Semiconductor device and power conversion device

Abstract

Semiconductor device, comprising: an insulating layer (3); a circuit structure (4) arranged on an upper surface of the insulating layer (3); a semiconductor element (5) which is bonded to an upper surface of the circuit structure (4) by a first bonding material (7a); an insulating component (6) which is bonded to the upper surface of the circuit structure (4) by a second bonding material (7b); and a lead electrode (9) that connects the semiconductor element (5) to the insulating component (6), wherein an upper surface of the semiconductor element (5) is bonded to a lower surface of the lead electrode (9) by a third bonding material (7c), an upper surface of the insulating component (6) is bonded to the lower surface of the lead electrode (9) by a fourth bonding material (7d) and the first bonding material (7a), the second bonding material (7b), the third bonding material (7c) and the fourth bonding material (7d) consist of the same material, characterized by the fact that an insulating layer (23) that is different from the insulating layer (3); and a circuit structure (24) that is different from the circuit structure (4), wherein the different circuit structure (24) is arranged on a lower surface of the different insulating layer (23), wherein the various circuit structure (24) is arranged above the supply electrode (9), a sub-area of ​​the upper surface of the lead electrode (9), to which the semiconductor element (5) is bonded, and a sub-area of ​​the upper surface of the lead electrode (9), to which the insulating component (6) is bonded, are bonded to the various circuit structures (24) respectively by a fifth bonding material (7e) and a sixth bonding material (7f). the first bonding material (7a), the second bonding material (7b), the third bonding material (7c), the fourth bonding material (7d), the fifth bonding material (7e) and the sixth bonding material (7f) are made of the same material.

Description

BACKGROUND OF THE INVENTION Area of ​​the invention

[0001] The present disclosure relates to a semiconductor device and a power conversion device. Description of the background technology

[0002] It is desirable to improve the heat dissipation of semiconductor elements and lead electrodes in semiconductor devices due to the increase in current capacity in the semiconductor devices.

[0003] WO 2017 / 130 370 A1, for example, discloses a semiconductor device comprising: a semiconductor element; a lead electrode with one end of a lower surface connected to an upper surface of the semiconductor element; a cooling mechanism arranged via a heat spreader on the lower surface of the semiconductor element; and a heat dissipation block arranged in thermal connection between the cooling mechanism and another end of the lower surface of the lead electrode. This structure improves the heat dissipation of the semiconductor element and the lead electrode without increasing the product size.

[0004] However, according to the technology described in WO 2017 / 130 370 A1, if the overall height of the heat dissipation block differs slightly from the overall height of the semiconductor element, the solder, the heat spreader, and the lead electrode, a component within the semiconductor element that is relatively susceptible to deformation will be deformed. If an insulating layer located beneath the heat dissipation block is deformed and dielectric breakdown occurs, the semiconductor device will malfunction.

[0005] Further semiconductor devices are known from JP 2017 - 5 129 A and JP 2007 - 184 525 A. SUMMARY

[0006] The objective of the present disclosure is to provide a technology to enable a reduction of the voltage applied or exerted on an insulating component and an improvement in the reliability in a semiconductor device.

[0007] This problem is solved by the features of the dependent claims. The sub-claims describe advantageous embodiments of the invention.

[0008] A semiconductor device according to partial aspects of the present disclosure comprises an insulating layer, a circuit structure, a semiconductor element, an insulating component, and a lead electrode. The circuit structure is arranged on an upper surface of the insulating layer. The semiconductor element is bonded to an upper surface of the circuit structure by a first bonding material. The insulating component is bonded to the upper surface of the circuit structure by a second bonding material. The lead electrode connects the semiconductor element to the insulating component. An upper surface of the semiconductor element is bonded to a lower surface of the lead electrode by a third bonding material. An upper surface of the insulating component is bonded to the lower surface of the lead electrode by a fourth bonding material.The first bonding material, the second bonding material, the third bonding material and the fourth bonding material consist of the same material.

[0009] Adjusting the thickness of the second bonding material to bond the insulating component to the upper surface of the circuit structure, and the thickness of the fourth bonding material to bond the upper surface of the insulating component to the lower surface of the lead electrode, can reduce the voltage exerted on the insulating component.

[0010] Since the first, second, third, and fourth bonding materials are made of the same material, the heating times required for bonding can be reduced. This prevents heat damage to the semiconductor device components and improves the reliability of the device.

[0011] These and other objectives, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when it is taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is defined in the main claim and the dependent claim. The dependent claims describe advantageous embodiments of the invention. Aspects of the present invention defined in the claims are explained below with reference to the figures and embodiments. Fig. Figure 1 schematically illustrates a cross-sectional view of a semiconductor device according to embodiment 1; Fig. Figure 2 schematically illustrates a top view of the semiconductor device according to embodiment 1, looking down at a lead electrode contained in the semiconductor device; Fig. Figure 3 schematically illustrates a cross-sectional view of a semiconductor device according to embodiment 2; Fig. Figure 4 schematically illustrates a top view of the semiconductor device according to a modification 1 of embodiment 2, when looking down at the lead electrode contained in the semiconductor device; Fig. Figure 5 schematically illustrates a cross-sectional view of the semiconductor device according to a modification 2 of embodiment 2; Fig. Figure 6 is a circuit diagram illustrating a structure of the semiconductor device according to a modification 3 of embodiment 2; Fig. Figure 7 is a circuit diagram illustrating a structure of the semiconductor device according to a modification 4 of embodiment 2; Fig. Figure 8 schematically illustrates a cross-sectional view of the semiconductor device according to a modification 5 of embodiment 2; Fig. Figure 9A illustrates a top view of an example of the lead electrode included in the semiconductor device according to a modification 6 of embodiment 2; Fig. Figure 9B illustrates a top view of another example of the lead electrode included in the semiconductor device according to modification 6 of embodiment 2; Fig. Figure 10 schematically illustrates a cross-sectional view of a semiconductor device according to embodiment 3; Fig. Figure 11 schematically illustrates a cross-sectional view of a semiconductor device according to embodiment 4; Fig. Figure 12 schematically illustrates a cross-sectional view of a semiconductor device according to embodiment 5; and Fig. Figure 13 is a block diagram illustrating a configuration of a power conversion system for which a power conversion device according to embodiment 6 is used. DESCRIPTION OF PREFERRED EXECUTION FORMS

