Semiconductor module

Abstract

To provide a semiconductor module in which the attachment allowance between a case part and a base part can be reduced.SOLUTION: A semiconductor module 1 includes a base part 13 including a plurality of semiconductor elements Su1 to Sw2 and a cooler 131 for cooling the semiconductor elements Su1 to Sw2, a case part 11 that is attached to the base part 13 and defines a space 12 where the semiconductor elements Su1 to Sw2 are disposed, a first protrusion part 117 that has a shape whose size in a first direction L1 passing a center 117a thereof and size in a second direction L2 intersecting with the first direction L1 and passing the center 117a are different and protrudes from the case part 11 toward the side where the base part 13 is disposed, and a penetration hole 137 larger than the outer periphery of the first protrusion part 117, having an opening along the shape of the outer periphery of the first protrusion part 117, formed penetrating the base part 13, and having the first protrusion part 117 inserted therein.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a semiconductor module applied to a power conversion device or the like.

Background Art

[0002] Patent Document 1 discloses a precision substrate storage container in which a lid is fitted into one end face of an opening of a container body for storing a precision substrate and closed in a sealed state. In the precision substrate storage container, a pair of positioning recesses are provided on the surface of the lid at intervals, and at least one of the pair of positioning recesses is formed in an elongated hole having a long axis on a line connecting the pair of positioning recesses.

[0003] Patent Document 2 discloses a semiconductor module having a configuration in which adjustment pins aligned vertically are formed in a case, and the position of a sub-assembly component is determined by the upper adjustment pins, and the position of another sub-assembly component is determined by the lower adjustment pins.

[0004] When assembling a semiconductor module such as an Insulated Gate Bipolar Transistor (IGBT), it is necessary to attach a plurality of assembly components (for example, a base part and a case part) to each other. When two or more sub-assemblies are attached to each other in a semiconductor module, the tolerances of the individual assemblies are added. As a result, there is a problem that it may be impossible to attach the sub-assembly further, or the attachment of the sub-assembly may become difficult.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] A common solution to the problem of added assembly tolerances is to reduce assembly tolerances by combining multiple assembly parts based on a fixture pin. However, in this method, the tolerance of each assembly part is calculated by adding the tolerance with the fixture pin to the assembly tolerance with other assembly parts. Therefore, conventional techniques have the problem that as the number of assembly parts increases, the tolerance of each assembly part becomes larger, and each assembly part may become larger.

[0007] Furthermore, if the tolerances of each assembly part are reduced to avoid increasing the size of each assembly part, it may be possible to position each assembly part relative to the jig pin, but this could lead to problems such as the assembly process becoming complicated or even impossible. This problem is more likely to occur when the assembly parts are manufactured by different companies.

[0008] The object of the present invention is to provide a semiconductor module that can reduce the mounting tolerance between the case portion and the base portion as an assembly component. [Means for solving the problem]

[0009] To achieve the above objective, a semiconductor module according to one aspect of the present invention comprises multiple semiconductors The device comprises a base portion having a cooler for cooling the element and the plurality of semiconductor elements; a case portion attached to the base portion and defining a space in which the plurality of semiconductor elements are arranged; a first projection having a shape in which the dimensions in a first direction passing through its own center and the dimensions in a second direction intersecting the first direction and passing through the center are different, and projecting from the case portion toward the side in which the base portion is arranged; and a through hole formed through the base portion, having an opening larger than the outer circumference of the first projection and conforming to the shape of the outer circumference of the first projection, into which the first projection is inserted. Furthermore, in order to achieve the above objective, a semiconductor module according to another aspect of the present invention includes a base portion having a plurality of semiconductor elements and a cooler for cooling the plurality of semiconductor elements; a case portion attached to the base portion and defining a space in which the plurality of semiconductor elements are arranged; a first projection having a shape in which the dimensions in a first direction passing through its own center and the dimensions in a second direction intersecting the first direction and passing through the center are different, and projecting from the case portion toward the side in which the base portion is arranged; and a portion larger than the outer circumference of the first projection and shaped in which the outer circumference of the first projection is The case portion has an opening along the base portion and a through hole formed through the base portion into which the first projection is inserted, and the case portion has a side wall facing the side surface of the base portion and a second projection projecting from the side wall of the case portion toward the side surface of the base portion, and the base portion and the case portion are rectangles having a pair of long sides and a pair of short sides in plan view, the first projection is located on one of the short sides, on the side farther from one of the long sides, and the second projection is located on the other short side and one of the long sides, respectively, sandwiching the corner between the other short side and one of the long sides. [Effects of the Invention]

[0010] This invention each Depending on the embodiment, the mounting tolerance between the case portion and the base portion can be reduced as an assembly part. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows an example of a schematic configuration of a semiconductor module according to one embodiment of the present invention, and is a plan view of the semiconductor module as seen from the case side. [Figure 2] This figure shows an example of a schematic configuration of a semiconductor module according to one embodiment of the present invention, and is a bottom view of the semiconductor module as seen from the base side. [Figure 3] This figure shows a magnified view of the vicinity of a first protrusion provided in a semiconductor module according to one embodiment of the present invention. [Figure 4] This figure shows an enlarged view of a second projection provided on a semiconductor module according to one embodiment of the present invention, and is a cross-sectional view obtained by cutting the semiconductor module along the α-α line shown in Figure 2. [Figure 5] This figure illustrates the effect of a semiconductor module according to one embodiment of the present invention, and shows an example of the assembly tolerances of a conventional semiconductor module. [Modes for carrying out the invention]

[0012] Each embodiment of the present invention illustrates an apparatus or method for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the materials, shapes, structures, arrangements, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims described in the patent claims.

