Power module and method for manufacturing the same

Abstract

The present invention provides a method for manufacturing a power module capable of shortening the manufacturing time of the power module. The method comprises: a subassembly configuration step, in which a subassembly having a first electrode, a semiconductor element, and a second electrode is placed on a heat sink via a bonding material; and a transfer molding step, in which, after the subassembly configuration step, a thermoplastic resin is injected into a region surrounded by a heat sink and a forming mold in a state where the first electrode, the semiconductor element, and the inner part of the second electrode are configured in the region, and in the transfer molding step, the subassembly is bonded to the heat sink via the bonding material by the resin.

Description

Technical Field

[0001] The invention relates to a power module and a method for manufacturing the same. Background Art

[0002] Conventionally, a power module is known in which a resin portion is provided around a subassembly in which a first substrate, a semiconductor substrate, and a second substrate are stacked in sequence, and the first substrate is bonded to a heat sink via a bonding material. The power module is manufactured by a power module manufacturing method including a transfer molding process and a heat sink bonding process performed after the transfer molding process. In the transfer molding process, a thermoplastic resin is injected into the inner side of the forming mold while the subassembly is arranged on the inner side of the forming mold. In the heat sink process, the first substrate is bonded to the heat sink via a bonding material (for example, refer to Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6328298 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] However, a curing step is required after the transfer molding step and after the heat sink bonding step, respectively, which increases the time required to manufacture the power module.

[0008] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a power module and a method for manufacturing the power module that can shorten the manufacturing time of the power module.

[0009] Technical means for solving technical problems

[0010] The power module involved in the present invention includes: a subassembly having a first electrode, a semiconductor element bonded to the first electrode, and a second electrode bonded to the semiconductor element; a heat sink, which is bonded to the subassembly via a bonding material; and a resin portion, which is integrally formed with the first electrode, the semiconductor element, the portion of the second electrode bonded to the semiconductor element, i.e., the inner portion of the second electrode, and the heat sink.

[0011] The manufacturing method of the power module involved in the present invention includes: a subassembly configuration step, in which a subassembly having a first electrode, a semiconductor element bonded to the first electrode, and a second electrode bonded to the semiconductor element is placed on a heat sink via a bonding material; and a transfer molding step, in which, after the subassembly configuration step, in a state where the first electrode, the semiconductor element, and a portion of the second electrode bonded to the semiconductor element are configured in an area surrounded by a heat sink and a forming mold, i.e., an inner portion of the second electrode, a thermoplastic resin is injected into the area, and in the transfer molding step, the subassembly is bonded to the heat sink via the bonding material by the resin.

[0012] Effects of the Invention

[0013] According to the power module and the manufacturing method thereof according to the present invention, the manufacturing time of the power module can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a circuit diagram showing a main part of a power conversion device including a power module according to Embodiment 1 of the present invention.

[0015] Figure 2 This is a cross-sectional view showing a main part of a power module according to Embodiment 1 of the present invention.

[0016] Figure 3 It is shown Figure 2 A cross-sectional view of a subassembly.

[0017] Figure 4 It shows the manufacturing Figure 2 Flowchart of the steps of power module.

[0018] Figure 5 It is shown Figure 2 A cross-sectional view of a state in which a subassembly, a bonding material, and a heat sink are arranged inside a forming mold.

[0019] Figure 6 It is shown Figure 2 A cross-sectional view of a radiator in a state where a water jacket is coupled thereto.

[0020] Figure 7 It is shown Figure 6 A cross-sectional view of a modified example of a power module.

[0021] Figure 8 It is shown Figure 7 A top view of a modified example of the frame.

[0022] Fig. 9 This is a cross-sectional view showing a main part of a power module manufactured by a power module manufacturing method according to Embodiment 2 of the present invention.

[0023] Fig.10 This is a cross-sectional view showing a main part of a power module manufactured by a power module manufacturing method according to Embodiment 3 of the present invention.

[0024] Fig.11 It is shown Fig.10 A cross-sectional view of a state in which a subassembly, a bonding material, and a heat sink are arranged inside a forming mold. DETAILED DESCRIPTION

[0025] Implementation method 1.

