Semiconductor module housing and manufacturing method of semiconductor module housing

Abstract

Even in a short time, a sufficient amount of resin can be supplied into the mold to obtain a good molded product. The housing (11) of the semiconductor module houses the semiconductor element and is a box-shaped structure with an opening at the bottom, formed by injection molding. The housing has a rectangular shape when viewed from above, and external terminals are arranged on the upper surface or side. The external terminals are electrically connected to the semiconductor element on the inside of the housing and extend through the inside and outside of the housing. The housing has a single first gate (52) on one side corresponding to the short side of the rectangular shape as a resin inlet. The first gate has a flat shape that is longer in the width direction of the housing.

Description

Technical Field

[0001] This invention relates to a housing for a semiconductor module and a method for manufacturing the housing for a semiconductor module. Background Technology

[0002] Semiconductor devices have substrates containing semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors), power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), and FWDs (Free Wheeling Diodes), and are used in inverter devices, etc.

[0003] In this semiconductor module, semiconductor elements disposed on a predetermined substrate are housed, for example, in a resin housing. The housing used in the semiconductor module is mass-produced, for example, using injection molding technology. In injection molding, heated and molten resin is injected into a mold, and the desired molded product is produced through processes such as pressurization, cooling, and curing (see, for example, Patent Documents 1-4).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 4-267115

[0007] Patent Document 2: Japanese Patent Application Publication No. 8-197564

[0008] Patent Document 3: Japanese Patent Application Publication No. 2001-54920

[0009] Patent Document 4: Japanese Patent Application Publication No. 2014-171440 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] However, in high-capacity semiconductor modules, the increased size of the housing necessitates a greater resin supply within a shorter molding time. For example, if insufficient resin is injected into the mold due to a short injection time, the wall thickness of the molded part may not be adequately ensured, resulting in defects. Furthermore, to ensure sufficient resin filling, a faster injection speed is considered. However, if the resin injection speed is too fast, air is entrained within the mold, becoming a major cause of resin voids. Thus, the changes in injection molding conditions accompanying the increase in housing size can potentially lead to various constraints.

[0012] The present invention was made in view of the above-mentioned problems, and one of its objectives is to provide a semiconductor module housing and a method for manufacturing the semiconductor module housing, which can supply a sufficient amount of resin into the mold to obtain a good molded product even in a short time.

[0013] Solution for solving the problem

[0014] The semiconductor module housing of one embodiment of the present invention is a box-shaped structure with an opening at the bottom and is formed by injection molding. The housing of the semiconductor module has a rectangular shape when viewed from above, and external terminals are disposed on the upper surface or side surface. The external terminals are electrically connected to the semiconductor element on the inner side of the housing and penetrate the inner and outer sides of the housing. A single first gate portion is provided on one side corresponding to the short side of the rectangular shape as an inlet for resin. The first gate portion has a flat shape that is longer in the width direction of the housing.

[0015] A method for manufacturing the housing of the semiconductor module according to a technical solution of the present invention includes the following steps: filling resin into a mold through the first gate portion; and removing a resin flow path portion connected to the housing, the resin flow path portion having a flow channel portion connected to the first gate portion to form a passage for the resin, the flow channel portion having a thin sheet shape that is longer in the width direction of the housing, and inclined in a manner that the thickness decreases as it moves toward the first gate portion.

[0016] The effects of the invention

[0017] According to the present invention, a sufficient amount of resin can be supplied into the mold even in a short time to obtain a good molded article. Attached Figure Description

[0018] Figure 1 This is a perspective view of the semiconductor module involved in this embodiment.

[0019] Figure 2 This is a top view of the semiconductor module involved in this embodiment.

[0020] Figure 3 It is self Figure 2 The semiconductor module shown is a top view with its housing removed.

[0021] Figure 4 This is a three-dimensional view of the area around the gate of the shell involved in the reference example.

[0022] Figure 5 This is a perspective view of the area around the gate of the shell involved in this embodiment.

[0023] Figure 6 This is a cross-sectional view of the periphery of the gate of the shell involved in this embodiment.

[0024] Figure 7 This is a perspective view of the housing involved in this embodiment, viewed from other directions. Detailed Implementation

[0025] The following describes a semiconductor module to which the present invention can be applied. Figure 1 This is a perspective view of the semiconductor module involved in this embodiment. Figure 2 This is a top view of the semiconductor module involved in this embodiment. Figure 3 It is self Figure 2 The semiconductor module shown is a top view with its housing removed. Figure 2 and Figure 3 For ease of explanation, the main terminals and control terminals have been omitted. Furthermore, the semiconductor module shown below is merely an example and is not limited to it; appropriate modifications are permissible.

[0026] In the following figures, the long side direction of the semiconductor module (the direction in which multiple stacked substrates are arranged) is defined as the X direction, the short side direction as the Y direction, and the height direction (the thickness direction of the substrate) as the Z direction. The X, Y, and Z axes in the figures are orthogonal to each other, forming a right-handed system. Additionally, depending on the situation, the X direction may sometimes be referred to as the left-right direction, the Y direction as the front-back direction, and the Z direction as the up-down direction. These directions (front-back, left-right, up-down) are terms used for ease of explanation, and their correspondence with the X, Y, and Z directions may change depending on the mounting orientation of the semiconductor module. For example, the heat dissipation surface side (cooler side) of the semiconductor module may be called the lower surface side, and its opposite side as the upper surface side. Furthermore, in this specification, "top view" refers to the view of the upper surface of the semiconductor module from the Z-direction. Also, in this specification, the descriptions of directions and angles are only approximate and are permissible within ±10 degrees.

