Semiconductor device

Abstract

A semiconductor device includes: first and second semiconductor elements each having a first electrode formed on a front surface side and a control electrode, and a second electrode formed on a back surface side, and performing switching between the first electrode and the second electrode in response to a signal input to the control electrode; a first conductive member electrically connected to the second electrode of the first semiconductor element; a second conductive member electrically connected to the second electrode of the second semiconductor element; a first terminal including a first terminal portion and partially overlapping the first conductive member when viewed from a first direction, and being in conductive junction with the first conductive member at the overlapping portion; and a second terminal including a second terminal portion and being electrically connected to the first electrode of the second semiconductor element, wherein the conductive junction includes a fusion portion in which a portion of each of the first terminal and the first conductive member is fused, and the fusion portion is fused to a middle depth of the first conductive member.

Description

[0001] This application is a divisional application of the original Chinese patent application filed on August 23, 2019, with application number 201980054898.1 and entitled "Joint Structure, Semiconductor Device and Joining Method". Technical Field

[0002] This disclosure relates to a bonding structure formed by joining a first metal member and a second metal member, a semiconductor device having the bonding structure, and a method for joining the first metal member and the second metal member. Background Technology

[0003] In recent years, with the increasing demand for high current and high efficiency in semiconductor devices, there is a growing requirement for low internal resistance. To address this requirement, methods have been developed for directly joining two metal components without the use of bonding wires. For example, Patent Document 1 discloses a technique for joining two metal components (metal terminals and metal plates) using ultrasonic bonding.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-221527 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In ultrasonic bonding, two metal components are joined by pressing one component onto another and applying ultrasonic vibrations. However, ultrasonic bonding can result in wear and tear on the metal components due to friction between them. This surface damage can cause performance degradation in semiconductor devices.

[0009] This disclosure was conceived in view of the aforementioned problems, and its object is to provide a bonding structure that suppresses surface damage caused by the bonding between two metal components. Furthermore, it provides a semiconductor device having the bonding structure and a bonding method between the two metal components.

[0010] Methods for solving problems

[0011] Regarding the joint structure provided by the first aspect of this disclosure, it is a joint structure in which a first metal member and a second metal member overlap when viewed in a first direction and are joined together. In the region where the first metal member and the second metal member overlap, there is a welded portion formed by fusing a portion of each of the first metal member and the second metal member. The welded portion has an annular outer periphery when viewed in the first direction and a plurality of linear marks extending from the interior of the welded portion toward the outer periphery when viewed in the first direction. The plurality of linear marks are bent in a manner that bulges toward one of the annular directions along the outer periphery.

[0012] In a preferred embodiment of the aforementioned joint structure, the aforementioned outer periphery is an annular shape centered on the first reference point, and the aforementioned plurality of linear marks extend from the aforementioned first reference point to the aforementioned outer periphery, and bulge towards the circumferential direction of the aforementioned outer periphery.

[0013] In a preferred embodiment of the aforementioned joint structure, the aforementioned welded portion further has a recessed portion that is circular when viewed in the aforementioned first direction, and the diameter of the aforementioned recessed portion is smaller than the radius of the aforementioned outer periphery.

[0014] In a preferred embodiment of the aforementioned joint structure, the center of the aforementioned recess, when viewed in the aforementioned first direction, is located at the central portion of the line segment connecting the aforementioned first reference point and the aforementioned outer periphery.

[0015] In the preferred embodiment of the aforementioned joint structure, the aforementioned plurality of linear marks are arc-shaped when viewed in the aforementioned first direction, and among a portion of the aforementioned plurality of linear marks, the radius of curvature is smaller the further away from the aforementioned circumferential direction.

[0016] In a preferred embodiment of the aforementioned joint structure, the aforementioned welded portion includes a bottom that overlaps with the aforementioned second metal member when viewed in a second direction orthogonal to the aforementioned first direction.

[0017] In a preferred embodiment of the aforementioned joint structure, the cross-section of the bottom orthogonal to the first direction is annular.

[0018] The semiconductor device provided by the second aspect of this disclosure is a semiconductor device having the bonding structure provided by the first aspect, comprising: an insulating substrate having a main surface and a back surface separated in the first direction, a first conductive member disposed on the main surface, a first switching element electrically connected to the first conductive member, a first terminal including a first terminal portion and electrically connected to the first conductive member, and a second terminal including a second terminal portion and electrically connected to the first switching element.

[0019] In the preferred embodiments of the semiconductor device described above, the fusion portion includes a first joining portion formed from the first terminal as the first metal member to the first conductive member as the second metal member.

[0020] In the preferred embodiments of the semiconductor device described above, the first terminal is thinner than the first conductive member.

[0021] In the preferred embodiments of the semiconductor device described above, there are provided a second conductive member disposed on the main surface separately from the first conductive member, a second switching element in ohmic contact with the second conductive member, and a third terminal including a third terminal portion and electrically connected to the second conductive member, and the first conductive member is electrically connected to the second switching element.

[0022] In the preferred embodiments of the semiconductor device described above, the fusion portion includes a second joining portion formed from the third terminal as the first metal member to the second conductive member as the second metal member.

[0023] In the preferred embodiments of the semiconductor device described above, the third terminal is thinner than the second conductive member.

[0024] In the preferred embodiments of the semiconductor device described above, there is further provided an insulating member sandwiched between the second terminal portion and the third terminal portion in the first direction, and a portion of the insulating member overlaps the second terminal portion and the third terminal portion when viewed in the first direction.

[0025] In the preferred embodiments of the semiconductor device described above, there is further provided a bus bar having a first supply terminal, a second supply terminal, and an insulating body, the second supply terminal is separated from the first supply terminal in the first direction and at least a portion thereof overlaps the first supply terminal when viewed in the first direction, the insulating body is sandwiched between the first supply terminal and the second supply terminal in the first direction, the first supply terminal is in ohmic contact with the second terminal portion, and the second supply terminal is in ohmic contact with the third terminal.

[0026] In the preferred embodiments of the semiconductor device described above, there is further provided a capacitor connected in parallel to the first supply terminal and the second supply terminal.

[0027] In the preferred embodiments of the semiconductor device described above, the fusion portion includes a third joining portion formed from the first supply terminal as the first metal member to the second terminal portion as the second metal member.

[0028] In the preferred embodiment of the semiconductor device described above, the first supply terminal includes a tip portion that is concave in a region overlapping the second terminal portion when viewed in the first direction.

[0029] In the preferred embodiment of the semiconductor device described above, the tip portion includes a base portion and two projecting portions extending from the base portion, and the third joining portions are provided respectively to each of the two projecting portions and the base portion.

[0030] The joining method according to the third aspect of the present disclosure includes a step of preparing a first metal member, a step of preparing a second metal member and arranging the second metal member so as to overlap the first metal member when viewed in a first direction, and a laser welding step of irradiating a laser to the first metal member in a region where the first metal member overlaps the second metal member and welding each portion of the first metal member and the second metal member; in the laser welding step, a first scanning of moving the laser along a first track in a ring shape when viewed in the first direction, and a second scanning of moving a reference position of the first track along a second track are performed.

[0031] In the preferred embodiment of the joining method described above, in the laser welding step, the laser is moved by changing the irradiation position of the laser using a galvanometer scanner.

[0032] In the preferred embodiment of the joining method described above, the first track and the second track are each a circle.

[0033] In the preferred embodiment of the joining method described above, the diameter of the first track is substantially the same as the diameter of the second track.

[0034] In the preferred embodiment of the joining method described above, in the second scanning, the laser is moved along the second track for at least one revolution.

[0035] In the preferred embodiment of the joining method described above, in the second scanning, before the laser is moved along the second track, the laser is irradiated from a center position of the second track, and the laser is moved linearly in a radial direction from the center position of the second track.

[0036] In the preferred embodiment of the joining method described above, the beam diameter of the laser is 20 μm, and the moving speed is 1000 to 1500 mm / s.

[0037] Effects of the Invention

[0038] According to the bonding structure and bonding method of this disclosure, surface damage in the two metal components can be suppressed. Furthermore, according to the semiconductor device of this disclosure, performance degradation can be suppressed by suppressing surface damage in the two metal components. Attached Figure Description

[0039] [ Figure 1 [This is a plan view of the joining structure according to the first embodiment.]

[0040] [ Figure 2 ] is along Figure 1 The cross-sectional view along line II-II is a schematic diagram showing the cross-sectional structure of the joint structure.

[0041] [ Figure 3 This is a schematic diagram showing the laser welding apparatus used in the joining method according to the first embodiment.

[0042] [ Figure 4 [A diagram showing the track of the first scan (first track) and the track of the second scan (second track) of the bonding method according to the first embodiment.]

[0043] [ Figure 5 This is a diagram showing the trajectory of the laser during laser welding.

[0044] [ Figure 6 This is a perspective view showing the semiconductor device according to the first embodiment.

[0045] [ Figure 7 ]for Figure 6 The diagram of the sealing resin is omitted in the 3D representation shown.

[0046] [ Figure 8 [This is a plan view showing the semiconductor device according to the first embodiment.]

[0047] [ Figure 9 ]for Figure 8 The diagram shown depicts the sealing resin represented by imaginary lines.

[0048] [ Figure 10 To be Figure 9 A magnified image obtained by enlarging a portion of it.

[0049] [ Figure 11 This is a front view of the semiconductor device according to the first embodiment.

[0050] [ Figure 12 This is a bottom view of the semiconductor device according to the first embodiment.

[0051] [ Figure 13FIG. 1 is a plan view showing a semiconductor device according to a first embodiment of the present application.

[0052] [ Figure 14 ] is a right side view showing the semiconductor device according to the first embodiment of the present application.

[0053] [ Figure 15 ] is a cross-sectional view taken along the line XV-XV of FIG. 1. Figure 9

[0054] [ Figure 16 ] is a cross-sectional view taken along the line XVI-XVI of FIG. 1. Figure 9

[0055] [ Figure 17 ] is a main part enlarged cross-sectional view obtained by enlarging a part of FIG. 1. Figure 16

[0056] [ Figure 18 ] is a plan view showing a bonded structure according to a modification.

[0057] [ Figure 19 ] is a view showing a second scan track (second and third tracks) of a bonding method according to the modification.

[0058] [ Figure 20 ] is a schematic view showing a cross-sectional structure of a bonded structure according to the modification.

[0059] [ Figure 21 ] is a perspective view showing a semiconductor device according to a second embodiment of the present application.

[0060] [ Figure 22 ] is a plan view showing the semiconductor device according to the second embodiment of the present application.

[0061] [ Figure 23 ] is a bottom view showing the semiconductor device according to the second embodiment of the present application.

[0062] [ Figure 24 ] is a cross-sectional view taken along the line XXIV-XXIV of FIG. 2. Figure 22

[0063] [ Figure 25 ] is a cross-sectional view showing a semiconductor device according to a modification of the second embodiment.

[0064] [ Figure 26 ] is a cross-sectional view showing a semiconductor device according to a modification of the second embodiment.

[0065] [ Figure 27 ] is a perspective view showing a semiconductor device according to a third embodiment of the present application.

[0066] [ Figure 28 ​​​​] is a cross-sectional view for explaining a fusion splice involved in the modification example.

