Semiconductor module, manufacturing method for semiconductor module, and case unit

Abstract

To reduce damage to a semiconductor module even if the semiconductor module is used in a corrosive gas atmosphere.SOLUTION: A semiconductor module includes: a semiconductor element; a laminated plate including a wiring board on which the semiconductor element is mounted; a case including a plurality of terminal holes, the case housing the semiconductor element; a plurality of external terminals, each external terminal being inserted into one of two or more terminal holes among the plurality of terminal holes, the plurality of external terminals being electrically connected to the semiconductor element; and a spacer interposed between the laminated plate and the case. The case and the spacer are bonded to each other by an adhesive. Each of the plurality of external terminals has a first bonding surface bonded to the spacer by the adhesive. The case includes a partition wall between the two adjacent terminal holes among the plurality of terminal holes. A distance between the first bonding surface and the partition wall is greater than a thickness of each external terminal.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a semiconductor module, a method for manufacturing a semiconductor module, and a case unit. [Background technology]

[0002] A semiconductor module, typified by a power semiconductor module, generally includes a semiconductor element, a laminate including a wiring board on which the semiconductor element is mounted, a case that houses the semiconductor element, and a plurality of external terminals that are electrically connected to the semiconductor element. For example, as disclosed in Patent Document 1, the case is provided with a plurality of terminal holes that penetrate the case. Each external terminal is inserted into one of the plurality of terminal holes and has a portion that protrudes from the outer wall surface of the case.

[0003] In Patent Document 1, the laminate has a wiring board and a base for heat dissipation, and a terminal retaining frame is disposed between the case and the base to press the external terminals toward the case. The terminal retaining frame is bonded to both the case and the base with an adhesive. In Patent Document 1, gaps are provided between the terminal retaining frame and the external terminals and between the terminal retaining frame and the case, respectively, so that the adhesive applied to the bottom surface of the terminal retaining frame flows into each gap. Here, the case is provided with terminal holes in a number and positions that are designed to allow the case to be used for multiple types of semiconductor modules. As a result, there are cases where external terminals are not inserted into one or more of the multiple terminal holes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-92388 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for a semiconductor module that can be used for a long period of time even in a corrosive gas atmosphere.

[0006] In the configuration described in Patent Document 1, when the case and the terminal retaining frame are joined together with an adhesive, the partition separating two adjacent terminal holes prevents the adhesive from spreading. This means that the amount of adhesive supplied to each terminal hole is easily affected by variations in the amount of adhesive applied depending on the application position. As a result, it is difficult to reliably seal the terminal holes, especially those without external terminals, with adhesive. Therefore, with the configuration described in Patent Document 1, when a semiconductor module is used in a corrosive gas atmosphere, corrosive gas may enter the case through the terminal holes and damage the semiconductor module.

[0007] In consideration of the above circumstances, one aspect of the present disclosure aims to reduce damage to a semiconductor module even when used in a corrosive gas atmosphere. [Means for solving the problem]

[0008] In order to solve the above problems, a semiconductor module according to a preferred embodiment of the present disclosure comprises: a semiconductor element; a laminated plate including a wiring substrate on which the semiconductor element is mounted; a case having a plurality of terminal holes and accommodating the semiconductor element; a plurality of external terminals inserted into two or more of the plurality of terminal holes and electrically connected to the semiconductor element; and a spacer interposed between the laminated plate and the case, wherein the case and the spacer are joined to each other with an adhesive, and each of the plurality of external terminals has a first bonding surface joined to the spacer with the adhesive, and the case has a partition wall provided between two adjacent terminal holes of the plurality of terminal holes, wherein the distance between the partition wall and the first bonding surface of the two or more terminal holes is greater than the thickness of each of the plurality of external terminals, and the distance between the partition wall and the spacer of terminal holes other than the two or more terminal holes of the plurality of terminal holes is equal to or greater than the distance between the partition wall and the spacer of the two or more terminal holes.

[0009] A method for manufacturing a semiconductor module according to a preferred embodiment of the present disclosure includes a preparation step of preparing a case having a plurality of terminal holes, a terminal insertion step of inserting a plurality of external terminals into two or more of the plurality of terminal holes, and a joining step of joining the case and a spacer to each other with an adhesive, wherein each of the plurality of external terminals has a first joining surface joined to the spacer with the adhesive, the case has a partition wall provided between two adjacent terminal holes among the plurality of terminal holes, the distance between the first joining surface and the partition wall is greater than the thickness of each of the plurality of external terminals, and in the joining step, each of the plurality of terminal holes is sealed with the adhesive.

[0010] A case unit according to a preferred embodiment of the present disclosure comprises a case having a plurality of terminal holes, a plurality of external terminals to be inserted into two or more of the plurality of terminal holes, and a spacer bonded to the case with an adhesive, wherein each of the plurality of external terminals has a first bonding surface bonded to the spacer with the adhesive, the case has a partition wall provided between two adjacent terminal holes of the plurality of terminal holes, the distance between the first bonding surface and the partition wall is greater than the thickness of each of the plurality of external terminals, and each of the plurality of terminal holes is sealed with the adhesive. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an exploded perspective view of a semiconductor module according to a first embodiment. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] 3 is a cross-sectional view of the semiconductor module taken along line AA in FIG. 2. [Figure 5] 3 is a cross-sectional view of the semiconductor module taken along line BB in FIG. 2. [Figure 6] 3 is a cross-sectional view of the semiconductor module taken along line CC in FIG. 2. [Figure 7] 4 is a flowchart showing a method for manufacturing the semiconductor module according to the first embodiment. [Figure 8] FIG. 10 is a diagram for explaining a preparation step. [Figure 9] 10A and 10B are diagrams for explaining a terminal insertion step. [Figure 10] FIG. 10 is a diagram for explaining a coating step during the bonding step. [Figure 11] FIG. 10 is a diagram for explaining a bonding step in the joining step. [Figure 12] FIG. 10 is a diagram for explaining a softening step during the joining step. [Figure 13] FIG. 10 is an exploded perspective view of a semiconductor module according to a second embodiment. [Figure 14] FIG. 10 is a cross-sectional view of a semiconductor module according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] 1. First embodiment 1-1. Overall configuration of semiconductor module 1 is an exploded perspective view of a semiconductor module 10 according to a first 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.