[0026] Figure 1 1 is a circuit diagram showing the main parts of a power conversion device having a power module according to Embodiment 1 of the present invention. The power conversion device has a switching circuit for controlling power. Examples of the power conversion device include an inverter for driving a motor mounted on an electric vehicle, a buck converter for converting a voltage from a high voltage to a low voltage, and a charger connected to an external power supply device to charge a vehicle battery.

[0027] Figure 1 , an inverter for driving a motor is shown in FIG. The inverter for driving a motor has a switching circuit for a U phase, a switching circuit for a V phase, and a switching circuit for a W phase. The switching circuit for the U phase has a U phase upper arm 101 and a U phase lower arm 102. The switching circuit for the V phase has a V phase upper arm 103 and a V phase lower arm 104. The switching circuit for the W phase has a W phase upper arm 105 and a W phase lower arm 106.

[0028] The U-phase upper arm 101, the U-phase lower arm 102, the V-phase upper arm 103, the V-phase lower arm 104, the W-phase upper arm 105, and the W-phase lower arm 106 are respectively composed of semiconductor elements. As semiconductor elements, for example, MOS-FET (Metal-Oxide-Semiconductor Field-Effect), IGBT (Insulated Gate Bipolar Transistor) and diodes can be cited. Silicon, silicon nitride and gallium nitride are used as substrates of semiconductor elements.

[0029] In order to increase the capacity of a power conversion device, a plurality of semiconductor elements are connected in parallel in the power conversion device. In addition, due to the limitation of the manufacturing yield of the substrate of the semiconductor element, a plurality of semiconductor elements with a small outer size are used in the power conversion device.

[0030] Figure 2 1 is a cross-sectional view showing a main part of a power module according to Embodiment 1 of the present invention. The power module 1 includes a subassembly 11 , a heat sink 12 , a bonding material 13 , and a resin portion 14 .

[0031] Figure 3 It is shown Figure 2 1 is a cross-sectional view of a subassembly 11. The subassembly 11 includes a first electrode 111, a semiconductor element 112, a second electrode 113, and a third electrode 114. In addition, the subassembly 11 includes a first bonding material 115 and a second bonding material 116.

[0032] The semiconductor element 112 is formed in a flat plate shape. The semiconductor element 112 is bonded to the first electrode 111 via a first bonding material 115 in a state where one surface of the semiconductor element 112 faces the first electrode 111. As the first bonding material 115, for example, solder can be cited. The semiconductor element 112 is die-bonded to the first electrode 111.

[0033] In a state where the other surface of the semiconductor element 112 faces the second electrode 113, the semiconductor element 112 is bonded to the second electrode 113 via the second bonding material 116. As the second bonding material 116, for example, solder can be cited. In addition, the semiconductor element 112 and the second electrode 113 can also be bonded to each other by wire bonding. The third electrode 114 is bonded to the first electrode 111 using solder.

[0034] like Figure 2 As shown, the resin portion 14 covers the first electrode 111, the semiconductor element 112, and the portion of the second electrode 113 bonded to the semiconductor element 112. The portion of the second electrode 113 bonded to the semiconductor element 112 is defined as the second electrode inner portion 113A. Therefore, the second electrode inner portion 113A is covered by the resin portion 14. The portion of the second electrode 113 disposed outside the resin portion 14 is defined as the second electrode outer portion 113B. The second electrode outer portion 113B extends from the side surface of the resin portion 14 along the semiconductor element 112. The second electrode outer portion 113B extends from the side surface of the resin portion 14 in a direction perpendicular to the side surface of the resin portion 14.

[0035] The resin portion 14 covers one end of the third electrode 114. The other end of the third electrode 114 is arranged outside the resin portion 14. The other end of the third electrode 114 extends from the side surface of the resin portion 14 along the semiconductor element 112. The other end of the third electrode 114 extends from the side surface of the resin portion 14 in a direction perpendicular to the side surface of the resin portion 14.

[0036] The subassembly 11 is bonded to the heat sink 12 via a bonding material. The heat sink 12 includes: a flat plate portion 121 on which the subassembly 11 is placed via a bonding material 13; and a plurality of heat dissipation fins 122 provided on the flat plate portion 121. The flat plate portion 121 is formed with a first surface 123 and a second surface 124 facing the opposite side relative to the first surface 123. The subassembly 11 is placed on the first surface 123 via the bonding material 13. The heat dissipation fins 122 are provided on the second surface 124.

