Semiconductor device, power conversion device, and mobile body

Abstract

The present application is made to solve such a problem, and aims to provide a semiconductor device capable of reducing cost. The semiconductor device according to the present application has a base plate, an insulating substrate provided on the base plate, a semiconductor chip provided on the insulating substrate, a first resin case and a second resin case installed on the base plate in a manner of housing the insulating substrate and the semiconductor chip inside, and the both are fitted to each other, and a sealing material which seals the insulating substrate and the semiconductor chip, and the first resin case and the second resin case are made of resin materials different in relative tracking index.

Description

TECHNICAL FIELD

[0001] The present application relates to a semiconductor device, a power conversion device to which the semiconductor device is applied, and a mobile body to which the power conversion device is applied. BACKGROUND

[0002] In recent years, in a power semiconductor device, along with the continuous development of the practical use of a wide bandgap semiconductor such as SiC (silicon carbide), the requirement for high heat resistance is continuously increasing. On the other hand, in the case of a power semiconductor device used in a severe environment, a material having a high comparative tracking index (CTI: Comparative Tracking Index) is required for a portion where insulation is ensured at the surface of the power semiconductor device based on the required specifications of, for example, JIS C 60664-1

[0003] (IEC60664-1) and the like. Therefore, in the case of a resin material used for a frame housing constituting a power semiconductor device, in addition to having mechanical properties such as mechanical strength for protecting the inside of the power semiconductor device, it becomes important to take into account both high heat resistance and a high comparative tracking index.

[0004] In the past, a power semiconductor constituted by a molded product of a PPS (polyphenylene sulfide) resin having high heat resistance and high mechanical strength, and excellent electric tracking resistance characteristics has been proposed (for example, refer to Patent Document 1).

[0005] In the past, a power semiconductor constituted by a molded product of a PPS (polyphenylene sulfide) resin having high heat resistance and high mechanical strength, and excellent electric tracking resistance characteristics has been proposed (for example, refer to Patent Document 1).

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-147943

[0007] Generally, in order to improve the heat resistance of a resin material, it is necessary to increase the glass transition temperature (Tg) of the resin material, but if the glass transition temperature is increased, the electric tracking resistance characteristics are reduced contrary thereto. That is, the glass transition temperature and the electric tracking resistance characteristics have a trade-off relationship. For example, if the glass transition temperature is increased by increasing the number of crosslinking points by the crosslinking units of the aromatic series, the number of aromatic rings increases and carbonization is easy, and the electric tracking resistance characteristics are reduced.

[0008] In addition, it has been studied to improve the electric tracking resistance characteristics by adding magnesium hydroxide, other polymers, and additives to the resin. However, it is also known that there are disadvantages such as the need for a high magnesium hydroxide content in order to obtain excellent electric tracking resistance characteristics, and if so, the mechanical strength and other properties of the resin composition are significantly reduced.

[0009] According to these reasons, a resin material that does not impair the mechanical properties of the resin itself and that has both high heat resistance and a high comparative tracking index is difficult to develop technically, the corresponding material is expensive, and options are very limited. Therefore, selection of such a limited resin material (a resin material for a frame housing) based on market requirements becomes a cause of an increase in the cost of a semiconductor device. SUMMARY

[0010] The present application has been made in view of the above problems, and has an object to provide a semiconductor device capable of reducing cost.

[0011] To solve the above problems, the semiconductor device according to the present application has a base plate, an insulating substrate provided on the base plate, a semiconductor chip provided on the insulating substrate, a first resin housing and a second resin housing installed on the base plate in a manner of housing the insulating substrate and the semiconductor chip inside, the first resin housing and the second resin housing being fitted to each other, and a sealing material sealing the insulating substrate and the semiconductor chip, the first resin housing and the second resin housing being composed of resin materials having different comparative tracking indices.

[0012] EFFECT OF THE INVENTION

[0013] According to the present application, the first resin housing and the second resin housing of the semiconductor device are composed of resin materials having different comparative tracking indices, and thus cost reduction is possible.

[0014] The object, features, schemes, and advantages of the present application will become more apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a sectional view showing one example of a structure of the semiconductor device according to Embodiment 1.

[0016] Figure 2 is a flowchart showing one example of a manufacturing process of the semiconductor device according to Embodiment 1.

[0017] Figure 3 is a sectional view showing one example of a structure of the semiconductor device according to Embodiment 1.

[0018] Figure 4 is a sectional view showing one example of a structure of the semiconductor device according to Embodiment 1.

[0019] Figure 5 is a sectional view showing one example of a structure of the semiconductor device according to Embodiment 2.

[0020] Figure 6is a cross-sectional view showing one example of a structure of a semiconductor device to which Embodiment 3 is applied.

[0021] Figure 7 is a cross-sectional view showing one example of a structure of a semiconductor device to which Embodiment 4 is applied.

[0022] Figure 8 is a cross-sectional view showing one example of a structure of a semiconductor device to which Embodiment 5 is applied.

[0023] Figure 9 is a diagram showing one example of a structure of a power conversion device to which the semiconductor device according to Embodiments 1 to 5 is applied.

[0024] Figure 10 is a diagram showing one example of application of the power conversion device according to Embodiment 6 to a moving object. DETAILED DESCRIPTION

[0025] <Embodiment 1>

[0026] <Structure>

[0027] Figure 1 is a cross-sectional view showing one example of a structure of a semiconductor device to which Embodiment 1 is applied.

[0028] As shown in Figure 1 , an insulating substrate 3 is provided on a base plate 1. The base plate 1 is composed of a metal having a high thermal conductivity such as copper (Cu), aluminum (Al), an aluminum alloy, AlSiC, or MgSiC.