[0013] (Overall configuration of the semiconductor module) A semiconductor module according to one embodiment of the present invention will be described with reference to Figures 1 to 5. First, the schematic configuration of the semiconductor module according to this embodiment will be described with reference to Figures 1 to 4. In this embodiment, a power conversion module capable of DC to AC conversion will be used as an example of the semiconductor module. Note that the sealing resin provided in the semiconductor module is not shown in Figure 1.

[0014] As shown in Figures 1 and 2, the semiconductor module 1 according to this embodiment includes a base portion 13 (see Figure 2) having a plurality of (six in this embodiment) semiconductor elements Su1, Su2, Sv1, Sv2, Sw1, Sw2 (see Figure 1) and a cooler 131 (see Figure 2) for cooling the plurality of semiconductor elements Su1, Su2, Sv1, Sv2, Sw1, Sw2. Hereinafter, "Su1, Su2, Sv1, Sv2, Sw1, Sw2" may be abbreviated as "Su1~Sw2". Also, as shown in Figure 1, the semiconductor module 1 includes a case portion 11 attached to the base portion 13 (not shown in Figure 1) that defines a space 12 in which the plurality of semiconductor elements Su1~Sw2 are arranged. Details will be described later, but as shown in Figure 2, the semiconductor module 1 is Case section 11 It comprises a first projection 117 and a second projection 119a, 119b formed thereon, and a through hole 137 formed in the base portion 13 into which the first projection 117 is inserted.

[0015] Semiconductor elements Su1 and Su2 are switching elements that constitute the inverter circuit for the U phase. Semiconductor elements Sv1 and Sv2 are switching elements that constitute the inverter circuit for the V phase. Semiconductor elements Sw1 and Sw2 are switching elements that constitute the inverter circuit for the W phase.

[0016] As shown in FIG. 1, the case portion 11 has a peripheral portion 111 formed in a rectangular frame shape. As a result, the case portion 11 has a rectangular outer shape. That is, the case portion 11 has a rectangular outer shape when viewed in the axial direction of the substrate mounting holes 112 (details will be described later) (i.e., in a plan view). The case portion 11 has a partition portion 114a that partitions a part of the space 12 into a U-phase space 121u and a V-phase space 121v, and a partition portion 114b that partitions the remaining portion of the space 12 into a V-phase space 121v and a W-phase space 121w.

[0017] In the U-phase space 121u, a U-phase laminated substrate 14u provided with an inverter circuit for the U-phase, such as semiconductor elements Su1, Su2, etc., is arranged. In the V-phase space 121v, a V-phase laminated substrate 14v provided with an inverter circuit for the V-phase, such as semiconductor elements Sv1, Sv2, etc., is arranged. In the W-phase space 121w, a W-phase laminated substrate 14w provided with an inverter circuit for the W-phase, such as semiconductor elements Sw1, Sw2, etc., is arranged. The U-phase space 121u becomes a casting region where a sealing resin (not shown) for sealing the U-phase laminated substrate 14u is cast. The V-phase space 121v becomes a casting region where a sealing resin (not shown) for sealing the V-phase laminated substrate 14v is cast. The W-phase space 121w becomes a casting region where a sealing resin (not shown) for sealing the W-phase laminated substrate 14w is cast. As a result, the U-phase laminated substrate 14u, the V-phase laminated substrate 14v, and the W-phase laminated substrate 14w are each sealed with a sealing resin.

[0018] The peripheral portion 111 has, for example, a flat plate shape. The peripheral portion 111 has a pair of short side portions 111a and 111b arranged opposite to each other, and a pair of long side portions 111c and 111d stretched across both ends of the pair of short side portions 111a and 111b and arranged opposite to each other. In the corresponding region of the U-phase space 121u of the long side portion 111c, a positive electrode side terminal Pu and a negative electrode side terminal Nu to which DC power supplied to the semiconductor elements Su1 and Su2 is input are arranged. In the corresponding region of the V-phase space 121v of the long side portion 111c, a positive electrode side terminal Pv and a negative electrode side terminal Nv to which DC power supplied to the semiconductor elements Sv1 and Sv2 is input are arranged. In the corresponding position of the W-phase space 121w of the long side portion 111c, a positive electrode side terminal Pw and a negative electrode side terminal Nw to which DC power supplied to the semiconductor elements Sw1 and Sw2 is input are arranged.

[0019] In the corresponding region of the U-phase space 121u of the long side portion 111d, an output terminal Ou through which U-phase AC power generated by the U-phase inverter circuit is output is arranged. In the corresponding region of the V-phase space 121v of the long side portion 111d, an output terminal Ov through which V-phase AC power generated by the V-phase inverter circuit is output is arranged. In the corresponding region of the W-phase space 121w of the long side portion 111d, an output terminal Ow through which W-phase AC power generated by the W-phase inverter circuit is output is arranged.

