JP6287789B2 - Power module and manufacturing method thereof - Google Patents

Description

  The present invention relates to a power module and a manufacturing method thereof.

  In conventional power modules, wires are used for wiring between power semiconductor elements, between power semiconductor elements and circuit patterns, and the like. Here, in order to increase the current capacity of the power module, it is necessary to increase the number of wires. However, since the area where wires can be bonded is limited, the current capacity of the power module can be increased in a structure using wires for wiring such as between power semiconductor elements or between a power semiconductor element and a circuit pattern. difficult.

  For this reason, a structure has been devised in which wiring is performed between power semiconductor elements, between a power semiconductor element and a circuit pattern, using plate-like wiring instead of wires. The plate-like wiring is bonded to the member to be bonded by ultrasonic bonding. However, due to the presence of oxide film, dirt, or microscopic unevenness on the surface of the plate-like wiring and the member to be joined, there is no gap between the plate-like wiring after ultrasonic bonding and the member to be joined. Bonding portions remain and bonding failure occurs.

  Therefore, the surface to be joined to the member to be joined corresponding to the plate-like wiring is curved in a convex shape, and the convex surface is directed to the member to be joined. The ultrasonic application means is pressed on the surface, ultrasonic waves are applied, and the leads and the members to be bonded are ultrasonically bonded, thereby suppressing the generation of unbonded portions (for example, Patent Document 1).

JP 2012-039018 A

  In such a power module, the plate-like wiring is curved in a convex shape in one direction and is ultrasonically bonded to the member to be joined, so that the member to be joined is curved in the direction of the plate-like wiring. If it is curved in the same direction as the plate-like wiring and the plate-like wiring after being ultrasonically bonded due to the presence of oxide film, dirt or microscopic irregularities on the surface of the member to be joined An unjoined portion between the members still remains. Further, when the member to be joined is curved in a direction different from the direction in which the plate-like wiring is curved, at the start of ultrasonic joining, a deviation occurs in the region where the plate-like wiring and the member to be joined are in contact, and joining is performed. No ultrasonic vibration is applied to the entire interface, leaving an unjoined part.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a power module in which unjoined portions between a plate-like wiring and a power semiconductor element are reduced.

A power module according to the present invention includes a heat sink, an insulating plate provided on the heat sink, a circuit pattern formed on the insulating plate, a power disposed on the circuit pattern, and an electrode formed on the surface side. A first porous member comprising: a semiconductor element; a metallic first porous member disposed on the electrode; and a plate-shaped first wiring disposed on the first porous member. The shape of the surface in contact with the first wiring is circular or elliptical .

  According to the power module of the present invention, when the plate-like wiring and the power semiconductor element are joined, the plate-like wiring and the power semiconductor element are joined via the first porous member. It is possible to obtain a power module in which the unjoined portion between the wiring and the power semiconductor element is reduced. This is because, when the plate-like wiring and the power semiconductor element are joined, even if the power semiconductor element is curved, the first porous member is deformed, so that the first porous member spreads over the entire joining interface. It is.

It is sectional drawing which shows schematically the structure of the power module concerning Embodiment 1 of this invention, (a) and (b) differ in the structure between a power semiconductor element and a heat sink. It is a process flow figure showing a manufacturing method of a power module concerning Embodiment 1 of the present invention. It is the side view and bottom view which show the wiring and porous member for demonstrating step S1 of the process of the manufacturing method of the power module concerning Embodiment 1 of this invention. It is a figure for demonstrating step S2 of the process of the manufacturing method of the power module concerning Embodiment 1 of this invention, (a) is just before the start of step S2, (b) is just after the start of step S2, (c ) Is immediately after the end of step S2. It is sectional drawing of the power semiconductor element for describing the modification of step S1 of the process of the manufacturing method of the power module concerning Embodiment 1 of this invention, a circuit pattern, and a porous member. It is the side view and bottom view which show the wiring and porous member for demonstrating step S1 of the process of the manufacturing method of the power module concerning Embodiment 2 of this invention, (a) made one porous member. In this case, (b) shows a case where a plurality of porous members are used. FIG. 9 is a side view and a bottom view of a modified example showing wiring and a porous member for explaining step S1 of the process of the method for manufacturing a power module according to the second embodiment of the present invention, and is different from the porous member of FIG. The porous member of a shape is shown, (a) is a case where there is one porous member, and (b) is a case where there are a plurality of porous members. FIGS. 8A and 8B are a side view and a bottom view of a modified example showing wiring and a porous member for explaining step S1 of the process of the method for manufacturing a power module according to the second embodiment of the present invention, and FIG. The porous member of the shape different from a member is shown, (a) is a case where the number of porous members is one, (b) is a case where a plurality of porous members are used. It is sectional drawing which shows schematically the structure of the power module concerning Embodiment 3 of this invention. It is sectional drawing which shows roughly the structure of the power module concerning Embodiment 4 of this invention.

Embodiment 1 FIG.
The configuration of the power module according to the first embodiment of the present invention will be described. FIG. 1 is a cross-sectional view schematically showing a configuration of a power module according to Embodiment 1 of the present invention, in which (a) and (b) are different in configuration between a power semiconductor element and a heat sink.

  First, the power module 100 according to the first embodiment of the present invention shown in FIG. The power module 100 in FIG. 1A is disposed on the heat sink 13, the insulating plate 8 provided on the heat sink 13, the circuit pattern 7 formed on the insulating plate 8, and the circuit pattern 7. A power semiconductor element 5 having an electrode 4 formed on the surface, a metallic first porous member 2 disposed on the electrode 4, and a plate-like first disposed on the first porous member 2 The wiring 1 is provided. Furthermore, the second porous member 21 is disposed on the circuit pattern 7 and has a plate-like second wiring 3 disposed on the second porous member 21. The insulating plate 8 has a metal pattern 9 formed on the surface opposite to the surface on which the circuit pattern 7 is formed, and the metal pattern 9 and the heat radiating plate 13 are bonded via an insulating substrate bonding material 61. The power semiconductor element 5 is bonded to the circuit pattern 7 via an element bonding material 6.

  The power module 100 includes a case 14 that houses the insulating plate 8, the circuit pattern 7, the metal pattern 9, the power semiconductor element 5, the first porous member 2, and the second porous member 21. A surface of the heat radiating plate 13 facing the insulating plate 8, the insulating plate 8, the circuit pattern 7, the metal pattern 9, the power semiconductor element 5, the first porous member 2, and the second porous member. A first sealing resin 16 for sealing the material member 21 is provided. The first sealing resin 16 is filled in the case 14.