[0014] As shown in FIG. 1, a semiconductor module 10 includes a plurality of semiconductor elements 30, a wiring board 20, a base 40, a case 50, a plurality of external terminals 60, a spacer 70, and a lid 80. In FIG. 1, the semiconductor elements 30 are not shown, and the outline of the wiring board 20 is simply indicated by a two-dot chain line. Here, the wiring board 20 and the base 40 form a laminated plate 11. The laminated plate 11 is a plate-shaped laminate having at least the wiring board 20. In this embodiment, the laminated plate 11 has the wiring board 20 and the base 40. Furthermore, the case 50, the plurality of external terminals 60, and the spacer 70 form a case unit 12. The case unit 12 is an assembly formed by assembling the case 50, the plurality of external terminals 60, and the spacer 70.

[0015] First, the outline of each part of the semiconductor module 10 will be sequentially described below with reference to FIG. 1. For convenience, the following description will appropriately use the mutually orthogonal X-axis, Y-axis, and Z-axis. 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."

[0016] The wiring board 20 is a substrate on which multiple semiconductor elements 30 are mounted and forms a circuit together with the multiple semiconductor elements 30. For example, the wiring board 20 is a substrate such as a DCB (Direct Copper Bonding) substrate or a DBA (Direct Bonded Aluminum) substrate. Although not shown, the wiring board 20 has an insulating substrate and two conductor layers provided on both sides of the insulating substrate. The insulating substrate is made of ceramics such as aluminum nitride, aluminum oxide, or silicon nitride. Each of the two conductor layers is made of metal such as copper or aluminum. The multiple semiconductor elements 30 are bonded to one of the two conductor layers by solder or the like. Furthermore, the base 40 is bonded to the other of the two conductor layers by solder or the like.

[0017] 1, the thickness direction of the wiring board 20 is along the Z axis. A plurality of semiconductor elements 30 are bonded to the surface of the wiring board 20 facing the Z1 direction with a conductive bonding material such as solder. On the other hand, a base 40 is bonded to the surface of the wiring board 20 facing the Z2 direction with a conductive bonding material such as solder.

[0018] At least one element of the plurality of semiconductor elements 30 mounted on the wiring board 20 is a power semiconductor chip such as an IGBT. Note that, in addition to the power semiconductor chip, the wiring board 20 may also mount a control chip for controlling the operation of the power semiconductor chip as the semiconductor element 30, or an element such as an FWD (Free Wheeling Diode) for commutating a load current.

[0019] The base 40 is a plate-like member for heat dissipation. For example, the base 40 is a metal plate made of copper, a copper alloy, aluminum, or an aluminum alloy. The base 40 has thermal conductivity and dissipates heat from the semiconductor element 30. The base 40 also has electrical conductivity and is electrically connected to a reference potential such as a ground potential.

[0020] In the example shown in FIG. 1 , the thickness direction of the base 40 is along the Z-axis. When viewed in the direction along the Z-axis, the base 40 has a shape having a pair of long sides extending in the direction along the X-axis and a pair of short sides extending in the direction along the Y-axis. The base 40 has mounting holes 41 formed near each of the short sides. 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 40. The planar shape and number of the base 40 are not limited to the example shown in FIG. 1 and are arbitrary.

[0021] The case 50 is a frame-shaped member that houses a plurality of semiconductor elements 30 mounted on the wiring board 20. The case 50 is essentially an insulator and is made of a resin material such as PPS (Polyphenylene Sulfide) or PBT (Polybutylene Terephthalate). The resin material may contain an inorganic filler such as alumina or silica in order to improve the mechanical strength or thermal conductivity of the case 50.

[0022] The case 50 has a plurality of terminal holes 51 arranged along the circumferential direction of the case 50. Each terminal hole 51 is a hole that penetrates the case 50. In the example shown in Fig. 1, each terminal hole 51 extends in a direction along the Z axis.

[0023] 1, the thickness direction of case 50 is along the Z axis. When viewed in the direction along the Z axis, 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. The multiple terminal holes 51 provided in case 50 are divided into multiple terminal holes 51 arranged along each long side and multiple terminal holes 51 arranged along each short side.

[0024] An external terminal 60 is inserted into each of two or more of the multiple terminal holes 51 provided in the case 50. Therefore, the number of terminal holes 51 provided in the case 50 is equal to or greater than the number of external terminals 60. The reason why the number of terminal holes 51 provided in the case 50 is greater than the number of external terminals 60 is so that the case 50 can be used with semiconductor modules having multiple types of terminal positions. Furthermore, the number of terminal holes 51 provided in the case 50 can be determined in advance based on the number and arrangement of the external terminals 60 of the semiconductor module so that the case 50 can be used with the multiple types of terminal positions. Note that the arrangement and number of the multiple terminal holes 51 are not limited to the example shown in FIG. 1 and are arbitrary.

[0025] Each of the plurality of external terminals 60 is a terminal for electrically connecting a substrate (not shown) on which the semiconductor module 10 is mounted to the semiconductor element 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.

[0026] Here, of the multiple external terminals 60 that the semiconductor module 10 has, two or more external terminals 60 are terminals through which the main current flows, and the other two or more external terminals 60 are control terminals for controlling the operation of the semiconductor element 30.

[0027] 1, the external terminal 60 is made of a metal plate bent into an L-shape. Here, the external terminal 60 has a pin portion 61 and a leg portion 62.

[0028] The pin portion 61 is a rod-shaped portion of the external terminal 60 that is inserted into the terminal hole 51. The pin portion 61 extends in the direction along the Z-axis within the terminal hole 51. 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 portion that protrudes from the outer wall surface of the case 50. This portion is connected to a board (not shown) on which the semiconductor module 10 is mounted. Meanwhile, the end of the pin portion 61 in the Z2 direction is connected to the leg portion 62. Note that the shape of the pin portion 61 is not limited to the example shown in FIG. 1 , and for example, the tip of the pin portion 61 may be shaped so as to branch into two parts.

