Semiconductor equipment
The semiconductor device design with a stepped inner peripheral opening and storage portion for adhesive containment addresses adhesive overflow, ensuring effective adhesion without size increase, maintaining cleanliness and adhesion strength.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- FUJI ELECTRIC CO LTD
- Filing Date
- 2021-12-14
- Publication Date
- 2026-06-23
Smart Images
Figure 0007877672000001 
Figure 0007877672000002 
Figure 0007877672000003
Abstract
Description
Technical Field
[0001] The present invention relates to a semiconductor device.
Background Art
[0002] The semiconductor device includes a power device and is used as a power conversion device. The power device is, for example, an IGBT (Insulated Gate Bipolar Transistor) or a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor). Further, the semiconductor device includes a semiconductor chip including a power device, a case for housing the semiconductor chip, and a lid portion disposed at an opening of the case and covering the semiconductor chip. The lid portion is fixed to the opening of the case by an adhesive member.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, the adhesive member used for fixing the lid portion to the case may protrude from the opening of the case. For example, when a sufficient application area for the adhesive member cannot be secured on the case, the adhesive member protrudes. When the adhesive member protrudes, the adhesive member is wasted. Further, when the protruding adhesive member adheres to the lid portion and the case, the semiconductor device becomes dirty and the aesthetic property deteriorates. Further, the protruding adhesive member may also stain the periphery of the semiconductor device. On the other hand, in order to prevent the protrusion of the adhesive member, when securing an application area for the adhesive member on the case, it is necessary to increase the size of the case, leading to an increase in the size of the semiconductor device.
[0005] This invention has been made in view of the above points, and aims to provide a semiconductor device in which the protrusion of adhesive members is prevented while suppressing an increase in size. [Means for solving the problem]
[0006] According to one aspect of the present invention, the present invention comprises a semiconductor element, a case having a frame portion that forms a frame shape in plan view and includes an inner peripheral opening that surrounds the periphery of a storage area in which the semiconductor element is housed, and a lid portion that is flat and covers the upper part of the storage area, wherein the inner peripheral opening has a stepped portion that is lower than the front surface of the frame portion and has a stepped support surface that is substantially parallel to the front surface of the frame portion, the outer surface surrounding the lid portion is joined to the stepped portion by an adhesive member, the bottom surface of the lid portion is substantially parallel to the stepped support surface, and a storage portion is formed on the front surface of the lid portion, extending inward from the outer surface and including a storage surface that is lower than the front surface of the lid portion. The storage portion is formed on a part of the outer periphery of the lid, and in a plan view, the storage portion is formed in the center of at least one pair of opposing sides of the outer periphery of the front surface of the lid. Semiconductor equipment is provided. Furthermore, a semiconductor device is provided comprising: a semiconductor element; a case comprising a frame portion having a frame shape in plan view and including an inner peripheral opening that surrounds the periphery of a storage area in which the semiconductor element is housed; and a lid portion having a flat plate shape that covers the upper part of the storage area, wherein the inner peripheral opening is lower than the front surface of the frame portion and has a stepped portion having a stepped support surface substantially parallel to the front surface of the frame portion; the outer surface surrounding the lid portion is joined to the stepped portion by an adhesive member; the bottom surface of the lid portion is substantially parallel to the stepped support surface; and a storage portion is formed on the front surface of the lid portion, extending inward from the outer surface, and including a storage surface lower than the front surface of the lid portion; the stepped portion is formed continuously around the entire circumference of the inner peripheral opening, and the storage portion is provided inside the stepped portion. Furthermore, a semiconductor device is provided, comprising: a semiconductor element; a case comprising a frame portion having a frame shape in plan view and including an inner peripheral opening that surrounds the periphery of a storage area in which the semiconductor element is housed; and a lid portion having a flat plate shape that covers the upper part of the storage area, wherein the inner peripheral opening has a stepped portion formed thereon that is lower than the front surface of the frame portion and has a stepped support surface that is substantially parallel to the front surface of the frame portion; the outer surface surrounding the lid portion is joined to the stepped portion by an adhesive member; the bottom surface of the lid portion is substantially parallel to the stepped support surface; and a storage portion is formed on the front surface of the lid portion, extending inward from the outer surface and including a storage surface that is lower than the front surface of the lid portion, the storage portion is provided inside the stepped portion; and the case further comprises an external connection terminal integrally molded with the frame portion, one of which extends vertically upward from the front surface of the frame portion and the other extending into the storage area. [Effects of the Invention]
[0007] According to the disclosed technology, semiconductor devices can be made larger while preventing the adhesive material from overflowing. [Brief explanation of the drawing]
[0008] [Figure 1] This is a diagram showing a semiconductor device according to the first embodiment. [Figure 2] This is a plan view of the semiconductor device according to the second embodiment. [Figure 3] This is a plan view of the interior of the semiconductor device according to the second embodiment. [Figure 4] This is a cross-sectional view of a semiconductor device according to a second embodiment. [Figure 5] This is a plan view of the mounting location between the lid and case of the semiconductor device according to the second embodiment. [Figure 6] This is a cross-sectional view of the mounting location between the lid and case of the semiconductor device according to the second embodiment. [Figure 7] This is a cross-sectional view of the mounting location between the lid and case of the semiconductor device in Modification 2-1 of the second embodiment. [Figure 8] This is a plan view of the mounting location between the lid and case of the semiconductor device in Modification 2-2 of the second embodiment. [Figure 9] This is a plan view of the semiconductor device according to the third embodiment. [Figure 10] This is a plan view of the interior of the semiconductor device according to the third embodiment. [Figure 11] This is a cross-sectional view of a semiconductor device according to a third embodiment. [Modes for carrying out the invention]
[0009] The embodiments will be described below with reference to the drawings. In the following description, "front surface" and "top surface" refer to the surfaces of the semiconductor devices 1, 10, and 10a in Figures 1, 2, and 9 that face in the +Z direction. Similarly, "top" refers to the direction in the +Z direction of the semiconductor devices 1, 10, and 10a in Figures 1, 2, and 9. "Back surface" and "bottom surface" refer to the surfaces of the semiconductor devices 1, 10, and 10a in Figures 1, 2, and 9 that face in the -Z direction. Similarly, "bottom" refers to the direction in the -Z direction of the semiconductor devices 1, 10, and 10a in Figures 1, 2, and 9. "Side surface" refers to the surfaces of the semiconductor devices 1, 10, and 10a in Figures 1, 2, and 9 that face in the +Z direction. orThis refers to the surface connecting to the "bottom surface". For example, "side surface" refers to the surface facing the ±X and ±Y directions in semiconductor devices 1, 10, and 10a in Figures 1, 2, and 9. This directionality is used in all drawings. "Front surface," "top surface," "upper," "back surface," "bottom surface," "down," and "side surface" are merely convenient expressions to specify relative positional relationships and do not limit the technical concept of the present invention. For example, "upper" and "down" do not necessarily mean the vertical direction relative to the ground. In other words, the directions of "upper" and "down" are not limited to the direction of gravity. Also, in the following explanation, "main component" refers to a case where it contains 80 vol% or more. Also, in the following, "approximately parallel" means that the angle between two objects is in the range of 170° or more and 190° or less. "Approximately right angle" means that the angle between two objects is in the range of 85° or more and 95° or less.
[0010] [First Embodiment] The semiconductor device 1 of the first embodiment will be described with reference to Figure 1. Figure 1 is a diagram showing the semiconductor device of the first embodiment. The middle section of Figure 1 shows a plan view of the semiconductor device 1 shown at the top of Figure 1. The upper section of Figure 1 shows a cross-sectional view of the semiconductor device 1 shown in the middle section of Figure 1 along the dashed line Y1-Y1. The lower section of Figure 1 shows a cross-sectional view of the semiconductor device 1 shown in the middle section of Figure 1 along the dashed line Y2-Y2.