[0067] [ Figure 29 ] is a cross-sectional view for explaining a fusion splice involved in the modification example.

[0068] [ Figure 30 ] is a cross-sectional view for explaining a fusion splice involved in the modification example.

[0069] [ Figure 31 ] is a cross-sectional view for explaining a fusion splice involved in the modification example.

[0070] [ Figure 32 ] is a cross-sectional view for explaining a fusion splice involved in the modification example. DETAILED DESCRIPTION

[0071] Hereinafter, preferred embodiments of the joining structure, the semiconductor device, and the joining method of the present disclosure will be described with reference to the drawings.

[0072] First, the joining structure A1 involved in the first embodiment of the present disclosure will be described with reference to Figure 1 and Figure 2 The joining structure A1 of the first embodiment includes a first metal member 91, a second metal member 92, and a fusion splice 93. Figure 1 is a plan view showing the joining structure A1. Figure 2 is a cross-sectional view along the II-II line of Figure 1 is a schematic view showing the cross-sectional structure of the joining structure A1. For convenience of explanation, the up-down direction of Figure 2 is defined as the thickness direction. That is, Figure 1 the plan view shown in

[0073] The first metal member 91 and the second metal member 92 are, for example, metal plates. The constituent material of the metal plate is, for example, Cu (copper) or a Cu alloy. The first metal member 91 is thinner than the second metal member 92. The thickness of the first metal member 91 is, for example, 0.8 mm, and the thickness of the second metal member 92 is, for example, 3.0 mm. Note that the thickness of each of the first metal member 91 and the second metal member 92 is not limited to this. As shown in Figure 1 , the first metal member 91 and the second metal member 92 partially overlap in the plan view. In addition, the first metal member 91 and the second metal member 92 are arranged in contact with each other in the thickness direction except for the fusion splice 93, as shown in Figure 2 . The first metal member 91 is arranged above (upward of Figure 2 ) the second metal member 92.

[0074] As shown in Figure 2 As shown, the welded portion 93 is formed by welding a portion of the first metal member 91 and a portion of the second metal member 92 together. The first metal member 91 and the second metal member 92 are joined through the welded portion 93. Figure 1 As shown, the welded portion 93 is formed in the area where the first metal member 91 and the second metal member 92 overlap in the plan view. The welded portion 93 is formed by fusing the first metal member 91 and the second metal member 92 through laser welding. Specifically, the welded portion 93 is formed by melting the first metal member 91 and the second metal member 92 through heat generated by laser irradiation, and then solidifying the molten portion. The welded portion 93 is integrally formed with the first metal member 91 and the second metal member 92, respectively. In the portion other than the welded portion 93, the interface between the first metal member 91 and the second metal member 92 is not joined, but rather in an abutting state. The welded portion 93 includes portions where the materials of the first metal member 91 and the second metal member 92 are alloyed, portions made only of the material of the first metal member 91, and portions made only of the material of the second metal member 92. For example, before laser welding, near the junction of the first metal component 91 and the second metal component 92, areas where the materials of the first metal component 91 and the second metal component 92 are alloyed are easily formed. Furthermore, above the welded portion 93 ( Figure 2 The upper part is easily formed into a part consisting only of the material of the first metal component 91.

[0075] 93% of the welded part Figure 1 The figure shown in the plan view has an outer perimeter 931, multiple linear marks 932, and recesses 933. These are weld marks from the laser welding of the first metal component 91 and the second metal component 92.

[0076] The outer perimeter 931 is the boundary between the welded portion 93 and the first metal member 91 in the plan view. The outer perimeter 931 is annular in the plan view, centered on the reference point P1. The diameter of the outer perimeter 931 is, for example, 1.6 mm, but is not limited thereto. Figure 1 In the example shown, the outer perimeter 931 is a perfect circular ring, but it is not limited to this. Deformation and serrations caused by laser welding can also occur.

[0077] Multiple linear marks 932 are rib-like weld marks formed at the weld joint 93 in the plan view. For example... Figure 1 As shown, each linear mark 932 is arc-shaped in the plan view. Specifically, each linear mark 932 extends from the center of the outer periphery 931 to the outer periphery 931 in the plan view, with a reference point P1, and bends in a manner that bulges towards the annular direction along the outer periphery 931. In this embodiment, the outer periphery 931 is annular in the plan view, and therefore the aforementioned annular direction is its circumferential direction. Figure 1 In the illustrated example, each linear mark 932 is curved in a manner that bulges in a counterclockwise direction with respect to the circumferential direction of the outer periphery 931.

[0078] The sunk portion 933 is, for example, circular in plan view. In plan view, the radius of the sunk portion 933 is smaller than the radius of the outer periphery 931. The central position P2 of the sunk portion 933 in plan view is located at a central portion of a line segment connecting the central position (corresponding to the reference point PI) of the outer periphery 931 and the outer periphery 931. Figure 1 In the drawing, a line connecting the center of the line segment is indicated by an auxiliary line LI. As Figure 2 indicated, the outer periphery of the sunk portion 933 protrudes upward.

[0079] As Figure 2 indicated, the fusion portion 93 has an upper portion 934, a body portion 935, and a bottom portion 936 in cross-sectional structure.

[0080] As Figure 2 indicated, the upper portion 934 is a portion of the fusion portion 93 located on the upper side in the thickness direction. The upper portion 934 protrudes upward more than the first metal member 91.

[0081] The body portion 935 is a portion of the fusion portion 93 sandwiched between the upper portion 934 and the bottom portion 936. As Figure 2 indicated, the body portion 935 overlaps the first metal member 91 when viewed in a direction orthogonal to the thickness direction.

[0082] The bottom portion 936 is a portion of the fusion portion 93 located on the lower side in the thickness direction. As Figure 2 indicated, the bottom portion 936 overlaps the second metal member 92 when viewed in a direction orthogonal to the thickness direction. The cross section of the bottom portion 936, for example, in a plane orthogonal to the thickness direction, is circular ring-shaped.

[0083] Next, with reference to Figures 3-5 , a method of forming the joined structure Al related to the first embodiment of the present disclosure, that is, a method of joining the first metal member 91 and the second metal member 92 will be described.

[0084] First, the first metal member 91 and the second metal member 92 are prepared, respectively. For example, a metal plate having a thickness of 0.8 mm is prepared as the first metal member 91, and a metal plate having a thickness of 3.0 mm is prepared as the second metal member 92. Then, at least a portion of the first metal member 91 and at least a portion of the second metal member 92 are arranged in an overlapping manner in the thickness direction (refer to Figure 3 ). At this time, the portions to be joined between the first metal member 91 and the second metal member 92 are arranged in an overlapping manner when viewed in the thickness direction. Then, the first metal member 91 and the second metal member 92 are temporarily fixed by a chuck, not shown in the drawing, or the like.

[0085] Next, the first metal member 91 and the second metal member 92 are laser-welded by irradiating laser light to the region where the first metal member 91 and the second metal member 92 overlap in the plan view. In the present embodiment, a case where the first metal member 91 and the second metal member 92 are laser-welded by irradiating laser light from the surface (the upper surface) of the first metal member 91 as shown in FIG. 1 is described. In this laser-welding process (laser-welding process), for example, YAG laser is used, and laser-welding device LD (refer to FIG. 2) shown below is used. Figure 3 Figure 3 Figure 3

[0086] Figure 3 Figure 3

[0087]

[0088] Figure 4 Figure 5

[0089] ​​​​​​​​The laser fusion apparatus LD performs a first scan in which the laser is moved along a ring-shaped first track Tl in a plan view and a second scan in which a reference position of the first track Tl is moved along a second track T2.

[0090] In the first scan, as shown in FIG. 3A, the laser is irradiated in a manner to draw a circle having a radius R3 centered on a reference position P3. As a result, as shown in FIG. 3B, the track of the laser in the first scan forms a circular first track Tl having a radius R3 centered on the reference position P3. The moving speed of the laser along the first track Tl is set to 1000 to 1500 mm / s as described above. Figure 4 Figure 4 In the first scan, as shown in FIG. 3A, the laser is irradiated in a manner to draw a circle having a radius R3 centered on a reference position P3. As a result, as shown in FIG. 3B, the track of the laser in the first scan forms a circular first track Tl having a radius R3 centered on the reference position P3. The moving speed of the laser along the first track Tl is set to 1000 to 1500 mm / s as described above.

[0091] In the second scan, as shown in FIG. 4A, the reference position P3 in the first scan is moved in a manner to draw a circle having a radius R4 centered on a reference position P4. As a result, the track of the reference position P3 becomes a circular second track T2 having a radius R4 centered on the reference position P4. At this time, the radius R3 of the first track Tl and the radius R4 of the second track T2 are substantially the same. The moving speed of the reference position P3 along the second track T2 is set to about 5 mm / s. Note that the moving speed is not limited to this. In the second scan, the reference position P3 is caused to travel at least one round along the second track T2. In the present embodiment, as shown in FIG. 4B, it is caused to travel one round along the second track T2 and then to travel ¼ round. At this time, during the one round of travel along the second track T2, the energy of the laser is made large (e.g., irradiated at peak power), and during the remaining ¼ round, the energy is made to slowly decrease in a manner such that the time at which ¼ round of travel has been completed is 0 w. Figure 4 Figure 4 In the joining method of the present embodiment, the laser is caused to perform the first scan along the first track Tl and the second scan of the reference position P3 of the first track Tl along the second track T2. As a result, the trajectory of the laser irradiated in the laser fusion process becomes the trajectory shown in FIG. 5B. In the trajectory, the diameter of the outer circumference is about 1.6 mm. In the joining method of the present embodiment, the moving speed of the first scan is about 1000 to 1500 mm / s, and the moving speed of the second scan is about 5 mm / s. As a result, as shown in FIG. 5B, in the trajectory followed by the laser, a portion of each of the plurality of first tracks Tl drawn by the first scan overlaps.

[0092] In the joining method of the present embodiment, the laser is caused to perform the first scan along the first track Tl and the second scan of the reference position P3 of the first track Tl along the second track T2. As a result, the trajectory of the laser irradiated in the laser fusion process becomes the trajectory shown in FIG. 5B. In the trajectory, the diameter of the outer circumference is about 1.6 mm. In the joining method of the present embodiment, the moving speed of the first scan is about 1000 to 1500 mm / s, and the moving speed of the second scan is about 5 mm / s. As a result, as shown in FIG. 5B, in the trajectory followed by the laser, a portion of each of the plurality of first tracks Tl drawn by the first scan overlaps. Figure 5 Figure 5 In the joining method of the present embodiment, the laser is caused to perform the first scan along the first track Tl and the second scan of the reference position P3 of the first track Tl along the second track T2. As a result, the trajectory of the laser irradiated in the laser fusion process becomes the trajectory shown in FIG. 5B. In the trajectory, the diameter of the outer circumference is about 1.6 mm. In the joining method of the present embodiment, the moving speed of the first scan is about 1000 to 1500 mm / s, and the moving speed of the second scan is about 5 mm / s. As a result, as shown in FIG. 5B, in the trajectory followed by the laser, a portion of each of the plurality of first tracks Tl drawn by the first scan overlaps.

