Semiconductor Module

Abstract

To suppress the occurrence of electrical defects.SOLUTION: Between a first insulating sheet 23 and a second power terminal 25, a thermally anisotropic sheet 24 having higher thermal conductivity in the planar direction perpendicular to the lamination direction than in the lamination direction of a terminal lamination portion is provided. As a result, when a connecting member 40 is joined to the front surface of the second power terminal 25 by laser welding, conduction of heat to the first insulating sheet 23 due to the laser can be suppressed. Therefore, the first insulating sheet 23 can be prevented from being damaged, and the insulation between the first power terminal 22 and the second power terminal 25 is maintained.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a semiconductor module. [Background technology]

[0002] The semiconductor device has a semiconductor module and a capacitor. The semiconductor module and the capacitor are electrically connected. The semiconductor module includes a power device and has, for example, a power conversion function. The power device is, for example, an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). In such a semiconductor device, the P terminal and N terminal of the semiconductor module are connected to the P terminal and N terminal of the capacitor by a bus bar. Furthermore, insulating paper is provided between the P terminal and the N terminal to maintain insulation between the P terminal and the N terminal. The P terminal, N terminal, and bus bar are connected by laser welding (see, for example, Patent Document 1).

[0003] Furthermore, when joining the P terminal, N terminal, and bus bar by laser welding, the welded portion may melt excessively due to the heat of the laser. To prevent this, a heat transfer probe is pressed against the vicinity of the welded portion. The heat transfer probe extracts the heat generated during welding, suppressing excessive temperature rise in the welded portion and preventing melting (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-106235 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-190067 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, a semiconductor module has insulating paper between the P terminal and the N terminal. When a bus bar is laser-welded to the P terminal and the N terminal with the insulating paper sandwiched between them, the insulating paper may be damaged by heat from the laser. If the insulating paper is damaged, the insulation between the P terminal and the N terminal cannot be maintained. This may result in electrical defects and reduce the reliability of the semiconductor module and the semiconductor device including the semiconductor module.

[0006] The present invention has been made in view of the above points, and has an object to provide a semiconductor module in which the occurrence of electrical defects is suppressed. [Means for solving the problem]

[0007] According to one aspect of the present invention, a semiconductor module is provided, which has a terminal stack portion in which a first terminal, an insulating member, and a second terminal are stacked in this order, and a thermally anisotropic member is provided between the insulating member and the second terminal, the thermal conductivity of which is higher in a planar direction perpendicular to the stacking direction of the terminal stack portion than in the stacking direction of the terminal stack portion. [Effects of the Invention]

[0008] According to the disclosed technology, the occurrence of electrical defects is suppressed, and a decrease in reliability is prevented. [Brief explanation of the drawings]

[0009] [Figure 1] 1 illustrates a semiconductor device according to a first embodiment. [Figure 2] 1 illustrates a semiconductor module according to a first embodiment. [Figure 3] 2 is a plan view of a terminal stacking portion of the semiconductor module according to the first embodiment; FIG. [Figure 4] 2 is an equivalent circuit of a semiconductor module of the semiconductor device according to the first embodiment. [Figure 5] 1 shows a capacitor according to a first embodiment. [Figure 6]2 is a cross-sectional view showing a connection mechanism included in the semiconductor device of the first embodiment. FIG. [Figure 7] 1 is a cross-sectional view (part 1) illustrating a connection method of the semiconductor device according to the first embodiment; [Figure 8] FIG. 2 is a cross-sectional view (part 2) for explaining the connection method of the semiconductor device according to the first embodiment. [Figure 9] 10 is a graph showing the thermal conductivity and the instantaneous maximum temperature of the insulating sheet according to the thickness of the thermally anisotropic sheet included in the semiconductor module of the first embodiment. [Figure 10] 10 is a graph showing the thermal conductivity and the instantaneous maximum temperature of the thermal anisotropic sheet according to the thickness of the thermal anisotropic sheet included in the semiconductor module of the first embodiment. [Figure 11] 4A and 4B are diagrams illustrating an analysis of heat generated by laser welding in the semiconductor device according to the first embodiment. [Figure 12] FIG. 10 is a cross-sectional view of a connection portion of a semiconductor module according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described with reference to the drawings. In the following description, the terms "front surface" and "upper surface" refer to the XY plane facing upward (+Z direction) in the semiconductor device 10 of FIG. 1. Similarly, "up" refers to the upward direction (+Z direction) in the semiconductor device 10 of FIG. 1. The terms "back surface" and "lower surface" refer to the XY plane facing downward (-Z direction) in the semiconductor device 10 of FIG. 1. Similarly, "lower" refers to the downward direction (-Z direction) in the semiconductor device 10 of FIG. 1. Similar directions will be used in other drawings as necessary. The terms "higher" refer to the upper side (+Z side) in the semiconductor device 10 of FIG. 1. Similarly, the terms "lower" refer to the lower side (-Z side) in the semiconductor device 10 of FIG. 1. The terms "front surface," "upper surface," "upper," "back surface," "lower surface," "lower," and "side" are merely convenient expressions for specifying relative positional relationships and do not limit the technical concept of the present invention. For example, "up" and "down" do not necessarily refer to the vertical direction relative to the ground. In other words, the "up" and "down" directions are not limited to the direction of gravity. In the following description, "main component" refers to a component containing 80 vol% or more of a substance.

[0011] [First embodiment] A semiconductor device according to a first embodiment will be described with reference to FIG. 1. FIG. 1 illustrates the semiconductor device according to the first embodiment. The semiconductor device 10 includes a semiconductor module 20 and a capacitor 30. The semiconductor module 20 and the capacitor 30 are positioned as close as possible to each other with their sides facing each other. Connecting members 40a, 40b, and 40c electrically and mechanically connect the semiconductor module 20 and the capacitor 30. The connecting members 40a, 40b, and 40c have linear laser weld marks 44a and 44b on the capacitor 30 side and the semiconductor module 20 side, respectively. The number and width of the connecting members 40a, 40b, and 40c are merely examples. The number and width of the connecting members 40a, 40b, and 40c are selected depending on the number and width of terminal stacked portions 26a, 26b, and 26c (described later) included in the semiconductor module 20. Hereinafter, the connecting members 40a, 40b, 40c and the terminal stacking portions 26a, 26b, 26c will be described as the connecting member 40 and the terminal stacking portion 26, as needed, unless otherwise distinguished.

