Method for manufacturing power module and power module

Abstract

[Project] The objective is to provide a method for manufacturing a power module with low void generation during molding and excellent reliability. [Solution] As a method for manufacturing a power module, the following (1) to (4) (1) A batching process in which a solid thermosetting resin composition at 25°C is placed in a container housing an insulating substrate on which a plurality of semiconductor devices are mounted, (2) Next, the container in which the thermosetting resin composition is placed is placed in a molding device capable of heating, pressurizing, and depressurizing, and the thermosetting resin composition is heated and melted in a melting process. (3) After that, a pressure reduction process in which the molding device is reduced pressure at least once and pressurized at least once, (4) Additionally, a curing process in which the thermosetting resin composition is cured by heating the inside of the molding device. A method for manufacturing a power module characterized by including the process of

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a power module and a power module. Background Technology

[0002] Recently, power modules are being utilized in a wide range of fields, including hybrid vehicles, electric vehicles, railways, and generators. Recently, there has been an increasing demand for high performance in power modules, such as increased rated voltage and current, and expanded operating temperature ranges.

[0003] The package structure of a power module is such that a power semiconductor device is mounted on an insulating substrate interposed on a heat dissipation base plate, and a case is bonded to the base plate. Silicone gel is generally used as the encapsulation material for the power module (Patent Document 1).

[0004] However, in recent use in high-temperature environments, the silicone gel hardens and cracks due to insufficient heat resistance, and the silicone gel decomposes to generate low-volatility components and form bubbles, causing delamination between the silicone gel and the insulating substrate. Consequently, problems such as reduced insulation reliability of the power module are occurring.

[0005] To solve this problem, liquid epoxy resin is being considered as a sealing material to replace silicone gel (Patent Document 2). Liquid epoxy resin, which is generally used as a sealing material for power modules, contains a large amount of inorganic filler because it is close to the coefficient of linear expansion of the insulating substrate in order to suppress warping after sealing.

[0006] As a result, the viscosity of the liquid epoxy resin increases, leading to problems such as voids not disappearing after encapsulation and cracking or delamination.

[0007] Furthermore, the resins used in liquid epoxy resins generally contain CMR substances (substances considered to be carcinogenic, mutagenic, and reproductive toxic), and there is a possibility that their use is restricted in the environmentally conscious EU. Prior art literature

[0008] Japanese Patent Publication No. 2012-79914 Japanese Patent Publication No. 2020-35965 The problem to be solved

[0009] Accordingly, the present invention aims to provide a method for manufacturing a power module with low void generation during molding and excellent reliability. means of solving the problem

[0010] To solve the above problem, the present invention,

[0011] As a method for manufacturing a power module, the following (1) to (4)

[0012] (1) A batching process in which a solid thermosetting resin composition at 25°C is placed in a container housing an insulating substrate on which a plurality of semiconductor devices are mounted,

[0013] (2) Next, the container in which the thermosetting resin composition is placed is placed in a molding device capable of heating, pressurizing, and depressurizing, and the thermosetting resin composition is heated and melted in a melting process.

[0014] (3) After that, a pressure reduction process in which the molding device is reduced pressure at least once and pressurized at least once,

[0015] (4) Additionally, a curing process in which the thermosetting resin composition is cured by heating the inside of the molding device.

[0016] A method for manufacturing a power module including the process is provided.

[0017] With this manufacturing method, it is possible to provide a power module that is free from voids or cracks during molding, has excellent reliability, and does not contain CMR material.

[0018] At this time, in the melting process (2), it is preferable to set the heating temperature above the melting point or softening point of the thermosetting resin composition and below 200°C.

[0019] At this temperature, viscosity is kept low to prevent voids or incomplete filling, and internal or surface voids can be removed without the thermosetting resin composition curing.

[0020] In addition, at this time, in the melting process (2), it is preferable to set the heating rate during heating to 0.5℃ / min to 50℃ / min.

[0021] With this heating rate, the resin does not thicken, and the resin can also be completely melted.

[0022] Furthermore, in the above-mentioned pressure reduction process (3), it is preferable to repeat the pressure reduction and / or pressure increase two or more times.

[0023] By repeating the application of pressure multiple times, internal or surface voids can be effectively removed.

[0024] In addition, in the pressurization process of the above pressurization and depressurization process (3), it is preferable to pressurize to 0.1 MPa to 10 MPa.

[0025] Within this range, no voids remain on the surface, and the resin penetrates sufficiently into the narrow parts, and the resin does not overflow.

[0026] In addition, in the pressure reduction process of the above pressure reduction process (3), it is preferable to reduce the pressure to 670 Pa to 90,000 Pa.

[0027] Within this range, the thermosetting resin composition does not overflow, and the degassing effect by reduced pressure becomes sufficient.

[0028] In addition, in the pressure reduction process of the above pressure reduction process (3), it is preferable to set the pressure reduction speed from atmospheric pressure to the set pressure level to 100 to 60,000 Pa / second.

[0029] Within this range, there is no risk of the thermosetting resin composition thickening or overflowing.

[0030] In addition, in the above batching process (1), it is preferable to place the thermosetting resin composition in an area of ​​30% to 95% of the bag area.

[0031] With this area, there is no risk of underfilling or resin leakage.

[0032] In addition, the present invention provides a power module encapsulated in a cured product of a thermosetting resin composition, wherein the number of internal voids with a diameter of 100 μm or more in the cured product is 10 / cm² 3 Provides a power module of the following size.

[0033] These power modules are free of voids and cracks and have excellent reliability. Effects of the invention

[0034] As described above, with the manufacturing method of the present invention, a power module can be obtained that is free from voids or cracks during molding, has excellent reliability, and does not contain CMR material. Brief explanation of the drawing

[0035] Figure 1 is an example of a graph plotting the relationship between dimensions and temperature for the results of measuring the dimensional change of a test specimen between 25°C and 300°C, and shows a method for determining the glass transition temperature. Figure 2 shows a placement process in which a solid thermosetting resin composition at 25°C is placed in a container housing an insulating substrate on which a plurality of semiconductor devices are mounted. Figure 3 shows a process of placing a container containing a thermosetting resin composition into a molding device capable of heating, pressurizing, and depressurizing. Specific details for implementing the invention

[0036] As mentioned above, there was a demand for a method of manufacturing a power module that is free from voids or cracks during molding, has excellent reliability, and does not contain CMR materials.