[0027] The semiconductor module involved in this embodiment, for example, is used in power conversion devices such as power modules, and is a power module constituting an inverter circuit. Figures 1-3 As shown, the semiconductor module 1 is configured to include: a base plate 10; a plurality of stacked substrates 2 disposed on the base plate 10; a plurality of semiconductor elements 3 and 4 disposed on the stacked substrates 2; a housing 11 that houses the stacked substrates 2 and the plurality of semiconductor elements; and a sealing resin (not shown) that fills the housing 11.

[0028] The base plate 10 is a rectangular plate with an upper surface and a lower surface. The base plate 10 functions as a heat sink. Furthermore, the base plate 10 has a rectangular shape in plan view, with a long side in the X direction and a short side in the Y direction. The base plate 10 may be a metal plate made of, for example, copper, aluminum, or their alloys, and its surface may be plated.

[0029] A housing 11, which is rectangular in shape when viewed from above, is disposed on the upper surface of the base plate 10. The housing 11 is formed as a box-shaped cuboid with an opening at the bottom and having a frame portion forming side walls and a cover portion covering the top. The housing 11 covers the top of the base plate 10 and defines a space for accommodating the laminated substrate 2, semiconductor components, sealing resin, etc.

[0030] Additionally, external terminals are provided on the housing 11. Specifically, the external terminals consist of a positive terminal 12 (P terminal), a negative terminal 13 (N terminal), and an output terminal 14 (M terminal). The positive terminal 12, negative terminal 13, and output terminal 14 can also be referred to as main terminals. Furthermore, the external terminals may include multiple control terminals 15. One end of the external terminal is connected to a predetermined circuit board inside the housing 11. The external terminal extends through the housing 11, with one end positioned inside the housing 11 and the other end protruding from the upper surface of the housing 11 outwards (outwards). The other end of the external terminal can be electrically connected to an external device. The other ends of the multiple main terminals (positive terminal 12, negative terminal 13, and output terminal 14) are arranged in the X direction, which is the long side. The other ends of the multiple main terminals are located on the upper surface of the housing 11, biased towards the positive side in the X direction and positioned at the center in the Y direction. The other ends of the multiple control terminals 15 are arranged in the X direction, which is the long side. The other end of the plurality of control terminals 15 is biased toward the negative side in the X direction on the upper surface of the housing 11 and is disposed at the end in the Y direction.

[0031] Specifically, a terminal configuration portion 11a for arranging main terminals and a terminal configuration portion 11b for arranging control terminals 15 are formed on the upper surface of the housing 11. The terminal configuration portion 11a has a cuboid shape that protrudes from the upper surface of the housing 11 along the Z direction and is longer in the X direction. The terminal configuration portion 11a is located on the upper surface of the housing 11, biased towards the positive side in the X direction and positioned at the center in the Y direction.

[0032] The terminal mounting portion 11b is disposed on the upper surface of the protrusion 17 described below. The terminal mounting portion 11b may also not protrude from the upper surface of the housing 11 along the Z direction. The terminal mounting portion 11b is disposed on the upper surface of the housing 11, biased towards the negative side in the X direction, and at the end in the Y direction.

[0033] Furthermore, a plurality of countersunk holes 16 for module fixing are formed on a pair of opposing long sides (outer surfaces) of the housing 11 in the Y direction. The plurality of countersunk holes 16 are arranged in the X direction, for example, seven on each side. Using the plurality of countersunk holes 16, a plurality of protrusions 17 are formed on the opposing sides of the housing 11 in the Y direction. A specific protrusion 17 located on the negative side in the X direction constitutes a terminal arrangement portion 11b. That is, the terminal arrangement portion 11b is arranged biased towards the negative side in the X direction.

[0034] Furthermore, a plurality of grooves 11f are formed along the X direction on a pair of long sides (outer surfaces) opposite each other in the Y direction of the housing 11. The grooves 11f are formed on the outer peripheral surface of the defined protrusion 17 where the terminal mounting portion 11b is disposed and the outer peripheral surface of the countersunk hole 16. That is, the grooves 11f are disposed biased towards the negative side in the X direction.

[0035] Furthermore, a side surface 11c, 11d with a flat YZ surface is formed on a pair of opposite short sides (outer sides) of the housing 11 in the X direction. Alternatively, countersunk holes 16 may be formed at both ends in the Y direction. That is, the side surface 11c, 11d with a flat YZ surface is formed at the center of the short side.

[0036] like Figure 2 As shown, a storage portion 18 for securing nuts (not shown) to external conductors using screws is formed on the upper surface of terminal arrangement portions 11a and 11b. For example, six storage portions 18 are arranged in the X direction. The storage portions 18 have a top-view hexagonal shape corresponding to the shape of the nuts. Furthermore, a slit 19 for terminal insertion is formed on the side of the storage portion 18. The slit 19 extends through the upper surface of the housing in the thickness direction (Z direction) in a stripe-like pattern with a longer length in the X direction. Additionally, the storage portions 18 and slits 19 formed in terminal arrangement portion 11b are smaller than those formed in terminal arrangement portion 11a.