  Next, the power module 101 concerning Embodiment 1 of this invention of FIG.1 (b) is demonstrated. The power module 101 in FIG. 1B is disposed on the heat sink 13, the insulating plate 81 provided on the heat sink 13, the circuit pattern 7 formed on the insulating plate 81, and the circuit pattern 7. A power semiconductor element 5 having an electrode 4 formed on the surface, a metallic first porous member 2 disposed on the electrode 4, and a plate-like first disposed on the first porous member 2 The wiring 1 is provided. Further, it is provided with a metallic second porous member 21 disposed on the circuit pattern 7 and a plate-like second wiring 3 disposed on the second porous member. The surface of the insulating plate 81 opposite to the surface on which the circuit pattern 7 is formed is joined to the heat radiating plate 13. The power semiconductor element 5 is bonded to the circuit pattern 7 via an element bonding material 6.

  The power module 101 includes a case 14 that houses the insulating plate 81, the circuit pattern 7, the power semiconductor element 5, the first porous member 2, and the second porous member 21. 81, the circuit pattern 7, the power semiconductor element 5, the first porous member 2, and the first sealing resin 16 that seals the second porous member 21 are provided. The first sealing resin 16 is filled in the case 14.

  Here, the power semiconductor element 5 is an insulated gate bipolar transistor (IGBT), a free wheel diode (FWD), or the like. Of course, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) may be used.

  The shape of the electrode 4 formed on the surface of the power semiconductor element 5 is not particularly limited.

  Although copper is used for the first wiring 1 and the second wiring 3 here, the present invention is not limited to this. The first wiring 1 and the second wiring 3 are preferably made of a material having high electrical conductivity. Here, since the first wiring 1 and the second wiring 3 are used for the input and output of the current and voltage of the power modules 100 and 101, the circuit inside the power modules 100 and 101 passes through the case 14. And an external device to which the power modules 100 and 101 are connected.

  The insulating plate 8 is made of ceramic, which is an inorganic material, such as alumina (Aluminum Oxide), aluminum nitride (Aluminum Nitride), silicon nitride (Silicon Nitride), or the like. The insulating plate 81 is filled with an organic material such as epoxy resin, polyimide resin, cyanate resin, etc. and ceramic filler such as alumina (aluminum oxide), aluminum nitride (aluminum nitride), boron nitride (boron nitride), etc. Is used.

  Although copper is used for the circuit pattern 7 here, a material having high electrical conductivity that can be bonded to the insulating plate 8 or 81 by a direct bonding method or an active metal bonding method may be used. The direct bonding method is a method of bonding by direct reaction between the copper of the circuit pattern 7 and the inorganic material of the insulating plate 8 or 81. The active metal bonding method is a method of bonding to the insulating plate 8 or 81 through a brazing material to which an active metal such as titanium or zirconium is added. The circuit pattern 7 is selectively formed with respect to the circuit design configured by the power module 100 or 101.

  Although copper is used for the metal pattern 9 here, it is not limited to this. The material of the metal pattern 9 needs to be a material that can be bonded to the insulating plate 8 by a direct bonding method or an active metal bonding method, and can be bonded to the heat radiating plate 13 via the insulating substrate bonding material 61, and more preferably heat It is a material with good conductivity. Here, the metal pattern 9 is provided to join the insulating plate 8 and the heat radiating plate 13 via the insulating substrate bonding material 61, and further to transmit heat generated inside when the power module 100 is operated to the heat radiating plate 13. Is provided. In the case where the insulating plate 8, the heat radiating plate 13, and the insulating substrate bonding material 61 are joined without being interposed, the insulating plate 81 is used as the insulating plate. This is because the insulating plate 81 can be bonded to the heat radiating plate 13 by being applied to the heat radiating plate 13 and cured.

  Although copper is used for the heat sink 13 here, a material having good thermal conductivity may be used, and a composite material of silicon carbide and aluminum (Al—SiC) may be used. The heat radiating plate 13 has a function of radiating heat generated inside during operation of the power modules 100 and 101 to the outside and a function as a part of the housing. In FIG. 1, the heat radiating plate 13 is provided below the case 14, but there may be a portion where the case 14 covers a part of the heat radiating plate 13. 14 may surround. The surface of the heat radiating plate 13 opposite to the surface facing the insulating plate 8 or the surface opposite to the surface where the insulating plate 81 of the heat radiating plate 13 is joined, that is, the lower surface of the heat radiating plate 13 in FIG. And what is necessary is just to be able to thermally radiate the heat | fever of the power module 100 or 101. FIG.

  The element bonding material 6 and the insulating substrate bonding material 61 use solder here, but may be a silver nanoparticle paste or a silver paste containing an epoxy resin that is a so-called conductive adhesive.

  For the case 14, an insulating material having high heat resistance is used, and for example, a heat-resistant thermoplastic resin such as polyphenylene sulfide or polybutylene terephthalate is used.

  A silicon resin is used for the first sealing resin 16. For example, a urethane resin, an epoxy resin, a polyimide resin, a polyamide resin, a polyamideimide resin, an acrylic resin, a rubber material, or the like may be used. Further, an epoxy resin may be stacked on a gel-like silicon resin.

  The first porous member 2 and the second porous member 21 use metal, and here, a case where the same copper as that of the first wiring 1 and the second wiring 3 is used as the constituent element will be described. The first porous member 2 and the second porous member 21 are made of copper, aluminum, silver, nickel, or gold because of electrical characteristics and mechanical characteristics in the power module manufacturing method described later. It is preferable to use an alloy mainly composed of any of these. Since the 1st porous member 2 and the 2nd porous member 21 are porous as the name shows, they have a plurality of fine holes. Each of the first porous member 2 and the second porous member 21 has a ratio of about 30% of a plurality of fine holes. If it is about 30%, the electrical resistance between the power semiconductor element 5 and the first wiring 1 or between the circuit pattern 7 and the second wiring 3 is not extremely increased.

  The raw material for forming the first porous member 2 and the second porous member 21 may be a purchased product, or in the method for manufacturing the power modules 100 and 101 according to the first embodiment of the present invention. As will be described later, it may be formed on the first wiring 1 and the second wiring 3 including the generation of the material. As a method of using a purchased product, for example, Celmet (registered trademark) manufactured by Sumitomo Electric Industries, Ltd. sold as a porous metal is purchased as a material of the first porous member 2, and this material is made to a necessary size. The first porous member 2 is processed. Next, the first porous member 2 is brazed to the surface of the first wiring 1 to be joined to the power semiconductor element 5, and the first wiring 1 and the power semiconductor element 5 are connected to the first porous member. 2 is joined.

  At this time, the material of the first porous member 2 to be purchased is selected to be softer than the first wiring 1. The material of the second porous member 21 is also selected to be softer than the second wiring 3. Here, the term “softer than the first wiring 1” means that the Vickers hardness or yield stress (0.2% yield strength) is higher than the Vickers hardness or yield stress (0.2% yield strength) of the first wiring 1. Indicates a small one.

