Semiconductor device

Abstract

This semiconductor device comprises a first semiconductor element which comprises a first semiconductor, a second semiconductor element which comprises a second semiconductor having a band gap that is larger than that of the first semiconductor, a first electrode which is provided on one surface of the first semiconductor element and which is formed over the entire active region of the first semiconductor element and part of a termination region surrounding the periphery of the active region, a second electrode which is provided on one surface of the second semiconductor element and which is formed over the entire active region of the second semiconductor element and part of a termination region surrounding the periphery of the active region, a first conductor member which has a first junction portion electrically connected to the first electrode and a second junction portion electrically connected to the second electrode, and a second conductor member which is electrically connected to the other surface of each of the first semiconductor element and the second semiconductor element, wherein the shortest distance from an edge portion of the second electrode to the first conductor member is greater than the shortest distance from an edge portion of the first electrode to the first conductor member.

Description

Semiconductor Devices

[0001] The present invention relates to a semiconductor device.

[0002] semiconductor Ga ２ O ３ Semiconductor elements using this material are expected to be next-generation power devices. However, currently, only diodes can be fabricated using this material, and when used as a power module, it is necessary to combine it with a switching device fabricated from a different material, as described in Patent Document 1, for example.

[0003] International Publication No. 2023 / 190106

[0004] By the way, Ga ２ O ３ has a wider band gap than semiconductors such as Si, SiC, and GaN. ２ O ３ When a high voltage is applied to a power module using a diode chip, Ga ２ O ３ The electric field generated in the termination region of a diode chip is stronger than the electric field generated in the termination region of a switching device using semiconductors such as Si, SiC, GaN, etc. Therefore, dielectric breakdown of the insulating material between the chip and the conductor becomes an issue.

[0005] A semiconductor device according to an aspect of the present invention comprises: a first semiconductor element made of a first semiconductor; a second semiconductor element made of a second semiconductor having a band gap larger than that of the first semiconductor; a first electrode provided on one surface of the first semiconductor element and formed across the entire active region of the first semiconductor element and a portion of a termination region surrounding the active region; a second electrode provided on one surface of the second semiconductor element and formed across the entire active region of the second semiconductor element and a portion of a termination region surrounding the active region; a first conductor member having a first junction electrically connected to the first electrode and a second junction electrically connected to the second electrode; and a second conductor member electrically connected to the other surface of each of the first semiconductor element and the second semiconductor element, wherein the shortest distance from an end of the second electrode to the first conductor member is greater than the shortest distance from an end of the first electrode to the first conductor member.

[0006] According to the present invention, it is possible to improve the insulation resistance of a semiconductor device using a wide-gap semiconductor.

[0007] 9 is a diagram showing a power conversion device to which the semiconductor device of the present embodiment is applied. It is a diagram explaining a power module, where (a) is a plan view of the power module and (b) is a cross-sectional view taken along line A-A. It is a plan view of a semiconductor substrate used in a switching element and (b) is a cross-sectional view of a semiconductor substrate used in a diode element. It is a diagram showing modified example 1. It is a diagram showing modified example 2. It is a diagram showing modified example 3. It is a diagram showing a second embodiment of the present invention. It is a diagram showing modified example 4. It is a plan view of a power module in a third embodiment. It is a cross-sectional view taken along line B-B of FIG. 9. It is a cross-sectional view taken along line C-C of FIG. 9.

[0008] Hereinafter, an embodiment of a semiconductor device according to the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. Furthermore, in the following description, identical or similar elements and processes are given the same reference numerals, and duplicate explanations may be omitted. Note that the content described below merely shows one example of an embodiment of the present invention, and the present invention is not limited to the following embodiment, and can be implemented in various other forms.

[0009] 1 is a diagram showing a power conversion device to which a semiconductor device according to the present embodiment is applied. In the example shown in Fig. 1, a power conversion device 20 drives an electric motor 30 mounted on a vehicle 1000. The vehicle 1000 is provided with a power storage device 10, and the power conversion device 20 converts DC power supplied from the power storage device 10 into AC power to drive the electric motor 30.

[0010] The electric motor 30 is, for example, a traction motor for rotating wheels. The electric motor 30 has three-phase coils that are connected in a predetermined pattern. The connection pattern is not limited to the Y-pattern shown in FIG. 1 , and other connection patterns such as a delta pattern may also be used. The electric motor 30 is driven to rotate by applying a predetermined current pattern from the power conversion device 20 to the three-phase coils.