[0037] like Figure 1 As shown, on the upper surface of the terminal arrangement section 11a, a positive terminal 12, a negative terminal 13, and an output terminal 14 are arranged sequentially from the negative side in the X direction. Additionally, a control terminal 15 is arranged on the upper surface of the terminal arrangement section 11b. One end of each terminal is inserted into the slit 19 and bonded to the laminated substrate 2 within the housing 11. The other end of each terminal is bent at a right angle to cover the top of the receiving section 18. A through-hole is formed in the center of each bent terminal, corresponding to the receiving section 18. The through-hole extends through the thickness direction (Z direction) of the terminal. Each external terminal is formed by stamping or other processes on a metal sheet made of copper, copper alloy, aluminum alloy, or iron alloy.

[0038] In addition, such as Figure 3As shown, six stacked substrates 2 are disposed on the upper surface of the base plate 10 inside the housing 11. The stacked substrates 2 are, for example, formed into a rectangular shape when viewed from above. The six stacked substrates 2 are arranged in the X direction. The stacked substrates 2 are formed by stacking metal layers and insulating layers, and are, for example, composed of a DCB (Direct Copper Bonding) substrate, an AMB (Active Metal Brazing) substrate, or a metal substrate. Specifically, the stacked substrate 2 has an insulating plate 20, a heat sink (not shown) disposed on the lower surface of the insulating plate 20, and circuit boards 21, 22, and 23 disposed on the upper surface of the insulating plate 20.

[0039] The insulating plate 20 is formed as a flat plate having a predetermined thickness in the Z direction and having an upper surface and a lower surface. The insulating plate 20 is formed from insulating materials such as ceramic materials like alumina (Al2O3), aluminum nitride (AlN), and silicon nitride (Si3N4), resin materials like epoxy, or epoxy resin materials using ceramic materials as fillers. Furthermore, the insulating plate 20 may also be referred to as an insulating layer or insulating film.

[0040] The heat sink is formed to have a specified thickness in the Z direction, covering approximately the entire lower surface of the insulating plate. The heat sink is formed, for example, from a metal plate with good thermal conductivity such as copper or aluminum.

[0041] On the upper surface (main surface) of the insulating plate 20, three circuit boards 21, 22, and 23 are independently formed into an island shape, electrically insulated from each other. In addition to the three circuit boards 21, 22, and 23, two circuit boards 24 are also provided as control circuit boards. The two circuit boards 24 are located at opposite corners of the insulating plate 20. These circuit boards are constructed of a metal layer of a specified thickness formed using copper foil or the like.

[0042] The ends of the aforementioned external terminals are connected to the upper surface of these circuit boards. Each end of these external terminals is directly connected to the upper surface of the specified circuit board using ultrasonic bonding, laser bonding, or other methods, or connected to the upper surface of the specified circuit board via solder, sintered metal, or other bonding materials. Thus, the ends of each external terminal are electrically connected to the specified circuit board. For convenience, the description of the connection relationship between each external terminal and the circuit board is omitted.

[0043] Multiple semiconductor elements 3 and 4 are disposed on the upper surfaces of circuit boards 21 and 22 via bonding materials such as solder. Thus, the lower surface electrodes of each semiconductor element 3 and 4 are electrically connected to circuit boards 21 and 22. Consequently, each external terminal is electrically connected to each semiconductor element.

[0044] Semiconductor elements 3 and 4 are formed from semiconductor substrates such as silicon (Si), silicon carbide (SiC), and gallium nitride (GaN) into a rectangular shape in top view. Furthermore, semiconductor elements 3 and 4 may be switching elements such as IGBTs (Insulated Gate Bipolar Transistors), power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), or diodes such as FWDs (Free Wheeling Diodes). In this embodiment, one semiconductor element 3 is designated as an IGBT, and the other semiconductor element 4 as a diode. Alternatively, RC (Reverse Conducting) IGBTs integrating IGBTs and FWDs, power MOSFETs, or RB (Reverse Blocking) IGBTs with sufficient reverse bias withstand voltage can also be used. The shape, number, and placement of the semiconductor elements can be appropriately varied. In this embodiment, the semiconductor element is a vertically shaped switching element formed by forming functional elements such as transistors on a semiconductor substrate.

[0045] In this embodiment, semiconductor elements 3 and 4 are arranged sequentially along the Y direction on the upper surface of circuit board 21. In circuit board 21, semiconductor element 3 is located on the positive side of the Y direction, and semiconductor element 4 is located on the negative side of the Y direction. Similarly, semiconductor elements 3 and 4 are arranged sequentially along the Y direction on the upper surface of circuit board 22. In circuit board 22, semiconductor element 4 is located on the positive side of the Y direction, and semiconductor element 3 is located on the negative side of the Y direction. In this embodiment, semiconductor elements 3 and 4 on circuit board 21 constitute the upper arm, and semiconductor elements 3 and 4 on circuit board 22 constitute the lower arm.