[0029] The leg portion 62 is a plate-like portion of the external terminal 60 that is arranged along the surface of the spacer 70 facing the Z1 direction. The leg portion 62 extends from the end of the pin portion 61 in the Z2 direction toward the inside of the case 50. The leg portion 62 has a portion that is sandwiched between the case 50 and the spacer 70 and a portion that is exposed inside the case 50. One end of a wire, such as a bonding wire (not shown), is joined to the exposed portion. The other end of the wire is connected to the wiring board 20 or the semiconductor element 30. This connection electrically connects the external terminal 60 and the semiconductor element 30 to each other.

[0030] The spacer 70 is a frame-shaped member interposed between the base 40 and the case 50. The spacer 70 has the function of pressing the plurality of external terminals 60 toward the case 50 and the function of ensuring electrical insulation between each of the plurality of external terminals 60 and the base 40. The spacer 70 is essentially an insulator, and can be, for example, Case 50 Similarly, the spacer 70 is made of a resin material such as PPS (Polyphenylene Sulfide) or PBT (Polybutylene Terephthalate). The resin material may contain an inorganic filler such as alumina or silica in order to improve the mechanical strength of the spacer 70. The material making up the spacer 70 is not limited to a resin material, and may be, for example, a ceramic material.

[0031] 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 has a bonding surface 70a. The bonding surface 70a is bonded to the case 50 with an adhesive. Although not shown in FIG. 1 , the adhesive is adhesive B1, which will be described later. On the other hand, the surface of the spacer 70 facing the Z2 direction has a bonding surface 70b. The bonding surface 70b is bonded to the base 40, which is part of the laminate 11, with an adhesive. Although not shown in FIG. 1 , the adhesive is adhesive B2, which will be described later. Note that the bonding between the laminate 11 and the spacer 70 is not limited to bonding with an adhesive and may be, for example, bonded by screws. Furthermore, when the wiring board 20 is disposed over the entire area of ​​the base 40 or when the base 40 is omitted, the bonding surface 70b of the spacer 70 may be bonded to the wiring board 20 with an adhesive.

[0032] 1, a plurality of protrusions 71 are provided on the outer peripheral surface of the spacer 70, aligned in the circumferential direction. This makes it easier to insert the spacer 70 into the case 50, while allowing the case 50 and the spacer 70 to fit together. The number, positions, and shapes of the protrusions 71 are not limited to those in the example shown in FIG. 1, and are arbitrary. Each of the plurality of protrusions 71 may be provided as needed, or may be omitted.

[0033] The lid 80 is a plate-like member that is bonded to the surface of the case 50 facing the Z1 direction. The lid 80 is made of a resin material such as PPS (Polyphenylene Sulfide) or PBT (Polybutylene Terephthalate), similar to the case 50. 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.

[0034] Here, the space surrounded by the base 40, the case 50, and the lid 80 is filled with a potting material that covers the semiconductor element 30. Although not shown in Fig. 1, this potting material is the potting material PA described below. The potting material is made of, for example, a silicone resin such as silicone gel.

[0035] In the semiconductor module 10 outlined above, each of the multiple terminal holes 51 is sealed by the adhesive that bonds the case 50 and the spacer 70 together. Therefore, even when the semiconductor module 10 is used in a corrosive gas atmosphere, it is possible to reduce the intrusion of corrosive gas into the case 50 through the terminal holes 51. Here, the semiconductor module 10 has a configuration that increases the reliability of sealing each of the terminal holes 51 with the adhesive when bonding the case 50 and the spacer 70 together with the adhesive. This configuration will be described in detail below.

[0036] 1-2.Terminal hole FIG. 2 is a bottom view of the case 50, i.e., a view of the case 50 in the Z1 direction with multiple external terminals 60 attached. FIG. 3 is a perspective view showing a portion of the case 50. In FIG. 3, for the convenience of explaining the partition walls 55, the case 50 is shown viewed from a direction slightly tilted with respect to the Z1 direction. As shown in FIGS. 2 and 3, multiple partition walls 55 are provided in the case 50. Each partition wall 55 separates two adjacent terminal holes 51.

[0037] 2 and 3, each terminal hole 51 has a shape corresponding to the shape of the pin portion 61 of the external terminal 60. Specifically, each terminal hole 51 has a first portion 51a and a second portion 51b. The first portion 51a opens on the surface of the case 50 facing the Z1 direction. The second portion 51b is located further in the Z2 direction than the first portion 51a and opens on the surface of the case 50 facing the Z2 direction.

[0038] Here, the surface of the case 50 facing the Z2 direction has a plurality of joining surfaces 50a and a plurality of recesses 56.

[0039] Each bonding surface 50a is a surface of the case 50 facing the Z2 direction that is bonded to the bonding surface 70a of the spacer 70 with adhesive B1. That is, among the surfaces of the case 50 facing the Z2 direction, the bonding surface 50a is the surface closest to the bonding surface 70a of the spacer 70, and faces the bonding surface 70a via adhesive B1. In the example shown in FIG. 2, each bonding surface 50a is T-shaped in plan view. Note that the shape of the bonding surface 50a in plan view is not limited to the example shown in FIG. 2 and may be any shape.

[0040] Each recess 56 is recessed relative to the joining surface 50a and is located between two adjacent joining surfaces 50a in plan view. For each terminal hole 51, the recess 56 extends from the terminal hole 51 toward the inside of the case 50, connecting the inside of the case 50 with the terminal hole 51. When an external terminal 60 is inserted into the terminal hole 51 corresponding to the recess 56, a part of the leg 62 of the external terminal 60 is positioned in the recess 56. The recess 56 is shaped to fit into the part in plan view, and restricts the external terminal 60 from changing its position.