[0037] In this example, a structure in which a subassembly 11 having one semiconductor element 112 is placed on one heat sink 12 is described. In addition, a structure in which a subassembly 11 having a plurality of semiconductor elements 112 is placed on one heat sink 12 may be adopted. Specifically, a structure in which a subassembly 11 having two semiconductor elements 112 is placed on one heat sink 12, or a structure in which a subassembly 11 having six semiconductor elements 112 is placed on one heat sink 12 may be adopted.

[0038] The first electrode 111 is bonded to the flat plate portion 121 of the heat sink 12 via a bonding material 13. The bonding material 13 has insulating properties. The bonding material 13 is a resin composition in which a base material is impregnated with a thermosetting resin, and is a resin composition that is semi-cured by drying. Examples of the base material of the bonding material 13 include fibrous reinforcement materials and ceramic sintered bodies. Examples of the thermosetting resin impregnated in the base material of the bonding material 13 include epoxy resins. The bonding material 13 is in the shape of a film or a sheet. Semi-curing refers to the state before the thermosetting resin is completely cured. In this example, a structure using an adhesive sheet as the bonding material 13 is described.

[0039] The resin portion 14 is integrally formed with the first electrode 111, the semiconductor element 112, the second electrode inner portion 113A, and the heat sink 12. The resin portion 14 is integrally formed with the first surface 123 and the side surface of the heat sink 12. The resin portion 14 covers a portion of the heat sink 12.

[0040] Next, a method for manufacturing the power module 1 will be described. Figure 4 It shows the manufacturing Figure 2 Flowchart of the steps of the power module 1. First, in step S1, a subassembly manufacturing process is performed. In the subassembly manufacturing process, the semiconductor element 112 is bonded to the first electrode 111, the second electrode 113 is bonded to the semiconductor element 112, and the third electrode 114 is bonded to the first electrode 111. In this way, the subassembly 11 is manufactured.

[0041] Then, in step S2, a subassembly configuration process is performed. Figure 5 It is shown Figure 2A cross-sectional view of a state in which the subassembly 11, the bonding material 13, and the heat sink 12 are arranged on the inner side of the forming mold. In the subassembly arrangement process, the heat sink 12 is arranged in the lower mold 21 of the forming mold 2, and the first sealing member 22 is arranged between the peripheral portion of the second surface 124 of the flat plate portion 121 of the heat sink 12 and the lower mold 21 so that the resin does not flow around the heat dissipation fins 122. As a result, the peripheral portion of the second surface 124 and the forming mold 2 are sealed. In addition, in the subassembly arrangement process, the subassembly 11 is placed on the first surface 123 of the flat plate portion 121 of the heat sink 12 via the bonding material 13. At this time, the first electrode 111 overlaps with the heat sink 12 via the bonding material 13.

[0042] In the subassembly placement step, the plurality of first pins 23 press the first electrode 111 toward the heat sink 12 . Thus, the first electrode 111 is positioned relative to the heat sink 12 , and airtightness is ensured by the first sealing member 22 between the heat sink 12 and the lower mold 21 .

[0043] Furthermore, in the subassembly configuration process, the second pin 24 abuts against at least two or more pin abutment portions formed in the bonding material 13. Thus, the bonding material 13 is positioned relative to the heat sink 12. At this time, the two or more pin abutment portions in the bonding material 13 become two or more side surfaces formed in the bonding material 13. The side surface of the bonding material 13 that becomes the pin abutment portion may be, for example, a side surface of the bonding material 13 that is formed by chamfering a corner portion in the bonding material 13 before processing that is formed into a quadrilateral shape. The bonding material 13 before processing that is formed into a quadrilateral shape is a bonding material 13 that is a quadrilateral shape when the bonding material 13 is observed in a direction perpendicular to the upper surface of the bonding material 13. In addition, the two or more pin abutment portions in the bonding material 13 may be two or more holes formed in the bonding material 13.

[0044] Furthermore, in the subassembly placement step, the upper mold 25 is placed on the lower mold 21. At this time, a portion of the second electrode 113 and a portion of the third electrode 114 are placed outside the molding die 2 through the gap between the lower mold 21 and the upper mold 25. Thus, the first electrode 111, the semiconductor element 112, and the second electrode inner portion 113A are placed in the area surrounded by the heat sink 12 and the molding die 2.

