failure due to deterioration of the sealing resin itself is suppressed, resulting in a more reliable power semiconductor module.

[0023] In addition, a second sealing resin is disposed between the first sealing resin and the protective substrate. This reduces the difference in linear expansion coefficient between the first sealing resin, the second sealing resin, and the protective substrate, and reduces thermal stress caused by the difference in linear expansion coefficient. Therefore, even if a sudden temperature change occurs, peeling can be prevented at the interface between the first sealing resin and the second sealing resin and the interface between the second sealing resin and the protective substrate, and the reliability of the power semiconductor module can be further improved. Effect of the Invention

[0024] The semiconductor module and the method for manufacturing the semiconductor module according to the present invention have the effect of reducing the decrease in adhesion between members due to moisture absorption by the sealing resin, etc., and achieving higher durability and higher reliability. [Brief description of the drawings]

[0025] [Figure 1] 1 is a cross-sectional view showing a configuration of a power semiconductor module according to a first embodiment. [Diagram 2] 2 is an enlarged cross-sectional view of a portion A of FIG. 1 when the power semiconductor module according to the first embodiment absorbs moisture. [Diagram 3] 6 is a cross-sectional view showing another structure of the protection substrate and the sealing resin of the power semiconductor module according to the first embodiment. FIG. [Figure 4] FIG. 11 is a cross-sectional view showing details of the periphery of a protection substrate of a power semiconductor module according to a second embodiment. [Diagram 5] 1 is a table showing the properties (water absorption rate, linear expansion coefficient) of each layer of the first sealing resin, the second sealing resin, and the protective substrate structure of Examples and Comparative Examples. [Figure 6]1 is a table showing the materials and their properties used in forming a first sealing resin, a second sealing resin, and a protective substrate in Examples and Comparative Examples. [Figure 7A] 1 is a table showing evaluation results mainly for examples and comparative examples of the first embodiment. [Figure 7B] 13 is a table showing evaluation results of examples and comparative examples of the second embodiment. [Figure 8] FIG. 2 is a cross-sectional view showing details of the periphery of the protective substrates of Examples 4 to 13. [Figure 9] FIG. 1 is a cross-sectional view showing a configuration of a power semiconductor module having a conventional structure. [Figure 10] 10 is an enlarged cross-sectional view of a portion A of FIG. 9 when the power semiconductor module of the conventional structure absorbs moisture. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method for manufacturing a semiconductor device according to the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

[0027] (Embodiment 1) FIG. 1 is a cross-sectional view showing the configuration of a power semiconductor module according to the first embodiment. In the power semiconductor module 50, a first conductive plate 3 made of copper or the like is arranged on one surface of an insulating substrate 2, and a second conductive plate 4 made of copper or the like is arranged on the other surface, that is, the back surface, to form a laminated substrate 5. A plurality of power semiconductor chips 1 are mounted on the front surface of the first conductive plate 3 of the laminated substrate 5 via a bonding layer 25 made of solder or the like. A metal terminal 9 for extracting a signal to the outside is bonded to the inside of the case 7. Furthermore, a metal wire 10 made of aluminum wire or the like is attached to the front surface of the power semiconductor chip 1 via the bonding layer 25, and electrically connects the power semiconductor chip 1 and the metal terminal 9. A lead frame may be used (not shown). A primer layer 30 is laminated on the sealed members such as the power semiconductor chip 1, the laminated substrate 5, and the metal wire 10 to improve adhesion. A primer layer 30 is also provided inside the case, and a first sealing resin 8 is filled in contact with the primer layer 30. Furthermore, a protective substrate 31 is arranged in contact with the first sealing resin 8. The illustrated configuration of the power semiconductor module 50 is merely an example, and the present invention is not limited to this configuration.

[0028] In this manner, in the first embodiment, the protective substrate 31 is disposed on the outermost surface of the first sealing resin 8 to prevent moisture absorption from the upper part (outside) of the first sealing resin 8. For the protective substrate 31, an insulating material with zero water absorption, for example, a ceramic material, is used. The outermost surface of the resin portion, which is a water infiltration path to the power semiconductor module 50, is covered with a material with zero water absorption to physically cut moisture absorption. The material used for the protective substrate 31 is required to have zero water absorption as well as high pressure resistance and high heat resistance. An inorganic material is preferable, for example, a ceramic material is used. As described later, after filling the first sealing resin 8, before hardening, the back surface of the protective substrate 31 is attached to the surface of the first sealing resin 8, so that the protective substrate 31 and the first sealing resin 8 can be bonded together. Also, as described later, for bonding the protective substrate 31, an epoxy resin or the like having a linear expansion coefficient approximately intermediate between that of the first sealing resin 8 and the protective substrate 31 can be used. This is intended to reduce the thermal expansion difference with the protective substrate 31 and prevent cracking of the protective substrate 31 in addition to bonding.

[0029] Fig. 2 is an enlarged cross-sectional view of a portion A in Fig. 1 when the power semiconductor module according to the first embodiment absorbs moisture. As shown in Fig. 2, moisture absorption is prevented by the protective substrate 31, so that peeling can be prevented from occurring at the interface between the primer layer 30 and the module member (the first conductive plate 3 in Fig. 2).

[0030] (Power semiconductor chip 1) The power semiconductor chip 1 is a power chip such as an IGBT (Insulated Gate Bipolar Transistor) or a diode chip, and various Si devices, SiC devices, GaN devices, etc. may be used. These devices may also be used in combination. For example, a hybrid module using a Si-IGBT and a SiC-SBD may be used. The number of power semiconductor chips 1 mounted may be one or more.