[0046] Furthermore, semiconductor elements 3 and 4, arranged in the Y direction, are electrically connected using wiring components. Additionally, semiconductor element 4 is electrically connected to a predetermined circuit board using wiring components. Furthermore, the gate electrode of semiconductor element 3 is electrically connected to circuit board 24 using wiring components.

[0047] These wiring components use conductive wires (connecting wires). The conductive wires can be made of any one of gold, copper, aluminum, gold alloys, copper alloys, aluminum alloys, or combinations thereof. Furthermore, components other than conductive wires can also be used as wiring components. For example, strips can be used as wiring components. Additionally, the wiring components are not limited to wires; they can also be formed from metal sheets made of copper, copper alloys, aluminum alloys, iron alloys, etc.

[0048] However, as mentioned above, the mass production of semiconductor module housings (also referred to as terminal housings) utilizes injection molding technology. In this injection molding process, the product is manufactured, for example, using the following steps.

[0049] (1) Supply resin particles, which serve as the shell material, into the cylinder of the molding machine.

[0050] (2) The resin is plasticized (melted) by heating it inside the cylinder.

[0051] (3) By rotating the screw inside the cylinder, the resin is injected into the mold at high temperature and high pressure.

[0052] (4) Pressurize, cool and solidify the resin in the mold, then open the mold and remove the molded product using push rods, etc.

[0053] (5) The unwanted parts of the molded product (such as the resin flow path) are cut off to obtain the product.

[0054] Furthermore, in high-capacity semiconductor modules, the increased size of the casing necessitates a greater supply of resin within a shorter molding time. Extending the molding time leads to increased production cycle time, becoming a major cause of cost increases. Additionally, the decreased temperature and reduced fluidity of the molten resin can also contribute to molding defects. Therefore, to produce molded products at low cost and with high quality, the molding time needs to be shortened.

[0055] To shorten production cycle time, one approach is to shorten the resin injection time. However, insufficient resin filling in the mold may result in inadequate wall thickness of the molded part, leading to defects. Conversely, increasing the injection speed is also considered to ensure sufficient resin filling. However, if the injection speed is too fast, air is trapped within the mold, becoming a major cause of resin voids. Furthermore, if the mold holding time (pressurization time) is too short, the resin may not fully cure and may flow back, causing shrinkage. Thus, the changes in injection molding conditions associated with larger housings may bring various constraints.

[0056] Therefore, the inventors of this application conceived of this invention by focusing on the shape of the resin inlet, i.e., the gate, relative to the shell mold. Hereinafter, reference is made to... Figures 4 to 6 The housing of the semiconductor module and the method for manufacturing the housing according to this embodiment will be described in detail. Figure 4 This is a three-dimensional view of the area around the gate of the shell involved in the reference example. Figure 5 This is a perspective view of the area around the gate of the shell involved in this embodiment. Figure 6 This is a cross-sectional view of the periphery of the gate of the shell involved in this embodiment. Figure 4 A, Figure 5 A and Figure 6 A indicates the state where the molded product has just been removed from the mold. Figure 4 B Figure 5 B and Figure 6 B indicates the state where the unwanted part (resin flow path part) of the self-molded product has been cut off.

[0057] like Figure 4 As shown in Figure A, in the molded article of the reference example, the resin passage from the injection molding machine to the mold (neither shown) remains as an unnecessary part (resin flow path portion 5). Specifically, the resin flow path portion 5 is configured to include a sprue portion 50 connected to the injection molding machine, a runner portion 51 connected to the sprue portion 50, and a pair of gate portions 52 connecting the runner portion 51 and the housing 11.

[0058] The sprue section 50 is a passage for transferring resin from the nozzle of the injection molding machine to the runner section 51. Specifically, the sprue section 50 has a cylindrical shape extending in the Z direction. In addition, the sprue section 50 has a tapered shape that gradually widens from the upper end to the lower end. The lower end of the sprue section 50 extends through the runner section 51.

[0059] The runner section 51 is a passageway for guiding resin from the sprue section 50 into the mold cavity. Specifically, the runner section 51 has a first runner section 51a and a pair of second runner sections 51b. The first runner section 51a has a cylindrical shape extending from the lower end side of the sprue section 50 in the Y direction to both sides. The first runner section 51a has a length corresponding to the width of the housing 11 in the Y direction. The pair of second runner sections 51b have cylindrical shapes extending from both ends of the first runner section 51a towards the positive side in the X direction. The second runner sections 51b extend towards one side 11c of the housing 11.

[0060] The gate portion 52 serves as a passage connecting the runner portion 51 (second runner portion 51b) and the mold, forming an inlet for the resin relative to the mold. Specifically, the gate portion 52 has a prism shape extending from the top of each second runner portion 51b toward one side 11c of the housing 11. Furthermore, the gate portion 52 has a rectangular cross-section smaller than the outer diameter of the second runner portion 51b. For example, the cross-sectional area of ​​each gate portion 52 is 3mm × 5mm = 15mm². 2 .

[0061] exist Figure 4 In the illustrated example, as described above, two gate sections 52 with relatively small cross-sectional areas are provided. Therefore, in the case of a relatively large shell, it may be impossible to fill the mold with a sufficient amount of resin when injecting resin into it. Furthermore, since multiple gate sections 52 are present, a confluence of resin entering from each gate section 52 occurs within the mold. This confluence of resin may subsequently become a site that affects the strength of the shell.

