Semiconductor device and electric power conversion device

Abstract

To provide technology that makes it possible to improve the bond strength of internal wiring and terminals while securing heat dissipation in a semiconductor device.SOLUTION: A semiconductor device 202 comprises: a substrate 2 having an insulating layer 4 and a conductive pattern 5; a semiconductor element 6 mounted on the conductive pattern 5; a frame-like resin case 9 secured to a circumferential part of the substrate 2 by an adhesive 10; a terminal 11 attached to the resin case 9; and an internal wiring 7 for connecting the semiconductor element 6 and the terminal 11. The resin case 9 includes a circumferential wall part 9a, a terminal installation part 20 protruding to the inner circumferential side from the circumferential wall part 9a, at which the terminal 11 is disposed, and a substrate installation part 26 protruding downward from the terminal installation part 20 and facing the top of the substrate 2. The substrate installation part 26 and the insulating layer 4 exposed in the circumferential part of the substrate 2 are secured by the adhesive 10, and the substrate installation part 26 is located directly beneath a connecting part 21 with the internal wiring 7 of the terminal 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a semiconductor device and a power conversion device. [Background technology]

[0002] Semiconductor devices are mounted on inverters installed in electric trains, automobiles, and factory automation equipment. Many semiconductor devices have a structure in which a case with terminals is fixed to the periphery of a substrate with adhesive, and the inside of the case is sealed. Furthermore, a structure is adopted in which the case is attached to a heat dissipation member with screws or the like, so that heat generated from the semiconductor element mounted on the semiconductor device is dissipated via the heat dissipation member. In such semiconductor devices, if the back surface of the substrate is recessed from the bottom end of the substrate, it becomes difficult to attach the substrate to an external heat dissipation member, and the heat dissipation performance decreases.

[0003] To solve this problem, for example, in the semiconductor device described in Patent Document 1, a spacer having elasticity such as rubber is disposed between the stepped seat surface of the case and the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2000-133769 A Summary of the Invention [Problem to be solved by the invention]

[0005] In wire bonding, ultrasonic vibration is applied to the wire (corresponding to the internal wiring) to apply friction to the terminal and bond it, but in this process, the back surface of the substrate is fixed by suction or the like to prevent the terminal from moving. In the case where the spacer has rubber-like elasticity and has multiple bonding surfaces, such as the bonding surface between the case and the spacer and the bonding surface between the spacer and the substrate, as in the semiconductor device described in Patent Document 1, the ultrasonic vibration during wire bonding is dispersed, making it impossible to efficiently bond the wire to the terminal. As a result, the bonding strength between the wire and the terminal may decrease.

[0006] In view of the above, an object of the present disclosure is to provide a technique capable of improving the bonding strength between the internal wiring and the terminals in a semiconductor device while ensuring heat dissipation. [Means for solving the problem]

[0007] The semiconductor device according to the present disclosure comprises a substrate having an insulating layer and a conductive pattern formed on the insulating layer, a semiconductor element mounted on the conductive pattern, a frame-shaped case fixed to a peripheral portion of the substrate with an adhesive, a terminal attached to the case, and internal wiring connecting the semiconductor element and the terminal, the case having a peripheral wall portion, a terminal installation portion protruding inwardly from the peripheral wall portion and having the terminal installed thereon, and a substrate installation portion protruding downwardly from the terminal installation portion and facing an upper surface of the substrate, the conductive pattern is not formed on the peripheral portion of the substrate and the insulating layer is exposed, the substrate installation portion and the insulating layer exposed at the peripheral portion of the substrate are fixed by the adhesive, and the substrate installation portion is located directly below a connection portion of the terminal with the internal wiring. Effect of the Invention

[0008] According to the present disclosure, since the case has a board installation part that protrudes downward from the terminal installation part, the back surface of the board can be protruded beyond the bottom end of the case without adding a spacer. As a result, it is possible to closely contact the board with an external heat dissipation member, and the heat dissipation of the semiconductor device can be ensured.

[0009] Furthermore, since the board mounting portion is located directly below the connection portion, the thickness of the adhesive located below the board mounting portion is thinner than when the board mounting portion is not provided, so that ultrasonic vibrations are less likely to disperse in the adhesive during wire bonding, thereby improving the bonding strength between the internal wiring and the terminals. [Brief description of the drawings]