[0012] Next, the semiconductor module 20 included in the semiconductor device 10 will be described with reference to FIGS. 2 to 4. FIG. 2 shows the semiconductor module of the first embodiment, and FIG. 3 is a plan view of a terminal stack of the semiconductor module of the first embodiment. FIG. 4 is an equivalent circuit of the semiconductor module of the semiconductor device of the first embodiment. Note that FIG. 3 shows a plan view of the terminal stack 26a (first power terminal 22a, first insulating sheet 23a, second power terminal 25a) of the semiconductor module 20, with the case 21 indicated by a dashed line. Also, FIG. 3 only shows the terminal stack 26a; terminal stacks 26b and 26c are also shown in the same manner.

[0013] The semiconductor module 20 includes a semiconductor unit (not shown) and a case 21 that houses the semiconductor unit. The semiconductor unit includes an insulating circuit board and a semiconductor chip mounted on the insulating circuit board. The insulating circuit board includes an insulating plate, a heat sink formed on the back surface of the insulating plate, and a circuit pattern formed on the front surface of the insulating plate. The insulating plate is made of ceramics with excellent thermal conductivity. Examples of such ceramics include aluminum oxide, aluminum nitride, and silicon nitride, which have high thermal conductivity. The heat sink is made of a metal with excellent thermal conductivity. Examples of such metals include aluminum, iron, silver, copper, or an alloy containing at least one of these. The circuit pattern is made of a metal with excellent electrical conductivity. Examples of such metals include copper or a copper alloy. The number and shape of the circuit pattern are selected appropriately depending on the specifications of the semiconductor module 20. Examples of ceramic circuit boards with such a configuration include direct copper bonding (DCB) substrates and active metal brazed (AMB) substrates.

[0014] The semiconductor chip includes a switching element such as an IGBT or a power MOSFET, which is made of silicon, silicon carbide, or gallium nitride. Such a semiconductor chip includes, for example, a drain electrode (or collector electrode) as a main electrode on the back surface and a gate electrode and a source electrode (or emitter electrode) as main electrodes on the front surface. The semiconductor chip also includes, as necessary, a free-wheeling diode (FWD) such as a Schottky barrier diode (SBD) or a P-intrinsic-N (PiN) diode. Such a semiconductor chip includes a cathode electrode as a main electrode on the back surface and an anode electrode as a main electrode on the front surface. Alternatively, a reverse-conducting (RC) IGBT, which combines the functions of an IGBT and an FWD, may be used as the semiconductor chip. The number and type of such semiconductor chips are also appropriately selected according to the specifications of the semiconductor module 20.

[0015] Case 21 has a generally rectangular shape in a plan view and is surrounded on all four sides by first to fourth side portions 21a to 21d. Case 21 includes storage areas 21e1, 21e2, and 21e3 along first side portion 21a. Case 21 also includes first power terminals 22a, 22b, and 22c, first insulating sheets 23a, 23b, and 23c, a thermally anisotropic sheet 24 (see FIGS. 3 and 6), and second power terminals 25a, 25b, and 25c. Case 21 also includes U-terminal 28a, V-terminal 28b, and W-terminal 28c. Note that FIG. 3 merely illustrates the case where thermally anisotropic sheet 24 is disposed on first insulating sheet 23a. Thermally anisotropic sheet 24 is disposed on each of first insulating sheets 23a, 23b, and 23c.

[0016] Such case 21 is formed by injection molding using a thermoplastic resin. Control terminals 27a, 27b, and 27c are attached to case 21 in storage areas 21e1, 21e2, and 21e3 parallel to the short sides (second and fourth sides 21b and 21d) of case 21. Examples of thermoplastic resin include polyphenylene sulfide (PPS), polybutylene terephthalate (PBT) resin, polybutylene succinate (PBS) resin, polyamide (PA) resin, and acrylonitrile butadiene styrene (ABS) resin.

[0017] Control terminals 27a, 27b, and 27c are also formed by injection molding using a thermoplastic resin and include predetermined terminals. Note that, unless otherwise specified, storage areas 21e1, 21e2, and 21e3, first power terminals 22a, 22b, and 22c, and second power terminals 25a, 25b, and 25c will be referred to as storage area 21e, first power terminal 22, and second power terminal 25. Similarly, first insulating sheets 23a, 23b, and 23c (described later) will be referred to as first insulating sheet 23.

[0018] Storage areas 21e1, 21e2, and 21e3 are spaces partitioned by control terminals 27a and 27b in the middle of case 21 in a plan view, and are provided along the longitudinal direction (first and third side portions 21a and 21c) of case 21. Storage areas 21e1, 21e2, and 21e3 each store the semiconductor units described above. Within storage areas 21e1, 21e2, and 21e3, the semiconductor units are electrically connected to first power terminals 22a, 22b, and 22c, second power terminals 25a, 25b, and 25c, U-terminal 28a, V-terminal 28b, and W-terminal 28c, respectively. The semiconductor units are also electrically connected to control terminals 27a, 27b, and 27c. For this electrical connection, wiring members (e.g., bonding wires or lead frames) are used. The wiring members are made of a material with excellent conductivity. Such a material is a metal (for example, aluminum or copper), or an alloy containing at least one of these.

[0019] When the semiconductor units are stored in the storage areas 21e1, 21e2, and 21e3 in this manner, the interiors are sealed with a sealing resin, as shown in FIG. 2. The sealing material contains a thermosetting resin and a filler contained in the thermosetting resin. The thermosetting resin is an epoxy resin, a phenolic resin, a maleimide resin, or the like. The filler is silicon oxide, aluminum oxide, boron nitride, or aluminum nitride.

[0020] One end of the front surface of each of the first power terminals 22a, 22b, and 22c is exposed in the terminal areas 21a1, 21a2, and 21a3 of the first side portion 21a of the case 21 along the longitudinal direction (first side portion 21a). Here, one end of each of the first power terminals 22a, 22b, and 22c protrudes outward (in the -X direction) from the first side portion 21a. The other end of each of the first power terminals 22a, 22b, and 22c is electrically connected to a location corresponding to the N terminal of the semiconductor chip inside the case 21. At least the first side portion 21a side of each of the first power terminals 22a, 22b, and 22c has a flat plate shape. The first power terminals 22a, 22b, and 22c are made of a metal with excellent conductivity. Such a metal is, for example, copper or a copper alloy.