[0013] The present invention is defined in the dependent claims. The sub-claims describe advantageous embodiments of the invention. Aspects of the present invention, as defined in the claims, are explained below with reference to the figures and embodiments. [Design 1][Structure of a semiconductor device]

[0014] In the following, embodiment 1 is described with reference to the drawings. Fig. Figure 1 schematically illustrates a cross-sectional view of a semiconductor device 50 according to embodiment 1. Fig. Figure 2 schematically illustrates a top view of the semiconductor device 50 according to embodiment 1, looking down at a lead electrode 9 contained in the semiconductor device 50.

[0015] As in Fig. As illustrated in Figure 1, the semiconductor device 50 comprises a cooling mechanism 1, a metal structure 2, an insulating layer 3, circuit structures 4, semiconductor elements 5, an insulating component 6, lead electrodes 8 and 9 and a sealing resin 10.

[0016] The cooling mechanism 1 consists mainly of Al or Cu, is a structure with a rib or fin structure inside and has a water cooling function.

[0017] The metal structure 2 is arranged on the upper surface of the cooling mechanism 1 via a thermal paste (not illustrated). The metal structure 2 consists primarily of copper. Made of a material with high thermal conductivity, the metal structure 2 can effectively dissipate the heat generated in the semiconductor elements 5 and increase the service life of the semiconductor device 50.

[0018] The insulating layer 3 is arranged on the upper surface of the metal structure 2. The insulating layer 3 consists primarily of Al₂O₃, Al₂O₃, or SiN. The circuit structures 4 are arranged on the upper surface of the insulating layer 3. Applying a material with a higher thermal conductivity than the insulating layer 3 can improve heat dissipation from the circuit structures 4 through the insulating layer 3 to the metal structure 2. This can inhibit an increase in the temperature of the semiconductor elements 5 and increase the lifetime of the semiconductor device 50.

[0019] The insulating layer 3 can consist primarily of a resin with a thermal conductivity higher than or equal to 10 W / m·K. An insulating layer 3 made of a deformation-resistant material with high thermal conductivity can prevent cracks that occur, for example, when the thermal cycle slightly deforms the components of the semiconductor device 50. This allows for high heat dissipation combined with high reliability. Furthermore, such a material is less expensive.

[0020] An internal connector 8a of the lead electrode 8, the semiconductor element 5, and the insulating component 6 are bonded to the upper surface of one of the circuit structures 4. The internal connector 8a of the lead electrode 8 is bonded to the upper surface of the circuit structure 4 by a bonding material 7. The semiconductor element 5 is bonded to the upper surface of the circuit structure 4 by a first bonding material 7a. The insulating component 6 is bonded to the upper surface of the circuit structure 4 by a second bonding material 7b. The lead electrode 9, which connects the semiconductor element 5 to the insulating component 6, is bonded to the upper surface of the semiconductor element 5 by a third bonding material 7c and to the upper surface of the insulating component 6 by a fourth bonding material 7d.

[0021] Thus, the second bonding material 7b and the fourth bonding material 7d are applied to the lower surface and the upper surface, respectively, of the insulating component 6. The thicknesses of the second bonding material 7b and the fourth bonding material 7d are adjustable. Adjusting the thicknesses of the second bonding material 7b and the fourth bonding material 7d to suitable thicknesses allows them to act as cushions for the insulating component 6. This can reduce the stress exerted on the insulating component 6.

[0022] The insulating component 6 is positioned between an external connector 9b and a section or sub-area of ​​an internal connector 9a of the lead electrode 9, to which the semiconductor element 5 is bonded. Furthermore, a sub-area of ​​the internal connector 9a of the lead electrode 9, to which the insulating component 6 is bonded, is pressed downwards. The other sub-areas of the lead electrode 9 are plate-shaped. The heat generated in the semiconductor element 5 is dissipated from the lower surface of the semiconductor element 5 to the circuit structure 4. Heat is also conducted from the upper surface of the semiconductor element 5 to the lead electrode 9 and from the lead electrode 9 through the insulating component 6 to the circuit structure 4. This prevents an increase in the temperature of the semiconductor element 5 and the lead electrode 9.

[0023] The insulating component 6 consists mainly of Si, Al₂O₃, Al₂O₃, or SiN with an oxidized film or resin having a thermal conductivity higher than that of the sealing resin 10. Using a material with high thermal conductivity as the insulating component 6 efficiently conducts the heat from the lead electrode 9 through the insulating component 6 to the cooling mechanism 1. This can inhibit an increase in the temperature of the semiconductor element 5 and the lead electrode 9. Furthermore, the lifetime of the semiconductor device 50 can be increased, and its temperature characteristics can be improved.