[0093] ​​​By irradiating the laser as described above, the portion irradiated with the laser generates heat, and the first metal member 91 is first melted. Also, while the first metal member 91 is melting, heat generation by the laser spreads, and the second metal member 92 is melted. As a result, a molten bath is generated in which a portion of the first metal member 91 and a portion of the second metal member 92 are melted. Thereafter, by moving the position of irradiation of the laser, the heat source generated by the laser is moved, and the generated molten bath cools and solidifies. Then, by the solidification of the molten bath, the first metal member 91 and the second metal member 92 are fused, and the fusion portion 93 is formed. At this time, by moving along the second track T2, melting and solidification are sequentially performed, and thus a plurality of linear marks 932 in the shape of a circular arc are formed in the fusion portion 93 formed. Also, the molten bath generated at the time of stopping the irradiation of the laser solidifies from the periphery thereof, and thus a circular-shaped depression portion 933 is formed in the fusion portion 93 formed. By performing the operation in this manner, the fusion portion 93 across the first metal member 91 and the second metal member 92 is formed by laser fusion, and the first metal member 91 and the second metal member 92 are joined by the fusion portion 93.

[0094] Next, the semiconductor device B1 according to the first embodiment of the present disclosure will be described with reference to Figures 6-17 The semiconductor device B1 according to the first embodiment of the present disclosure will be described. In a portion of the semiconductor device B1 according to the first embodiment, the two metal members are joined by the laser fusion described above. Therefore, the semiconductor device B1 according to the first embodiment has the fusion portion 93 described above, and has the joining structure A1 described above. The semiconductor device B1 has the insulating substrate 10, the plurality of conductive members 11, the plurality of switching elements 20, the two input terminals 31, 32, the output terminal 33, the pair of gate terminals 34A, 34B, the pair of detection terminals 35A, 35B, the plurality of dummy terminals 36, the pair of side terminals 37A, 37B, the pair of insulating layers 41A, 41B, the pair of gate layers 42A, 42B, the pair of detection layers 43A, 43B, the plurality of land portions 44, the plurality of linear connection members 51, the plurality of plate-shaped connection members 52, the sealing resin 60, and the plurality of fusion portions 93. The plurality of switching elements 20 include the plurality of switching elements 20A and the plurality of switching elements 20B.

[0095] Figure 6 A perspective view of the semiconductor device B1 is shown. Figure 7 A view in which the sealing resin 60 in the perspective view shown in Figure 6 A view in which the sealing resin 60 in the perspective view shown in Figure 8 A plan view of the semiconductor device B1 is shown. Figure 9 A view in which the sealing resin 60 in the plan view shown in Figure 8 A view in which the sealing resin 60 in the plan view shown in Figure 10 A view in which a portion of the plan view shown in Figure 9 A view in which a portion of the plan view shown in Figure 11To show a plan view of the semiconductor device B1. Figure 12 To show a bottom view of the semiconductor device B1. Figure 13 To show a side view (left side view) of the semiconductor device B1. Figure 14 To show a side view (right side view) of the semiconductor device B1. Figure 15 To show a cross-sectional view along the XV-XV line of Figure 9 . Figure 16 To show a cross-sectional view along the XVI-XVI line of Figure 9 . Figure 17 To show a main part enlarged cross-sectional view of a part of Figure 16 , showing a cross-sectional structure of the switching element 20.

[0096] For convenience of explanation, Figures 6-17 , three directions orthogonal to each other are defined as an x direction, a y direction, and a z direction. The z direction is a thickness direction of the semiconductor device B1, and corresponds to the thickness direction of the above-mentioned joining structure A1. The x direction is a left-right direction in a plan view (refer to Figure 8 and Figure 9 ) of the semiconductor device B1. The y direction is an up-down direction in the plan view (refer to Figure 8 and Figure 9 ) of the semiconductor device B1. As needed, one of the x directions is set as an x1 direction, and the other of the x directions is set as an x2 direction. Similarly, one of the y directions is set as a y1 direction, and the other of the y directions is set as a y2 direction, one of the z directions is set as a z1 direction, and the other of the z directions is set as a z2 direction.

[0097] As shown in Figure 7 , Figure 9 , Figure 15 and Figure 16 , the insulating substrate 10 is provided with a plurality of conductive members 11. The insulating substrate 10 becomes a support member of the plurality of conductive members 11 and the plurality of switching elements 20. The insulating substrate 10 has electrical insulating properties. The constituent material of the insulating substrate 10 is, for example, a ceramic excellent in thermal conductivity. As such a ceramic, for example, AlN (aluminum nitride) can be cited. In the present embodiment, the insulating substrate 10 is rectangular in plan view. As shown in Figure 15 and Figure 16 , the insulating substrate 10 has a main surface 101 and a back surface 102.

[0098] The main surface 101 and the back surface 102 are separated in the z direction, and face opposite sides to each other. The main surface 101 faces the side in the z direction in which the plurality of conductive members 11 are arranged, that is, the z2 direction. The main surface 101 is covered by the plurality of conductive members 11 and the plurality of switching elements 20, and the sealing resin 60. The back surface 102 faces the z1 direction. As shown in Figure 12 , Figure 15and Figure 16 As shown in FIG. 1, the back surface 102 is exposed from the sealing resin 60. The back surface 102 is connected to, for example, a heat sink or the like not shown in the figure. The configuration of the insulating substrate 10 is not limited to the above-described example, and, for example, each of the plurality of conductive members 11 can be provided separately.

[0099] The plurality of conductive members 11 are each a metal plate. The material of the metal plate is, for example, Cu or a Cu alloy. The plurality of conductive members 11 constitute, together with the 2 input terminals 31, 32 and the output terminal 33, a conduction path to the plurality of switching elements 20. The plurality of conductive members 11 are disposed on the main surface 101 of the insulating substrate 10 and are separated from each other. Each conductive member 11 is joined to the main surface 101 by, for example, a joining material such as Ag (silver) paste. The z-direction dimension of the conductive member 11 is, for example, 3.0 mm, but is not limited thereto. The plurality of conductive members 11 can be covered with an Ag plating layer.

[0100] The plurality of conductive members 11 include 2 conductive members 11A, 11B. As shown in FIG. 1, the conductive member 11A is located closer to the x2 direction than the conductive member 11B. The conductive member 11A mounts the plurality of switching elements 20A. The conductive member 11B mounts the plurality of switching elements 20B. Each of the 2 conductive members 11A, 11B is, for example, rectangular in plan view. In each of the conductive members 11A, 11B, a groove can be formed in a portion of a surface facing the z2 direction. For example, in the conductive member 11A, a groove extending in the y direction can be formed between the plurality of switching elements 20A and an insulating layer 41A (described later) in plan view. Similarly, in the conductive member 11B, a groove extending in the y direction can be formed between the plurality of switching elements 20B and an insulating layer 41B (described later) in plan view. Figure 7 and Figure 9 As shown in FIG. 1, the conductive member 11A is located closer to the x2 direction than the conductive member 11B. The conductive member 11A mounts the plurality of switching elements 20A. The conductive member 11B mounts the plurality of switching elements 20B. Each of the 2 conductive members 11A, 11B is, for example, rectangular in plan view. In each of the conductive members 11A, 11B, a groove can be formed in a portion of a surface facing the z2 direction. For example, in the conductive member 11A, a groove extending in the y direction can be formed between the plurality of switching elements 20A and an insulating layer 41A (described later) in plan view. Similarly, in the conductive member 11B, a groove extending in the y direction can be formed between the plurality of switching elements 20B and an insulating layer 41B (described later) in plan view.

[0101] Each of the conductive members 11A, 11B includes a rough surface region in a portion of a surface thereof (a surface facing the z2 direction). Note that, in FIG. 1, the rough surface region is indicated by hatching. The rough surface region is a rough surface compared to other portions of the surface of the conductive member 11. The rough surface region is formed by irradiating a laser to the surface of the conductive member 11 in the process of manufacturing the semiconductor device B1. Specifically, irradiating a laser to the surface of the conductive member 11 causes the portion irradiated with the laser to melt, and the melted portion solidifies to become a rough surface. Note that, a portion of the portion irradiated with the laser sometimes sublimates. In the rough surface region, the joining strength of the sealing resin 60 can be improved by an anchoring effect. Each of the conductive members 11A, 11B can not include the rough surface region. Figure 9 and Figure 10 As shown in FIG. 1, the conductive member 11A is located closer to the x2 direction than the conductive member 11B. The conductive member 11A mounts the plurality of switching elements 20A. The conductive member 11B mounts the plurality of switching elements 20B. Each of the 2 conductive members 11A, 11B is, for example, rectangular in plan view. In each of the conductive members 11A, 11B, a groove can be formed in a portion of a surface facing the z2 direction. For example, in the conductive member 11A, a groove extending in the y direction can be formed between the plurality of switching elements 20A and an insulating layer 41A (described later) in plan view. Similarly, in the conductive member 11B, a groove extending in the y direction can be formed between the plurality of switching elements 20B and an insulating layer 41B (described later) in plan view.

[0102] The configuration of the multiple conductive components 11 is not limited to the examples described above and can be appropriately modified according to the performance requirements of the semiconductor device B1. For example, the shape, size, and configuration of each conductive component 11 can be changed based on the number and configuration of the multiple switching elements 20.

[0103] The multiple switching elements 20 are MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) made primarily of SiC (silicon carbide) semiconductor materials. It should be noted that the multiple switching elements 20 are not limited to MOSFETs; they can also be field-effect transistors including MISFETs (Metal-Insulator-Semiconductor FETs), bipolar transistors such as IGBTs (Insulated Gate Bipolar Transistors), LSIs, and other IC chips. The example shown is of the case where all switching elements 20 are identical components and are n-channel MOSFETs. Each switching element 20 may be rectangular in a plan view, for example, but is not limited to this.

[0104] like Figure 17 As shown, the multiple switching elements 20 each have a main surface 201 and a back surface 202. Figure 17 The switching element 20A is shown. The main surface 201 and the back surface 202 of the element are separated in the z-direction and face opposite to each other. The main surface 201 of each element faces the same direction as the main surface 101 of the insulating substrate 10. The back surface 202 of each element faces the main surface 101 of the insulating substrate 10.

[0105] like Figure 17 As shown, the multiple switching elements 20 each have a main electrode 21, a back electrode 22, and an insulating film 23.

[0106] The main electrode 21 is located on the main surface 201 of the component. For example... Figure 10 As shown, the main electrode 21 includes a first electrode 211 and a second electrode 212. The first electrode 211 is, for example, a source electrode, through which a source current flows. The second electrode 212 is, for example, a gate electrode, to which a gate voltage for driving each switching element 20 is applied. The first electrode 211 is larger than the second electrode 212. Figure 10 In the example shown, the first electrode 211 is composed of one region, but it is not limited to this and can also be divided into multiple regions.

[0107] The back electrode 22 is disposed on the back side 202 of the component. The back electrode 22 is formed integrally throughout the back side 202 of the component, for example. The back electrode 22 is, for example, a drain electrode, through which drain current flows.