[0021] The second power terminals 25a, 25b, and 25c are disposed on the first power terminals 22a, 22b, and 22c with the first insulating sheets 23a, 23b, and 23c sandwiched therebetween, with one end of the first power terminals 22a, 22b, and 22c exposed. The leading ends (terrace portions 29a, 29b, and 29c) of the first insulating sheets 23a, 23b, and 23c are positioned between the leading ends of the first power terminals 22a, 22b, and 22c and the leading ends of the second power terminals 25a, 25b, and 25c. This maintains insulation between the first power terminals 22a, 22b, and 22c and the second power terminals 25a, 25b, and 25c.

[0022] The first insulating sheets 23a, 23b, and 23c are made of an insulating material. Examples of such insulating materials include insulating paper made of a wholly aromatic polyamide polymer, and sheets made of a fluorine-based or polyimide-based resin material. The terrace portions 29a, 29b, and 29c will be referred to as the terrace portion 29 unless otherwise specified.

[0023] The thermally anisotropic sheet 24 is made of a material having a higher thermal conductivity in a planar direction (direction along the XY plane) perpendicular to the stacking direction of the terminal stack portions 26a, 26b, and 26c than in the stacking direction (±Z direction). Such a material may be primarily composed of graphite, for example. The thermally anisotropic sheet 24 is disposed at least in the area indicated by the dotted line in FIG. 3. That is, in plan view, the thermally anisotropic sheet 24 does not protrude from the second power terminals 25a, 25b, and 25c, but is provided below the exposed areas of the second power terminals 25a, 25b, and 25c. Details of the thermally anisotropic sheet 24 will be described later.

[0024] One end of the front surface of each of the second power terminals 25a, 25b, and 25c is exposed on the first side 21a of the case 21 along the longitudinal direction (first side 21a). The exposed portions of the one end of each of the second power terminals 25a, 25b, and 25c overlap the thermally anisotropic sheet 24 in a plan view. The other end of each of the second power terminals 25a, 25b, and 25c is electrically connected to a location corresponding to a P terminal of the semiconductor chip inside the case 21. At least the second power terminals 25a, 25b, and 25c on the first side 21a side are flat. The second power terminals 25a, 25b, and 25c are made of a metal with excellent conductivity. Such a metal is, for example, copper or a copper alloy.

[0025] In this manner, the first power terminals 22a, 22b, and 22c, the first insulating sheets 23a, 23b, and 23c, the thermally anisotropic sheet 24, and the second power terminals 25a, 25b, and 25c are stacked in this order to form terminal stacked portions 26a, 26b, and 26c. In this configuration, the edge regions of the front surfaces of the first power terminals 22a, 22b, and 22c, the first insulating sheets 23a, 23b, and 23c, and the second power terminals 25a, 25b, and 25c on the first side portion 21a are exposed. The end face of the thermally anisotropic sheet 24 on the first side portion 21a may be exposed.

[0026] As shown in FIG. 5, the boundary portions of the first power terminals 22a, 22b, and 22c (the first power terminal 22 in FIG. 6) directly below the leading ends of the first insulating sheets 23a, 23b, and 23c are spaced a predetermined distance from the leading ends of the second power terminals 25a, 25b, and 25c (the second power terminal 25 in FIG. 6). That is, the distances of the leading ends of the first insulating sheets 23a, 23b, and 23c extending from the leading ends of the second power terminals 25a, 25b, and 25c toward the exposed surfaces of the first power terminals 22a, 22b, and 22c are adjusted. This maintains a creepage distance between the first power terminals 22a, 22b, and 22c and the second power terminals 25a, 25b, and 25c. Note that the distance varies depending on the withstand voltage of the semiconductor device 10. This distance is, for example, 3 mm or more and 14.5 mm or less. Alternatively, it may be 6 mm or more and 12.5 mm or less. Furthermore, if the withstand voltage value is 750 V, this distance may be 7.5 mm plus a tolerance of 0.5 mm, and if it is 1200 V, this distance may be 12 mm plus a tolerance of 0.5 mm.

[0027] One end of each of control terminals 27a, 27b, and 27c extends upward (in the +Z direction) of semiconductor module 20. The other end of each of control terminals 27a, 27b, and 27c is electrically connected to the gate electrode (control electrode) of the semiconductor chip of each semiconductor unit in storage areas 21e1, 21e2, and 21e3, respectively. Control terminals 27a, 27b, and 27c are made of a metal with excellent conductivity. Examples of such metals include copper, copper alloys, aluminum, and aluminum alloys.

[0028] The other ends of U terminal 28a, V terminal 28b, and W terminal 28c are electrically connected to the source electrodes (or emitter electrodes) of the semiconductor chips of the semiconductor units in storage areas 21e1, 21e2, and 21e3, respectively. One ends of U terminal 28a, V terminal 28b, and W terminal 28c are exposed on third side 21c of case 21 along the longitudinal direction of case 21 (third side 21c). U terminal 28a, V terminal 28b, and W terminal 28c are made of a metal with excellent conductivity. Such a metal is, for example, copper or a copper alloy.

[0029] Such a semiconductor module 20 includes the equivalent circuit shown in FIG. 4. In FIG. 4, it is sufficient that switching elements are used, and power MOSFETs or IGBTs may be used as the semiconductor chips. In semiconductor module 20, second power terminals 25a, 25b, and 25c, which are P-terminals, are electrically connected to collector electrodes of the semiconductor chips of the respective semiconductor units within storage areas 21e1, 21e2, and 21e3. U-terminal 28a, V-terminal 28b, and W-terminal 28c are electrically connected to emitter electrodes of the semiconductor chips of the respective semiconductor units within storage areas 21e1, 21e2, and 21e3. First power terminals 22a, 22b, and 22c, which are N-terminals, are electrically connected to emitter electrodes of the semiconductor chips of the respective semiconductor units within storage areas 21e1, 21e2, and 21e3.

[0030] Next, capacitor 30 will be described with reference to FIG. 5. FIG. 5 shows a capacitor according to a first embodiment. FIG. 5(A) is a perspective view of capacitor 30, and FIG. 5(B) is a perspective view of capacitor 30 from the opposite direction to that of FIG. 5(A). Capacitor 30 includes a case 31, a first connection terminal 32, a second insulating sheet 33, and a second connection terminal 34.