[0011] The power storage device 10 has a positive electrode terminal 10a and a negative electrode terminal 10b. The power conversion device 20 has a positive electrode bus line 21p, a negative electrode bus line 21n, a smoothing capacitor 11, and three-phase switching arms 50 (U, V, W). The positive electrode bus line 21p is connected to the positive electrode terminal 10a of the power storage device 10. The negative electrode bus line 21n is connected to the negative electrode terminal 10b of the power storage device 10. Both ends of the smoothing capacitor 11 and the three-phase switching arms 50 (U, V, W) are connected to the positive electrode bus line 21p and the negative electrode bus line 21n.

[0012] Each of the three-phase switching arms 50 (U, V, W) is provided with an upper arm power module 70A and a lower arm power module 70B. The upper arm power module 70A and the lower arm power module 70B each include a switching element 701 and a diode 702.

[0013] The upper arm power module 70A and the lower arm power module 70B are connected in series. A connection point between the upper arm power module 70A and the lower arm power module 70B is connected to one end of the coil of the corresponding phase of the electric motor 30. In the example shown in Fig. 1, one switching element is provided for each of the upper and lower arms, but a configuration in which multiple switching elements are used in parallel may also be used.

[0014] The power conversion device 20 includes a control circuit 40 that controls the gate drive devices 60A and 60B. The control circuit 40 outputs PWM control commands P1 and P2 to the gate drive devices 60A and 60B to individually control the upper-arm and lower-arm switching elements 701. The control circuit 40 includes, for example, a CPU, RAM, ROM, and a communication circuit. The PWM control commands P1 and P2 are pulse signals having a predetermined pulse width, and the control circuit 40 PWM-controls the switching elements 701. The PWM control commands P1 and P2 alternately turn on and off the switching elements 701 of the upper and lower arms of the same phase, so long as they are not turned on simultaneously. As a result, DC power from the power storage device 10 is converted into AC power, which drives and rotates the electric motor 30.

[0015] In this embodiment, the power conversion device 20 constituting an inverter as shown in FIG. 1 will be described as an example, but the semiconductor device (power module) of the present invention is not limited to this and can also be applied to a DC / DC converter, an AC / AC converter, an AC / DC inverter, etc.

[0016] FIG. 2 illustrates a power module 70, with (a) showing a plan view of the power module 70 and (b) showing a cross section taken along the line A-A in (a). Note that in (a), the conductor plate 140 (described later) is represented by an imaginary line (two-dot chain line) and is not shown. The power module 70 includes a semiconductor chip 110 of a switching element 701, a semiconductor chip 120 of a diode 702, a conductor member 13, a conductor member 14, a gate wire 150, a source sense wire 151, a gate conductor plate 160, and a source sense conductor plate 161. Note that when multiple pairs of semiconductor chips 110, 120 are provided in the power module 70, the semiconductor chips 110 and the semiconductor chips 120 are at the same potential. In the example shown in FIG. 2, the conductor member 13 is a plate-shaped member. Meanwhile, the conductor member 14 includes a plate-shaped conductor plate 140 and bonding protrusions 141, 142 protruding from one surface of the conductor plate 140.

[0017] The semiconductor substrate 111 of the semiconductor chip 110 of the switching element 701 (see FIG. 1) is formed of a semiconductor such as Si, SiC, or GaN. A first main electrode 112 is formed on one surface (the lower surface in the A-A cross-sectional view) of the semiconductor substrate 111. A second main electrode 113, a first control electrode 114, and a second control electrode 115 are formed on the other surface (the upper surface in the A-A cross-sectional view) of the semiconductor substrate 111.

[0018] The first main electrode 112 is joined to the conductor member 13 via a conductive joining member (not shown). The second main electrode 113 is joined to the top of a joining protrusion 141 protruding from the conductor plate 140 via a conductive joining member (not shown). The first control electrode 114 is electrically connected to a gate conductor plate 160 by a gate wire 150. The second control electrode 115 is electrically connected to a source sense conductor plate 161 by a source sense wire 151. Note that the second control electrode 115 may not be formed.

[0019] The semiconductor substrate 121 of the semiconductor chip 120 of the diode 702 is, for example, Ga ２ O ３ The semiconductor substrate 121 is made of a semiconductor. A first main electrode 122 is formed on one surface (the lower surface in the A-A cross-sectional view) of the semiconductor substrate 121. A second main electrode 123 is formed on the other surface (the upper surface in the A-A cross-sectional view) of the semiconductor substrate 121. The first main electrode 122 is bonded to the conductor member 13 via a conductive bonding member (not shown). The second main electrode 123 is bonded to the top of a bonding protrusion 142 protruding from the conductor plate 140 via a conductive bonding member (not shown).