[0062] In addition, such as Figure 4 As shown in Figure B, in the cross-section 52a of the gate portion 52 after the resin flow path portion 5 has been removed, a burr protrudes from one side 11c of the housing 11 at a predetermined height, serving as a residual portion of the gate portion 52. For example, the height of the burr is 0.5 mm to 2.0 mm. This burr may interfere with the dedicated jig during subsequent assembly processes, causing poor component installation; therefore, it is preferable to keep it as small as possible. It is particularly preferable that the protrusion height of the burr is small.

[0063] In contrast, Figure 5 In the structure shown in this application, the gating section 51, which forms part of the resin passage, has a sheet shape. Specifically, as Figure 5 As shown in Figure A, the resin flow path portion 5 is configured to include a sprue portion 50 connected to an injection molding machine, a runner portion 51 connected to the sprue portion 50, and a gate portion 52 (first gate portion) connecting the runner portion 51 and the housing 11. Furthermore, the sprue portion 50 is connected to... Figure 4 The structure is the same, so the explanation is omitted.

[0064] The runner section 51 is a passage for introducing resin from the sprue section 50 into the mold cavity. Specifically, the runner section 51 has a first runner section 51a and a second runner section 51b. The first runner section 51a has a cylindrical shape extending from the lower end side of the sprue section 50 in the Y direction to both sides. The first runner section 51a has a length corresponding to the width of the housing 11 in the Y direction.

[0065] The second runner section 51b extends in a film-like manner from the side of the first runner section 51a toward one side 11c of the shell 11 in the X direction. The second runner section 51b is longer in the width direction (Y direction) of the shell 11 and has a thickness in the Z direction. In addition, the second runner section 51b has a tapered shape that decreases in thickness as it moves toward the X direction (the side of the gate section 52 described later). Its inclination angle is, for example, about 15 degrees.

[0066] The gate portion 52 serves as a passage connecting the runner portion 51 (second runner portion 51b) and the mold, forming an inlet for the resin relative to the mold. The gate portion 52 has a flat shape that is longer in the width direction (Y direction) of the housing 11. For example, as Figure 5 As shown in Figure B, the area of ​​the cross-section 52a of the gate 52 is 1 mm (thickness in the Z direction) × 40 mm (width in the Y direction) = 40 mm. 2 .

[0067] like Figure 5As shown in Figure B, the housing 11 after removing the resin flow path portion 5 has a cross-section 52a with a single gate portion 52 on one side 11c of the housing 11. The gate portion 52 after removing the resin flow path portion 5 may be a portion with a surface roughness greater than that of one side 11c of the housing 11. Additionally, the gate portion 52 after removing the resin flow path portion 5 may also have burrs protruding from one side 11c of the housing 11 at a predetermined height, forming a residual portion of the gate portion 52. In this case, the height of the burrs is, for example, less than 0.5 mm. Furthermore, the gate portion 52 after removing the resin flow path portion 5 may also be recessed from one side 11c of the housing 11 toward the inner surface of the housing to a predetermined depth. In this case, the depth of the recess is, for example, less than 0.5 mm.

[0068] Thus, the manufacturing method of the shell 11 of this application is configured to include: a process of filling resin into the mold through the above-mentioned resin passage (sprue section 50, runner section 51, gate section 52) (filling process); a process of pressurizing, cooling and curing the resin in the mold to form the shell (molding process); a process of removing the molded article from the mold (removal process); and a process of removing the unwanted part of the molded article (resin flow path section 5 connected to the shell) (resin flow path section removal process).

[0069] As described above, the second runner portion 51b has a thin sheet shape that is longer in the width direction of the housing 11. Furthermore, the gate portion 52, by being connected to the second runner portion 51b, has a flat shape that is longer in the width direction of the housing 11.

[0070] In this embodiment, by employing a flat gate portion 52 with a larger cross-sectional area than the reference example, a large amount of resin can be filled into the mold in a short time. Furthermore, compared to the reference example which has multiple gate portions 52, in this embodiment, by using a single gate portion 52, the welded portions where resin flows together within the mold can be reduced. As a result, the strength of the molded article (shell 11) can be sufficiently ensured.

[0071] Furthermore, in the housing 11 of this application, a flat side surface 11c, 11d in the shape of a YZ plane is formed corresponding to the short side. The side surfaces 11c, 11d are opposite each other in the X direction. In addition, the side surfaces 11c, 11d are formed at the center of the short side. Moreover, a single gate portion 52 is formed at the center of the lower edge of the side surface 11c with the flat YZ plane.

[0072] According to this structure, a single gate 52 is disposed at the center of the lower edge of one side 11c of the short side of the housing 11. Therefore, resin can flow in uniformly without deviation, weld lines can be reduced, and a housing with uniform properties can be manufactured. Furthermore, the gate 52 is formed as a flat surface. Therefore, unwanted parts of the molded article can be easily removed.

[0073] Furthermore, the housing 11 of this application has a plurality of grooves 11f formed on the sides of a pair of long sides along the X direction. Grooves 11f are also formed on the designated protrusions 17 and countersunk holes 16 where the terminal configuration portions 11b are disposed.