[0045] Afterwards, if Figure 4As shown, in step S3, a transfer molding process is performed. In the transfer molding process, the molding die 2 is heated until the temperature of the molding die 2 reaches a set temperature. In addition, in the transfer molding process, the thermoplastic resin is pressurized until the thermoplastic resin reaches a set pressure. In a state where the temperature of the molding die 2 reaches the set temperature and the thermoplastic resin reaches the set pressure, the thermoplastic resin is injected into the inner side of the molding die 2 through the gate 26 of the molding die 2.

[0046] In the transfer molding process, the first electrode 111 is pressed against the heat sink 12 via the bonding material 13 by the pressure of the resin injected into the inner side of the molding die 2. As a result, the bubbles contained in the bonding material 13 are removed from the bonding material 13. In addition, in the transfer molding process, the first electrode 111 and the heat sink 12 are bonded via the bonding material 13 by the heat of the resin injected into the inner side of the molding die 2. By removing the bubbles contained in the bonding material 13 from the bonding material 13, the heat dissipation and insulation properties of the bonding material 13 are improved. The resin portion 14 is integrally formed with the first electrode 111, the semiconductor element 112, the second electrode inner portion 113A, and the heat sink 12 through the transfer molding process.

[0047] Then, in step S4, a water jacket bonding process is performed. Figure 6 It is shown Figure 2 FIG. 1 is a cross-sectional view showing a state where the water jacket is joined to the heat sink 12 . In the water jacket joining step, the water jacket 15 is joined to the heat sink 12 . The water jacket 15 is included in the power module 1 .

[0048] By the water jacket joining process, a water path for the refrigerant used for forced water cooling to flow is formed around the heat dissipation fins 122 of the radiator 12. As a method for joining the radiator 12 and the water jacket 15, welding and friction stir joining can be cited. In addition, a second sealing member 16 is arranged between the radiator 12 and the water jacket 15. As a result, the radiator 12 and the water jacket 15 are sealed. The second sealing member 16 is included in the power module 1. As the second sealing member 16, an O-ring or a liquid filler can be cited. As described above, the steps of manufacturing the power module 1 are completed.

[0049] Figure 7 It is shown Figure 6 sectional view of a modified example of the power module 1. Figure 6 In FIG. 1 , a structure in which a radiator 12 is connected to a water jacket 15 is shown, but Figure 7As shown in the figure, a structure in which one water jacket 15 is joined to two radiators 12 may also be adopted. In this case, the water jacket 15 has a frame 151 formed with two through holes, a barrel portion 152 joined to the frame 151, and a third sealing member 153 provided between the frame 151 and the barrel portion 152. The frame 151 and the barrel portion 152 are sealed by the third sealing member 153. In the water jacket joining process, the two radiators 12 are joined to the water jacket 15 respectively in a state in which the two radiators 12 are inserted into each of the two through holes of the frame 151 one by one.

[0050] In addition, the number of radiators joined to one water jacket is not limited to two, and may be three or more. Figure 8 It is shown Figure 7 FIG. 1 is a top view of a modified example of the frame 151 . When one water jacket 15 is connected to six radiators 12 , six through holes 154 are formed in the frame 151 .

[0051] As described above, according to the manufacturing method of the power module 1 involved in the first embodiment of the present invention, in the transfer molding process, the subassembly 11 is bonded to the heat sink 12 via the bonding material 13 by using the resin injected into the inner side of the molding die 2. In the conventional manufacturing method of the power module, the heat sink bonding process of bonding the subassembly 11 to the heat sink 12 is a process different from the transfer molding process. Therefore, in the conventional manufacturing method of the power module, a curing process is required after the transfer molding process and after the heat sink bonding process. As a result, the manufacturing time of the power module 1 is prolonged. On the other hand, in the manufacturing method of the power module 1 involved in the first embodiment, the subassembly 11 and the heat sink 12 are bonded to each other by the transfer molding process. In other words, the transfer molding process and the heat sink bonding process are performed simultaneously. Therefore, the curing process is one time. As a result, the manufacturing time of the power module 1 can be shortened. In addition, there is no need for equipment for the heat sink bonding process. As a result, the manufacturing equipment of the power module 1 can be simplified. In addition, according to the power module 1 involved in the first embodiment of the present invention, the resin portion 14 is integrally formed with the heat sink 12. Thus, when the resin portion 14 is formed, the subassembly 11 is bonded to the heat sink 12 via the bonding material 13. As a result, the manufacturing time of the power module 1 can be shortened.