[0031] A front surface electrode (back surface electrode) on the back surface of the power semiconductor chip 1 is joined to a first conductive plate 3 on the front surface of the laminated substrate 2 with a bonding layer 25 such as solder. A second conductive plate 4 on the back surface of the laminated substrate 2 is joined to the front surface of a heat dissipation base 26 with a bonding layer 25 such as solder. The first conductive plate 3 is formed in a predetermined circuit pattern on the front surface (first main surface) of the insulating substrate 2. The second conductive plate 4 may be a metal foil formed on the entire back surface of the insulating substrate 2.

[0032] (Laminated substrate 5) The laminated substrate 5 can be composed of an insulating substrate 2, a first conductive plate 3 formed in a predetermined shape on one of its main surfaces, and a second conductive plate 4 formed on the other main surface. The insulating substrate 2 can be made of a material having excellent electrical insulation and thermal conductivity. Examples of the material for the insulating substrate 2 include Al2O3, AlN, and SiN. In particular, for high voltage applications, a material having both electrical insulation and thermal conductivity is preferable, and AlN and SiN can be used, but are not limited to these. The first conductive plate 3 and the second conductive plate 4 can be made of metal materials such as Cu and Al, which have excellent workability. Among such conductive plates made of Cu and the like, a conductive plate that is not in contact with the power semiconductor chip 1 may be referred to as a back copper foil or a back conductive plate. The conductive plate may be Cu or Al that has been treated with Ni plating or the like for the purpose of rust prevention. Methods for disposing the conductive plate on the insulating substrate 2 include a direct copper bonding method and an active metal brazing method.

[0033] (Heat dissipation base 26) The heat dissipation base 26 is a heat dissipation plate having, for example, a substantially rectangular planar shape formed of metal such as Cu or Al having excellent thermal conductivity, and is also referred to as a metal substrate. The surface of the heat dissipation base 26 may be covered with a Ni film or Ni alloy film having an anti-corrosive effect. The back surface of the heat dissipation base 26 may be joined to a cooling base section (not shown). The heat dissipation base 26 conducts heat generated in the power semiconductor chip 1 and transmitted through the laminated substrate 5 to the heat dissipation fin section. The heat dissipation fin section has a plurality of heat dissipation fins and dissipates the heat conducted from the heat dissipation base 26. The heat dissipation base 26 itself may be a cooling device such as a heat dissipation fin section.

[0034] (Joining layer 25) The bonding layer 25 can be formed using lead-free solder. For example, Sn-Ag-Cu, Sn-Sb, Sn-Sb-Ag, Sn-Cu, Sn-Sb-Ag-Cu, Sn-Cu-Ni, Sn-Ag, etc. can be used, but are not limited to these. The bonding layer 25 can also be formed using a connecting material containing fine metal particles, such as a sintered body of nano-silver particles.

[0035] (Case 7) The lower end of the case 7 made of resin or the like is bonded to the periphery of the heat dissipation base 26. The case 7 has a generally rectangular cylindrical shape and surrounds the periphery of the front surface of the heat dissipation base 26. A box-shaped recess is formed with the front surface of the heat dissipation base 26 as the bottom surface and the inner wall of the case 7 perpendicular to the front surface of the heat dissipation base 26 as the side wall. The power semiconductor chip 1, which is wired with wiring members such as metal wires 10 and lead frames, the laminated substrate 5, and wiring member parts are stored inside this recess. The material of the case 7 may be, for example, a thermoplastic resin such as polyphenylene sulfide (PPS) or polybutylene terephthalate (PBT) or a thermosetting resin such as a phenolic resin.

[0036] (Primer layer 30) A primer layer 30 may be formed on the member to be sealed. The primer layer 30 may be a layer made of a resin containing polyamide, polyimide, or polyamideimide. The primer layer 30 may be advantageously used because it can improve the adhesion of the interface between the conductive connection member such as the metal wire 10 or the lead frame, the laminated substrate 5 (particularly the first conductive plate 3 on the main surface side), the heat dissipation base 26, the case 7 (inner surface), and the first sealing resin 8, and can relieve stress. The thickness of the primer layer 30 is not particularly limited as long as it can impart adhesion and relieve stress. The thickness of the primer layer 30 can be, for example, about 1 to 15 μm, and is preferably 2 to 10 μm. The primer layer 30 can be provided so as to cover the entire surface of the member. These primer layers 30 are prone to moisture absorption, and may lose their adhesion when they absorb moisture. Although not shown, the power semiconductor module may not have the primer layer 30.

[0037] (1st sealing resin 8) The first sealing resin 8 is used in the first sealing resin layer, and is provided in contact with the primer layer 30, or in a power semiconductor module not having the primer layer 30 (not shown), is provided in contact with the member to be sealed, and mainly covers the periphery of the power semiconductor chip 1, the laminated substrate 5, the metal wire 10, the lead frame, and the like. The surface of the first sealing resin 8 is at least partially covered by the protective substrate 31. Therefore, the first sealing resin 8 may constitute the surface of the sealing material, but is preferably provided in a manner that is not exposed to the surface of the sealing material, that is, is not in contact with the atmosphere such as the air. The first sealing resin 8 can be composed of a thermosetting resin composition, and is preferably composed of a highly heat-resistant thermosetting resin composition. The thermosetting resin composition includes a thermosetting resin main agent, and may optionally include an inorganic filler, a curing agent, a curing accelerator, and necessary additives. The thermosetting resin composition constituting the first sealing resin 8 may or may not include a fluorine-based silane coupling agent, but it is preferable that it does not include it. This is because the glass transition temperature (Tg) of the first sealing resin 8 may be lowered.

