Power module, method for manufacturing a power module, joining member for power module, and wiring member for power module

Abstract

To provide a power module that can suppress connection failures caused by the wiring member tilting relative to the substrate after connection between the plate-shaped wiring member and the electrode. [Solution] A power module comprising a substrate having a first electrode and a second electrode, a semiconductor element connected to the first electrode via a first junction layer, a plate-shaped wiring member connected to the semiconductor element via a second junction layer, and a spacer connected to the wiring member via a third junction layer and also connected to the second electrode via a fourth junction layer, wherein the first electrode and the second electrode are electrically connected via the wiring member, and the thermal expansion coefficient of the spacer is smaller than that of the third junction layer and the fourth junction layer.

Description

Technical Field

[0001] The present disclosure relates to a power module, a method for manufacturing a power module, a joining member for a power module, and a wiring member for a power module.

Background Art

[0002] Power modules are used in various fields such as automobiles, railways, power supply equipment, and industrial equipment. A power module includes various members in addition to a base material and semiconductor elements mounted on the base material. Various configurations have been considered as the configuration of the power module (see, for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a power module, from the viewpoint of efficiently flowing a large current, a plate-shaped wiring member may be used instead of a wire-shaped wiring member for connecting a semiconductor element and an electrode (an electrode where the semiconductor element is not disposed). However, when a plate-shaped wiring member is used, the plate-shaped wiring member may be inclined with respect to the substrate depending on the thickness of the semiconductor element, resulting in insufficient connection between the wiring member and the semiconductor element and / or between the wiring member and the electrode, which may cause connection failure. Although attempts have been made to suppress the inclination of the wiring member by increasing the thickness of the bonding layer on the electrode side, in some cases, the inclination of the wiring member cannot be sufficiently suppressed because the bonding layer thermally contracts after the connection between the wiring member and the electrode.

[0005] One aspect of this disclosure aims to provide a power module that can suppress connection failures caused by the wiring member tilting relative to the substrate after connection between the plate-shaped wiring member and the electrode. Another aspect of this disclosure aims to provide a method for manufacturing a power module, a bonding member for a power module, and a wiring member for a power module. [Means for solving the problem]

[0006] One aspect of this disclosure includes, for example, the following [1] to

[28] . [1] A substrate having a first electrode portion and a second electrode portion, A semiconductor element connected via the first electrode and the first junction layer, A plate-shaped wiring member connected to the semiconductor element via a second junction layer, A spacer connected to the wiring member via a third bonding layer, and connected to the second electrode via a fourth bonding layer, Equipped with, The first electrode and the second electrode are electrically connected via the wiring member. A power module in which the thermal expansion coefficient of the spacer is smaller than that of the third bonding layer and the fourth bonding layer. [2] A first substrate having a first electrode, A second substrate having a second electrode, A semiconductor element connected via the first electrode and the first junction layer, A plate-shaped wiring member connected to the semiconductor element via a second junction layer, A spacer connected to the wiring member via a third bonding layer, and connected to the second electrode via a fourth bonding layer, Equipped with, The first electrode and the second electrode are electrically connected via the wiring member. A power module in which the thermal expansion coefficient of the spacer is smaller than that of the third bonding layer and the fourth bonding layer. [3] The power module according to [1] or [2], wherein the composition of the first bonding layer is substantially the same as the composition of the fourth bonding layer. [4] The power module according to any one of [1] to [3], wherein the composition of the second bonding layer is substantially the same as the composition of the third bonding layer. [5] The power module according to any one of [1] to [4], wherein the thickness of the first bonding layer is substantially the same as the thickness of the fourth bonding layer. [6] The power module according to any one of [1] to [5], wherein the thickness of the second bonding layer is substantially the same as the thickness of the third bonding layer. [7] The power module according to any one of [1] to [6], wherein the thickness of the spacer is substantially the same as the thickness of the semiconductor element. [8] The power module according to any one of [1] to [7], wherein the thermal expansion coefficient of the spacer is substantially the same as the thermal expansion coefficient of the semiconductor element. [9] The power module according to any one of [1] to [8], wherein at least one bonding layer selected from the group consisting of the first bonding layer, the second bonding layer, the third bonding layer and the fourth bonding layer is a sintered body.

[10] The power module according to any one of [1] to [9], wherein at least one bonding layer selected from the group consisting of the first bonding layer, the second bonding layer, the third bonding layer and the fourth bonding layer contains copper particles.

[11] The power module according to any one of [1] to

[10] , wherein the outer edge of the third bonding layer is located inside the outer edge of the spacer when viewed from the thickness direction of the substrate.

[12] A step of preparing a laminate comprising a substrate having a first electrode and a second electrode, a semiconductor element disposed on the first electrode via a first junction layer, and a spacer disposed on the second electrode via a fourth junction layer, A step of preparing a wiring member with a bonding layer, comprising a plate-shaped wiring member and a second bonding layer and a third bonding layer disposed on the wiring member, A step of arranging the wiring member with the bonding layer on the laminate such that the semiconductor element and the second bonding layer are in contact, and the spacer and the third bonding layer are in contact, A step of electrically connecting the semiconductor element and the wiring member via the second junction layer, and electrically connecting the spacer and the wiring member via the third junction layer, Equipped with, A method for manufacturing a power module, wherein the thermal expansion coefficient of the spacer is smaller than the thermal expansion coefficient of the third bonding layer and the thermal expansion coefficient of the fourth bonding layer.