[0010] [Figure 1] 1 is a top view of a semiconductor device according to a first embodiment. [Diagram 2] 2 is a cross-sectional view of the periphery of a terminal installation portion of the semiconductor device according to the first embodiment. [Diagram 3] 4 is a flowchart showing a method for manufacturing the semiconductor device according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing an adhesive application step in the first embodiment. [Diagram 5] 4 is a cross-sectional view showing a bonding step of a resin case in the first embodiment. FIG. [Figure 6] 3A to 3C are cross-sectional views showing a wire bonding step and a sealing step in the first embodiment. [Figure 7] 5A to 5C are cross-sectional views showing a process of attaching the semiconductor device according to the first embodiment to an external heat dissipation component. [Figure 8] 11 is a cross-sectional view of the periphery of a terminal installation portion included in a semiconductor device according to a modified example of the first embodiment. FIG. [Figure 9] 11 is a cross-sectional view of the periphery of a terminal installation portion of a semiconductor device according to a second embodiment. FIG. [Figure 10] 11 is a cross-sectional view of the periphery of a terminal installation portion of a semiconductor device according to a third embodiment. [Figure 11] 13 is a cross-sectional view of the periphery of a terminal installation portion in a screw-fastened state in the third embodiment. FIG. [Figure 12] FIG. 11 is a block diagram showing a configuration of a power conversion system to which a power conversion device according to a fourth embodiment is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Embodiment 1> The first embodiment will be described below with reference to the drawings. Fig. 1 is a top view of a semiconductor device 202 according to the first embodiment. Fig. 2 is a cross-sectional view of the periphery of a terminal installation portion 20 provided in the semiconductor device 202 according to the first embodiment. Note that in Fig. 1, the sealing material 12 is omitted to make the internal structure easier to see.

[0012] First, a description will be given of the configuration of the semiconductor device 202. As shown in Fig. 1 and Fig. 2, the semiconductor device 202 includes a substrate 2, a plurality of semiconductor elements 6, a resin case 9 (corresponding to a case), a plurality of terminals 11, and a sealing material 12.

[0013] The substrate 2 includes an insulating layer 4, a metal plate 3 provided on the lower surface of the insulating layer 4, and a conductive pattern 5 formed on the upper surface of the insulating layer 4.

[0014] The insulating layer 4 is preferably made of a resin, but may be made of an inorganic material such as ceramic. The conductive pattern 5 is made of, for example, a metal. The thickness of the metal plate 3 is preferably 0.5 mm or more.

[0015] The semiconductor elements 6 are mounted on the upper surface of the conductive pattern 5 via a bonding material (not shown). The bonding material has electrical conductivity. The bonding material is, for example, solder, Ag paste, or sintering paste.

[0016] The semiconductor elements 6 are configured with power semiconductor elements, a control IC (Integrated Circuit) for controlling the power semiconductor elements, etc. The semiconductor elements 6 are, for example, IGBTs (Insulated Gate Bipolar Transistors), MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), Schottky barrier diodes, etc. Alternatively, the semiconductor elements 6 may be RC-IGBTs (Reverse-Conducting IGBTs) in which an IGBT and a freewheeling diode are formed in one semiconductor substrate.

[0017] The semiconductor elements 6 are made of silicon or a wide band gap semiconductor. The wide band gap semiconductor is a semiconductor material including silicon carbide, gallium nitride, gallium oxide, or diamond. The semiconductor elements 6 made of a wide band gap semiconductor can reduce the power loss of the semiconductor device 202.

[0018] The resin case 9 includes a peripheral wall portion 9a formed in a frame shape (specifically, a rectangular frame shape) so as to surround the periphery of the multiple semiconductor elements 6, a terminal installation portion 20 protruding from the peripheral wall portion 9a toward the inner periphery, and a board installation portion 26 protruding downward from the terminal installation portion 20. The terminal installation portion 20 is formed, for example, continuously around the entire circumference of the peripheral wall portion 9a. The board installation portion 26 is formed, for example, discontinuously around the entire circumference of the peripheral wall portion 9a. The outline shape of the board installation portion 26 is smaller than the outline shape of the terminal installation portion 20. That is, the width of the board installation portion 26 is narrower than the width of the terminal installation portion 20. The width of the board installation portion 26 is approximately the same dimension from the base end (the portion connected to the terminal installation portion 20) to the tip.

[0019] 2, no conductive pattern 5 is formed on the peripheral portion of the substrate 1, and the insulating layer 4 is exposed. A resin case 9 is adhered with an adhesive 10 to the portion of the peripheral portion of the substrate 1 where the insulating layer 4 is exposed.

[0020] The resin case 9 is made of a resin material such as PPS (Polyphenylene Sulfide) or PBT (Polybutylene Terephthalate). A plurality of terminals 11 are attached to the resin case 9 to electrically connect, for example, external wiring to the substrate 1. The external wiring is not shown in the figure.

[0021] Furthermore, screw holes 13 are formed in the four corners of the lower end of the resin case 9. The screw holes 13 are located closer to the outer periphery than the substrate 2, and are used when attaching the semiconductor device 202 to an external heat dissipation member 30 (see FIG. 7).

[0022] 2, terminal 11 is formed in an L-shape in a cross-sectional view, and one end side is installed on the upper surface of terminal installation portion 20. Meanwhile, the other end side of terminal 11 is installed within peripheral wall portion 9a, and the other end side of terminal 11 protrudes from the upper end of peripheral wall portion 9a.

[0023] In addition, in the resin case 9, a slit portion 27 recessed upward is formed in a portion between the peripheral wall portion 9a and the board installation portion .