[0038] The thermosetting resin base is not particularly limited, and examples thereof include epoxy resin, phenolic resin, maleimide resin, etc. Among them, epoxy resin having at least two epoxy groups in one molecule is particularly preferred because of its high dimensional stability, water resistance, chemical resistance, and electrical insulation. Specifically, it is preferred to use aliphatic epoxy resin, alicyclic epoxy resin, or a mixture thereof.

[0039] Aliphatic epoxy resin refers to an epoxy compound in which the carbon to which the epoxy group is directly bonded is a carbon that constitutes an aliphatic hydrocarbon. Therefore, even if the main skeleton contains an aromatic ring, if the above condition is met, it is classified as an aliphatic epoxy resin. Examples of aliphatic epoxy resins include, but are not limited to, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD ​​type epoxy resins, biphenyl type epoxy resins, naphthalene type epoxy resins, cresol novolac type epoxy resins, and polyfunctional epoxy resins having three or more functional groups. These can be used alone or in combination of two or more types. In addition, naphthalene type epoxy resins and polyfunctional epoxy resins having three or more functional groups have a high glass transition temperature, and are therefore also referred to as high heat resistant epoxy resins. By including these high heat resistant epoxy resins, heat resistance can be improved.

[0040] The term "alicyclic epoxy resin" refers to an epoxy compound in which two carbon atoms constituting an epoxy group constitute an alicyclic compound. Examples of alicyclic epoxy resins include, but are not limited to, monofunctional epoxy resins, bifunctional epoxy resins, and trifunctional or higher polyfunctional epoxy resins. The alicyclic epoxy resin can be used alone or in combination with two or more different alicyclic epoxy resins. When an alicyclic epoxy resin is mixed with an acid anhydride curing agent and cured, the glass transition temperature increases, so that mixing an alicyclic epoxy resin with an aliphatic epoxy resin can improve heat resistance.

[0041] The thermosetting resin base material used in the composition according to the first embodiment may be a mixture of the above-mentioned aliphatic epoxy resin and alicyclic epoxy resin. The mixing ratio when mixing may be any, and the mass ratio of the aliphatic epoxy resin to the alicyclic epoxy resin may be about 2:8 to 8:2, or may be about 3:7 to 7:3, and is not limited to a specific mass ratio. Preferably, the thermosetting resin base material has a mass ratio of the bisphenol A type epoxy resin to the alicyclic epoxy resin of 1:1 to 1:4.

[0042] The thermosetting resin composition according to the first embodiment may contain an inorganic filler as an optional component. The inorganic filler may be a metal oxide or a metal nitride, and examples thereof include fused silica (fused silicon oxide), silica (silicon oxide), alumina (aluminum oxide), aluminum hydroxide, titania (titanium oxide), zirconia (zirconium oxide), aluminum nitride, talc, clay, mica, and glass fiber, but are not limited thereto. These inorganic fillers can increase the thermal conductivity of the cured product and reduce the thermal expansion coefficient. The linear expansion coefficient can be adjusted by the type and amount of inorganic filler to be added so as to be close to that of the laminated substrate, etc., thereby reducing the thermal stress between them. Specifically, the linear expansion coefficient of Cu, which is often used in the conductive layer of the laminated substrate 5, is 16 to 18 (×10 -6 / °C), the linear expansion coefficient α1 of the first sealing resin 8 is also 15 to 20 (×10 -6 / °C), which is about the same as the conductive layer, 16 to 18 (×10 -6 More preferably, the linear expansion coefficient of the epoxy resin itself is 40 to 70 (×10 -6 / ℃), the linear expansion coefficient is 0.5 to 0.6 (×10 -6 / ℃) silicon oxide and 7(×10 -6 By adding aluminum oxide of about 10 ...

[0043] The thermosetting resin composition may contain a curing agent as an optional component in addition to the thermosetting resin base, or in addition to the thermosetting resin base and the inorganic filler. The curing agent is not particularly limited as long as it reacts with the thermosetting resin base, preferably the epoxy resin base, and can be cured, but it is preferable to use an acid anhydride curing agent. Examples of the acid anhydride curing agent include aromatic acid anhydrides, specifically phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, etc. Alternatively, cyclic aliphatic acid anhydrides, specifically tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, etc., or aliphatic acid anhydrides, specifically succinic anhydride, polyadipic anhydride, polysebacic anhydride, polyazelaic anhydride, etc., can be mentioned. The amount of the curing agent is preferably 50 parts by mass or more and 170 parts by mass or less, and more preferably 80 parts by mass or more and 150 parts by mass or less, relative to 100 parts by mass of the epoxy resin base. If the amount of the curing agent is less than 50 parts by mass, the glass transition temperature may decrease due to insufficient crosslinking, and if it is more than 170 parts by mass, it may be accompanied by a decrease in moisture resistance, high heat distortion temperature, and heat resistance stability. In addition, when a bisphenol A type epoxy resin is used alone or a mixture of a bisphenol A type epoxy resin and a high heat resistant epoxy resin exemplified above is used as the thermosetting resin base, it may be preferable not to use a curing agent because heat resistance is improved. The compounding ratio of the high heat resistant epoxy resin may be, for example, 10% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 25% by mass or less, when the total mass of the thermosetting resin base is 100%. This range is preferable because heat resistance is improved and viscosity does not increase.