[0037] The inventors, having conducted repeated research to solve the above problem, discovered that a power module manufactured by placing a solid thermosetting resin composition at 25°C in a container housing an insulating substrate equipped with a plurality of semiconductor elements, placing the container containing the resin composition in a molding container capable of heating, pressurizing, and depressurizing, heating, and melting the resin composition, and then, after the resin is melted, depressurizing and pressurizing the inside of the molding container and further heating the inside of the molding container to cure the resin, provides a power module with excellent reliability and no voids or cracks on the surface or inside of the resin, thereby completing the present invention.

[0038] That is, the present invention is,

[0039] As a method for manufacturing a power module, the following (1) to (4)

[0040] (1) A batching process in which a solid thermosetting resin composition at 25°C is placed in a container housing an insulating substrate on which a plurality of semiconductor devices are mounted,

[0041] (2) Next, the container in which the thermosetting resin composition is placed is placed in a molding device capable of heating, pressurizing, and depressurizing, and the thermosetting resin composition is heated and melted in a melting process.

[0042] (3) After that, a pressure reduction process in which the molding device is reduced pressure at least once and pressurized at least once,

[0043] (4) Additionally, a curing process in which the thermosetting resin composition is cured by heating the inside of the molding device.

[0044] It is a method for manufacturing a power module that includes the process of.

[0045] The present invention will be described in detail below, but the invention is not limited to these.

[0046] [Method for manufacturing a power module]

[0047] (1) Batch process

[0048] In the (1) batching process of the manufacturing method of the present invention, a solid thermosetting resin composition at 25°C is placed in a container that houses an insulating substrate on which a plurality of power semiconductor devices are mounted. The container for placement may be equipped with a case or mold made of a thermoplastic resin such as polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, or polyethylene naphthalate (PEN) resin. Specifically, it is shown in FIG. 2.

[0049] In FIG. 2, a container (1) containing an insulating substrate equipped with a plurality of semiconductor elements is composed of a container (5) and an insulating substrate (4) within it, and a power semiconductor element (3) and a bonding wire (2) are provided on the insulating substrate (4). (1) In the placement process, a thermosetting resin composition (6) is placed on the power semiconductor element (3) on the insulating substrate (4) inside the case.

[0050] The above thermosetting resin composition can be appropriately placed at the location where the encapsulation is performed.

[0051] In addition, regarding resin filling capacity, void reduction, and prevention of resin leakage, it is preferable to arrange the thermosetting resin composition so that it covers an area of ​​30% to 95% of the bag area, more preferable to cover 40% to 90%, and even more preferable to cover 45% to 85%. If it is arranged to cover an area of ​​30% or more of the bag area, there is almost no risk of underfilling, and if it is arranged to cover an area of ​​95% or less, there is no risk of resin leakage.

[0052] Meanwhile, if there is a case or border, it is preferable to place it inside.

[0053] (2) Melting process

[0054] In this process, a container containing a thermosetting resin composition is placed inside a molding container (molding device) capable of heating, pressurizing, and depressurizing, heated, and the thermosetting resin composition is melted. The temperature of the thermosetting resin composition when melting the thermosetting resin composition can be appropriately adjusted according to the softening point or melting point of the thermosetting resin used; however, from the perspective of reducing the viscosity of the thermosetting resin composition, a range above the softening point or melting point of the thermosetting resin composition and below 200°C is preferred. Among the temperature ranges, the lower end is more preferably a temperature at least 20°C higher than the softening point or melting point, and a temperature at least 30°C higher than the softening point or melting point is even more preferred. Among the temperature ranges, the higher end is more preferably 180°C or lower, and 150°C or lower is even more preferred. If the temperature is above the melting point or softening point of the thermosetting resin composition, the viscosity is kept low so that it does not cause voids or unfilled areas, and if the temperature is below 200°C, the thermosetting resin composition hardens, so there is no concern that internal voids or surface voids cannot be sufficiently removed.

[0055] The process of placing in a molding container is shown in FIG. 3, and a container (1) containing an insulating substrate equipped with a plurality of semiconductor elements loaded with a thermosetting resin composition (6) is placed into a molding container (7).

[0056] It is preferable that the melting process be carried out in an atmosphere of atmospheric pressure or pressurized conditions. By carrying out the melting process in an atmospheric pressure or pressurized condition, the wettability of the insulating substrate equipped with multiple semiconductor devices and the thermosetting resin composition is improved, and a reduction effect on internal voids or surface voids is expected.

[0057] The heating rate during the melting process is not particularly limited, but from the perspective of shortening the molding time and suppressing the increase in viscosity of the thermosetting resin composition, 0.5°C / min to 50°C / min is preferred, 2.0°C / min to 30°C / min is more preferred, and 5.0°C / min to 20°C / min is even more preferred. If the rate is 0.5°C / min or higher, there is sufficient time to reach the set temperature, so there is no risk of the resin thickening, and if the rate is 50°C / min or lower, heat is sufficiently transferred to the resin, so there is no risk of the resin moving to the next process, the depressurization process, without being completely melted.

[0058] In addition, the heating rate in the melting process may be constant or variable during the heating process. Furthermore, after reaching a set temperature, the temperature may be maintained for a certain period of time to melt the thermosetting resin.

[0059] The time of the melting process is preferably 1 to 60 minutes after the heating of the thermosetting resin composition is started, more preferably 2 to 45 minutes, and even more preferably 4 to 30 minutes.

[0060] (3) Pressure increase / decrease process

[0061] In this process, a container containing a thermosetting resin composition is subjected to depressurization and pressurization within a molding container. In the present invention, the depressurization process refers to the process of depressurizing from atmospheric pressure to a desired level of pressure, and the pressurization process refers to the process of pressurizing from atmospheric pressure to a desired level of pressure. Meanwhile, the process of returning to atmospheric pressure from the pressurized or depressurized state is not considered, as it does not affect the quality of the power module manufactured in the manufacturing method of the present invention.

[0062] In addition, in the present invention, "atmospheric pressure" refers to a pressure in which the pressure inside the molding container is in equilibrium with the pressure in the space outside the molding container, and specifically refers to a pressure of approximately 1 atmosphere = 1013 hPa.