[0031] The case 31 is the capacitor body. The case 31 is composed of a lid portion 31a and a storage case 31b. A first connection terminal 32, a second insulating sheet 33, and a second connection terminal 34 are arranged on the lid portion 31a. A plurality of capacitors having an N pole and a P pole are stored in the storage case 31b. The lid portion 31a and the storage case 31b are made of a material such as epoxy resin. The other ends of the first connection terminals 32 are all electrically connected to the N poles of the capacitor elements inside the case 31. One end of the first connection terminal 32 extends outward toward a fifth side portion 31c of the case 31. The portion of the first connection terminal 32 extending from the case 31 is generally L-shaped in side view. The generally L-shaped first connection terminal 32 includes a first conductive portion 321 and a first wiring portion 322, as will be described later with reference to FIG. 6. The other end of the first conductive portion 321 is electrically connected to the N pole of the capacitor element inside the case 31, and extends vertically to the outside from the front surface of the lid portion 31a of the case 31. The first wiring portion 322 extends substantially perpendicular to the first conductive portion 321 and substantially parallel to the front surface of the lid portion 31a of the case 31 toward the fifth side portion 31c. In addition, the portion of the first connection terminal 32 extending from the lid portion 31a of the case 31 (first wiring portion 322) is divided into a first connection portion 32a, a second connection portion 32b, and a third connection portion 32c, forming a comb-like shape in a plan view. Note that the reference numerals for the first connection portion 32a, the second connection portion 32b, and the third connection portion 32c are omitted in FIG. 5B. The widths of the first connection portion 32a, the second connection portion 32b, and the third connection portion 32c correspond to the widths of the storage areas 21e1, 21e2, and 21e3 (first power terminals 22a, 22b, and 22c) of the semiconductor module 20. The first connection terminal 32 is made of a metal with excellent conductivity. Such a metal is, for example, copper or a copper alloy.

[0032] The other end of the second connection terminal 34 is electrically connected to the P pole of the capacitor element inside the case 31. One end of the second connection terminal 34 extends from the fifth side 31c of the case 31 to the outside. The second connection terminal 34 is provided on the opposite side of the fifth side 31c from the first connection terminal 32, and is spaced apart from the fifth side 31c. The portion of the second connection terminal 34 extending from the case 31 is generally L-shaped in side view. As will be described later with reference to FIG. 6 , the generally L-shaped second connection terminal 34 includes a second conductive portion 341 and a second wiring portion 342. The other end of the second conductive portion 341 is electrically connected to the P pole of the capacitor element inside the case 31 and extends vertically from the front surface of the case 31 to the outside. The second wiring portion 342 extends generally perpendicular to the second conductive portion 341 and generally parallel to the front surface of the case 31 to the opposite side of the fifth side 31c. The second connection terminal 34 is made of a metal with excellent conductivity, such as copper or a copper alloy.

[0033] The second insulating sheet 33 is longer than the first connection terminal 32 and extends from between the first connection terminal 32 and the second connection terminal 34 of the case 31 to the outside. Therefore, the second insulating sheet 33 maintains insulation between the first connection terminal 32 and the second connection terminal 34 outside the case 31. The second insulating sheet 33 is made of a flexible insulating material. Examples of such insulating materials include insulating paper made of a wholly aromatic polyamide polymer, and sheet-like materials made of a fluorine-based or polyimide-based resin material.

[0034] Furthermore, the tip of second insulating sheet 33 is divided into first mounting portion 33a, second mounting portion 33b, and third mounting portion 33c in a comb-like shape in plan view. Note that the reference numerals for first mounting portion 33a, second mounting portion 33b, and third mounting portion 33c are omitted in Fig. 5(B). The widths of first mounting portion 33a, second mounting portion 33b, and third mounting portion 33c correspond to the widths of storage areas 21e1, 21e2, and 21e3 (first insulating sheets 23a, 23b, and 23c) of semiconductor module 20, respectively.

[0035] Although not shown, the case 31 is further provided with a terminal. The other end of this terminal is electrically connected to the positive and negative electrodes of all the capacitor elements inside the case 31, respectively. One end of the terminal extends from the case 31 to the outside. The extending location of the terminal on the case 31 may be different from the first connection terminal 32 and the second connection terminal 34. For example, the terminal is provided along the side opposite to the fifth side 31c. The terminal is made of a metal with excellent conductivity. Such a metal is, for example, copper or a copper alloy.

[0036] Next, the coupling members 40a, 40b, and 40c will be described (see FIG. 1). The coupling members 40a, 40b, and 40c are flat in plan view. The width of one end of the coupling members 40a, 40b, and 40c corresponds to the width of the storage areas 21e1, 21e2, and 21e3 (second power terminals 25a, 25b, and 25c) of the semiconductor module 20. The thickness of the coupling members 40a, 40b, and 40c is configured to be thinner than the thickness of the second power terminals 25a, 25b, and 25c. One end of the coupling members 40a, 40b, and 40c is joined to the second power terminals 25a, 25b, and 25c by laser welding. The other end of the coupling members 40a, 40b, and 40c is joined to the second connection terminal 34 of the capacitor 30 by laser welding. The laser welding may be performed using either a seam laser, which continuously emits laser light, or a spot laser, which emits pulsed laser light. FIG. 1 illustrates the case where the welding is performed using a seam laser. For this reason, linear laser weld marks 44a and 44b are displayed on the capacitor 30 side and the semiconductor module 20 side of the connecting members 40a, 40b, and 40c in FIG. 1 . The connecting members 40a, 40b, and 40c are made of a metal with excellent conductivity. Such a metal is, for example, copper or a copper alloy. In the first embodiment, three connecting members 40a, 40b, and 40c are respectively joined to the second power terminals 25a, 25b, and 25c. However, the present invention is not limited to this. The ends of the flat connecting members on the semiconductor module 20 side, like the first connection terminal 32 and the second insulating sheet 33, may be split into comb-like shapes to correspond to the second power terminals 25a, 25b, and 25c.

[0037] Next, the connection mechanism between the semiconductor module 20 and the capacitor 30 of the semiconductor device 10 will be described with reference to FIG. 6. FIG. 6 is a cross-sectional view showing the connection mechanism included in the semiconductor device of the first embodiment. Note that FIG. 6 is a cross-sectional view taken along the dashed dotted line XX shown in FIG. 1. Note that FIG. 6 also shows cross sections of other coupling members 40b and 40c of the semiconductor device 10 of FIG. 1, each having a similar configuration.

[0038] In the semiconductor device 10, the first wiring portion 322 of the first connection terminal 32 of the capacitor 30 is joined to the first junction region 221 of the first power terminal 22 of the semiconductor module 20. That is, although not shown, the first connection portion 32a, the second connection portion 32b, and the third connection portion 32c of the first wiring portion 322 of the first connection terminal 32 are joined to the first junction regions of the first power terminals 22a, 22b, and 22c of the semiconductor module 20. Note that the first junction region 221 is a general term for the first junction regions of the first power terminals 22a, 22b, and 22c.