[0041] 3, the end of the partition wall 55 in the Z2 direction is located further in the Z1 direction than the bottom surface of the recessed portion 56. That is, the distance d along the Z axis between the end of the partition wall 55 in the Z2 direction and the bonding surface 50a is greater than the depth of the recessed portion 56. Here, the depth of the recessed portion 56 is approximately the same as the thickness of the leg portion 62 of the external terminal 60.

[0042] Fig. 4 is a cross-sectional view of the semiconductor module 10 taken along line AA in Fig. 2. Fig. 5 is a cross-sectional view of the semiconductor module 10 taken along line BB in Fig. 2. As shown in Figs. 4 and 5, a spacer 70 is interposed between the base 40 and the case 50.

[0043] The case 50 and the plurality of external terminals 60 are bonded to the bonding surface 70a of the spacer 70 with an adhesive B1. The base 40 is bonded to the bonding surface 70b of the spacer 70 with an adhesive B2.

[0044] Here, the adhesive B1 not only bonds the case 50 and the spacer 70 to each other but also seals each terminal hole 51. Therefore, compared to a configuration in which the terminal holes 51 are not sealed with the adhesive B1, the intrusion of corrosive gas into the case 50 through the terminal holes 51 can be reduced. Specifically, as shown in FIG. 5 , in terminal holes 51 into which no external terminals 60 are inserted, the adhesive B1 penetrates to a position in the Z1 direction beyond the Z2-direction end of the terminal hole 51, thereby sealing the terminal hole 51. Furthermore, although not shown, in terminal holes 51 into which external terminals 60 are inserted, the adhesive B1 fills the gap between the inner wall surface of the terminal hole 51 and the outer wall surface of the external terminal 60, thereby sealing the terminal hole 51.

[0045] The adhesive B1 is an insulating adhesive, and more specifically, the adhesive B1 is, for example, an epoxy adhesive, an acrylic adhesive, a urethane adhesive, or a silicone adhesive.

[0046] The adhesive B2 is not particularly limited, but may be, for example, an epoxy adhesive, an acrylic adhesive, a urethane adhesive, or a silicone adhesive. The adhesives B1 and B2 may be the same or different. In the example shown in FIG. 4, the adhesives B1 and B2 are separated from each other by a spacer 70, but this is not limited to this and they may be integrated. In addition, the adhesives B1 and B2 are not limited to thermosetting adhesives, but may be, for example, photosetting adhesives.

[0047] Here, the adhesive B1 is preferably a thermosetting adhesive. A thermosetting adhesive has the property of temporarily softening when heated before hardening. Therefore, using a thermosetting adhesive as the adhesive B1 has the advantage that the adhesive B1 before hardening can be easily guided to each terminal hole 51. Furthermore, a thermosetting adhesive can be hardened at the desired timing. Therefore, using a thermosetting adhesive as the adhesive B1 can also prevent the adhesive B1 from spreading more than necessary.

[0048] Furthermore, the gas barrier property of the adhesive B1 is preferably higher than that of the potting material PA. In this case, even if the semiconductor module 10 is used in a corrosive gas atmosphere, the intrusion of corrosive gas into the case 50 through the terminal holes 51 can be reduced compared to a configuration in which the terminal holes 51 are sealed with the potting material PA. The "gas barrier property" is measured, for example, by a method in accordance with ISO 15106. Furthermore, the adhesive B1 may contain an insulating inorganic filler such as alumina or silica to enhance the gas barrier property.

[0049] 4, the external terminal 60 to be inserted into the terminal hole 51 has a bonding surface 60a, which is an example of a "first bonding surface." The bonding surface 60a is bonded to the bonding surface 70a of the spacer 70 by adhesive B1. In the example shown in FIG. 4, the bonding surface 60a is the surface of the leg portion 62 of the external terminal 60 facing the Z2 direction.

[0050] Position P1 of the end of the partition wall 55 in the Z2 direction is located further in the Z1 direction than position P2 of the bonding surface 60a of the external terminal 60 in the Z2 direction. The distance between positions P1 and P2 in the direction along the Z axis is defined as distance L. The distance L between the bonding surface 60a and the partition wall 55 is greater than the thickness t of the external terminal 60. Therefore, a gap G1 having a size corresponding to distance L is provided between the partition wall 55 and the spacer 70.

[0051] The size of the gap G1 between the partition wall 55 of a terminal hole 51 into which an external terminal 60 is not inserted is equal to or larger than the size of the gap G1 between the partition wall 55 of a terminal hole 51 into which an external terminal 60 is inserted. That is, the distance between the partition wall 55 of a terminal hole 51 into which an external terminal 60 is not inserted and the spacer 70 is equal to or larger than the distance between the partition wall 55 of a terminal hole 51 into which an external terminal 60 is inserted and the spacer 70. Therefore, the gap G1 connects two adjacent terminal holes 51 regardless of whether an external terminal 60 is inserted in one or both of the adjacent terminal holes 51. Therefore, regardless of whether an external terminal 60 is inserted in one or both of the adjacent terminal holes 51, the uncured adhesive B1 can flow from one of the adjacent terminal holes 51 to the other through the gap G1. In particular, because a thermosetting adhesive has the property of temporarily softening when heated before curing, using a thermosetting adhesive as the adhesive B1 allows the uncured adhesive B1 to flow from one of the adjacent terminal holes 51 to the other through the gap G1. The term "equal" includes not only the case where they are strictly equal, but also the case where they can be considered to be substantially equal due to differences such as manufacturing errors.

[0052] Here, the thickness t is the thickness of the leg portion 62 of the external terminal 60. The specific thickness t is not particularly limited, but is, for example, about 1 mm.

[0053] It is preferable that the gap G2 between the inner peripheral surface of the case 50 and the outer peripheral surface of the spacer 70 be as small as possible. The smaller the gap G2, the more likely it is that the uncured adhesive B1 will escape along the inner peripheral surface of the case 50 toward the laminate 11. As a result, it is possible to reduce the occurrence of an insufficient amount of adhesive B1 between the external terminals 60 and the spacer 70 or an increase in the defect rate in processes after bonding using adhesive B1 due to the occurrence of air bubbles in the adhesive B1.