[0011] The semiconductor device 1 shown in Figure 1 includes a case 2 and a lid 3, and can house a semiconductor element. The case 2 comprises a frame portion 2a and a bottom portion 2d, which form a frame shape in plan view. The frame portion 2a surrounds the periphery of an open storage area 2c in which the semiconductor element is housed. The semiconductor element is not shown in this figure. The storage area 2c is rectangular in plan view. Therefore, the frame portion 2a surrounds the open inner periphery of the storage area 2c on all four sides. 2e It is equipped with the following. Furthermore, the frame portion 2a has an inner circumference portion of the opening on the front side. 2eIt includes a stepped portion 2b formed along it. The case 2 may include not only semiconductor elements but also components of the semiconductor device 1. The components are, for example, an insulating circuit board on which semiconductor elements are arranged, electronic components, and a printed circuit board. The frame portion 2a has a rectangular shape in plan view, and its storage area 2c and the inner peripheral portion of its opening 2e also have a rectangular shape. Here, the rectangular shape is a rectangular shape, but it may also be a square shape.
[0012] The stepped portion 2b Frame 2a of the inner peripheral portion of the opening 2e is continuously formed in an annular shape along it. The stepped portion 2b includes a stepped inner peripheral surface 2b1 and a stepped support surface 2b2. The stepped inner peripheral surface 2b1 faces the center side of the frame portion 2a in plan view and is formed on the long side and the short side of the inner peripheral portion of the opening 2e respectively. That is, the stepped inner peripheral surface 2b1 is formed parallel to the Z-X plane on the opposing long side of the inner peripheral portion of the opening 2e . The stepped inner peripheral surface 2b1 is formed parallel to the Z-Y plane on the opposing short side of the inner peripheral portion of the opening 2e . The height of the stepped inner peripheral surface 2b1 is determined by the thickness of the lid portion 3. In FIG. 1, the case where the height of the stepped inner peripheral surface 2b1 is the same as the thickness of the lid portion 3 is shown. The stepped support surface 2b2 is orthogonal to the stepped inner peripheral surface 2b1 and faces in the +Z direction (parallel to the X-Y plane) and is continuously formed in an annular shape along the inner peripheral portion of the opening <0The bottom portion 2d is formed on the back side of the frame portion 2a. In Figure 1, the bottom portion 2d and the back side of the frame portion 2a are on the same plane. The bottom portion 2d closes the storage area 2c from the back. In Figure 1, the bottom portion 2d is shown as being integrally formed with the frame portion 2a. The bottom portion 2d may not be integrally formed with the frame portion 2a but may be formed separately. Such a bottom portion 2d may be, for example, a metal base substrate.
[0014] The lid portion 3 is flat and rectangular in plan view. This rectangular shape corresponds to the opening of the case 2. The lid portion 3 includes outer surfaces 3c2 that surround each of its four sides (opposite long sides and opposite short sides). This lid portion 3 is joined to the stepped portion 2b of the frame portion 2a of the case 2 by adhesive members 4. As a result, the storage area 2c of the case 2 is enclosed by the lid portion 3, the frame portion 2a, and the bottom portion 2d. As will be described later, the lid portion 3 is attached to the stepped portion 2b of the frame portion 2a of the case 2. In this case, the bottom surface 3b of the lid portion 3 is entirely on the same plane. For example, the outer edge of the bottom surface 3b of the lid portion 3 is supported by the stepped support surface 2b2 of the stepped portion 2b. The outer edge of the bottom surface 3b of the lid portion 3 and the bottom surface 3b other than the outer edge are on the same plane. The bottom surface 3b of the lid 3 does not include any chamfered or recessed portions.
[0015] The lid portion 3 further has a storage portion 3c formed therein. The storage portion 3c is formed on the outer periphery of the front surface 3a of the lid portion 3. In plan view, the storage portion 3c includes a region that is lower than the front surface 3a of the lid portion 3, at least on the outer surface 3c2 side, extending inward (towards the center of the lid portion 3) from the outer surface 3c2 of the front surface 3a of the lid portion 3. The storage portion 3c shown in Figure 1 includes a storage surface 3c1 as such a lower region. The storage surface 3c1 is lower than the front surface 3a of the lid portion 3 and is parallel to the front surface 3a. Connected toThe lid portion 3 includes inner surfaces 3c3 and 3c4 parallel to the long side. The inner surfaces 3c3 and 3c4 connect the storage surface 3c1 and the outer surface 3a. As shown in the upper part of Figure 1, the surface connecting the storage surface 3c1 and the outer surface 3a of the lid portion 3 is perpendicular to both the outer surface 3a and the storage surface 3c1 of the lid portion 3. In Figure 1, such storage portions 3c are formed in the center of the long and short sides of the outer surface 3a of the lid portion 3. The storage portions 3c may also be formed in a continuous annular shape along the outer circumference of the outer surface 3a.
[0016] Such a lid portion 3 is attached to the stepped portion 2b of the case 2, and adhesive member 4 is applied to the gap G between the outer surface 3c2 of the lid portion 3 and the inner circumferential surface 2b1 of the stepped portion 2b of the case 2, and spreads into the gap G. At this time, the adhesive member 4 enters and is stored in the storage portion 3c of the lid portion 3. Therefore, the overflow of the adhesive member 4 from the gap G is suppressed.
[0017] Therefore, the semiconductor device 1 described above includes a case 2 and a lid 3 for housing the semiconductor element. The case 2 has a frame shape in plan view and surrounds the periphery of the housing area 2c in which the semiconductor element is housed, with an open inner periphery. 2e It includes a frame portion 2a. The lid portion 3 is flat and covers the storage area 2c. Opening inner circumference 2e The lid portion 3 has a stepped portion 2b which is lower than the front surface of the frame portion 2a and has a stepped support surface 2b2 which is substantially parallel to the front surface of the frame portion 2a. In this case, the outer surface 3c2 surrounding the lid portion 3 is joined to the stepped portion 2b by an adhesive member 4, the bottom surface 3b of the lid portion 3 is substantially parallel to the stepped support surface 2b2, and a storage portion 3c is formed on the front surface 3a of the lid portion 3, including a storage surface 3c1 which is lower than the front surface 3a of the lid portion 3, extending inward from the outer surface 3c2.
[0018] Adhesive member 4 is applied to the gap G between the outer surface 3c2 of the lid 3 and the inner circumferential surface 2b1 of the stepped portion 2b of the case 2, and spreads into the gap G. At this time, the adhesive member 4 enters and is stored in the storage portion 3c of the lid 3. Therefore, without increasing the size of the semiconductor device 1, the overflow of adhesive member 4 from the gap G is suppressed, preventing waste of adhesive member 4. By suppressing the overflow of adhesive member 4, adhesion of adhesive member 4 to the lid 3 and case 2 is suppressed, preventing contamination of the semiconductor device 1. In addition, the adhesive member 4 enters the storage portion 3c along with the gap G. Therefore, the adhesive area of adhesive member 4 to the lid 3 increases compared to when there is no storage portion 3c. Consequently, the bonding force of the lid 3 to the case 2 via adhesive member 4 is improved.
[0019] [Second Embodiment] In the second embodiment, a more specific semiconductor device than the semiconductor device 1 of the first embodiment will be described using Figures 2 to 4. Figure 2 is a plan view of the semiconductor device of the second embodiment, and Figure 3 is a plan view of the interior of the semiconductor device of the second embodiment. Figure 4 is a cross-sectional view of the semiconductor device of the second embodiment. Note that Figure 3 is a plan view of the semiconductor device 10 with the lid 75 and sealing member 95 removed. Figure 4 is a cross-sectional view at the dashed-dotted line XX in Figure 2. The position of the dashed-dotted line XX in Figure 2 corresponds to the position of the dashed-dotted line XX in Figure 3.
[0020] The semiconductor device 10 includes a semiconductor unit 30, a printed circuit board 40, a case 50 and a lid 75 that house the semiconductor unit 30 and the printed circuit board 40. The semiconductor unit 30 includes a main circuit board 20 and first and second semiconductor chips 31 and 32 mounted on the main circuit board 20. The semiconductor unit 30 has six sets of the first and second semiconductor chips 31 and 32. The main circuit board 20 includes an insulating plate 21, a circuit pattern 22, and a metal base substrate 23. The main circuit board 20 and the printed circuit board 40 are arranged adjacent to each other in a plan view.