[0024] The substrate installation portion 26 is in surface contact with the insulating layer 4 of the substrate 2 via the adhesive 10. The slit portion 27 contains a portion of the adhesive 10 that bonds the resin case 9 and the substrate 1, but an area in which the adhesive 10 is not contained is provided above the slit portion 27.

[0025] The adhesive 10 serves to bond the peripheral wall portion 9a, the slit portion 27, and the substrate mounting portion 26 of the resin case 9 to the substrate 2.

[0026] Here, an adhesive having insulating properties and thermoplastic or thermosetting properties that hardens when heated is used as the adhesive 10. Also, a material containing silicone, a resin material containing epoxy or acrylic, or a ceramic containing SiO2 may be used as the material of the adhesive 10. Also, it is desirable that the adhesive 10 has a lower elastic modulus than the resin case 9 and the insulating layer 4.

[0027] As shown in Fig. 1, the internal wiring 7 electrically connects the terminal 11, the semiconductor element 6, and the conductive pattern 5 to one another. As shown in Fig. 2, for example, one end of the internal wiring 7 is joined to a connection portion 21 located on a flat portion on one end side of the terminal 11, and as shown in Fig. 1, the other end of the internal wiring 7 is joined to an electrode (not shown) of the semiconductor element 6 or the conductive pattern 5. In other words, the internal wiring 7 connected to the semiconductor element 6 or the internal wiring 7 connected to the conductive pattern 5 is joined to the terminal 11.

[0028] Furthermore, the board installation portion 26 is located directly below the connection portion 21 of the terminal 11 with the internal wiring 7. The thickness of the adhesive 10 located below the board installation portion 26 is thinner than when the board installation portion 26 is not provided, so that ultrasonic vibration is less likely to disperse in the adhesive 10 during wire bonding, and the internal wiring 7 and the terminal 11 are fixed more firmly and stably.

[0029] Here, the internal wiring 7 is a metal wire. The metal wire is made of, for example, aluminum. The internal wiring 7 is not limited to a metal wire, and may be a metal frame or a metal ribbon formed by processing a thin metal plate.

[0030] The sealing material 12 seals the semiconductor element 6, one end side of the terminals 11, the adhesive 10, the internal wiring 7, and the like, which are housed on the inner periphery side of the peripheral wall portion 9a of the resin case 9. Here, the sealing material 12 is not filled into the slit portion 27 of the resin case 9. The sealing material 12 is, for example, a resin containing silicone gel. The sealing material 12 may also be a thermosetting resin such as an epoxy resin.

[0031] In FIG. 2, the back surface of substrate 2 protrudes downward from the lower end of resin case 9, but the back surface of substrate 2 and the lower part of resin case 9 may be on the same plane.

[0032] Next, a method for manufacturing the semiconductor device 202 according to the first embodiment will be described with reference to Fig. 3 to Fig. 6. Fig. 3 is a flowchart showing a method for manufacturing the semiconductor device 202 according to the first embodiment. Fig. 4 is a cross-sectional view showing a step of applying the adhesive 10 in the first embodiment. Fig. 5 is a cross-sectional view showing a step of adhering the resin case 9 in the first embodiment. Fig. 6 is a cross-sectional view showing a wire bonding step and a sealing step in the first embodiment. Fig. 7 is a cross-sectional view showing a step of attaching the semiconductor device 202 according to the first embodiment to an external heat dissipation member 30.

[0033] First, the substrate 2 on which a plurality of semiconductor elements 6 are mounted is prepared by die bonding or the like. Next, as shown in Figs. 3 and 4, an uncured adhesive 10 is applied to a predetermined region on the insulating layer 4 of the substrate 2 (step S1). The adhesive 10 is applied to all of the insulating layer 4 with which the resin case 9 comes into contact. Here, the adhesive 10 is applied to the portion of the peripheral portion of the substrate 2 where the insulating layer 4 is exposed. Preferably, the adhesive 10 is applied so as to spread to the side surface of the insulating layer 4 and the side surface of the metal plate 3.

[0034] Next, as shown in FIG. 3 and FIG. 5, after the adhesive 10 is applied, the resin case 9 is placed at a predetermined position on the substrate 2 (step S2). At this time, the adhesive 10 spreads between the resin case 9 and the insulating layer 4 at the peripheral portion of the substrate 2. Specifically, the adhesive 10 spreads over the inner peripheral surface of the lower portion of the peripheral wall portion 9a, the substrate installation portion 26, the lower portion of the slit portion 27, and the insulating layer 4. An area in which the adhesive 10 is not contained exists in the upper portion of the slit portion 27. In order to make the thickness of the adhesive 10 uniform, a load is applied from the upper end to the lower end of the resin case 9 to bring the substrate installation portion 26 as close as possible to the substrate 2. In this state, the substrate 2 and the resin case 9 are put into a curing furnace and heat treatment is performed. By the thermal curing of the adhesive 10, the resin case 9 is fixed to the substrate 2 so as to surround the peripheral portion of the substrate 2.

