Semiconductor module

Abstract

To increase current rating of a semiconductor module while aiming to reduce a size thereof.SOLUTION: A semiconductor module includes a base plate, an insulating substrate disposed on one surface of the base plate, a frame-shaped case surrounding the insulating substrate, and a plurality of external terminals disposed both inside and outside the case. The insulating substrate includes an insulating board, and a conductor pattern disposed on one surface of the insulating board. At least one of the external terminals includes a pin extending toward an outside of the case along a thickness direction of the insulating substrate, a leg extending toward an inside of the case along a direction intersecting an extension direction of the pin, and a connection extending from the pin toward the insulating substrate along the thickness direction of the insulating substrate. The connection is in contact with the conductor pattern while receiving compression force produced between the insulating substrate and the case.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] A semiconductor module, typified by a power semiconductor module, includes an insulating substrate on which a semiconductor chip is mounted, a case for accommodating the insulating substrate, and a plurality of external terminals electrically connected to the semiconductor chip, as disclosed in, for example, Patent Documents 1 to 4.

[0003] In Patent Document 1, main terminals (external terminals) fixed to a housing (case) are electrically connected to a semiconductor chip or an insulating substrate within the housing via bonding wires. Furthermore, in Patent Document 1, the insulating substrate is disposed on a base plate with excellent thermal conductivity, such as copper or aluminum, and a high-heat-dissipation insulator is disposed between the base plate and the main terminals to reduce the thermal resistance in the region between the main terminals and the base plate. This high-heat-dissipation insulator is fixed to the housing together with the main terminals by insert molding. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-005129 [Patent Document 2] Japanese Patent Application Publication No. 2017-92388 [Patent Document 3] Japanese Patent Application Laid-Open No. 2000-208686 [Patent Document 4] International Publication No. 2021 / 085216 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the module described in Patent Document 1, the number of bonding wires connecting the main terminals and the insulating substrate is large, making it difficult to mount a large semiconductor chip with a high current rating on the insulating substrate while also miniaturizing the case.

[0006] In consideration of the above circumstances, one aspect of the present disclosure aims to increase the current rating of a semiconductor module while achieving miniaturization. [Means for solving the problem]

[0007] In order to solve the above problems, a semiconductor module according to a preferred embodiment of the present disclosure comprises a base plate, an insulating substrate disposed on one surface of the base plate and on which a semiconductor chip is provided, a frame-shaped case surrounding the insulating substrate, and a plurality of external terminals disposed inside and outside the case and electrically connected to the semiconductor chip, wherein the insulating substrate has an insulating plate and a conductor pattern disposed on one surface of the insulating plate and including conductors joined to the semiconductor chip, and at least one external terminal of the plurality of external terminals has a pin portion extending toward the outside of the case along a thickness direction of the insulating substrate, a leg portion extending toward the inside of the case along a direction intersecting the extension direction of the pin portion, and a connection portion extending from the pin portion toward the insulating substrate along the thickness direction of the insulating substrate, and the connection portion contacts the conductor pattern when subjected to a compressive force between the insulating substrate and the case. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an exploded perspective view of a semiconductor module according to an embodiment; [Figure 2] 1 is a cross-sectional view of a semiconductor module according to an embodiment. [Figure 3] 1 is a cross-sectional view of a semiconductor module according to an embodiment. [Figure 4] 1 is a cross-sectional view of a semiconductor module according to an embodiment. [Figure 5] FIG. 2 is a perspective view of an external terminal according to the embodiment. [Figure 6] 10A to 10C are diagrams for explaining an example of manufacturing an external terminal. [Figure 7] FIG. 10 is a cross-sectional view of a semiconductor module according to a first modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present disclosure will be described below with reference to the drawings. Note that the dimensions and scale of each part in the drawings may differ from the actual dimensions and are shown schematically to facilitate understanding. Furthermore, the scope of the present disclosure is not limited to these embodiments unless otherwise specified in the following description to the effect that the present disclosure is limited.

[0010] 1. Embodiment 1-1. Overall configuration of semiconductor module 1 is an exploded perspective view of a semiconductor module 10 according to an embodiment. The semiconductor module 10 is a power module such as an IGBT (Insulated Gate Bipolar Transistor) module. The semiconductor module 10 is used for power control in devices such as inverters or rectifiers mounted on equipment such as railway vehicles, automobiles, or household electrical appliances.

[0011] 1, a semiconductor module 10 includes a plurality of insulating substrates 20, a plurality of semiconductor chips 30, a base plate 40, a case 50, a plurality of external terminals 60, a spacer 70, and a lid 80. Note that in FIG. 1, the insulating substrates 20 and the semiconductor chips 30 are shown simply.