[0074] According to this structure, when the resin flows from one end of the housing 11 toward the other end (from the inlet to the outlet), the resin is guided to flow by the groove 11f, thus allowing the resin to smoothly spread to the protrusions 17 and countersunk holes 16 on the side. Therefore, a good molded product can be obtained.

[0075] Furthermore, in the housing 11, a main terminal (positive terminal 12, negative terminal 13, and output terminal 14) is arranged on the positive X-direction side, which is one end side, and a control terminal 15 is arranged on the negative X-direction side, which is the other end side. A single gate portion 52 is provided on one side 11c of the housing 11 located on the other end side.

[0076] According to this structure, a resin inlet is provided on the control terminal 15 side, where the housing shape is relatively complex compared to the main terminal side. Since the resin at the inlet side has a higher temperature and lower viscosity, a good molded product can be obtained by arranging the complex shape of the housing 11 on the inlet side. Furthermore, even if the resin temperature drops and the viscosity slightly increases on the main terminal side, which is relatively far from the inlet, moldability is not an issue due to its relatively simple shape.

[0077] Furthermore, the thickness (length in the Z direction) of the gate portion 52 is preferably 0.5 mm or more and 2.5 mm or less. The thickness (length in the Z direction) of the gate portion 52 is preferably 1 / 100 or more and 1 / 10 or less of the width (length in the Y direction) of the gate portion 52. In particular, the second runner portion 51b has a thin sheet shape that is longer in the width direction of the housing 11, and is inclined in such a way that the thickness decreases as it moves toward the gate portion 52 side. Its inclination angle is preferably, for example, 10 degrees or more and 30 degrees or less. According to these structures, the base end side of the second runner portion 51b is thicker than the gate portion 52 side, thereby improving the rigidity of the base end side.

[0078] On the other hand, the thickness (length in the Z direction) of the gate portion 52 is less than its length (length in the Y direction), and it is thinner than the base end side of the second flow channel portion 51b. Therefore, the stiffness (shear stiffness) in the Z direction is reduced. As a result, when removing the resin flow channel portion 5, it is easy to cut starting from the gate portion 52 by applying force in the Z direction. In addition, the protrusion height of the cross section 52a of the gate portion 52 (the height protruding from one side 11c of the housing 11) can be reduced, which simplifies the removal process of the end face of the gate portion 52.

[0079] In this embodiment, the resin constituting the shell 11 is a thermoplastic resin. Examples of such resins include polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, polybutylene succinate (PBS) resin, polyamide (PA) resin, or acrylonitrile butadiene styrene (ABS) resin. Furthermore, fillers may be added to the resin in the shell 11. Fillers can be ceramics, for example. Examples of such fillers include silica, alumina, boron nitride, or aluminum nitride. In particular, the shell 11 is preferably made of polyamide resin such as nylon 6 or nylon 66 containing any filler.

[0080] As in the aforementioned reference example, when the resin injection speed is increased while the cross-sectional area of ​​the gate portion 52 is small, the temperature around the gate portion 52 increases. As a result, gas may be generated from the resin, leading to whitening of the molded product. In this embodiment, by ensuring the cross-sectional area of ​​the gate portion 52, such resin whitening can be suppressed.

[0081] In addition, in this embodiment, such as Figure 6 As shown in Figure A, the gate portion 52 is located at the lower edge of the housing 11. By positioning the gate portion 52 at the end of the housing 11, it is possible to prevent the gate portion 52 from becoming the starting point for cracks to form in the housing 11.

[0082] Additionally, a downwardly protruding portion 11e is provided at the lower edge of the housing 11. The protrusion 11e is formed into a rectangular frame shape along the outer shape of the housing 11. The gate portion 52 is formed above the protrusion 11e. More specifically, the lower surface of the gate portion 52 is on the same plane as the base end of the protrusion 11e (the lower surface of the housing 11). The protrusion 11e has a shape that follows the outer shape of the base plate 10 and functions as a protrusion for positioning the housing 11 relative to the base plate 10.

[0083] In addition, in this embodiment, such as Figure 7 As shown, a resin storage section 6 corresponding to the resin outlet is formed on one side 11d located at one end of the housing 11. The resin flow path section 5 and the resin storage section 6 are provided at symmetrical positions in the X direction, separated by the housing 11. The resin storage section 6 is configured to include a flow channel section 61 (other flow channel sections) and a single gate section 62 (second gate section) connecting the flow channel section 61 and the housing 11.

[0084] A single gate portion 62 (second gate portion) is formed at the center of the lower edge of a side surface 11d having a flat YZ plane. According to this structure, the single gate portion 62 is disposed at the center of the lower edge of a side surface 11c located on the short side of the housing 11. Furthermore, the gate portion 62 is provided symmetrically to the gate portion 52 in the X direction, separated from the housing 11. Therefore, unwanted resin can flow out uniformly without deviation, weld lines can be reduced, and a housing with uniform properties can be manufactured. Additionally, the gate portion 62 is formed on a flat surface (side surface 11d). Therefore, unwanted parts of the molded article can be easily removed.