[0052] In addition, according to the method for manufacturing the power module 1 according to the first embodiment of the present invention, in the transfer molding step, the subassembly 11 is bonded to the heat sink 12 via the bonding material 13 by using the resin injected into the inner side of the mold 2. In the conventional method for manufacturing a power module, the heat sink bonding step is performed after the transfer molding step. Therefore, in the conventional method for manufacturing a power module, due to the pressure and heat applied to the subassembly 11 in the heat sink bonding step, peeling may occur between the first electrode 111 and the semiconductor element 112 or between the second electrode 113 and the semiconductor element 112. Therefore, in the conventional method for manufacturing a power module, in the heat sink bonding step, it is impossible to apply pressure to the bonding material 13 to remove the bubbles contained in the bonding material 13 from the bonding material 13. As a result, in the conventional method for manufacturing a power module, the heat dissipation and insulation of the bonding material 13 are reduced. On the other hand, in the method for manufacturing the power module 1 according to the first embodiment, pressure is applied to the bonding material 13 by using the pressure of the resin injected into the inner side of the mold 2. Therefore, it is possible to suppress the peeling between the first electrode 111 and the semiconductor element 112 or between the second electrode 113 and the semiconductor element 112, and the heat dissipation and insulation of the bonding material 13 can be improved. As a result, the reliability of the power module 1 can be improved. In addition, according to the power module 1 involved in the first embodiment of the present invention, the resin portion 14 and the heat sink 12 are integrally formed. Thus, when the resin portion 14 is formed, the subassembly 11 is bonded to the heat sink 12 via the bonding material 13. Thus, when the resin portion 14 is formed, pressure is applied to the bonding material 13. Therefore, it is possible to suppress the peeling between the first electrode 111 and the semiconductor element 112 or between the second electrode 113 and the semiconductor element 112, and the heat dissipation and insulation of the bonding material 13 can be improved. As a result, the reliability of the power module 1 can be improved.

[0053] In addition, according to the manufacturing method of the power module 1 involved in the first embodiment of the present invention, a part of the heat sink 12 is covered by the resin part 14 in the transfer molding process. In the conventional manufacturing method of the power module, the heat sink 12 is not covered by the resin part 14. In other words, the heat sink 12 is not bonded to the resin part 14. Therefore, in the conventional manufacturing method of the power module, due to the difference in linear expansion coefficient between the subassembly 11 and the heat sink 12, stress is applied to the bonding material 13 when the ambient temperature changes, and there is a possibility of peeling between the bonding material 13 and the subassembly 11 or between the bonding material 13 and the heat sink 12. As a result, in the conventional manufacturing method of the power module, the heat dissipation and insulation of the power module 1 are poor. On the other hand, in the manufacturing method of the power module 1 involved in the first embodiment, a part of the heat sink 12 is covered by the resin part 14 in the transfer molding process. As a result, the heat sink 12 is bonded to the resin part 14. Therefore, the stress applied to the bonding material 13 when the ambient temperature changes is reduced. Thus, it is possible to suppress the occurrence of peeling between the bonding material 13 and the subassembly 11 or the heat sink 12. As a result, the heat dissipation and insulation of the power module 1 can be improved. In addition, according to the power module 1 involved in the first embodiment of the present invention, the resin portion 14 and the heat sink 12 are integrally formed. Therefore, the stress applied to the bonding material 13 when the ambient temperature changes is reduced. Thus, it is possible to suppress the occurrence of peeling between the bonding material 13 and the subassembly 11 or the heat sink 12. As a result, it is possible to improve the heat dissipation and insulation of the power module 1.

[0054] Furthermore, in the manufacturing method of the power module 1 involved in Embodiment 1, a portion of the heat sink 12 is covered by the resin portion 14 in the transfer molding process. In the conventional manufacturing method of the power module 1, the heat sink 12 is not covered by the resin in the transfer molding process. Therefore, in the conventional manufacturing method of the power module, in order to improve the rigidity of the heat sink 12, it is necessary to increase the thickness of the heat sink 12. On the other hand, in the manufacturing method of the power module 1 involved in Embodiment 1, a portion of the heat sink 12 is covered by the resin portion 14 in the transfer molding process. Thus, the rigidity of the heat sink 12 can be improved without increasing the thickness of the heat sink 12. Furthermore, according to the power module 1 involved in Embodiment 1 of the present invention, the resin portion 14 is integrally formed with the heat sink 12. The rigidity of the heat sink 12 can be improved without increasing the thickness of the heat sink 12.