[0021] The insulating plate 21 can be, for example, an organic insulating layer or a ceramic substrate. The organic insulating layer is composed of a combination of a resin with low thermal resistance and a material with high thermal conductivity. The former resin is, for example, an epoxy resin or a liquid crystal polymer insulating resin. The latter material is, for example, boron nitride, aluminum oxide, or silicon oxide.
[0022] The ceramic substrate is made of ceramics with good thermal conductivity. The ceramics are composed of materials primarily consisting of, for example, aluminum oxide, aluminum nitride, and silicon nitride. Furthermore, such an insulating plate 21 has a rectangular shape when viewed from above. The thickness of the insulating plate 21 is between 0.5 mm and 2.0 mm.
[0023] The circuit pattern 22 constitutes a predetermined circuit. The circuit pattern 22 is formed on the front surface of the insulating plate 21, for example, as shown in Figure 3. First, one circuit pattern 22 formed on the left side of the front surface of the insulating plate 21 has three sets of first and second semiconductor chips 31 and 32 mounted on it. Three circuit patterns 22 formed along the +X direction to the right of the front surface of the insulating plate 21 each have one set of first and second semiconductor chips 31 and 32 mounted on them. One circuit pattern 22 formed in the lower right corner of the front surface of the insulating plate 21 has nothing mounted on it.
[0024] Furthermore, in these circuit patterns 22, one region where the first and second semiconductor chips 31 and 32 are arranged is positioned along the upper part of the insulating plate 21 in Figure 3, and the other region extends downward in Figure 3 of the insulating plate 21. Note that the circuit patterns 22 only show the case where a total of six sets of first and second semiconductor chips 31 and 32 are provided. The number of first and second semiconductor chips 31 and 32 is not limited to six sets, and the number of sets and the number of circuit patterns 22 can be determined according to the specifications of the semiconductor device 10, etc. Multiple circuit patterns 22 are formed on the front surface of the insulating plate 21. In addition, the circuit patterns 22 are mainly composed of a metal with excellent conductivity. Such metals are, for example, silver, copper, nickel, or an alloy containing at least one of these. The thickness of the circuit patterns 22 is Preferably, the thickness is 0.1 mm or more and 1.0 mm or less, and more preferably 0.2 mm or more and 0.5 mm or less. The surface of the circuit pattern 22 may be plated to improve its corrosion resistance. Examples of plating materials used include nickel, nickel-phosphorus alloy, and nickel-boron alloy. Such a circuit pattern 22 is formed by etching a conductive plate or foil formed on one side of the insulating plate 21, or by bonding a conductive plate to one side of the insulating plate 21. 。
[0025] The metal base substrate 23 is mainly composed of a metal with excellent thermal conductivity. The corners of the metal base substrate 23 may also be chamfered (R-chamfering or C-chamfering). Such metals include, for example, aluminum, iron, silver, copper, or alloys containing at least one of these. The metal base substrate 23 has a rectangular shape in plan view and corresponds to the main circuit area 61 and the control circuit area 62 (described later) at the bottom 60 of the case 50. The thickness of the metal base substrate 23 is 0.5 mm or more and 2.0 mm or less. Plating may be performed on the surface of the metal base substrate 23 to improve corrosion resistance. Examples of plating materials used include nickel, nickel-phosphorus alloys, and nickel-boron alloys.
[0026] Furthermore, if the insulating plate 21 is a ceramic substrate and the metal base substrate 23 is a metal foil, DCB (Direct Copper Bonding) substrates and AMB (Active Metal Brazed) substrates may be used for the circuit pattern 22, insulating plate 21, and metal base substrate 23. Note that the shape, placement position, and number of circuit patterns 22, and the placement position and number of first and second semiconductor chips 31 and 32 in a semiconductor unit 30 having such a configuration are examples and are not limited to Figures 2 to 4; they may be appropriately determined through design, etc.
[0027] The first and second semiconductor chips 31 and 32 are power semiconductor chips composed of silicon, silicon carbide, or gallium nitride. The first semiconductor chip 31 includes a switching element. Examples of switching elements include IGBTs and power MOSFETs. When the first semiconductor chip 31 is an IGBT, the collector electrode is placed on the back surface as the main electrode, and on the front surface, As a control electrode It is equipped with an emitter electrode as the gate electrode and a main electrode, respectively. When the first semiconductor chip 31 is a power MOSFET, the drain electrode is provided on the back surface as the main electrode, and on the front surface, As a control electrode The first semiconductor chip 31 is provided with a gate electrode and a source electrode as the main electrode. The back surface of the first semiconductor chip 31 is joined to the circuit pattern 22 by a bonding member (not shown). In this embodiment, the bonding member is solder or a metal sintered body. The solder is made of lead-free solder mainly composed of a predetermined alloy. The predetermined alloy is, for example, at least one of the following alloys: a tin-silver alloy, a tin-zinc alloy, or a tin-antimony alloy. The solder may also contain additives such as copper, bismuth, indium, nickel, germanium, cobalt, or silicon. For the metal sintered body, for example, aluminum or copper can be used.
[0028] The second semiconductor chip 32 includes a diode element. Examples of diode elements include FWDs (Free Wheeling Diodes) such as SBDs (Schottky Barrier Diodes) and PiN (P-intrinsic-N) diodes. Such a second semiconductor chip 32 has an output electrode (cathode electrode) as the main electrode on its back surface and an input electrode (anode electrode) as the main electrode on its front surface. The back surface of the above-mentioned second semiconductor chip 32 is bonded to the circuit pattern 22 by a bonding member.
[0029] The thickness of these first and second semiconductor chips 31 and 32 is, for example, 180 μm or more and 220 μm or less, with an average of about 200 μm. Instead of the first and second semiconductor chips 31 and 32, an RC (Reverse-Conducting)-IGBT, which combines the functions of IGBT and FWD, may be used.
[0030] The printed circuit board 40 is positioned adjacent to the main circuit board 20, which is arranged horizontally to the bottom surface of the case 50 via an adhesive member 60a, and is located above the main circuit board 20 in the +Z direction. Such a printed circuit board 40 comprises an insulating plate and a plurality of upper circuit patterns formed on the front surface of the insulating plate. The printed circuit board 40 may also have a plurality of lower circuit patterns on the back surface of the insulating plate.
[0031] An insulating board is a flat plate made of an insulating material. Such a material is obtained by immersing a substrate in resin. Examples of substrates include paper, glass cloth, and glass nonwoven fabric. Examples of resins include phenolic resin, epoxy resin, and polyimide resin. Specific examples of insulating boards include paper phenolic substrates, paper epoxy substrates, glass epoxy substrates, glass polyimide substrates, and glass composite substrates. Such insulating boards are also rectangular in plan view. The corners of the insulating board may be rounded (R-chamfered) or chamfered (C-chamfered).
[0032] The upper and lower circuit patterns are arranged in multiple layers and form a predetermined pattern shape to constitute a predetermined circuit. The upper and lower circuit patterns are made of a material with excellent conductivity. Such materials include, for example, silver, copper, nickel, or an alloy containing at least one of these. The surfaces of the upper and lower circuit patterns may be plated to improve corrosion resistance. Materials used in this plating process include, for example, nickel, nickel-phosphorus alloys, and nickel-boron alloys.
[0033] Such a printed circuit board 40 can be formed, for example, as follows: Metal foils are attached to the front and back surfaces of an insulating board, and a resist of a predetermined shape is printed on them. Using the printed resist as a mask, the metal foils on the front and back surfaces of the insulating board are etched to remove the remaining resist. This forms an upper circuit pattern and a lower circuit pattern on the front and back surfaces of the insulating board, respectively.
[0034] Furthermore, an integrated circuit (IC) 41 is provided as an electronic component on the printed circuit board 40 and is electrically connected to the upper circuit pattern. In this embodiment, as shown in Figure 3, the control IC 41 is electrically and mechanically connected to the gate electrode (control electrode) of the first semiconductor chip 31 by a bonding wire 43. The control IC 41 applies a control voltage to the first semiconductor chip 31 at predetermined timings. The bonding wire 43 used in this case is made of a material with excellent conductivity. For example, this material is made of gold, silver, copper, aluminum, or an alloy containing at least one of these. The diameter of the bonding wire 43 is, for example, 100 μm or more and 250 μm or less. In addition to the control IC 41, other necessary electronic components may be mounted on the printed circuit board 40. Examples of such electronic components include thermistors, capacitors, resistors, current sensors, and temperature sensors.