[0020] The semiconductor module 1 has a columnar portion 115 protruding from the case portion 11. The columnar portion 115 is arranged on the short side portion 111a. The columnar portion 115 is arranged closer to the long side portion 111d. The columnar portion 115 is used as a reference position for attaching a circuit board (not shown) provided with a control circuit for controlling the semiconductor elements Su1 to Sw2 to the case portion 11. A plurality (eight in this embodiment) of board mounting holes 112 for attaching the circuit board to the case portion 11 and the base portion 13 are formed in the peripheral portion 111 of the case portion 11. The board mounting holes 112 are formed through the peripheral portion 111.

[0021] As shown in Figure 2, the case portion 11 has a side wall 113 facing the side surface 139 of the base portion 13. The side wall 113 is arranged to surround the base portion 13. The side wall 113 is formed integrally with the peripheral portion 111. The side wall 113 is formed from the outer end of the peripheral portion 111, almost perpendicular to the surface of the peripheral portion 111 (the surface on which output terminals Ou, Ov, Ow, etc. are arranged).

[0022] The side wall 113 of the case portion 11 has a pair of opposing short sides 113a, 113b and a pair of opposing long sides 113c, 113d that are stretched across both ends of the pair of short sides 113a, 113b. The case portion 11 has second projections 119a, 119b that protrude from the side wall 113 toward the side surface 139. The second projection 119a is formed on the short side 113b of the side wall 113. The second projection 119a is formed on the surface of the short side 113b facing the side surface 139 of the base portion 13. The second projection 119b is formed on the long side 113c of the side wall 113. The second projection 119b is formed on the surface of the long side 113c facing the side surface 139 of the base portion 13. The specific structure of the second projections 119a, 119b will be described later.

[0023] The peripheral portion 111, partition portions 114a, 114b, columnar portion 115, and side wall 113 that constitute the case portion 11 are formed integrally, for example. The case portion 11 is made of, for example, an insulating thermoplastic resin.

[0024] As shown in Figure 2, the base portion 13 has a rectangular shape. That is, the base portion 13 has a rectangular shape when viewed in the axial direction of the substrate mounting hole 132 (details will be described later) (i.e., in a plan view). The base portion 13 has a cooler 131 provided in the center and a peripheral portion 133 that is arranged around the cooler 131 and opposite the peripheral portion 111 of the case portion 11.

[0025] The cooler 131 has a rectangular shape in plan view. The cooler 131 has a storage space 131a (not shown in Figure 2, see Figure 4) capable of storing a coolant (water in this embodiment). The base portion 13 has inlet and outlet ports 135a and 135b located at two opposing corners of the four corners of the cooler 131. The inlet and outlet ports 135a and 135b have a cylindrical shape. The space inside the inlet and outlet ports 135a and 135b is in communication with the storage space 131a of the cooler 131. This allows, for example, the coolant to flow into the storage space 131a of the cooler 131 via the inlet and outlet port 135a, and for example, the coolant in the storage space 131a to flow out to the outside via the inlet and outlet port 135b.

[0026] On the surface of the cooler 131 on the side where the case portion 11 is placed, the U-phase laminated substrate 14u, the V-phase laminated substrate 14v, and the W-phase laminated substrate 14w (see Figure 1) are in contact with each other. The U-phase laminated substrate 14u, the V-phase laminated substrate 14v, and the W-phase laminated substrate 14w are fixed to the cooler 131 by soldering, for example, a heat transfer member (not shown) provided opposite the cooler 131. This prevents the semiconductor elements Su1~Sw2, the U-phase laminated substrate 14u, the V-phase laminated substrate 14v, and the W-phase laminated substrate 14w from exceeding their rated temperature due to the heat generated during the operation of the semiconductor elements Su1~Sw2.

[0027] The peripheral edge 133 of the base portion 13 has, for example, a flat plate shape. The peripheral edge 133 has a pair of short sides 133a, 133b arranged opposite each other, and a pair of long sides 133c, 133d stretched across both ends of the pair of short sides 133a, 133b and arranged opposite each other. The short side 133a of the base portion 13 is positioned opposite to and in contact with the short side 111a of the case portion 11. The short side 133b of the base portion 13 is positioned opposite to and in contact with the short side 111b of the case portion 11. The long side 133c of the base portion 13 is positioned opposite to and in contact with the long side 111c of the case portion 11. The long side 133d of the base portion 13 is positioned opposite to and in contact with the long side 111d of the case portion 11.

[0028] The base portion 13 has a side surface 139 facing the side wall 113 of the case portion 11. The side surface 139 is Base part 13 This is the surface of the side end. The side surface 139 is formed to be slightly smaller than the side wall 113 of the case portion 11 and is positioned along the side wall 113 on the inner circumference side of the side wall 113. The side surface 139 is positioned with a predetermined gap between it and the side wall 113 of the case portion 11. The second protrusions 119a and 119b are positioned in this gap. The side surface 139 is also the surface of the side end of the peripheral portion 133. A part of the side surface 139 is composed of the surface of the side end of the cooler 131.