[13] A step of preparing a laminate comprising a substrate having a first electrode and a second electrode, a semiconductor element disposed on the first electrode via a first junction layer, and a spacer disposed on the second electrode via a fourth junction layer, The steps include: arranging a second junction layer on the semiconductor element; The steps include: placing a third bonding layer on the spacer, A step of arranging a plate-shaped wiring member so as to extend from the second bonding layer to the third bonding layer, A step of electrically connecting the semiconductor element and the wiring member via the second junction layer, and electrically connecting the spacer and the wiring member via the third junction layer, Equipped with, A method for manufacturing a power module, wherein the thermal expansion coefficient of the spacer is smaller than the thermal expansion coefficient of the third bonding layer and the thermal expansion coefficient of the fourth bonding layer.

[14] The manufacturing method according to

[12] or

[13] , wherein the composition of the first bonding layer and the composition of the fourth bonding layer are substantially the same.

[15] The manufacturing method according to any one of

[12] to [4], wherein the composition of the second bonding layer and the composition of the third bonding layer are substantially the same.

[16] The manufacturing method according to any one of

[12] to [5], wherein the thickness of the first bonding layer and the thickness of the fourth bonding layer are substantially the same.

[17] The manufacturing method according to any one of

[12] to [6], wherein the thickness of the second bonding layer and the thickness of the third bonding layer are substantially the same.

[18] The manufacturing method according to any one of

[12] to [7], wherein the thickness of the semiconductor element is substantially the same as the thickness of the spacer.

[19] The manufacturing method according to any one of

[12] to

[18] , wherein the first bonding layer and the fourth bonding layer are formed of a paste-like bonding material.

[20] The manufacturing method according to any one of

[12] to

[19] , wherein the first bonding layer and the fourth bonding layer are formed of a sheet-like bonding material.

[21] The manufacturing method according to any one of

[12] to

[20] , wherein the second bonding layer and the third bonding layer are formed of a paste-like bonding material.

[22] The manufacturing method according to any one of

[12] to

[21] , wherein the second bonding layer and the third bonding layer are formed of a sheet-like bonding material.

[23] The manufacturing method according to any one of

[12] to

[22] , wherein the thermal expansion coefficient of the spacer is substantially the same as the thermal expansion coefficient of the semiconductor element.

[24] The manufacturing method according to any one of

[12] to

[23] , wherein at least one bonding layer selected from the group consisting of the first bonding layer, the second bonding layer, the third bonding layer, and the fourth bonding layer is a sintered body.

[25] The manufacturing method according to any one of

[12] to

[24] , wherein at least one bonding layer selected from the group consisting of the first bonding layer, the second bonding layer, the third bonding layer, and the fourth bonding layer contains copper particles.

[26] The manufacturing method according to any one of

[12] to

[25] , wherein when viewed in the thickness direction of the substrate, the outer edge of the third bonding layer is located inside the outer edge of the spacer.

[27] A bonding member for a power module, comprising a substrate having a first electrode and a second electrode, a semiconductor element connected to the first electrode via a first bonding layer, and a wiring member connected to the semiconductor element via a second bonding layer, a third bonding layer connected to the wiring member, a fourth bonding layer connected to the second electrode, A spacer disposed between the third bonding layer and the fourth bonding layer and having a coefficient of thermal expansion smaller than the coefficient of thermal expansion of the third bonding layer and the coefficient of thermal expansion of the fourth bonding layer. A bonding member for a power module comprising the above.

[28] A wiring member for a power module comprising a substrate having a first electrode portion and a second electrode portion, wherein the first electrode portion has a semiconductor element. A plate-like wiring member. A second bonding layer disposed on the wiring member and connected to the first electrode portion. A third bonding layer disposed on the wiring member and connected to the second electrode portion. A wiring member for a power module comprising the above.

[0007] One aspect of the present disclosure includes, for example, the following [1] to

[18] . [1] A substrate having a first electrode and a second electrode. A semiconductor element connected to the first electrode via a first bonding layer. A plate-like wiring member connected to the semiconductor element via a second bonding layer. A spacer connected to the wiring member via a third bonding layer and connected to the second electrode via a fourth bonding layer. Comprising the above. The first electrode and the second electrode are electrically connected via the wiring member. A power module in which the coefficient of thermal expansion of the spacer is smaller than the coefficient of thermal expansion of the third bonding layer and the coefficient of thermal expansion of the fourth bonding layer. [2] A first substrate having a first electrode. A second substrate having a second electrode. A semiconductor element connected to the first electrode via a first bonding layer. A plate-like wiring member connected to the semiconductor element via a second bonding layer. A spacer connected to the wiring member via a third bonding layer and connected to the second electrode via a fourth bonding layer. Comprising the above. The first electrode and the second electrode are electrically connected via the wiring member. A power module in which the thermal expansion coefficient of the spacer is smaller than that of the third bonding layer and the fourth bonding layer. [3] The composition of the first bonding layer, the composition of the second bonding layer, the composition of the third bonding layer, and the composition of the fourth bonding layer are all substantially the same. The power module according to [1] or [2], wherein the thickness of the first bonding layer, the thickness of the second bonding layer, the thickness of the third bonding layer, and the thickness of the fourth bonding layer are all substantially the same. [4] The power module according to any one of [1] to [3], wherein the thermal expansion coefficient of the spacer is substantially the same as the thermal expansion coefficient of the semiconductor element. [5] The power module according to any one of [1] to [4], wherein the first bonding layer, the second bonding layer, the third bonding layer and the fourth bonding layer are sintered bodies. [6] The power module according to any one of [1] to [5], wherein the first bonding layer, the second bonding layer, the third bonding layer and the fourth bonding layer contain copper. [7] The power module according to any one of [1] to [6], wherein the outer edge of the third bonding layer is located inside the outer edge of the spacer when viewed from the thickness direction of the substrate. [8] A step of preparing a laminate comprising a substrate having a first electrode and a second electrode, a semiconductor element disposed on the first electrode via a first junction layer, and a spacer disposed on the second electrode via a fourth junction layer, A step of preparing a wiring member with a bonding layer, which includes a plate-shaped wiring member and a second bonding layer and a third bonding layer disposed on the wiring member, A step of arranging the wiring member with the bonding layer on the laminate such that the semiconductor element and the second bonding layer are in contact, and the spacer and the third bonding layer are in contact, A step of electrically connecting the semiconductor element and the wiring member via the second junction layer, and electrically connecting the spacer and the wiring member via the third junction layer, Equipped with, A method for manufacturing a power module, wherein the thermal expansion coefficient of the spacer is smaller than the thermal expansion coefficient of the third bonding layer and the thermal expansion coefficient of the fourth bonding layer. [9] A step of preparing a laminate comprising a substrate having a first electrode and a second electrode, a semiconductor element disposed on the first electrode via a first junction layer, and a spacer disposed on the second electrode via a fourth junction layer, The steps include: arranging a second junction layer on the semiconductor element; The steps include: placing a third bonding layer on the spacer, A step of arranging a plate-shaped wiring member so as to extend from the second bonding layer to the third bonding layer, A step of electrically connecting the semiconductor element and the wiring member via the second junction layer, and electrically connecting the spacer and the wiring member via the third junction layer, Equipped with, A method for manufacturing a power module, wherein the thermal expansion coefficient of the spacer is smaller than the thermal expansion coefficient of the third bonding layer and the thermal expansion coefficient of the fourth bonding layer.