  Next, a method for manufacturing the power modules 100 and 101 according to the first embodiment of the present invention will be described. First, when manufacturing the power module 100, the power in which the circuit pattern 7 is formed on one surface of the insulating plate 8, the metal substrate 9 is bonded on the other surface, and the electrode 4 is formed on the surface. A semiconductor element 5 is prepared. Then, an insulating substrate is placed on the heat radiating plate 13 via the insulating substrate bonding material 61 so that the metal pattern 9 is on the heat radiating plate 13 side, and the power semiconductor is disposed on the circuit pattern 7 of the insulating substrate via the element bonding material 6. Element 5 is placed and placed in a reflow furnace. By putting in the reflow furnace, the insulating substrate bonding material 61 and the element bonding material 6 are melted, and the heat sink 13, the insulating substrate, and the power semiconductor element 5 are bonded.

  When the power module 101 is manufactured, an insulating plate 81 is bonded on one surface of the heat radiating plate 13, and further, a metal substrate having the circuit pattern 7 bonded on the insulating plate 81, and an electrode 4 on the surface. A formed power semiconductor element 5 is prepared. And the power semiconductor element 5 is arrange | positioned through the element bonding material 6 on the circuit pattern 7 of a metal substrate, and it puts into a reflow furnace. Then, when the element bonding material 6 is melted, the metal substrate and the power semiconductor element 5 are bonded.

  Thereby, the preparation for manufacturing the power module 100 or 101 is completed.

  Next, the plate-like wiring is joined using the first porous member 2 and the second porous member 21. FIG. 2 is a process flow diagram illustrating a process of joining plate-like wirings in the manufacturing method of the power modules 100 and 101 according to the first embodiment of the present invention. In step S <b> 1 shown in FIG. 2, the first porous member 2 is formed on one surface of the first wiring 1, and the second porous member 21 is formed on one surface of the second wiring 3. To do. In step S2, the first wiring 1 that is a plate-like wiring and the electrode 4 of the power semiconductor element 5 are joined via the first porous member 2, and the second wiring that is a plate-like wiring. 3 and the circuit pattern 7 are joined via the second porous member 21.

  Details of step S1 and step S2 in FIG. 2 will be described with reference to FIGS. 3 is a wiring and porous member (first porous member 2 and second porous member) for explaining step S1 of the method of manufacturing the power modules 100 and 101 according to the first embodiment of the present invention. It is the side view and bottom view which show the mass member 21). FIG. 4 is a diagram for explaining step S2 of the process of the method for manufacturing the power modules 100 and 101 according to the first embodiment of the present invention, where (a) is just before the start of step S2, and (b) is the step. Immediately after the start of S2, (c) is immediately after the end of step S2.

  In step S1, as shown in FIG. 3, the first porous member 2 is formed on the surface bonded to the power semiconductor element 5 which is one surface of the first wiring 1. The method for forming the second porous member 21 on the second wiring 3 is also the same method as the method for forming the first porous member 2 on the first wiring 1 described below. it can. Therefore, since it becomes the same description, it abbreviate | omits.

  Here, the surface bonded to the power semiconductor element 5 of the first wiring 1 is the lower surface. The shape of the first porous member 2 was convex in the side view and circular in the bottom view. First, the case where the 1st porous member 2 is formed in the 1st wiring 1 including the production | generation of a raw material is demonstrated. Preferably, a cold spray method or a fine particle sintering method is used as a method of forming the first porous member 2 including the generation of the material on the first wiring 1. The cold spray method is a method of forming a film by spraying metal fine particles onto an object at a high speed. The first porous member 2 can be formed by spraying metal fine particles used for the first porous member 2 on the surface of the first wiring 1 to be bonded to the power semiconductor element 5 at a high speed. The fine particle sintering method is a method in which metal fine particles are deposited on an object, and after deposition, the metal fine particles are baked to form a film. The metal fine particles used for the first porous member 2 are stacked on the surface of the first wiring 1 to be bonded to the power semiconductor element 5, and then the metal fine particles are baked on the first wiring 1, The porous member 2 can be formed. In addition to the cold spray method or the fine particle sintering method, a method of generating the first porous member 2 by injection molding and brazing the surface of the first wiring 1 to be bonded to the power semiconductor element 5 may be used. .

  When using a purchased product for the first porous member 2, as described above, for example, Celmet (registered trademark) manufactured by Sumitomo Electric Industries, Ltd. sold as a porous metal is used as the first porous member 2. This material is processed into a shape as shown in FIG. 3 and brazed to the surface of the first wiring 1 to be joined to the power semiconductor element 5.

  Here, when the first porous member 2 is formed by using the same metal material as that of the first wiring 1 as the metal material forming the first porous member 2, the first material formed in the first wiring 1 is used. The porous member 2 is softer than the first wiring 1 because the density thereof is lower than that of the first wiring 1. This is because the hardness generally decreases as the density of the porous metal decreases.

  When the first porous member 2 is formed by using the metal material forming the first porous member 2 as a metal material different from that of the first wiring 1, the first porous member 2 is the first wiring 1. To be softer. To make the first porous member 2 softer than the first wiring 1, the Vickers hardness or the yield stress (0.2%) of the first porous member 2 after being formed on the first wiring 1. It shows that the yield strength) is smaller than the Vickers hardness or the yield stress (0.2% yield strength) of the first wiring 1.

  That is, even when the same metal material as the first wiring 1 is used for the first porous member 2 or when a different metal material is used, the first porous member 2 formed on the first wiring 1 is used. The Vickers hardness or yield stress (0.2% yield strength) of the first wiring 1 is necessarily smaller than the Vickers hardness or yield stress (0.2% yield strength) of the first wiring 1.

For example, when oxygen-free copper (C1020-1 / 2H) is used for the first wiring 1, the Vickers hardness of the first porous member 2 after being formed on the first wiring 1 is less than 75 kgf / mm ^2. And the yield stress (0.2% yield strength) is less than 250 N / mm ² .

  The hardness relationship of the second porous member 21 with respect to the second wiring 3 is also similar to the hardness relationship of the first porous member 2 with respect to the first wiring 1. That is, even if the same metal material as the second wiring 3 is used for the second porous member 21 or a different metal material is used, the second porous member after being formed in the second wiring 3 is used. The Vickers hardness or yield stress (0.2% yield strength) of the member 21 is necessarily smaller than the Vickers hardness or yield stress (0.2% yield strength) of the second wiring 3.