[0029] The cooler 131 and peripheral portion 133 are formed of a material with high thermal conductivity (e.g., aluminum). The case portion 11 is fixed to the base portion 13, for example, by adhesive.

[0030] The peripheral edge 133 of the base portion 13 has a plurality (eight in this embodiment) of substrate mounting holes 132 for attaching a circuit board, which is equipped with a control circuit for controlling semiconductor elements Su1 to Sw2, to the case portion 11 and the base portion 13. The substrate mounting holes 132 are formed to penetrate the peripheral edge 133. When the case portion 11 is attached to the base portion 13, the substrate mounting holes 132 are positioned to overlap with the positions of the substrate mounting holes 112 provided in the case portion 11. The circuit board is fixed to the semiconductor module 1, for example, by attaching nuts from the base portion 13 side to bolts inserted into through holes, substrate mounting holes 112 and substrate mounting holes 132 provided in the circuit board.

[0031] As shown in Figure 2, the semiconductor module 1 has a first projection 117 that protrudes from the case portion 11 toward the side where the base portion 13 is placed, having a shape in which the dimensions in a first direction L1 (not shown in Figure 2, see Figure 3) passing through its own center 117a (not shown in Figure 2, see Figure 3) and the dimensions in a second direction L2 (not shown in Figure 2, see Figure 3) intersecting the first direction L1 and passing through the center 117a differ. The center 117a refers to the center of the first projection 117 in a plan view of the case portion 11. In this embodiment, the first direction L1 and the second direction L2 are, for example, orthogonal, but they may intersect at other angles. The semiconductor module 1 has a through hole 137 that is larger than the outer circumference of the first projection 117, has an opening that conforms to the shape of the outer circumference of the first projection 117, penetrates the base portion 13, and into which the first projection 117 is inserted.

[0032] The first projection 117 is located on the short side 111a (one example) of the pair of short sides 111a, 111b (see Figure 1) of the peripheral edge 111 provided on the case portion 11, and the second projections 119a, 119b are located on the short side 111b (the other example) of the pair of short sides 111a, 111b of the peripheral edge 111. Therefore, the through hole 137 is formed in the short side 133a of the pair of short sides 133a, 133b of the peripheral edge 133 provided on the base portion 13.

[0033] Furthermore, the first projection 117 is positioned near the corner where the short side 111a and the long side 111d intersect (an example of a corner) of the four corners of the case portion 11. Therefore, the through hole 137 is formed near the corner where the short side 133a and the long side 133d intersect of the four corners of the base portion 13. The second projections 119a and 119b are positioned near the corners diagonally opposite the corner where the short side 111a and the long side 111d intersect (short side 111b They are positioned on the short side portion 113b of the pair of short side portions 113a, 113b of the side wall 113 of the case portion 11 and on the long side portion 113c (one example) of the pair of long side portions 113c, 113d of the side wall 113, with the corner portion where the long side portion 111c intersects in between.

[0034] In the semiconductor module 1, in a plan view of the case portion 11 and the base portion 13, the corners located diagonally opposite each other on the side wall 113 of the case portion 11 are at their furthest points from each other. Therefore, the first projection 117 and the through hole 137, and the second projections 119a and 119b are located near the furthest points from each other in the semiconductor module 1 in a plan view of the base portion 13.

[0035] The first projection 117 and the through hole 137 are used for positioning when attaching the case portion 11 to the base portion 13. The through hole 137 has an opening larger than the outer shape of the first projection 117. Therefore, when attaching the case portion 11 to the base portion 13, the case portion 11 may rotate within the plane of the peripheral portion 111 on which the first projection 117 is formed, with the first projection 117 as the axis of rotation. The amount of rotation associated with this rotation is smallest near the first projection 117 and largest at the corner of the case portion 11 diagonally opposite to the corner on which the first projection 117 is provided (i.e., the corner where the short side portion 113b and the long side portion 113c of the side wall 113 intersect). The semiconductor module 1 is equipped with a second projection 119a formed on the short side portion 113b and a second projection 119b formed on the long side portion 113c. Therefore, when attaching the case portion 11 to the base portion 13, even a slight rotation of the case portion 11 relative to the base portion 13 around the first projection 117 as the axis of rotation will cause the second projection 119a or the second projection 119b to come into contact with the side surface 139 of the base portion 13. This prevents the case portion 11 from rotating relative to the base portion 13, thereby improving the mounting accuracy of the case portion 11 to the base portion 13 and the efficiency of the mounting work.

[0036] The first projection 117 and the columnar portion 115 are arranged in a substantially straight line, sandwiching the peripheral edge 133 provided on the base portion 13 and the peripheral edge 111 provided on the case portion 11. As a result, the first projection 117 and the columnar portion 115 are arranged substantially coaxially. The first projection 117 serves as a reference when attaching the case portion 11 and the base portion 13, and the columnar portion 115 serves as a reference when attaching the circuit board to the semiconductor module 1. Therefore, the semiconductor module 1 can consolidate various attachment references within a predetermined area.