[10] The composition of the first bonding layer, the composition of the second bonding layer, the composition of the third bonding layer, and the composition of the fourth bonding layer are all substantially the same. The manufacturing method according to [8] or [9], wherein the thickness of the first bonding layer, the thickness of the second bonding layer, the thickness of the third bonding layer, and the thickness of the fourth bonding layer are all substantially the same.

[11] A manufacturing method according to any one of [8] to

[10] , wherein the first bonding layer, the second bonding layer, the third bonding layer and the fourth bonding layer are formed by using a paste-like bonding material.

[12] A manufacturing method according to any one of [8] to

[11] , wherein the first bonding layer, the second bonding layer, the third bonding layer and the fourth bonding layer are formed by using a sheet-like bonding material.

[13] The manufacturing method according to any one of [8] to

[12] , wherein the thermal expansion coefficient of the spacer is substantially the same as the thermal expansion coefficient of the semiconductor element.

[14] The manufacturing method according to any one of [8] to

[13] , wherein the first bonding layer, the second bonding layer, the third bonding layer and the fourth bonding layer are sintered bodies.

[15] A manufacturing method according to any one of [8] to

[14] , wherein the first bonding layer, the second bonding layer, the third bonding layer and the fourth bonding layer contain copper.

[16] The manufacturing method according to any one of [8] to

[15] , wherein the outer edge of the third bonding layer is located inside the outer edge of the spacer when viewed from the thickness direction of the substrate.

[17] A bonding member for a power module comprising a substrate having a first electrode and a second electrode, a semiconductor element connected to the first electrode via a first bonding layer, and a wiring member connected to the semiconductor element via a second bonding layer, A third bonding layer connected to the wiring member, A fourth junction layer connected to the second electrode, A spacer is disposed between the third bonding layer and the fourth bonding layer and has a thermal expansion coefficient smaller than that of the third bonding layer and the fourth bonding layer, A joining member for power modules, comprising the above features.

[18] A wiring member for a power module comprising a substrate having a first electrode portion and a second electrode portion, wherein the first electrode portion has a semiconductor element, A plate-shaped wiring component, A second bonding layer is disposed on the wiring member and connected to the first electrode portion, A third bonding layer is disposed on the wiring member and connected to the second electrode portion, Wiring components for power modules, equipped with the following features. [Effects of the Invention]

[0008] According to one aspect of this disclosure, a power module can be provided that can suppress connection failures caused by the plate-shaped wiring member tilting relative to the substrate after connection between the plate-shaped wiring member and the electrode. According to another aspect of this disclosure, a method for manufacturing a power module, a bonding member for a power module, and a wiring member for a power module can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a cross-sectional view showing an example of a power module according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a cross-sectional view showing an example of a power module according to another embodiment of the present disclosure. [Figure 3] Figure 3 is a transparent schematic diagram showing the arrangement of the third bonding layer and the spacer as viewed from the thickness direction of the substrate in a power module according to one embodiment of the present disclosure. [Figure 4] Figure 4 is an enlarged cross-sectional view showing the arrangement of the third bonding layer and the spacer in a power module according to another embodiment of the present disclosure. [Figure 5] Figures 5(a) to 5(c) are cross-sectional views showing the manufacturing method of the semiconductor device shown in Figure 1. [Figure 6] Figures 6(a) and 6(b) are cross-sectional views illustrating the manufacturing method of the semiconductor device shown in Figure 1, and show the steps performed before or after the steps shown in Figure 5. [Figure 7] Figures 7(a) and 7(b) are cross-sectional views illustrating the manufacturing method of the semiconductor device shown in Figure 1, and show the steps performed after the steps shown in Figures 5 and 6. [Figure 8] Figures 8(a) and 8(b) are cross-sectional views showing the manufacturing method of the semiconductor device shown in Figure 1, and show the steps performed after the steps shown in Figure 5. [Figure 9] Figure 9 is a cross-sectional view showing an example of a joining member for a power module according to one embodiment of the present disclosure. [Figure 10] Figure 10 is a cross-sectional view showing an example of a wiring member for a power module according to one embodiment of the present disclosure. [Figure 11] Figure 11 is a cross-sectional view showing an example of a wiring member for a power module according to another embodiment of the present disclosure. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described below. However, this disclosure is not limited to the embodiments described below and can be implemented in various ways within the scope of its gist.