[0024] Since the first bonding material 7a, the second bonding material 7b, the third bonding material 7c, and the fourth bonding material 7d are made of the same material, the heating times required for bonding can be reduced. This prevents heat damage to the components of the semiconductor device 50. Specifically, the first bonding material 7a, the second bonding material 7b, the third bonding material 7c, and the fourth bonding material 7d are made of a solder metal or silver. These bonding materials, which have high thermal conductivity, can effectively dissipate heat from the upper and lower surfaces of the semiconductor element 5 and from the lead electrode 9 through the insulating component 6 to the cooling mechanism 1.This can inhibit an increase in the temperature of the semiconductor element 5 and the lead electrode 9, improve the longevity of the semiconductor device 50, and enhance the temperature characteristics of the semiconductor device 50. The bonding material 7 is also made of the same material as that of the first bonding material 7a, the second bonding material 7b, the third bonding material 7c, and the fourth bonding material 7d.

[0025] The lead electrodes 8 and 9 consist primarily of copper. Made of a material with high thermal conductivity, the lead electrodes 8 and 9 can effectively dissipate the heat generated in the semiconductor element 5. This stabilizes the quality of the semiconductor device 50.

[0026] The cross-sectional area of ​​the lead electrode 9 is dimensioned such that the exothermic temperature of the lead electrode 9, which is subject to a conductor resistance, is lower than the exothermic temperature of the semiconductor element 5 when the semiconductor device 50 is driven. This is described below. Assume that T1 denotes the exothermic temperature of the semiconductor element 5 and T2 denotes the exothermic temperature of the lead electrode 9. If the relationship T1 > T2 is satisfied, the heat generated in the semiconductor element 5 is dissipated through the lead electrode 9 and the insulating component 6 to the cooling mechanism 1. The relationship T1 > T2 requires a relationship R1 > R2, where R1 denotes a resistance value of the semiconductor element 5 and R2 denotes a resistance value of the lead electrode 9.Assuming that ρ denotes the resistivity of the lead electrode 9, L denotes the length of the lead electrode 9, and A denotes the cross-sectional area of ​​the lead electrode 9, then R2 is expressed by R2 = ρ × L / A. Thus, an increase in the cross-sectional area A of the lead electrode 9 satisfies the relationship R1 > R2, that is, T1 > T2.

[0027] As described above, increasing the cross-sectional area A of the lead electrode 9 conducts the heat generated in the semiconductor element 5 through the lead electrode 9 and the insulating component 6 to the cooling mechanism 1. Since this reduces the temperature of the semiconductor element 5, the maximum temperature of the semiconductor device 50 is also reduced. This increases the lifespan of the semiconductor device 50 and ensures stable operation.

[0028] The lead electrode 9 can have a non-constant width. Increasing the width of the current path more than that of the other sections in the lead electrode 9 can reduce the current density. This, in turn, can reduce the amount of heat generated in the resistance of the lead electrode 9. This can inhibit an increase in the temperature of the semiconductor device 50.

[0029] A reverse-conducting insulated-gate bipolar transistor (RC-IGBT) is used as the semiconductor element 5. This reduces the area of ​​the semiconductor element 5, thus miniaturizing the semiconductor device 50. Since the RC-IGBT is always in an energized state, its temperature tends to rise more than that of a semiconductor device containing an IGBT chip and a diode chip. However, the structure according to embodiment 1 allows heat to be dissipated from the upper surface of the semiconductor element 5 via the lead electrode 9. This enables the semiconductor device 50 to operate stably, preventing a temperature increase.

[0030] Furthermore, the semiconductor element 5 consists of SiC as the semiconductor material. The use of low-loss semiconductor elements 5 can reduce the heat generated within them. This can reduce the maximum temperature of the semiconductor device 50 and increase its lifespan. Since the amount of power consumed in the semiconductor device 50 can be reduced, energy can be saved.

[0031] The sealing resin 10 is an epoxy resin or gel and seals partial areas of the metal structure 2, with the exception of the lower surface, the insulating layer 3, the circuit structures 4, the internal connectors 8a and 9a of the supply electrodes 8 and 9, the semiconductor elements 5, and the insulating component 6. The external connectors 8b and 9b of the supply electrodes 8 and 9 protrude from the sealing resin 10.

[0032] Consider how in Fig. Figure 2 illustrates the semiconductor device 50, in which the two circuit structures 4 are arranged in parallel and a lead electrode 12 is arranged parallel to the lead electrode 8, with the lead electrode 12 and the lead electrode 8 being positioned on their respective circuit structures 4. Since the sealing resin 10 can reduce the insulation distances between the two circuit structures 4 and between the lead electrode 8 and the lead electrode 12, the semiconductor device 50 can be made smaller. Furthermore, the sealing resin 10 serves to protect the semiconductor elements 5. Thus, the sealing resin 10 can cushion the semiconductor elements against external shocks and increase the service life of the semiconductor device 50. [Advantages]

[0033] As described above, the semiconductor device 50 according to embodiment 1 comprises: the insulating layer 3; the circuit structure 4 on the upper surface of the insulating layer 3; the semiconductor element 5, which is bonded to the upper surface of the circuit structure 4 by the first bonding material 7a; the insulating component 6, which is bonded to the upper surface of the circuit structure 4 by the second bonding material 7b;and the lead electrode 9, which connects the semiconductor element 5 to the insulating component 6, wherein the upper surface of the semiconductor element 5 is bonded to the lower surface of the lead electrode 9 by the third bonding material 7c, the upper surface of the insulating component 6 is bonded to the lower surface of the lead electrode 9 by the fourth bonding material 7d, and the first bonding material 7a, the second bonding material 7b, the third bonding material 7c, and the fourth bonding material 7d are made of the same material.