[0035] Furthermore, within the main circuit board 20, the first and second semiconductor chips 31 and 32, and the second semiconductor chip 32 and the circuit pattern 22 are electrically and mechanically connected by bonding wires 33. The circuit pattern 22 of the printed circuit board 40 and the main circuit board 20 are also electrically and mechanically connected by bonding wires 33. The bonding wires 33 used here are also made of a material with excellent conductivity as described. The diameter of the bonding wires 33 is, for example, 400 μm or more and 1.00 mm or less.
[0036] Next, we will describe case 50. Case 50 includes a bottom portion 60 and a frame portion 70 integrally formed surrounding the periphery of the bottom portion 60. Furthermore, case 50 includes main current connection terminals 80a to 80e and a control terminal 90. In the following description, unless otherwise specified, the main current connection terminals 80a to 80e will be referred to as main current connection terminal 80.
[0037] Such a case 50 is molded from a thermoplastic resin. Examples of thermoplastic resins include polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, polybutylene succinate (PBS) resin, polyamide (PA) resin, or acrylonitrile butadiene styrene (ABS) resin. The case 50 is molded using such a thermoplastic resin by injection molding, including the main current connection terminal 80 and the control terminal 90.
[0038] The bottom portion 60 has a rectangular shape in plan view. The bottom portion 60 has a main circuit area 61 and a control circuit area 62 set on its front surface, the bottom surface. The main circuit area 61 on the bottom surface is open. The main circuit board 20 is placed in the main circuit area 61, and the printed circuit board 40 is placed in the control circuit area 62. That is, as shown in Figure 3, the main circuit area 61 and the control circuit area 62 are set adjacent to each other on the front surface of the bottom portion 60 in plan view. A taper may be formed on the back side of the opening edge of the opened main circuit area 61. Furthermore, the back of the bottom portion 60 The faceA rear opening 63 is also formed. The rear opening 63 penetrates to the area corresponding to the main circuit region 61. The semiconductor unit 30 is attached to the bottom 60 from its rear side. That is, the metal base substrate 23 is attached to the rear opening 63, and the main circuit board 20 is exposed through the opened main circuit region 61. The metal base substrate 23 is attached to the rear opening 63 of the bottom 60 by an adhesive member (not shown). The rear surface of the metal base substrate 23 attached in this way protrudes outward (towards the bottom in Figure 4) from the rear surface of the bottom 60. Alternatively, the rear surface of the metal base substrate 23 may be on the same plane as the rear surface of the bottom 60.
[0039] The adhesive used to join the metal base substrate 23 to the back surface opening 63 of the bottom portion 60 is, for example, a thermosetting resin adhesive or an organic adhesive. Thermosetting resin adhesives mainly consist of epoxy resin or phenolic resin. Organic adhesives are elastomer adhesives mainly consisting of silicone rubber or chloroprene rubber. Preferably, epoxy resin or silicone rubber is the main component.
[0040] The control circuit area 62 is located on the front surface of the bottom portion 60, adjacent to the side wall portion 71a of the main circuit area 61, opposite to it. The printed circuit board 40 is placed in the control circuit area 62 on the bottom surface of the bottom portion 60 via the aforementioned bonding member.
[0041] The frame portion 70 has a frame shape when viewed from above. This frame portion 70 includes side walls 71a, 71b, 71c, and 71d that surround the bottom portion 60 on all four sides. The side walls 71a, 71b, 71c, and 71d also surround the storage area 72. It includes the inner perimeter of the opening. In Figure 4, the inner perimeter of the opening 74a and 74c, which are included in the side wall portions 71a and 71c, are shown. The inner perimeter of the opening included in the side wall portions 71b and 71d is not shown, but it is provided in the same way as the inner perimeter of the opening 74a and 74c. The heights of the side walls 71a, 71b, 71c, and 71d are all the same. The side walls 71a and 71c are provided on the long sides of the bottom 60, respectively. Main current connection terminals 80a to 80e are integrally molded along the side wall 71a and the bottom 60, respectively. Control terminals 90 are integrally molded along the side wall 71c and the bottom 60, respectively.
[0042] Furthermore, stepped portions 72a, 72b, 72c, and 72d are formed along the inner circumference of the front side of the side wall portions 71a, 71b, 71c, and 71d, respectively. Note that the stepped portions 72b and 72d are formed on the side wall portions 71b and 71d, respectively, straddling the fastening holes 73, which will be described later. Protrusions 72a3, 72b3, 72c3, and 72d3 are formed on the stepped portions 72a, 72b, 72c, and 72d, respectively. Details of these stepped portions 72a, 72b, 72c, and 72d will be described later.
[0043] The main current connection terminal 80 has an L-shape when viewed from the side, as shown in Figure 4. Specifically, the main current connection terminal 80 is formed from a plate-shaped member bent into an L-shape. The main current connection terminal 80 has, for example, a thickness of 100 μm or more and less than 1.0 mm, and a width of 1.0 mm or more and 10 mm or less. The main current connection terminal 80a has an external connection part 81a and an internal connection part 82a. One end of the external connection part 81a extends upward from the upper surface of the side wall part 71a, and the other end is connected to the internal connection part 82a within the side wall part 71a and the bottom part 60. one end It is integrally connected to the bottom 60. The other end of the internal connection part 82a is exposed from the terminal step portion 71e of the bottom 60. The other end of the internal connection part 82a is electrically and mechanically connected to the circuit pattern 22 by bonding wire 33. Similarly, the main current connection terminals 80b to 80e have external connection parts 81b to 81e and internal connection parts 82b to 82e. One end of the external connection parts 81b to 81e extends upward from the upper surface of the side wall portion 71a, and the other end is connected to the internal connection parts 82b to 82e within the side wall portion 71a and the bottom 60. one endThey are integrally connected to the main current connection terminals 80a to 80e. The other ends of the internal connection parts 82b to 82e are exposed from the bottom 60. The other ends of the internal connection parts 82b to 82e are electrically and mechanically connected to the circuit pattern 22 by bonding wires 33. The external connection parts 81a to 81e and the internal connection parts 82a to 82e of the main current connection terminals 80a to 80e will be described as external connection part 81 and internal connection part 82, respectively, as shown in Figure 4, unless otherwise specified. The main current connection terminal 80 is made of a material with excellent conductivity. Such materials include, for example, copper, aluminum, nickel, or an alloy containing at least one of these. The surface of the main current connection terminal 80 may be plated. The material used for this plating is, for example, nickel or a nickel alloy.
[0044] The control terminal 90 has an L-shape when viewed from the side, as shown in Figure 4. Specifically, the control terminal 90 is formed from a columnar member bent into an L-shape. The control terminal 90 has an external terminal portion 91 and an internal terminal portion 92. One end of the external terminal portion 91 extends upward from the upper surface of the side wall portion 71c, and the other end is within the side wall portion 71c and the bottom portion 60 and the internal terminal portion 92 one end It is integrally connected to the control terminal 90. The other end of the internal terminal portion 92 is exposed from the terminal step portion 71f of the bottom portion 60. The other end of the internal terminal portion 92 is electrically and mechanically connected to the printed circuit board 40 by bonding wires 33. In this way, the internal terminal portion 92 of the control terminal 90 is electrically connected to the upper or lower circuit pattern of the printed circuit board 40. When a control signal is input from the outside to the external terminal portion 91 of the control terminal 90, the internal terminal portion 92 of the control terminal 90 and the printed circuit board 40 become conductive. Then, as a control signal is input from the printed circuit board 40 to the control IC 41, a control signal is output from the control IC 41 to the gate electrode of the first semiconductor chip 31 via bonding wires 43.
[0045] The control terminal 90 is made of a material with excellent conductivity. Such materials include, for example, copper, aluminum, nickel, or an alloy containing at least one of these. The surface of the control terminal 90 may be plated. The material used for this plating is, for example, nickel or a nickel alloy.