[0044] The thermosetting resin composition may further contain a curing accelerator as an optional component. As the curing accelerator, imidazole or its derivative, tertiary amine, boric acid ester, Lewis acid, organometallic compound, organic acid metal salt, etc. may be appropriately blended. The amount of the curing accelerator added is preferably 0.01 parts by mass or more and 50 parts by mass or less, more preferably 0.1 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the epoxy resin base.

[0045] The thermosetting resin composition may also contain optional additives to the extent that the properties are not impaired. Examples of additives include, but are not limited to, flame retardants, pigments for coloring the resin, and plasticizers and silicon elastomers for improving crack resistance. These optional components and the amounts of the additives can be appropriately determined by those skilled in the art according to the specifications required for the semiconductor device and / or the encapsulant. The first encapsulating resin 8 composed of the above-mentioned thermosetting resin composition may also absorb moisture and react with a very small amount of uncured components to deteriorate. Therefore, the deterioration of the resin of the first encapsulating resin 8 can be suppressed by being protected by the waterproof and moisture-proof effects of the protective substrate 31 described later. In addition, when the primer layer 30 is provided, the primer layer 30 has a higher hygroscopicity than the resin of the first encapsulating resin 8, and as a result, the adhesion may decrease. Therefore, the present invention shows a higher effect in a structure having the primer layer 30.

[0046] The thickness of the first sealing resin 8 must be sufficient to cover the members to be sealed, such as the laminated substrate 5 and the wiring members, and is approximately 3 mm to 8 mm.

[0047] (Protection board 31) A ceramic substrate having a low water absorption rate is used for the protective substrate 31. Specifically, zirconium oxide, aluminum oxide, silicon oxide, silicon carbide, and silicon nitride are preferable. However, since the protective substrate 31 is bonded to the first sealing resin 8, it is preferable that the linear expansion coefficient of the protective substrate 31 is close to that of the first sealing resin 8 to be bonded, in order to suppress thermal stress to a low level. The linear expansion coefficient α1 of the first sealing resin 8 and the linear expansion coefficient α of the protective substrate 31 arep If the difference between these is large, it is not preferable because the first sealing resin 8 and the protective substrate 31 may peel off due to thermal stress. p (Equation 1), as described later, the linear expansion coefficient α p is 11 (×10 -6 / ℃) zirconium oxide, 7(×10 -6 / °C), the difference between the linear expansion coefficient of the first sealing resin 8 and that of aluminum oxide is 10(×10 -6 / °C), and since the thermal stress is small, peeling is difficult to occur, which is particularly preferable.

[0048] The thickness of the protective substrate 31 is preferably thicker than 0.2 mm in terms of waterproofing, moisture resistance, and rigidity, and is preferably 1 mm or less in terms of weight and cost. The protective substrate 31 is disposed on the upper surface of the first sealing resin 8. FIG. 3 is a cross-sectional view showing another structure of the protective substrate and sealing resin of the power semiconductor module according to the first embodiment. As shown in FIG. 3, the first sealing resin 8 may be inserted between the end of the protective substrate 31 and the case 7, or the first sealing resin 8 may be bonded so as to contact a part of the upper surface of the protective substrate 31. When the first sealing resin 8 is formed on the end or part of the upper surface of the protective substrate 31 in this manner, the adhesion between the protective substrate 31 and the first sealing resin 8 is improved, the protective substrate 31 is less likely to peel off, and water and the like are less likely to penetrate, which is preferable. In addition, the first sealing resin 8 between the end of the protective substrate 31 and the case 7 serves as a stress relaxation layer, so that peeling at the interface in contact with the first sealing resin 8 is prevented.

[0049] (Method of manufacturing the power semiconductor module according to the first embodiment) Next, a method for manufacturing the power semiconductor module according to the first embodiment will be described. First, the power semiconductor chip 1 is bonded to the heat dissipation base 26 and the laminated substrate 5, and the case 7 is attached to the heat dissipation base 26. After that, the lead frame is bonded and wire bonding is performed with the metal wire 10. Next, the primer layer 30 may be formed. The primer layer 30 can be provided on the power semiconductor chip 1, the laminated substrate 5, the lead frame, the metal wire 10, and the case 7 by, for example, spray coating. After the primer layer 30 is formed, it is preferable to heat the lead frame at 70 to 90°C for about 60 to 80 minutes in an inert oven into which nitrogen gas is introduced, and further heat the lead frame at 200 to 220°C for 60 to 80 minutes. This heating operation suppresses oxidation of the Cu surface and heats the Cu constituting the lead frame, promoting the reaction between the primer layer 30 and Cu, and improving the adhesion between the primer layer 30 and the lead frame. The power semiconductor module 50 of the present embodiment 1 may be a power semiconductor module 50 not provided with the primer layer 30, in which case the spray coating and heating operations in an inert oven can be omitted. Next, a thermosetting resin composition constituting the first sealing resin 8 is injected into the case 7 and cured by heating. The thermosetting resin composition constituting the first sealing resin 8 at the time of injection preferably has a storage modulus (G') of about 1 Pa to 1000 Pa. If it is within this range, voids occurring in the resin can be reduced.