[0085] The runner section 61 is configured to include a portion that discharges air entrained by the resin being injected. Specifically, the runner section 61 has a first runner section 61a and a second runner section 61b. The first runner section 61a has a cylindrical shape extending in the Y direction to both sides at a location opposite to one side 11d of the housing 11. The first runner section 61a has a length corresponding to the width of the housing 11 in the Y direction.

[0086] The second runner portion 61b extends in a film-like manner from the side of the first runner portion 61a toward the negative side of the shell 11 in the X direction. The second runner portion 61b is longer in the width direction (Y direction) of the shell 11 and has a thickness in the Z direction. In addition, the second runner portion 61b has a conical shape that decreases in thickness as it moves toward the negative side of the X direction (the gate portion 62 side described later). Its inclination angle is preferably 10 degrees or more and 30 degrees or less.

[0087] The gate portion 62 serves as a passage connecting the runner portion 61 (second runner portion 61b) and the mold, constituting an outlet for the resin relative to the mold. The gate portion 62 has a flat shape that is longer in the width direction (Y direction) of the housing 11. The thickness (length in the Z direction) of the gate portion 62 is preferably 0.5 mm or more and 2.5 mm or less. The thickness (length in the Z direction) of the gate portion 62 is preferably 1 / 100 or more and 1 / 10 or less of the width (length in the Y direction) of the gate portion 62.

[0088] The aforementioned gate portion 62 and runner portion 61 constitute a resin discharge passage for discharging resin that has been entrained by air at the start of injection to the outside of the housing 11. By utilizing the gate portion 62 and runner portion 61, even if air is entrained inside the housing 11, a well-molded product with the air removed can be obtained.

[0089] Furthermore, similar to the inlet side, the thickness (length in the Z direction) of the second runner portion 61b is less than its length (length in the Y direction), and the base end side of the second runner portion 61b is thicker than the gate portion 62 side. Therefore, the stiffness of this base end side is increased. On the other hand, the gate portion 62 is thinner than the base end side of the second runner portion 61b, thus its stiffness in the Z direction is reduced. As a result, by applying force in the Z direction when removing the resin flow path portion 6, cutting can be easily performed starting from the gate portion 62.

[0090] Furthermore, it is preferable that the second flow channel portion 61b on the outlet side is shorter than the second flow channel portion 51b on the inlet side. This is because the second flow channel portion 61b was originally an unnecessary part as part of the resin flow path portion 6, so a shorter portion reduces the amount of resin used in the second flow channel portion 61b, making it more economical.

[0091] As explained above, according to this embodiment, by using a film-shaped gate in the injection-molded shell 11, a sufficient amount of resin can be supplied into the mold even in a short time to obtain a good molded product.

[0092] Furthermore, in the above embodiments, the number and layout of the circuit boards are not limited to the above structure, but can be appropriately changed.

[0093] Furthermore, in the above embodiment, the housing 11 is configured as a box-shaped structure with an opening at the bottom to cover the top of the base plate 10 and a plurality of semiconductor elements, but it is not limited to this structure. The housing 11 may also be a frame-shaped structure with openings at the bottom and top. In this case, it may also be a structure with a housing cover that covers the opening at the top of the housing 11.

[0094] Furthermore, in the above embodiment, the structure is configured such that the housing 11 is disposed on the upper surface of the base plate 10, but it is not limited to this structure. It is also possible to have a structure in which the housing 11 is disposed on the upper surface of the laminated substrate 2 without a base plate 10.

[0095] Furthermore, in the above embodiment, the stacked substrate 2 and the semiconductor element are configured to have a rectangular or square shape when viewed from above, but are not limited to this structure. The stacked substrate 2 and the semiconductor element may also be configured to have a polygonal shape other than those described above.

[0096] Furthermore, while this embodiment and its variations have been described, the above embodiments and variations may be combined in whole or in part as other embodiments.

[0097] Furthermore, this embodiment is not limited to the above-described embodiments and variations, and various changes, substitutions, and modifications can be made without departing from the spirit of the technical concept. Moreover, if the technical concept can be realized in other ways through technological advancements or derived technologies, this method can also be used. Therefore, the technical solution covers all embodiments that can be included within the scope of the technical concept.

[0098] The following is a summary of the feature points in the above embodiments.

[0099] The above embodiment describes a semiconductor module housing that houses semiconductor elements. The housing is a box-shaped structure with an opening at the bottom and is formed by injection molding. The housing of the semiconductor module has a rectangular shape when viewed from above, and external terminals are disposed on the upper surface or side surface. The external terminals are electrically connected to the semiconductor elements on the inner side of the housing and penetrate the inner and outer sides of the housing. A single first gate portion is provided on one side corresponding to the short side of the rectangular shape as an inlet for resin. The first gate portion has a flat shape that is longer in the width direction of the housing.

[0100] Furthermore, in the housing of the semiconductor module described in the above embodiments, a main terminal is disposed on one end of the rectangular shape, a control terminal is disposed on the other end, and the first gate is disposed on one side of the other end.

[0101] Furthermore, in the housing of the semiconductor module described in the above embodiments, a plurality of grooves are formed along the length direction on the side corresponding to the long side of the rectangular shape.

[0102] Furthermore, in the housing of the semiconductor module described in the above embodiments, the thickness of the first gate portion is more than 1 / 100 and less than 1 / 10 of the width of the first gate portion.