[0037] (Configuration of the first projection, second projection, and through hole) Next, an example of the schematic configuration of the first projection 117, the second projections 119a, 119b, and the through hole 137 provided in the semiconductor module 1 according to this embodiment will be described with reference to Figures 1 and 2, and with reference to Figures 3 and 4. first The general configuration of the first projection 117 and the through hole 137 will be explained using Figure 3. Figure 3 is an enlarged view of the vicinity of the first projection 117 and the through hole 137. The upper left of Figure 3 shows a plan view of the first projection 117 and the through hole 137. The lower left of Figure 3 shows a cross-section of the first projection 117 and the through hole 137 cut along the first direction L1. The right side of Figure 3 shows a cross-section of the first projection 117 and the through hole 137 cut along the second direction L2.

[0038] As shown in Figure 3, the first projection 117 is integrally formed with the short side portion 111a of the peripheral edge portion 111 provided on the case portion 11. The first projection 117 is formed on the surface 111a-1 of the short side portion 111a that faces the short side portion 133a of the peripheral edge portion 133 provided on the base portion 13. The first projection 117 is formed to protrude from the surface 111a-1. The first projection 117 is formed such that its height relative to the surface 111a-1 is higher than that of the short side portion 133a.

[0039] The first projection 117 has a rectangular parallelepiped shape, and its surface is formed in a curved shape. In this embodiment, the first direction L1 is set, for example, in the longitudinal direction of the first projection 117, and the second direction L2 is set, for example, in the short direction of the first projection 117. Therefore, the first projection 117 has a shape in which the first direction L1 is longer than the second direction L2, and is arranged along the longitudinal direction of the base portion 13 with the first direction L1 aligned. In other words, the first projection 117 is arranged along the longitudinal direction of the case portion 11 with the first direction L1 aligned. Also, in this embodiment, the center 117a of the first projection 117 is set at the center of the first projection 117 when viewed in a direction perpendicular to the surface 111a-1 (i.e., in a plan view).

[0040] As shown in Figure 3, the through hole 137 has an opening large enough to surround the first projection 117 when the case portion 11 is attached to the base portion 13. The through hole 137 has a shape that follows the outer circumference of the first projection 117. Therefore, the through hole 137 has an elongated shape in plan view. Thus, because the first projection 117 has a shape (a rectangular parallelepiped shape in this embodiment) with different dimensions in the first direction L1 and the second direction L2, and the through hole 137 has a shape (an elongated shape in this embodiment) that follows the outer circumference of the first projection 117, the case portion 11 is less likely to rotate around the first projection 117 as an axis of rotation when the case portion 11 is attached to the base portion 13.

[0041] In semiconductor module 1, the first projection 117 is used as a reference for positioning the case portion 11 and the base portion 13 when attaching the case portion 11 to the base portion 13. The reference value (i.e., design value) of the dimension of the first projection 117 in the first direction L1 is defined as "a1", and the reference value (i.e., design value) of the dimension of the through hole 137 in the first direction L1 is defined as "b1". As shown in Figure 3, when the dimensions of the first projection 117 and the dimensions of the through hole 137 are the reference values, and the first projection 117 is positioned in the center of the through hole 137, the stacking tolerance T1 in the first direction L1 of semiconductor module 1 can be expressed by the following equation (1). T1 = a1 - b1 ... (1)

[0042] Let "a2" be the reference value (i.e., design value) for the dimension of the first projection 117 in the second direction L2, and "b2" be the reference value (i.e., design value) for the dimension of the through hole 137 in the second direction L2. As shown in Figure 3, when the dimensions of the first projection 117 and the dimensions of the through hole 137 are at the reference values, and the first projection 117 is positioned in the center of the through hole 137, the stacking tolerance T2 in the second direction L2 of the semiconductor module 1 can be expressed by the following equation (2). T2 = a2 - b2 ... (2)

[0043] Let "Δa1" be the upper and lower tolerances of the reference value a1 for the dimension of the first projection 117 in the first direction L1. Also, let "Δb1" be the upper and lower tolerances of the reference value b1 for the dimension of the through hole 137 in the first direction L1. The relative position of the base portion 13 and the case portion 11 deviates the most from the reference state in the first direction L1 when the dimension of the case portion 11 in the first direction L1 is at its minimum and the dimension of the base portion 13 in the first direction L1 is at its maximum. Here, the reference state is the state shown in Figure 3, that is, the state in which the first projection 117 is positioned in the center of the through hole 137 in a plan view. Therefore, in the semiconductor module 1, the maximum deviation of the case portion 11 and the base portion 13 in the first direction L1, i.e., the maximum stacked tolerance T1n, can be expressed by the following equation (3). 。 T 1n = (b1 + Δb1) - (a1 - Δa1) =(b1-a1)+(Δb1+Δa1) ···(3)

[0044] The upper and lower tolerances of the reference value a2 for the dimension of the first projection 117 in the second direction L2 are set to "Δa2". Also, the upper and lower tolerances of the reference value b2 for the dimension of the through hole 137 in the second direction L2 are set to "Δb2". The relative position of the base portion 13 and the case portion 11 deviates the most from the reference state in the second direction L2 when the dimension of the case portion 11 in the second direction L2 is at its minimum and the dimension of the base portion 13 in the second direction L2 is at its maximum. Therefore, in the semiconductor module 1, in the second direction L2 maximum The cumulative tolerance T2n can be expressed by the following equation (4). 。 T 2n = (b² + Δb²) - (a² - Δa²) =(b2-a2)+(Δb2+Δa2) ···(4)

[0045] As shown in equations (1) to (4), in the semiconductor module 1 according to this embodiment, the dimensions of the first projection 117 formed in the case portion 11 and the through hole 137 formed in the base portion 13 affect the cumulative tolerance related to the misalignment of the case portion 11 and the base portion 13.