[0050] Next, the sealing resin is filled into the case 7, provisionally cured at 100 to 120°C for 10 to 120 minutes as the first sealing resin 8, and the protective substrate 31 is placed on the upper surface of the first sealing resin 8 and fully cured at about 175 to 185°C for 1 to 2 hours to form the first sealing resin 8. It is preferable to adjust the storage modulus (G'), which is the elastic component of the viscoelasticity during provisional curing, to a range of 1 kPa to 1 MPa, since the protective substrate 31 can be adhered without gaps. If it exceeds 1 MPa, it is not preferable because it becomes hard and it becomes difficult to attach the protective substrate 31 without deformation. The storage modulus (G') can be adjusted by the heating temperature and time, and the storage modulus (G') can be measured by a vibration rheometer. Alternatively, the protective substrate 31 may be placed on the upper surface of the uncured first sealing resin 8 without provisional curing, and fully cured. However, if provisional curing is not performed, thermal stress acts on the protective substrate 31 due to thermal contraction of the sealing resin material, making it easy to deform or peel off, so provisional curing is preferable.

[0051] As described above, according to the semiconductor module and the manufacturing method of the semiconductor module of the first embodiment, by disposing the protective substrate on the upper surface of the first sealing resin, the moisture-proof performance is improved, and the occurrence of peeling that causes insulation failure due to deterioration of the sealing resin itself and the decrease in adhesion between the primer layer and the module components is suppressed, and a more reliable power semiconductor module can be obtained. In addition, the protective substrate is preferably made of zirconium oxide, aluminum oxide, silicon oxide, silicon carbide, or silicon nitride, and zirconium oxide and aluminum oxide, which have a small difference in linear expansion coefficient with the first sealing resin, are more preferable.

[0052] (Embodiment 2) 4 is a cross-sectional view showing details of the periphery of the protective substrate of the power semiconductor module according to the second embodiment. Other structures are the same as those of the first embodiment, and therefore descriptions thereof will be omitted. In the second embodiment, a second sealing resin 8a (second sealing resin layer) is provided between the first sealing resin 8 and the protective substrate 31. The first sealing resin 8 and the protective substrate 31 are the same as those of the first embodiment, and therefore descriptions thereof will be omitted.

[0053] 4, the protective substrate 31 is bonded by a thin layer of a second sealing resin 8a provided on the first sealing resin 8 that seals the power semiconductor module 50. The second sealing resin 8a not only acts as an adhesive to connect the first sealing resin 8 and the protective substrate 31, but also serves to reduce the linear expansion coefficient α2 of the second sealing resin 8a by the linear expansion coefficient α1 of the first sealing resin 8 and the linear expansion coefficient α of the protective substrate 31. p By setting the value to the middle of these, it also acts as a relaxation layer for the stress generated by the difference in thermal expansion. In other words, α1>α2>α p (Formula 2) is preferable. In addition, the difference between the linear expansion coefficient of the second sealing resin 8a and the linear expansion coefficient of the protective substrate 31 is preferably 10(×10 -6 When the temperature is less than 100° C. / ° C., the thermal stress is small and peeling is difficult to occur, which is particularly preferable.

[0054] The second sealing resin 8a can use the base material and additives of the first sealing resin 8. In the case of the same type of base material, the adhesion between the second sealing resin 8a and the first sealing resin 8 is good, which is preferable. However, in order to satisfy the linear expansion coefficient α2 of the second sealing resin 8a in (Equation 2), it is preferable to adjust the type and amount of inorganic filler added. In addition, the thickness of the second sealing resin 8a is preferably 0.3 mm or more, and is preferably thinner than the film thickness of the first sealing resin 8. If (Equation 2) is satisfied and the film thickness is within this range, peeling does not occur between the second sealing resin 8a and the protective substrate 31, and between the second sealing resin 8a and the first sealing resin 8 due to the stress relaxation effect. In addition, if the thickness of the second sealing resin 8a exceeds 3 mm, peeling may occur at the interface with the protective substrate 31, so the thickness of the second sealing resin 8a is more preferably 0.3 mm or more and 3 mm or less. In addition, the difference in the linear expansion coefficient between the first sealing resin 8 and the second sealing resin 8a is also 10(×10 -6 If the temperature is less than 5(×10 / °C), the thermal stress is small and peeling is difficult, which is preferable. -6 / °C).

[0055] (Method of manufacturing a power semiconductor module according to the second embodiment) Next, a method for manufacturing the power semiconductor module according to the second embodiment will be described. As in the first embodiment, the process starts with joining the power semiconductor chip 1 to the heat dissipation base 26 and the laminated substrate 5, followed by injecting a thermosetting resin composition constituting the first sealing resin 8 into the case 7 and curing it by heating.

[0056] Next, the first sealing resin 8 is fully cured. After that, the second sealing resin 8a is applied to the upper surface of the first sealing resin 8 to a predetermined thickness using a dispenser or the like. Then, it is provisionally cured at 100 to 120°C for 10 to 120 minutes, and the protective substrate 31 is placed on the upper surface of the second sealing resin 8a and fully cured at about 175 to 185°C for 1 to 2 hours to form the protective substrate. It is preferable to adjust the storage modulus (G'), which is the elastic component of the viscoelasticity during provisional curing, to a range of 1 kPa to 1 MPa, since this allows the protective substrate 31 to be tightly attached without any gaps.