[0054] Here, the distance L is shorter than half the length LH of the terminal hole 51. This allows the adhesive B1 to flow smoothly from one of two adjacent terminal holes 51 to the other via the partition wall 55. The length LH of the terminal hole 51 is the distance between one opening edge and the other opening edge of the terminal hole 51 in the direction along the central axis LC.

[0055] The distance d, i.e., the difference (Lt) between the distance L and the thickness t, preferably satisfies the relationship 0.5 mm≦(Lt)≦2.0 mm. In this case, the uncured adhesive B1 can flow smoothly from one of the two adjacent terminal holes 51 to the other through the gap G1. On the other hand, if the difference (Lt) is too small, depending on the viscosity of the uncured adhesive B1, the uncured adhesive B1 tends to have difficulty flowing from one of the two adjacent terminal holes 51 to the other through the gap G1. On the other hand, if the difference (Lt) is too large, an excessive amount of adhesive B1 is placed in the gap G1. Depending on the amount of adhesive B1 applied, the uncured adhesive B1 may have difficulty flowing from one of the two adjacent terminal holes 51 to the other through the gap G1. Furthermore, if the difference (Lt) is too large, it becomes difficult to ensure the necessary mechanical strength of the case 50 while miniaturizing the case 50.

[0056] Here, since the depth of the recess 56 is approximately the same as the thickness t of the external terminal 60, the bonding surface 60a is located roughly on the same plane as the bonding surface 50a. Therefore, it can also be said that the distance L is the distance between the bonding surface 50a and the partition wall 55.

[0057] 6 is a cross-sectional view of the semiconductor module 10 taken along line CC in FIG. 2. In FIG. 6, terminal holes 51_1 to 51_3 are shown as three terminal holes 51. Terminal holes 51_1, 51_2, and 51_3 are arranged in this order. Here, terminal hole 51_1 and terminal hole 51_2 are two terminal holes 51 adjacent to each other. Similarly, terminal hole 51_2 and terminal hole 51_3 are two terminal holes 51 adjacent to each other.

[0058] The terminal hole 51_1 is a terminal hole 51 into which an external terminal 60 is inserted. On the other hand, the terminal holes 51_2 and 51_3 are terminal holes 51 into which no external terminal 60 is inserted.

[0059] 6, the pin portion 61 of the external terminal 60 has a first portion 61a and a second portion 61b. The first portion 61a is inserted into the first portion 51a of the terminal hole 51 and has a portion that protrudes from the outer wall surface of the case 50. The second portion 61b is inserted into the second portion 51b of the terminal hole 51, is positioned further in the Z2 direction than the first portion 61a, and is connected to the leg portion 62. The width of the second portion 61b along the circumferential direction of the case 50 is greater than the width of the first portion 61a along the circumferential direction of the case 50. In this way, the pin portion 61 has a shape that corresponds to the shape of the terminal hole 51.

[0060] As shown in FIG. 6, each of the terminal holes 51_1 to 51_3 is sealed with an adhesive B1.

[0061] More specifically, the terminal hole 51_1 is sealed by disposing the adhesive B1 so as to fill the gap between the wall surface of the terminal hole 51_1 and the external terminal 60. Here, as described above, the distance L is greater than the thickness t, so that the adhesive B1 before hardening easily enters the gap. This increases the reliability of sealing the terminal hole 51_1 with the adhesive B1.

[0062] Furthermore, the adhesive B1 enters each of terminal holes 51_2 and 51_3 in the Z1 direction from the Z2-direction end of partition wall 55, thereby sealing each of terminal holes 51_2 and 51_3. Here, as described above, because distance L is greater than thickness t, even if there is variation in the amount of adhesive B1 applied before hardening between application positions, the adhesive B1 before hardening flows from one of terminal holes 51_2 and 51_3 to the other so as to reduce such variation. This increases the reliability of sealing of terminal holes 51_2 and 51_3 with adhesive B1.

[0063] 1-3. Manufacturing method of semiconductor module 7 is a flowchart showing a method for manufacturing a semiconductor module 10 according to the first embodiment. As shown in FIG. 7, the method for manufacturing a semiconductor module 10 includes, in this order, a preparation step S10, a terminal insertion step S20, and a bonding step S30. Here, the bonding step S30 includes, in this order, an application step S31, a bonding step S32, a softening step S33, and a hardening step S34. Each step will be described below in order. Note that the following description will be given taking, as an example, a case where the aforementioned adhesive B1 is a thermosetting adhesive.

[0064] 1-3-1. Preparation process Fig. 8 is a diagram for explaining the preparation step S10. Fig. 8 shows a view of a part of the case 50 as viewed in the Z1 direction. In the preparation step S10, the case 50 is prepared as shown in Fig. 8. The case 50 is formed by, for example, injection molding.

[0065] Although not shown, in the preparation step S10, in addition to the case 50, a plurality of external terminals 60 and spacers 70 are also prepared. The external terminals 60 are formed, for example, by pressing and bending a metal plate. The spacers 70 are formed, for example, by injection molding.

[0066] 1-3-2. Terminal insertion process 9 is a diagram illustrating the terminal insertion step S20. FIG. 9 shows a view of a portion of the case 50 as viewed in the Z1 direction. In the terminal insertion step S20, as shown in FIG. 9, external terminals 60 are inserted into two or more predetermined terminal holes 51 among the plurality of terminal holes 51 of the case 50. More specifically, the leg portions 62 of the external terminals 60 are placed in the recesses 56, and the pin portions 61 of the external terminals 60 are inserted into the terminal holes 51. At this time, the pin portions 61 may fit into the terminal holes 51, or the leg portions 62 may fit into the recesses 56.

[0067] 1-3-3.Joining process In the joining step S30, the application step S31, the bonding step S32, the softening step S33, and the hardening step S34 are carried out in this order, so that the case 50 and the spacer 70 are joined together with the adhesive B1.