[0046] Next, the configuration of the second protrusions 119a and 119b will be explained using Figure 4. The second protrusions 119a and 119b have the same configuration. Therefore, the configuration of the second protrusions 119a and 119b will be explained using the second protrusion 119a as an example. Figure 4 is an enlarged view of the second protrusion 119a. 2 The image shows a cross-sectional view of a portion of semiconductor module 1, cut using alpha-alpha radiation.

[0047] As shown in Figure 4, the second projection 119a is integrally formed with the short side portion 113b of the side wall 113 provided on the case portion 11. The second projection 119a is positioned opposite the short side portion 133b of the peripheral edge portion 133 provided on the base portion 13. The second projection 119a is formed to protrude from the opposing surface 113b-1 where the short side portion 113b faces the short side portion 133b. The second projection 119a is positioned from the surface of the case portion 11 that is bonded to the base portion 13 to the end portion 113e of the side wall 113 of the case portion 11.

[0048] The second projection 119a moves away from the end 113e side of the side wall 113 of the case portion 11, and is relative to the side wall 113 of the case portion 11. Low It has an inclined surface 119a-1 that slopes in a certain direction. For this reason, the second projection 119a has a rectangular parallelepiped shape with a part of its corner missing. The case portion 11 is attached to the base portion 13 from the end 113e side of the side wall 113. When the second projections 119a and 119b are provided, the gap between the side wall 113 of the case portion 11 and the side surface 139 of the base portion 13 becomes narrower. When the case portion 11 is attached to the base portion 13, the case portion 11 is guided to the base portion 13 by the inclined surface 119a-1 of the second projection 119a. As a result, the case portion 11 can be attached to the base portion 13 without getting caught.

[0049] The clearance C2 between the second projection 119a and the side surface 139 of the base portion 13 is greater than the clearance C1 between the first projection 117 and the inner wall surface 137a of the base portion 13 defining the through hole 137. More specifically, the first projection 117, the through hole 137, and the second projection 119a are formed such that the clearance C2 between the second projection 119a and the portion of the short side 133b of the side surface 139 of the base portion 13 is greater than the clearance C1 between the end portion 117b of the first projection 117 and the inner wall surface 137a of the base portion 13 defining the through hole 137. Although not shown in the diagram, the clearance between the second projection 119b and the side surface 139 of the base portion 13 (more specifically, the portion on the long side 133c) is greater than the clearance C1 between the first projection 117 and the inner wall surface 137a of the base portion 13 that defines the through hole 137.

[0050] In this way, by forming the first projection 117, the through hole 137, and the second projections 119a and 119b such that the clearance C2 at the second projections 119a and 119b is larger than the clearance C1 at the first projection 117, the case portion 11 can effectively suppress rotational displacement when the case portion 11 is attached to the base portion 13, with the first projection 117 as the axis of rotation.

[0051] (Effects of semiconductor modules) Next, the effects of the semiconductor module 1 according to this embodiment will be explained with reference to Figure 3 and using Figure 5. Figure 5 is a diagram showing an example of assembly tolerances for a conventional semiconductor module. Figure 5(a) shows a state in which the case portion 91 and the base portion 92 are not misaligned with respect to the jig pin 93. Figure 5(b) shows a state in which the case portion 91 and the base portion 92 are misaligned with respect to the jig pin 93, making it most difficult to attach the case portion 91 to the base portion 92.

[0052] As shown in Figure 5, in a conventional semiconductor module, the case portion 91 is attached to the base portion 92 with reference to a jig pin 93 provided on the assembly apparatus for assembling the semiconductor module. Specifically, in a conventional semiconductor module, through holes 911 formed in the case portion 91 and through holes formed in the base portion 92 921 The jig pin 93 is inserted to position the case portion 91 and the base portion 92.

[0053] As shown in Figure 5(a), the reference value (i.e., design value) of the dimensions of the jig pin 93 is set to "d", the reference value (i.e., design value) of the dimensions of the through hole 911 in the case portion 91 is set to "e", and the through hole in the base portion 92 is set to "d". 921 The reference value (i.e., design value) of the dimension is denoted as "f". As shown in Figure 5(a), the jig pin 93, the through hole 911 of the case portion 91 and the through hole of the base portion 92 921If each of the dimensions is within the standard value and the case portion 91 and base portion 92 are not misaligned with respect to the jig pin 93, the stacking tolerance Tc in a conventional semiconductor module can be expressed by the following formula (5). Tc = (ed) + (fd) =(e+f)-2×d ···(5)