[0011] <Power Module> As shown in Figure 1, a power module 100 according to one embodiment of the present disclosure comprises a substrate 10 having a first electrode 11 and a second electrode 12, a semiconductor element 20 connected to the first electrode 11 via a first bonding layer 1, a plate-shaped wiring member 30 connected to the semiconductor element 20 via a second bonding layer 2, and a spacer 40 connected to the wiring member 30 via a third bonding layer 3 and connected to the second electrode 12 via a fourth bonding layer 4. The first electrode 11 and the second electrode 12 are electrically connected via the wiring member 30. The thermal expansion coefficient of the spacer 40 is smaller than that of the third bonding layer 3 and the fourth bonding layer 4.

[0012] In conventional power modules, the bonding layer shrinks due to heat after the connection of the wiring member to the electrode, which may prevent sufficient suppression of the tilt of the wiring member. On the other hand, in the power module 100 according to one embodiment, a spacer 40 is provided between the third bonding layer 3 and the fourth bonding layer 4 on the electrode side where the semiconductor element 20 is not placed (second electrode 12). Because the thermal expansion coefficient of the spacer 40 is smaller than that of the third bonding layer 3 and the fourth bonding layer 4, the spacer 40 shrinks less due to heat after the connection of the wiring member 30 to the second electrode 12 than the bonding layers (third bonding layer 3 and fourth bonding layer 4), thus suppressing the tilt of the wiring member 30 more than in conventional designs. This makes it possible to suppress connection failures caused by the wiring member 30 tilting relative to the substrate 10.

[0013] The first electrode portion and the second electrode portion may each be made of different substrates. That is, as shown in Figure 2, a power module 200 according to another embodiment of the present disclosure comprises a first substrate 111 having a first electrode 11, a second substrate 112 having a second electrode 12, a semiconductor element 20 connected to the first electrode 11 via a first bonding layer 1, a plate-shaped wiring member 30 connected to the semiconductor element 20 via a second bonding layer 2, and a spacer 40 connected to the wiring member 30 via a third bonding layer 3 and connected to the second electrode 12 via a fourth bonding layer 4, wherein the first electrode 11 and the second electrode 12 are electrically connected via the wiring member 30, and the thermal expansion coefficient of the spacer 40 is smaller than the thermal expansion coefficient of the third bonding layer 3 and the thermal expansion coefficient of the fourth bonding layer 4.

[0014] The constituent material of the substrate 10 may be ceramic. Examples of constituent materials for the substrate 10 include aluminum oxide, aluminum nitride, and silicon nitride.

[0015] The substrate 10 has a first electrode 11 and a second electrode 12. The substrate may be a DBC (Direct Bonded Copper) substrate, an AMB (Active Metal Brazed) substrate, a lead frame, etc. Examples of constituent materials for the first electrode 11 and the second electrode 12 include copper and aluminum.

[0016] The first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 (hereinafter collectively referred to as "bonding layers") may each be composed of the same material or of different materials. The constituent material of the bonding layers may be a metallic material. The metallic material may be a single metal or a metallic compound such as a metallic alloy. Examples of metallic elements constituting the bonding layers include copper, silver, gold, titanium, nickel, palladium, and aluminum. The bonding layers may be composed of a sintered body containing metal (metallic elements) (for example, a sintered body of metal particles such as copper), or a metallic layer formed by sintering and bonding metal particles. Examples of metal (metallic elements) in such a sintered body include copper and silver. At least one bonding layer selected from the group consisting of the first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 may be a sintered body from the viewpoint of electrical conductivity and heat dissipation. At least one bonding layer selected from the group consisting of the first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 may contain at least one selected from the group consisting of solder, copper, and silver, from the viewpoint of electrical conductivity and heat dissipation, and may be a sintered body containing a metal (metal element), may contain copper, or may be a sintered body containing copper. The first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 may be a sintered body containing a metal (metal element), or may be a sintered body containing copper.

[0017] The thermal expansion coefficients of the first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 may be independently 3 ppm / °C or higher, 16.5 ppm / °C or higher, or 19.7 ppm / °C or higher, and may be 25 ppm / °C or lower, 19.7 ppm / °C or lower, or 16.5 ppm / °C or lower. In this specification, the thermal expansion coefficient refers to the value measured by thermomechanical analysis (TMA) when the temperature of the sample is controlled while raising / lowering the temperature, under temperature conditions of 25 to 400°C and a heating rate of 2 to 5°C / min.

[0018] The composition of the first bonding layer 1 may be substantially the same as the composition of the fourth bonding layer 4. In this specification, "substantially the same composition" means that even if there are differences in trace amounts of impurities, the types and amounts of contained components are substantially the same, and there is no difference in chemical properties and physical properties. By making the composition of the first bonding layer 1 substantially the same as the composition of the fourth bonding layer 4, the thermal expansion coefficients of the first bonding layer 1 and the fourth bonding layer 4 become substantially the same, thereby further suppressing connection failures caused by the plate-shaped wiring member 30 tilting relative to the substrate 10. Furthermore, the composition of the second bonding layer 2 may be substantially the same as the composition of the third bonding layer 3. By making the composition of the second bonding layer 2 substantially the same as the composition of the third bonding layer 3, the thermal expansion coefficients of the second bonding layer 2 and the third bonding layer 3 become substantially the same, thereby further suppressing connection failures caused by the plate-shaped wiring member 30 tilting relative to the substrate 10. Furthermore, the compositions of the first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 may each be substantially the same. Since the compositions of the first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 are all substantially the same, the thermal expansion coefficients of the first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 are all substantially the same, thereby further suppressing connection failures caused by the plate-shaped wiring member 30 tilting relative to the substrate 10.