[0068] 1-3-3a.Coating process FIG. 10 is a diagram illustrating the application step S31 in the joining step S30. FIG. 10 shows a view of a portion of the case 50 viewed in the Z1 direction. In the application step S31, as shown in FIG. 10, an uncured adhesive B1a is applied to the surface of the case 50 facing the Z2 direction. More specifically, with the Z2 direction facing upward in the vertical direction, the uncured adhesive B1a is applied along the entire circumferential direction of the case 50 to the surface of the case 50 facing the Z2 direction after the terminal insertion step S20. Here, the adhesive B1a is applied to both the joining surface 50a of the case 50 and the joining surface 60a of the external terminal 60. The application is performed using, for example, a dispenser.

[0069] In the application step S31, the adhesive B1a may be applied to the joining surface 70a of the spacer 70. In this case, application of the adhesive B1a to the joining surface 50a of the case 50 may be omitted in the application step S31. Furthermore, the area to which the adhesive B1a is applied in the application step S31 may be extended over the entire periphery of the case 50 or the spacer 70 in the bonding step S32 described below, and the adhesive B1a may be partially missing in the circumferential direction of the case 50 or the spacer 70.

[0070] 1-3-3b. Bonding process FIG. 11 is a diagram illustrating the bonding step S32 in the joining step S30. In FIG. 11, a structure in which the case 50 and the spacer 70 are bonded together via the adhesive B1a is shown in cross section corresponding to the aforementioned FIG. 4. In the bonding step S32, after the application step S31, the case 50 and the spacer 70 are bonded together via the adhesive B1a, as shown in FIG. 11. Here, the spacer 70 is inserted inside the case 50 so that the bonding surface 50a of the case 50 and the bonding surface 70a of the spacer 70 face each other. Then, the spacer 70 is pressed against the case 50, causing the adhesive B1a to spread.

[0071] In the bonding process S32, the thickness of the adhesive B1a may vary between application positions depending on the viscosity or temperature of the adhesive B1a. In the example shown in FIG. 11, the thickness of the adhesive B1a at the terminal hole 51_2 is thicker than the thickness of the adhesive B1a at the terminal hole 51_3. As described above, since the position P1 of the partition wall 55 is located in the Z1 direction from the joining surface 50a of the case 50, the adhesive B1a is likely to move between the terminal holes 51_2 and 51_3. In particular, since the position P1 of the partition wall 55 is located in the Z1 direction from the joining surface 60a of the external terminal 60, the adhesive B1a is also likely to move between the terminal holes 51_1 and 51_2. Therefore, the variation in the thickness of the adhesive B1a is reduced compared to the conventional configuration in which the position P1 is on the same plane as the joining surface 60a.

[0072] 1-3-3c. Softening process FIG. 12 is a diagram illustrating the softening step S33 in the bonding step S30. In FIG. 12, a structure in which the case 50 and the spacer 70 are bonded together via the adhesive B1a is shown in a cross section corresponding to the aforementioned FIG. 4. In the softening step S33, the adhesive B1a is softened, thereby further reducing variations in the thickness of the adhesive B1a, as shown in FIG. 12. At this time, the adhesive B1a is softened by heating it at a temperature lower than the curing temperature using a heater, oven, or the like. The processing temperature and processing time of the softening step S33 are determined depending on the type of adhesive B1a, etc., and are not particularly limited and can be determined as desired.

[0073] 1-3-3d.Curing process In the curing step S34, after the softening step S33, the adhesive B1a is further heated to harden the adhesive B1a. As a result, the adhesive B1 is formed as a cured product of the adhesive B1a. The curing step S34 may be performed after a time interval following the softening step S33, or may be performed consecutively immediately after the softening step S33. Here, when the curing step S34 is performed consecutively immediately after the softening step S33, the softening step S33 may be considered to be part of the curing step S34. In other words, the softening step S33 may be performed so as to overlap part of the curing step S34.

[0074] Although not shown, after the curing step S34, the laminate 11 is bonded to the spacer 70 with adhesive B2. Thereafter, wires W are formed by wire bonding or the like, thereby electrically connecting the external terminals 60 and the semiconductor element 30. Then, after the potting material PA is filled into the case 50, the lid 80 is bonded to the case 50 with adhesive or the like. In this manner, the semiconductor module 10 is manufactured.

[0075] As described above, the method for manufacturing the semiconductor module 10 includes the preparation step S10, the terminal insertion step S20, and the bonding step S30. The preparation step S10 prepares the case 50 having a plurality of terminal holes 51. The terminal insertion step S20 inserts a plurality of external terminals 60 into two or more of the plurality of terminal holes 51. The bonding step S30 bonds the case 50 and the spacer 70 to each other with the adhesive B1.

[0076] Here, each of the plurality of external terminals 60 has a bonding surface 60a, which is an example of a "first bonding surface." The bonding surface 60a is bonded to the spacer 70 with an adhesive B1. The case 50 also has a partition wall 55 provided between two adjacent terminal holes 51 among the plurality of terminal holes 51. Furthermore, the distance L between the bonding surface 60a and the partition wall 55 is greater than the thickness t of each of the plurality of external terminals 60. Then, in the bonding process S30, each of the plurality of terminal holes 51 is sealed with the adhesive B1.

[0077] As described above, the semiconductor module 10 includes the semiconductor element 30, the laminate 11, the case 50, a plurality of external terminals 60, and the spacer 70. The laminate 11 includes the wiring board 20 on which the semiconductor element 30 is mounted. The case 50 has a plurality of terminal holes 51 and houses the semiconductor element 30. The plurality of external terminals 60 are inserted into two or more of the plurality of terminal holes 51 and are electrically connected to the semiconductor element 30. The spacer 70 is interposed between the laminate 11 and the case 50. The case 50, the plurality of external terminals 60, and the spacer 70 form a case unit 12.