[0046] The side walls 71b and 71d are provided on the short sides of the bottom 60, respectively. The side walls 71b and 71d are provided with fastening holes 73 for attaching a cooler to the back surface of the semiconductor device 10. A cooler (not shown) may be attached to the back surface of the semiconductor device 10 (the back surface of the metal base substrate 23), and the cooler may be fastened by passing screws through the fastening holes 73. In this case, the cooler can be attached to the back surface of the semiconductor device 10 via solder, silver solder, thermal grease, or a thermal sheet to improve heat dissipation. In this case, the cooler may be made mainly of a metal with excellent thermal conductivity. Examples of such metals include aluminum, iron, silver, copper, or alloys containing at least one of these. In addition, a heat sink and a water cooling device may be used as the cooler. The metal base substrate 23 may also be integrated with such a cooler.
[0047] A sealing member 95 is filled into the storage area 72 of the case 50 containing such parts, and the inside of the storage area 72 is sealed by the sealing member 95. The sealing member 95 contains a thermosetting resin and an inorganic filler contained in the thermosetting resin. The thermosetting resin mainly consists of at least one selected from the group including, for example, epoxy resin, phenolic resin, and melamine resin. Preferably, the thermosetting resin is mainly composed of epoxy resin. In addition, an inorganic material mainly composed of silicon dioxide is used as the inorganic filler. Furthermore, high flame retardancy can be maintained without incorporating flame retardants such as halogen-based, antimony-based, or metal hydroxide-based agents. The inorganic filler is 70 vol% or more and 90 vol% or less of the total sealing material.
[0048] The lid portion 75 is flat and, in plan view, is approximately rectangular. Specifically, the shape of the lid portion 75 in plan view corresponds to the opening shape of the storage area 72. The lid portion 75 is surrounded on all four sides by outer surfaces 75a2, 75b2, 75c2, and 75d2. The outer surfaces 75a2 and 75c2 correspond to the long sides of the lid portion 75 and are parallel to the ±X direction. The outer surfaces 75b2 and 75d2 correspond to the short sides of the lid portion 75 and are parallel to the ±Y direction. However, the centers of the outer surfaces 75b2 and 75d2 are recessed towards the center in plan view due to the fastening holes 73. Furthermore, as will be described later, when the lid portion 75 is attached to the stepped portions 72a, 72b, 72c, 72d of the case 50, the outer surfaces 75a2, 75b2, 75c2, 75d2 become the inner circumferential surfaces of the steps (inner circumferential surfaces of the steps 72 in Figure 6) c It is approximately parallel to (see 1). The thickness of the lid portion 75 is, for example, 1.8 mm or more and 2.2 mm or less, and may be 2.0 mm. The lid portion 75 has a positioning member 76 and a storage portion 75c formed on its front surface 75a. In addition, a fixing hole is formed on the back surface 75b of the lid portion 75 (see fixing hole 75b1 in Figure 6). The fixing hole will be described later.
[0049] The positioning members 76 are formed, for example, in pairs on the short side of the front surface 75a of the lid portion 75. The positioning members 76 are cylindrical in shape, for example, such that their cross-section decreases in diameter as they move in the +Z direction. A printed circuit board is separately attached to the positioning members 76. Note that the location of the positioning members 76 is just one example.
[0050] Multiple storage compartments 75c are formed on the outer circumference of the opposing long sides of the front surface 75a of the lid 75. In this case, four storage compartments 75c are formed on each of the opposing long sides. The location and number of storage compartments 75c are just examples; they can be formed anywhere on the outer circumference of the lid 75, and any number of them may be formed.
[0051] Furthermore, when the case 50 is fastened at any point using the fastening holes 73, some parts may bend and warp. If the case 50 warps, even if the lid portion 75 is attached to the stepped portions 72a, 72b, 72c, and 72d with adhesive members 96, there is a risk that it may detach from the frame portion 70 at the warped portion. Therefore, it is preferable that the storage portion 75c be formed on the outer circumference of the lid portion 75 corresponding to the area of the frame portion 70 that is prone to warping. The location of this warping depends on where the fastening holes 73 are formed on the case 50. For example, in this embodiment, the frame portion 70 is rectangular in plan view, and fastening holes 73 are provided in the center of each short side. In this case, it is conceivable that the center line passing through the center of the opposing long sides of the case 50 will warp convexly in the +Z direction. For this reason, it is preferable that the storage portion 75c be formed on the outer circumference of the long side of the lid portion 75.
[0052] Furthermore, in this embodiment, a positioning member 76 is formed on the short side of the lid portion 75. It is preferable to avoid forming the storage portion 75c near the positioning member 76. When a printed circuit board is attached to the positioning member 76, stress (in the -Z direction) corresponding to the attachment of the printed circuit board is generated near the connection point of the positioning member 76 to the lid portion 75. If the storage portion 75c is formed near this point, the strength of this area will decrease because the storage portion 75c is thinner than other parts, and in some cases, damage may occur. For this reason, the formation of the storage portion 75c on the short side of the lid portion 75 where the positioning member 76 is provided should be avoided. Note that the vicinity in this case may be the range from the positioning member 76 to a position separated by a length corresponding to the depth of the stepped portions 72b and 72d.
[0053] Such a lid portion 75 is fixed to the stepped portions 72a, 72b, 72c, and 72d of the frame portion 70 by adhesive members 96. The fixed lid portion 75 covers the sealing member 95 inside the storage area 72.
[0054] Next, the mounting location of the lid 75 to the case 50 (the area enclosed by the dashed lines in Figures 2 and 4) will be explained using Figures 5 and 6. Figure 5 is a plan view of the mounting location between the lid and case of the semiconductor device in the second embodiment, and Figure 6 is a cross-sectional view of the mounting location between the lid and case of the semiconductor device in the second embodiment. 5 is ,figure 2 Enlarge the area enclosed by the dashed line. Show They are doing it. Figure 6 is a cross-sectional view along the dashed line XX in Figure 5. Furthermore, in Figures 5 and 6, the side wall portion 71 c Stepped portion 72 formed c The storage portion 75c of the lid portion 75 attached to the side wall portion 71 will be described. a Stepped portion 72 formed a And the storage portion 75c of the lid portion 75 is the same as in this case, although it is not shown in the figure. Also, the stepped portions 72b and 72d formed on the side wall portions 71b and 71d are also the same as the side wall portion 71 c Stepped portion 72 formed c It has a similar configuration to the previous one.
[0055] Side wall portion 71 of frame portion 70 c inner circumference of the opening on the front surface 74c The stepped section 72 continues all around. c A stepped portion 72 is formed. c The inner circumferential surface of the step 72 c 1 and step support surface 72 c 2 and projection 72 c It includes 3.
[0056] Step inner circumferential surface 72 c 1 is the side wall portion 71 facing the storage area 72 side in a plan view. c inner circumference of the opening on the front side 74c It is formed continuously along the step inner circumferential surface 72 c 1 is parallel to the ZX plane. Also, the inner circumferential surface 72 of the step c The height of 1 is approximately the same as the thickness (height) of the lid 75.
[0057] Step support surface 72 c 2 is the inner circumferential surface 72 of the step cThe side wall portion 71 is perpendicular to 1 and faces the +Z direction. c inner circumference of the opening 74c It is formed continuously along the step support surface 72 c The width of 2 (length in the +Y direction in Figure 6) may be a length that can support the lid portion 75. Step support surface 72c2 is the stepped portion 72 c When the lid portion 75 is attached, the stepped inner circumferential surface 72 c The gap G between 1 and the outer surface 75c2 of the lid 75 may be of a certain size. Such a gap G is, for example, 0.2 mm or more and 0.3 mm or less.
[0058] Projection 72 c 3 is the step support surface 72 c It is formed in 2 and extends vertically upward (+Z direction). Projection 72 c The height of 3 may be such that it does not protrude from the front surface 75a of the lid portion 75. In this embodiment, the projection 72 c The height of 3 indicates a height that does not penetrate the storage section 75c. On the other hand, projection 72 c 3 may be of a height that penetrates the storage surface 75c1 of the lid portion 75 but does not protrude from the storage portion 75c (front surface 75a). In this case, as will be described later, the adhesive member 96 stored in the storage portion 75c has a projection 72 that penetrates the storage surface 75c1 within the storage portion 75c. c It is joined to 3. This results in the stepped portion 72 c The bonding force of the lid portion 75 to the projection 72 can be improved. c 3 may have a circular or rectangular columnar shape in plan view. Protrusion 72 c 3 may be hemispherical. Protrusion 72 c 3 is the step support surface 72 c It is sufficient that it is formed in 2. In this embodiment, the projection 72 c 3 is a stepped support surface 72 corresponding to the storage portion 75c formed in the lid portion 75. c The example given is the case where it is formed at position 2.