[0012] Hereinafter, each part of the semiconductor module 10 will be described in order based on FIG. 1. For convenience, the following description will be made using the mutually orthogonal X-axis, Y-axis, and Z-axis as appropriate. The Z-axis is an axis parallel to the thickness direction of the semiconductor module 10. Hereinafter, one direction along the X-axis is the X1 direction, and the direction opposite to the X1 direction is the X2 direction. One direction along the Y-axis is the Y1 direction, and the direction opposite to the Y1 direction is the Y2 direction. One direction along the Z-axis is the Z1 direction, and the direction opposite to the Z1 direction is the Z2 direction. The relationship between these directions and the vertical direction is not particularly limited and is arbitrary. Hereinafter, viewing in the direction along the Z-axis may be referred to as a "planar view."

[0013] Each of the multiple insulating substrates 20 is a substrate such as a DCB (Direct Copper Bonding) substrate or a DBA (Direct Bonded Aluminum) substrate. Multiple semiconductor chips 30 are mounted on one of the two surfaces of each insulating substrate 20, and a base plate 40 is bonded to the other surface. In the example shown in FIG. 1 , the thickness direction of each insulating substrate 20 is along the Z axis. Multiple semiconductor chips 30 are mounted on the surface of each insulating substrate 20 facing the Z1 direction, and a base plate 40 is bonded to the surface of each insulating substrate 20 facing the Z2 direction. In this manner, the insulating substrate 20 is disposed on one surface of the base plate 40, and the semiconductor chips 30 are provided on the insulating substrate 20. The number of semiconductor chips 30 mounted on each insulating substrate 20 is arbitrary. Furthermore, the number of insulating substrates 20 included in the semiconductor module 10 is not limited to the example shown in FIG. 1 , and may be two or less or four or more.

[0014] At least one of the multiple semiconductor chips 30 mounted on the insulating substrate 20 is a power semiconductor chip such as an IGBT. In this embodiment, the insulating substrate 20 mounts, as the semiconductor chips 30, switching elements such as IGBTs as well as control chips for controlling the operation of the power semiconductor chips. An input electrode, which is a drain electrode or a collector electrode, is provided on the back surface of the switching element. Meanwhile, an output electrode, which is a source electrode or an emitter electrode, and a control electrode, which is a gate electrode, are provided on the front surface of the switching element. Note that an element such as an FWD (Free Wheeling Diode) for commutating a load current may also be mounted on the insulating substrate 20. Furthermore, the semiconductor chip 30 serving as the control chip may be provided or omitted as needed. Furthermore, while each semiconductor chip 30 is indicated by a two-dot chain line in FIG. 1 , the arrangement of the semiconductor chips 30 on the insulating substrate 20 is not limited to the example shown in FIG. 1 and may be arbitrary.

[0015] The base plate 40 is a plate-shaped member for heat dissipation, and is made of, for example, copper, copper alloy, aluminum, or aluminum alloy. The base plate 40 has high thermal conductivity and dissipates heat from the semiconductor chip 30. The base plate 40 also has high electrical conductivity and is electrically connected to, for example, a reference potential such as a ground potential. Note that the base plate 40 is not limited to a metal plate as long as it has high thermal conductivity, and may be made of an insulator such as ceramics.

[0016] In the example shown in FIG. 1 , the thickness direction of the base plate 40 is along the Z-axis. A plurality of insulating substrates 20 are bonded to the surface of the base plate 40 facing the Z1 direction, while a heat dissipation member such as a heat dissipation fin (not shown) is bonded to the surface of the base plate 40 facing the Z2 direction. When viewed along the Z-axis, the base plate 40 has a shape with a pair of long sides extending along the X-axis and a pair of short sides extending along the Y-axis. Mounting holes 41 are provided in the base plate 40 near each short side. The mounting holes 41 are, for example, through-holes used to screw a heat dissipation member such as a heat dissipation fin (not shown) to the base plate 40. The planar shape and number of the base plate 40 are not limited to the example shown in FIG. 1 and are arbitrary. The mounting holes 41 may be provided as needed or omitted. The heat dissipation member such as a heat dissipation fin may be integral with the base plate 40.

[0017] The case 50 is a frame-shaped member that houses the insulating substrates 20 and the semiconductor chips 30. Here, the case 50 has a frame shape that surrounds the insulating substrates 20 and the semiconductor chips 30. The case 50 is essentially an insulator and is made of a resin material such as PPS (Polyphenylene Sulfide) or PBT (Polybutylene Terephthalate). Note that the resin material may contain an inorganic filler such as alumina or silica from the viewpoint of improving the mechanical strength of the case 50 or reducing the linear expansion coefficient.

[0018] The case 50 is provided with a plurality of terminal holes 51 arranged along the circumferential direction of the case 50. Each of the plurality of terminal holes 51 is a hole for inserting an external terminal 60, and passes through the case 50.