[0035] 3 and 6, a wire bonding process is performed to electrically connect the terminal 11, the semiconductor element 6, and the conductive pattern 5 to one another (step S3). One end of the internal wiring 7 is pressed against a flat portion on one end side of the terminal 11 by an ultrasonic tool. In this state, vibration is applied from the ultrasonic tool, and one end of the internal wiring 7 is joined to the connection portion 21 of the terminal 11.

[0036] Similarly, the other end of the internal wiring 7 is joined to an electrode (not shown) of the semiconductor element 6 or to the conductive pattern 5. This wire bonding process is performed in a state where the resin case 9 is fixed to the substrate 2 by the adhesive 10. Note that in FIG. 6, only the wire bonding to the terminal 11 is shown.

[0037] 3 and 6, the inside of the resin case 9 is sealed with a sealant 12 such as silicone gel. First, the sealant 12 is filled onto the substrate 2 inside the resin case 9. If the sealant 12 has a curing property, the sealant 12 is then cured to seal the semiconductor element 6, the adhesive 10, the internal wiring 7, and the like, and the semiconductor device 202 is completed.

[0038] 7, the semiconductor device 202 is placed on the upper surface of the heat dissipation member 30 with heat dissipation grease (not shown) therebetween. The semiconductor device 202 is fixed to the heat dissipation member 30 by passing the screws 31 through the screw holes 13 of the resin case 9 and the screw holes 30a of the heat dissipation member 30 and tightening them.

[0039] Next, the effect of the first embodiment will be described. The semiconductor device 202 according to the first embodiment includes a substrate 2 having an insulating layer 4 and a conductive pattern 5 formed on the insulating layer 4, a semiconductor element 6 mounted on the conductive pattern 5, a frame-shaped resin case 9 fixed to the peripheral portion of the substrate 2 by an adhesive 10, a terminal 11 attached to the resin case 9, and an internal wiring 7 connecting the semiconductor element 6 and the terminal 11. The resin case 9 has a peripheral wall portion 9a, a terminal installation portion 20 protruding from the peripheral wall portion 9a toward the inner peripheral side and having the terminal 11 installed thereon, and a substrate installation portion 26 protruding downward from the terminal installation portion 20 and facing the upper surface of the substrate 2, the conductive pattern 5 is not formed on the peripheral portion of the substrate 2, the insulating layer 4 is exposed, the substrate installation portion 26 and the insulating layer 4 exposed at the peripheral portion of the substrate 2 are fixed by an adhesive 10, and the substrate installation portion 26 is located directly below a connection portion 21 between the terminal 11 and the internal wiring 7.

[0040] Therefore, since the resin case 9 has the substrate mounting portion 26 protruding downward from the terminal mounting portion 20, the back surface of the substrate 2 can be made to protrude beyond the lower end of the resin case 9 without adding a spacer. As a result, the substrate 2 can be brought into close contact with the external heat dissipation member 30, and the heat dissipation properties of the semiconductor device 202 can be ensured.

[0041] Furthermore, since the board mounting portion 26 is located directly below the connection portion 21 and the thickness of the adhesive 10 located below the board mounting portion 26 is thinner than when the board mounting portion 26 is not provided, ultrasonic vibrations are less likely to disperse in the adhesive 10 during wire bonding. As a result, the bonding strength between the internal wiring 7 and the terminal 11 can be improved.

[0042] Furthermore, in the step of applying the adhesive 10 (step S1), the amount of adhesive 10 applied varies depending on the viscosity of the adhesive 10 and the amount of adhesive 10 remaining in the syringe. If the amount applied increases, the adhesive 10 may wet and spread toward the substrate 2, resulting in contact with the conductive pattern 5 and a decrease in insulation.

[0043] In contrast, in embodiment 1, a slit portion 27 in which adhesive 10 is contained is formed in the portion between the peripheral wall portion 9a and the substrate mounting portion 26 in the resin case 9, and the slit portion 27 includes an area in which adhesive 10 is not contained.

[0044] Therefore, even if the amount of adhesive 10 applied is increased, the amount of adhesive 10 that flows into slit portion 27 and spreads toward conductive pattern 5 can be reduced, thereby improving product yield.

[0045] Furthermore, as shown in FIG. 6, when the substrate 2 protrudes downward from the lower end of the resin case 9 by a protrusion amount h, when the resin case 9 and the heat dissipation member 30 are screwed together, there is a possibility that the screw holes 13 will float from the heat dissipation member 30 by the protrusion amount h.