[0057] Alternatively, the second sealing resin 8a may be applied to the rear surface of the protective substrate 31 to a predetermined thickness, and temporarily cured at 100 to 120°C for 10 to 120 minutes before pasting. It is preferable to adjust the storage modulus (G'), which is the elastic component of the viscoelasticity during the temporary curing, to a range of 1 kPa to 1 MPa. The protective substrate 31 may be placed so that the second sealing resin 8a faces the upper surface of the fully cured first sealing resin 8, and then the resin may be fully cured at about 175 to 185°C for 1 to 2 hours. Alternatively, the second sealing resin 8a may be applied to the rear surface of the protective substrate 31 to a predetermined thickness without temporary curing, the protective substrate 31 may be placed so that the second sealing resin 8a faces the upper surface of the fully cured first sealing resin 8, and then the resin may be fully cured at about 175 to 185°C for 1 to 2 hours. However, if the temporary curing is not performed, thermal stress acts on the protective substrate 31 due to thermal contraction of the resin material of the second sealing resin 8a, which makes it easy to deform or peel off, so it is preferable to perform the temporary curing.

[0058] As described above, according to the semiconductor module and the manufacturing method of the semiconductor module of the second embodiment, the second sealing resin is disposed between the first sealing resin and the protective substrate. This reduces the difference in linear expansion coefficient between the first sealing resin, the second sealing resin, and the protective substrate, and reduces the thermal stress caused by the difference in linear expansion coefficient. Therefore, even if a sudden temperature change occurs, peeling can be prevented at the interface between the first sealing resin and the second sealing resin and the interface between the second sealing resin and the protective substrate, and the reliability of the power semiconductor module can be further improved.

[0059] (Example) The present invention will be described in more detail below with reference to examples of the present invention. However, the present invention is not limited to the scope of the following examples. FIG. 5 shows the structures of the first sealing resin, the second sealing resin, and the protective substrate of the examples and comparative examples, as follows: Structure 1 is a conventional structure without a protective substrate, Structure 2 is a structure in which a protective substrate is provided on the first sealing resin, and Structure 3 is a structure in which a second sealing resin is provided between the first sealing resin and the protective substrate, and is a table showing the properties (water absorption rate, linear expansion coefficient) of each layer. FIG. 6 is a table showing the properties of each material used in the configuration of the first sealing resin, the second sealing resin, and the protective substrate of the examples and comparative examples. FIG. 7A is a table showing mainly the evaluation results of the examples and comparative examples of the first embodiment. FIG. 7B is a table showing the evaluation results of the examples and comparative examples of the second embodiment. Here, the water absorption rate is calculated by (M-M0) / M0 (wt%), where M0 is the mass of the sample before moisture absorption and M is the mass of the sample after moisture absorption. The water absorption rate was evaluated by leaving the sample in a thermo-hygrostat at a temperature of 85° C. and a humidity of 85% for 312 hours and measuring the mass before and after moisture absorption.

[0060] (1) Manufacture of power semiconductor modules (Examples 1 to 3) In Examples 1 to 3, the power semiconductor module 50 shown in FIG. 1 was manufactured. The primer layer 30 was formed on the power semiconductor chip 1, the lead frame, the laminated substrate 5, the case 7, and the metal wire 10 by using Himal HL1200FM (Hitachi Chemical), whose main component is polyamide, with a thickness of 10 μm. The first sealing resin 8 was manufactured by heat-curing a thermosetting resin compound containing a thermosetting resin, a curing agent, and an inorganic filler. As the thermosetting resin base, ME276 (manufactured by Pernox), a mixture of bisphenol A type epoxy and alicyclic epoxy in a mass ratio of 3:2, was used, and HV-138 (manufactured by Pernox) was added as an acid anhydride-based curing agent in a mass ratio of 1:1 to the epoxy resin base. In Examples 1 to 3, the inorganic filler was silicon oxide (manufactured by AGC) with an average particle size of 40 μm, and was added in an amount of 73 mass% when the total mass of the epoxy resin base agent, curing agent, and inorganic filler was taken as 100%, and the linear expansion coefficient was 16 (× 10 -6 / °C) (sealing resin 1). The first sealing resin 8 was provisionally cured at 100 to 120°C for 10 to 120 minutes, and the back surface of the protective substrate 31 was placed so as to be entirely in contact with the upper surface of the first sealing resin 8, and was fully cured at about 175 to 185°C for 1 to 2 hours.

[0061] Examples 1 to 3 have the structure of power semiconductor module 50 according to embodiment 1, which is structure 2 in Fig. 5. The first sealing resin 8 and protective substrate 31 are as shown in the columns for Examples 1 and 2 in Fig. 7A, and the thickness of protective substrate 31 is 0.5 mm.

[0062] (Examples 4 to 13) Examples 4 to 13 have the structure of the power semiconductor module 50 according to the second embodiment, which is structure 3 in FIG. 5, and the first sealing resin 8, the second sealing resin 8a, and the protective substrate 31 are as shown in FIG. 7B. Specifically, sealing resins 2 and 3 were prepared as the second sealing resin 8a. The sealing resin 2 had silicon oxide (manufactured by AGC) with an average particle size of 40 μm added as an inorganic filler so that the amount was 80 mass % when the total mass of the epoxy resin base agent, hardener, and inorganic filler was taken as 100%, and the linear expansion coefficient was set to 14 (×10 -6 / °C). Silicon oxide (manufactured by AGC) with an average particle size of 40 μm was added as an inorganic filler to the sealing resin 3 so that the total mass of the epoxy resin base agent, hardener, and inorganic filler was 100%, and the linear expansion coefficient was 12 (×10 -6 / ℃).