[0020] The first main electrodes 112, 122, the second main electrodes 113, 123, the first control electrode 114, and the second control electrode 115 are formed by laminating any of Ni, Ti, W, Al, Ag, Ag, and Au, with the outermost surface made of, for example, Ni, Cu, Ag, or Au. The gate wire 150 and the source sense wire 151 are made of, for example, Al, Cu, or a compound containing these. The conductor members 13, 14, the gate conductor plate 160, and the source sense conductor plate 161 are made of, for example, Ni-plated Cu, and are electrically insulated from each other. The conductive bonding material that bonds the main electrodes 112, 113, 122, and 123 of the semiconductor chips 110, 120 to the conductor members 13, 14 is, for example, solder or a sintered material.

[0021] FIG. 3 is a plan view of semiconductor substrates 111 and 121. The semiconductor chip 110 has a structure in which a current flows between main electrodes 112 and 113. As shown in FIG. 3( a), an active region 116 and a termination region 117 formed to surround the active region 116 are present on the second main electrode 113 side of the semiconductor substrate 111. The active region 116 is a region through which a current flows. The termination region 117 is a region through which no current flows and which becomes a high electric field when a high voltage is applied. The second main electrode 113 and the second control electrode 115 shown in FIG. 2 are formed in the active region 116. The second main electrode 113 is formed so that its edge region overlaps a portion of the termination region 117. Furthermore, a first control electrode 114 is formed in a gate region 118 provided so as to be surrounded by the termination region 117.

[0022] The semiconductor chip 120 has a structure in which a current flows between main electrodes 122 and 123. As shown in FIG. 3B, on the second main electrode 123 side of the semiconductor substrate 121, there are an active region 126 through which a current flows, and a termination region 127 formed to surround the active region 126 and in which no current flows and which becomes a high electric field when a high voltage is applied. The second main electrode 123 shown in FIG. 2 is formed in the active region 126. The second main electrode 123 is provided so that its edge region overlaps a part of the termination region 127.

[0023] Returning to FIG. 2 , a resin material 119 is applied to the termination region 117 of the semiconductor substrate 111. The resin material 119 is applied so as to cover the edge of the second main electrode 113. Similarly, a resin material 129 is applied to the termination region 127 of the semiconductor substrate 121. The resin material 129 is applied so as to cover the edge of the second main electrode 123. The resin materials 119 and 129 function as a protective film for alleviating the electric field and preventing foreign matter. Note that the resin materials 119 and 129 are not shown in FIG. 2( a).

[0024] The area of ​​the bonding surfaces of the bonding protrusions 141, 142 provided on the conductive member 14 (i.e., the cross section of the bonding protrusions 141, 142) is generally set smaller than the area of ​​the second main electrodes 113, 123. By using the structure shown in Figure 2, an appropriate insulation distance can be provided between the termination regions 117, 127 of the semiconductor chips 110, 120 and the second conductive member 14, thereby suppressing dielectric breakdown of the semiconductor chips 110, 120 due to discharge. Dielectric breakdown here refers to breakdown that begins with breakdown of the insulating material (resin materials 119, 129) formed on the upper part of the semiconductor chips 110, 120.

[0025] By the way, Ga ２ O ３ Unlike semiconductors such as Si, SiC, and GaN, it is difficult to form a p-type semiconductor in Ga, and therefore it is more difficult to alleviate the electric field in the termination region than in semiconductors such as Si, SiC, and GaN. ２ O ３ In the semiconductor chip 120 formed by the above-mentioned method, the strength of the electric field generated in the termination region when a high voltage is applied is greater than that in the case of the semiconductor chip 110 formed by a semiconductor such as Si, SiC, or GaN. The electric field strength is strongest near the end of the second main electrode 123 of the semiconductor chip 120. In this embodiment, the shortest distance between the end of the second main electrode 123 of the semiconductor chip 120 and the conductor member 14 is set longer than the shortest distance between the end of the second main electrode 113 of the semiconductor chip 110 and the conductor member 14, thereby mitigating the electric field strength in the semiconductor chip 120.

[0026] The location that is the target of the shortest distance between the main electrode end and the conductor member 14 is the target of various directions with respect to the main electrode end. In the conductor member 14 having the bonding protrusions 141, 142 as shown in FIG. 2 , the conductor plate 140 or the bonding protrusions 141, 142 can be the target of the shortest distance with respect to the main electrode end. In the example shown in FIG. 2 , the protruding height (z-direction dimension) of the bonding protrusions 141, 142 is large, so in the semiconductor chip 110, the x-direction distance d1 between the end of the second main electrode 113 and the bonding protrusion 141 is the shortest distance. Similarly, in the semiconductor chip 120, the x-direction distance d2 between the end of the second main electrode 123 and the bonding protrusion 142 is the shortest distance.