[0054] The upper and lower tolerances of the reference value d for the dimensions of the jig pin 93 are defined as "Δd". The upper and lower tolerances of the reference value e for the dimensions of the through hole 911 of the case portion 91 are defined as "Δe". The through hole of the base portion 92 921 Let "Δf" be the upper and lower tolerances of the reference value f for the dimension. As shown in Figure 5(b), the relative position of the base portion 92 and the case portion 91 deviates the most from the reference state when the case portion 91 and the base portion 92 are shifted to opposite sides relative to the jig pin 93, and the dimension of the jig pin 93 is at its minimum, and the dimensions of the case portion 91 and the base portion 92 are at their maximum. Here, the reference state is the state shown in Figure 5(a), i.e., the jig pin 93, the through hole 911 of the case portion 91 and the through hole of the base portion 92 921 The central axes of each of these coincide. Therefore, in a conventional semiconductor module, the maximum stacking tolerance Tcn, when the central position 91c of the through hole 911 of the case portion 91 is used as the reference, can be expressed by the following equation (6). Tcn=[e+Δe-(d-Δd)]+[f+Δf-(d-Δd)] =[(e+f)-2×d]+(Δe+Δf+2×Δd) ···(6)

[0055] As shown in equations (5) and (6), in conventional semiconductor modules, the jig pin 93, the through hole 911 of the case portion 91 and the through hole of the base portion 92 921 The dimensions of each component, as well as the relative positional relationship between the jig pin 93, the case portion 91, and the base portion 92, affect the stacking tolerance.

[0056] In contrast, as described above, in the semiconductor module 1 according to this embodiment, only the dimensions of the first projection 117 formed on the case portion 11 and the through hole 137 formed on the base portion 13 affect the stacking tolerance. In the semiconductor module 1, the first projection 117 serves as a reference for positioning. For this reason, for example, the reference value a1 of the dimension of the first projection 117 and the reference value d of the dimension of the jig pin 93 are assumed to be equal. Also, the reference value b1 of the dimension of the through hole 137 and the through hole of the base portion 92 are assumed to be equal. 921 Assume that the tolerance Δa1 of the tolerance value a1 of the dimension of the first projection 117 is equal to the tolerance Δd of the tolerance value d of the dimension of the jig pin 93. Furthermore, assume that the tolerance Δb1 of the tolerance value b1 of the dimension of the through hole 137 is equal to the tolerance Δb1 of the through hole of the base portion 92. 921 Assume that the tolerance Δf of the reference value f for the dimension is equal. Then, the difference ΔT between the maximum stack tolerance T1n in semiconductor module 1 and the maximum stack tolerance Tcn in a conventional semiconductor module can be expressed by the following equation (7). ΔT = Tcn - T1n =[(f-b1)-(2×d-a1)+e] +[(Δf-Δb1)+(2×Δd-Δa1)+Δe] ···(7)

[0057] In equation (7), since "b1=f", "Δb1=Δf", "a1=d", and "Δa1=Δd", if we replace "a1" with "d" and "Δa1" with "Δd", equation (7) can be expressed as equation (8). ΔT = (d - Δd) + (e + Δe) ... (8)

[0058] Equation (8) shows the stack tolerance of the dimensions of the jig pin 93 and the dimensions of the through hole 911 in the case portion 91. In other words, the maximum stack tolerance T1n in the semiconductor module 1 according to this embodiment is smaller than the maximum stack tolerance Tcn in a conventional semiconductor module by the amount of the stack tolerance of the reference member (the jig pin 93 in equation (8)) and the single member positioned relative to the reference member (the case portion 91 in equation (8)) in positioning the two members.

[0059] Therefore, the semiconductor module 1 can reduce the mounting tolerance between the case portion 11 and the base portion 13 compared to conventional semiconductor modules. In other words, because the semiconductor module 1 uses the first projection 117 as a positioning reference, it can reduce the mounting tolerance between the case portion 11 and the base portion 13. Furthermore, because the semiconductor module 1 can reduce the mounting tolerance between the case portion 11 and the base portion 13, the probability of a defect occurring where the case portion 11 cannot be attached to the base portion 13 can be reduced. This makes it possible to reduce the cost of the semiconductor module 1.

[0060] As described above, the semiconductor module 1 according to this embodiment includes a base portion 13 having a plurality of semiconductor elements Su1 to Sw2 and a cooler 131 for cooling the plurality of semiconductor elements Su1 to Sw2, a case portion 11 attached to the base portion 13 and defining a space 12 in which the plurality of semiconductor elements Su1 to Sw2 are arranged, a first projection 117 having a shape in which the dimensions in a first direction L1 passing through its own center 117a are different from the dimensions in a second direction L2 intersecting the first direction L1 and passing through the center 117a, and projecting from the case portion 11 toward the side in which the base portion 13 is arranged, and a through hole 137 that is larger than the outer circumference of the first projection 117 and has an opening that conforms to the shape of the outer circumference of the first projection 117, and is formed through the base portion 13 into which the first projection 117 is inserted.

[0061] As a result, the semiconductor module 1 can reduce the mounting tolerance between the case portion 11 and the base portion 13 as an assembly component.

[0062] The present invention is not limited to the embodiments described above, and various modifications are possible. In this embodiment, the first projection has a rectangular shape when viewed in a direction perpendicular to the surface on which the first projection is formed, but the present invention is not limited thereto. The first projection may have other shapes (e.g., an ellipse) as long as the dimensions in two directions passing through the center of the first projection and intersecting each other (perpendicular in this embodiment) are not the same (e.g., a circle) when viewed in a direction perpendicular to the surface on which the first projection is formed.