[0034] Thus, adjusting the thickness of the second bonding material 7b for bonding the insulating component 6a to the upper surface of the circuit structure 4 and the thickness of the fourth bonding material 7d for bonding the upper surface of the insulating component 6 to the lower surface of the supply electrode 9 can reduce the voltage exerted on the insulating component 6.

[0035] Since the first bonding material 7a, the second bonding material 7b, the third bonding material 7c, and the fourth bonding material 7d consist of the same material, the heating times required for bonding can be reduced. This prevents heat damage to the components of the semiconductor device 50 and thus increases the reliability of the semiconductor device 50.

[0036] Furthermore, the lead electrode 9 includes the external connector 9b, which can be connected to an external device. The insulating component 6 is arranged between the external connector 9b and a portion of the lead electrode 9 to which the semiconductor element 5 is bonded. Thus, the heat generated in the semiconductor element 5 is dissipated to the circuit structure 4 via the insulating component 6. This prevents an increase in the temperature of the semiconductor element 5 and the lead electrode 9.

[0037] Furthermore, the semiconductor device 50 includes the sealing resin 10, which seals a portion of the lead electrode 9, the semiconductor element 5, and the insulating component 6. The sealing resin 10 is an epoxy resin or gel. Since the sealing resin 10 can reduce the insulation distance between the circuit structure 4 and the lead electrode 9 in the semiconductor device 50, the semiconductor device 50 can be made smaller. In addition, the sealing resin 10 serves to protect the semiconductor elements 5. Consequently, the sealing resin 10 can cushion the semiconductor elements 5 against external shocks and increase the service life of the semiconductor device 50.

[0038] The insulating component 6 contains Si, Al₂O₃, or SiN with an oxidized film or a resin with a higher thermal conductivity than that of the sealing resin 10. This material efficiently conducts the heat from the lead electrode 9 through the insulating component 6 to the cooling mechanism 1. Thus, an increase in the temperature of the semiconductor element 5 and the lead electrode 9 can be prevented. Furthermore, the lifetime of the semiconductor device 50 can be increased, and the temperature characteristics of the semiconductor device 50 can be improved.

[0039] Furthermore, the copper-containing lead electrode 9 can effectively dissipate the heat generated in the semiconductor element 5. This stabilizes the quality of the semiconductor device 50.

[0040] Since the first bonding material 7a contains a solder metal or silver, the second bonding material 7b, the third bonding material 7c, and the fourth bonding material 7d also contain a solder metal or silver. This enables effective heat dissipation from the upper and lower surfaces of the semiconductor element 5 and from the lead electrode 9 through the insulating component 6 to the cooling mechanism 1. Thus, an increase in the temperature of the semiconductor element 5 and the lead electrode 9 can be prevented. Furthermore, the lifetime of the semiconductor device 50 can be increased, and its temperature characteristics can be improved.

[0041] The cross-sectional area of ​​the lead electrode 9 is dimensioned such that its exothermic temperature, which is subject to conductor resistance, is lower than the exothermic temperature of the semiconductor element 5 when the semiconductor device 50 is driven. Thus, the heat from the semiconductor element 5 is conducted to the lead electrode 9. The temperature of the semiconductor element 5 is then reduced. Consequently, the maximum temperature of the semiconductor device 50 is reduced. This leads to an increase in the lifetime of the semiconductor device 50 and to its stable operation.

[0042] The insulating layer 3 contains Al₂O₃, Al₂O₃, or SiN. Using an insulating layer with high thermal conductivity than the insulating layer 3 can improve heat dissipation from the circuit structures 4 to the metal structure 2. This can inhibit an increase in the temperature of the semiconductor device 50 and increase its lifespan.

[0043] The insulating layer 3 contains a resin with a thermal conductivity greater than or equal to 10 W / m·K. Using an insulating layer 3 made of a deformation-resistant resin with high thermal conductivity can prevent cracks that may arise, for example, when the thermal cycle causes slight deformation of the components of the semiconductor device 50. This can reconcile high heat dissipation with high reliability in the semiconductor device 50.

[0044] The semiconductor device 50 further comprises the metal structure 2, which is arranged on a lower surface of the insulating layer 3, wherein the metal structure 2 contains copper. The metal structure 2, which consists of a material with high thermal conductivity, can effectively dissipate the heat generated in the semiconductor elements 5 and increase the lifetime of the semiconductor device 50.

[0045] Since the lead electrode 9 has a non-constant width, increasing the width of the current path more than that of the other sub-areas in the lead electrode 9 can reduce the current density. Because this can reduce the amount of heat generated in the conductor resistance of the lead electrode 9, an increase in the temperature of the semiconductor device 50 can be inhibited.

[0046] Since the semiconductor element 5 is an RC-IGBT, its area can be reduced. Thus, the semiconductor device 50 can be made smaller. Because the RC-IGBT is always in an excited state, its temperature tends to rise more than that of a semiconductor device containing an IGBT chip and a diode chip. However, the heat can be dissipated from the upper surface of the semiconductor element 5 via the lead electrode 9. Consequently, the semiconductor device 50 can operate stably, inhibiting any increase in temperature.