[0055] Implementation method 2.

[0056] Fig. 9 This is a cross-sectional view showing a main part of a power module manufactured by a power module manufacturing method according to Embodiment 2 of the present invention. Fig. 9 In the figure, the water jacket 15 is not shown. The subassembly 11 further includes an insulating member 117 and a copper plate 118. The insulating member 117 is made of, for example, ceramic.

[0057] The first electrode 111 is formed of, for example, a copper plate. The first electrode 111 and the insulating member 117 are joined to each other by brazing. The insulating member 117 and the copper plate 118 are joined to each other by brazing.

[0058] The copper plate 118 is bonded to the first surface 123 of the flat plate portion 121 of the heat sink 12 via the bonding material 13. The bonding material 13 is made of a material with high thermal conductivity. In addition, the bonding material 13 is made of a sintered material. As the sintered material, for example, Ag nanoparticles and Cu nanoparticles can be cited. Ag nanoparticles and Cu nanoparticles can be sintered at low temperatures.

[0059] The bonding material 13 is sintered by the pressure and heat of the resin when the resin is injected into the mold 2. The sintering of the bonding material 13 bonds the copper plate 118 and the flat plate portion 121 of the heat sink 12 to each other. The other structures are the same as those of the first embodiment.

[0060] As described above, according to the power module 1 and the manufacturing method thereof according to the second embodiment of the present invention, the bonding material 13 is made of a sintered material. As a result, the bonding strength between the subassembly 11 and the heat sink 12 can be improved compared to the case where the bonding material 13 is made of an adhesive sheet. As a result, the life of the power module 1 can be improved.

[0061] Implementation method 3.

[0062] Fig.10 This is a cross-sectional view showing a main part of a power module manufactured by a power module manufacturing method according to Embodiment 3 of the present invention. Fig.10 , the water jacket 15 is not shown. The second electrode outer portion 113B of the second electrode 113 extends from the resin portion 14 in a direction perpendicular to the flat plate portion 121 of the heat sink 12. The third electrode 114 extends from the resin portion 14 in a direction perpendicular to the flat plate portion 121 of the heat sink 12. The resin portion 14 is integrally formed with the first surface 123 in the heat sink 12. The resin portion 14 is not integrally formed with the side surface in the heat sink 12.

[0063] Fig.11 It is shown Fig.10 The cross-sectional view shows a state where the subassembly 11, the bonding material 13 and the heat sink 12 are arranged on the inner side of the forming mold 2. In the subassembly arrangement step, a heat sink 12 is arranged in the lower mold 21 of the forming mold 2, and a plurality of subassemblies 11 are placed on the first surface 123 of the flat plate portion 121 of the heat sink 12 via the bonding material 13. Fig.11 , two sub-assemblies 11 are shown, but in this example, six sub-assemblies 11 are placed on the first surface 123 of the flat plate portion 121 of one heat sink 12 via the bonding material 13 .

[0064] Furthermore, in the subassembly arrangement step, a fourth sealing member 27 is arranged between the upper die 25 of the forming die 2 and the peripheral portion of the first surface 123 of the flat plate portion 121 of the heat sink 12. Thus, the peripheral portion of the first surface 123 and the forming die 2 are sealed. Six small chambers corresponding to the six subassemblies 11 are formed in the upper die 25 of the forming die 2. In addition, the number of subassemblies 11 is not limited to six, but may be more than one. The other structures are the same as those in Embodiment 1 or Embodiment 2.