[0059] The storage portion 75c formed in the lid portion 75 is formed on the outer periphery of the front surface 75a, extending inward from the outer surface 75c2 in a plan view. The storage portion 75c includes a storage surface 75c1 that includes at least a region on the outer surface 75c2 side that is lower than the front surface 75a, and inner surfaces 75c3 and 75c4 formed on both sides of the storage surface 75c1 in the ±X direction.
[0060] In this embodiment, the storage surface 75c1 of the storage section 75c is connected to the outer surface 75c2 and slopes upward from the outer surface 75c2 toward the front surface 75a. Therefore, the storage surface 75c1 includes a region on the outer surface 75c2 side that is lower than the front surface 75a. As previously described, this outer surface 75c2 is the inner circumferential surface 72 of the step c It is approximately parallel to 1. The height of the outer surface 75c2 corresponding to the storage section 75c is about half the thickness of the lid 75. If the height of the outer surface 75c2 corresponding to the storage section 75c is smaller than this, the strength of the storage section 75c will decrease, which may cause the storage section 75c to break and lead to damage to the lid 75. If the height of the outer surface 75c2 corresponding to the storage section 75c is larger than this, the volume of the storage section 75c will not exceed a certain level, resulting in insufficient storage of the adhesive member 96. If the storage amount is insufficient, it will be necessary to increase the number of storage sections 75c or to form the storage sections 75c so that the storage surface 75c1 has a sufficient area. This may increase the manufacturing cost of the storage section 75c.
[0061] The inner surfaces 75c3 and 75c4 connect the storage surface 75c1 and the outer surface 75a. The inner surfaces 75c3 and 75c4 are Z- Y The surfaces are parallel to each other. The connection points between the inner surfaces 75c3 and 75c4 and the storage surface 75c1 do not necessarily have to be perpendicular; they may be connected by a curved surface. Alternatively, the inner surfaces 75c3 and 75c4 may widen towards the outer surface 75a. Furthermore, the connection points between the storage surface 75c1 and the outer surface 75c2 do not necessarily have to be perpendicular; they may be connected by a curved surface.
[0062] Furthermore, fixing holes 75b1 are formed on the back surface 75b of the lid portion 75. The fixing holes 75b1 are located on the stepped portion 72 c When placed, the projection 72 c It is formed at the location corresponding to 3. The fixing hole 75b1 is the projection 72 c 3 should be shaped in such a way that it can be inserted, and the projection 72 c It is formed according to the shape of 3. The fixing hole 75b1 is formed by the projection 72 c Depending on the height of 3, it may be a through hole. In this embodiment, the case where the fixing hole 75b1 is not a through hole is given as an example.
[0063] Next, we will describe the attachment of the lid portion 75 to the case 50 (frame portion 70) and the application of the adhesive member 96. First, the lid portion 75 is attached to the stepped portions 72a, 72b, 72c, and 72d of the side wall portions 71a, 71b, 71c, and 71d of the frame portion 70.
[0064] After this, the stepped portions 72a, 72b, 72c, 72d of the side wall portions 71a, 71b, 71c, 71d and the lid portion 75 of The adhesive member 96 is poured into the gap G. The lid portion 75 is fixed to the stepped portions 72a, 72b, 72c, and 72d by the protrusions 72a3, 72b3, 72c3, and 72d3. As a result, the gaps G from the outer surfaces 75a2, 75b2, 75c2, and 75d2 of the lid portion 75 are kept equal and constant.
[0065] The adhesive member 96 may be poured directly into the gap G. Alternatively, the adhesive member 96 may be poured from the reservoir 75c towards the gap G. In this case, the reservoir 75c functions as a guide for the pouring of the adhesive member 96. That is, the adhesive member 96 poured into the reservoir 75c flows along the reservoir surface 75c1 of the reservoir 75c into the gap G. In particular, because the reservoir surface 75c1 is inclined, the adhesive member 96 can be reliably poured into the gap G. The adhesive member 96 poured into the gap G in this way fills the entire gap G. As previously described, the gap G on each side is approximately equal and maintained at a constant size. Since there are no differences in the gap G, the adhesive member 96 poured from the reservoir 75c flows stably into the entire gap G.
[0066] The adhesive member 96 used in this case is, for example, a thermosetting resin adhesive or an organic adhesive. A thermosetting resin adhesive is, for example, mainly composed of epoxy resin or phenolic resin. An organic adhesive is, for example, an elastomer adhesive mainly composed of silicone rubber or chloroprene rubber. Preferably, it is mainly composed of epoxy resin or silicone rubber. The adhesive member 96 may have the same components as the adhesive member 60a. However, it is preferable that the adhesive member 96 has higher fluidity than the adhesive member 60a. When such an adhesive member 96 is poured from the reservoir 75c, it is easier for it to spread throughout the entire gap G from the reservoir 75c.
[0067] Furthermore, the adhesive member 96 that fills the gap G is stored in the storage section 75c. This prevents the adhesive member 96 from overflowing from the gap G, thus preventing waste of the adhesive member 96. By preventing the adhesive member 96 from overflowing, adhesion of the adhesive member 96 to the lid 75 and the case 50 is suppressed, thereby preventing contamination of the semiconductor device 10.
[0068] In this way, the gap G is filled, and the adhesive member 96 stored in the storage section 75c solidifies, fixing the lid 75 to the stepped sections 72a, 72b, 72c, and 72d of the frame 70. Since the adhesive member 96 extends not only to the gap G but also to the storage section 75c, the bonding area of the adhesive member 96 to the lid 75 increases compared to the case where there is no storage section 75c. Therefore, the bonding force of the lid 75 to the frame 70 (case 50) via the adhesive member 96 is improved.
[0069] [Modification 2-1] A modified example 2-1 of the second embodiment will be described with reference to Figure 7. Figure 7 is a cross-sectional view of the mounting location between the lid and case of the semiconductor device in modified example 2-1 of the second embodiment. Note that in Figure 7, only the storage surface 75c1 of the storage section 75c is different from that in Figure 6; the other configurations are the same.
[0070] In the modified example 2-1, as shown in Figure 7, the storage section 75c has a storage surface 75c1 that connects the front surface 75a and the outer surface 75c2 in a curved manner. That is, in the storage section 75c of the modified example 2-1, the outside of the lid 75 face 7 The corners of the front surface 75a of 5c2 are rounded off. Even with this type of storage section 75c, the same effect as the storage section 75c shown in Figure 6 can be obtained.
[0071] Furthermore, in Figures 1, 6, and 7, multiple protrusions may be appropriately formed on the storage surfaces 3c1, 75c1 and inner surfaces 3c3, 3c4, 75c3, and 75c4 of the storage sections 3c and 75c. Such protrusions increase the bonding area of the adhesive member 96 stored in the storage section 75c, thereby improving the bonding strength.
[0072] [Modification 2-2] A modified example 2-2 of the second embodiment will be described with reference to Figure 8. Figure 8 is a plan view of the mounting location between the lid and case of the semiconductor device in modified example 2-2 of the second embodiment. Note that in Figure 8, only the inner surfaces 75c3 and 75c4 of the storage section 75c are different from those in Figure 5; the other configurations are the same.
[0073] In modified example 2-2, the inner surfaces 75c3 and 75c4 of the reservoir 75c are inclined in plan view. That is, the gap between the inner surfaces 75c3 and 75c4 widens as it moves toward the outer surface 75c2. In other words, the gap between the inner surfaces 75c3 and 75c4 narrows as it moves toward the +X direction from the outer surface 75c2. When adhesive material 96 is poured into such a reservoir 75c, the inner surfaces 75c3 and 75c4 gap Since it widens towards the gap G, the adhesive member 96 can easily flow into the gap G. In addition, grooves may be formed along the inner surfaces 75c3 and 75c4 on the reservoir surface 75c1 to promote the flow of the adhesive member 96 into the gap G. Furthermore, the inner surfaces 75c3 and 75c4 may be provided to widen as they advance in the +Z direction. This makes it easier for the adhesive member 96 to flow into the gap G.