  Next, in step S <b> 2, the first wiring 1 and the power semiconductor element 5 are joined via the first porous member 2. In addition, the method of joining the second wiring 3 and the circuit pattern 7 via the second porous member 21 also connects the first wiring 1 and the power semiconductor element 5 described below to the first porous member 2. The method similar to the method of joining via can be used. Since the power semiconductor element 5 only becomes the circuit pattern 7 and the description is the same, it is omitted.

  As shown in FIG. 4A, the first wiring 1 is disposed on the electrode 4 formed on the surface of the power semiconductor element 5. Here, the ultrasonic bonding tool 30 exists on the opposite side of the surface of the first wiring 1 on which the first porous member 2 is formed. The first wiring 1 is formed in advance in a predetermined portion of the case 14, and the first wiring 1 is formed on the surface of the power semiconductor element 5 by fixing the case 14 to the heat sink 13. Placed on top.

  Then, as shown in FIG. 4B, ultrasonic bonding is performed so that the first porous member 2 formed on the first wiring 1 is in contact with the electrode 4 formed on the surface of the power semiconductor element 5. The tool 30 is pressed against the first wiring 1 from the upper side, that is, from the side opposite to the surface of the first wiring 1 on which the first porous member 2 is formed, and a load and ultrasonic vibration are applied.

  Then, the deformation of the first porous member 2 starts from the contact region 10 of the electrode 4 formed on the surface of the first porous member 2 and the power semiconductor element 5, and the area of the contact region 10 increases. . And as shown in FIG.4 (c), the whole joining interface of the 1st porous member 2 and the electrode 4 becomes the contact area | region 11, an ultrasonic vibration is applied to the whole joining interface, joining is completed, and 1st The wiring 1 and the power semiconductor element 5 are joined through the first porous member 2.

  The first porous member 2 remains in a porous state even after the first wiring 1 and the power semiconductor element 5 are joined via the first porous member 2. Similarly, the second porous member 21 is maintained in a porous state even after the second wiring 3 and the circuit pattern 7 are joined via the second porous member 21.

  Here, on the lower side of the power semiconductor element 5 in FIG. 4, there are a circuit pattern 7, an insulating plate 8, and a metal pattern 9, the heat radiating plate 13 is omitted, and Embodiment 1 of the present invention in FIG. It is a figure for manufacturing the power module 100 concerning. When manufacturing the power module 101 according to the first embodiment of the present invention shown in FIG. 1B, the circuit pattern 7, the insulating plate 81, and the heat radiating plate 13 are present on the lower side of the power semiconductor element 5. Needless to say.

  Next, the first sealing resin 16 is filled in a region surrounded by the case 14 and the heat radiating plate 13 and cured. Thus, the power modules 100 and 101 according to the first embodiment of the present invention are manufactured.

  An ultrasonic bonding method was used as a method of bonding the first wiring 1 and the power semiconductor element 5 via the first porous member 2. Although a thermocompression bonding method may be used or an ultrasonic combined thermocompression bonding method may be used, an ultrasonic bonding method in which the power semiconductor element 5 is not heated is preferable. The method of joining the second wiring 3 and the circuit pattern 7 via the second porous member 21 is also the same.

  Here, the power module 100 or 101 immediately before step S1 in the state of manufacturing the power modules 100 and 101 according to the first embodiment of the present invention, that is, the first porous member 2 and the second porous member. 21, the first wiring 1 and the second wiring 3, the first sealing resin 16, and the power modules 100 and 101 including the case 14 are warped. This is because it is manufactured by stacking members using various materials having different linear expansion coefficients and putting them in a reflow furnace.

  Therefore, as shown in FIG. 4, the opposing surfaces of the electrode 4 and the first wiring 1 formed on the surface of the power semiconductor element 5 are not parallel to each other. The opposite surfaces of the circuit pattern 7 and the second wiring 3 are the same.

  The thickness of the first porous member 2 and the in-plane dimensions, here the circular diameter, are determined as appropriate. Warpage occurring in the power semiconductor element 5 to which the first wiring 1 is bonded via the first porous member 2, the area of the surface of the first wiring 1 to which the power semiconductor element 5 is bonded, and the power semiconductor This is because it varies depending on the area of the electrode 4 formed on the surface of the element 5.

  For example, the power including the first porous member 2, the second porous member 21, the first wiring 1, the second wiring 3, the first sealing resin 16, and the case 14. When the warp generated in the module 100 or 101 is about 500 μm, it is considered that the first porous member 2 only needs to have a thickness of 250 μm or more and 750 μm or less.

  The power module 100 including the first porous member 2, the second porous member 21, the first wiring 1, the second wiring 3, the first sealing resin 16, and the case 14. Alternatively, when the warp generated in 101 is about 500 μm, the warp generated in the power semiconductor element 5 is smaller than that, and the first wiring 1 is poorly bonded due to the warp generated in the power semiconductor element 5. In order to reduce generation | occurrence | production, it is thought that the thickness of the 1st porous member 2 should just be 250 micrometers or more.

  When the first porous member 2 is thicker than 750 μm, the electrical resistance value of the first porous member 2 increases, and the first wiring 1 is connected via the first porous member 2. When ultrasonic bonding is performed to the power semiconductor element 5, there is a concern that ultrasonic vibrations are not easily transmitted to the bonding interface between the first porous member 2 and the power semiconductor element 5. Is considered to have a thickness of 750 μm or less.

  The thickness and in-plane dimensions of the second porous member 21 are also appropriately determined in the same manner as the first porous member 2.

  In the manufacturing method of the power modules 100 and 101 according to the first embodiment of the present invention described above, the first porous member 2 is formed on the first wiring 1 and the second porous member is formed on the second wiring 3. 21 was formed. Then, the first wiring 1 is bonded to the electrode 4 formed on the surface of the power semiconductor element 5 through the first porous member 2, and the second wiring 3 is connected through the second porous member 21. Bonded to the circuit pattern 7.

  FIG. 5 is a cross-sectional view of a power semiconductor element, a circuit pattern, and a porous member for explaining a modification of step S1 of the process of the method for manufacturing a power module according to the first embodiment of the present invention. In FIG. 5, the first porous member 2 is formed on the electrode 4 formed on the surface of the power semiconductor element 5, and the second porous member 21 is formed on the circuit pattern 7.

  As a modified example of step S1, the first porous member 2 is not formed on the first wiring 1, but the first porous member 2 is formed on the electrode 4 formed on the surface of the power semiconductor element 5 as shown in FIG. The porous member 2 may be formed. As described above, a cold spray method or a fine particle sintering method is used as a method of forming the first porous member 2. Of course, a method of forming the first porous member 2 by injection molding and brazing on the electrode 4 formed on the surface of the power semiconductor element 5 may be used.