[0039] The second insulating sheet 33 of the capacitor 30 covers the first connection terminal 32 from above and is bent toward the semiconductor module 20. The tip of the second insulating sheet 33 extends onto the terrace portion 29 of the first insulating sheet 23 of the semiconductor module 20. The tip of the second insulating sheet 33 also extends to just before the second power terminal 25. That is, a gap exists between the terrace portion 29 and the tip of the second insulating sheet 33 or between the tip of the second insulating sheet 33 and the connecting member 40. The distance from the tip surface of the first connection terminal 32 to the tip surface of the second power terminal 25 is 6 mm or more and 12.5 mm or less. The terrace portion 29 extends in a plan view from a second bonding region 251 (described later) toward a first bonding region 221 (described later). Although not shown, the first mounting portion 33a, the second mounting portion 33b, and the third mounting portion 33c at the tip of the second insulating sheet 33 extend onto the first insulating sheets 23a, 23b, and 23c of the semiconductor module 20, respectively.

[0040] The front surface of the second wiring portion 342 of the second connection terminal 34 of the capacitor 30 is flush with the front surface of the second power terminal 25 of the semiconductor module 20. One end of the linking member 40 is joined to the third bonding region 343 of the second wiring portion 342 of the second connection terminal 34 of the capacitor 30, and the other end of the linking member 40 is joined to the second bonding region 251 of the second power terminal 25 of the semiconductor module 20. In this case, the second bonding region 251 and the third bonding region 343 are arranged parallel to the first bonding region 221. Although not shown, the other ends of the linking members 40a, 40b, and 40c are joined to the second bonding regions of the second power terminals 25a, 25b, and 25c of the semiconductor module 20. The second bonding region 251 is a collective term for the second bonding regions of the second power terminals 25a, 25b, and 25c. As a result, the coupling member 40 electrically connects the second connection terminal 34 of the capacitor 30 and the second power terminal 25 of the semiconductor module 20. A gap is formed between the back surface of the coupling member 40 and the front surface of the first wiring portion 322 of the first connection terminal 32 of the capacitor 30. The second insulating sheet 33 is provided in this gap. As a result, the first connection terminal 32 maintains insulation from the coupling member 40 and the second connection terminal 34. Furthermore, the second insulating sheet 33 is not limited to the state shown in FIG. 5 , and may be in contact with the back surface of the coupling member 40, the front surface of the first connection terminal 32, and the tip portion of the second power terminal 25 within this gap.

[0041] Next, a method for connecting the semiconductor module 20 and the capacitor 30 in such a semiconductor device 10 will be described with reference to Figures 7, 8, and 6. Figures 7 and 8 are cross-sectional views for explaining the connection method of the semiconductor device of the first embodiment.

[0042] First, the tip of the first wiring portion 322 of the first connection terminal 32 of the capacitor 30 is aligned with the first power terminal 22 of the semiconductor module 20. At this time, the front surface of the second wiring portion 342 of the second connection terminal 34 of the capacitor 30 and the front surface of the second power terminal 25 (second power terminals 25a, 25b, 25c) of the semiconductor module 20 are flush with each other. In this state, the tip of the first wiring portion 322 is joined to the first joint region 221 of the first power terminal 22 by laser welding ( FIG. 7 ). The first power terminal 22 protrudes from the first side portion 21a. There is nothing around the first joint region 221 of the first power terminal 22 that is affected by heat. Therefore, the heat from laser welding has almost no effect on anything else.

[0043] As described above, the first wiring portion 322 has a comb-like shape in plan view, divided into the first connection portion 32a, the second connection portion 32b, and the third connection portion 32c. Therefore, the first connection portion 32a, the second connection portion 32b, and the third connection portion 32c of the first wiring portion 322 are joined to the first joining regions of the first power terminals 22a, 22b, and 22c of the terminal regions 21a1, 21a2, and 21a3, respectively. The first power terminals 22a, 22b, and 22c are located behind the first connection portion 32a, the second connection portion 32b, and the third connection portion 32c.

[0044] Next, the second insulating sheet 33 of the capacitor 30 is folded toward the semiconductor module 20. Because the second insulating sheet 33 is flexible, it can be folded all at once. After folding, the tip of the second insulating sheet 33 is positioned on the terrace portion 29 of the first insulating sheet 23 that is exposed between the first power terminal 22 and the second power terminal 25 of the semiconductor module 20 ( FIG. 8 ). Note that the folded second insulating sheet 33 may be in contact with the first power terminal 22, the first insulating sheet 23, and the second power terminal 25. As described above, the tip of the second insulating sheet 33 is divided into a first mounting portion 33a, a second mounting portion 33b, and a third mounting portion 33c to form a comb-like shape in a plan view. Therefore, the first mounting portion 33a, the second mounting portion 33b, and the third mounting portion 33c of the second insulating sheet 33 cover the first insulating sheets 23a, 23b, and 23c, respectively. The first insulating sheets 23a, 23b, and 23c are located on the backsides of the first mounting portion 33a, the second mounting portion 33b, and the third mounting portion 33c of the second insulating sheet 33.

[0045] Next, one end and the other end of the coupling member 40 are set on the front surface of the second wiring portion 342 of the second connection terminal 34 of the capacitor 30 and the front surface of the second power terminal 25 of the semiconductor module 20, respectively. Then, by laser welding, the one end and the other end of the coupling member 40 are joined to the front surface of the second wiring portion 342 of the capacitor 30 and the front surface of the second power terminal 25 of the semiconductor module 20, respectively (FIG. 6). At this time, there is nothing around the second wiring portion 342 of the second connection terminal 34 that is affected by the heat. Therefore, the heat from the laser welding has almost no effect on anything else.

[0046] Because the thickness of the connecting member 40 is thinner than the thickness of the second power terminal 25, laser welding can be performed more effectively. However, heat propagates from the laser-welded second joint region 251 toward the case 21 (in the -Z direction). In the semiconductor module 20, a thermally anisotropic sheet 24 is provided between the second power terminal 25 and the first insulating sheet 23. The thermally anisotropic sheet 24 propagates the heat from the second joint region 251 along the XY plane, suppressing propagation to the first insulating sheet 23. This makes it possible to suppress damage to the first insulating sheet 23 due to the heat of laser welding. Therefore, insulation between the first power terminal 22 and the second power terminal 25 can be maintained.