[0046] In the first embodiment, when the screw is tightened, the board installation portion 26 has the effect of elastically deforming the adhesive 10 having a low elastic modulus. The adhesive 10 pushed aside by the board installation portion 26 moves left and right, one of which can move to the conductive pattern 5 side, and the other can move to an area in the slit portion 27 where the adhesive 10 is not accommodated. If the slit portion 27 is completely filled with the adhesive 10, the adhesive 10 has nowhere to go inside the slit portion 27, but by providing an area where the adhesive 10 is not accommodated, the elastically deformed adhesive 10 can move into the slit portion 27. In addition, by providing the slit portion 27, the thickness of the resin case 9 in the thickness direction becomes thinner, so that the rigidity of the resin case 9 decreases and the resin case 9 becomes more likely to deform.

[0047] As a result, even if the bottom surface of the substrate 2 protrudes from the lower end of the resin case 9, the screw holes 13 can come into contact with the heat dissipation member 30 by tightening the screws, thereby ensuring stable heat dissipation even during temperature cycles.

[0048] Furthermore, screw holes 13 are formed in the four corners of the resin case 9, and the screw holes 13 are located on the outer periphery side of the substrate 2.

[0049] When the screws are tightened, the resin case 9 itself also deforms, helping the screw holes 13 to come into contact with the heat dissipation member 30. The closer the distance between the substrate 2 and the screw holes 13, the less likely the resin case 9 is to deform; however, as in the first embodiment, the adhesive 10 can elastically deform to absorb the protrusion amount h of the substrate 2. Since the contribution of the resin case 9 to deformation can be reduced, the screw holes 13 can be positioned closer to the substrate 2. This allows the semiconductor device 202 to be made more compact.

[0050] Furthermore, the contour shape of the board installation portion 26 is smaller than the contour shape of the terminal installation portion 20. In other words, the width of the board installation portion 26 is narrower than the width of the terminal installation portion 20. In the bonding process (step S2) of the resin case 9, the surface pressure applied to the adhesive 10 when a load is applied to the resin case 9 increases, and the uncured adhesive 10 is more likely to escape from the lower side of the board installation portion 26, so that the board installation portion 26 can push aside the adhesive 10. Therefore, the thickness of the adhesive 10 located on the lower side of the board installation portion 26 can be minimized, preferably to 100 μm or less, and the bondability of the internal wiring 7 during wire bonding is stabilized.

[0051] If the thickness of the metal plate 3 is set to 0.5 mm or more, the fixing of the substrate 2 during wire bonding is stable, and the bondability of the internal wiring 7 is further stabilized.

[0052] In addition, the back surface of the substrate 2 protrudes downward below the lower end of the resin case 9. Therefore, since a surface pressure can be applied between the substrate 2 and the heat dissipation member 30 when the screws are fastened, the thickness of the heat dissipation grease (not shown) applied between the substrate 2 and the heat dissipation member 30 can be made thinner. By bringing the screw holes 13 into contact with the heat dissipation member 30, the heat dissipation performance of the semiconductor device 202 can be improved, and the life of the semiconductor device 202 can be extended.

[0053] Moreover, the insulating layer 4 and the adhesive 10 are made of a resin-based material. Therefore, the adhesive strength between the insulating layer 4 and the adhesive 10 is strong. Even in an environment where the temperature changes, high adhesive strength can be obtained. This not only stabilizes the bonding quality in the wire bonding process, but also improves reliability against temperature change cycles.

[0054] Moreover, the semiconductor element 6 is made of a wide band gap semiconductor material. The wide band gap semiconductor material is any one of silicon carbide, gallium nitride-based materials, and diamond. Therefore, it is possible to reduce the power loss of the semiconductor device 202. Furthermore, the wide band gap semiconductor is used at high temperatures, but even in this case, stable heat dissipation can be ensured, so that the semiconductor device 202 can have high reliability.

[0055] <Modification of the first embodiment> Next, a description will be given of a modification of the first embodiment. Fig. 8 is a cross-sectional view of the periphery of a terminal installation portion 20 provided in a semiconductor device 202 according to a modification of the first embodiment.

[0056] As shown in Fig. 8, in the modification of the first embodiment, the tip of the substrate mounting portion 26 is formed with a tapered portion 40 having a width smaller than the width of the remaining portion. By providing the tapered portion 40 at the tip of the substrate mounting portion 26, the thickness of the adhesive 10 applied between the substrate mounting portion 26 and the substrate 2 can be made thinner when a load is applied to the resin case 9 in the bonding step (step S2) of the resin case 9 than in the first embodiment, and the tapered portion 40 easily pushes aside the adhesive 10 when the screws are tightened. This stabilizes the bondability of the internal wiring 7 during wire bonding and the heat dissipation during temperature cycles.

[0057] <Embodiment 2> Next, a semiconductor device 202 according to a second embodiment will be described. Fig. 9 is a cross-sectional view of the periphery of a terminal installation portion 20 included in the semiconductor device 202 according to the second embodiment. Note that in the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0058] 9, in the second embodiment, a tapered portion 50 is formed on the tip side of the substrate mounting portion 26. The tapered portion 50 is provided in a portion of the substrate mounting portion 26 facing the peripheral wall portion 9a, and is formed in an inclined shape so as to move away from the peripheral wall portion 9a toward the tip side of the substrate mounting portion 26. Therefore, the tip position of the substrate mounting portion 26 is closer to the conductive pattern 5 than in the first embodiment.