[0063] Fig. 8 is a cross-sectional view showing the details of the periphery of the protective substrate of Examples 4 to 13. Fig. 8 shows an example in which aluminum oxide (linear expansion coefficient α=7) is used for the protective substrate 31, and epoxy resin with linear expansion coefficient α=16 is used for the first sealing resin 8. In this case, epoxy resin with linear expansion coefficient α=12, 14, which is an intermediate value, is used for the second sealing resin 8a. As described above, the linear expansion coefficient α of the second sealing resin 8a is adjusted by, for example, adjusting the amount of inorganic filler added in the resin. It is also possible to adjust by changing the type of inorganic filler.

[0064] Examples 4 to 13 were manufactured in the same manner as Examples 1 to 3, except that the second sealing resin 8a was formed. After the first sealing resin 8 was cured, a second sealing resin material to which an inorganic filler was added so as to have a linear expansion coefficient α shown in Fig. 7B was applied to the surface of the cured first sealing resin 8 so as to have a film thickness of 0.5 mm, and was provisionally cured at 100 to 120°C for 10 to 120 minutes. Thereafter, the protective substrate 31 was placed so as to be in contact with the surface of the second sealing resin 8a, and was fully cured at about 175 to 185°C for 1 to 2 hours.

[0065] Comparative Example 1 Comparative Example 1 is a conventional structure in which only the first sealing resin 8 is used and no protective substrate 31 is provided. This corresponds to Structure 1 in Fig. 5. A power semiconductor module was manufactured in the same manner as in Examples 1 to 3, except that no protective substrate 31 was provided.

[0066] (2) Power cycle test (P / C tolerance test) A power cycle test for evaluating the reliability of a semiconductor module is carried out as follows. The power semiconductor module manufactured in (1) above is first left in an environment of 85°C and 85% RH (relative humidity) for 300 hours to absorb moisture. This moisture absorption treatment is an accelerated condition for reliability, and the module must satisfy the power cycle resistance described below even after being left in an environment of 85°C and 85% RH for 300 hours.

[0067] After the moisture absorption treatment, a power cycle test was performed at 40℃ to 175℃, with one cycle consisting of 2 seconds of power operation and 9 seconds of rest. The number of cycles until no abnormalities occurred in the electrical characteristics was determined as the P / C resistance. The evaluation was made as follows: 40k cycles (kcyc) or more is preferable, with the power cycle resistance rated as "◯", those without abnormalities up to 100k cycles were rated as "◎", and those that showed abnormalities in the electrical characteristics such as disconnection or abnormal current before reaching 20k cycles were rated as "×". The results are shown in Figures 7A and 7B.

[0068] (3) Micro-peeling observation The power semiconductor module manufactured in (1) above was subjected to the power cycle test in (2) above up to 40k cycles, and peeling around the protective substrate and the laminated substrate was observed using an ultrasonic flaw detection manufacturing device (SAT: Scanning Acoustic Tomograph). Peeling around the laminated substrate is particularly undesirable as it may affect the reliability of the power semiconductor module. Those with no peeling were rated as "Good", those with peeling less than 30 μm in length were rated as "Good", and those with peeling of 50 μm or more were rated as "Poor".

[0069] (result) 7A and 7B show evaluations of P / C resistance and micro peeling. As shown in FIG. 7A, in the power semiconductor module (Comparative Example 1) having a conventional structure without a protective substrate, peeling was observed around the laminated substrate when the module was subjected to moisture absorption treatment, and the P / C resistance was 20k cycles or less. However, as shown in FIG. 7A of the first embodiment, the power semiconductor modules of Examples 1 to 3 in which protective substrates made of zirconium oxide, aluminum oxide, and silicon oxide were disposed on the upper surface of the sealing resin had a good P / C resistance of 40k cycles or more. Although the reliability of the power semiconductor module was satisfied, in Examples 1 to 3, micro peeling with a length of less than 30 μm was observed between the protective substrate and the first sealing layer. This is considered to be due to peeling caused by thermal stress due to a slightly large difference in the linear expansion coefficient between the protective substrate and the first sealing resin. In addition, when the protective substrate was silicon oxide (Example 3), zirconium oxide (Example 1), and aluminum oxide (Example 2), the length of peeling was about the same, but the silicon oxide had more peeled parts. This is believed to be because the difference in linear expansion coefficient between the protective substrate and the first sealing resin is larger. In other words, in the case of the first embodiment, the difference (Δα) between the linear expansion coefficient of the protective substrate and the first sealing resin 8 is 10 (×10 -6 / °C), and smaller thermal stress is more preferable since peeling is less likely to occur.

[0070] FIG. 7B shows the evaluation of P / C resistance and micro-peeling for Structure 3 in which the second sealing resin was provided. The power semiconductor modules of Examples 4 to 13 in which protective substrates of zirconium oxide, aluminum oxide, silicon carbide, silicon nitride, and silicon oxide were arranged had good P / C resistance of 40k cycles or more. In particular, in the cases of Examples 4, 5, 9, and 10, the moisture resistance was improved by providing the protective substrate, so the P / C resistance was good at 100k cycles or more, and no peeling was observed around the laminated substrate or the protective substrate. This is the case when zirconium oxide or aluminum oxide was used as the protective substrate, and the difference in the linear expansion coefficient between the second sealing resin and the protective substrate was 7(×10 -6 / °C), which is thought to be because the thermal stress was small and peeling was less likely to occur.