[0047] Furthermore, such coupling members 40a, 40b, 40c respectively join the second power terminals 25a, 25b, 25c of the semiconductor module 20 to the second wiring portion 342 of the second connection terminal 34 of the capacitor 30. In this manner, the semiconductor device 10 in which the semiconductor module 20 and the capacitor 30 are coupled to each other is obtained (FIG. 1).

[0048] Next, a description will be given of conditions for preventing the heat of laser welding when connecting semiconductor module 20 to capacitor 30 from affecting first insulating sheets 23a, 23b, 23c. The thickness of thermally anisotropic sheet 24 and the thermal conductivity in the direction along the XY plane are set to predetermined values ​​so that the maximum temperature of the surface of thermally anisotropic sheet 24 facing first insulating sheets 23a, 23b, 23c when second power terminals 25a, 25b, 25c are heated is equal to or lower than the heat resistance temperature of first insulating sheets 23a, 23b, 23c.

[0049] The temperature versus change in thermal conductivity depending on the thickness of the thermally anisotropic sheet 24 will be described with reference to Figures 9 to 11. Figure 9 is a graph showing the thermal conductivity and instantaneous maximum temperature of the insulating sheet depending on the thickness of the thermally anisotropic sheet included in the semiconductor module of the first embodiment, and Figure 10 is a graph showing the thermal conductivity and instantaneous maximum temperature of the thermally anisotropic sheet depending on the thickness of the thermally anisotropic sheet included in the semiconductor module of the first embodiment. Figure 11 is a diagram showing an analysis of heat due to laser welding of the semiconductor device of the first embodiment.

[0050] The graph in Fig. 9 shows the results when no thermally anisotropic sheet 24 is provided (0 μm) and when the thickness of the thermally anisotropic sheet 24 is 25 μm, 50 μm, 100 μm, 150 μm, 200 μm, and 300 μm. The X-axis in Fig. 9 represents the thermal conductivity (W / mK) in the direction along the XY plane, and the Y-axis represents the instantaneous maximum temperature (°C) of first insulating sheet 23 for that thermal conductivity.

[0051] 10 shows the results when the thickness of the thermally anisotropic sheet 24 is 25 μm, 50 μm, 100 μm, 150 μm, 200 μm, and 300 μm. The X-axis of FIG. 10 represents the thermal conductivity (W / mK) in the direction along the XY plane, and the Y-axis represents the instantaneous maximum temperature (°C) of the thermally anisotropic sheet 24 for that thermal conductivity.

[0052] Here, as shown in FIG. 6, the first power terminal 22, first insulating sheet 23, thermally anisotropic sheet 24, second power terminal 25, and connecting member 40 were stacked in this order, and the instantaneous maximum temperatures of the first insulating sheet 23 and the thermally anisotropic sheet 24 were analyzed when laser welding was performed by irradiating a laser perpendicularly to the front surface of the connecting member 40 of the top layer. FIG. 11 schematically shows the results of heat analysis for this structure under specified conditions. In FIG. 11, point P is the laser welding location. In this analysis, the heat input by laser welding is approximately 86 J. The first and second power terminals 22 and 25 are each made of copper and each have a thickness of approximately 1.5 mm. The specific heat of the first and second power terminals 22 and 25 is 0.39 J / gK and the thermal conductivity is 401 W / mK.

[0053] The thickness of the first insulating sheet 23 is approximately 0.38 mm. The specific heat of the first insulating sheet 23 is 1.21 J / gK and the thermal conductivity is 0.15 W / mk. The thickness of the connecting member 40 is approximately 0.8 mm. The connecting member 40 is made of copper, just like the first and second power terminals 22, 25. Therefore, the specific heat and thermal conductivity of the connecting member 40 are similar to those of the first and second power terminals 22, 25.

[0054] In this case, the temperature (instantaneous maximum temperature) at which the first insulating sheet 23 reaches its maximum was analyzed according to the thickness of the thermally anisotropic sheet 24. Note that Fig. 9 shows the instantaneous maximum temperature and thermal conductivity at the welded portion at the boundary between the member corresponding to the second power terminal 25 and the member corresponding to the connecting member 40 when the thermally anisotropic sheet 24 is not provided.

[0055] In this case, the thermally anisotropic sheet 24 is made of graphite and has a thickness of 0.34 mm. The specific heat of the thermally anisotropic sheet 24 is 0.85 J / gK, and the thermal conductivity (±Z direction) is 5 W / mk. The heat resistance temperature of the thermally anisotropic sheet 24 in the atmosphere is approximately 450°C. Therefore, the thermally anisotropic sheet 24 will be damaged if this heat resistance temperature is exceeded. Therefore, the energy applied to the second power terminal 25 and the thickness of the second power terminal 25 are adjusted to predetermined values ​​so that the maximum temperature of the surface of the second power terminal 25 facing the thermally anisotropic sheet 24 when the second power terminal 25 is heated will be below the heat resistance temperature of the thermally anisotropic sheet 24.

[0056] 9, it can be seen that the thicker the thermally anisotropic sheet 24 is and the higher its thermal conductivity in the direction along the XY plane, the more the instantaneous maximum temperature of the first insulating sheet 23 is reduced. The heat resistance temperature of the first insulating sheet 23 depends on the material of the first insulating sheet 23. It is also desirable to appropriately select the thermal conductivity and thickness of the thermally anisotropic sheet 24, along with the material of the first insulating sheet 23. It can also be seen from the graph in FIG. 10 that the thicker the thermally anisotropic sheet 24 is and the higher its thermal conductivity in the direction along the XY plane, the more the instantaneous maximum temperature of the thermally anisotropic sheet 24 is reduced.

[0057] The heat resistance temperature of first insulating sheet 23 may be, for example, 300°C or 260°C. When first insulating sheet 23 has a heat resistance temperature of 300°C, according to the graph of Fig. 9, thermally anisotropic sheet 24 preferably has a thermal conductivity of 1500 W / mK or more in the direction along the XY plane and a thickness of 50 µm or more, and more preferably has a thermal conductivity of 350 W / mK or more in the direction along the XY plane and a thickness of 100 µm or more. Furthermore, thermally anisotropic sheet 24 more preferably has a thermal conductivity of 100 W / mK or more in the direction along the XY plane and a thickness of 150 µm or more.

[0058] When the heat resistance temperature of the first insulating sheet 23 is 260°C, according to the graph in Figure 9, it is preferable that the thermal anisotropic sheet 24 has a thermal conductivity of 300 W / mK or more in the direction along the XY plane and a thickness of 150 μm or more, and it is more preferable that the thermal conductivity of 100 W / mK or more in the direction along the XY plane and a thickness of 200 μm or more.