[0103] Furthermore, in the housing of the semiconductor module described in the above embodiments, the resin is formed of a polyamide resin with added filler.

[0104] Furthermore, in the housing of the semiconductor module described in the above embodiments, the first gate portion is provided at the lower edge of the housing.

[0105] Furthermore, in the semiconductor module housing described in the above embodiments, a downwardly protruding portion is provided at the lower edge of the housing, and the first gate portion is formed at a position above the protruding portion.

[0106] In addition, in the housing of the semiconductor module described in the above embodiment, a single second gate portion serving as an outlet for the resin is provided on one side located at one end, and the second gate portion has a flat shape that is longer in the width direction of the housing.

[0107] Furthermore, in the housing of the semiconductor module described in the above embodiments, the second gate is provided at a position symmetrical to the first gate.

[0108] In addition, the method for manufacturing the semiconductor module housing described in the above embodiments includes the following steps: filling resin into a mold through the first gate portion; and removing a resin flow path portion connected to the housing, the resin flow path portion having a flow channel portion connected to the first gate portion to form a passage for the resin, the flow channel portion having a thin sheet shape that is longer in the width direction of the housing, and inclined in a manner that the thickness decreases as it moves toward the first gate portion.

[0109] Furthermore, in the method for manufacturing the housing of the semiconductor module described in the above embodiments, the inclination angle of the flow channel portion is 10 degrees or more and 30 degrees or less.

[0110] Furthermore, in the semiconductor module housing manufacturing method described in the above embodiments, a single second gate portion serving as the resin outlet is provided on one side located at one end. The second gate portion has a flat shape that is longer in the width direction of the housing. The resin flow path portion includes other flow path portions connected to the second gate portion to form a passage for the resin. The other flow path portions have a thin sheet shape that is longer in the width direction of the housing, and are inclined in such a way that their thickness decreases as they move toward the second gate portion, and are shorter than the flow path portions.

[0111] Industrial availability

[0112] As explained above, the present invention has the effect of supplying a sufficient amount of resin into the mold even in a short time to obtain a good molded product, and is particularly useful for the manufacturing method of semiconductor module housings and semiconductor module housings.

[0113] This application is based on Japanese Patent Application No. 2020-111131, filed on June 29, 2020. Its entire contents are contained in this specification.

Claims

1. A housing of a semiconductor module that houses a semiconductor element, is a box shape with an opening at a lower side, and is formed by injection molding, wherein the housing of the semiconductor module has a rectangular shape in plan view, and external terminals are arranged on an upper surface or a side surface, the external terminals are electrically connected to the semiconductor element on an inner side of the housing, and pass through the inner side and an outer side of the housing, a single first gate portion that is an inlet of a resin is provided on a side surface on a side corresponding to a short side of the rectangular shape, the first gate portion has a flat shape that is longer in a width direction of the housing, the first gate portion is provided at a lower edge portion of the housing, a protruding portion that protrudes downward is provided at the lower edge portion of the housing, and the first gate portion is formed at a position that is higher than the protruding portion.

2. The housing of the semiconductor module according to claim 1, wherein a main terminal is arranged on one end side of the rectangular shape, and a control terminal is arranged on the other end side, and the first gate portion is arranged on a side surface on the other end side.

3. The housing of the semiconductor module according to claim 1 or 2, wherein a plurality of groove portions are formed in a length direction on a side surface on a side corresponding to a long side of the rectangular shape.

4. The housing of the semiconductor module according to claim 1 or 2, wherein a thickness of the first gate portion is 1 / 100 or more and 1 / 10 or less of a width of the first gate portion.

5. The housing of the semiconductor module according to claim 1 or 2, wherein the resin is formed of a polyamide resin to which a filler is added.

6. The housing of the semiconductor module according to claim 1 or 2, wherein a single second gate portion that is an outlet of the resin is further provided on a side surface on the one end side of the rectangular shape, and the second gate portion has a flat shape that is longer in a width direction of the housing.

7. The housing of the semiconductor module according to claim 6, wherein the second gate portion is provided at a position that is symmetrical with respect to the first gate portion.

8. A manufacturing method of a housing of a semiconductor module that is the housing of the semiconductor module according to any one of claims 1 to 7, wherein the manufacturing method of the housing of the semiconductor module includes the following steps: filling a resin into a mold through the first gate portion; and removing a resin flow path portion that is connected to the housing, the resin flow path portion having a flow passage portion that is connected to the first gate portion to form a passage of the resin, the flow passage portion having a thin plate shape that is longer in a width direction of the housing, and being inclined so as to decrease in thickness toward the first gate portion side.

9. The manufacturing method of the housing of the semiconductor module according to claim 8, wherein an inclination angle of the flow passage portion is 10 degrees or more and 30 degrees or less.

10. The manufacturing method of the housing of the semiconductor module according to claim 8 or 9, wherein a single second gate portion that is an outlet of the resin is provided on a side surface on the one end side of the rectangular shape, the second gate portion has a flat shape that is longer in a width direction of the housing. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The resin flow path portion includes another runner portion that is connected to the second gate portion to form a passage of the resin, The other runner portion has a thin plate shape that is longer in the width direction of the housing, is inclined so that the thickness decreases toward the second gate portion side, and is shorter than the runner portion.

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