[0019] The thickness of the first bonding layer 1 may be approximately the same as the thickness of the fourth bonding layer 4. In this specification, "approximately the same thickness" means that the absolute value of the difference in thickness is 20 μm or less. Also, the thickness of the second bonding layer 2 may be approximately the same as the thickness of the third bonding layer 3. Furthermore, the thicknesses of the first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 may each be approximately the same. The thicknesses of the first bonding layer 1, the second bonding layer 2, the third bonding layer 3, and the fourth bonding layer 4 may each be independently 20 μm or more, 100 μm or more, or 200 μm or more, or 300 μm or less, 200 μm or less, or 100 μm or less.

[0020] The semiconductor element 20 is an electronic component used for power conversion, control, and supply. Examples of semiconductor elements 20 include IGBTs (Insulated Gate Bipolar Transistors), MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), and diodes.

[0021] Examples of semiconductor materials that constitute the semiconductor device 20 include Si, SiC, GaN, Ge, GaAs, and InP.

[0022] The thermal expansion coefficient of semiconductor element 20 is 2.6 × 10⁻⁶ -6 ppm / °C or higher, 3.0 × 10 -6 ppm / °C or higher, 3.5 ppm / °C or higher, or 4.0 × 10⁻⁶ -6 ppm / ℃ or higher is acceptable, and 4.5 × 10 -6 ppm / ℃ or less, 3.5×10 -6 ppm / ℃ or less, or 3.2 × 10 -6 It may be ppm / °C or less.

[0023] The thickness of the semiconductor element 20 may be 20 μm or more, 60 μm or more, or 150 μm or more, and may be 500 μm or less, 150 μm or less, or 60 μm or less.

[0024] The constituent material of the plate-shaped wiring member 30 may be a metallic material. The metallic material may be a single metal or a metallic compound such as a metallic alloy. Examples of metallic elements constituting the plate-shaped wiring member 30 include copper, silver, gold, titanium, nickel, palladium, aluminum, and molybdenum.

[0025] The plate-shaped wiring member 30 may be a flat plate-shaped wiring member as shown in Figure 1, a stepped wiring member (for example, a clip wiring member), or a ribbon-shaped wiring member.

[0026] The constituent material of the spacer 40 is one that has electrical conductivity and whose thermal expansion coefficient is smaller than that of the third bonding layer 3 and the fourth bonding layer 4. The thermal expansion coefficient of the spacer 40 may be approximately the same as that of the semiconductor element 20, from the viewpoint of more easily suppressing connection failures caused by the tilting of the plate-shaped wiring member 30 relative to the substrate 10. In this specification, "approximately the same thermal expansion coefficient" means that the absolute value of the difference in thermal expansion coefficients is 5 ppm / °C or less. The constituent material of the spacer 40 may be a metallic material. The metallic material may be a single metal or a metallic compound such as a metallic alloy. Examples of metallic elements constituting the spacer 40 include copper, silver, gold, titanium, nickel, palladium, aluminum, and molybdenum.

[0027] The thermal expansion coefficient of the spacer 40 may be 0 ppm / °C or higher, 3 ppm / °C or higher, 5 ppm / °C or higher, 8 ppm / °C or higher, 10 ppm / °C or higher, 12 ppm / °C or higher, 14 ppm / °C or higher, or 16.5 ppm / °C or higher, and may be 19.7 ppm / °C or lower, 16.5 ppm / °C or lower, 14 ppm / °C or lower, 12 ppm / °C or lower, or 10 ppm / °C or lower.

[0028] The thickness of the spacer 40 may be approximately the same as the thickness of the semiconductor element 20. The thickness of the spacer 40 may be 20 μm or more, 60 μm or more, or 150 μm or more, and may be 500 μm or less, 150 μm or less, or 60 μm or less.

[0029] As shown in Figure 3, the outer edge 3a of the third bonding layer 3, when viewed from the thickness direction of the substrate 10, may be located inside the outer edge 40a of the spacer 40. By having the outer edge 3a of the third bonding layer 3 located inside the outer edge 40a of the spacer 40, it is possible to suppress the falling of a portion of the third bonding layer 3 onto the substrate 10, thereby suppressing the occurrence of a short circuit. In another embodiment, from the viewpoint of suppressing the falling of a portion of the third bonding layer onto the substrate, as shown in Figure 4, the thickness of the outer edge 41a of the spacer 41 may be greater than the thickness of the region inside the outer edge 41a of the spacer 41.

[0030] In other embodiments of the power module, in addition to the first and second electrodes, a third electrode disposed on the substrate may further be provided, and a second semiconductor element disposed on the third electrode may further be provided. In this case, the plate-shaped wiring member may also be connected to the second semiconductor element via a bonding layer.

[0031] In the power module 100, the first electrode 11 and the first junction layer 1 may be directly connected, the first junction layer 1 and the semiconductor element 20 may be directly connected, the semiconductor element 20 and the second junction layer 2 may be directly connected, the second junction layer 2 and the wiring member 30 may be directly connected, the wiring member 30 and the third junction layer 3 may be directly connected, the third junction layer 3 and the spacer 40 may be directly connected, the spacer 40 and the fourth junction layer 4 may be directly connected, and the fourth junction layer 4 and the second electrode 12 may be directly connected. In the power module according to other embodiments, there may be other members, junction layers, etc. between the first electrode and the first junction layer, between the first junction layer and the semiconductor element, between the semiconductor element and the second junction layer, between the second junction layer and the wiring member, between the wiring member and the third junction layer, between the third junction layer and the spacer, between the spacer and the fourth junction layer, and between the fourth junction layer and the second electrode.