[0019] In the example shown in FIG. 1 , the thickness direction of the case 50 is along the Z-axis, and each terminal hole 51 extends along the Z-axis. Furthermore, when viewed along the Z-axis, the case 50 has an outer shape with a pair of long sides extending along the X-axis and a pair of short sides extending along the Y-axis. Furthermore, the case 50 is provided with a plurality of holes 52 and a plurality of holes 53. The plurality of holes 52 are holes used to screw a substrate (not shown) on which the semiconductor module 10 is mounted to the case 50. The plurality of holes 53, together with the above-mentioned mounting hole 41, are through-holes used to screw a heat dissipation member (not shown), such as a heat dissipation fin, to the base plate 40. The shape of the case 50 is not limited to the example shown in FIG. 1 and may be any shape. Furthermore, the holes 52 and 53 may be provided or omitted as necessary.

[0020] In this embodiment, the number of terminal holes 51 provided in the case 50 is greater than the number of external terminals 60. Of the plurality of terminal holes 51, an external terminal 60 is inserted into each of the plurality of terminal holes 51, the number of which corresponds to the number of external terminals 60, but no external terminals 60 are inserted into the remaining terminal holes 51. In this way, the reason why the number of terminal holes 51 provided in the case 50 is greater than the number of external terminals 60 is to enable the case 50 to be used with semiconductor modules having different terminal positions. Note that the arrangement and number of the plurality of terminal holes 51 are not limited to the example shown in FIG. 1 and are arbitrary. Furthermore, the number of terminal holes 51 may be equal to the number of external terminals 60.

[0021] Each of the plurality of external terminals 60 is a terminal for electrically connecting the semiconductor chip 30 to a substrate (not shown) on which the semiconductor module 10 is mounted. Here, each external terminal 60 is arranged inside and outside the case 50 through a terminal hole 51, and is electrically connected to the semiconductor chip 30. The plurality of external terminals 60 are made of a metal such as copper, a copper alloy, aluminum, an aluminum alloy, or an iron alloy. Furthermore, the surfaces of the external terminals 60 may be plated with, for example, Sn plating or Sn-Cu plating.

[0022] Of the multiple external terminals 60 that the semiconductor module 10 has, two or more external terminals 60 are main terminals through which a main current flows, and the other two or more external terminals 60 are control terminals for controlling the operation of the semiconductor chip 30. The main terminals are external terminals 60-M shown in Fig. 2, which will be described later, and the control terminals are external terminals 60-C shown in Fig. 3, which will be described later. Details of the external terminals 60 will be described later with reference to Figs. 2 to 6.

[0023] The spacer 70 is an insulating frame-shaped member interposed between the insulating substrate 20 and the case 50. The spacer 70 has the function of pressing the plurality of external terminals 60 against the case 50 and the function of ensuring electrical insulation between each of the plurality of external terminals 60 and the insulating substrate 20. The spacer 70 is essentially an insulator and, like the case 50, is made of a resin material such as PPS (Polyphenylene Sulfide) or PBT (Polybutylene Terephthalate). Note that the resin material may contain an inorganic filler such as alumina or silica to improve the mechanical strength of the spacer 70. The material constituting the spacer 70 is not limited to a resin material and may be, for example, a ceramic material.

[0024] In the example shown in Fig. 1, the thickness direction of the spacer 70 is along the Z axis. The surface of the spacer 70 facing the Z1 direction is bonded to the case 50 with an adhesive. On the other hand, the surface of the spacer 70 facing the Z2 direction is bonded to the insulating substrate 20 with an adhesive. The shape of the spacer 70 is not limited to the example shown in Fig. 1 and may be any shape.

[0025] The lid 80 is a plate-like member bonded to the surface of the case 50 facing the Z1 direction. Like the case 50, the lid 80 is made of a resin material such as PPS (Polyphenylene Sulfide) or PBT (Polybutylene Terephthalate). The lid 80 is bonded to the case 50 with an adhesive or the like so as to seal the gap between the lid 80 and the case 50. The lid 80 is provided as needed and may be omitted.

[0026] Here, although not shown, the space surrounded by the base plate 40, the case 50, and the lid 80 is filled with a potting material that covers the semiconductor chip 30. The potting material is made of, for example, a silicone resin such as silicone gel or an epoxy resin.

[0027] 1-2. External terminals and insulating substrate 2 to 4 are cross-sectional views of a semiconductor module 10 according to an embodiment. FIG. 2 shows an electrical connection between an external terminal 60-M1 and a semiconductor chip 30. The external terminal 60-M1 is one of the multiple external terminals 60 that is used as an input main terminal. FIG. 3 shows an electrical connection between an external terminal 60-M2 and a semiconductor chip 30. The external terminal 60-M2 is one of the multiple external terminals 60 that is used as an output main terminal. FIG. 4 shows an electrical connection between an external terminal 60-C and a semiconductor chip 30. The external terminal 60-C is one of the multiple external terminals 60 that is used as a control terminal. Hereinafter, the external terminals 60-M1, 60-M2, and 60-C may be referred to as external terminals 60 without distinction. Note that for ease of explanation, the shapes of the external terminals 60 are illustrated simply in FIGS. 2 to 4.

[0028] As shown in FIGS. 2 to 4, the insulating substrate 20 has an insulating plate 21, a conductive plate 22, and a conductive pattern 23.