  In step S 2, the first wiring 1 is joined to the electrode 4 formed on the surface of the power semiconductor element 5 through the first porous member 2.

  Similarly, when the second wiring 3 is joined to the circuit pattern 7 via the second porous member 21, the second porous member 21 is formed on the second wiring 3 as a modified example of step S1. Instead, the second porous member 21 may be formed on the circuit pattern 7 as shown in FIG. In step S <b> 2, the second wiring 3 is joined to the circuit pattern 7 via the second porous member 21.

  As a further modification of step S1, the first porous member 2 may be formed on both the first wiring 1 and the electrode 4 formed on the surface of the power semiconductor element 5. In step S 2, the first wiring 1 is joined to the electrode 4 formed on the surface of the power semiconductor element 5 through the first porous member 2. Similarly, the second porous member 21 may be formed on both the second wiring 3 and the circuit pattern 7. In step S <b> 2, the second wiring 3 is joined to the circuit pattern 7 via the second porous member 21.

  Since the power modules 100 and 101 according to the first embodiment of the present invention have the above-described configuration and manufacturing method, the power in which the unjoined portion between the first wiring 1 and the power semiconductor element 5 is reduced is reduced. Modules 100 and 101 can be obtained. Further, it is possible to obtain the power modules 100 and 101 in which the unjoined portion between the second wiring 3 and the circuit pattern 7 is reduced.

  This is because when the first wiring 1 and the power semiconductor element 5 are joined, even if the power semiconductor element 5 is curved, as shown in FIG. This is because even if the opposing surfaces are not parallel, the first porous member 2 is porous and metallic, so it is easily deformed, and the first porous member 2 spreads over the entire bonding interface. The same applies between the second wiring 3 and the circuit pattern 7.

  Furthermore, when the first wiring 1 and the power semiconductor element 5 are joined, the first porous member 2 is deformed, so that an excessive load and shear stress are not applied to the power semiconductor element 5. 5 damage can be reduced.

  Further, since the first porous member 2 is present between the first wiring 1 and the power semiconductor element 5, the first porous member 2 generated during the operation of the power modules 100 and 101 is changed from the first porous member 2 to the power semiconductor element 5. The stress applied to the interface between the first wiring 1 and the first porous member 2 and the interface between the electrode 4 formed on the surface of the power semiconductor element 5 and the first porous member 2 is expressed as the first porous member. The plurality of fine holes of 2 can be relaxed by deforming its shape. Therefore, the power modules 100 and 101 can maintain the bonding between the first wiring 1 and the power semiconductor element 5 even when the power modules 100 and 101 are in operation, and the bonding between the first wiring 1 and the power semiconductor element 5. The power modules 100 and 101 with improved reliability can be obtained.

  When the first wiring 1 and the power semiconductor element 5 are bonded via silver paste using a conventional technique, not only the silver filler between the first wiring 1 and the power semiconductor element 5, There are also conductive resins such as epoxy resins. In addition, when the first wiring 1 and the power semiconductor element 5 are joined via the silver nanoparticle paste, not only the silver nanoparticles but also the organic material is interposed between the first wiring 1 and the power semiconductor element 5. There are also dispersants in which the material is used. The silver nanoparticle paste volatilizes the dispersing agent at the time of bonding, but the silver nanoparticle paste has a silver nanoparticle between the first wiring 1 and the power semiconductor element 5 because the dispersing agent is difficult to volatilize at the center of the silver nanoparticle paste. This is because not only the dispersant remains.

  Therefore, when the first wiring 1 and the power semiconductor element 5 are joined via the silver paste, the stress caused by the difference in the linear expansion coefficient between the silver filler and the conductive resin is generated from the silver paste to the first wiring. 1 and the interface between the silver paste and the power semiconductor element 5. Moreover, when the 1st wiring 1 and the power semiconductor element 5 are joined via a silver nanoparticle paste, a silver nanoparticle and the 1st wiring 1 are the center part of the silver nanoparticle paste from which a dispersing agent does not volatilize easily. Or sintering of the power semiconductor element 5 or silver nanoparticles becomes difficult to proceed. As a result, the unsintered part or unjoined part of the silver nanoparticles remains. Thereby, the thermal resistance of a silver nanoparticle junction part increases.

  On the other hand, in Embodiment 1 of the present invention, from the first porous member 2 to the interface between the first wiring 1 and the first porous member 2 and the first porous member 2 and the power semiconductor element 5. Even if the stress applied to the interface is generated, the magnitude of the stress is small, and the value is small as compared with the case of joining with the silver paste. This is because, in the power modules 100 and 101 according to the first embodiment of the present invention, the metallic first porous member 2 that does not contain an organic material is used. This is because no stress is generated due to the difference in coefficient of linear expansion between the metal material and the organic material.

  Moreover, in Embodiment 1 of this invention, the value of the thermal resistance of the junction part using the 1st porous member 2 is small compared with the case where it joins with a silver nanoparticle paste. This is because the power modules 100 and 101 according to the first embodiment of the present invention use the metallic first porous member 2 that does not contain an organic material, and further includes the first porous member 2. This is because bonding by the ultrasonic bonding method shown in FIG. 4 can suppress the remaining of unsintered or unbonded portions of the silver nanoparticles.

  Furthermore, when joining using a silver paste and a silver nanoparticle paste, heat must be applied at the time of joining, and extra heat is applied to the power semiconductor element 5. On the other hand, the first porous member 2 according to the first embodiment of the present invention can join the first wiring 1 and the power semiconductor element 5 by the ultrasonic joining method without using heat. There is an effect that it is not necessary to apply extra heat to the semiconductor element 5.

  The bonding between the second wiring 3 and the circuit pattern 7 also has the same effect as the bonding between the first wiring 1 and the power semiconductor element 5 because the second porous member 21 exists. Therefore, in the power modules 100 and 101, not only the bonding reliability between the first wiring 1 and the power semiconductor element 5, but also the bonding reliability between the second wiring 3 and the circuit pattern 7 is improved.

  Here, the ultrasonic welding tool 30 shown in FIG. 4 has protrusions with a constant pitch. The power module 100 in FIG. 1A and the power module 101 in FIG. 1B have a surface opposite to the surface on which the second porous member 2 of the first wiring 1 is formed, and a second surface. The surface of the wiring 3 opposite to the surface on which the second porous member 2 is formed has irregularities with a constant pitch, which are contact traces of the ultrasonic bonding tool 30. However, the shape of the ultrasonic bonding tool 30 is not particularly limited, and may be one capable of bonding the first wiring 1 and the power semiconductor element 5 and the second wiring 3 and the circuit pattern 7. Therefore, there are also first wirings 1 and 3 that do not have irregularities with a constant pitch as shown in FIGS.