[0032] <Manufacturing method for power modules> The manufacturing method for the power module 100 described above will be explained with reference to Figures 5 to 8. The manufacturing method for the power module 100 according to one embodiment comprises the following steps. - A step of preparing a laminate 50 comprising a substrate 10 having a first electrode 11 and a second electrode 12, a semiconductor element 20 disposed on the first electrode 11 via a first junction layer 1, and a spacer 40 disposed on the second electrode 12 via a fourth junction layer 4 (laminated preparation step). - A step of preparing a wiring member with a bonding layer 60, which comprises a plate-shaped wiring member 30 and a second bonding layer 2 and a third bonding layer 3 arranged on the wiring member 30 (a step of preparing a wiring member with a bonding layer). - A step of arranging a wiring member with a bonding layer 60 on the laminate 50 such that the semiconductor element 20 and the second bonding layer 2 are in contact, and the spacer 40 and the third bonding layer 3 are in contact (arrangement step of wiring member with bonding layer). - A step (connection step) in which the semiconductor element 20 and the wiring member 30 are electrically connected via the second junction layer 2, and the spacer 40 and the wiring member 30 are electrically connected via the third junction layer 3. In the manufacturing method of the power module 100, the thermal expansion coefficient of the spacer 40 is smaller than that of the third bonding layer 3 and the fourth bonding layer 4. The above steps may be performed in the order shown above, in a different order, or some steps may be performed substantially simultaneously. For example, the step of arranging the wiring member with bonding layer and the connection step may be performed substantially simultaneously.

[0033] The laminate preparation process may include, for example, the following steps: The step of preparing a substrate 10 having a first electrode 11 and a second electrode 12. Step 1: Place the first junction layer 1 on the first electrode 11. The step of placing the semiconductor element 20 on the first junction layer 1. The step of placing the fourth junction layer 4 on the second electrode 12. • A step of placing a spacer 40 on the fourth bonding layer 4. The steps may be performed in the order described above, in a different order, or some steps may be performed almost simultaneously.

[0034] The laminate preparation process may include, for example, the following steps in the following order: - A step of preparing a substrate 10 (such as a DBC substrate) having a first electrode 11 and a second electrode 12 (Figure 5(a)). The first step is to place the first junction layer 1 on the first electrode 11 and the fourth junction layer 4 on the second electrode 12 (Figure 5(b)). The steps include placing the semiconductor element 20 on the first junction layer 1 and placing the spacer 40 on the fourth junction layer 4 (Figure 5(c)).

[0035] In other embodiments, the first electrode portion and the second electrode portion may be on different substrates. When the first electrode portion and the second electrode portion are on different substrates, the method for manufacturing the power module may include the steps of preparing a first substrate having the first electrode and preparing a second substrate having the second electrode in the laminate preparation step.

[0036] The first bonding layer 1 and the fourth bonding layer 4 may be formed by using a paste-like bonding material, or by using a sheet-like bonding material.

[0037] In the laminate preparation process, the first bonding layer 1 and the fourth bonding layer 4 may physically connect (bond) the members that are in contact with the bonding layer, or they may not physically and electrically connect (bond) the members that are in contact with the bonding layer. If the first bonding layer 1 and the fourth bonding layer 4 do not physically and electrically connect (bond) the members that are in contact with the bonding layer, the physical and electrical connection (bonding) of the members by the first bonding layer 1 and the fourth bonding layer 4 may be performed substantially simultaneously with the physical and electrical connection (bonding) of the second bonding layer 2 and the third bonding layer 3 in the bonding process.

[0038] The physical and electrical connection (bonding) of the components by the first bonding layer 1 and the fourth bonding layer 4 is performed by heating the first bonding layer 1 and the fourth bonding layer 4. The heating of the first bonding layer 1 and the fourth bonding layer 4 may be performed by methods such as high-temperature furnace, laser heating, or induction heating. The heating of the first bonding layer 1 and the fourth bonding layer 4 may be performed while cooling from the side opposite to the surface of the substrate 10 on which the first electrode 11 and the second electrode 12 are located.

[0039] The process of preparing wiring components with bonding layers may include, for example, the following steps: • A step of preparing a plate-shaped wiring member 30. - A step of placing the second bonding layer 2 on the plate-shaped wiring member 30. - A step of placing the third bonding layer 3 on the plate-shaped wiring member 30. The steps may be performed in the order described above, in a different order, or some steps may be performed almost simultaneously.

[0040] The process of preparing wiring components with a bonding layer may include, for example, the following steps in the following order: • Step 1: Prepare a plate-shaped wiring member 30 (Figure 6(a)). The second bonding layer 2 and the third bonding layer 3 are placed on the plate-shaped wiring member 30 (Figure 6(b)).

[0041] The second bonding layer 2 and the third bonding layer 3 may be formed by using a paste-like bonding material, or by using a sheet-like bonding material.

[0042] In the wiring member with bonding layer placement step, the wiring member with bonding layer 60 prepared in the wiring member with bonding layer preparation step is placed on the laminate 50 prepared in the laminate preparation step so that the semiconductor element 20 and the second bonding layer 2 are in contact, and the spacer 40 and the third bonding layer 3 are in contact (Figure 7(a)).