[0074] [Third Embodiment] In the third embodiment, a semiconductor device different from that of the second embodiment will be described using Figures 9 to 11. Figure 9 is a plan view of the semiconductor device of the third embodiment, and Figure 10 is an internal plan view of the semiconductor device of the third embodiment. Figure 11 is a cross-sectional view of the semiconductor device of the third embodiment. Note that Figure 11 is a cross-sectional view taken along the dashed line XX in Figure 9. Note that components similar to those in the second embodiment are denoted by the same reference numerals, and their descriptions may be omitted or simplified.
[0075] The semiconductor device 10a of the third embodiment includes an insulating circuit board 20a, a case 50a housing the insulating circuit board 20a, and a lid 75. The inside of the case 50a is sealed by a sealing member 95. Furthermore, a metal base substrate 23 is exposed downwards (-Z direction) from the back surface of the case 50a of the semiconductor device 10a.
[0076] Case 50a is rectangular in plan view. Case 50a includes a frame portion 70a and fastening holes 73a, 73b, 73c, and 73d. The frame portion 70a is rectangular (frame-shaped) in plan view. The frame portion 70a has a storage area 72 in the center, and the four sides of the storage area 72 are formed in the order of side walls 71a, 71b, 71c, and 71d. The side walls 71a and 71c are located on the longer sides, and the side walls 71b and 71d are located on the shorter sides. Furthermore, the frame portion 70a only needs to have straight side walls 71a, 71b, 71c, and 71d on all four sides of the rectangle, and may have curved (curved) sections at the corners.
[0077] The side wall portions 71a, 71b, 71c, and 71d also include stepped portions 72a, 72b, 72c, and 72d, similar to the second embodiment. Protrusions 72a3, 72b3, 72c3, and 72d3 are formed within the stepped portions 72a, 72b, 72c, and 72d.
[0078] Furthermore, the frame portion 70a has a plurality of terminals extending vertically upward (+Z direction) from its front surface. The plurality of terminals include external connection terminals for the main electrode, control, and output of the insulated circuit board (inverter), which will be described later. The external connection terminals for the main electrode are the second P terminal 184a, the second N terminal 185a, the first P terminal 184b, and the first N terminal 185b. The second P terminal 184a and the second N terminal 185a are formed on the side wall portion 71d, extending from the side wall portion 71c to the side wall portion 71a. The first P terminal 184b and the first N terminal 185b are formed on the side wall portion 71b, extending from the side wall portion 71c to the side wall portion 71a.
[0079] The external connection terminals for control are Gx terminal 191, Gu terminal 192, Gy terminal 193, Gv terminal 194, Gz terminal 195, and Gw terminal 196, and are formed on the side wall portion 71a from the side wall portion 71b to the side wall portion 71d. One end of each terminal, Gx terminal 191, Gu terminal 192, Gy terminal 193, Gv terminal 194, Gz terminal 195, and Gw terminal 196, extends upward from the upper surface of the side wall portion 71a. The other ends of terminals Gx 191, Gu 192, Gy 193, Gv 194, Gz 195, and Gw 196 are terminal stepped portions 71 e It is exposed.
[0080] External output terminals are U terminal 181, V terminal 182, and W terminal 183, which are formed on the side wall portion 71c from side wall portion 71b to side wall portion 71d. One end of terminal U 181, terminal V 182, and terminal W 183 extends upward from the upper surface of the side wall portion 71c. The other ends of terminals U 181, V 182, and W 183 have terminal step portions 71. f It is exposed.
[0081] These terminals are made of copper, aluminum, iron, or an alloy containing at least one of these materials, which have excellent conductivity. Furthermore, to improve corrosion resistance, the surfaces of the terminals may be plated with, for example, nickel, gold, tin, or an alloy containing at least one of these materials.
[0082] Such a semiconductor device 10a includes an inverter circuit. The inverter circuit is a circuit that converts direct current to alternating current. Direct current input from the high-potential second P terminal 184a and first P terminal 184b and the low-potential second N terminal 185a and first N terminal 185b is converted by multiple semiconductor chips 31a and 32a and output as three-phase alternating current from the U terminal 181, V terminal 182, and W terminal 183.
[0083] The lid portion 75 is provided to close the opening of the storage area 72 for housing components (semiconductor chips, etc.) of the semiconductor device 10a (see Figure 9). Fastening holes 73a, 73b, 73c, and 73d are provided at the four corners of the frame portion 70a in a plan view. Screws are installed in the fastening holes 73a, 73b, 73c, and 73d. When the semiconductor device 10a is installed in a predetermined location, screws are installed in the fastening holes 73a, 73b, 73c, and 73d to fasten it to that predetermined location. These screws also pass through the fastening holes 73a, 73b, 73c, and 73d and are installed, for example, in the through-holes of the cooling unit (described later), so that the cooling unit is also fastened in the same way as the case 50a.
[0084] Such a case 50a is also formed by integral molding, including multiple terminals, using the same method and resin as in the second embodiment. The lid portion 75 is also formed separately from the same material. The metal base substrate 23 is the same as in the second embodiment. Such a metal base substrate 23 is fixed to the back surface opening 63 on the back surface of the frame portion 70 by an adhesive member.
[0085] Furthermore, the semiconductor device 10a is located on a metal base substrate 23, and three insulating circuit boards 20a are arranged along the side walls 71a and 71c in the housing area 72 of the case 50a. The insulating circuit board 20a includes an insulating plate 21, a circuit pattern 22 formed on the insulating plate 21, and a metal plate 23a formed on the back surface of the insulating plate 21. The insulating plate 21 and the circuit pattern 22 are made of the same material as in the second embodiment. However, the circuit pattern 22 is formed in a different shape and number than in the second embodiment.
[0086] The metal plate 23a is formed on the entire surface of the back surface of the insulating plate 21, excluding the outer periphery. The metal plate 23a is mainly composed of a metal with excellent thermal conductivity. Such a metal is, for example, copper, aluminum, or an alloy containing at least one of these. The thickness of the metal plate 23a is 0.1 mm or more and 5.0 mm or less. Plating treatment may be performed on the surface of the metal plate 23a to improve corrosion resistance. Examples of plating materials used in this case include nickel, nickel-phosphorus alloy, and nickel-boron alloy.
[0087] An insulating circuit board 20a having such a configuration may be, for example, a DCB board or an AMB board. The insulating circuit board 20a can conduct the heat generated by the semiconductor chips 31a and 32a to the outside through the circuit pattern 22, the insulating plate 21, and the metal plate 23a.
[0088] The semiconductor chips 31a and 32a are mainly composed of silicon, silicon carbide, or gallium nitride. Such semiconductor chips 31a and 32a contain RC (Reverse-Conducting) IGBTs. Such semiconductor chips 31a and 32a have an input electrode (collector electrode) as the main electrode on the back surface, and a gate electrode as the control electrode and an output electrode (emitter electrode) as the main electrode on the front surface.
[0089] The insulated circuit board 20a and semiconductor chips 31a and 32a are housed together, and each circuit pattern 22, semiconductor chips 31a and 32a, and multiple terminals are electrically and mechanically connected as appropriate by wires (not shown). As a result, the inverter circuit is included within the housing area 72.
[0090] The lid portion 75 that covers the insulating circuit board 20a and semiconductor chips 31a and 32a housed in the frame portion 70a of the case 50a also has a storage portion 75c formed therein, similar to the second embodiment. In the third embodiment, five storage portions 75c are formed on each of the opposing long sides of the front surface 75a of the lid portion 75. As previously described, the storage portions 75c are formed to account for the warping of the case 50a when fastening it using the fastening holes 73a, 73b, 73c, and 73d.