[0029] The insulating plate 21 is an insulating plate-like member arranged with its thickness direction aligned along the Z axis. The insulating plate 21 is made of ceramics such as aluminum nitride, aluminum oxide, or silicon nitride. When viewed along the Z axis, the insulating plate 21 is arranged not only inside the case 50 but also in the area overlapping the case 50.

[0030] The conductive plate 22 is a plate-shaped conductor arranged over substantially the entire surface of the insulating plate 21 facing the Z2 direction. The conductive plate 22 is made of a metal such as copper or aluminum. The base plate 40 is joined to the conductive plate 22 with a joining material B0 such as solder.

[0031] The conductive pattern 23 is disposed on one surface of the insulating plate 21 and includes a conductor 23a that is bonded to the semiconductor chip 30. In this embodiment, the conductive pattern 23 is disposed on the surface of the insulating plate 21 facing the Z1 direction and includes a plurality of conductors 23a, 23b, and 23c that are separated from one another. Like the conductive plate 22, the conductive pattern 23 is made of a metal such as copper or aluminum. A plurality of semiconductor chips 30 are bonded to the conductive pattern 23 with a bonding material such as solder.

[0032] 2 and 3, the conductor 23a is a conductor joined to the semiconductor chip 30, and is electrically connected to the input electrode of the semiconductor chip 30. The electrical connection between the conductor 23a and the input electrode of the semiconductor chip 30 is achieved by joining the conductor 23a and the input electrode of the semiconductor chip 30 to each other with solder or the like. Also, as shown in FIG. 2, the conductor 23a has a portion located directly below the external terminal 60-M1, and this portion comes into contact with a connection portion 63 of the external terminal 60-M1, which will be described later.

[0033] 3, the conductor 23b is not bonded to the semiconductor chip 30 and is electrically connected to an output electrode of the semiconductor chip 30. The electrical connection between the conductor 23b and the output electrode of the semiconductor chip 30 is achieved by connecting the conductor 23b and the output electrode of the semiconductor chip 30 to each other via a bonding wire BW1. The conductor 23b also has a portion located directly below the external terminal 60-M2, and this portion comes into contact with a connection portion 63 of the external terminal 60-M2, which will be described later.

[0034] 4, the conductor 23c is a conductor that is not joined to the semiconductor chip 30. The conductor 23c has a portion that is disposed directly below the external terminal 60-C, and this portion comes into contact with a connection portion 63 (described later) of the external terminal 60-C.

[0035] The external terminals 60 used as the external terminals 60-M1, 60-M2, and 60-C are made of a metal plate bent roughly into an L-shape. More specifically, the external terminals 60 have a pin portion 61, a leg portion 62, and a connection portion 63, as shown in Figures 2 to 4.

[0036] The pin portion 61 is a part of the external terminal 60 and is a rod-shaped portion that extends toward the outside of the case 50 along the thickness direction of the insulating substrate 20. In the example shown in FIGS. 2 to 4, the pin portion 61 extends in a direction along the Z axis. The end of the pin portion 61 in the Z1 direction protrudes from the outer wall surface of the case 50. In this manner, the pin portion 61 has a terminal portion that protrudes from the outer wall surface of the case 50. The terminal portion is connected to a board (not shown) on which the semiconductor module 10 is mounted. The leg portion 62 and the connection portion 63 are connected to the pin portion 61.

[0037] The leg portion 62 is a part of the external terminal 60 and is a plate-like portion extending toward the inside of the case 50 in a direction intersecting the extension direction of the pin portion 61. In this embodiment, the leg portion 62 is arranged along the surface of the spacer 70 facing the Z1 direction. The leg portion 62 extends toward the inside of the case 50 from the end of the pin portion 61 in the Z2 direction. The leg portion 62 has a portion sandwiched between the case 50 and the spacer 70 and a pad portion that is exposed inside the case 50. In the external terminal 60-C, one end of a bonding wire BW2 is bonded to the pad portion, as shown in FIG. 4 . The other end of the bonding wire BW2 is bonded to the control electrode of the semiconductor chip 30. In this manner, the external terminal 60-C and the control electrode of the semiconductor chip 30 are electrically connected to each other via the bonding wire BW2. That is, the external terminal 60-C, which is a control terminal, is electrically connected to the control electrode of the semiconductor chip 30 via the bonding wire BW2 joined to the leg portion 62.

[0038] The other end of the bonding wire BW2 may be joined to one of the plurality of conductors constituting the conductor pattern 23 of the insulating substrate 20 that is electrically connected to the control electrode of the semiconductor chip 30. Furthermore, even in the case of the external terminal 60-M1, one end of the bonding wire may be joined to the pad portion as needed. In this case, the other end of the bonding wire is joined to the conductor 23a, or to one of the plurality of conductors constituting the conductor pattern 23 of the insulating substrate 20 that is electrically connected to the conductor 23a. Similarly, even in the case of the external terminal 60-M2, one end of the bonding wire may be joined to the pad portion as needed. In this case, the other end of the bonding wire is joined to the output electrode of the semiconductor chip 30, or to one of the plurality of conductors constituting the conductor pattern 23 of the insulating substrate 20 that is electrically connected to the output electrode of the semiconductor chip 30.