[0063] [Pressure Reduction Process]

[0064] The degree of pressure reduction during pressure reduction may be set to 670 Pa to 90,000 Pa. From the perspective of suppressing the occurrence of voids, it is preferable to have a pressure of 2,000 Pa to 50,000 Pa, and more preferable to have a pressure of 4,000 Pa to 40,000 Pa. If the pressure is 670 Pa or higher, there is no risk of the thermosetting resin composition overflowing from the case, and if the pressure is 90,000 Pa or lower, the degassing effect due to pressure reduction becomes sufficient.

[0065] The pressure reduction speed from atmospheric pressure to a set pressure level may be set to 100 to 60,000 Pa / sec. To reduce internal voids, the pressure reduction speed is preferably 300 to 30,000 Pa / sec, and more preferably 500 to 10,000 Pa / sec. It can be set according to the performance of the device, etc. If the pressure is 100 Pa / sec or higher, it does not take time to reach the pressure level, and since the thermosetting resin composition does not thicken, sufficient degassing can be performed. In addition, if the pressure is 60,000 Pa / sec or lower, there is no risk of the thermosetting resin composition overflowing from the case.

[0066] The depressurization rate referred to here is expressed by the following formula.

[0067] Pressure reduction rate = (Initial pressure - Pressure reduction limit) / (Time to reach pressure reduction limit)

[0068] (The unit of pressure is Pa, and the unit of time to reach is seconds.)

[0069] The temperature of the atmosphere during the vacuum process is not particularly limited and can be appropriately set depending on the type of thermosetting resin composition. It is desirable that the temperature of the thermosetting resin composition during the vacuum process be the same as the temperature during the melting process.

[0070] The depressurization process can be performed not only once but multiple times. In this case, after reaching a set depressurization level, the atmosphere may be opened to near atmospheric pressure and the set depressurization level may be reached again. In this case, the depressurization level in the first depressurization process and the depressurization level in subsequent processes may be the same or different. The depressurization process is performed one or more times, and two or more times are preferred. By performing the depressurization process multiple times, it becomes possible to effectively remove internal voids or surface voids contained in the thermosetting resin composition.

[0071] The depressurization process may maintain the state for a certain period of time after reaching a set degree of depressurization. The time for maintaining the degree of depressurization is preferably 2 seconds to 10 minutes, and more preferably 5 seconds to 5 minutes.

[0072] [Pressure Process]

[0073] In the pressurization process, the pressure level is preferably in the range of 0.1 MPa to 10 MPa from the perspective of suppressing the occurrence of voids, more preferably in the range of 0.2 MPa to 5 MPa, and even more preferably in the range of 0.2 MPa to 3 MPa. If the pressure is 0.1 MPa or higher, it is difficult for voids to remain on the surface, and the penetration of the resin into narrow parts becomes good. If the pressure is 10 MPa or lower, the resin does not flow excessively, so there is no risk of it overflowing from the case.

[0074] The pressurization rate is not particularly limited, but it is preferably 0.1 MPa / min to 1.0 MPa / min, and more preferably 0.2 MPa / min to 1.0 MPa / min.

[0075] The pressurization rate referred to here is expressed by the following formula.

[0076] Pressurization rate = (Pressurization limit pressure - Initial pressure) / (Time to reach pressurization limit pressure)

[0077] (The unit of pressure is Pa, and the unit of time to reach is seconds.)

[0078] The temperature of the atmosphere during the pressurization process is not particularly limited and can be appropriately set depending on the type of thermosetting resin composition. It is desirable that the temperature of the thermosetting resin composition during the pressurization process be the same as the temperature during the melting process.

[0079] The pressurization process can be performed not only once but multiple times. In this case, after reaching the set pressure level, the atmosphere may be opened to near atmospheric pressure, and the pressure level may be reached again. In this case, the pressure level in the first pressurization process and the pressure level in subsequent processes may be the same or different. The pressurization process is performed one or more times, and two or more times are preferred. By performing the pressurization process multiple times, it becomes possible to effectively remove internal voids or surface voids contained in the thermosetting resin composition.

[0080] The pressurization process may maintain the state for a certain period of time after reaching a set level of pressure. The time for maintaining the level of pressure is preferably 5 minutes to 4 hours, and more preferably 10 minutes to 2 hours.

[0081] The order of the depressurization and pressurization processes is not particularly limited, but by performing the pressurization process after the depressurization process, it is possible to obtain a power module with an excellent surface condition and few internal voids.

[0082] (4) Curing process

[0083] In this process, after the pressure increase / decrease process, the thermosetting resin composition is further heated and cured within the molding container.

[0084] The curing conditions at this time are not particularly limited. For example, when using a thermosetting resin composition containing an epoxy resin, the temperature may be raised to 150°C to 250°C and then cured for 1 to 12 hours. Additionally, during curing, the product may be cured under a pressure of 0.1 MPa to 10 MPa. Furthermore, the product may be removed from the molding container and further cured using a separate oven or the like. Additionally, if necessary, the air inside the molding container may be replaced with an inert gas such as nitrogen gas to perform curing.

[0085] [Thermosetting resin composition]

[0086] The thermosetting resin composition used in the method for manufacturing a power module of the present invention is a solid resin composition at 25°C. The shape of the solid thermosetting resin composition may be any shape, and may be in the form of a powder, granules, sheets, or pellets. If it is in the form of a sheet or pellet, it becomes difficult for voids to occur when the resin melts. In addition, if it is in the form of a sheet or pellet, heat is easily transferred uniformly to the resin during heating and melting, so the bubble-free properties are good during the vacuum process, and it becomes difficult for voids to remain on the surface or inside.

[0087] The thermosetting resin used in the above thermosetting resin composition may be a generally known one. Examples include epoxy resin, maleimide resin, phenolic resin, cyanate resin, polyamide resin, polyimide resin, etc. From the perspective of moldability and reliability as a packaging material, it is preferable to include epoxy resin, maleimide resin, and cyanate resin, and more preferably, to include epoxy resin.

[0088] Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, stilbene type epoxy resin, triazine backbone containing epoxy resin, fluorene backbone containing epoxy resin, triphenolalkane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aryl epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, alicyclic epoxy resin, silicone-modified epoxy resin, butadiene-modified epoxy resin, diglycidyl ether compounds of polycyclic aromatics such as polyfunctional phenols and anthracenes, and phosphorus-containing epoxy resins in which a phosphorus compound is introduced thereto. These can be used as a single type or in combination with two or more types.