[0027] The Ga used in the semiconductor substrate 121 of the semiconductor chip 120 ２ O ３ has a larger band gap and a larger electric field strength at the end of the main electrode than semiconductors such as Si, SiC, and GaN used in the semiconductor substrate 111 of the semiconductor chip 110. In the example shown in FIG. 2, by setting d2>d1 as described above, the electric field strength on the semiconductor chip 120 side is alleviated.

[0028] For example, in a configuration where d2=d1 is set, unlike the present embodiment, it is possible to set d1 and d2 large in order to alleviate the electric field strength on the side of the semiconductor chip 120. However, if d1 and d2 are set large, the cross-sectional area of ​​the bonding protrusions 141 and 142 becomes small, which causes a problem of increasing the thermal resistance on the side of the semiconductor chip 110, which is the switching element.

[0029] On the other hand, in this embodiment, by setting d2 > d1, the shortest distance to the conductor member 14 on the semiconductor chip 120 side is made longer than the shortest distance to the conductor member 14 on the semiconductor chip 110 side, thereby alleviating the electric field strength on the semiconductor chip 120 side. This makes it possible to make the insulation resistance on the semiconductor chip 120 side the same as that on the semiconductor chip 110 side, and it is possible to reduce the thermal resistance of the joint protrusion 141 on the semiconductor chip 110 side while suppressing discharge on the semiconductor chip 120 side. As a result, the insulation resistance of the power module 70 is increased and the output density is improved, making it possible to provide a highly reliable, low-loss, and compact power module.

[0030] (Variation 1) FIG. 4 is a diagram showing Variation 1. In the example shown in FIG. 2 , the shortest distance between the ends of the second main electrodes 113, 123 and the conductor member 14 was the x-direction distance. On the other hand, Variation 1 shows a case where the z-direction distance is the shortest distance. The protruding height of the joint convex portions 141, 142 is set smaller than in the case of FIG. 2 , and the z-direction distances d3, d4 are the shortest distances between the ends of the second main electrodes 113, 123 and the conductor plate 140. Here, the z-direction distance d3 is the distance from the end of the second main electrode 113 to the region 140a of the conductor plate 140, and the z-direction distance d4 is the distance from the end of the second main electrode 123 to the region 140b of the conductor plate 140.

[0031] In the conductive member 14, the protruding heights of the joint protrusions 141 and 142 are d3 and d4, respectively (d4 > d3). The conductive plate 140, which has a uniform thickness, has a stepped shape such that the region 140a is closer to the semiconductor chip 110 than the region 140b. In the first modification, the z-direction distances d3 and d4, which are the shortest distances, are set so that d4 > d3, so that the electric field strength on the semiconductor chip 120 side can be alleviated, as in the configuration of FIG. 2. This ensures insulation reliability and leads to a longer product life.

[0032] Furthermore, since the protruding height of the joint protrusion 141 can be made shorter than that of the joint protrusion 142, it is possible to provide low thermal resistance on the semiconductor chip 110 side. As a result, it is possible to increase the output density of the semiconductor chip 110, making it possible to reduce the size of the power module 70, and providing an inverter with high output density.

[0033] (Variation 2) FIG. 5 is a diagram showing Variation 2. In Variation 2, the conductor member 13 has a joint protrusion 131 formed on one surface (the surface facing the semiconductor chip 110) of a flat conductor plate 130. The conductor plate 140 of the conductor member 14 is also flat. The rest of the configuration is the same as in Variation 1 ( FIG. 4 ). In Variation 2, the joint protrusion 131 is formed on the conductor member 13, and the z-direction position of the semiconductor chip 110 is raised above the semiconductor chip 120 (toward the conductor member 14). With this configuration, the shortest distance between the conductor member 14 and the semiconductor chips 110 and 120 is set to the z-direction distances d3 and d4 (d4 > d3) similar to the case of FIG. 4 .

[0034] In this way, in Modification 2, the z-direction distances d3 and d4, which are the shortest distances, are set so that d4 > d3, so that the electric field strength on the semiconductor chip 120 side can be alleviated. Furthermore, by forming the joint protrusion 131, the protruding height of the joint protrusion 141 can be made shorter than that of the joint protrusion 142, and the thermal resistance on the semiconductor chip 110 side can be made low. Therefore, the power density of the semiconductor chip 110 can be increased, the power module 70 can be made smaller, and an inverter with a high power density can be provided.