[0063] In this embodiment, the second projection has a rectangular parallelepiped shape with a portion of its corner missing, but the present invention is not limited thereto. For example, the second projection may be hemispherical, triangular prism-shaped, truncated pyramidal, or truncated cone-shaped.

[0064] The technical scope of the present invention is not limited to the illustrative and described embodiments, but also includes all embodiments that produce effects equivalent to those aimed at by the present invention. Furthermore, the technical scope of the present invention is not limited to the combination of features of the invention defined by the claims, but can be defined by any desired combination of specific features from all disclosed features. [Explanation of Symbols]

[0065] 1. Semiconductor module 11,91 Case section 12 Space 13.92 Base section 14u U-phase multilayer substrate 14V V-phase multilayer circuit board 14W W-phase multilayer substrate 91c center position 93 Jig pins 111,133 Peripheral area 111a, 111b, 113a, 113b, 133a, 133b Short side 111a-1 Surface 111c, 111d, 113c, 113d, 133c, 133d Long side 112 PCB mounting holes 113 Side wall 113b-1 Opposite surface 113e,117b End 114a, 114b Partition section 115 Columnar part 117 First protrusion 117a center 119a,119b Second protrusion 119a-1 Slope 121u U phase space 121v V phase space 121w W phase space 131 Cooler 131a Storage space 132 PCB mounting holes 135a,135b Inlet / outlet 137,911, 921 through hole 137a Inner wall surface 139 Side view a1, a2, b1, b2, d, e, f Reference values C1, C2 clearance L1 1st direction L2 2nd direction Nu,Nv,Nw Negative terminal Ou, Ov, Ow output terminals Pu,Pv,Pw Positive terminal Su1, Su2, Sv1, Sv2, Sw1, Sw2 semiconductor devices T1,T1n,T2,T2n,Tc,Tcn Stacking tolerance Δa1, Δb1, Δd, Δf Tolerance ΔT difference

Claims

1. A base portion having multiple semiconductor elements and a cooler for cooling the multiple semiconductor elements, A case portion attached to the base portion and defining the space in which the plurality of semiconductor elements are arranged, A first projection has a shape in which the dimensions in a first direction passing through its own center and the dimensions in a second direction intersecting the first direction and passing through the center are different, and protrudes from the case portion toward the side where the base portion is arranged, A through hole formed that is larger than the outer circumference of the first projection and has an opening that conforms to the shape of the outer circumference of the first projection, and penetrates the base portion into which the first projection is inserted. A semiconductor module equipped with the following features.

2. The case portion has a side wall facing the side surface of the base portion, and a second projection that protrudes from the side wall of the case portion toward the side surface of the base portion. The semiconductor module according to claim 1.

3. The base portion and the case portion each have a rectangular outer shape, The side wall of the case portion has a pair of short sides arranged opposite each other, and a pair of long sides that are stretched across both ends of the pair of short sides and arranged opposite each other. The first projection is positioned on one side of the pair of short sides, The second projection is located on the other side of the pair of short sides. The semiconductor module according to claim 2.

4. The first projection is positioned near one of the four corners of the case portion. The second projection is positioned on the other of the pair of short sides and on one of the pair of long sides, respectively, with the diagonal corner of the first corner in between. The semiconductor module according to claim 3.

5. A base portion having a plurality of semiconductor elements and a cooler for cooling the plurality of semiconductor elements, A case portion attached to the base portion and defining the space in which the plurality of semiconductor elements are arranged, A first projection has a shape in which the dimensions in a first direction passing through its own center and the dimensions in a second direction intersecting the first direction and passing through the center are different, and protrudes from the case portion toward the side where the base portion is arranged, A through hole formed that is larger than the outer circumference of the first projection and has an opening that conforms to the shape of the outer circumference of the first projection, and penetrates the base portion into which the first projection is inserted. Equipped with, The case portion has a side wall facing the side surface of the base portion, and a second projection that protrudes from the side wall of the case portion toward the side surface of the base portion. The base portion and the case portion are rectangles having a pair of long sides and a pair of short sides in a plan view. The first projection is located on one of the shorter sides, on the side furthest from the longer side. The second projection is positioned on the other short side and the one long side, respectively, straddling the corner between the other short side and the one long side. Semiconductor module.

6. Having mounting holes for attaching the base portion and the case portion, The mounting hole is located on a straight line connecting the second projection located on the other short side and the second projection located on the one long side. The semiconductor module according to claim 5.

7. The first projection has a shape in which the first direction is longer than the second direction, and is arranged along the longitudinal direction of the base portion with the first direction aligned. A semiconductor module according to any one of claims 3 to 6.

8. The second projection has an inclined surface that slopes downward relative to the side wall of the case portion as it moves away from the end of the side wall of the case portion. A semiconductor module according to any one of claims 2 to 7.

9. The clearance between the second projection and the side surface of the base is greater than the clearance between the first projection and the through hole. A semiconductor module according to any one of claims 2 to 8.

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