[0089] As for the maleimide resin, any generally known resin having one or more maleimide groups in one molecule is not particularly limited and can be used. Examples of maleimide resins include 4,4-diphenylmethanebismaleimide, phenylmethanemaleimide, m-phenylenebismaleimide, 2,2-bis(4-(4-maleimidephenoxy)-phenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 1,6-bismaleimide-(2,2,4-trimethyl)hexane, 4,4-diphenyletherbismaleimide, 4,4-diphenylsulfonibsmaleimide, 1,3-bis(3-maleimidephenoxy)benzene, 1,3-bis(4-maleimidephenoxy)benzene, novolak-type maleimide compounds, biphenylalactyl-type maleimide, dimerate diamine-type maleimide, and the above maleimides Examples include resin prepolymers, or prepolymers of maleimide resin and amine compounds. These maleimide compounds can be used in one or a mixture of two or more types.

[0090] Among these, novolak-type maleimide compounds and biphenylalactyl-type bismaleimide compounds are preferred. By using these maleimide compounds, heat resistance tends to be further improved.

[0091] As for the cyanate resin, any generally known resin having one or more cyanato groups in one molecule may be used without particular limitation. Examples of cyanate resins include bisphenol-type cyanate esters such as 1,1-bis(4-cyanatophenyl)ethane, bis(3-methyl-4-cyanatophenyl)methane, bis(3-ethyl-4-cyanatophenyl)methane, bis(3,5-dimethyl-4-cyanatophenyl)methane, 2,2-bis(4-cyanatophenyl)propane, 2,2-bis(4-cyanatophenyl)-1,1,1,3,3,3-hexafluoropropane, diallylbisphenol A-type cyanate ester, diallylbisphenol F-type cyanate ester; Biphenyl-type cyanate esters such as 2,2'-dicianatobiphenyl, 4,4'-dicianatobiphenyl, 3,3',5,5'-tetramethyl-4,4'-dicianatobiphenyl; cyanatobenzenes such as 1,3-dicianatobenzene, 1,4-dicianatobenzene, 2-tert-butyl-1,4-dicianatobenzene, 2,4-dimethyl-1,3-dicianatobenzene, 2,5-di-tert-butyl-1,4-dicianatobenzene, tetramethyl-1,4-dicianatobenzene, 1,3,5-tricyanatobenzene; Examples include cyanatonaphthalenes such as 1,3-dicyanatonaphthalene, 1,4-dicyanatonaphthalene, 1,5-dicyanatonaphthalene, 1,6-dicyanatonaphthalene, 1,8-dicyanatonaphthalene, 2,6-dicyanatonaphthalene, 2,7-dicyanatonaphthalene, and 1,3,6-tricyanatonaphthalene; bis(4-cyanatophenyl)ether, 4,4'-(1,3-phenylenedisopropylidene)diphenylcyanate, bis(4-cyanatophenyl)thioether, and bis(4-cyanatophenyl)sulfone. These cyanate ester compounds may be used in one type or in a mixture of two or more types. Among these, preferred cyanate ester compounds are 1,1-bis(4-cyanatophenyl)ethane, diallylbisphenol A type cyanate ester, and diallylbisphenol F type cyanate ester. More preferably, they are 1,1-bis(4-cyanatophenyl)ethane and diallylbisphenol F type cyanate ester.

[0092] The above thermosetting resin composition may contain a curing agent. The type of curing agent is not particularly limited, and generally known ones may be used. Examples of curing agents when the thermosetting resin is an epoxy resin include amine-based curing agents, phenol-based curing agents, acid anhydride-based curing agents, thiol-based curing agents, etc. From the perspective of moldability and heat resistance, a phenol-based curing agent is preferred as the curing agent.

[0093] Examples of phenolic curing agents include phenol novolak resin, naphthalene ring-containing phenol resin, aryl-kill type phenol resin, triphenolalkane type phenol resin, biphenyl skeleton-containing aryl-kill type phenol resin, biphenyl type phenol resin, alicyclic phenol resin, heterocyclic phenol resin, naphthalene ring-containing phenol resin, resorcinol type phenol resin, allyl group-containing phenol resin, bisphenol A type resin, bisphenol F type resin, etc., and these can be used as one type alone or in combination of two or more types.

[0094] When a phenolic curing agent is used as a curing agent, the molar ratio of phenolic hydroxyl groups contained in the curing agent to 1 mole of epoxy groups contained in the epoxy resin is preferably 0.5 to 1.5, and more preferably 0.8 to 1.2.

[0095] The above thermosetting resin composition may contain a filler. The type of filler is not particularly limited, and generally known fillers may be used. Examples of fillers include silicas such as spherical silica, fused silica, and crystalline silica; inorganic nitrides such as silicon nitride, aluminum nitride, and boron nitride; alumina; glass fibers; and glass particles. It is preferable to include silica, as it provides excellent reinforcing effects and can suppress warping of the resulting cured product. These may be used individually or in combination of two or more types.

[0096] The average particle size and shape of the above-mentioned filler are not particularly limited, but the average particle size is preferably 0.1 to 40 μm, and more preferably 0.5 to 40 μm. Meanwhile, in the present invention, the average particle size is the mass average value D in the particle size distribution measurement by laser light diffraction. 50 It is a value obtained as (or median diameter).

[0097] In addition, regarding the high fluidity of the thermosetting resin composition used in the present invention, a combination of inorganic fillers with multiple particle size ranges may be used as the filler. In such cases, it is preferable to use a combination of spherical silica with a fine range of 0.1 to 3 μm, a medium range of 3 to 7 μm, and a coarse range of 10 to 40 μm. As a result of combining these, it is more preferable that the average particle size of the filler be in the range of 0.5 to 40 μm. For further high fluidity, it is preferable to use spherical silica with an even larger average particle size.

[0098] In addition, the above filler may be formulated with a material that has been surface-treated with a coupling agent in advance to strengthen the bonding strength with the thermosetting resin.

[0099] The content of the filler is preferably 10 to 1900 parts by mass per 100 parts by mass of the total of the thermosetting resin and its curing agent, more preferably 100 to 900 parts by mass, and particularly preferably 200 to 850 parts by mass.

[0100] The above thermosetting resin composition may contain a curing accelerator. The type of curing accelerator is not particularly limited, and generally known ones may be used.

[0101] As this curing accelerator, for example, phosphorus-based compounds such as triphenylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, triphenylphosphine·triphenylborane, tetraphenylphosphine·tetraphenylborate, tertiary amine compounds such as triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-diazabicyclo[5.4.0]undecen-7, imidazole compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, peroxides, urea compounds, salicylic acid, etc. may be used.