Embodiment 2. FIG.
In the second embodiment of the present invention, portions that are different from the first embodiment of the present invention will be described, and descriptions of the same or corresponding portions will be omitted. In Embodiment 2 of the present invention, the shape of the first porous member 2 formed on the first wiring 1 is different.

  6A and 6B are a side view and a bottom view showing a wiring and a porous member for explaining step S1 in the process of the method for manufacturing a power module according to the second embodiment of the present invention, and FIG. 6A is a porous member. (B) shows a case where a plurality of porous members are used. As shown in FIG. 6, the first porous member 2 is formed on the surface of the first wiring 1 that is bonded to the power semiconductor element 5.

  Here, the surface bonded to the power semiconductor element 5 of the first wiring 1 is the lower surface. In FIG. 6, the first porous member 2 has a convex shape in the side view and an elliptical shape in the bottom view. As described above, in FIG. 6A, the first porous member 2 is formed by one, and in FIG. 6B, a plurality of the first porous members 2 are formed.

  FIG. 6A shows that the first wiring 1 and the power semiconductor element 5 are connected to each other when the shape of the electrode 4 formed on the surface of the power semiconductor element 5 is rectangular and the lengths of opposite sides are different. When joining through the porous member 2, the first porous member 2 is deformed according to the dimensions of the electrode 4 formed on the surface of the power semiconductor element 5, and the first wiring 1, the power semiconductor element 5, The shape of the 1st porous member 2 which can join is shown. Thereby, even when the shape of the electrode 4 formed on the surface of the power semiconductor element 5 is rectangular and the lengths of the opposite sides are different, the same effect as in the first embodiment of the present invention can be obtained. .

  FIG. 6B shows the electrode 4 formed on the surface of the power semiconductor element 5 when the electrode 4 formed on the surface of the power semiconductor element 5 is divided and formed. The shape of the 1st porous member 2 which can be arrange | positioned according to the shape and position is shown. That is, when the electrode 4 formed on the surface of the power semiconductor element 5 is divided and formed, as shown in FIG. 6B, the first porous member 2 is adjusted to its shape and position. A plurality may be formed. Therefore, although three are shown as a plurality of examples in FIG. 6B, the present invention is not limited to this. It goes without saying that the same effects as those of the first embodiment of the present invention can be obtained at this time as well.

  FIG. 7 is a side view and a bottom view showing wiring and a porous member for explaining step S1 of the process of the method for manufacturing a power module according to the second embodiment of the present invention. The porous member of a different shape is shown, (a) is a case where there is one porous member, and (b) is a case where there are a plurality of porous members. As shown in FIG. 7, the first porous member 2 is formed on the surface of the first wiring 1 that is bonded to the power semiconductor element 5.

  Here, the surface bonded to the power semiconductor element 5 of the first wiring 1 is the lower surface. In FIG. 7, the shape of the first porous member 2 is a convex shape in the side view and a rectangular shape, and a rectangular shape in the bottom view. That is, it has a prismatic shape. As described above, in FIG. 7A, one first porous member 2 is formed, and in FIG. 7B, a plurality of first porous members 2 are formed.

  FIG. 7A shows that the first porous member 2 is formed in a rectangular shape so that the first porous member 2 has a convex shape and a circular shape as shown in FIG. 3 or a convex shape as shown in FIG. In addition, it is possible to simplify the formation of the first porous member 2 as compared with the case where the first porous member 2 is formed in an elliptical shape.

  In addition, the volume of the first porous member 2 is larger than the case where the first porous member 2 is formed in a convex and circular shape as shown in FIG. 3 or a convex and elliptical shape as shown in FIG. The case of forming a convex and rectangular shape as shown in FIG. 7 is larger. Therefore, the amount of metal constituting the first porous member 2 is greater when formed as shown in FIG. 7 than when formed as shown in FIG. 3 or FIG. Therefore, in the case of forming as shown in FIG. 7, the heat capacity of the first porous member 2 is increased, and the heat generated during the operation of the power module is easily diffused through the first porous member 2.

  Therefore, the heat dissipation of the power module is improved. Further, the heat dissipation effect as described above is not limited to the case where the first porous member 2 is convex and rectangular, but is convex and circular, such as a cylindrical shape. Even in cases. Of course, it goes without saying that the same effects as those of the first embodiment of the present invention can be obtained.

  FIG. 7B shows a case where the first porous member 2 is replaced with the power semiconductor element when the electrode 4 formed on the surface of the power semiconductor element 5 is divided and formed, as in FIG. The shape of the 1st porous member 2 which can be arrange | positioned according to the shape and position of the electrode 4 formed in the surface of 5 is shown. Therefore, although FIG. 7B shows three examples as a plurality of examples, the present invention is not limited to this. In this case as well, it goes without saying that the same effects as those of the first embodiment of the present invention can be obtained, and in addition, it is needless to say that the above heat dissipation effect can be obtained.

  FIG. 8 is a side view and a bottom view showing the wiring and the porous member for explaining step S1 of the process of the method for manufacturing the power module according to the second embodiment of the present invention. The porous member of the shape different from a porous member is shown, (a) is a case where the number of porous members is one, (b) is a case where a plurality of porous members are used. As shown in FIG. 8, the first porous member 2 is formed on the surface of the first wiring 1 that is bonded to the power semiconductor element 5.

  Here, the surface bonded to the power semiconductor element 5 of the first wiring 1 is the lower surface. In FIG. 8, the shape of the first porous member 2 is a convex shape in a side view, a triangular shape, and a square shape in a bottom view. That is, it has a pyramid shape. In FIG. 8A, as described above, the first porous member 2 is formed by one, and a plurality of the first porous members 2 are formed in FIG. 8B.

  FIG. 8A shows that when the first wiring 1 and the power semiconductor element 5 are joined by forming the first porous member 2 into a pyramid shape, in step S2 of FIG. Since the load concentrates on the tip of the pyramid of the member 2, in addition to the same effects as those of the first embodiment of the present invention, the first porous member 2 can be efficiently deformed. Here, the first porous member 2 shown in FIG. 8A has a square shape in the bottom view, but the first porous member 2 may have a rectangular shape or a circular shape. Has the same effect of efficiently deforming.

  FIG. 8B shows a first porous structure in the case where the electrode 4 formed on the surface of the power semiconductor element 5 is divided and formed, as in FIGS. 6B and 7B. The shape of the 1st porous member 2 which can arrange | position the member 2 according to the shape and position of the electrode 4 formed in the surface of the power semiconductor element 5 is shown. Therefore, although FIG. 8B shows nine examples as a plurality of examples, the present invention is not limited to this. Also in this case, it goes without saying that the same effect as in the first embodiment of the present invention can be obtained. In addition, the effect of efficiently deforming the first porous member 2 as described above can be obtained. Needless to say.