[0035] Incidentally, surfaces 13S, 14S of the conductor members 13, 14 opposite to the semiconductor chip bonding side function as heat dissipation surfaces, and a cooling mechanism 200 is disposed on the heat dissipation surfaces 13S, 14S as shown by the two-dot chain line in Fig. 5. Therefore, if the heat dissipation surface 14S side has a stepped shape as in the conductor plate 140 of Modification 1, it is difficult to achieve good thermal contact with the cooling mechanism 200. On the other hand, in Modification 2, the heat dissipation surfaces 13S, 14S are flat surfaces without any steps, which makes it easy to achieve good thermal contact with the cooling mechanism 200.

[0036] (Variation 3) Fig. 6 is a diagram showing Variation 3. In Variation 3, the conductor plate 140 is made up of a region 140c with a thickness t1 and a region 140d with a thickness t2. The conductor plate 140 is disposed so that the region 140c faces the semiconductor chip 110, and the region 140d faces the semiconductor chip 120. A bonding protrusion 141 with a height d3 that is bonded to the second main electrode 113 of the semiconductor chip 110 is formed on the surface of the region 140c that faces the semiconductor chip 110. A bonding protrusion 142 with a height d4 that is bonded to the second main electrode 123 of the semiconductor chip 120 is formed on the surface of the region 140d that faces the semiconductor chip 120.

[0037] The heights d3 and d4 are set such that d4 > d3. Therefore, the shortest distance (height d4) between the end of the second main electrode 123 and the conductor member 14 can be made greater than the shortest distance (height d3) between the end of the second main electrode 113 and the conductor member 14. As a result, the electric field strength on the semiconductor chip 120 side can be alleviated, ensuring insulation reliability and leading to a longer product life. Furthermore, the thicker the region 140c, the lower the height of the bonding protrusion 141 can be, thereby further reducing the thermal resistance on the semiconductor chip 110 side and further improving the power density of the semiconductor chip 110. As a result, the power module 70 can be miniaturized, making it possible to provide an inverter with a high power density.

[0038] Furthermore, by forming a stepped surface where the plate thickness changes on the semiconductor chip 110, 120 side of the conductor plate 140, the heat dissipation surface 14S can be made flat, which makes it easier to achieve good thermal contact when arranging the cooling mechanism 200 (see Figure 5).

[0039] Second Embodiment FIG. 7 is a diagram illustrating a second embodiment of the present invention. The power module 800 illustrated in FIG. 7 illustrates an example of a power module 70 having a double-sided cooling structure, in which a heat sink serving as a cooling mechanism is provided. When the power module 70 is actually used, it is configured to include the cooling mechanism and sealing structure of this embodiment. The following description will be given using the cooling mechanism of this embodiment as an example, where it is applied to the power module 70 shown in FIG. 5 . However, the cooling mechanism of this embodiment can also be applied to the other forms of power module 70 described above. The following description will be omitted regarding the configuration of the power module 70 shown in FIG. 5 , except for the different components.

[0040] Heat dissipation materials 802 are bonded to the heat dissipation surfaces 13S, 14S of the conductor members 13, 14 using bonding materials 801. The heat dissipation materials 802 are formed, for example, from ceramics or resin, and electrically insulate the heat sinks 804 from the conductor members 13, 14. A heat sink 804 is disposed on the surface of each heat dissipation material 802 via a heat-conductive intermediate material 803. The intermediate material 803 is provided to improve adhesion between the heat dissipation material 802 and the heat sink 804. The intermediate material 803 is formed, for example, from a metal, a resin, a carbon sheet, or a compound thereof, or by laminating these materials. Note that, although the heat dissipation material 802 is bonded using bonding materials 801 here, the heat dissipation material 802 may also be bonded directly to the heat dissipation surfaces 13S, 14S without using bonding materials 801.

[0041] To prevent discharge when a high voltage is applied, a sealant 805 made of insulating resin is filled in the gap between the heat dissipation material 802 on the conductor member 14 side and the heat dissipation material 802 on the conductor member 13 side, and the power module components are sealed with the sealant 805. The sealant 805 is formed, for example, by silicone gel or transfer molding. The conductor members 13 and 14 have connection terminals 133 and 144 that can be electrically connected to other components. The connection terminals 133 and 144 are exposed to the outside of the sealant 805. Although not shown, the portions to which other components, such as the gate conductor plate 160 and the source sense conductor plate 161 shown in FIG. 2, are connected may not be sealed with the sealant 805.