[0059] In the step of applying the adhesive 10 (step S1), the adhesive 10 is applied to the tapered portion 50 of the substrate placement portion .

[0060] In the bonding process (step S2) of the resin case 9, the adhesive 10 spreads toward the peripheral wall portion 9a rather than the tapered portion 50, so that the amount of adhesive 10 that protrudes toward the conductive pattern 5 can be reduced. Since the adhesive 10 is less likely to protrude toward the conductive pattern 5, the distance between the conductive pattern 5 and the adhesive 10 can be reduced, so that the area of ​​the substrate 2 can be reduced. As a result, the semiconductor device 202 can be made smaller.

[0061] Furthermore, by reducing the amount of overflow of the adhesive 10, the area of ​​the sealant 12 in contact with the adhesive 10 can be reduced, making it possible to use an adhesive 10 having a component that induces inhibition of hardening of the silicone gel contained in the sealant 12. As a result, the range of choices for the adhesive 10 can be broadened, increasing the possibility that the adhesive 10 can be used without changing the setup, thereby improving productivity.

[0062] <Embodiment 3> Next, a semiconductor device 202 according to a third embodiment will be described. Fig. 10 is a cross-sectional view of the periphery of a terminal installation portion 20 included in the semiconductor device 202 according to the third embodiment. Note that in the third embodiment, the same components as those described in the first and second embodiments are denoted by the same reference numerals and description thereof will be omitted.

[0063] 10, in the third embodiment, a downwardly recessed cutout portion 60 is formed immediately above the slit portion 27 in the terminal installation portion 20. The cutout portion 60 is formed at the base of the terminal installation portion 20, and is formed continuously around the entire periphery of the peripheral wall portion 9a. The terminal 11 is disposed across the opening of the cutout portion 60. Furthermore, the portion of the cutout portion 60 where the terminal 11 is not disposed is filled with a sealant 12.

[0064] The notch 60 is effective when mounting the semiconductor device 202 on the heat dissipation member 30. Fig. 11 is a cross-sectional view of the periphery of the terminal mounting portion 20 in the screw-fastened state in the third embodiment.

[0065] As shown in FIG. 11, when the screw is fastened, the terminal installation portion 20 is deformed upward with the notch portion 60 as a fulcrum, so that the bottom end of the resin case 9 can be directed toward the heat dissipation member 30. Therefore, even if the back surface of the substrate 2 protrudes significantly from the bottom end of the resin case 9, the terminal installation portion 20 is deformed upward, so that the allowable range of the dimensional tolerance between the resin case 9 and the substrate 2 is improved, and the productivity is improved. In addition, since the thickness of the adhesive 10 can be tolerated, the yield is also improved. Even if the substrate 2 and the screw hole 13 are close to each other, the terminal installation portion 20 is actively deformed, so that the distance between the substrate 2 and the screw hole 13 can be reduced more than in the case of the first embodiment. As a result, the semiconductor device can be miniaturized.

[0066] In addition, in Figures 10 and 11, the shape of the substrate mounting portion 26 is shown to be the same as that of embodiment 1, but this is not limited to this, and the shape of the substrate mounting portion 26 can also be a modified version of embodiment 1 or the same as that of embodiment 2.

[0067] <Fourth embodiment> In this embodiment, the semiconductor device 202 according to the above-mentioned embodiments 1 to 3 is applied to a power conversion device. Although the application of the semiconductor device 202 according to the embodiments 1 to 3 is not limited to a specific power conversion device, a case where the semiconductor device 202 according to the embodiments 1 to 3 is applied to a three-phase inverter will be described below as embodiment 4.

[0068] FIG. 12 is a block diagram showing a configuration of a power conversion system to which a power conversion device 200 according to the fourth embodiment is applied.

[0069] The power conversion system shown in Fig. 12 is composed of a power source 100, a power conversion device 200, and a load 300. The power source 100 is a DC power source and supplies DC power to the power conversion device 200. The power source 100 can be composed of various things, for example, a DC system, a solar cell, or a storage battery, or it may be composed of a rectifier circuit connected to an AC system or an AC / DC converter. The power source 100 may also be composed of a DC / DC converter that converts DC power output from a DC system into a predetermined power.

[0070] The power conversion device 200 is a three-phase inverter connected between the power source 100 and the load 300, converts DC power supplied from the power source 100 into AC power, and supplies the AC power to the load 300. As shown in Fig. 12, the power conversion device 200 includes a main conversion circuit 201 that converts DC power into AC power and outputs it, and a control circuit 203 that outputs a control signal for controlling the main conversion circuit 201 to the main conversion circuit 201.

[0071] The load 300 is a three-phase motor driven by AC power supplied from the power conversion device 200. The load 300 is not limited to a specific use, but is a motor mounted on various electric devices, and is used as, for example, a motor for a hybrid car, an electric car, a railroad car, an elevator, or an air conditioner.