[0078] As described above, the case 50 and the spacer 70 are bonded to each other with the adhesive B1. Each of the multiple external terminals 60 has a bonding surface 60a, which is an example of a "first bonding surface." The bonding surface 60a is bonded to the spacer 70 with the adhesive B1. The case 50 also has a partition wall 55 provided between two adjacent terminal holes 51 among the multiple terminal holes 51. The distance L between the partition wall 55 of the two or more terminal holes 51 and the bonding surface 60a is greater than the thickness t of each of the multiple external terminals 60. The distance (the size of the gap G1) between the partition wall 55 of the terminal holes 51 other than the two or more terminal holes 51 among the multiple terminal holes 51 and the spacer 70 is equal to or greater than the distance (the size of the gap G1) between the partition wall 55 of the two or more terminal holes 51 and the spacer 70.

[0079] In the semiconductor module 10 described above, the distance L is greater than the thickness t, and the size of the gap G1 between the partition wall 55 of the terminal hole 51 into which the external terminal 60 is not inserted is equal to or greater than the size of the gap G1 between the partition wall 55 of the terminal hole 51 into which the external terminal 60 is inserted. Therefore, regardless of whether an external terminal 60 is inserted into one or both of two adjacent terminal holes 51, the gap G1 that connects the two terminal holes 51 can be formed between the partition wall 55 and the spacer 70. Therefore, when the spacer 70 and the case 50 are joined to each other with the adhesive B1, the uncured adhesive B1 can flow from one of the two terminal holes 51 to the other through the gap G1. Therefore, even if the amount of adhesive B1 applied to the spacer 70 or the case 50 varies depending on the application position, each of the two terminal holes 51 can be sealed with the adhesive B1. This allows all of the terminal holes 51 in the case 50 to be sealed with the adhesive B1 with high reliability. As a result, even if the semiconductor module 10 is used in a corrosive gas atmosphere, it is possible to reduce the intrusion of the corrosive gas into the case 50 through the terminal holes 51. As can be understood from the above, the semiconductor module 10 can reduce damage even when used in a corrosive gas atmosphere.

[0080] As described above, the case 50 is filled with the potting material PA that covers the semiconductor element 30. Since the gas barrier property of the adhesive B1 is higher than the gas barrier property of the potting material PA, even when the semiconductor module 10 is used in a corrosive gas atmosphere, the intrusion of corrosive gas into the case 50 through the terminal holes 51 can be reduced compared to a configuration in which the terminal holes 51 are sealed with the potting material PA.

[0081] Furthermore, as described above, each of the case 50 and the spacer 70 is frame-shaped. The multiple terminal holes 51 are arranged along the circumferential direction of the case 50. Furthermore, the gap G2 between the inner circumferential surface of the case 50 and the outer circumferential surface of the spacer 70 is smaller than the gap G1 between the spacer 70 and the partition wall 55. Therefore, when the spacer 70 and the case 50 are joined with the adhesive B1, the adhesive B1 is prevented from escaping along the inner circumferential surface of the case 50 toward the laminate 11. As a result, by pressing the spacer 70 toward the case 50, the adhesive B1 can be suitably spread along the circumferential direction of the spacer 70.

[0082] As described above, the partition wall 55 is formed such that the centers P in the longitudinal direction of the two terminal holes 51 adjacent to each other with the partition wall 55 interposed therebetween are aligned. 0 The gap G1 is closer to the spacer 70 than the gap G2. This allows the adhesive B1 to flow smoothly from one of the two adjacent terminal holes 51 to the other. In particular, as described above, when the distance between the partition wall 55 and the bonding surface 60a is L [mm] and the thickness of each of the multiple external terminals 60 is t [mm], by satisfying the relationship 0.5≦(Lt)≦2.0, the adhesive B1 can flow smoothly from one of the two adjacent terminal holes 51 to the other through the gap G1.

[0083] Furthermore, as described above, each of the multiple external terminals 60 has a pin portion 61 and a leg portion 62. The pin portion 61 extends along one of the two or more terminal holes 51. The leg portion 62 is disposed between the case 50 and the spacer 70 and is connected to the pin portion 61. The leg portion 62 has a joint surface 60a. Therefore, by interposing the leg portion 62 between the case 50 and the spacer 70, the external terminal 60 can be stably supported by the case 50 and the spacer 70. In addition, a portion of the leg portion 62 can be exposed inside the case 50. As a result, electrical connection between the external terminal 60 and the semiconductor element 30 can be easily achieved.

[0084] Furthermore, as described above, because the adhesive B1 is a thermosetting adhesive, the adhesive B1 before hardening can be suitably flowed from one of the two adjacent terminal holes 51 to the other through the gap G1. This also makes it possible to prevent the adhesive B1 from spreading more than necessary.

[0085] 2. Second embodiment A second embodiment of the present disclosure will be described below. In the following exemplary embodiment, for elements whose actions and functions are similar to those of the above-described embodiment, the reference numerals used in the description of the above-described embodiment will be used, and detailed descriptions of each element will be omitted as appropriate.

[0086] 13 is an exploded perspective view of a semiconductor module 10A according to the second embodiment. The semiconductor module 10A has the same configuration as the semiconductor module 10 of the first embodiment described above, except that it includes a spacer 70A instead of the spacer 70. Here, the case 50, the plurality of external terminals 60, and the spacer 70A constitute a case unit 12A.

[0087] The spacer 70A is configured similarly to the spacer 70, except that it has a recess 72. The recess 72 is a groove provided over the entire circumferential direction on the joining surface 70a of the spacer 70A. In the example shown in FIG. 13, the width of the recess 72 is constant. Furthermore, the recess 72 has a shape that extends along each side of the spacer 70.

[0088] 13, the shape of the recess 72 may be, for example, a shape having a plurality of portions with different widths or a shape having a meandering portion. The recess 72 may have a missing portion in a portion in the circumferential direction of the spacer 70A, and may be provided intermittently along the circumferential direction of the spacer 70A, for example.

[0089] 14 is a cross-sectional view of a semiconductor module 10A according to the second embodiment. In FIG. 14, the semiconductor module 10A is shown in a cross section corresponding to the above-mentioned FIG. 4. As shown in FIG. 14, at least a part of the recess 72 is in The recesses 72 overlap the joining surface 60a. This allows the adhesive B1 to spread before hardening along the joining surface 60a. Furthermore, at least a portion of the recesses 72 overlaps the terminal holes 51 in a plan view. This allows the adhesive B1 before hardening to flow from one of the two adjacent terminal holes 51 to the other.