[0039] Here, the surface of the spacer 70 facing the Z1 direction is bonded to the surface of the leg 62 facing the Z2 direction and to the case 50 with an adhesive (not shown). The surface of the spacer 70 facing the Z2 direction is bonded to the surface of the insulating substrate 20 facing the Z1 direction with an insulating adhesive B1. Furthermore, the base plate 40 and the case 50 are bonded with an insulating adhesive B2. Examples of adhesives B1 and B2 include epoxy adhesives or silicone adhesives containing inorganic fillers such as silica or alumina. Note that the adhesives B1 and B2 may be the same or different. Furthermore, the adhesives B1 and B2 may be integrated.

[0040] In this way, insulating spacers 70 are interposed between the legs 62 and the insulating substrate 20. This ensures the necessary electrical insulation between the external terminals 60 and the conductive patterns 23, and enables the external terminals 60 to be stably fixed to the case 50. Note that the spacers 70 are provided as needed, and may be omitted.

[0041] The connecting portion 63 is a part of the external terminal 60 and extends from the pin portion 61 toward the insulating substrate 20 along the thickness direction of the insulating substrate 20. In the example shown in FIGS. 2 to 4, the connecting portion 63 protrudes from the pin portion 61 in the Z2 direction. The protrusion amount of the connecting portion 63 is greater than the thickness of the spacer 70. As a result, the end of the connecting portion 63 in the Z1 direction is located further in the Z2 direction than the spacer 70. Furthermore, the end of the connecting portion 63 in the Z2 direction contacts the conductive pattern 23 of the insulating substrate 20. More specifically, in the external terminal 60-M1, as shown in FIG. 2, the end of the connecting portion 63 in the Z2 direction contacts the conductor 23a. In the external terminal 60-M2, as shown in FIG. 3, the end of the connecting portion 63 in the Z2 direction contacts the conductor 23b. In the external terminal 60-C, as shown in FIG. 4, the end of the connecting portion 63 in the Z2 direction contacts the conductor 23c.

[0042] The connecting portions 63 come into contact with the conductive patterns 23 when subjected to the compressive force between the insulating substrate 20 and the case 50. This allows the external terminals 60 to be electrically connected to the conductive patterns 23. This allows the number of bonding wires for electrically connecting the external terminals 60 and the semiconductor chip 30 to be reduced.

[0043] Specifically, contact between the connection portion 63 of the external terminal 60-M1 and the conductor 23a allows the external terminal 60-M1 to be electrically connected to the input electrode of the semiconductor chip 30 without using a bonding wire bonded to the external terminal 60-M1 and the insulating substrate 20. Contact between the connection portion 63 of the external terminal 60-M2 and the conductor 23b allows the external terminal 60-M2 to be electrically connected to the output electrode of the semiconductor chip 30 without using a bonding wire bonded to the external terminal 60-M2 and the insulating substrate 20. Bonding wires may be used to bond the external terminals 60-M1, 60-M2 and the insulating substrate 20. Even in this case, the main current path is secured by contact between the connection portion 63 and the conductor pattern 23, so the number of bonding wires can be reduced compared to an embodiment that does not use the connection portion 63.

[0044] In this way, the connection portion 63 of the external terminal 60-M1, which is a main terminal electrically connected to the main current path of the semiconductor chip 30, contacts the conductor 23a, among the multiple conductors 23a, 23b, and 23c, which is electrically connected to the main current path of the semiconductor chip 30. Similarly, the connection portion 63 of the external terminal 60-M2, which is a main terminal electrically connected to the main current path of the semiconductor chip 30, contacts the conductor 23b, among the multiple conductors 23a, 23b, and 23c, which is electrically connected to the main current path of the semiconductor chip 30. Due to this contact between the external terminals 60-M1 and 60-M2 and the conductor pattern 23, the external terminals 60-M1 and 60-M2 can be electrically connected to the main current path of the semiconductor chip 30 while reducing the number of bonding wires.

[0045] Moreover, since the insulating substrate 20 extends to just below the connection portions 63 of the external terminals 60, combined with the effect of reducing the number of bonding wires described above, a larger area can be secured on the insulating substrate 20 for mounting the semiconductor chip 30 compared to an embodiment that does not use the connection portions 63. This allows the semiconductor chip 30 to be enlarged while the case 50 is made smaller. This allows the current rating of the semiconductor module 10 to be increased while the semiconductor module 10 is made smaller.

[0046] Furthermore, heat generated when current is applied to the external terminals 60 can be efficiently dissipated from the connection portions 63 to the base plate 40 via the insulating substrate 20. This allows an increase in the current that can flow through each external terminal 60. As a result, the current rating of the semiconductor module 10 can be increased without increasing the number of external terminals 60. Furthermore, by utilizing the space gained by reducing the number of external terminals 60 in this way, functions can be added to the semiconductor module 10. For example, an auxiliary emitter terminal and an auxiliary collector terminal can be added, or if a shunt resistor is built in, a terminal for sensing the resistance value of the shunt resistor can be added.