[0047] Since the semiconductor element 5 is made of SiC as the semiconductor material, the heat generated in the semiconductor element 5 can be reduced. This allows the maximum temperature of the semiconductor device 50 to be reduced and its service life to be increased. Since the amount of power consumed in the semiconductor device 50 can be reduced, energy can be saved. [Version 2]

[0048] Next, a semiconductor device 50A according to embodiment 2 is described. Fig. Figure 3 schematically illustrates a cross-sectional view of the semiconductor device 50A according to embodiment 2. In embodiment 2, the same reference numerals are assigned to the same component elements described in embodiment 1, and their description is omitted.

[0049] As in Fig. As illustrated in Figure 3, the shape of the supply electrode 9 according to embodiment 2 differs from that according to embodiment 1. Specifically, the part of the supply electrode 9 to which the insulating component 6 is bonded is pressed downwards according to embodiment 1, whereas the entire supply electrode 9 according to embodiment 2 is plate-shaped.

[0050] As described above, the lead electrode 9 in the semiconductor device 50A according to embodiment 2 is plate-shaped. Although a processing error in a bending process according to embodiment 1 can cause stress to be exerted on the insulating component 6, the use of the plate-shaped lead electrode 9 as in embodiment 2 eliminates the processing error. Consequently, stress on the insulating component 6 can be prevented. [Modifications of embodiment 2]

[0051] Next, modifications of embodiment 2 will be described. Fig. Figure 4 schematically illustrates a top view of the semiconductor device 50A according to a modification 1 of embodiment 2, when looking down at the lead electrode 9 contained in the semiconductor device 50A. Fig. Figure 5 schematically illustrates a cross-sectional view of the semiconductor device 50A according to a modification 2 of embodiment 2. Fig. Figure 6 is a circuit diagram illustrating a structure of the semiconductor device 50A according to a modification 3 of embodiment 2. Fig. Figure 7 is a circuit diagram illustrating a structure of the semiconductor device 50A according to a modification 4 of embodiment 2. Fig. Figure 8 schematically illustrates a cross-sectional view of the semiconductor device 50A according to a modification 5 of embodiment 2. Fig. Figure 9A illustrates a top view of an example of the lead electrode 9 included in the semiconductor device 50A according to a modification 6 of embodiment 2. Fig. Figure 9B illustrates a top view of another example of the lead electrode 9 included in the semiconductor device 50A according to modification 6 of embodiment 2.

[0052] As in Fig. As illustrated in Figure 4, a through-hole 9c can be formed in a first bonding sub-region of the lead electrode 9, to which the semiconductor element 5 is bonded, and a through-hole 9d can be formed in a second bonding sub-region of the lead electrode 9, to which the insulating component 6 is bonded. The through-hole 9c and the through-hole 9d have shorter diameters than the first and second bonding sub-regions, respectively. Since the third bonding material 7c and the fourth bonding material 7d are applied through the through-hole 9c and the through-hole 9d, respectively, the through-holes 9c and 9d can prevent the spread of the third bonding material 7c and the fourth bonding material 7d beyond the bonding sub-regions and inhibit the conduction of electricity to sub-regions other than those being bonded. This can improve the reliability of the semiconductor device 50A.

[0053] As in Fig. As illustrated in Figure 5, the semiconductor device 50A can have a large number of semiconductor elements 5 (for example, two semiconductor elements 5). Since this can increase the voltage and current that can be applied to the semiconductor device 50, the semiconductor device 50A can generate a high output power.

[0054] As in Fig. 6 and Fig. As illustrated in Figure 7, the multitude of semiconductor elements 5 can be arranged in parallel. The semiconductor element 5 comprises a set of an IGBT and a freewheeling diode (FWD). For example, considering the heat generated between a collector 1 and an emitter 1, a drive of an IGBT 1, an FWD 1, an IGBT 2, and an FWD 2, as shown in Figure 7, can be used. Fig. Figure 7 illustrates how the heat-generating sub-areas are distributed more evenly than by controlling only the IGBT 1 and the FWD 1, as shown in Figure 7. Fig. Figure 6 illustrates this. Consequently, the maximum temperature of the semiconductor device 50 can be reduced, and the semiconductor device 50 can operate stably.

[0055] As in Fig. As illustrated in Figure 8, the semiconductor device 50A can have a plurality of insulating components 6 (for example, two insulating components 6). Since the heat generated in the semiconductor elements 5 is dissipated to the cooling mechanism 1 via the lead electrode 9 and the insulating components 6, the plurality of insulating components 6 can improve heat dissipation and increase the service life of the semiconductor device 50A.

[0056] As in Fig. 9A and Fig. As illustrated in Figure 9B, roughened sub-areas 11 can be formed around the circumferences of the through holes 9c and 9d in the supply electrode 9, the surfaces of which are rougher than other surfaces than the circumferences of the through holes 9c and 9d in the supply electrode 9.

[0057] Specifically, the ring-shaped roughened sections 11 can be arranged around the circumferences of the through holes 9c and 9d as shown in Fig. Figure 9 illustrates the formation on the lower surface of the supply electrode 9. Alternatively, the rectangular roughened sections 11, which define the circumferences of the through holes 9c and 9d, can be formed as shown in Fig. 9B illustrates including, formed on the lower surface of the lead electrode 9.

[0058] If the fourth bonding material 7d on the upper surface of the insulating component 6 runs excessively, contact between the fourth bonding material 7d and the second bonding material 7b on the lower surface of the insulating component 6 causes the insulating component 6 to lose its insulating properties. The roughened areas 11 formed around the circumferences of the through holes 9c and 9d on the lower surface of the lead electrode 9 can prevent the fourth bonding material 7d from running excessively and improve the insulating properties of the insulating component 6.