[0059] FIG. 11 shows the analysis results when the heat resistance temperature of the first insulating sheet 23 is 260°C, the thermal conductivity of the thermally anisotropic sheet 24 in the direction along the XY plane is 1000 W / mK, and the thickness is 300 μm. FIG. 11 shows that temperature is conducted from point P in the +X, -Y, and -Z directions. In this case, hatching with the same pattern represents the same temperature. Areas without hatching are not affected by the heat from laser welding, meaning that there is almost no temperature change before and after laser welding.

[0060] 11, it can be seen that the temperature is conducted in the +X direction and the -Y direction from the point P in the connecting member 40 and the second power terminal 25. In this case, the temperature decreases with increasing distance from the point P.

[0061] Furthermore, temperature is also conducted in the -Z direction through the connecting member 40 and the second power terminal 25. However, the temperature directly below point P of the thermally anisotropic sheet 24 is lower than the temperature at point P of the connecting member 40 and the second power terminal 25. Furthermore, temperature is conducted in the thermally anisotropic sheet 24 from the position directly below point P in the +X direction and the -Y direction while decreasing.

[0062] Furthermore, it can be seen that the first insulating sheet 23, located below the thermally anisotropic sheet 24 (in the -Y direction), shows only a slight increase in temperature on the thermally anisotropic sheet 24 side, but no temperature change occurs overall. This is because the thermally anisotropic sheet 24 effectively conducts the heat generated by laser welding along the XY plane and slows down heat conduction in the -Z direction. Therefore, the thermally anisotropic sheet 24 widens the temperature rise range of the second power terminal 25 and the thermally anisotropic sheet 24, suppressing localized temperature increases. Furthermore, the second power terminal 25 has a higher thermal conductivity and is thicker than the first insulating sheet 23. This reduces the amount of heat conducted to the first insulating sheet 23, thereby reducing the instantaneous maximum temperature of the first insulating sheet 23. From the above, it can be considered that thermal damage to the first insulating sheet 23 is suppressed.

[0063] The case 21 of the semiconductor module 20 is integrally formed by stacking the first power terminals 22a, 22b, and 22c, the first insulating sheets 23a, 23b, and 23c, the thermally anisotropic sheet 24, and the second power terminals 25a, 25b, and 25c. An adhesive may be applied between the first insulating sheets 23a, 23b, and 23c and the thermally anisotropic sheet 24. To prevent misalignment, the thermally anisotropic sheet 24 may have portions extending beyond the range indicated by the dotted lines in FIG. 6 in the ±Y directions and portions overlapping the second power terminals 25a, 25b, and 25c in a plan view. This increases the area of ​​the thermally anisotropic sheet 24 that is sandwiched between the case 21, preventing misalignment from the terminal stacking portions 26a, 26b, and 26c.

[0064] Alternatively, a graphene film may be formed by printing on the side of the second power terminals 25a, 25b, 25c facing the first insulating sheets 23a, 23b, 23c, as described in, for example, JP-A No. 2019-52931. In this case, the thermally anisotropic sheet 24 is formed directly on the second power terminals 25a, 25b, 25c and is merely in contact with the first insulating sheets 23a, 23b, 23c.

[0065] The semiconductor module 20 includes terminal stacks 26a, 26b, and 26c, in which first power terminals 22a, 22b, and 22c, first insulating sheets 23a, 23b, and 23c, and second power terminals 25a, 25b, and 25c are stacked in this order. A thermally anisotropic sheet 24, which has a higher thermal conductivity in a planar direction perpendicular to the stacking direction of the terminal stacks 26a, 26b, and 26c than in the stacking direction of the terminal stacks 26a, 26b, and 26c, is provided between the first insulating sheets 23a, 23b, and 23c and the second power terminals 25a, 25b, and 25c. This prevents heat from being transmitted by the laser to the first insulating sheets 23a, 23b, and 23c when the connecting member 40 is laser-welded to the front surfaces of the second power terminals 25a, 25b, and 25c. This can prevent damage to first insulating sheets 23a, 23b, and 23c, and maintain insulation between first power terminals 22a, 22b, and 22c and second power terminals 25a, 25b, and 25c, thereby preventing electrical defects in semiconductor module 20 and preventing a decrease in reliability of semiconductor module 20 and semiconductor device 10 including semiconductor module 20.

[0066] [Second embodiment] In the second embodiment, a semiconductor device 10a having a different configuration from the semiconductor device 10 of the first embodiment will be described with reference to FIG. 12. FIG. 12 is a cross-sectional view of a connection portion of a semiconductor module of the second embodiment. Note that FIG. 12 corresponds to the cross-sectional view of the semiconductor device 10 of the first embodiment in FIG. 6. Note that in the second embodiment, the same components as those of the semiconductor device 10 of the first embodiment are denoted by the same reference numerals, and their description will be simplified or omitted.

[0067] The semiconductor device 10a includes a semiconductor module 20a and a capacitor 30a. In the semiconductor module 20a, an end of the first power terminal 22 extends to be flush with the first side portion 21a of the case 21. Other configurations of the semiconductor module 20a are similar to those of the semiconductor module 20.

[0068] The capacitor 30a includes a first connection terminal 32, a second insulating sheet 133, and a second connection terminal 34b. In this case, the second connection terminal 34b has a second conductive portion 341 and a second wiring portion 342b. However, the second wiring portion 342b of the capacitor 30a extends toward the fifth side portion 31c, parallel to the first wiring portion 322 of the first connection terminal 32, up to just before the fifth side portion 31c. Furthermore, the front surface of the second wiring portion 342b of the second connection terminal 34b and the front surface of the second power terminal 25 of the semiconductor module 20a are flush with each other. One end of the coupling member 40 is joined to a second bonding region 251 on the front surface of the second power terminal 25, and the other end of the coupling member 40 is joined to a third bonding region 343 on the front surface of the second wiring portion 342b. In this manner, the semiconductor module 20a and the capacitor 30a are electrically connected.