[0047] Furthermore, the connection portion 63 of the external terminal 60-C, which is a control terminal, contacts, among the multiple conductors 23a, 23b, and 23c, a conductor 23c that is different from the conductors 23a and 23b that are electrically connected to the main current path of the semiconductor chip 30. This allows the external terminal 60-C to be electrically connected to the semiconductor chip 30 without complicating the conductor pattern 23. Here, the current capacity of the external terminal 60-C, which is a control terminal, is significantly smaller than the current capacity of the external terminals 60-M1 and 60-M2, which are main terminals, and therefore fewer bonding wires BW2 are required.

[0048] The above-described connection portion 63 receives the compressive force between the insulating substrate 20 and the case 50, thereby stabilizing the contact state between the connection portion 63 and the conductive pattern 23.

[0049] Fig. 5 is a perspective view of an external terminal 60 in an embodiment. Fig. 6 is a diagram for explaining a manufacturing example of the external terminal 60. Fig. 5 shows an example of the external terminal 60 manufactured by bending a metal plate. Fig. 6 shows the external terminal 60 manufactured by bending a metal plate in a state before bending.

[0050] As shown in FIG. 5 , the pin portion 61 has a first portion 61a and a second portion 61b. The first portion 61a is a portion of the pin portion 61 that is accommodated in the terminal hole 51 of the case 50. The second portion 61b is a portion of the pin portion 61 that extends in the Z1 direction from the Z1-direction end of the first portion 61a and includes a terminal portion that protrudes outside the case 50. The width of the second portion 61b is narrower than the width of the first portion 61a. This provides the first portion 61a with a pair of shoulders SH formed by surfaces facing the Z1 direction. Although not shown, the terminal hole 51 has a surface that contacts the pair of shoulders SH. This allows the connection portion 63 of the external terminal 60 to receive a compressive force between the case 50 and the insulating substrate 20.

[0051] The shape of the pin portion 61 is not limited to the examples shown in FIGS. 5 and 6, and may be, for example, a shape in which the second portion 61b is branched into two portions.

[0052] The leg portion 62 is connected to a side surface of the first portion 61a near an end of the first portion 61a in the Z2 direction. In this embodiment, the external terminal 60 is manufactured by bending a metal plate, and by bending the external terminal 60 along a bending line LN that intersects with the Z axis, the leg portion 62 extends in a direction intersecting with the extension direction of the pin portion 561. Note that the shape of the leg portion 62 is not limited to the example shown in FIG. 5 and may be, for example, a shape of a constant width.

[0053] A connecting portion 63 is connected to the end of the first portion 61a in the Z2 direction. As shown in Fig. 5, the connecting portion 63 has a spring shape that is elastically deformable in the direction along the Z axis, i.e., in the thickness direction of the insulating substrate 20. This makes it possible to maintain a stable contact state between the conductive pattern 23 and the connecting portion 63 while preventing the insulating substrate 20 from being subjected to pressure that would cause cracks.

[0054] The connecting portion 63 is provided with a plurality of slits SL extending in a direction intersecting the thickness direction of the insulating substrate 20. This allows the external terminal 60 having the spring-shaped connecting portion 63 to be easily manufactured by processing such as punching a metal plate.

[0055] In the example shown in FIG. 5, two slits SL are aligned in the direction along the Z axis, and the two slits SL open in opposite directions. The number of slits SL is not limited to the example shown in FIG. 5 and may be one or three or more. The direction in which the slits SL extend is not limited to a direction perpendicular to the Z axis and may be, for example, a direction inclined relative to the direction perpendicular to the Z axis. The shape of the slits SL is not limited to the example shown in FIG. 5 and may be, for example, a curved shape or a shape with a variable width.

[0056] The external terminals 60 as described above are manufactured by punching a metal plate, and then inserted into the terminal holes 51 of the case 50. After that, an adhesive is applied to the surfaces of the legs 62 facing the Z2 direction, and then the spacers 70 are fitted inside the case 50. In this way, the external terminals 60 are fixed to the case 50.

[0057] Meanwhile, a laminate is manufactured in which the base plate 40, the semiconductor chip 30, and the insulating substrate 20 are stacked by soldering. This laminate is then inserted into the case 50, which incorporates the external terminals 60 and the spacer 70, as described above, and bonded. This bonding is performed with pressure applied between the case 50 and the base plate 40. This allows the external terminals 60 to be fixed in a pressed state against the insulating substrate 20. Here, because the connecting portions 63 have a spring shape as described above, the connecting portions 63 deform appropriately according to the amount of pressure the base plate 40 places on the case 50.

[0058] Thereafter, wire bonding is performed appropriately inside the case 50, and then the case 50 is filled with a potting material, and the lid 80 is adhered to the case 50. In this way, the semiconductor module 10 is obtained.