[0108] The insulating film 23 is provided on the element main surface 201. The insulating film 23 has electrical insulating properties. The insulating film 23 surrounds the main surface electrode 21 in a plan view. The insulating film 23 is, for example, a SiO2 (silicon dioxide) layer, a SiN4 (silicon nitride) layer, a polybenzoxazole layer, and is layered in the above order from the element main surface 201. Note that, in the insulating film 23, instead of the polybenzoxazole layer, a polyimide layer can be used.

[0109] As described above, the plurality of switching elements 20 includes the plurality of switching elements 20A and the plurality of switching elements 20B. As Figure 7 and Figure 9 indicated, the semiconductor device B1 includes four switching elements 20A and four switching elements 20B. The number of the plurality of switching elements 20 is not limited by the present configuration, and can be appropriately changed according to the performance required of the semiconductor device B1. For example, in the case where the semiconductor device B1 is a half-bridge type switching circuit, the plurality of switching elements 20A constitutes an upper bridge arm circuit of the semiconductor device B1, and the plurality of switching elements 20B constitutes a lower bridge arm circuit of the semiconductor device B1.

[0110] The plurality of switching elements 20A are mounted on the conductive member 11A as Figure 9 indicated. The plurality of switching elements 20A are arranged side by side in the y direction with separation. As Figure 17 indicated, each switching element 20A is conductively joined to the conductive member 11A via a conductive joining layer 29. The conductive joining layer 29 is configured of, for example, a lead-free solder with Sn (tin) as a main component, but is not limited thereto, and can be an Ag paste. In each switching element 20A, the element back surface 202 faces the upper surface (a surface facing the z2 direction) of the conductive member 11A. The back surface electrode 22 of each switching element 20A is conductive to the conductive member 11A via the conductive joining layer 29.

[0111] The plurality of switching elements 20B are mounted on the conductive member 11B as Figure 9 indicated. The plurality of switching elements 20B are arranged side by side in the y direction with separation. Each switching element 20B is conductively joined to the conductive member 11B via the conductive joining layer 29. In each switching element 20B, the element back surface 202 faces the upper surface (a surface facing the z2 direction) of the conductive member 11B. The back surface electrode 22 of each switching element 20B is conductive to the conductive member 11B via the conductive joining layer 29.

[0112] The two input terminals 31, 32 are each a metal plate. The metal plate is configured of, for example, Cu or a Cu alloy. The z direction dimension of each of the two input terminals 31, 32 is, for example, 0.8 mm, but is not limited thereto. The two input terminals 31, 32 are each mounted on the conductive member 11A as Figure 11The semiconductor device B1 is shown located near the x2 direction. A power supply voltage is applied between the two input terminals 31 and 32, for example. Input terminal 31 is the positive terminal (P terminal), and input terminal 32 is the negative terminal (N terminal). Input terminal 32 is arranged separately from input terminal 31 and conductive member 11A in the z direction.

[0113] like Figure 9 and Figure 15 As shown, the input terminal 31 has a pad portion 311 and a terminal portion 312.

[0114] The pad portion 311 is the part of the input terminal 31 covered by the sealing resin 60. The x1 direction side end of the pad portion 311 is comb-shaped and includes a plurality of comb-tooth portions 311a. The plurality of comb-tooth portions 311a are respectively bonded to the surface of the conductive member 11A via a portion of the welding portion 93 (specifically, the input terminal joint portion 93B described later), and the input terminal 31 is connected to the conductive member 11A via the welding portion 93. The bonding between the comb-tooth portions 311a and the conductive member 11A is performed by laser welding.

[0115] Terminal portion 312 is the part of input terminal 31 that is exposed from sealing resin 60. For example... Figure 9 and Figure 15 As shown, the terminal portion 312 extends from the sealing resin 60 in the x2 direction in the plan view.

[0116] like Figure 9 and Figure 15 As shown, the input terminal 32 has a pad portion 321 and a terminal portion 322.

[0117] The pad portion 321 is the portion of the input terminal 32 covered by the sealing resin 60. The pad portion 321 includes a connecting portion 321a and a plurality of protrusions 321b. The connecting portion 321a is a strip extending in the y-direction. The connecting portion 321a is connected to the terminal portion 322. The plurality of protrusions 321b are strips extending from the connecting portion 321a in the x1-direction. The plurality of protrusions 321b are arranged side by side in the y-direction in a plan view and are separated from each other. The surface of each protrusion 321b facing the z1-direction is in contact with each base portion 44 and is supported by a conductive member 11A across each base portion 44.

[0118] The padding portion 321 includes a rough surface area on a portion of its surface. Figure 9 In the diagram, the rough surface region is indicated by a shading line. The rough surface region is rougher than other portions of the surface of the gasket portion 321. The rough surface region is formed by irradiating the surface of the input terminal 32 with a laser during the manufacturing process of the semiconductor device B1. In this rough surface region, the bonding strength of the sealing resin 60 can be improved using an anchoring effect. The gasket portion 321 may also not include a rough surface region.

[0119] The terminal portion 322 is a portion of the input terminal 32 that is exposed from the sealing resin 60. As shown in Figure 9 and Figure 15 indicated, the terminal portion 322 extends in the x2 direction from the sealing resin 60 in a plan view. The terminal portion 322 is rectangular in a plan view. As shown in Figure 9 and Figure 15 indicated, the terminal portion 322 overlaps the terminal portion 312 of the input terminal 31 in a plan view. The terminal portion 322 is separated from the terminal portion 312 in the z2 direction. Figure 9 and Figure 15 indicated in the example, the shape of the terminal portion 322 is the same as the shape of the terminal portion 312.

[0120] The output terminal 33 is a metal plate. The constituent material of the metal plate is, for example, Cu or a Cu alloy. As shown in Figure 11 indicated, the output terminal 33 is located near the x1 direction in the semiconductor device B1. The alternating current (voltage) that is power-converted is output from the output terminal 33 with the plurality of switching elements 20.

[0121] As shown in Figure 9 and Figure 15 indicated, the output terminal 33 includes a gasket portion 331 and a terminal portion 332.

[0122] The gasket portion 331 is a portion of the output terminal 33 that is covered with the sealing resin 60. A portion of the x2 direction side of the gasket portion 331 is comb-toothed and includes a plurality of comb-tooth portions 331a. The plurality of comb-tooth portions 331a are respectively joined to the surface of the conductive member 11B via a portion of the fusion portion 93 (specifically, the output terminal joining portion 93A described later), and the output terminal 33 is in conduction with the conductive member 11B via the fusion portion 93. The joining of the comb-tooth portions 331a to the conductive member 11B is performed by laser fusion.

[0123] The gasket portion 331 includes a rough surface region on a portion of its surface. Figure 9 In the example, the rough surface region is indicated with hatching. The rough surface region is a rough surface compared to other portions of the surface of the gasket portion 331. The rough surface region is formed by irradiating laser light to the surface of the output terminal 33 during the manufacturing process of the semiconductor device B1. In the rough surface region, the joining strength of the sealing resin 60 can be improved with an anchoring effect. The gasket portion 331 can not include the rough surface region.

[0124] The terminal portion 332 is a portion of the output terminal 33 that is exposed from the sealing resin 60. As shown in Figure 9 and Figure 15 indicated, the terminal portion 332 protrudes from the sealing resin 60 in the x1 direction.

[0125] As shown in Figures 8-10 and Figure 12 As shown in FIG. 1, a pair of gate terminals 34A, 34B are located in the y direction at positions adjacent to the respective conductive members 11A, 11B. A gate voltage for driving the plurality of switching elements 20A is applied to the gate terminal 34A. A gate voltage for driving the plurality of switching elements 20B is applied to the gate terminal 34B.

[0126] As shown in FIG. 1, a pair of gate terminals 34A, 34B are located in the y direction at positions adjacent to the respective conductive members 11A, 11B. A gate voltage for driving the plurality of switching elements 20A is applied to the gate terminal 34A. A gate voltage for driving the plurality of switching elements 20B is applied to the gate terminal 34B. Figure 9 Figure 10 As shown in FIG. 1, a pair of gate terminals 34A, 34B are located in the y direction at positions adjacent to the respective conductive members 11A, 11B. A gate voltage for driving the plurality of switching elements 20A is applied to the gate terminal 34A. A gate voltage for driving the plurality of switching elements 20B is applied to the gate terminal 34B.

[0127] As shown in FIG. 1, a pair of gate terminals 34A, 34B are located in the y direction at positions adjacent to the respective conductive members 11A, 11B. A gate voltage for driving the plurality of switching elements 20A is applied to the gate terminal 34A. A gate voltage for driving the plurality of switching elements 20B is applied to the gate terminal 34B. Figures 8-10 Figure 12 As shown in FIG. 1, a pair of gate terminals 34A, 34B are located in the y direction at positions adjacent to the respective conductive members 11A, 11B. A gate voltage for driving the plurality of switching elements 20A is applied to the gate terminal 34A. A gate voltage for driving the plurality of switching elements 20B is applied to the gate terminal 34B.

[0128] As shown in FIG. 1, a pair of gate terminals 34A, 34B are located in the y direction at positions adjacent to the respective conductive members 11A, 11B. A gate voltage for driving the plurality of switching elements 20A is applied to the gate terminal 34A. A gate voltage for driving the plurality of switching elements 20B is applied to the gate terminal 34B. Figure 9 Figure 10 As shown in FIG. 1, a pair of gate terminals 34A, 34B are located in the y direction at positions adjacent to the respective conductive members 11A, 11B. A gate voltage for driving the plurality of switching elements 20A is applied to the gate terminal 34A. A gate voltage for driving the plurality of switching elements 20B is applied to the gate terminal 34B.

[0129] As shown in FIG. 1, a pair of gate terminals 34A, 34B are located in the y direction at positions adjacent to the respective conductive members 11A, 11B. A gate voltage for driving the plurality of switching elements 20A is applied to the gate terminal 34A. A gate voltage for driving the plurality of switching elements 20B is applied to the gate terminal 34B. Figures 8-10 Figure 12 As shown in FIG. 1, a pair of gate terminals 34A, 34B are located in the y direction at positions adjacent to the respective conductive members 11A, 11B. A gate voltage for driving the plurality of switching elements 20A is applied to the gate terminal 34A. A gate voltage for driving the plurality of switching elements 20B is applied to the gate terminal 34B.

[0130] As​​​​ Figure 9 and Figure 10 As shown, each of the plurality of virtual terminals 36 has a pad portion 361 and a terminal portion 362. In each virtual terminal 36, the pad portion 361 is covered by a sealing resin 60. Thus, each virtual terminal 36 is supported by the sealing resin 60. Ag plating may be applied, for example, to the surface of each pad portion 361. Each terminal portion 362 is connected to each pad portion 361 and is exposed from the sealing resin 60. When viewed in the x-direction, each terminal portion 362 forms an L-shape. Figures 6 to 14 In the example, the shape of each terminal portion 362 is the same as the shape of each terminal portion 342 of the pair of gate terminals 34A, 34B and the shape of each terminal portion 352 of the pair of detection terminals 35A, 35B.

[0131] like Figure 7 , Figure 9 and Figure 16 As shown, a pair of side terminals 37A and 37B are disposed on the end edge portion of the sealing resin 60 in the y1 direction and are also the end edge portions of the sealing resin 60 in the x direction in the plan view. Figure 9 and Figure 16 As shown, a pair of side terminals 37A and 37B each have a pad portion 371 and an end face 372.