[0102] The content of the curing accelerator is preferably 0.2 to 10 parts by mass per 100 parts by mass of the thermosetting resin, and more preferably 0.5 to 5 parts by mass.

[0103] The above thermosetting resin composition may be formulated with a flame retardant to increase flame retardancy.

[0104] As for the flame retardant, known materials may be used without particular limitation. Examples include phosphazene compounds, silicone compounds, zinc molybdate-supported talc, zinc molybdate-supported zinc oxide, aluminum hydroxide, magnesium hydroxide, molybdenum oxide, antimony trioxide, etc., and one of these may be used alone or in combination of two or more. The amount of flame retardant is preferably 2 to 100 parts by mass per 100 parts by mass of thermosetting resin, and more preferably 3 to 50 parts by mass.

[0105] The above thermosetting resin composition may incorporate an ion trap material to prevent a decrease in reliability caused by ion impurities.

[0106] As for such ion trap materials, known materials can be used without particular limitation. For example, hydrotalcites, bismuth hydroxide compounds, rare earth oxides, etc., can be used. These may be used individually or in combination of two or more types. The amount of ion trap material is preferably 0.5 to 25 parts by mass per 100 parts by mass of thermosetting resin, and more preferably 1.5 to 15 parts by mass.

[0107] The above thermosetting resin composition may incorporate coupling agents such as silane coupling agents and titanate coupling agents for the purpose of increasing adhesion between the thermosetting resin or its curing agent and the filler, or increasing adhesion to the insulating substrate, and among these, silane coupling agents are preferred.

[0108] Examples of such coupling agents include epoxy-functional alkoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino-functional alkoxysilanes such as N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; mercapto-functional alkoxysilanes such as γ-mercaptopropyltrimethoxysilane; and amine-functional alkoxysilanes such as γ-aminopropyltrimethoxysilane and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane.

[0109] There are no specific restrictions on the amount of coupling agent used for surface treatment or the surface treatment method, and it may be carried out in accordance with commercial methods. In addition, as previously mentioned, the inorganic filler may be treated with a coupling agent in advance, or the composition may be mixed while surface treating by adding the coupling agent when mixing the filler with a resin component, such as a thermosetting resin or its curing agent.

[0110] The amount of coupling material is preferably 0.1 to 25 parts by mass per 100 parts by mass of thermosetting resin, and particularly preferably 0.5 to 20 parts by mass. If it is 0.1 parts by mass or more, sufficient adhesion effect to the substrate is obtained, and if it is 25 parts by mass or less, the viscosity is drastically reduced, so there is no risk of it causing voids.

[0111] The above thermosetting resin composition may contain a release agent. The release agent is not particularly limited and generally known ones may be used. The release agent is incorporated to enhance release properties during molding. Examples of such release agents include natural waxes such as carnauba wax and rice wax, acid wax, polyethylene wax, and synthetic waxes such as fatty acid esters; however, carnauba wax is preferred from the perspective of release properties.

[0112] The amount of release agent is preferably 0.05 to 15 parts by mass per 100 parts by mass of thermosetting resin, and more preferably 0.1 to 10 parts by mass. If the amount is 0.05 parts by mass or more, there is no concern that sufficient release properties will not be obtained or that an overload will occur during melt mixing in manufacturing, and if it is 15 parts by mass or less, there is no concern that poor penetration or poor adhesion will occur.

[0113] The thermosetting resin composition may contain a coloring agent. Examples of known coloring agents include carbon black, organic dyes, organic pigments, titanium oxide, Bengala, etc. Carbon black is preferred in terms of dispersibility in the thermosetting resin.

[0114] The amount of coloring agent is preferably 0.01 to 10 parts by mass per 100 parts by mass of thermosetting resin, and more preferably 0.1 to 5 parts by mass.

[0115] A thermosetting resin composition may be formulated with an antifoaming agent to suppress foaming of the resin during a melting process or a pressure increase / decrease process.

[0116] Examples of such defoaming agents include known defoaming agents such as polyethers, polyesters, higher alcohols, higher alcohol derivatives, fatty acid derivatives, rapid soaps, silicone oils, polysiloxanes, waxes, and mineral oils.

[0117] The amount of defoaming agent is preferably 0.01 to 10 parts by mass per 100 parts by mass of thermosetting resin, and more preferably 0.01 to 5 parts by mass.

[0118] [Method for preparing a thermosetting resin composition]

[0119] As a method for preparing the thermosetting resin composition used in the present invention, conventionally known methods may be appropriately utilized. Examples of preparation methods include hot rolls, kneaders, extruders, etc. The obtained thermosetting resin composition may be ground into a powder by crushing, or into a tablet or granule form by compressing it after grinding, or into a sheet form using a press device or a T-die. From the perspective of reducing voids during molding, a pellet or sheet form is preferred.

[0120] The thermosetting resin composition obtained in this way is preferably 1 to 20 mm thick and more preferably 2 to 10 mm thick if it is in the form of a sheet. In addition, if it is in the form of a pellet, it is preferably 10 to 100 mm thick and more preferably 20 to 80 mm thick, and it is preferably 0.5 to 50 mm thick and more preferably 1 to 40 mm thick if it is in the form of a length.

[0121] [Physical properties of thermosetting resin compositions]

[0122] The viscosity of the thermosetting resin composition at 120°C is preferably 0.01 Pa·s to 500 Pa·s, more preferably 0.1 Pa·s to 300 Pa·s, and particularly preferably 0.1 Pa·s to 100 Pa·s. In the present invention, the viscosity of the thermosetting resin composition at 120°C refers to a value measured using a rheometer as described in JIS K 7244-10:2005. For example, the HR-2 (manufactured by TA Instruments) is used as the rheometer.

[0123] The time for the viscosity of the thermosetting resin composition at 120°C to increase to 10 times its initial value is preferably 5 to 60 minutes, and more preferably 10 to 60 minutes. If it is 5 minutes or longer, the fillability does not deteriorate, and there is no risk of internal voids or surface voids occurring.

[0124] The glass transition temperature of the thermosetting resin composition when cured is preferably 120 to 250°C, and more preferably 150 to 250°C. By having the glass transition temperature within the above range, the heat resistance reliability of the power module is improved.