[0059] As described above, in the semiconductor module 10, the connection portions 63 of the external terminals 60 contact the conductive patterns 23, thereby reducing the number of bonding wires for electrically connecting the external terminals 60 and the semiconductor chip 30. Moreover, coupled with the insulating substrate 20 extending to directly below the connection portions 63 of the external terminals 60, this allows the semiconductor module 10 to be miniaturized while increasing its current rating. Furthermore, by efficiently dissipating heat generated when current is applied to the external terminals 60 from the connection portions 63 via the insulating substrate 20 to the base plate 40, the current rating of the semiconductor module 10 can be increased without increasing the number of external terminals 60.

[0060] 2. Variations The present disclosure is not limited to the above-described embodiments, and various modifications are possible as described below. Furthermore, the embodiments and modifications may be combined as appropriate.

[0061] 2-1. Variation 1 Fig. 7 is a cross-sectional view of the semiconductor module 10 according to Modification 1. Fig. 7 shows another example of the electrical connection between the semiconductor chip 30 and the external terminal 60-C used as the control terminal.

[0062] When there are multiple control terminals, the connection mode shown in Fig. 4 and the connection mode shown in Fig. 7 may be used in combination as appropriate. In the connection mode shown in Fig. 7, conductor pattern 23 includes conductor 23d in addition to the multiple conductors 23a, 23b, and 23c described above. Note that the connection mode shown in Fig. 7 may be used instead of the connection mode shown in Fig. 4.

[0063] 7, the conductor 23d is a conductor that is not bonded to the semiconductor chip 30, and is electrically connected to the control electrode of the semiconductor chip 30. The electrical connection between the conductor 23d and the control electrode of the semiconductor chip 30 is achieved by connecting the conductor 23d and the control electrode of the semiconductor chip 30 to each other via a bonding wire BW3. The conductor 23d also has a portion that is located directly below the external terminal 60-C, and this portion makes contact with the connection portion 63 of the external terminal 60-C.

[0064] According to the above-described first modification, the current rating of the semiconductor module 10 can be increased while achieving miniaturization.

[0065] 2-2. Variation 2 In the above-described embodiment, an example is given in which all of the multiple external terminals 60 of the semiconductor module 10 have the connection portion 63, but this is not limited to this, and the semiconductor module 10 may also have external terminals that do not have the connection portion 63. The external terminals that do not have the connection portion 63 are not particularly limited, and for example, various known external terminals can be applied.

[0066] 2-3. Variation 3 In the above-described embodiment, an example is given in which the external terminal 60 is manufactured by punching a metal plate, but the present invention is not limited to this example. For example, the external terminal 60 may be manufactured by manufacturing one or both of the leg portion 62 and the connecting portion 63 by a process separate from that for the pin portion 61, and then joining them to the pin portion 61 by welding or the like. In this case, the position of the central axis of the connecting portion 63 in the width direction can be made to coincide with the position of the central axis of the pin portion 61 in the width direction.

[0067] 4. Notes For example, the following aspects can be understood from the above embodiment and modified examples.

[0068] (Appendix 1) A first aspect, which is a preferred example of a semiconductor module of the present disclosure, comprises a base plate, an insulating substrate arranged on one surface of the base plate and on which a semiconductor chip is provided, a frame-shaped case surrounding the insulating substrate, and a plurality of external terminals arranged inside and outside the case and electrically connected to the semiconductor chip, wherein the insulating substrate has an insulating plate and a conductor pattern arranged on one surface of the insulating plate and including conductors joined to the semiconductor chip, and at least one external terminal of the plurality of external terminals has a pin portion extending toward the outside of the case in a thickness direction of the insulating substrate, a leg portion extending toward the inside of the case in a direction intersecting the extension direction of the pin portion, and a connection portion extending from the pin portion toward the insulating substrate in the thickness direction of the insulating substrate, and the connection portion contacts the conductor pattern when subjected to a compressive force between the insulating substrate and the case.

[0069] In the above-described embodiment, the connecting portions of the external terminals come into contact with the conductor patterns while being subjected to the compressive force between the insulating substrate and the case, thereby electrically connecting the external terminals to the conductor patterns, thereby reducing the number of bonding wires required to electrically connect the external terminals to the semiconductor chip.

[0070] Furthermore, because the insulating substrate extends to just below the connection portion of the external terminal, combined with the effect of reducing the number of bonding wires mentioned above, it is possible to increase the size of the semiconductor chip while miniaturizing the case, which makes it possible to increase the current rating of the semiconductor module while miniaturizing the semiconductor module.

[0071] Furthermore, heat generated when current is applied to the external terminals can be efficiently dissipated from the connection section to the base plate via the insulating substrate. This increases the current that can be passed through each external terminal. As a result, the current rating of the semiconductor module can be increased without increasing the number of external terminals.