[0059] The details of the modifications of embodiment 2 can be combined with other embodiments. [Version 3]

[0060] Next, a semiconductor device 50B according to embodiment 3 is described. Fig. Figure 10 schematically illustrates a cross-sectional view of the semiconductor device 50B according to embodiment 3. The same reference numerals are assigned to the same component elements described in embodiments 1 and 2, and their description is omitted.

[0061] As in Fig. As illustrated in Figure 10, the semiconductor device 50B according to embodiment 3 has a plurality of structures (for example, two structures), each comprising the metal structure 2, the insulating layer 3, and the circuit structure 4. The semiconductor element 5 and the insulating component 6 are bonded to the respective upper surfaces of the circuit structures 4. The structure according to embodiment 3 can be combined with those of other embodiments.

[0062] As described above, the semiconductor device 50B according to embodiment 3 has a plurality of circuit structures 4, wherein the semiconductor element 5 and the insulating component 6 are bonded to respective upper surfaces of two of the plurality of circuit structures 4. This structure eliminates interference of the heat conducted to each circuit structure 4. Consequently, the heat dissipation of the semiconductor device 50B can be improved. [Version 4]

[0063] Next, a semiconductor device 50C according to embodiment 4 is described. Fig. Figure 11 schematically illustrates a cross-sectional view of the semiconductor device 50C according to embodiment 4. In embodiment 4, the same reference numerals are assigned to the same component elements described in embodiments 1 to 3, and their description is omitted.

[0064] As in Fig. As illustrated in Figure 11, the insulating component 6, according to embodiment 4, is not bonded to the upper surface of the circuit structure 4, but rather to the upper surface of the cooling mechanism 1 by means of the second bonding material 7b. Furthermore, a portion of the internal connector 9a of the supply electrode 9, to which the insulating component 6 is bonded, is pressed downwards. The other portions of the supply electrode 9 are plate-shaped.

[0065] As described above, the semiconductor device 50C according to embodiment 4 comprises: the cooling mechanism 1; the insulating layer 3 arranged above the cooling mechanism 1; the circuit structure 4 arranged on an upper surface of the insulating layer 3; the semiconductor element 5 bonded to an upper surface of the circuit structure 4 by the first bonding material 7a; the insulating component 6 bonded to an upper surface of the cooling mechanism 1 by the second bonding material 7b;and the lead electrode 9, which connects the semiconductor element 5 to the insulating component 6, wherein an upper surface of the semiconductor element 5 is bonded to a lower surface of the lead electrode 9 by the third bonding material 7c, an upper surface of the insulating component 6 is bonded to the lower surface of the lead electrode 9 by the fourth bonding material 7d, and the first bonding material 7a, the second bonding material 7b, the third bonding material 7c, and the fourth bonding material 7d are made of the same material.

[0066] Since the heat generated in the semiconductor element 5 can be dissipated directly to the cooling mechanism 1 without passing through the insulating layer 3, an increase in the temperature of the semiconductor device 50C can be further inhibited. [Version 5]

[0067] Next, a semiconductor device 50D according to embodiment 5 is described. Fig. Figure 12 schematically illustrates a cross-sectional view of the semiconductor device 50D according to embodiment 5. In embodiment 5, the same reference numerals are assigned to the same component elements described in embodiments 1 to 4, and their description is omitted.

[0068] As in Fig. As illustrated in Figure 12, the semiconductor device 50D according to embodiment 5, in addition to the structure according to embodiment 2, also has a circuit structure 24, an insulating layer 23, a metal structure 22 and a cooling mechanism 21 above the supply electrode 9.

[0069] A portion of the upper surface of the lead electrode 9, to which the semiconductor element 5 is bonded, and a portion of the upper surface of the lead electrode 9, to which the insulating component 6 is bonded, are bonded to a lower surface of the circuit structure 24 by a fifth bonding material 7e and a sixth bonding material 7f, respectively. The fifth bonding material 7e and the sixth bonding material 7f consist of the same material as that of the first bonding material 7a, the second bonding material 7b, the third bonding material 7c, and the fourth bonding material 7d.

[0070] As described above, the semiconductor device 50D according to embodiment 5 further comprises: the insulating layer 23, which is distinct from the insulating layer 3; and the circuit structure 24, which is distinct from the circuit structure 4, wherein the circuit structure 24 is arranged on a lower surface of the insulating layer 23, wherein the circuit structure 24 is arranged above the lead electrode 9, a portion of the upper surface of the lead electrode 9, to which the semiconductor element 5 is bonded, and a portion of the upper surface of the lead electrode 9, to which the insulating component 6 is bonded, are bonded to the circuit structure 24 by the fifth bonding material 7e and the sixth bonding material 7f, respectively, and the first bonding material, the second bonding material, the third bonding material, the fourth bonding material, the fifth bonding material, and the sixth bonding material consist of the same material.

[0071] Thus, the heat generated in the semiconductor element 5 is also spread or distributed above the lead electrode 9 by the lead electrode 9. This can further improve the heat dissipation of the semiconductor device 50D. Since an increase in the temperature of the semiconductor device 50D is further inhibited, the service life of the semiconductor device 50D can be improved. [Version 6]

[0072] One embodiment 6 describes a power conversion device for which the semiconductor devices 50 to 50D according to embodiments 1 to 5 are used. Although the application of the semiconductor devices 50 to 50D according to embodiments 1 to 5 is not limited to specific power conversion devices, embodiment 6 describes the application of the semiconductor devices 50 to 50D according to embodiments 1 to 5 to a three-phase inverter.