[0043] The connection process may include, for example, the following steps: The step of heating the second junction layer 2 to physically and electrically connect the semiconductor element 20 and the wiring member 30 via the second junction layer 2. The third bonding layer 3 is heated to physically and electrically connect the spacer 40 and the wiring member 30 via the third bonding layer 3. Each step may be performed almost simultaneously. That is, the connection step may include heating the second junction layer 2 to physically and electrically connect the semiconductor element 20 and the wiring member 30 via the second junction layer 2, and heating the third junction layer 3 to physically and electrically connect the spacer 40 and the wiring member 30 via the third junction layer 3 (Figure 7(b)).

[0044] In the bonding process, physical and electrical connections (bonding) are made between the second bonding layer 2 and the semiconductor element 20, and between the third bonding layer 3 and the spacer. In the bonding process, the physical and electrical connections between the members by the first bonding layer 1 and the fourth bonding layer 4 may be made approximately simultaneously with the physical and electrical connections between the second bonding layer 2 and the third bonding layer 3.

[0045] The heating of the second bonding layer 2 and the third bonding layer 3 may be carried out by methods such as high-temperature furnace heating, laser heating, or induction heating.

[0046] In the connection process, the second bonding layer 2 and the third bonding layer 3 may be heated while cooling from the side opposite to the side of the substrate 10 on which the first electrode 11 and the second electrode 12 are located.

[0047] In other embodiments, the power module 100 may include the following steps after the laminate preparation step, instead of the preparation step for wiring members with bonding layers and the arrangement step for wiring members with bonding layers. • A step of placing a second junction layer 2 on the semiconductor element 20 (second junction layer placement step). • The process of placing the third bonding layer 3 on the spacer 40 (third bonding layer placement process). - A step of arranging a plate-shaped wiring member 30 so that it extends from the second bonding layer 2 to the third bonding layer 3 (wiring member arrangement step).

[0048] In other words, the manufacturing method of the power module 100 according to another embodiment comprises the following steps. - A step of preparing a laminate 50 comprising a substrate 10 having a first electrode 11 and a second electrode 12, a semiconductor element 20 disposed on the first electrode 11 via a first junction layer 1, and a spacer 40 disposed on the second electrode 12 via a fourth junction layer 4 (laminated preparation step). • A step of placing a second junction layer 2 on the semiconductor element 20 (second junction layer placement step). • The process of placing the third bonding layer 3 on the spacer 40 (third bonding layer placement process). - A step of arranging a plate-shaped wiring member 30 so that it extends from the second bonding layer 2 to the third bonding layer 3 (wiring member arrangement step). - A step (connection step) in which the semiconductor element 20 and the wiring member 30 are electrically connected via the second junction layer 2, and the spacer 40 and the wiring member 30 are electrically connected via the third junction layer 3. The above steps may be performed in the order shown above, in a different order, or some steps may be performed almost simultaneously. For example, as shown in Figures 8(a) and (b), the second bonding layer placement step and the third bonding layer placement step may be performed almost simultaneously, followed by the wiring member placement step.

[0049] <Bonding components for power modules> Another aspect of this disclosure relates to a bonding member for a power module that can be used in a method for manufacturing a power module. As shown in Figure 9, a bonding member for a power module 70 according to one embodiment comprises a substrate having a first electrode and a second electrode, a semiconductor element connected to the first electrode via a first bonding layer, and a wiring member connected to the semiconductor element via a second bonding layer, the bonding member further comprising a third bonding layer 3 connected to the wiring member, a fourth bonding layer 4 connected to the second electrode, and a spacer 40 disposed between the third bonding layer 3 and the fourth bonding layer 4 and having a thermal expansion coefficient smaller than that of the third bonding layer 3 and the fourth bonding layer 4.

[0050] <Wiring components for power modules> Another aspect of this disclosure relates to a wiring member for a power module that can be used in a method for manufacturing a power module. As shown in Figure 10, a wiring member for a power module 80 according to one embodiment comprises a substrate having a first electrode portion and a second electrode portion, wherein the first electrode portion is a semiconductor element, and comprises a plate-shaped wiring member 30, a second junction layer 2 disposed on the wiring member 30 and connected to the first electrode portion, and a third junction layer 3 disposed on the wiring member 30 and connected to the second electrode portion.

[0051] The first electrode portion may include a first electrode placed on a substrate and a semiconductor element placed on the first electrode via a first junction layer. In this case, the second junction layer 2 of the power module wiring member 80 is connected to the semiconductor element of the first electrode portion.

[0052] The second electrode portion has a second electrode disposed on a substrate and may also have a spacer disposed on the second electrode via a fourth bonding layer. When the second electrode portion has a spacer, the third bonding layer 3 of the power module wiring member 80 is connected to the spacer of the second electrode portion. On the other hand, when the second electrode portion does not have a spacer, as shown in Figure 11, the power module wiring member 90 according to another embodiment may include a third bonding layer 3 disposed on the wiring member 30, a spacer 40 disposed on the wiring member 30 via the third bonding layer 3, and a fourth bonding layer 4 disposed on the spacer 40. [Explanation of Symbols]

[0053] 1...First bonding layer, 2...Second bonding layer, 3...Third bonding layer, 3a...Outer edge of the third bonding layer, 4...Fourth bonding layer, 10...Substrate, 11...First electrode, 12...Second electrode, 20...Semiconductor element, 30...Plate-shaped wiring member, 40,41...Spacer, 40a,41a...Outer edge of spacer, 50...Laminate, 60...Wiring member with bonding layer, 70...Bonding member for power module, 80,90...Wiring member for power module, 100,200...Power module.