[0072] (Appendix 2) In a second aspect which is a preferred example of the first aspect, the at least one external terminal includes a control terminal as an external terminal which is electrically connected to a control electrode of the semiconductor chip via a bonding wire joined to the leg portion, the conductor pattern includes a plurality of conductors which are separated from one another, and the connection portion of the control terminal contacts a conductor of the plurality of conductors which is different from a conductor electrically connected to a main current path of the semiconductor chip.

[0073] In the above-described embodiment, the control terminal can be electrically connected to the semiconductor chip without complicating the conductor pattern. Here, the current capacity of the control terminal is significantly smaller than that of the main terminal, so fewer bonding wires are required. Furthermore, the connection portion of the control terminal contacts a conductor different from the conductor electrically connected to the main current path of the semiconductor chip, thereby ensuring the function of the control terminal and contributing to heat dissipation of the control terminal and other external terminals.

[0074] (Appendix 3) In a third aspect which is a preferred example of the first or second aspect, the at least one external terminal includes a main terminal electrically connected to a main current path of the semiconductor chip, the conductor pattern includes a plurality of conductors separated from one another, and the connection portion of the main terminal contacts the conductor among the plurality of conductors which is electrically connected to the main current path of the semiconductor chip.

[0075] In the above-described embodiment, the main terminal can be electrically connected to the main current path of the semiconductor chip while reducing the number of bonding wires.

[0076] (Supplementary Note 4) In a fourth aspect which is a suitable example of any one of the first to third aspects, the connection portion has a spring shape which is elastically deformable in a thickness direction of the insulating substrate.

[0077] In the above-described embodiment, it is possible to prevent the insulating substrate from being subjected to pressure that would cause cracks, while maintaining a stable contact state between the conductive pattern and the connecting portion.

[0078] (Supplementary Note 5) In a fifth aspect which is a preferred example of the fourth aspect, the connection portion is provided with a slit extending in a direction intersecting the thickness direction of the insulating substrate.

[0079] In the above embodiment, an external terminal having a spring-shaped connecting portion can be easily manufactured by processing such as punching a metal plate.

[0080] (Supplementary Note 6) In a sixth aspect which is a suitable example of any one of the first to fifth aspects, an insulating spacer is further provided between the leg portion and the insulating substrate.

[0081] In the above-described embodiment, it is possible to ensure the necessary electrical insulation between the external terminals and the conductor patterns, and to stably fix the external terminals to the case. [Explanation of symbols]

[0082] 10...semiconductor module, 20...insulating substrate, 21...insulating plate, 22...conductor plate, 23...conductor pattern, 23a...conductor, 23b...conductor, 23c...conductor, 23d...conductor, 30...semiconductor chip, 40...base plate, 41...mounting hole, 50...case, 51...terminal hole, 52...hole, 53...hole, 60...external terminal, 60-C...external terminal, 60-M...external terminal, 60-M1...external terminal, 60-M2...external terminal, 61...pin portion, 61a...first portion, 61b...second portion, 62...leg portion, 63...connection portion, 70...spacer, 80...lid, 561...pin portion, B0...bonding material, B1...adhesive, B2...adhesive, BW1...bonding wire, BW2...bonding wire, BW3...bonding wire, LN...bending line, SH...shoulder, SL...slit.

Claims

1. A base plate and an insulating substrate disposed on one surface of the base plate and on which a semiconductor chip is provided; a frame-shaped case surrounding the insulating substrate; a plurality of external terminals arranged inside and outside the case and electrically connected to the semiconductor chip; The insulating substrate is An insulating plate; a conductor pattern disposed on one surface of the insulating plate and including a conductor to be bonded to the semiconductor chip; At least one external terminal of the plurality of external terminals is a pin portion extending toward the outside of the case along a thickness direction of the insulating substrate; a leg portion extending toward the inside of the case in a direction intersecting the direction in which the pin portion extends; a connection portion extending from the pin portion toward the insulating substrate along a thickness direction of the insulating substrate, the connecting portion contacts the conductor pattern while receiving a compressive force between the insulating substrate and the case. Semiconductor module.

2. the at least one external terminal includes a control terminal electrically connected to a control electrode of the semiconductor chip via a bonding wire joined to the leg portion; the conductor pattern includes a plurality of conductors separated from one another; the connection portion of the control terminal contacts one of the plurality of conductors that is different from a conductor electrically connected to a main current path of the semiconductor chip; The semiconductor module according to claim 1 .

3. the at least one external terminal includes a main terminal electrically connected to a main current path of the semiconductor chip; the conductor pattern includes a plurality of conductors separated from one another; the connection portion of the main terminal contacts a conductor, among the plurality of conductors, that is electrically connected to a main current path of the semiconductor chip; 3. The semiconductor module according to claim 1.

4. the connecting portion has a spring shape that is elastically deformable in a thickness direction of the insulating substrate; The semiconductor module according to claim 1 .

5. The connection portion is provided with a slit extending in a direction intersecting the thickness direction of the insulating substrate. The semiconductor module according to claim 4 .

6. further comprising an insulating spacer interposed between the leg portion and the insulating substrate; The semiconductor module according to claim 1 .

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