[0090] In the example shown in Fig. 14, the cross-sectional shape of the recess 72 is V-shaped. Note that the cross-sectional shape of the recess 72 is not limited to that shown in Fig. 14 and may be, for example, U-shaped or rectangular. Furthermore, the number of recesses 72 is not limited to one and may be two or more.

[0091] According to the second embodiment described above, all of the terminal holes 51 in the case 50 can be sealed with high reliability using the adhesive B1. As a result, damage to the semiconductor module 10A can be reduced even when used in a corrosive gas atmosphere. In this embodiment, as described above, the spacer 70 has a bonding surface 70a, which is an example of a "second bonding surface." The bonding surface 70a is bonded to each of the multiple external terminals 60 with the adhesive B1. In addition, the bonding surface 70a has a recess 72 extending in the direction in which the multiple terminal holes 51 are arranged. This allows the uncured adhesive B1 to flow efficiently from one of two adjacent terminal holes 51 to the other through the recess 72.

[0092] 3. 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.

[0093] 3-1. Variation 1 In each of the above-described embodiments, an example is given in which the application step S31 is performed before the bonding step S32, but the present invention is not limited to this example, and the application step S31 may be performed after the bonding step S32. For example, if the adhesive B2 also serves as the adhesive B1, when the base 40 and the spacer 70 are joined to each other with the adhesive B2, the adhesive B2 before hardening may find its way between the case 50 and the spacer 70 through a gap between the outer peripheral surface of the spacer 70 and the inner peripheral surface of the case 50. [Explanation of symbols]

[0094] 10...semiconductor module, 10A...semiconductor module, 11...laminated plate, 12...case unit, 12A...case unit, 20...wiring board, 30...semiconductor element, 40...base, 41...mounting hole, 50...case, 50a...bonding surface, 51...terminal hole, 51_1...terminal hole, 51_2...terminal hole, 51_3...terminal hole, 51a...first portion, 51b...second portion, 55...partition wall, 56...recess, 60...external terminal, 60a...bonding surface (first bonding surface), 61...pin portion, 61a...first portion, 61b...second portion, 62...leg portion, 70 ...spacer, 70A...spacer, 70a...joining surface (second joining surface), 70b...joining surface, 71...protrusion, 72...recess, 80...lid, B1...adhesive, B1a...adhesive, B2...adhesive, G1...gap, G2...gap, L...distance, LC...center axis, P...center, P0...center, P1...position, P2...position, PA...potting material, S10...preparation process, S20...terminal insertion process, S30...joining process, S31...application process, S32...bonding process, S33...softening process, S34...hardening process, W...wire, d...distance, t...thickness.

Claims

1. A semiconductor element; a laminate including a wiring substrate on which the semiconductor element is mounted; a case having a plurality of terminal holes and accommodating the semiconductor element; a plurality of external terminals that are inserted into two or more of the plurality of terminal holes and electrically connected to the semiconductor element; a spacer interposed between the laminate and the case, the case and the spacer are joined together with an adhesive; each of the plurality of external terminals has a first bonding surface bonded to the spacer by the adhesive; the case has a partition wall provided between two adjacent terminal holes among the plurality of terminal holes, a distance between the partition wall and the first bonding surface of the two or more terminal holes is greater than a thickness of each of the plurality of external terminals; a distance between the partition wall and the spacer of each of the plurality of terminal holes other than the two or more terminal holes is equal to or greater than a distance between the partition wall and the spacer of each of the two or more terminal holes; Semiconductor module.

2. Each of the plurality of terminal holes is sealed with the adhesive. The semiconductor module according to claim 1 .

3. The case is filled with a potting material that covers the semiconductor element, The gas barrier property of the adhesive is higher than the gas barrier property of the potting material.

3. The semiconductor module according to claim 1.

4. the spacer has a second bonding surface bonded to each of the plurality of external terminals with the adhesive; The second bonding surface is provided with a recess extending along the direction in which the plurality of terminal holes are arranged. The semiconductor module according to claim 1 .

5. the partition wall is closer to the spacer than the centers of the two terminal holes in the longitudinal direction; The semiconductor module according to claim 1 .

6. When the distance between the partition wall and the first bonding surface is L [mm] and the thickness of each of the plurality of external terminals is t [mm], The relationship 0.5≦(L−t)≦2.0 is satisfied. The semiconductor module according to claim 5 .

7. Each of the plurality of external terminals is a pin portion extending along any one of the two or more terminal holes; a leg portion disposed between the case and the spacer and connected to the pin portion; The leg portion has the first joint surface. The semiconductor module according to claim 1 .

8. The adhesive is a thermosetting adhesive. The semiconductor module according to claim 1 .

9. a preparation step of preparing a case having a plurality of terminal holes; a terminal insertion step of inserting a plurality of external terminals into two or more terminal holes among the plurality of terminal holes; a joining step of joining the case and the spacer together with an adhesive, each of the plurality of external terminals has a first bonding surface bonded to the spacer by the adhesive; the case has a partition wall provided between two adjacent terminal holes among the plurality of terminal holes, a distance between the first bonding surface and the partition wall is greater than a thickness of each of the plurality of external terminals; In the joining step, each of the plurality of terminal holes is sealed with the adhesive. A method for manufacturing a semiconductor module.

10. a case having a plurality of terminal holes; a plurality of external terminals to be inserted into two or more of the plurality of terminal holes; a spacer bonded to the case with an adhesive; each of the plurality of external terminals has a first bonding surface bonded to the spacer by the adhesive; the case has a partition wall provided between two adjacent terminal holes among the plurality of terminal holes, a distance between the first bonding surface and the partition wall is greater than a thickness of each of the plurality of external terminals; Each of the plurality of terminal holes is sealed with the adhesive. Case unit.

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