[0132] In each of the side terminals 37A and 37B, the gasket portion 371 is covered by sealing resin 60. For example... Figure 9 As shown, a portion of each padding portion 371 is curved in the plan view. Furthermore, as... Figure 16 As shown, the remaining portions of each pad portion 371 are bent in the z-direction. The pad portion 371 of the side terminal 37A is joined to the conductive member 11A via a portion of the weld portion 93 (the side terminal joint portion 93D described in detail below), and the pad portion 371 of the side terminal 37B is joined to the conductive member 11B via a portion of the weld portion 93 (the side terminal joint portion 93C described in detail below). Thus, the side terminal 37A is supported by the conductive member 11A, and the side terminal 37B is supported by the conductive member 11B.

[0133] Each pad portion 371 includes a rough surface area on a portion of its surface. Figure 9 In the diagram, the rough surface region is indicated by a shading line. The rough surface region is rougher than other portions of the surface of each pad portion 371. The rough surface region is formed by irradiating the surfaces of a pair of side terminals 37A and 37B with a laser during the manufacturing process of the semiconductor device B1. In this rough surface region, the bonding strength of the sealing resin 60 can be improved using an anchoring effect. Each side terminal 37A and 37B may also not include a rough surface region.

[0134] Of the side terminals 37A and 37B, the end face 372 protrudes from the sealing resin 60. The end face 372 of side terminal 37A faces in the x2 direction, for example, and is substantially on the same surface as the resin side surface 631. It should be noted that they may not be on the same surface. The end face 372 of side terminal 37B faces in the x1 direction, for example, and is substantially on the same surface as the resin side surface 632. It should be noted that they may not be on the same surface. All side terminals 37A and 37B overlap with the sealing resin 60 in the plan view.

[0135] The configuration of the side terminals 37A and 37B is not limited to the examples described above. For example, in a plan view, they may extend outwards until they protrude from the resin sides 631 and 632, respectively. Furthermore, the semiconductor device B1 may also be without the side terminals 37A and 37B.

[0136] like Figures 8-10 As shown, a pair of gate terminals 34A and 34B, a pair of detection terminals 35A and 35B, and a plurality of dummy terminals 36 are arranged along the x-direction in a plan view. In semiconductor device B1, a pair of gate terminals 34A and 34B, a pair of detection terminals 35A and 35B, a plurality of dummy terminals 36, and a pair of side terminals 37A and 37B are all formed from the same lead frame.

[0137] The insulating member 39 has electrical insulation properties, and its constituent material is, for example, insulating paper. A portion of the insulating member 39 is a flat plate, such as... Figure 15 As shown, the terminal portion 312 of input terminal 31 and the terminal portion 322 of input terminal 32 are sandwiched in the z-direction. In the plan view, the entire input terminal 31 overlaps with the insulating member 39. Furthermore, in the plan view, a portion of the pad portion 321 and the entire terminal portion 322 of input terminal 32 overlap with the insulating member 39. The two input terminals 31 and 32 are insulated from each other by the insulating member 39. A portion of the insulating member 39 (the portion on the x1 direction side) is covered by sealing resin 60.

[0138] like Figure 15 As shown, the insulating member 39 has a sandwich portion 391 and a protruding portion 392. The sandwich portion 391 is sandwiched between the terminal portion 312 of the input terminal 31 and the terminal portion 322 of the input terminal 32 in the z direction. The sandwich portion 391 is entirely sandwiched between the terminal portion 312 and the terminal portion 322. The protruding portion 392 extends further from the sandwich portion 391 in the x2 direction than the terminal portion 312 and the terminal portion 322.

[0139] A pair of insulating layers 41A and 41B are electrically insulating, and their constituent materials are, for example, glass epoxy resin. Figure 9 As shown, a pair of insulating layers 41A and 41B are strips extending in the y direction. Figure 9 , Figure 10 , Figure 15 and Figure 16 As shown in FIG. 1A, the insulating layer 41A is joined to the upper surface (a surface facing the z2 direction) of the conductive member 11A. The insulating layer 41A is positioned closer to the x2 direction than the plurality of switching elements 20A. As shown in FIG. 1A, the insulating layer 41A is positioned closer to the x2 direction than the plurality of switching elements 20A. Figure 9 , Figure 10 , Figure 15 and Figure 16 As shown in FIG. 1B, the insulating layer 41B is joined to the (surface facing the z2 direction) of the conductive member 11B. The insulating layer 41B is positioned closer to the x1 direction than the plurality of switching elements 20B.

[0140] The pair of gate layers 42A, 42B have conductivity, and the constituent material thereof is, for example, Cu. The pair of gate layers 42A, 42B are each a band shape extending in the y direction, as shown in FIG. 1A and FIG. 1B. Figure 9 As shown in FIG. 1A, the gate layer 42A is disposed on the insulating layer 41A. The gate layer 42A is in conduction with the 2nd electrode 212 (gate electrode) of each switching element 20A via a linear connection member 51 (specifically, a gate line 511 described later). As shown in FIG. 1A, the gate layer 42A is positioned closer to the x2 direction than the plurality of switching elements 20A. Figure 9 , Figure 10 , Figure 15 and Figure 16 As shown in FIG. 1B, the gate layer 42B is disposed on the insulating layer 41B. The gate layer 42B is in conduction with the 2nd electrode 212 (gate electrode) of each switching element 20B via a linear connection member 51 (specifically, a gate line 511 described later). Figure 9 , Figure 10 , Figure 15 and Figure 16 As shown in FIG. 1B, the gate layer 42B is disposed on the insulating layer 41B. The gate layer 42B is in conduction with the 2nd electrode 212 (gate electrode) of each switching element 20B via a linear connection member 51 (specifically, a gate line 511 described later).

[0141] The pair of detection layers 43A, 43B have conductivity, and the constituent material thereof is, for example, Cu. The pair of detection layers 43A, 43B are each a band shape extending in the y direction, as shown in FIG. 1A and FIG. 1B. Figure 9 As shown in FIG. 1A, the detection layer 43A is disposed on the insulating layer 41A together with the gate layer 42A. The detection layer 43A is positioned in the vicinity of the gate layer 42A on the insulating layer 41A, and is separated from the gate layer 42A. The detection layer 43A is, for example, positioned closer to the side (x2 direction) on which the plurality of switching elements 20A are disposed than the gate layer 42A, but can be positioned on the opposite side. The detection layer 43A is in conduction with the 1st electrode 211 (source electrode) of each switching element 20A via a linear connection member 51 (specifically, a detection line 512 described later). Figure 9 , Figure 10 , Figure 15 and Figure 16 As shown in FIG. 1A, the detection layer 43A is disposed on the insulating layer 41A together with the gate layer 42A. The detection layer 43A is positioned in the vicinity of the gate layer 42A on the insulating layer 41A, and is separated from the gate layer 42A. The detection layer 43A is, for example, positioned closer to the side (x2 direction) on which the plurality of switching elements 20A are disposed than the gate layer 42A, but can be positioned on the opposite side. The detection layer 43A is in conduction with the 1st electrode 211 (source electrode) of each switching element 20A via a linear connection member 51 (specifically, a detection line 512 described later). Figure 9 , Figure 10 , Figure 15 and Figure 16As shown, the detection layer 43B is disposed on the insulating layer 41B together with the gate layer 42B. The detection layer 43B is located in the vicinity of the gate layer 42B on the insulating layer 41B and is separated from the gate layer 42B. The detection layer 43B is located, for example, closer to the side (x1 direction) on which the plurality of switching elements 20B are disposed than the gate layer 42B, but can be located on the opposite side. The detection layer 43B is connected to the first electrode 211 (source electrode) of each switching element 20B via a linear connection member 51 (specifically, a detection line 512) described later.

[0142] The plurality of stage bases 44 each have electrical insulation, and a material constituting the stage bases 44 is, for example, ceramic. As shown in Figure 7 and Figure 15 Each stage base 44 is joined to the surface of the conductive member 11A. Each stage base 44 is, for example, rectangular in plan view. The plurality of stage bases 44 are arranged side by side in the y direction and are separated from each other. The z-direction dimension of each stage base 44 is substantially the same as the sum of the z-direction dimension of the input terminal 31 and the z-direction dimension of the insulating member 39. Each stage base 44 has joined thereto each projection 321b of the pad portion 321 of the input terminal 32. Each stage base 44 supports the input terminal 32.

[0143] The plurality of linear connection members 51 are so-called bonding wires. The plurality of linear connection members 51 each have electrical conductivity, and a material constituting the linear connection members 51 is, for example, any one of Al (aluminum), Au (gold), and Cu. As shown in Figure 9 and Figure 10 The plurality of linear connection members 51 include a plurality of gate lines 511, a plurality of detection lines 512, a pair of first connection lines 513, and a pair of second connection lines 514.

[0144] As shown in Figure 9 and Figure 10 The plurality of gate lines 511 each have one end joined to the second electrode 212 (gate electrode) of the switching element 20 and the other end joined to any one of the pair of gate layers 42A and 42B. Among the plurality of gate lines 511, there are gate lines that connect the second electrode 212 of the switching element 20A to the gate layer 42A, and there are gate lines that connect the second electrode 212 of the switching element 20B to the gate layer 42B.

[0145] As shown in Figure 9 and Figure 10 The plurality of detection lines 512 each have one end joined to the first electrode 211 (source electrode) of the switching element 20 and the other end joined to any one of the pair of detection layers 43A and 43B. Among the plurality of detection lines 512, there are detection lines that connect the first electrode 211 of the switching element 20A to the detection layer 43A, and there are detection lines that connect the first electrode 211 of the switching element 20B to the detection layer 43B.

[0146] As Figure 9 and Figure 10 As shown, a pair of first connection lines 513 connect the gate layer 42A to the gate terminal 34A on one side and the gate layer 42B to the gate terminal 34B on the other side. One end of one first connection line 513 is engaged with the gate layer 42A, and the other end is engaged with the pad portion 341 of the gate terminal 34A, making them conductive. One end of the other first connection line 513 is engaged with the gate layer 42B, and the other end is engaged with the pad portion 341 of the gate terminal 34B, making them conductive.

[0147] like Figure 9 and Figure 10 As shown, a pair of second connecting lines 514 connect the detection layer 43A to the detection terminal 35A on one side and the detection layer 43B to the detection terminal 35B on the other side. One end of one second connecting line 514 is engaged with the detection layer 43A, and the other end is engaged with the pad portion 351 of the detection terminal 35A, making them conductive. One end of the other second connecting line 514 is engaged with the detection layer 43B, and the other end is engaged with the pad portion 351 of the detection terminal 35B, making them conductive.

[0148] Multiple plate-shaped connecting members 52 are each electrically conductive, and their constituent materials are, for example, any one of Al, Au, and Cu. Each plate-shaped connecting member 52 can be formed by folding plate-shaped metal sheets. Figure 7 , Figure 9 and Figure 10 As shown, the plurality of plate-shaped connecting members 52 include a plurality of first leads 521 and a plurality of second leads 522. Instead of the plurality of plate-shaped connecting members 52, bonding wires equivalent to the linear connecting members 51 described above may also be used.