[0042] The heat sink 804 is formed of, for example, Cu, Al, or the like, and includes a refrigerant flow path 804a through which a refrigerant (cooling liquid or air) flows. Heat transferred from the semiconductor chips 110, 120 to the heat sink 804 is dissipated to the refrigerant flowing through the refrigerant flow path 804a. In this way, by adopting a double-sided cooling structure in which the heat sinks 804 are disposed on the heat dissipation surfaces 13S, 14S of the conductor members 13, 14, respectively, heat generated in the semiconductor chips 110, 120 is dissipated by the radiators 804 on the top and bottom as shown. As a result, the output density of the power module 800 can be increased, and the power module 800 can also be made more compact.

[0043] (Variation 4) FIG. 8 is a diagram illustrating a variation (variation 4) of the second embodiment. In the power module 810 illustrated in FIG. 8 , a resin material 229 is disposed so as to cover the end of the second main electrode 123 and the resin material 129 provided on the termination region 127, in addition to the configuration of the power module 800 illustrated in FIG. 7 . The resin material 229 has a higher dielectric constant than the resin material 129 and the sealing material 805. The other configurations are the same as those of the power module 800 illustrated in FIG. 7 . By covering the end of the second main electrode 123 and the resin material 129 on the termination region of the semiconductor substrate 121 with the resin material 229 having a higher dielectric constant, the strength of the electric field formed near the end of the second main electrode 123 and the termination region is further reduced. As a result, the insulation reliability of the power module 810 is further improved, leading to a longer life of the power module 810.

[0044] (Third Embodiment) Figures 9 to 11 are diagrams illustrating a third embodiment of the present invention. The power module 820 shown in Figure 9 is a half-bridge module formed using two of the power modules 70 shown in Figure 2 of the first embodiment. The power module 820 includes the upper arm power module 70A and the lower arm power module 70B shown in Figure 1. Note that the upper arm power module 70A and the lower arm power module 70B are provided with heat dissipation materials, intermediate materials, heat sinks, and sealing materials, as in the case of the power module 800 in Figure 7, but these are not shown in Figures 9 to 11.

[0045] Fig. 9 is a plan view of the power module 820. In Fig. 9, the conductor member 14A of the upper arm power module 70A and the conductor member 14B of the lower arm power module 70B are represented by imaginary lines (two-dot chain lines) as in Fig. 2, and are not shown. Fig. 10 is a cross-sectional view taken along line B-B in Fig. 9. Fig. 11 is a cross-sectional view taken along line C-C in Fig. 9.

[0046] The conductor member 13A of the upper arm power module 70A has a connection terminal portion 721 as the P terminal of the half-bridge module. The conductor member 13B of the lower arm power module 70B has a connection terminal portion 722 as the intermediate terminal of the half-bridge module. Furthermore, the power module 820 has a conductor plate 723 that is electrically insulated from the conductor members 13A and 13B as the N terminal of the half-bridge module.

[0047] As shown in Fig. 10, the conductor member 14A of the upper arm power module 70A has a connection region 145 extending downward from the conductor plate 140A. The lower end of the connection region 145 is connected to the conductor member 13B of the lower arm power module 70B. This electrically connects the conductor member 14A of the upper arm power module 70A to the conductor member 13B of the lower arm power module 70B. In other words, this connection structure corresponds to the series connection of the upper arm power module 70A and the lower arm power module 70B in Fig. 1.

[0048] 11 , the conductor member 14B of the lower arm power module 70B includes a connection region 146 extending downward from the conductor plate 140B. The lower end of the connection region 146 is connected to the conductor plate 723 serving as the N terminal of the half-bridge module. For example, solder or a sintered material is used to connect the connection region 145 to the conductor member 13B and the connection region 146 to the conductor plate 723. As described above, according to the third embodiment, it is possible to provide a half-bridge power module 820 with excellent insulation resistance.

[0049] According to the embodiment and modified examples of the present invention described above, the following advantageous effects are achieved.

[0050] (1) As shown in FIGS. 2 and 3, the power module 70 is a semiconductor device that includes a semiconductor chip 110 made of a first semiconductor such as Si and a Ga semiconductor chip 110 having a larger band gap than the first semiconductor. ２ O ３a second main electrode 113 provided on one side of the semiconductor chip 110 and formed over the entire active region 116 of the semiconductor chip 110 and a portion of the termination region 117 surrounding the periphery of the active region 116; a second main electrode 123 provided on one side of the semiconductor chip 120 and formed over the entire active region 126 of the semiconductor chip 120 and a portion of the termination region 127 surrounding the periphery of the active region 126; a conductor member 14 having a bonding protrusion (first bonding portion) 141 electrically bonded to the second main electrode 113 and a bonding protrusion (second bonding portion) 142 electrically bonded to the second main electrode 123; and a conductor member 13 electrically bonded to the other side of each of the semiconductor chip 110 and the semiconductor chip 120. The shortest distance d2 from the end of the second main electrode 123 to the conductive member 14 is greater than the shortest distance d1 from the end of the second main electrode 113 to the conductive member 14 .