[0073] Fig. Figure 13 is a block diagram illustrating a configuration of a power conversion system for which a power conversion device 200 according to embodiment 6 is used.

[0074] The in Fig. Figure 13 illustrates a power conversion system comprising a power supply 100, a power conversion device 200, and a load 300. The power supply 100, which is a DC power supply, provides DC power to the power conversion device 200. The power supply 100 can include various components such as a DC system, a solar battery, a rechargeable battery, a rectifying circuit connected to an AC system, or an AC / DC converter. The power supply 100 can include a DC / DC converter that converts the DC power supplied by a DC system into a predetermined power output.

[0075] The power conversion device 200, which is a three-phase inverter connected between the power supply 100 and the load 300, converts the DC power supplied by the power supply 100 into AC power in order to supply the load 300 with AC power. As shown in Fig. As illustrated in Figure 13, the power conversion device 200 includes a main conversion circuit 201 that converts the DC power into AC power, a drive circuit 202 that provides a drive signal to control each switching element in the main conversion circuit 201, and a control circuit 203 that provides a control signal to the drive circuit 202 to control the drive circuit 202.

[0076] The Last 300 is a three-phase electric motor driven by AC power supplied by the power conversion device 200. The Last 300 is not limited to a specific application but is a versatile electric motor suitable for mounting on various types of electrical equipment. For example, the Last 300 can be used as an electric motor in hybrid vehicles, electric vehicles, rail vehicles, elevators, or air conditioning systems.

[0077] The power conversion device 200 is described in detail below. The main conversion circuit 201 contains (not illustrated) switching elements and freewheeling diodes. A switching operation of the switching element causes the DC power supplied by the power supply 100 to be converted into AC power. The AC power is then supplied to the load 300. The specific circuit configuration of the main conversion circuit 201 varies. The main conversion circuit 201 according to embodiment 6 is a three-phase, two-level full-bridge circuit and comprises six switching elements and six freewheeling diodes connected antiparallel to the respective switching elements. Any one of the semiconductor devices 50 to 50D according to embodiments 1 to 5 is used for each of the switching elements of the main conversion circuit 201.The six switching elements form three pairs of upper and lower arms, with the two switching elements in each pair connected in series. These three pairs of upper and lower arms constitute the respective phases (U-phase, V-phase, and W-phase) of the full bridge circuit. The output terminals of each pair of upper and lower arms, i.e., the three output terminals, of the main conversion circuit 201 are connected to the load 300.

[0078] The control circuit 202 generates control signals for controlling the switching elements of the main conversion circuit 201 and provides these control signals to the control electrodes of the switching elements of the main conversion circuit 201. Specifically, the control circuit 202 outputs to a control electrode of each of the switching elements, according to the control signal from the control circuit 203, which will be described later, the control signal to switch the switching element to an ON state and the control signal to switch the switching element to an OFF state. The control signal is a voltage signal (ON signal) that is equal to or higher than a threshold voltage of the switching element when the switching element is held in the ON state. The control signal is a voltage signal (OFF signal) that is equal to or lower than the threshold voltage of the switching element when the switching element is held in the OFF state.

[0079] The control circuit 203 controls the switching elements of the main conversion circuit 201 to provide the desired power to the load 300. Specifically, the control circuit 203 calculates a time (ON time) at which each of the switching elements of the main conversion circuit 201 must enter the ON state, based on the power that must be supplied to the load 300. For example, the main conversion circuit 201 can be controlled by using PWM control to modulate the ON time of the switching elements according to the voltage that must be delivered. The control circuit 203 then sends a control instruction (a control signal) to the drive circuit 202, so that the drive circuit 202 sends the ON signal to the switching element that must enter the ON state and the OFF signal to the switching element that must enter the OFF state.According to this control signal, the control circuit 202 outputs the ON signal or the OFF signal as the control signal to the control electrode of each of the switching elements.

[0080] Since the semiconductor devices 50 to 50D according to embodiments 1 to 5 are used for the switching elements of the main conversion circuit 201 in the power conversion device 200 according to embodiment 6, the load or voltage exerted on the insulating layer 3 arranged under the insulating component 6 can be reduced, and the reliability of the semiconductor devices 50 to 50D can be improved. This can improve the reliability of the power conversion device 200.

[0081] Although embodiment 6 describes an example in which the semiconductor devices 50 to 50D according to embodiments 1 to 5 are used for a two-level three-phase inverter, the semiconductor devices 50 to 50D according to embodiments 1 to 5 are not limited to the three-phase inverter but can be used for various power converters. Although embodiment 6 describes the two-level power conversion device, the power conversion device can have three or more levels. The semiconductor devices 50 to 50D according to embodiments 1 to 5 can be used for a single-phase inverter when power is supplied to a single-phase load. For example, when power is supplied to a DC load, the semiconductor devices 50 to 50D according to embodiments 1 to 5 can also be used for a DC / DC converter or an AC / DC converter.

[0082] The load of the power conversion device, for which the semiconductor devices 50 to 50D according to embodiments 1 to 5 are used, is not limited to the electric motor as described above. The power conversion device can also be used as a power supply device for an electrical discharge machine, a laser beam machine, a cooking device with induction heating, or a contactless power supply system, and can furthermore be used as a power conditioner for, for example, a solar energy system or an electricity storage system.