[0149] like Figure 7 , Figure 9 and Figure 10 As shown, multiple first leads 521 connect the switching element 20A to the conductive member 11B. One end of each first lead 521 is connected to the first electrode 211 (source electrode) of the switching element 20A, and the other end is connected to the surface of the conductive member 11B.

[0150] like Figure 7 , Figure 9 and Figure 10 As shown, multiple second leads 522 connect each switching element 20B to the input terminal 32. One end of each second lead 522 is engaged with the first electrode 211 (source electrode) of each switching element 20B, and the other end is engaged with each protrusion 321b of the pad portion 321 of the input terminal 32. Each second lead 522 is joined, for example, using Ag paste or solder. Each second lead 522 is bent in the z-direction.

[0151] like Figure 15 and Figure 16 The sealing resin 60 covers the insulating substrate 10 (except for the back surface 102), the plurality of conductive members 11, the plurality of switching elements 20, the plurality of linear connecting members 51, and the plurality of plate-shaped connecting members 52, as shown. The constituent material of the sealing resin 60 is, for example, an epoxy resin. As shown in Figure 6 Figure 8 Figure 9 The sealing resin 60 has a resin front surface 61, a resin back surface 62, and a plurality of resin side surfaces 63, as shown. Figures 11-14 The resin front surface 61 and the resin back surface 62 are separated in the z direction, and face opposite sides of each other. The resin front surface 61 faces the z2 direction, and the resin back surface 62 faces the z1 direction. As shown in

[0152] The resin back surface 62 is in a frame shape that surrounds the back surface 102 of the insulating substrate 10 in a plan view, as shown. The plurality of resin side surfaces 63 are connected to both the resin front surface 61 and the resin back surface 62, and are sandwiched therebetween. Of the plurality of resin side surfaces 63, there are a pair of resin side surfaces 631, 632 that are separated in the x direction, and a pair of resin side surfaces 633, 634 that are separated in the y direction. The resin side surface 631 faces the x2 direction, and the resin side surface 632 faces the x1 direction. The resin side surface 633 faces the y2 direction, and the resin side surface 634 faces the y1 direction. Figure 12 As shown in

[0153] Figure 6 Figure 11 Figure 12 The sealing resin 60 includes a plurality of recessed portions 65 that are recessed in the z direction from the resin back surface 62, as shown. The plurality of recessed portions 65 each extend in the y direction, and are connected in a plan view from an end edge in the y1 direction to an end edge in the y2 direction of the resin back surface 62. The plurality of recessed portions 65 each form three in a plan view in the x direction sandwiching the back surface 102 of the insulating substrate 10. The plurality of recessed portions 65 can not be formed in the sealing resin 60.

[0154] The plurality of fused portions 93 are portions that join two metal members, and are the same structure as the respective fused portions 93 of the above-described joint structure Al (see Figure 1 Figure 2 ). The plurality of fused portions 93 include a plurality of output terminal joining portions 93A, a plurality of input terminal joining portions 93B, two side surface terminal joining portions 93C, 93D.

[0155] As shown in Figure 9 Figure 15 ​​​​​​​As shown in FIG. 9, the plurality of output terminal joining portions 93A are formed by laser welding of a portion of the output terminal 33 and a portion of the conductive member 1 IB which overlap in a plan view. The plurality of output terminal joining portions 93A are each formed in one of the comb tooth portions 331a in the pad portion 331 of the output terminal 33 in a plan view. The output terminal 33 as the first metal member 91 and the conductive member 1 IB as the second metal member 92 are joined by the output terminal joining portions 93A, and they constitute the joined structure A1.

[0156] As shown in FIG. 9, the plurality of output terminal joining portions 93A are formed by laser welding of a portion of the output terminal 33 and a portion of the conductive member 1 IB which overlap in a plan view. The plurality of output terminal joining portions 93A are each formed in one of the comb tooth portions 331a in the pad portion 331 of the output terminal 33 in a plan view. The output terminal 33 as the first metal member 91 and the conductive member 1 IB as the second metal member 92 are joined by the output terminal joining portions 93A, and they constitute the joined structure A1. Figure 9 Figure 15 As shown in FIG. 9, the plurality of input terminal joining portions 93B are formed by laser welding of a portion of the input terminal 31 and a portion of the conductive member 11A which overlap in a plan view. The plurality of input terminal joining portions 93B are each formed in one of the comb tooth portions 311a in the pad portion 311 of the input terminal 31 in a plan view. The input terminal 31 as the first metal member 91 and the conductive member 11A as the second metal member 92 are joined by the input terminal joining portions 93B, and they constitute the joined structure A1.

[0157] As shown in FIG. 9, the plurality of input terminal joining portions 93B are formed by laser welding of a portion of the input terminal 31 and a portion of the conductive member 11A which overlap in a plan view. The plurality of input terminal joining portions 93B are each formed in one of the comb tooth portions 311a in the pad portion 311 of the input terminal 31 in a plan view. The input terminal 31 as the first metal member 91 and the conductive member 11A as the second metal member 92 are joined by the input terminal joining portions 93B, and they constitute the joined structure A1. Figure 9 Figure 16 As shown in FIG. 9, the plurality of input terminal joining portions 93B are formed by laser welding of a portion of the input terminal 31 and a portion of the conductive member 11A which overlap in a plan view. The plurality of input terminal joining portions 93B are each formed in one of the comb tooth portions 311a in the pad portion 311 of the input terminal 31 in a plan view. The input terminal 31 as the first metal member 91 and the conductive member 11A as the second metal member 92 are joined by the input terminal joining portions 93B, and they constitute the joined structure A1.

[0158] As shown in FIG. 9, the plurality of input terminal joining portions 93B are formed by laser welding of a portion of the input terminal 31 and a portion of the conductive member 11A which overlap in a plan view. The plurality of input terminal joining portions 93B are each formed in one of the comb tooth portions 311a in the pad portion 311 of the input terminal 31 in a plan view. The input terminal 31 as the first metal member 91 and the conductive member 11A as the second metal member 92 are joined by the input terminal joining portions 93B, and they constitute the joined structure A1. Figure 9 Figure 16 As shown in FIG. 9, the plurality of input terminal joining portions 93B are formed by laser welding of a portion of the input terminal 31 and a portion of the conductive member 11A which overlap in a plan view. The plurality of input terminal joining portions 93B are each formed in one of the comb tooth portions 311a in the pad portion 311 of the input terminal 31 in a plan view. The input terminal 31 as the first metal member 91 and the conductive member 11A as the second metal member 92 are joined by the input terminal joining portions 93B, and they constitute the joined structure A1.

[0159] Next, the effects of the joined structure A1, the joining method, and the semiconductor device B1 according to the first embodiment will be described.

[0160] ​​​The joining structure A1 includes a welded portion 93. The welded portion 93 is formed by fusing a portion of the first metal member 91 and a portion of the second metal member 92 in the overlapping area of ​​the first metal member 91 and the second metal member 92. The welded portion 93 is formed, for example, by laser welding, to join the first metal member 91 and the second metal member 92. Therefore, the first metal member 91 and the second metal member 92 will not rub against each other. This helps to suppress surface damage to the first metal member 91 and the second metal member 92.

[0161] In the joining method of this embodiment, the laser performs a first scan along the first track T1, and simultaneously performs a second scan along the second track T2 from the reference position P3 of the first track T1. It is known that in laser welding, spatter can be suppressed by increasing the laser irradiation speed or decreasing the laser beam diameter. However, increasing the laser irradiation speed or decreasing the laser beam diameter may cause problems where the heat generated by the laser cannot be transferred from the first metal member 91 to the second metal member 92. As a result, the second metal member 92 may not melt, and the welded portion 93 cannot be formed across the first metal member 91 and the second metal member 92. This means that the first metal member 91 and the second metal member 92 are not joined. Therefore, by performing the aforementioned first and second scans, the laser trajectory is, for example... Figure 5 The trajectory is as shown. Therefore, even if the laser irradiation speed is increased and the laser beam diameter is reduced, the heat generated by the laser can be sufficiently transferred from the first metal member 91 to the second metal member 92. In summary, the joining method of this embodiment can suppress the occurrence of spatter during laser welding and join the first metal member 91 and the second metal member 92.

[0162] In the joining method of this embodiment, the radius R3 of the first track T1 is approximately the same as the radius R4 of the second track T2. For example, if the radius R3 of the first track T1 is different from the radius R4 of the second track T2, then in the laser trajectory (refer to...) Figure 5 In the plan view, it is impossible to pass through the central part (near the reference position P4 of the second track T2). Therefore, by making the radius R3 of the first track T1 approximately the same as the radius R4 of the second track T2, it is possible to... Figure 5 The laser trajectory shown is the trajectory that passes through the central part of the plan view.

[0163] Semiconductor device B1 includes multiple welded portions 93. That is, metal components with welded portions 93 are joined together by laser welding. Therefore, mutual friction between the metal components does not occur. In ultrasonic welding, the two joined metal components rub against each other, potentially generating dust due to wear. If this dust is generated during the manufacturing process of semiconductor device B1, it can cause malfunctions. Therefore, by using laser welding to join the two metal components, malfunctions of semiconductor device B1 can be suppressed. Furthermore, in the case of laser welding, there is a tendency for localized heat diffusion during welding. For example, when the pad portion 331 of output terminal 33 is joined to conductive member 11B by laser welding, the heat generated by the laser welding cannot diffuse to the conductive bonding layer 29 formed on conductive member 11B. Therefore, heat diffusion to the conductive bonding layer 29, etc., is suppressed. Therefore, during the manufacturing process of semiconductor device B1, unintentional melting of conductive bonding layer 29 and the like can be suppressed, thereby suppressing poor bonding of multiple switching elements 20.

[0164] In the semiconductor device B1, a plurality of welded portions 93 are formed by the bonding method described above. As described above, this bonding method can suppress the occurrence of spatter. If spatter occurs during the manufacturing process of the semiconductor device B1, it may become a cause of malfunction of the semiconductor device B1. Therefore, by forming a plurality of welded portions 93 using the bonding method described above, malfunction of the semiconductor device B1 can be suppressed.

[0165] In the semiconductor device B1, an insulating member 39 is provided between the terminal portion 312 of the input terminal 31 and the terminal portion 322 of the input terminal 32 in the z-direction. This allows the terminal portion 312 and the terminal portion 322 to be easily laminated into wiring.

[0166] like Figure 1 As shown, in the joining structure A1 according to the first embodiment, all of the radii of curvature of the plurality of linear marks 932 are the same, but this is not a limitation. For example, the radii of curvature of each linear mark 932 may be different. Figure 18 This is one example of such a variation. Figure 18 In the example shown, among a portion of multiple linear marks 932, the more located in the circumferential direction of the outer perimeter 931, the more pronounced the circumferential direction. Figure 18 (Clockwise), the radius of curvature gradually decreases. The minimum radius of curvature of the multiple linear marks 932 is, for example, approximately the same as the radius of curvature of the recess 933. It should be noted that the above-mentioned direction is consistent with the direction of movement of the second track T2. For example, such weld lines can be formed based on the ease of melting of the first metal component 91 and the second metal component 92, the degree of diffusion of heat generated by the laser, etc.