[0069] The second insulating sheet 133 extends from between the first connection terminal 32 and the second connection terminal 34b of the case 31. In the case of FIG. 12, the second insulating sheet 133 extends along the front surface of the first connection terminal 32. The tip of the second insulating sheet 133 is located between the tip of the first connection terminal 32 and the tip of the second connection terminal 34b. This maintains insulation between the first connection terminal 32 and the second connection terminal 34b. A gap is formed between the front surface of the first wiring portion 322 of the first connection terminal 32 and the back surface of the coupling member 40. The third insulating sheet 41 is provided in this gap. That is, the third insulating sheet 41 is provided between the tip of the second insulating sheet 133, which is located between the tip of the first connection terminal 32 and the tip of the second connection terminal 34b, and the tip of the first insulating sheet 23. The third insulating sheet 41 is also made of the same material as the second insulating sheet 133. One end of the third insulating sheet 41 is bonded to the terrace portion 29 of the first insulating sheet 23, and the other end of the third insulating sheet 41 is bonded to the tip of the second insulating sheet 133. A known adhesive is used for this bonding. The end of the third insulating sheet 41 facing the semiconductor module 20a is divided into a comb-like shape corresponding to the storage areas 21e1, 21e2, and 21e3 of the semiconductor module 20a in a plan view. The end of the third insulating sheet 41 facing the capacitor 30a is configured to have the same width as or wider than the second insulating sheet 133 in a plan view. The second insulating sheet 133 and the third insulating sheet 41 ensure that the first connecting terminal 32 is insulated from the second connecting terminal 34b, the coupling member 40, and the second power terminal 25. 12, the second insulating sheet 133 may cover the first connection terminal 32 and extend to the first insulating sheet 23. In this case, the end of the second insulating sheet 133 on the semiconductor module 20a side is comb-shaped, similar to the second insulating sheet 33 in FIG. 5. In this case, the third insulating sheet 41 is not necessary.

[0070] Furthermore, the capacitor 30a has a thermally anisotropic sheet 124 provided between the back surface of the second connection terminal 34b (second wiring portion 342b) and the second insulating sheet 133. The thermally anisotropic sheet 124 is made of the same material as the thermally anisotropic sheet 24. The end of the thermally anisotropic sheet 124 on the fifth side 31c side is flush with the end of the second wiring portion 342b. In FIG. 12, the end of the thermally anisotropic sheet 124 on the opposite side from the fifth side 31c extends onto the straight portion of the second wiring portion 342b. However, the end of the thermally anisotropic sheet 124 on the opposite side from the fifth side 31c may extend to the front surface of the case 31. The coupling member 40 is laser welded to the second connection terminal 34b (second wiring portion 342b) using this thermally anisotropic sheet 124. Heat propagates from the laser-welded coupling member 40 toward the case 31 (-Z direction). Heat from the second wiring portion 342b propagates along the XY plane by the thermally anisotropic sheet 124, and is prevented from propagating to the second insulating sheet 133. This makes it possible to prevent damage to the second insulating sheet 133 due to the heat of laser welding. This makes it possible to maintain insulation between the second connection terminal 34b and the first connection terminal 32. [Explanation of symbols]

[0071] 10, 10a Semiconductor device 20,20a semiconductor module 21,31 cases 21a, 21b, 21c, 21d First, second, third, fourth side 21a1,21a2,21a3 terminal area 21e, 21e1, 21e2, 21e3 storage area 22, 22a, 22b, 22c First power terminal (first terminal) 23, 23a, 23b, 23c First insulating sheet (insulating member) 24 Thermally anisotropic sheet (thermally anisotropic member) 25, 25a, 25b, 25c Second power terminal (second terminal) 26, 26a, 26b, 26c Terminal stacking section 27a, 27b, 27c control terminals 28a U terminal 28b V terminal 28c W terminal 29, 29a, 29b, 29c Terrace area 30,30a capacitor 31a Lid 31b Storage case 31c 5th side 32 First connection terminal 32a First connection part 32b Second connection part 32c Third connection part 33,133 Second insulation sheet 33a First mounting part 33b Second mounting part 33c Third mounting part 34, 34b Second connection terminal 40, 40a, 40b, 40c connecting members 41 Insulation sheet 44a, 44b Laser welding marks 124 Thermally Anisotropic Sheet 221 1st junction area 251 2nd junction area 321 First Conductive Section 322 1st wiring section 341 Second Conductive Section 342,342b 2nd wiring section 343 Third junction area

Claims

1. a terminal stack portion in which a first terminal, an insulating member, and a second terminal are stacked in this order; a thermally anisotropic member having a higher thermal conductivity in a planar direction perpendicular to the stacking direction of the terminal stack portion than in a stacking direction of the terminal stack portion is provided between the insulating member and the second terminal; Semiconductor module.

2. the thickness and the thermal conductivity in the planar direction of the thermal anisotropic member are set to predetermined values ​​so that the maximum temperature of the surface of the thermal anisotropic member facing the insulating member when the second terminal is heated is equal to or lower than the heat resistance temperature of the insulating member; The semiconductor module according to claim 1 .

3. When the heat resistance temperature of the insulating member is 300°C, The thickness of the thermally anisotropic member is 50 μm or more and 200 μm or less. The semiconductor module according to claim 2 .

4. The thermal conductivity of the thermally anisotropic member in the planar direction is 1500 W / mK or more. The semiconductor module according to claim 3 .

5. The thickness of the thermally anisotropic member is 100 μm or more and 150 μm or less. The semiconductor module according to claim 3 .

6. The thermal conductivity of the thermally anisotropic member in the planar direction is 1000 W / mK or more. The semiconductor module according to claim 5 .

7. When the heat resistance temperature of the insulating member is 260°C, The thickness of the thermally anisotropic member is 150 μm or more. The semiconductor module according to claim 2 .

8. The thermal conductivity of the thermally anisotropic member in the planar direction is 300 W / mK or more. The semiconductor module according to claim 7 .

9. The thickness of the thermally anisotropic member is 200 μm or more. The semiconductor module according to claim 7 .

10. The thermal conductivity of the thermally anisotropic member in the planar direction is 100 W / mK or more. The semiconductor module according to claim 9 .

11. The thermally anisotropic member is mainly composed of graphite. The semiconductor module according to claim 2 .

12. the first terminal includes a first bonding region on a front surface extending in one direction from the second terminal in a plan view; the insulating member includes a terrace portion extending from the second terminal toward the first bonding region in a plan view, The second terminal further includes a connecting member joined to a second joining region on the front surface of the second terminal. The semiconductor module according to claim 1 .

13. The thermal anisotropic member is provided directly below the connecting member in a plan view. The semiconductor module according to claim 12.

14. the thermal anisotropic member is provided so as to extend up to an outer edge of the second terminal in a plan view; The semiconductor module according to claim 13 .

15. The thermally anisotropic member is in the form of a sheet. The semiconductor module according to claim 1 .

16. the thermally anisotropic member is formed on a rear surface of the second terminal and is provided between the second terminal and the insulating member; The semiconductor module according to claim 1 .

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