[0125] In the present invention, the glass transition temperature (Tg) refers to a value obtained by the TMA method. For the measurement by the TMA method, a cured product obtained by curing a thermosetting resin composition is processed into a 5×5×15 mm test specimen, and then the test specimens are set in a thermal expansion meter TMA8140C (manufactured by Rigaku Co., Ltd.). Then, the heating program is set to a heating rate of 5°C / min, and a constant load of 19.6 mN is applied, and the dimensional change of the test specimen is measured between 25°C and 300°C. The relationship between this dimensional change and temperature is plotted on a graph (an example of the graph is shown in FIG. 1). From the graph of dimensional change and temperature obtained in this way, the glass transition temperature can be determined by the method for determining the glass transition temperature described below.

[0126] As shown in FIG. 1, any two temperature points T1 and T2 are defined as the tangents to the dimensional change-temperature curve obtained at temperatures below the inflection point, and any two temperature points T1' and T2' are defined as the same tangents obtained at temperatures above the inflection point. The dimensional changes at T1 and T2 are defined as D1 and D2, respectively, and the straight line connecting points (T1, D1) and (T2, D2) is defined as the glass transition temperature (Tg). The intersection point of the straight line connecting points (T1', D1') and (T2', D2') is defined as the dimensional changes at T1' and T2', respectively.

[0127] It is preferable that the average coefficient of thermal expansion at 40°C to 80°C when the thermosetting resin composition is cured be 3 ppm / °C to 30 ppm / °C, and more preferable that it be 5 ppm / °C to 25 ppm / °C. If the average coefficient of thermal expansion is within the above range, the difference in the coefficient of thermal expansion with the semiconductor device or insulating substrate is reduced, and it becomes possible to suppress the occurrence of warping after encapsulation. The average coefficient of thermal expansion in the present invention is the average value of the coefficient of linear expansion calculated from the measurement results in the temperature range from 40°C to 80°C by performing thermomechanical analysis of the cured product under the same conditions as the glass transition temperature measurement above.

[0128] The thermosetting resin composition preferably has a bending modulus of 5 GPa to 35 GPa in its cured product at 25°C, and more preferably 10 GPa to 30 GPa. If the bending modulus of 5 GPa or higher at 25°C is present, delamination between the insulating substrate and the thermosetting resin composition can be suppressed during reliability tests such as heat cycle tests or high-temperature storage tests, and defects in the power module can be suppressed. If the modulus of 35 GPa or lower at 25°C is present, there is a tendency to effectively suppress stress caused by the cured product of the thermosetting resin composition itself.

[0129] Meanwhile, the bending modulus at 25°C can be measured by producing a hardened product in accordance with JIS K 6911:2006.

[0130] [Power Module]

[0131] The power module of the present invention may comprise an insulating substrate to which a power semiconductor device is bonded, and a cured product of a thermosetting resin composition that encapsulates the insulating substrate.

[0132] Specific examples of power semiconductor devices include semiconductor devices (power semiconductor chips) such as IGBTs (insulated gate bipolar transistors), diodes, Si-based MOSFETs (metal oxide semiconductor field-effect transistors), SiC-based MOSFETs, and GaN-based FETs (gallium nitride field-effect transistors).

[0133] In the present invention, an insulating substrate refers to a substrate having a copper plate or a metal pattern, such as gold plating, silver plating, or nickel plating, applied to one or both sides of an insulating material for the purpose of increasing heat dissipation, and having insulating properties in the thickness direction of the substrate. Specific examples of the insulating material include ceramics such as alumina or silicon nitride. In addition, the same as described above may be used as the cured product of the thermosetting resin composition.

[0134] A power module manufactured by the manufacturing method of the present invention is a power module with excellent reliability, free from voids or cracks. Specifically, in a cured product of a thermosetting resin composition in which the power module is encapsulated, the number of internal voids with a diameter of 100 μm or more in the cured product is 10 / cm² 3 It is characterized by being less than or equal to 5 pieces / cm 3 Less than, more preferably 2 pieces / cm 3 It is as follows.

[0135] [Example]

[0136] The present invention will be explained in more detail below with reference to examples and comparative examples. The present invention is not limited to the following examples.

[0137] <Examples 1–19 and Comparative Examples 1–4>

[0138] [Preparation of thermosetting resin composition]

[0139] A thermosetting resin composition was obtained by mixing in the amounts (parts by mass) listed in Table 1. The details of each component are as follows.

[0140] Epoxy Resin 1: Biphenyl-type epoxy resin (YX-4000K: Manufactured by Mitsubishi Chemical)

[0141] Epoxy Resin 2: Triphenolmethane-type epoxy resin (EPPN-501H: Manufactured by Nippon Hwagyak Co.)

[0142] Curing agent: Phenol novolak resin (BRG-555: manufactured by Aika Industrial Co.)

[0143] Curing accelerator: Urea-type catalyst (U-CAT3513N: acid aprosase)

[0144] Coupling agent: γ-glycidoxypropyltrimethoxysilane (Product name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0145] Fused silica: Fused spherical silica with an average particle size of 14 μm (manufactured by Tatsumori Co.)

[0146] Colorant: Carbon black (Mitsubishi Chemical Co., Ltd.)

[0147] [Measurement of Softening Point]

[0148] The softening point of the prepared composition was measured according to JIS K 7234 (1986), and the results were listed in Table 1.

[0149] [Measurement of Viscosity]

[0150] The prepared thermosetting resin composition was measured using a rheometer (plate diameter 25 mm, measurement frequency 1 Hz) set to 120°C, and the values ​​were listed in Table 1. In addition, the time to reach 10 times the initial viscosity was listed in Table 1.

[0151] [Preparation of Cured Material Samples]

[0152] A thermosetting resin composition shown in Table 1 was heat-cured at 120°C for 30 minutes and additionally at 180°C for 1 hour to obtain a cured product.

[0153] [Measurement of Glass Transition Temperature]

[0154] A cured product obtained by curing a thermosetting resin composition was processed into a 5×5×15 mm test specimen, and the test specimens were set in a thermal expansion meter TMA8140C (manufactured by Rigaku Co., Ltd.). Then, the heating program was set to a heating rate of 5°C / min and a constant load of 19.6 mN was applied, and the dimensional change of the test specimens was measured between 25°C and 300°C. The relationship between this dimensional change and temperature was plotted on a graph (an example of the graph is shown in Fig. 1). From the graph of dimensional change and temperature obtained in this way, the glass transition temperatures in the examples and comparative examples were determined by the method for determining the glass transition temperature described below.