[0072] The power conversion device 200 will be described in detail below. The main conversion circuit 201 includes switching elements (not shown) and free wheel diodes (not shown), and converts DC power supplied from the power source 100 into AC power by switching the switching elements, and supplies the AC power to the load 300. There are various specific circuit configurations of the main conversion circuit 201, but the main conversion circuit 201 according to this embodiment is a two-level three-phase full bridge circuit, and can be configured with six switching elements and six free wheel diodes connected in inverse parallel to each switching element. The semiconductor device 202 according to any one of the above-mentioned embodiments 1 to 3 is applied to at least one of the switching elements and free wheel diodes of the main conversion circuit 201. Two switching elements of the six switching elements are connected in series to configure upper and lower arms, and each upper and lower arm configures each phase (U phase, V phase, W phase) of the full bridge circuit. The output terminals of each upper and lower arm, i.e., the three output terminals of the main conversion circuit 201, are connected to the load 300.

[0073] The main conversion circuit 201 also includes a drive circuit (not shown) for driving each switching element, but the drive circuit may be built in the semiconductor device 202, or the semiconductor device 202 may include a drive circuit separately. The drive circuit generates drive signals for driving the switching elements of the main conversion circuit 201 and supplies them to the control electrodes of the switching elements of the main conversion circuit 201. Specifically, in accordance with a control signal from a control circuit 203 (described later), the drive circuit outputs to the control electrodes of each switching element a drive signal for turning the switching element on and a drive signal for turning the switching element off. When maintaining a switching element in the on state, the drive signal is a voltage signal (on signal) equal to or higher than the threshold voltage of the switching element, and when maintaining a switching element in the off state, the drive signal is a voltage signal (off signal) equal to or lower than the threshold voltage of the switching element.

[0074] The control circuit 203 controls the switching elements of the main conversion circuit 201 so that a desired power is supplied to the load 300. Specifically, the control circuit 203 calculates the time (on time) for each switching element of the main conversion circuit 201 to be in the on state based on the power to be supplied to the load 300. For example, the main conversion circuit 201 can be controlled by PWM control that modulates the on time of the switching elements according to the voltage to be output. Then, a control command (control signal) is output to a drive circuit provided in the main conversion circuit 201 so that an on signal is output to a switching element that should be in the on state at each time point, and an off signal is output to a switching element that should be in the off state. The drive circuit outputs an on signal or an off signal as a drive signal to the control electrode of each switching element according to this control signal.

[0075] In the power conversion device 200 according to the present embodiment, the semiconductor device 202 according to any one of the first to third embodiments is applied as a switching element and a free wheel diode of the main conversion circuit 201, so that a longer life can be achieved.

[0076] In the present embodiment, an example in which the semiconductor device 202 according to the first to third embodiments is applied to a two-level three-phase inverter has been described, but the application of the semiconductor device 202 according to the first to third embodiments is not limited to this, and the semiconductor device 202 can be applied to various power conversion devices. In the present embodiment, the two-level power conversion device is described, but the semiconductor device 202 according to the first to third embodiments may be applied to a three-level or multi-level power conversion device, and when power is supplied to a single-phase load, the semiconductor device 202 according to the first to third embodiments may be applied to a single-phase inverter. Furthermore, when power is supplied to a DC load or the like, the semiconductor device 202 according to the first to third embodiments can also be applied to a DC / DC converter or an AC / DC converter.

[0077] In addition, the power conversion device to which the semiconductor device 202 according to any one of the first to third embodiments is applied is not limited to the case where the load described above is an electric motor, but can also be used, for example, as a power supply device for an electric discharge machine, a laser processing machine, an induction heating cooker, or a non-contact power supply system, and can also be used as a power conditioner for a solar power generation system, a power storage system, or the like.

[0078] It should be noted that the embodiments can be freely combined, and each embodiment can be modified or omitted as appropriate.

[0079] Various aspects of the present disclosure are summarized below as appendices.

[0080] (Appendix 1) A substrate having an insulating layer and a conductive pattern formed on the insulating layer; a semiconductor element mounted on the conductive pattern; a frame-shaped case fixed to a peripheral portion of the substrate by an adhesive; A terminal attached to the case; and an internal wiring that connects the semiconductor element and the terminal, the case has a peripheral wall portion, a terminal installation portion that protrudes from the peripheral wall portion toward an inner periphery and in which the terminal is installed, and a board installation portion that protrudes downward from the terminal installation portion and faces an upper surface of the board, the conductive pattern is not formed on the peripheral portion of the substrate, and the insulating layer is exposed; the substrate placement portion and the insulating layer exposed at the peripheral portion of the substrate are fixed to each other by the adhesive; The substrate mounting portion is located directly below a connection portion of the terminal with the internal wiring.