[0167] In the joining method according to the first embodiment, the case where the second track T2 is circular in plan view in the second scan is shown, but the second track T2 is not limited to this. For example, the reference position P3 can be moved linearly, can be moved curvilinearly, can be moved elliptically in plan view, or can be moved polygonally. Even in this case, the first scan is moved annularly with the reference position P3 as a reference. In the case where the reference position P3 is moved elliptically, the annular direction of the present disclosure is the direction in which the elliptical track is drawn. Furthermore, the second track T2 can be moved along not only one shape but also a plurality of shapes. Figure 19 For example, a case where linear movement and circular movement are combined is shown as an example. Figure 19 In the example shown, the reference position P3 of the first track T1 is moved linearly from the center position of the second track T2 (corresponding to the reference position P4) toward the second track T2 in the radial direction of the second track T2 (with reference to the third track T3). Then, the reference position P3 is moved along the second track T2 in the same manner as in the above example. As for the irradiated laser light, the control can be performed in the same manner as in the case where the peak powers are the same, or can be performed in the different manner as in the case where the peak powers are different, during the movement of the reference position P3 along the third track T3 and during the movement of the reference position P3 along the second track T2 for one cycle. In the case where a plurality of tracks are compounded in this manner to perform the second scan, the fusion portion 93 becomes Figure 20 a structure as shown. Figure 20 In the fusion portion 93 shown, the shape of the bottom portion 936 is different from that of the fusion portion 93 according to the first embodiment. Specifically, the cross section of the bottom portion 936 in the plane orthogonal to the thickness direction is not annular but circular. Such a Figure 20 In the case of the fusion portion 93 shown, the joining strength is improved, and at the same time, the low resistance due to the enlargement of the conduction path is also facilitated.

[0168] Next, the semiconductor device according to the second embodiment will be described with reference to Figures 21-24 The semiconductor device according to the second embodiment will be described. Note that, in the following description, the same symbols are attached to elements common to or similar to those of the first embodiment, and the description thereof is omitted.

[0169] The semiconductor device B2 according to the second embodiment is different from the semiconductor device Bl in the following points. The points are that the bus bar Cl is further provided, and that the plurality of fusion portions 93 further include the plurality of supply terminal joining portions 93E and the plurality of supply terminal joining portions 93F. The semiconductor device B2 includes the semiconductor device Bl and the bus bar Cl connected to the semiconductor device Bl via the plurality of supply terminal joining portions 93E and the plurality of supply terminal joining portions 93F. Figure 21 A perspective view of the semiconductor device B2 is shown. Figure 22This is a plan view of semiconductor device B2. Figure 23 This is a bottom view of semiconductor device B2. Figure 24 For along Figure 22 A cross-sectional view of the XXIV-XXIV line.

[0170] like Figures 21-24 As shown, bus C1 has two supply terminals 71 and 72, an insulator 73, and a molding resin 74.

[0171] The two supply terminals 71 and 72 are metal plates. The material of these metal plates is, for example, Cu or a Cu alloy. Figures 21-24 As shown, each supply terminal 71, 72 is a strip extending in the x-direction. The supply terminal 72 is disposed separately from the supply terminal 71 on the main surface 101 side of the insulating substrate 10 facing the z-direction. In the plan view, the supply terminal 72 overlaps with the supply terminal 71. Figures 22-24 In the example shown, the shape of supply terminal 71 is the same as that of supply terminal 72. The z-direction dimension of each supply terminal 71 and 72 is, for example, 0.8 mm, but is not limited thereto.

[0172] like Figure 24 As shown, the supply terminal 71 is joined to the input terminal 31 by laser welding and is electrically connected to the input terminal 31. The supply terminal 71 includes a base 711 and a plurality of protrusions 712 at its front end exposed from the mold resin 74. The plurality of protrusions 712 extend from the base 711 in the x1 direction. Each protrusion 712 is rectangular in plan view. This embodiment includes two protrusions 712. The two protrusions 712 are arranged with a gap in the y direction. Thus, the aforementioned front end of the supply terminal 71 is concave. It should be noted that the shape of the supply terminal 71 is not limited to the above case; for example, the portion exposed from the mold resin 74 may be rectangular in plan view.

[0173] Supply terminal 72 such Figure 24 The supply terminal 72 is connected to the input terminal 32 via laser welding, thus establishing electrical connection with the input terminal 32. The supply terminal 72 includes a base 721 and multiple protrusions 722 at its front end exposed from the mold resin 74. The multiple protrusions 722 extend from the base 721 in the x1 direction. Each protrusion 722 is rectangular in plan view. In this embodiment, there are two protrusions 722. The two protrusions 722 are arranged with a gap in the y-direction. Therefore, the front end of the supply terminal 72 is concave. It should be noted that the shape of the supply terminal 72 is not limited to the above-described case; for example, the portion exposed from the mold resin 74 may be rectangular in plan view.

[0174] Insulator 73, etc. Figure 24The supply terminals 71, 72 are sandwiched in the z direction as shown. The insulator 73 has electrical insulation, and as an example of a material constituting the same, a synthetic resin such as glass epoxy resin. The surface of the supply terminal 71 facing the z2 direction is in contact with the insulator 73. The surface of the supply terminal 72 facing the zl direction is in contact with the insulator 73. The supply terminal 71 and the supply terminal 72 constitute a laminated wiring in which they overlap each other in a plan view and are electrically insulated from each other by the insulator 73.

[0175] As shown in Figure 24 , the mold resin 74 covers a portion of each of the supply terminals 71, 72 and the insulator 73. The material constituting the mold resin 74 is a synthetic resin having electrical insulation such as epoxy resin. A portion of each of the supply terminals 71, 72 and the insulator 73 protrudes from both sides in the x direction of the mold resin 74. Note that the bus bar Cl can not be provided with the mold resin 74.

[0176] As shown in Figure 23 and Figure 24 , the plurality of supply terminal joining portions 93E are formed by laser welding of a portion of the supply terminal 71 and a portion of the input terminal 31 which overlap each other in a plan view. Through the supply terminal joining portions 93E, the supply terminal 71 as the first metal member 91 is joined to the input terminal 31 as the second metal member 92, and they constitute the joined structure Al. Figure 23 In the example shown, there are three supply terminal joining portions 93E, but the number of the supply terminal joining portions 93E is not particularly limited. In the joined structure Al provided with the supply terminal joining portions 93E, the second metal member 92 is thinner than each of the joined structures Al related to the first embodiment described above.

[0177] As shown in Figure 23 , of the plurality of supply terminal joining portions 93E, the supply terminal joining portion 93E formed in the protruding portion 712 of the supply terminal 71 has a larger radius (corresponding to the radius of the outer periphery 931 described above) in a plan view than the supply terminal joining portion 93E formed in the base portion 711 of the supply terminal 71. This is due to the fact that the width (dimension in the y direction) of the protruding portion 712 is narrower than the width (dimension in the y direction) of the base portion 711. In detail, the width of the protruding portion 712 is narrower than the width of the base portion 711, and thus heat generated at the time of laser welding is difficult to release. As a result, the molten bath generated becomes larger, and thus the diameter of the supply terminal joining portion 93E formed in the protruding portion 712 becomes larger. In consideration of such a tendency, it is possible to make the radii of each of the supply terminal joining portions 93E in a plan view substantially the same by adjusting various conditions of laser welding (for example, the peak power of laser).

[0178] As shown in Figures 21-22 and Figure 24As shown, multiple supply terminal joints 93F are formed by laser welding a portion of a supply terminal 72 that overlaps in the plan view with a portion of an input terminal 32. Through each supply terminal joint 93F, the supply terminal 72, which serves as a first metal member 91, joins with the input terminal 32, which serves as a second metal member 92, forming a joint structure A1. In this embodiment, there are three supply terminal joints 93F. Figure 22 In the example shown, the number of supply terminal joints 93F is not particularly limited. In the joint structure A1 having each supply terminal joint 93F, the second metal member 92 is thinner than the joint structure A1 according to the first embodiment described above.

[0179] like Figure 22 As shown, among the multiple supply terminal joints 93F, the radius of the supply terminal joint 93F formed in the protrusion 722 of the supply terminal 72 in the plan view (corresponding to the radius of the outer perimeter 931 mentioned above) is larger than that of the supply terminal joint 93F formed in the base 721 of the supply terminal 72. This is because the width (y-direction dimension) of the protrusion 722 is narrower than the width (y-direction dimension) of the base 721. Specifically, since the width of the protrusion 722 is narrower than the width of the base 721, the heat generated during laser welding is difficult to dissipate. As a result, the generated molten bath becomes larger, and therefore the diameter of the supply terminal joint 93F formed in the protrusion 722 becomes larger. Considering this tendency, the radii of each supply terminal joint 93F in the plan view can be made substantially the same by adjusting various conditions of laser welding (e.g., the peak power of the laser).

[0180] In semiconductor device B2, supply terminal 71 is the positive terminal and supply terminal 72 is the negative terminal. The two supply terminals 71 and 72 are, for example... Figure 24 As shown, it is connected to a DC power supply on the x2 side. Thus, the DC power supply voltage is applied between the two input terminals 31 and 32 via bus C1.

[0181] Next, the effects of the semiconductor device B2 according to the second embodiment will be explained.

[0182] Semiconductor device B2 includes multiple welded portions 93. That is, similar to the first embodiment described above, metal components with welded portions 93 are joined together by laser welding. Therefore, the two metal components do not rub against each other, thus suppressing dust generation. This helps to prevent malfunctions in semiconductor device B2. Furthermore, since the welded portions 93 are formed using the aforementioned joining method, spattering is suppressed. This further helps to prevent malfunctions in semiconductor device B2.

[0183] Semiconductor device B2 includes input terminal 31 and input terminal 32. Input terminal 31 has a terminal portion 312. Input terminal 32 has a terminal portion 322. Furthermore, semiconductor device B2 includes bus C1. Bus C1 includes two supply terminals 71 and 72. The terminal portion 322 of input terminal 32 is separate from the terminal portion 312 of input terminal 31 in the z-direction, and overlaps with the terminal portion 312 of input terminal 31 in a plan view. Supply terminal 72 is separate from supply terminal 71 in the z-direction, and overlaps with supply terminal 71 in a plan view. Supply terminal 71 and the terminal portion 312 of input terminal 31 are joined by multiple supply terminal joints 93E, and supply terminal 72 and the terminal portion 322 of input terminal 32 are joined by multiple supply terminal joints 93F. Thus, the terminal portion 312 and supply terminal 71, and the terminal portion 322 and supply terminal 72 constitute a continuous laminated wiring. Therefore, the power supplied from the DC power supply to the semiconductor device B2 passes through the laminated wiring. Thus, this laminated wiring allows for a more stable reduction in the inductance generated inside the semiconductor device B2. Therefore, by utilizing the semiconductor device B2, the internal inductance can be reduced in a more stable state.

[0184] In the semiconductor device B2, the bus C1 includes an insulator 73 sandwiched between two supply terminals 71 and 72 in the z-direction. This allows the supply terminals 71 and 72 to be easily configured as laminated wiring.