  In the above description using FIG. 6 to FIG. 8, the case where the first porous member 2 is formed on the first wiring 1 is described. However, the first porous member 2 is formed on the power semiconductor element 5. The same applies to the formation on the electrode 4 formed on the surface. The same applies when the second porous member 21 is formed on the second wiring 3, and it goes without saying that the same applies when the second porous member 21 is formed on the circuit pattern 7.

Embodiment 3 FIG.
In the third embodiment of the present invention, parts different from the first embodiment of the present invention and the second embodiment of the present invention will be described, and description of the same or corresponding parts will be omitted. In the third embodiment of the present invention, unlike the first embodiment and the second embodiment of the present invention, the first wiring 1 connects two power semiconductor elements 5.

  FIG. 9 is a cross-sectional view schematically showing the configuration of the power module 102 according to the third embodiment of the present invention. As shown in FIG. 9, the power module 102 according to the third embodiment of the present invention includes a heat sink 13, an insulating plate 8 provided on the heat sink 13, and a circuit pattern 7 formed on the insulating plate 8. And two power semiconductor elements 5 disposed on the circuit pattern 7 and having the electrode 4 formed on the surface thereof, and disposed on each of the electrodes 4 of the two power semiconductor elements 5 to form a metallic first porous A material member 2 and a plate-like first wiring 1 disposed on the two first porous members 2 are provided. That is, the first wiring 1 according to the third embodiment of the present invention is arranged on the electrodes 4 of the two power semiconductor elements 5 and on the electrodes 4 of the two power semiconductor elements 5. The porous member 2 is joined.

  Furthermore, the power module 102 is disposed on the circuit pattern 7 and includes a metallic second porous member 21 and a plate-like second wiring 3 disposed on the second porous member. Yes. The insulating plate 8 has a metal pattern 9 formed on the surface opposite to the surface on which the circuit pattern 7 is formed, and the metal pattern 9 and the heat radiating plate 13 are bonded via an insulating substrate bonding material 61. The two power semiconductor elements 5 are bonded to the circuit pattern 7 via the element bonding material 6.

  The power module 102 includes the insulating plate 8, the circuit pattern 7, the metal pattern 9, the two power semiconductor elements 5, the two first porous members 2, and the second porous member 21. A housing 14 is provided, the surface of the heat sink 13 facing the insulating plate 8, the insulating plate 8, the circuit pattern 7, the metal pattern 9, the two power semiconductor elements 5, and the two first porous bodies A first sealing resin 16 that seals the member 2 and the second porous member 21 is provided.

  As described above, in the power module 102 according to the third embodiment of the present invention, the power module 100 according to the first embodiment of the present invention includes the two power semiconductor elements 5, and the first porous member is provided for each of them. The first wiring 1 connects the two power semiconductor elements 5 and an external device to which the power module 102 is connected.

  When the power module is applied to a circuit such as a motor control, the power module requires an operation for switching current and voltage. Therefore, a circuit for inputting and outputting current and voltage inside the power module is composed of an insulated gate bipolar transistor (IGBT) chip and the like, and a power semiconductor element such as a free wheel diode (FWD) connected in reverse parallel thereto. Become.

  Since the power module 102 according to the third embodiment of the present invention has such a circuit that inputs and outputs current and voltage therein, the first wiring 1 includes two power semiconductor elements 5 and a power module. 102 connects to an external device to which 102 is connected.

  The specifics of each of the two power semiconductor elements 5 depend on the circuit design in the power module 102 according to the third embodiment of the present invention.

  The power module 102 according to the third embodiment of the present invention can achieve the same effects as the power module 101 according to the first embodiment of the present invention.

  Further, the power module 102 according to the third exemplary embodiment of the present invention is configured such that the configuration between the circuit pattern 7 and the heat radiating plate 13 is only the insulating plate 81 as in the power module 101 according to the first exemplary embodiment of the present invention. Also good.

Embodiment 4 FIG.
In the fourth embodiment of the present invention, parts different from the first to third embodiments of the present invention will be described, and description of the same or corresponding parts will be omitted. In the fourth embodiment of the present invention, the configuration of the power module is changed from a so-called case type power module as shown in the first to third embodiments of the present invention to a mold type power module. I made it.

  FIG. 10 is a cross-sectional view schematically showing the configuration of the power module 103 according to the fourth embodiment of the present invention. The power module 103 according to the fourth embodiment of the present invention includes a heat sink 13, an insulating plate 81 provided on the heat sink 13, a circuit pattern 7 formed on the insulating plate 81, and the circuit pattern 7. A power semiconductor element 5 disposed on the surface of which the electrode 4 is formed, a metallic first porous member 2 disposed on the electrode 4, and a plate-shaped member disposed on the first porous member 2. The first wiring 1 is provided. Further, it is provided with a metallic second porous member 21 disposed on the circuit pattern 7 and a plate-like second wiring 3 disposed on the second porous member. The surface of the insulating plate 81 opposite to the surface on which the circuit pattern 7 is formed is joined to the heat radiating plate 13. The power semiconductor element 5 is bonded to the circuit pattern 7 via an element bonding material 6.

  The power module 103 includes a second seal that mold-seals the insulating plate 81, the circuit pattern 7, the power semiconductor element 5, the first porous member 2, and the second porous member 21. A resin 17 is provided.

  The second sealing resin 17 is a mold resin in which an epoxy resin is used. The second sealing resin 17 is a resin that is cured by applying heat and does not return to its original state after being softened. In the power module 103 according to the fourth embodiment of the present invention, the power module 103 including the second sealing resin 17 other than the second sealing resin 17 is placed in a mold, and the second sealing resin 17 that is a mold resin is poured therein, It is manufactured by a transfer mold process that cures by applying heat.

  Since the power module 103 according to the fourth embodiment of the present invention can be manufactured by a transfer molding process, the manufacturing cost can be reduced. Further, like the power module according to the first to third embodiments of the present invention, the first wiring 1, the first porous member 2, the power semiconductor element 5, etc. have a case type structure. The case of the mold type structure sealed with the second sealing resin 17 is stronger than the case where the members constituting the power module are sealed with the first sealing resin 16 using silicon resin or the like. Therefore, it is possible to obtain a power module with improved junction reliability between the first wiring 1 and the power semiconductor element 5 and between the second wiring 3 and the circuit pattern 7.

  Here, the power module 103 according to the fourth embodiment of the present invention is a mold type power module in which the first wiring 1 and the second wiring 3 are lead frames, but the circuit pattern 7 is the lead frame. The location of the lead frame in the molded power module depends on the circuit design that the power module configures.