Claims

1. A substrate having a first electrode and a second electrode, A semiconductor element connected to the first electrode via a first junction layer, A plate-shaped wiring member connected to the semiconductor element via a second junction layer, A spacer connected to the wiring member via a third bonding layer and connected to the second electrode via a fourth bonding layer, Equipped with, The first electrode and the second electrode are electrically connected via the wiring member. A power module in which the thermal expansion coefficient of the spacer is smaller than that of the third bonding layer and the fourth bonding layer.

2. A first substrate having a first electrode, A second substrate having a second electrode, A semiconductor element connected to the first electrode via a first junction layer, A plate-shaped wiring member connected to the semiconductor element via a second junction layer, A spacer connected to the wiring member via a third bonding layer and connected to the second electrode via a fourth bonding layer, Equipped with, The first electrode and the second electrode are electrically connected via the wiring member. A power module in which the thermal expansion coefficient of the spacer is smaller than that of the third bonding layer and the fourth bonding layer.

3. The composition of the first bonding layer, the composition of the second bonding layer, the composition of the third bonding layer, and the composition of the fourth bonding layer are all substantially the same. The power module according to claim 1 or 2, wherein the thickness of the first bonding layer, the thickness of the second bonding layer, the thickness of the third bonding layer, and the thickness of the fourth bonding layer are all substantially the same.

4. The power module according to claim 1 or 2, wherein the thermal expansion coefficient of the spacer is substantially the same as the thermal expansion coefficient of the semiconductor element.

5. The power module according to claim 1 or 2, wherein the first bonding layer, the second bonding layer, the third bonding layer, and the fourth bonding layer are sintered bodies.

6. The power module according to claim 1 or 2, wherein the first bonding layer, the second bonding layer, the third bonding layer, and the fourth bonding layer contain copper.

7. The power module according to claim 1 or 2, wherein, when viewed from the thickness direction of the substrate, the outer edge of the third bonding layer is located inside the outer edge of the spacer.

8. A step of preparing a laminate comprising a substrate having a first electrode and a second electrode, a semiconductor element disposed on the first electrode via a first junction layer, and a spacer disposed on the second electrode via a fourth junction layer, A step of preparing a wiring member with a bonding layer, which includes a plate-shaped wiring member and a second bonding layer and a third bonding layer disposed on the wiring member, A step of arranging the wiring member with the bonding layer on the laminate such that the semiconductor element and the second bonding layer are in contact, and the spacer and the third bonding layer are in contact, A step of electrically connecting the semiconductor element and the wiring member via the second junction layer, and electrically connecting the spacer and the wiring member via the third junction layer, Equipped with, A method for manufacturing a power module, wherein the thermal expansion coefficient of the spacer is smaller than the thermal expansion coefficient of the third bonding layer and the thermal expansion coefficient of the fourth bonding layer.

9. A step of preparing a laminate comprising a substrate having a first electrode and a second electrode, a semiconductor element disposed on the first electrode via a first junction layer, and a spacer disposed on the second electrode via a fourth junction layer, The steps include: arranging a second junction layer on the semiconductor element; The steps include: placing a third bonding layer on the spacer, A step of arranging a plate-shaped wiring member so as to extend from the second bonding layer to the third bonding layer, A step of electrically connecting the semiconductor element and the wiring member via the second junction layer, and electrically connecting the spacer and the wiring member via the third junction layer, Equipped with, A method for manufacturing a power module, wherein the thermal expansion coefficient of the spacer is smaller than the thermal expansion coefficient of the third bonding layer and the thermal expansion coefficient of the fourth bonding layer.

10. The composition of the first bonding layer, the composition of the second bonding layer, the composition of the third bonding layer, and the composition of the fourth bonding layer are all substantially the same. The manufacturing method according to claim 8 or 9, wherein the thickness of the first bonding layer, the thickness of the second bonding layer, the thickness of the third bonding layer, and the thickness of the fourth bonding layer are all substantially the same.

11. The manufacturing method according to claim 8 or 9, wherein the first bonding layer, the second bonding layer, the third bonding layer, and the fourth bonding layer are formed by using a paste-like bonding material.

12. The manufacturing method according to claim 8 or 9, wherein the first bonding layer, the second bonding layer, the third bonding layer, and the fourth bonding layer are formed by using a sheet-like bonding material.

13. The manufacturing method according to claim 8 or 9, wherein the thermal expansion coefficient of the spacer is substantially the same as that of the semiconductor element.

14. The manufacturing method according to claim 8 or 9, wherein the first bonding layer, the second bonding layer, the third bonding layer, and the fourth bonding layer are sintered bodies.

15. The manufacturing method according to claim 8 or 9, wherein the first bonding layer, the second bonding layer, the third bonding layer, and the fourth bonding layer contain copper.

16. The manufacturing method according to claim 8 or 9, wherein, when viewed from the thickness direction of the substrate, the outer edge of the third bonding layer is located inside the outer edge of the spacer.

17. A bonding member for a power module comprising a substrate having a first electrode and a second electrode, a semiconductor element connected to the first electrode via a first bonding layer, and a wiring member connected to the semiconductor element via a second bonding layer, A third bonding layer connected to the wiring member, A fourth junction layer connected to the second electrode, A spacer is disposed between the third bonding layer and the fourth bonding layer and has a thermal expansion coefficient smaller than that of the third bonding layer and the fourth bonding layer, A joining member for power modules, comprising the above features.

18. A wiring member for a power module comprising a substrate having a first electrode portion and a second electrode portion, wherein the first electrode portion has a semiconductor element, A plate-shaped wiring component, A second bonding layer is disposed on the wiring member and connected to the first electrode portion, A third bonding layer is disposed on the wiring member and connected to the second electrode portion, Wiring components for power modules, equipped with the following features.

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