[0091] Furthermore, one of the storage portions 75c is formed in the lid portion 75 so as to correspond to the central location of the side wall portions 71a, 71c of the frame portion 70a. When the semiconductor device 10a is driven and repeatedly heated and cooled, warping occurs due to the difference in the coefficient of thermal expansion of each component. Since the semiconductor device 10a has a rectangular shape in plan view, warping occurs in a concave and convex shape with the center as the apex in plan view. At this time, stress occurs in the centers of the side wall portions 71a, 71c and the centers of the side wall portions 71b, 71d, respectively. If the storage portion 75c is not formed in the lid portion 75, the lid portion 75 may detach from the frame portion 70a due to stress, even if it is bonded to the frame portion 70a by the adhesive member 96. On the other hand, if the storage portion 75c is formed in the location where stress occurs, the bonding strength of the adhesive member 96 is improved by the storage portion 75c, so that the detachment of the lid portion 75 from the frame portion 70a is suppressed.
[0092] The third embodiment shows a case in which the storage portion 75c is not formed on the side wall portions 71b and 71d of the lid portion 75. When the storage portion 75c is formed on the side wall portions 71b and 71d of the lid portion 75, it is preferable to form it at a location corresponding to the center of the side wall portions 71b and 71d.
[0093] Furthermore, the storage section 75c of the third embodiment may have a storage surface parallel to the front surface 75a, similar to the storage section 3c of the first embodiment. Also, as shown in Figures 7 and 8, the storage section 75c of the third embodiment may have a curved storage surface and be configured such that the opposing inner surfaces widen. [Explanation of Symbols]
[0094] 1,10,10a Semiconductor device 2.50.50a case 2a,70,70a frame 2b Stepped section 2b1 Inner surface of step 2b2 Step support surface 2c,72 Storage area 2d,60 bottom 2e,74a,74c Inner periphery of opening 3 Lid 3a Front side 3b Bottom 3c Reservoir 3c1 Storage surface 3c2 outer surface 3c3,3c4 inner surface 4,60a,96 Adhesive member 20 Main circuit board 20a Insulated Circuit Board 21 Insulating board 22 Circuit Patterns 23 Metal-based substrate 23a metal plate 30 Semiconductor Units 31,31a First semiconductor chip 32,32a Second semiconductor chip 33,43 Bonding wires 40 Printed circuit boards 41 Control ICs 61 Main circuit area 62 Control Circuit Domain 63 Rear opening 71a,71b,71c,71d Side wall part 71e, 71f Terminal step section 72a, 72b, 72c, 72d Stepped section 72 c 1. Inner surface of the step 72 c 2-step support surface 72a3,72b3,72c3,72d3 Protrusion 73,73a,73b,73c,73d Fastening hole 75 Lid 75a Front side 75b Reverse side 75b1 Fixing hole 75c reservoir 75c1 Storage surface 75a2,75b2,75c2,75d2 Outer surface 75c3,75c4 Inner surface 76 Positioning member 80, 80a, 80b, 80c, 80d, 80e Main current connection terminals 81, 81a, 81b, 81c, 81d, 81e External connection section 82, 82a, 82b, 82c, 82d, 82e Internal connection section 90 Control terminals 91 External terminal section 92 Internal terminal section 95 Sealing member 181 U terminal 182V terminal 183 W terminal 184a 2nd P terminal 185a 2nd N terminal 184b 1st P terminal 185b First N terminal 191 Gx terminal 192 Gu terminal 193 Gy terminal 194 Gv terminal 195 Gz terminal 196 Gw terminal
Claims
1. Semiconductor elements and A case comprising a frame portion that forms a frame shape in plan view and includes an inner peripheral opening surrounding the storage area in which the semiconductor element is housed, A lid portion that is flat and covers the upper part of the storage area, Equipped with, The inner circumference of the opening is lower than the front surface of the frame and has a stepped portion formed thereon, which has a stepped support surface that is substantially parallel to the front surface of the frame. The aforementioned lid portion is The outer surface surrounding the periphery is joined to the stepped portion by an adhesive member. The bottom surface of the lid is substantially parallel to the stepped support surface, A storage portion is formed on the front surface of the lid, including a storage surface that is lower than the front surface of the lid, extending inward from the outer surface. The storage portion is formed in a part of the outer circumference of the lid portion, The storage portion is formed in plan view at the center of at least one pair of opposing sides on the outer periphery of the front surface of the lid portion. Semiconductor equipment.
2. The storage surface, in cross-sectional view, slopes upward from the outer surface toward the front surface of the lid. The semiconductor device according to claim 1.
3. The storage surface, in cross-sectional view, has a curved surface extending from the outer surface towards the inner surface. The semiconductor device according to claim 1 or 2.
4. The aforementioned storage surface is substantially parallel to the front surface of the lid in cross-sectional view. The semiconductor device according to claim 1.
5. The stepped portion is formed continuously around the entire circumference of the inner circumference of the opening. A semiconductor device according to any one of claims 1 to 4.
6. The frame portion includes a projection formed on the step support surface of the step portion. The back surface of the outer periphery of the lid is fitted onto the projection and supported by the stepped support surface. The semiconductor device according to claim 5.
7. The stepped portion includes a stepped inner circumferential surface that is connected to the stepped support surface along the inner circumferential portion of the opening and is formed at a substantially right angle to the stepped support surface. The lid portion is arranged such that the outer surface and the inner surface of the step are substantially parallel, and a gap is provided between the outer surface and the inner surface of the step. A semiconductor device according to any one of claims 1 to 6.
8. The storage surface of the storage portion of the lid that is joined to the stepped portion is connected to the outer surface, and the outer surface is substantially parallel to the inner circumferential surface of the step. The semiconductor device according to claim 7.
9. The adhesive member is filled into the gap. The semiconductor device according to claim 7.
10. The front surface of the adhesive member is lower than the front surface of the frame portion. A semiconductor device according to any one of claims 1 to 9.
11. The case further has fastening holes on a pair of opposing sides of the frame portion in a plan view, each opening in the same direction as the storage area. The storage portion is formed in the portion of the front surface of the lid that curves when the case is fastened by the fastening hole. The semiconductor device according to claim 1.
12. The aforementioned storage surface has a rectangular shape when viewed from above. A semiconductor device according to any one of claims 1 to 11.
13. The storage surface further has a trapezoidal shape in plan view, where the length of the outer surface is longer than the length of the inner surface. The semiconductor device according to claim 1.
14. A positioning member is further formed that extends vertically upward from a predetermined location on the outer periphery of the front surface of the lid, The storage portion is formed on the front surface of the lid portion, except for the vicinity of the predetermined location. A semiconductor device according to any one of claims 1 to 10.
15. The case further includes an external connection terminal integrally molded with the frame, one of which extends vertically upward from the front surface of the frame, and the other extending into the storage area. A semiconductor device according to any one of claims 1 to 14.
16. A semiconductor element, A case comprising a frame portion that forms a frame shape in plan view and includes an inner peripheral opening surrounding the storage area in which the semiconductor element is housed, A lid portion that is flat and covers the upper part of the storage area, Equipped with, The inner circumference of the opening is lower than the front surface of the frame and has a stepped portion formed thereon, which has a stepped support surface that is substantially parallel to the front surface of the frame. The aforementioned lid portion is The outer surface surrounding the periphery is joined to the stepped portion by an adhesive member. The bottom surface of the lid is substantially parallel to the stepped support surface, A storage portion is formed on the front surface of the lid, including a storage surface that is lower than the front surface of the lid, extending inward from the outer surface. The stepped portion is formed continuously around the entire circumference of the inner circumference of the opening. The storage section is located inside the stepped section. Semiconductor equipment.
17. A semiconductor element, A case comprising a frame portion that forms a frame shape in plan view and includes an inner peripheral opening surrounding the storage area in which the semiconductor element is housed, A lid portion that is flat and covers the upper part of the storage area, Equipped with, The inner circumference of the opening is lower than the front surface of the frame and has a stepped portion formed thereon, which has a stepped support surface that is substantially parallel to the front surface of the frame. The aforementioned lid portion is The outer surface surrounding the periphery is joined to the stepped portion by an adhesive member. The bottom surface of the lid is substantially parallel to the stepped support surface, A storage portion is formed on the front surface of the lid, including a storage surface that is lower than the front surface of the lid, extending inward from the outer surface. The storage section is located inside the stepped section. The case further includes an external connection terminal integrally molded with the frame, one of which extends vertically upward from the front surface of the frame, and the other extending into the storage area. Semiconductor equipment.