[0155] As shown in FIG. 1, two arbitrary temperature points T1 and T2 are defined as the tangents to the dimensional change-temperature curve obtained at temperatures below the inflection point, and two arbitrary temperature points T1' and T2' are defined as the same tangents obtained at temperatures above the inflection point. The dimensional changes at T1 and T2 are defined as D1 and D2, respectively, and the straight line connecting points (T1, D1) and (T2, D2) is defined as D1' and D2', respectively, and the intersection point of the straight line connecting points (T1', D1') and (T2', D2') is defined as the glass transition temperature (Tg).

[0156] [Method for Determining Coefficient of Linear Expansion (CTE1)]

[0157] Thermomechanical analysis of the cured product was performed under the same conditions as the glass transition temperature measurement above, and the coefficient of linear expansion was calculated from the measurement results in the temperature range from 40°C to 80°C and set as CTE1.

[0158] [Measurement of Bending Modulus]

[0159] The bending modulus was measured using the above-mentioned hardened material in accordance with JIS K 6911:2006.

[0160]

[0161] (Example 1)

[0162] A container was prepared by die-bonding a Si chip with solder and wire-bonding it with aluminum wire on a 110 mm × 90 mm DBC (Direct Bond Copper) insulating substrate made of nickel-plated copper and insulating ceramic, with a polyphenylene sulfide (PPS) resin rim attached. The thermosetting resin composition listed in Table 1 was placed inside the container so that it covered 95% of the packaging area. The container containing the thermosetting resin composition was placed inside a pressure oven. Then, the temperature inside the pressure oven was increased to 100°C at a rate of 10°C / min to melt the composition. After reaching 100°C, the pressure inside the pressure oven was reduced to 50,000 Pa at a rate of 300 Pa / sec, and after reaching 50,000 Pa, it was maintained for 1 minute. Subsequently, the pressure inside the pressurized oven was set to atmospheric pressure, and pressure was applied from 100°C to 1.0 MPa at a rate of 0.1 MPa / min. After reaching 1.0 MPa, the pressure was maintained for 10 minutes. Then, while maintaining the pressure inside the pressurized oven at 1.0 MPa, the temperature was raised to 150°C at a rate of 10°C / min. After reaching 150°C, the temperature was maintained for 2 hours to heat-cur the thermosetting resin composition, thereby obtaining a power module.

[0163] (Example 2)

[0164] A power module was obtained in the same manner as in Example 1, except that a thermosetting resin composition was placed inside a container such that the area of ​​the packaging area was 30%.

[0165] (Example 3)

[0166] A power module was obtained in the same manner as in Example 1, except that the heating rate when raising the temperature inside the pressure oven to 100℃ was 0.5℃ / min and the thermosetting resin composition was melted.

[0167] (Example 4)

[0168] A power module was obtained in the same manner as in Example 1, except that the heating rate when raising the temperature inside the pressure oven to 100℃ was 30℃ / min and the thermosetting resin composition was melted.

[0169] (Example 5)

[0170] A power module was obtained in the same manner as in Example 1, except that the inside of the pressurized oven was heated to 180°C and the thermosetting resin composition was melted.

[0171] (Example 6)

[0172] A power module was obtained in the same manner as in Example 1, except that the pressure inside the pressurized oven was reduced to 2,000 Pa.

[0173] (Example 7)

[0174] A power module was obtained in the same manner as in Example 1, except that the pressure inside the pressurized oven was reduced to 100 Pa / sec.

[0175] (Example 8)

[0176] A power module was obtained in the same manner as in Example 1, except that the pressure inside the pressurized oven was reduced to 60,000 Pa / sec.

[0177] (Example 9)

[0178] A power module was obtained in the same manner as in Example 1, except that the inside of the pressurized oven was pressurized to 0.2 MPa.

[0179] (Example 10)

[0180] A power module was obtained in the same manner as in Example 1, except that the inside of the pressurized oven was pressurized to 5 MPa.

[0181] (Example 11)

[0182] A power module was obtained in the same manner as in Example 1, except that a thermosetting resin composition was placed inside a container so as to occupy 20% of the bag area.

[0183] (Example 12)

[0184] A power module was obtained in the same manner as in Example 1, except that the heating rate when raising the temperature inside the pressure oven to 100℃ was 0.3℃ / min and the thermosetting resin composition was melted.

[0185] (Example 13)

[0186] A power module was obtained in the same manner as in Example 1, except that the heating rate when raising the temperature inside the pressure oven to 100℃ was 60℃ / min and the thermosetting resin composition was melted.

[0187] (Example 14)

[0188] A power module was obtained in the same manner as in Example 1, except that the inside of the pressurized oven was heated to 60°C and the thermosetting resin composition was melted.

[0189] (Example 15)

[0190] A power module was obtained in the same manner as in Example 1, except that the inside of the pressurized oven was heated to 220°C and the thermosetting resin composition was melted.

[0191] (Example 16)

[0192] A power module was obtained in the same manner as in Example 1, except that the pressure inside the pressurized oven was reduced to 300 Pa.

[0193] (Example 17)

[0194] A power module was obtained in the same manner as in Example 1, except that the pressure inside the pressurized oven was reduced to 50 Pa / sec.

[0195] (Example 18)

[0196] A power module was obtained in the same manner as in Example 1, except that the pressure inside the pressurized oven was reduced to 75,000 Pa / sec.

[0197] (Example 19)

[0198] A power module was obtained in the same manner as in Example 1, except that the inside of the pressurized oven was pressurized to 0.06 MPa.

[0199] (Comparative Example 1)

[0200] A power module was obtained in the same manner as in Example 1, except that the process of melting the thermosetting resin composition was not included and the inside of the pressure oven was not heated.

[0201] (Comparative Example 2)

[0202] A power module was obtained in the same manner as in Example 1, except that it did not include a process of depressurizing the inside of the pressurized oven.

[0203] (Comparative Example 3)

[0204] A power module was obtained in the same manner as Example 1, except that the process of pressurizing the inside of the pressurized oven was not included.

[0205] (Comparative Example 4)

[0206] A power module was obtained in the same manner as in Example 1, except that the process of heating the inside of a pressure oven and curing a thermosetting resin composition was not included.

[0207] [Evaluation of Surface Voids]

[0208] For the power modules obtained in Examples 1 to 19 and Comparative Examples 1 to 4, the presence or absence of surface voids was confirmed using an optical microscope. The number of surface voids with a diameter of 100 μm or more was 2 / cm² 3 Below ◎, the number of surface voids is 3~5 / cm² 3 ○, the number of surface voids is 6~10 / cm 3 Δ, the number of surface voids is 10 / cm² 3 Those exceeding were marked × and recorded in Table 2.