[0051] As described above, by configuring the shortest distance d1, d2 so that d2>d1, a semiconductor Ga ２ O ３ This allows the electric field strength in the semiconductor chip 120 to be reduced. This makes it possible to make the insulation resistance of the semiconductor chip 120 comparable to that of the semiconductor chip 110, thereby improving the insulation resistance of the power module 70. In the above-described embodiment, the wide bandgap semiconductor is a Ga semiconductor. ２ O ３ However, other materials such as diamond, AlN, and GeO ２ The present invention can be similarly applied to the case where other wide band gap semiconductors such as those mentioned above are used.

[0052] 4 and other figures, the conductor member 14 includes a conductor plate 140, a joint protrusion 141 protruding from the conductor plate 140, and a joint protrusion 142 protruding from the conductor plate 140 and having a higher protrusion height than the joint protrusion 141, and the shortest distance d4 between the end of the second main electrode 123 and the conductor plate 140 (region 140b) is greater than the shortest distance d3 between the end of the second main electrode 113 and the conductor plate 140 (region 140a). This reduces the electric field strength on the semiconductor chip 120 side, ensuring insulation reliability and extending the product life.

[0053] Furthermore, since the protruding height of the joint convex portion 141 can be shortened, it is possible to reduce the thermal resistance on the semiconductor chip 110 side. As a result, it is possible to increase the output density of the semiconductor chip 110, making it possible to reduce the size of the power module 70, and to provide an inverter with a high output density.

[0054] (3) In the above (2), as shown in Fig. 5 etc., the conductor plate 140 is a flat member, and the conductor member 13 includes a flat conductor plate 130 to which the semiconductor chip 120 is electrically joined, and a joint protrusion 131 that protrudes from the conductor plate 130 toward the semiconductor chip 110 and to which the semiconductor chip 110 is electrically joined. With this configuration, in addition to the effect described in the above (2), a cooling mechanism such as a heat sink can be disposed on the flat conductor plates 130, 140 with good thermal contact.

[0055] (4) In (2) above, as shown in Figure 6, etc., the conductor member 14 has a first region 140c having a first plate thickness t1 and provided with a joint protrusion 141, and a second region 140d having a second plate thickness t2 thinner than the plate thickness t1 and provided with a joint protrusion 142, and the shortest distance d4 between the end of the second main electrode 123 and the second region 140d is greater than the shortest distance d3 between the end of the second main electrode 113 and the first region 140c.

[0056] By making the shortest distances d3 and d4 such that d4 > d3 with the above configuration, it is possible to alleviate the electric field strength on the semiconductor chip 120 side and reduce the thermal resistance on the semiconductor chip 110 side. Furthermore, by making the region 140d thinner than the region 140c, the height of the joint protrusion 141 can be made lower, thereby further improving the output density of the semiconductor chip 110. As a result, it is possible to miniaturize the power module 70, and it is possible to provide an inverter with a high output density.

[0057] 7 and the like, the power module 800 further includes an electrically insulating first heat dissipation material 802 provided on the heat dissipation surface 14S of the conductor member 14, a heat sink 804 provided on the first heat dissipation material 802 with a heat conductive intermediate material 803 interposed therebetween, an electrically insulating second heat dissipation material 802 provided on the heat dissipation surface 13S of the conductor member 13, a heat sink 804 provided on the second heat dissipation material 802 with a heat conductive intermediate material 803 interposed therebetween, and a resin sealing material 805 that fills gaps between the semiconductor chip 110, the semiconductor chip 120, the conductor member 14, and the conductor member 13 and seals the power module components (semiconductor device components) disposed between the first heat dissipation material 802 and the second heat dissipation material 802 to seal the power module components. This configuration allows the power module 800 to be a double-sided cooling structure module with excellent insulation resistance.

[0058] (6) In the above (5), as shown in Figure 8 and other figures, a resin material 229 having a higher dielectric constant than the sealing material 805 is provided, and is disposed between the termination region 127 of the semiconductor chip 120 and the sealing material 805. By providing the high-dielectric-constant resin material 229 between the termination region 127 and the sealing material 805 in this way, the strength of the electric field formed near the end of the second main electrode 123 and the termination region 127 is further reduced.