[0185] In semiconductor device B2, supply terminal 71 and input terminal 31 are joined by three supply terminal joints 93E. These three supply terminal joints 93E are formed by laser welding based on the aforementioned joining method. Increasing the number of supply terminal joints 93E can further improve the bonding strength between supply terminal 71 and input terminal 31, but this increases the number of laser welding operations, thus increasing the workload of the manufacturing process. Furthermore, supply terminal 71 may undergo thermal deformation due to the heat generated by laser welding. Therefore, to reduce the workload of the manufacturing process and minimize the impact of thermal deformation, it is preferable to join supply terminal 71 and input terminal 31 using three supply terminal joints 93E. It should be noted that supply terminal 72 and input terminal 32 are joined by three supply terminal joints 93F for the same reason.

[0186] In semiconductor device B2, bus C1 includes a supply terminal 71. The supply terminal 71 includes a base 711 and multiple extensions 712 extending from the base 711. For example... Figure 23 As shown, in supply terminal 71, the portion that engages with input terminal 31 is divided into two parts. Therefore, when engaging using three supply terminal engagement portions 93E as described above, the effects of thermal deformation can be further reduced. In supply terminal 72, as... Figure 22The reason why the portion shown as being joined with the input terminal 32 is divided into two is also for this reason.

[0187] In the second embodiment, as shown in Figure 24 DC is connected between the two supply terminals 71, 72, but is not limited thereto. For example, as shown in Figure 25 A capacitor C can be further connected. The capacitor C is connected in parallel with the DC power supply DC. The capacitor C is a ceramic capacitor, a film capacitor, or the like. The capacitor C functions to accumulate electric charges of the counter electromotive force generated as a factor of inductance at the two input terminals 31, 32 due to the driving of the plurality of switching elements 20 of the semiconductor device B2. Therefore, Figure 25 In the manner shown in Figure 26 A series circuit of the capacitor C and a resistor R can be further connected. The series circuit is a so-called RC snubber circuit, and is connected in parallel with the DC power supply DC. The resistor R can lower the voltage of the counter electromotive force generated at the two input terminals 31, 32. Therefore, Figure 26 In the manner shown in

[0188] Figure 27 A semiconductor device according to the third embodiment is shown. The semiconductor device B3 of the third embodiment is different from the semiconductor device Bl in the shape of the sealing resin 60. Other than this, it is the same as the semiconductor device Bl. Figure 27 A perspective view of the semiconductor device B3 is shown.

[0189] The sealing resin 60 of the present embodiment protrudes in the x direction at each end edge portion in the y direction in a plan view. A portion of each of the two input terminals 31, 32 and the insulating member 39 is covered by the portion of the sealing resin 60 extending in the x2 direction. Further, a portion of the output terminal 33 is covered by the portion of the sealing resin 60 extending in the xi direction.

[0190] The semiconductor device B3 is larger than the semiconductor device Bl in the sealing resin 60, and further covers a portion of each of the two input terminals 31, 32, the output terminal 33, and the insulating member 39. Thus, the semiconductor device B3 is more capable than the semiconductor device Bl of protecting the two input terminals 31, 32, the output terminal 33, and the insulating member 39 from deterioration, bending, and the like.

[0191] The bus bar Cl shown in the second embodiment can also be connected in the semiconductor device B3.

[0192] In the joining structure A1 described above, the case where the surfaces of the first metal member 91 and the second metal member 92 are Cu is given, but is not limited thereto. For example, the surface of either one or both of the first metal member 91 and the second metal member 92 can be covered with a metal plating layer. As the metal plating layer, for example, Sn, Ni (nickel), or the like is given. Hereinafter, the case where either one of the first metal member 91 or the second metal member 92 is covered with a metal plating layer will be described. Note that the melting point of Cu is 1085°C, the melting point of Sn is 232°C, and the melting point of Ni is 1453°C.

[0193] Figures 28-32 are diagrams for describing the joining structure (welding portion 93) in the modified example. Each welding portion 93 shown in these diagrams can be formed by performing only the first scanning described above (without performing the second scanning described above). Figures 28-32 is a cross-sectional schematic view of each joining structure.

[0194] Figure 28 is an example of a case where neither the surface of the first metal member 91 nor the surface of the second metal member 92 is plated. Figure 28 Corresponding to the joining structure A1, is shown for comparison with the example illustrated in the modified example Figures 29-32 . Figure 29 is an example of a case where the first metal member 91 is not covered with a metal plating layer, and the second metal member 92 is covered with a Sn plating layer. Figure 30 is an example of a case where the first metal member 91 is not covered with a metal plating layer, and the second metal member 92 is covered with a Ni plating layer. Figure 31 is an example of a case where the first metal member 91 is covered with a Sn plating layer, and the second metal member 92 is not covered with a metal plating layer. Figure 32 is an example of a case where the first metal member 91 is covered with a Ni plating layer, and the second metal member 92 is not covered with a metal plating layer.

[0195] As shown in Figure 29 and Figure 31 , in the case where either the first metal member 91 or the second metal member 92 is covered with a Sn plating layer, the welding portion 93 bulges to the side near the interface between the first metal member 91 and the second metal member 92. This is because the melting point of Sn is lower than that of Cu, and thus Sn melts more easily than Cu due to heat caused by laser light. In addition, a part of the welding portion 93 is composed of a CuSn alloy.

[0196] On the other hand, as shown in Figure 30 and Figure 32 , in the case where either the first metal member 91 or the second metal member 92 is covered with a Ni plating layer, the welding portion 93 does not bulge to the side Figure 29 and Figure 31 The bulging of the fusion portion 93 in the vicinity of the interface between the first metal member 91 and the second metal member 92 as shown. Furthermore, the fusion portion 93 does not contain CuNi alloy in its composition, and Cu and Ni coexist respectively.

[0197] Even in the case where either one or both of the first metal member 91 and the second metal member 92 is subjected to metal plating (refer to Figures 29-32 ), the joining strength of the first metal member 91 and the second metal member 92 is also substantially equivalent compared to the case where metal plating is not performed (refer to Figure 28 ). Furthermore, the electrical conductivity in each fusion portion 93 is also substantially equivalent. That is, in the joining structure of the present disclosure, metal plating can be appropriately performed on the first metal member 91 and the second metal member 92.

[0198] The joining structure, the semiconductor device, and the joining method according to the present disclosure are not limited by the above-described embodiments. The specific configurations of each part of the joining structure and the semiconductor device of the present disclosure, and the specific processes of each step of the joining method of the present disclosure can be freely subjected to various design changes.

Claims

1. A semiconductor device comprising: first and second semiconductor elements (20A, 20B) having a first electrode and a control electrode formed on a surface side, and a second electrode formed on a back surface side, performing switching between the first electrode and the second electrode in response to a signal input to the control electrode, a first conductive member (11A) electrically connected to the second electrode of the first semiconductor element (20A), a second conductive member (11B) electrically connected to the second electrode of the second semiconductor element (20B), a first terminal (31) partially overlapping the first conductive member when viewed from a first direction, and being in conductive junction with the first conductive member at the overlapping portion, and a second terminal (32) electrically connected to the first electrode (211) of the second semiconductor element (20B); the first terminal includes a first terminal portion (312), the second terminal includes a second terminal portion (322), the conductive junction includes a fusion portion in which a portion of the first terminal and a portion of the first conductive member are fused, and the fusion portion is fused to an intermediate depth of the first conductive member.

2. The semiconductor device according to claim 1, wherein the second conductive member is electrically connected to a surface electrode of the first semiconductor element (20A).

3. The semiconductor device according to claim 1, further comprising a third terminal (33) in conductive junction with the second conductive member.

4. The semiconductor device according to claim 1, further comprising an insulating layer (41) disposed on surfaces of the first and second conductive members, and a wiring layer (42, 43) formed on the insulating layer.

5. The semiconductor device according to claim 1, comprising a sealing resin (60) covering the first and second semiconductor elements, terminal portions other than the first and second terminal portions, and the fusion portion.

6. The semiconductor device according to claim 5, wherein a rough surface region is formed on a surface of the first terminal and / or the first conductive member that is in contact with the sealing resin.

7. The semiconductor device according to claim 1, further comprising an insulating substrate (10) on which the first and second conductive members are mounted.

8. The semiconductor device according to claim 1, wherein the conductive junction is laser fusion, a surface of the fusion portion is uneven, and has a portion that protrudes more than a surface of the first terminal.

9. The semiconductor device according to claim 1, wherein the first terminal portion and the second terminal portion partially overlap when viewed from the first direction.

10. The semiconductor device according to claim 1, comprising an insulating member (39) sandwiched between the first terminal portion and the second terminal portion.

11. The semiconductor device according to claim 1, wherein a plurality of the first semiconductor elements are connected in parallel, and a plurality of the second semiconductor elements are connected in parallel.

12. The semiconductor device according to claim 1, wherein the fusion portion further includes a notch portion that is circular when viewed from the first direction. ​ ​ ​ ​ ​ ​ ​ ​ ​ The diameter of the pocket portion (933) is smaller than the radius of the outer periphery (931).

13. The semiconductor device according to claim 1, wherein the fusion portion (93) includes a bottom portion (936) that overlaps the second metal member (92) when viewed in a second direction orthogonal to the first direction.

14. The semiconductor device according to claim 1, wherein the fusion portion includes a first joining portion (93B) formed so as to span from the first terminal (31) to the first conductive member (11A).

15. The semiconductor device according to claim 3, wherein the fusion portion includes a second joining portion (93A) formed so as to span from the third terminal (33) to the second conductive member (11B).

16. The semiconductor device according to claim 1, wherein the depth of the fusion portion in the first conductive member is shallower than the thickness of the first terminal.

17. A semiconductor device comprising: a first semiconductor element (20A) having a first electrode and a control electrode formed on a front surface side, and a second electrode formed on a back surface side, performing switching between the first electrode and the second electrode in accordance with a signal input to the control electrode, a first conductive member (11A) electrically connected to the second electrode of the first semiconductor element (20A), and a first terminal (31) partially overlapping the first conductive member when viewed in a first direction, and being in conductive junction with the first conductive member at a portion of the overlapping portion; wherein the conductive junction includes a fusion portion in which a portion of each of the first terminal and the first conductive member is fused, the first terminal includes a first terminal portion (312), and the fusion portion is fused to an intermediate depth of the first conductive member.

18. The semiconductor device according to claim 17, further comprising a second terminal (32) including a second terminal portion, and partially overlapping the first terminal when viewed in the first direction, with an insulating member (39) interposed between the first terminal portion and the second terminal portion.

19. The semiconductor device according to claim 17, further comprising an insulating layer (41) disposed on a surface of the first conductive member, and a wiring layer (42, 43) formed on the insulating layer.

20. The semiconductor device according to claim 17, further comprising an insulating substrate (10) on which the first conductive member is mounted.

21. The semiconductor device according to claim 17, wherein the conductive junction is laser fusion, and a surface of the fusion portion is uneven, having a portion that protrudes more than a surface of the first terminal.

22. The semiconductor device according to claim 17, wherein a plurality of the first semiconductor elements are connected in parallel. ​ ​ ​ ​ ​ ​

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