[0209] [Inner Void's Evaluation]

[0210] For the power modules obtained in Examples 1 to 19 and Comparative Examples 1 to 4, the presence or absence of internal voids was confirmed using an ultrasonic probe. The number of internal voids with a diameter of 100 μm or more was 2 / cm² 3 ◎ for the following, the number of internal voids is 3~5 / cm² 3 ○, the number of internal voids is 6~10 / cm3 Δ, the number of internal voids is 10 / cm² 3 Those exceeding were marked × and recorded in Table 2.

[0211] [Heat Cycle Test (Heat Resistance)]

[0212] The power modules obtained in Examples 1 to 19 and Comparative Examples 1 to 4 were subjected to a heat cycle test (maintaining at -65°C for 30 minutes and maintaining at 150°C for 30 minutes, repeated 1,000 times), and the delamination state between the thermosetting resin composition and the DBC insulating substrate after the heat cycle test was confirmed using an ultrasonic probe. Of the total 5 molded products, those showing delamination were counted.

[0213] [Moisture Reliability Test]

[0214] The power modules obtained in Examples 1 to 19 and Comparative Examples 1 to 4 were subjected to a moisture reliability test (exposure for 48 hours under saturated steam at 121°C and 2.03 × 10⁵ Pa in a pressure cooker), and the delamination state between the thermosetting resin composition and the DBC insulating substrate after the moisture reliability test was confirmed using an ultrasonic probe. Of the total 5 molded products, those showing delamination were counted.

[0215]

[0216] From these results, when comparing the examples and comparative examples, it can be seen that if any of the processes of melting, depressurization, pressurization, or curing is missing, voids or delamination from the insulating substrate are observed, and a power module with excellent reliability cannot be obtained. In addition, although the power module of the present invention could be obtained in Examples 1 to 10, in which the encapsulation area, heating rate, heating melting temperature, pressure during depressurization, depressurization rate, and pressure during pressurization were set within a desirable range, and in Examples 11 to 19, in which any one of these parameters was set outside the desirable range, it can be seen that the Examples 1 to 10, in which each parameter was set within a desirable range, yielded better results.

[0217] Meanwhile, the present invention is not limited to the above embodiments. The above embodiments are examples, and any configuration that is substantially identical to the technical concept described in the claims of the present invention and exhibits the same functional effects is included within the technical scope of the present invention. Explanation of the symbols

[0218] 1: A container housing an insulating substrate equipped with multiple semiconductor devices, 2: Bonding wire, 3: Power semiconductor device, 4: Insulating substrate, 5: Container, 6: Thermosetting resin composition, 7: Molded container

Claims

Claim 1 A method for manufacturing a power module, comprising the following steps (1) to (4): (1) a placement process in which a solid thermosetting resin composition at 25°C is placed in a container containing an insulating substrate on which a plurality of semiconductor elements are mounted; (2) a melting process in which the container in which the thermosetting resin composition is placed is placed in a molding device capable of heating, pressurizing, and depressurizing, and the thermosetting resin composition is heated and melted; (3) a pressure increase / decrease process in which the inside of the molding device is depressurized and pressurized at least once; (4) a curing process in which the inside of the molding device is heated to cure the thermosetting resin composition, wherein in the pressure decrease process of the pressure increase / decrease process (3), the pressure is reduced to 670 Pa to 90,000 Pa. Claim 2 A method for manufacturing a power module according to claim 1, wherein in the melting process (2), the heating temperature is set higher than the melting point or softening point of the thermosetting resin composition and also lower than 200°C. Claim 3 A method for manufacturing a power module according to claim 1, characterized in that, in the melting process (2), the heating rate during heating is 0.5℃ / min to 50℃ / min. Claim 4 A method for manufacturing a power module according to claim 2, characterized in that, in the melting process (2), the heating rate during heating is 0.5℃ / min to 50℃ / min. Claim 5 A method for manufacturing a power module according to claim 1, characterized in that, in the above-mentioned pressure reduction process (3), the pressure reduction and / or pressure increase are repeated two or more times. Claim 6 A method for manufacturing a power module according to claim 2, characterized in that, in the above-mentioned pressure reduction process (3), the pressure reduction and / or pressure increase are repeated two or more times. Claim 7 A method for manufacturing a power module according to claim 3, characterized in that, in the above-mentioned pressure reduction process (3), the pressure reduction and / or pressure increase are repeated two or more times. Claim 8 A method for manufacturing a power module according to claim 4, characterized in that, in the above-mentioned pressure reduction process (3), the pressure reduction and / or pressure increase are repeated two or more times. Claim 9 A method for manufacturing a power module according to claim 1, characterized in that, in the pressurization process of the above-mentioned pressurization / pressurization process (3), the pressurization is applied to a pressure of 0.1 MPa to 10 MPa. Claim 10 A method for manufacturing a power module according to claim 2, characterized in that, in the pressurization process of the above-mentioned pressurization / pressurization process (3), the pressurization is applied to a pressure of 0.1 MPa to 10 MPa. Claim 11 A method for manufacturing a power module according to claim 3, characterized in that, in the pressurization process of the above-mentioned pressurization / pressurization process (3), the pressurization is applied to a pressure of 0.1 MPa to 10 MPa. Claim 12 A method for manufacturing a power module according to claim 4, characterized in that, in the pressurization process of the above-mentioned pressurization / reduction process (3), the pressurization is applied to a pressure of 0.1 MPa to 10 MPa. Claim 13 delete Claim 14 delete Claim 15 A method for manufacturing a power module according to claim 1, characterized in that, in the pressure reduction process of the pressure increase / decrease process (3), the pressure reduction speed from atmospheric pressure to a set pressure level is 100 to 60,000 Pa / sec. Claim 16 A method for manufacturing a power module according to claim 2, wherein in the pressure reduction process of the pressure increase / decrease process (3) above, the pressure reduction speed from atmospheric pressure to a set pressure level is 100 to 60,000 Pa / sec. Claim 17 A method for manufacturing a power module, characterized in that, in any one of claims 1 to 12, 15 and 16, the thermosetting resin composition is arranged in the batching process (1) such that the area of ​​the packaging area is 30% to 95%. Claim 18 delete

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