[0059] (7) As shown in Figures 9 to 11, etc., a power module 820 is a power module in a half-bridge configuration having an upper arm power module 70A and a lower arm power module 70B, each configured by the power module 70 described in (1) above. The power module 820 includes a conductor plate 723 in which the conductor member 14A of the upper arm power module 70A is connected to the conductor member 13B of the lower arm power module 70B, and which is electrically independent from the conductor member 14A and the conductor member 13A of the upper arm power module 70A and the conductor member 13B of the lower arm power module 70B, and which is electrically connected to the conductor member 14B of the lower arm power module 70B.

[0060] The above-described embodiments and various modifications are merely examples, and the present invention is not limited to these, as long as the features of the invention are not impaired. Other embodiments that can be conceived within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention.

[0061] 10... Energy storage device, 13, 13A, 13B, 14, 14A, 14B... Conductor member, 20... Power conversion device, 30... Electric motor, 50... Three-phase switching arm, 70, 800, 810, 820... Power module, 70A... Upper arm power module, 70B... Lower arm power module, 110, 120... Semiconductor chip, 111, 121... Semiconductor substrate, 112, 122... First main electrode, 113, 123... Second main electrode, 114, 115... Control electrode, 116, 126... Active region, 117, 127 ...termination region, 118...gate region, 119, 129, 229...resin material, 130, 140, 140A, 140B, 723...conductor plate, 131, 141, 142...bonding protrusion, 133, 144...connection terminal, 140a to 140d...region, 143...protrusion, 145, 146...connection region, 145, 146...connection region, 200...cooling mechanism, 701...switching element, 702...diode, 721, 722...connection terminal, 801...bonding material, 802...heat dissipation material, 803...intermediate material, 804...heat sink, 805...sealing material

Claims

a first electrode provided on one surface of the first semiconductor element, the first electrode extending over the entire active region of the first semiconductor element and a portion of a termination region surrounding the active region; a second electrode provided on one surface of the second semiconductor element, the second electrode extending over the entire active region of the second semiconductor element and a portion of a termination region surrounding the active region; a first conductor member having a first junction electrically connected to the first electrode and a second junction electrically connected to the second electrode; and a second conductor member electrically connected to the other surface of each of the first semiconductor element and the second semiconductor element, wherein the shortest distance from an end of the second electrode to the first conductor member is greater than the shortest distance from an end of the first electrode to the first conductor member.

2. A semiconductor device according to claim 1, wherein the first conductive member comprises: a first conductive plate; the first joint portion, which is a first convex portion protruding from the first conductive plate; and the second joint portion, which is a second convex portion protruding from the first conductive plate and having a higher protrusion height than the first convex portion; and the shortest distance between the end of the second electrode and the first conductive plate is greater than the shortest distance between the end of the first electrode and the first conductive plate.

3. A semiconductor device according to claim 2, wherein the first conductor plate is a flat member, and the second conductor member comprises: a flat second conductor plate to which the second semiconductor element is electrically joined; and a third protrusion that protrudes from the second conductor plate in the direction of the first semiconductor element and to which the first semiconductor element is electrically joined.

4. A semiconductor device according to claim 2, wherein the first conductive plate has a first thickness and comprises a first region in which the first protrusion is provided, and a second region in which the second protrusion is provided and a second thickness thinner than the first thickness, and wherein the shortest distance between the end of the second electrode and the second region is greater than the shortest distance between the end of the first electrode and the first region.

5. A semiconductor device according to claim 1, comprising: an electrically insulating first heat dissipation material provided on the heat dissipation surface of the first conductive member; a first heat sink provided on the first heat dissipation material via a first heat transfer material; an electrically insulating second heat dissipation material provided on the heat dissipation surface of the second conductive member; a second heat sink provided on the second heat dissipation material via a second heat transfer material; and a resin sealing material that fills gaps between the first heat dissipation material and the second heat dissipation material, which are semiconductor device components arranged between the first heat dissipation material and the second heat dissipation material, and seals the semiconductor device components.

6. A semiconductor device according to claim 5, further comprising a resin material disposed between the termination region of the second semiconductor element and the resin sealing material, the resin material having a higher dielectric constant than the resin sealing material.

7. A semiconductor device in a half-bridge configuration having an upper arm power module and a lower arm power module each constructed by the semiconductor device described in claim 1, wherein the first conductor member of the upper arm power module is connected to the second conductor member of the lower arm power module, and the semiconductor device comprises a third conductor member that is electrically independent from the first and second conductor members of the upper arm power module and the second conductor member of the lower arm power module, and is electrically connected to the first conductor member of the lower arm power module.

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