[0081] (Appendix 2) a slit portion for accommodating the adhesive is formed in a portion of the case between the peripheral wall portion and the substrate installation portion, 2. The semiconductor device according to claim 1, wherein the slit portion includes an area in which the adhesive is not contained.

[0082] (Appendix 3) The case has four corners formed with screw holes, 3. The semiconductor device according to claim 1, wherein the screw holes are located on an outer periphery side of the substrate.

[0083] (Appendix 4) 4. The semiconductor device according to claim 1, wherein a contour shape of the substrate mounting portion is smaller than a contour shape of the terminal mounting portion.

[0084] (Appendix 5) 5. The semiconductor device according to claim 1, wherein a width of the tip of the substrate placement portion is smaller than a width of a portion other than the tip.

[0085] (Appendix 6) 6. The semiconductor device according to claim 1, wherein a rear surface of the substrate protrudes downward beyond a lower end of the case.

[0086] (Appendix 7) The semiconductor device according to any one of claims 1 to 6, wherein a portion of the substrate mounting portion facing the peripheral wall portion is formed in an inclined shape so as to move away from the peripheral wall portion toward the tip side of the substrate mounting portion.

[0087] (Appendix 8) 3. The semiconductor device according to claim 2, wherein a notch is formed directly above the slit in the terminal installation portion.

[0088] (Appendix 9) 9. The semiconductor device according to claim 1, wherein the insulating layer and the adhesive are made of a resin-based material.

[0089] (Appendix 10) 10. The semiconductor device according to claim 1, wherein the semiconductor element is made of a wide band gap semiconductor material.

[0090] (Appendix 11) 11. The semiconductor device of claim 10, wherein the wide band gap semiconductor material is any one of silicon carbide, a gallium nitride based material, or diamond.

[0091] (Appendix 12) A main conversion circuit having the semiconductor device according to any one of Supplementary Note 1 to Supplementary Note 11, which converts input power and outputs the power; a control circuit that outputs a control signal for controlling the main conversion circuit to the main conversion circuit; A power conversion device comprising: [Explanation of symbols]

[0092] 2 substrate, 4 insulating layer, 5 conductive pattern, 6 semiconductor element, 7 internal wiring, 9 resin case, 9a peripheral wall portion, 10 adhesive, 11 terminal, 13 screw hole, 20 terminal installation portion, 21 connection portion, 26 substrate installation portion, 27 slit portion, 40 tapered portion, 50 tapered portion, 60 cutout portion, 200 power conversion device, 201 main conversion circuit, 202 semiconductor device, 203 control circuit.

Claims

1. A substrate having an insulating layer and a conductive pattern formed on the insulating layer; a semiconductor element mounted on the conductive pattern; a frame-shaped case fixed to a peripheral portion of the substrate by an adhesive; A terminal attached to the case; and an internal wiring that connects the semiconductor element and the terminal, the case has a peripheral wall portion, a terminal installation portion that protrudes from the peripheral wall portion toward an inner periphery and in which the terminal is installed, and a board installation portion that protrudes downward from the terminal installation portion and faces an upper surface of the board, the conductive pattern is not formed on the peripheral portion of the substrate, and the insulating layer is exposed; the substrate placement portion and the insulating layer exposed at the peripheral portion of the substrate are fixed to each other by the adhesive; The substrate mounting portion is located directly below a connection portion of the terminal with the internal wiring.

2. a slit portion for accommodating the adhesive is formed in a portion of the case between the peripheral wall portion and the substrate installation portion, The semiconductor device according to claim 1 , wherein the slit portion includes an area in which the adhesive is not contained.

3. The case has four corners formed with screw holes, The semiconductor device according to claim 1 , wherein the screw holes are located on an outer periphery side of the substrate.

4. The semiconductor device according to claim 1 , wherein a contour shape of said substrate mounting portion is smaller than a contour shape of said terminal mounting portion.

5. The semiconductor device according to claim 1 , wherein a width of a tip end of said substrate placement portion is smaller than a width of a portion other than said tip end.

6. The semiconductor device according to claim 1 , wherein a rear surface of said substrate protrudes downward beyond a lower end of said case.

7. 2. The semiconductor device according to claim 1, wherein a portion of said substrate mounting portion facing said peripheral wall portion is formed in an inclined shape so as to become farther away from said peripheral wall portion toward a tip end side of said substrate mounting portion.

8. The semiconductor device according to claim 2 , wherein a notch is formed directly above said slit in said terminal installation portion.

9. The semiconductor device according to claim 1 , wherein said insulating layer and said adhesive are made of a resin-based material.

10. The semiconductor device according to claim 1 , wherein the semiconductor element is made of a wide band gap semiconductor material.

11. The semiconductor device according to claim 10 , wherein the wide band gap semiconductor material is any one of silicon carbide, a gallium nitride based material, and diamond.

12. A main conversion circuit having the semiconductor device according to any one of claims 1 to 11, which converts input power and outputs the converted power; a control circuit that outputs a control signal for controlling the main conversion circuit to the main conversion circuit; A power conversion device comprising:

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