  In addition, the power module 103 according to the fourth embodiment of the present invention is similar to the power module 100 according to the first embodiment of the present invention in that the configuration between the circuit pattern 7 and the heat radiating plate 13 is the insulating plate 8 and the metal. Pattern 9 may be used.

  Of course, a power module in which the first wiring 1 shown in the third embodiment of the present invention connects two power semiconductor elements 5 and an external device to which the power module 102 is connected is a fourth embodiment of the present invention. It is good also as a mold type power module like the power module 103 concerning.

  In the first to fourth embodiments of the present invention, the first wiring 1 connects the power semiconductor element 5 and an external device. However, the present invention is not limited to this. The first wiring 1 may connect the power semiconductor element 5 and a power semiconductor element different from the power semiconductor element 5. In other words, referring to FIG. 9, the first wiring 1 may connect only two power semiconductor elements 5.

  Further, only the first wiring 1 connected to the power semiconductor element 5 is joined via the first porous member 2, and the second wiring 3 connected to the circuit pattern 7 is connected via the second porous member 21. It is good also as a power module to join without attaching. Furthermore, only the second wiring 3 connected to the circuit pattern 7 is joined via the second porous member 21, and the first wiring 1 connected to the power semiconductor element 5 is connected via the first porous member 2. It is good also as a power module to join without attaching. That is, the power module according to the present invention is one in which there is a plate-like wiring joined through a porous member even at one place in the power module.

  Finally, within the scope of the invention, the present invention can be freely combined with each other, or can be appropriately modified or omitted.

  DESCRIPTION OF SYMBOLS 1 1st wiring, 2 1st porous member, 3rd wiring, 4 electrode, 5 power semiconductor element, 6 element joining material, 7 circuit pattern, 8,81 insulating board, 9 metal pattern, 10,11 Contact region, 13 Heat sink, 16 First sealing resin, 17 Second sealing resin, 21 Second porous member, 30 Ultrasonic bonding tool, 61 Insulating substrate bonding material, 100, 101, 102, 103 Power module.

Claims (16)

A heat sink,
An insulating plate provided on the heat sink;
A circuit pattern formed on the insulating plate;
A power semiconductor element disposed on the circuit pattern and having an electrode formed on the surface side ;
A metallic first porous member disposed on the electrode;
A plate-like first wiring disposed on the first porous member ,
The power module in which the shape of the surface of the first porous member in contact with the first wiring is circular or elliptical . A metallic second porous member disposed on the circuit pattern;
A plate-like second wiring disposed on the second porous member , and
The power module according to claim 1, wherein a shape of the second porous member on a surface in contact with the second wiring is a circular shape or an elliptical shape . A heat sink,
An insulating plate provided on the heat sink;
A circuit pattern formed on the insulating plate;
A power semiconductor element arranged on the circuit pattern and formed by dividing a plurality of electrodes on the surface side ;
A plurality of metallic first porous members arranged in accordance with the position and shape of each of the divided electrodes;
A plate-like first wiring disposed on the first porous member;
A metallic second porous member disposed on the circuit pattern;
A plate-like second wiring disposed on the second porous member;
Power module with The shape of the surface of the first porous member in contact with the first wiring is circular or elliptical.
The power module according to claim 3. The shape of the surface of the second porous member in contact with the second wiring is circular or elliptical.
The power module according to claim 3 or 4. A case for housing the insulating plate, the circuit pattern, the power semiconductor element, the first porous member, and the second porous member ;
A sealing resin filled in the case ;
Power module according to any one of claims 1 to 5 in which Ru further comprising a. Forming a circuit pattern on the insulating plate;
Bonding a power semiconductor element on the circuit pattern via an element bonding member;
Forming a first porous member having a convex tip on a plate-like first wiring ;
A step of bonding the power semiconductor element electrode and the first wiring through the first said that the formed on the wiring first porous member,
A method for manufacturing a power module comprising: Forming a second porous member having a convex tip on the plate-like second wiring ;
A step of bonding the second wiring and the circuit pattern through the second said that the formed on the wiring second porous member,
The method for manufacturing a power module according to claim 7, further comprising : Either one or both of the shape of the first porous member on the surface in contact with the first wiring and the shape of the second porous member on the surface in contact with the second wiring are circular or elliptical. The method for manufacturing a power module according to claim 7 or 8, wherein the method is any one of a shape and a rectangle. Forming a circuit pattern on the insulating plate;
Bonding the back side of the power semiconductor element formed by dividing a plurality of electrodes on the front surface side onto the circuit pattern via an element bonding member;
Forming a plurality of first porous members disposed on the plate-like first wiring in accordance with the positions and shapes of the divided electrodes; and
Bonding the electrode of the power semiconductor element and the plate-like first wiring via the first porous member formed on the first wiring;
Forming a second porous member on the plate-like second wiring;
Bonding the circuit pattern and the second wiring via the second porous member formed on the second wiring;
A method for manufacturing a power module comprising: One or both of the first porous member and the second porous member have a convex shape.
The manufacturing method of the power module of Claim 10. Forming a circuit pattern on the insulating plate;
Bonding the back side of the power semiconductor element having an electrode formed on the surface side, on the circuit pattern via an element bonding member;
On the electrode of the power semiconductor element, a step of forming a first porous member whose tip exhibits a convex shape,
Joining the plate-like first wiring and the electrode of the power semiconductor element via the first porous member formed on the electrode of the power semiconductor element ;
A method for manufacturing a power module comprising: On the circuit pattern, forming a second porous member whose tip exhibits a convex shape,
Joining the plate-like second wiring and the circuit pattern via the second porous member formed on the circuit pattern;
The method for manufacturing a power module according to claim 12, further comprising: Either one or both of the shape of the surface of the first porous member in contact with the electrode of the power semiconductor element and the shape of the surface of the second porous member in contact with the circuit pattern are circular or elliptical. The method for manufacturing a power module according to claim 12 or 13, wherein the power module is any one of a rectangular shape and a rectangular shape. Forming a circuit pattern on the insulating plate;
Bonding the back side of the power semiconductor element formed by dividing a plurality of electrodes on the front surface side onto the circuit pattern via an element bonding member;
Forming a plurality of first porous members arranged on the electrodes of the power semiconductor element in accordance with the positions and shapes of the divided electrodes;
Bonding the plate-like first wiring and the electrode of the power semiconductor element via the first porous member formed on the electrode of the power semiconductor element;
Forming a second porous member on the circuit pattern;
Joining the plate-like second wiring and the circuit pattern via the second porous member formed on the circuit pattern;
A method for manufacturing a power module comprising: The method of manufacturing a power module according to claim 15, wherein tips of one or both of the first porous member and the second porous member have a convex shape.

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