[0083] The above embodiments can be combined.

Claims

[1] Semiconductor device comprising: an insulating layer (3); a circuit structure (4) arranged on an upper surface of the insulating layer (3); a semiconductor element (5) which is bonded to an upper surface of the circuit structure (4) by a first bonding material (7a); an insulating component (6) which is bonded to the upper surface of the circuit structure (4) by a second bonding material (7b); and a lead electrode (9) that connects the semiconductor element (5) to the insulating component (6), wherein an upper surface of the semiconductor element (5) is bonded to a lower surface of the lead electrode (9) by a third bonding material (7c), an upper surface of the insulating component (6) is bonded to the lower surface of the lead electrode (9) by a fourth bonding material (7d) and the first bonding material (7a), the second bonding material (7b), the third bonding material (7c) and the fourth bonding material (7d) consist of the same material, characterized by , that an insulating layer (23) that is different from the insulating layer (3); and a circuit structure (24) that is different from the circuit structure (4), wherein the different circuit structure (24) is arranged on a lower surface of the different insulating layer (23), wherein the various circuit structure (24) is arranged above the supply electrode (9), a sub-area of ​​the upper surface of the lead electrode (9), to which the semiconductor element (5) is bonded, and a sub-area of ​​the upper surface of the lead electrode (9), to which the insulating component (6) is bonded, are bonded to the various circuit structures (24) respectively by a fifth bonding material (7e) and a sixth bonding material (7f). the first bonding material (7a), the second bonding material (7b), the third bonding material (7c), the fourth bonding material (7d), the fifth bonding material (7e) and the sixth bonding material (7f) are made of the same material. [2] Semiconductor device according to claim 1, wherein the lead electrode (9) comprises an external connector (9b) which can be connected to an external device, and the insulating component (6) is arranged between the external connector (9b) and a part of the lead electrode (9) to which the semiconductor element (5) is bonded. [3] Semiconductor device according to claim 1 or claim 2, further comprising: a sealing resin (10) that seals part of the lead electrode (9), the semiconductor element (5) and the insulating component (6), wherein the sealing resin (10) contains an epoxy resin or gel. [4] Semiconductor device according to claim 3, wherein the insulating component (6) comprises Si, AIN, Al2O3 or SiN with an oxidized film or a resin having a higher thermal conductivity than the thermal conductivity of the sealing resin (10). [5] Semiconductor device according to any one of claims 1 to 4, wherein the lead electrode (9) contains copper. [6] Semiconductor device according to any one of claims 1 to 5, wherein the first bonding material (7a) contains a solder metal or silver. [7] Semiconductor device according to any one of claims 1 to 6, wherein a cross-sectional area of ​​the lead electrode (9) is dimensioned such that an exothermic temperature of the lead electrode (9) which is subject to a conductor resistance is lower than an exothermic temperature of the semiconductor element (5) when the semiconductor device is driven. [8] Semiconductor device according to any one of claims 1 to 7, wherein the insulating layer (3) contains AIN, Al2O3 or SiN. [9] Semiconductor device according to any one of claims 1 to 8, wherein the insulating layer (3) contains a resin having a thermal conductivity higher than or equal to 10 W / m·K. [10] Semiconductor device according to any one of claims 1 to 9, further comprising a metal structure arranged on a lower surface of the insulating layer (3), the metal structure contains copper. [11] Semiconductor device according to claim 1, wherein the lead electrode (9) is plate-shaped. [12] Semiconductor device according to any one of claims 1 to 11, further comprising a first through-hole (9c) formed in a first bonding sub-area of ​​the lead electrode (9) to which the semiconductor element (5) is bonded, and a second through-hole (9d) formed in a second bonding sub-area of ​​the lead electrode (9) to which the insulating component (6) is bonded, wherein the first through-hole (9c) and the second through-hole (9d) have smaller diameters than the first bonding sub-area and the second bonding sub-area, respectively. [13] Semiconductor device according to one of claims 1 to 12, comprising a plurality of semiconductor elements (5) which includes the semiconductor element (5). [14] Semiconductor device according to claim 13, wherein the plurality of semiconductor elements (5) are arranged in parallel. [15] Semiconductor device according to any one of claims 1 to 14, comprising a plurality of insulating components (6) which includes the insulating component (6). [16] Semiconductor device according to claim 12, further comprising roughened sub-areas (11) formed around the perimeters of the first through-hole (9c) and the second through-hole (9d) in the feed electrode (9), wherein the roughened sub-areas (11) have surfaces that are rougher than surfaces other than the perimeters of the first through-hole (9c) and the second through-hole (9d) in the feed electrode (9). [17] Semiconductor device according to any one of claims 1 to 16, comprising a variety of circuit structures (4), the circuit structure (4) exhibits, wherein the semiconductor element (5) and the insulating component (6) are bonded to respective upper surfaces of two of the plurality of circuit structures (4). [18] Semiconductor device according to any one of claims 1 to 17, wherein the lead electrode (9) has a non-constant width. [19] Semiconductor device according to any one of claims 1 to 18, wherein the semiconductor element (5) is a backward conducting bipolar transistor with an insulated gate. [20] Semiconductor device according to any one of claims 1 to 19, wherein the semiconductor element (5) contains SiC as the semiconductor material. [21] Power conversion device (200), comprising: a main conversion circuit (201) comprising the semiconductor device according to any one of claims 1 to 20 and converting an input power to deliver a resultant power; and a control circuit (203) which sends a control signal to the main conversion circuit (201) to control the main conversion circuit (201).

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