[0071] In addition, in the cases of Examples 6 to 8 and 11 to 13, the P / C resistance was good, being 40k cycles or more. In the cases of Examples 6 to 8 and 13, the reliability required for a power semiconductor module was satisfied, but minute peeling was observed between the protective substrate and the first sealing resin. This was less severe than in Examples 1 to 3, and the length of the peeling was about 10 μm. This is because the difference in the linear expansion coefficient between the protective substrate and the second sealing resin was 10(×10 -6 / °C), it is believed that the microscopic peeling occurred due to thermal stress. In other words, in the case of the second embodiment, the difference in the linear expansion coefficient between the protection substrate and the second sealing resin is 10(×10 -6 / ℃), and 7(×10 -6 / °C) or less is more preferable.

[0072] From the above results, by placing the protective substrate on the upper surface of the sealing resin, the moisture-proof performance was improved, and the reliability of the semiconductor module was improved. In addition, by providing the second sealing resin so as to satisfy the formula (2), the thermal stress between the protective substrate and the sealing layer was reduced, and peeling between the protective substrate and the sealing resin was suppressed. The protective substrate is preferably made of zirconium oxide, aluminum oxide, silicon oxide, silicon carbide, or silicon nitride, and zirconium oxide and aluminum oxide, which have a small difference in linear expansion coefficient with the sealing resin, are more preferable.

[0073] The present invention can be modified in various ways without departing from the spirit of the present invention, and in each of the above-mentioned embodiments, for example, the dimensions of each part and the impurity concentration are set in various ways according to the required specifications, etc. Also, in each of the above-mentioned embodiments, the semiconductor can be applied to wide band gap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) in addition to silicon. [Industrial Applicability]

[0074] INDUSTRIAL APPLICABILITY As described above, the semiconductor module and the method for manufacturing the semiconductor module according to the present invention are useful for power semiconductor modules used in power conversion devices such as inverters, power supply devices for various industrial machines, igniters for automobiles, and the like. [Explanation of symbols]

[0075] 1, 101 Power semiconductor chip 2, 102 Insulating substrate 3, 103 First conductive plate 4, 104 Second conductive plate 5, 105 Laminated board 7, 107 cases 8 First sealing resin 8a Second sealing resin 9, 109 Metal terminal 10, 110 Metal Wire 25, 125 bonding layer 26, 126 Heat dissipation base 30, 130 Primer layer 31 Protection Board 50, 150 Power Semiconductor Module 108 Sealing resin 132 Peeling

Claims

1. A laminated substrate having a semiconductor element mounted thereon; A metal substrate carrying the laminated substrate; a case to which the metal substrate is bonded with an adhesive; a first sealing resin filled in the case; a protection substrate disposed on the first sealing resin; a second sealing resin between the first sealing resin and the protection substrate; Equipped with A semiconductor module, wherein a linear expansion coefficient α 1 of said first sealing resin, a linear expansion coefficient α p of said protection substrate, and a linear expansion coefficient α 2 of said second sealing resin satisfy α 1 >α 2 >α p .

2. A laminated substrate on which a semiconductor element is mounted, A metal substrate carrying the laminated substrate; a case to which the metal substrate is bonded with an adhesive; a first sealing resin filled in the case; a protection substrate disposed on the first sealing resin; Equipped with A semiconductor module, characterized in that a primer layer made of a resin containing polyamide, polyimide, or polyamideimide is applied to the surfaces of the semiconductor element, the laminated substrate, and the case.

3. A semiconductor module as described in claim 1 or 2, characterized in that the protective substrate is a ceramic substrate.

4. The linear expansion coefficient α of the first sealing resin 1 and the linear expansion coefficient α of the protective substrate p The difference is 10 x 10 -6 2. The semiconductor module according to claim 1, wherein the temperature is less than 100° C. / ° C.

5. The semiconductor module according to claim 1, wherein a difference between a linear expansion coefficient α 2 of the second sealing resin and a linear expansion coefficient α p of the protective substrate is less than 10×10 -6 / °C.

6. A first step of mounting a semiconductor element on a laminate substrate; a second step of mounting the laminated substrate on a metal substrate; a third step of adhering the metal substrate to a case with an adhesive; a fourth step of filling the case with a first sealing resin; a fifth step of disposing a protection substrate on the first sealing resin; Including, After the fourth step and before the fifth step, A sixth step of providing a second sealing resin on the first sealing resin, In the fifth step, the protection substrate is disposed on the second sealing resin; A method for manufacturing a semiconductor module, wherein a linear expansion coefficient α 1 of said first sealing resin, a linear expansion coefficient α p of said protection substrate, and a linear expansion coefficient α 2 of said second sealing resin satisfy α 1 >α 2 >α p .

7. A first step of mounting a semiconductor element on a laminate substrate; a second step of mounting the laminated substrate on a metal substrate; a third step of adhering the metal substrate to a case with an adhesive; a fourth step of filling the case with a first sealing resin; a fifth step of disposing a protection substrate on the first sealing resin; Including, A method for manufacturing a semiconductor module, wherein in the fifth step, the first sealing resin is provisionally cured, the protective substrate is placed on an upper surface of the first sealing resin, and the first sealing resin is fully cured.

8. A first step of mounting a semiconductor element on a laminate substrate; a second step of mounting the laminated substrate on a metal substrate; a third step of adhering the metal substrate to a case with an adhesive; a fourth step of filling the case with a first sealing resin; a fifth step of disposing a protection substrate on the first sealing resin; Including, After the fourth step and before the fifth step, A sixth step of providing a second sealing resin on the first sealing resin, A method for manufacturing a semiconductor module, wherein in the fifth step, the second sealing resin is provisionally cured, the protective substrate is placed on an upper surface of the second sealing resin, and the second sealing resin is finally cured.

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