[0065] As described above, according to the method for manufacturing the power module 1 involved in the third embodiment of the present invention, in the transfer molding process, each of the plurality of subassemblies 11 is bonded to the heat sink 12 via the bonding material 13. A plurality of small chambers corresponding to the plurality of subassemblies 11 are formed in the upper mold 25 of the molding mold 2. In the case where the plurality of subassemblies 11 are entirely covered by one resin portion 14, the amount of resin used when forming the resin portion 14 increases. In addition, due to the difference in linear expansion coefficient between the heat sink 12 and the resin portion 14, a large warp is generated in the resin portion 14. On the other hand, according to the method for manufacturing the power module 1 involved in the third embodiment, each of the plurality of subassemblies 11 is covered by each resin portion 14. In other words, the plurality of resin portions 14 corresponding to each of the plurality of subassemblies 11 are integrally formed with the heat sink 12. As a result, the amount of resin used when forming the resin portion 14 can be reduced. In addition, the size of the resin portion 14 can be reduced, and thus the occurrence of warping of the resin portion 14 can be suppressed. Furthermore, according to the power module 1 according to the third embodiment of the present invention, the plurality of subassemblies 11 are respectively bonded to the heat sink 12 via the bonding material 13, and the plurality of resin portions 14 are respectively formed integrally with the heat sink 12. Thus, the amount of resin used when forming the resin portion 14 can be reduced, and the occurrence of warping of the resin portion 14 can be suppressed.

[0066] Description of symbols

[0067] 1 Power Module

[0068] 2 Forming die

[0069] 11 Subcomponents

[0070] 12 Radiator

[0071] 13. Joining materials

[0072] 14 Resin Department

[0073] 15 Water Jacket

[0074] 16 Second sealing member

[0075] 21 Lower mold

[0076] 22. First sealing member

[0077] 23 1st pin

[0078] 24 2nd pin

[0079] 25 Upper mold

[0080] 26 Gate

[0081] 27 Fourth sealing member

[0082] 101 U phase upper arm

[0083] 102 U phase lower arm

[0084] 103 V phase upper arm

[0085] 104 V phase lower arm

[0086] 105 W phase upper arm

[0087] 106 W phase lower arm

[0088] 111 1st electrode

[0089] 112 Semiconductor components

[0090] 113 Second electrode

[0091] 113A Inner part of the second electrode

[0092] 113B The outer part of the second electrode

[0093] 114 3rd electrode

[0094] 115 First bonding material

[0095] 116 Second bonding material

[0096] 117 Insulation components

[0097] 118 Copper Plate

[0098] 121 Flat Plate

[0099] 122 heat sink fins

[0100] 123 Surface 1

[0101] 124 Surface 2

[0102] 151 Framework

[0103] 152 Barrel

[0104] 153 Third sealing member

[0105] 154 Through hole.

Claims

1. A method for manufacturing a power module, characterized in that: include: a subassembly placement step of placing a subassembly having a first electrode, a semiconductor element bonded to the first electrode, and a second electrode bonded to the semiconductor element on a heat sink via a bonding material; as well as a transfer molding step in which, after the subassembly arrangement step, a thermoplastic resin is injected into the region surrounded by the heat sink and the molding die in a state where the first electrode, the semiconductor element, and a portion of the second electrode bonded to the semiconductor element, i.e., an inner portion of the second electrode, are arranged in the region; The heat sink has a flat plate portion having a first surface on which the subassembly is placed via the bonding material. In the subassembly arrangement step, one of the heat sinks is arranged in the lower mold of the molding die, a plurality of the subassemblies are placed on the first surface of the flat plate portion of the heat sink via the bonding material, and a sealing member is arranged between the upper mold of the molding die and the peripheral edge of the first surface of the flat plate portion of the heat sink so that the resin is not integrally formed with the side surface of the heat sink. In the transfer molding step, each of the plurality of sub-assemblies is bonded to the heat sink via the bonding material by the resin, and a plurality of small chambers corresponding to the plurality of sub-assemblies are formed in the upper mold of the molding mold. In the transfer molding step, the second pin provided in the molding die abuts against at least two or more pin abutment portions formed on the bonding material, thereby positioning the bonding material relative to the heat sink.

2. The method for manufacturing a power module according to claim 1, wherein: In the transfer molding step, the first pin presses the first electrode toward the heat sink, thereby positioning the first electrode relative to the heat sink.

3. The method for manufacturing a power module according to claim 1 or 2, characterized in that: The two or more pin contact portions are formed on two or more side surfaces of the bonding material.

4. The method for manufacturing a power module according to claim 1 or 2, characterized in that: The two or more pin contact portions are two or more holes formed in the bonding material.

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