[0029] The insulating substrate 3 has a ceramic substrate 4, an upper surface electrode pattern 5 formed on an upper surface (a surface on the upper side of the paper) of the ceramic substrate 4, and a lower surface electrode pattern 6 formed on a lower surface (a surface on the lower side of the paper) of the ceramic substrate 4. The ceramic substrate 4 is composed of, for example, aluminum nitride, silicon nitride, or aluminum oxide. The upper surface electrode pattern 5 and the lower surface electrode pattern 6 are composed of, for example, copper or aluminum.

[0030] The base plate 1 and the lower surface electrode pattern 6 of the insulating substrate 3 are joined by a joining material 2. The joining material 2 is composed of, for example, solder, brazing material, sintered silver, or liquid phase diffusion material.

[0031] A semiconductor chip 8 and electrode terminals 10, 11 are provided on the upper surface electrode pattern 5 of the insulating substrate 3. The semiconductor chip 8 is electrically connected to the upper surface electrode pattern 5 via a bonding material 7. The semiconductor chip 8 is constituted of, for example, an IGBT (Insulated Gate Bipolar Transistor), a diode, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), or an RC-IGBT (Reverse Conducting IGBT). The bonding material 7 is constituted of, for example, solder, brazing material, sintered silver, or liquid phase diffusion material.

[0032] The electrode terminals 10, 11 are electrically connected to the upper surface electrode pattern 5. The electrode terminals 10, 11 are constituted of, for example, copper or aluminum.

[0033] The semiconductor chip 8 is electrically connected to the upper surface electrode pattern 5 via a metal wire 9. The metal wire 9 is constituted of, for example, aluminum, aluminum alloy, copper, or copper alloy.

[0034] The first resin case 12 and the second resin case 13 are fitted to each other in a manner of housing the insulating substrate 3 and the semiconductor chip 8 inside. Specifically, the second resin case 13 is provided at an end portion of the base plate 1 in a manner of constituting a part of a side wall of the semiconductor device. The first resin case 12 is provided so as to cover at least a side surface and an upper surface of the second resin case 13, and covers the entire inside of the semiconductor device. The electrode terminals 10, 11 are fixed to the first resin case 12, and end portions of the electrode terminals 10, 11 are exposed to the outside from the first resin case 12.

[0035] The first resin case 12 and the second resin case 13 are constituted of resin materials different from each other, for example, PPS (Polyphenylenesulfide), PPA (Polyphthalamide), LCP (Liquid Crystal Polymer), PES (Polyethersulfone), PA (Polyamide), PET (Polyethylene terephthalate), or PBT (Polybutylene terephthalate).

[0036] The relative tracking index of the first resin case 12 is higher than that of the second resin case 13. The relative tracking index (CTI) of the first resin case 12 and the second resin case 13 is greater than or equal to 100, and can be preferably 400 ≤ CTI < 600, and can be more preferably 600 ≤ CTI.

[0037] The glass transition temperature (Tg) of the first resin case 12 and the second resin case 13 is greater than or equal to 100°C, and can be preferably 150°C ≤ Tg, and more preferably 175°C ≤ Tg.

[0038] The surface distance and the space distance required for insulating the surface of the semiconductor device are sufficient with only the first resin case 12. The first resin case 12 and the second resin case 13 can be adhered by an adhesive, can be engaged by a snap fit, or can be formed by two-color molding.

[0039] The encapsulation material 14 encapsulates the semiconductor chip 8, the insulating substrate 3, and the metal wire 9 inside the semiconductor device surrounded by the first resin case 12 and the second resin case 13, and the base plate 1. The encapsulation material 14 is composed of an insulating material such as silicone gel or epoxy resin.

[0040] <Manufacturing Method>

[0041] Figure 2 This is a flowchart showing one example of the manufacturing process of the semiconductor device according to Embodiment 1.

[0042] In step S1, the insulating substrate 3 is joined to the base plate 1 by the joining material 2. Then, the semiconductor chip 8 is joined to the insulating substrate 3 by the joining material 7.

[0043] In step S2, the semiconductor chip 8 and the upper surface electrode pattern 5 of the insulating substrate 3 are wire-bonded by the metal wire 9.

[0044] In step S3, the second resin case 13 is mounted to the end portion of the base plate 1.

[0045] In step S4, the electrode terminals 10 and 11 are joined to the upper surface electrode pattern 5 of the insulating substrate 3.

[0046] In step S5, the first resin case 12 is fitted to the second resin case 13.

[0047] In step S6, the encapsulation material 14 is filled inside the semiconductor device surrounded by the first resin case 12 and the second resin case 13, and the base plate 1, in a manner to encapsulate the semiconductor chip 8, the insulating substrate 3, and the metal wire 9.

[0048] <Effects>

[0049] For example, for semiconductor devices used in severe environments such as solar power generation, wind power generation, and electric railway applications, at portions of the surface of the semiconductor device where insulation needs to be ensured, based on the specifications required by, for example, JIS C 60664-1 (IEC 60664-1), the minimum creepage distance and the minimum spacing distance that should be observed, which are determined by the relative tracking index of the material, the effective value of the voltage used, and the degree of contamination of the use environment, need to be satisfied.

[0050] In Embodiment 1, by using a resin material that takes into account both a high relative tracking index and a high heat resistance at a minimum portion required to ensure the creepage distance and the spacing distance (the first resin case 12), the material for the second resin case 13 can be selected independently of the value of the relative tracking index, and thus a cheap resin material can be selected. As a result, the material cost of the semiconductor device can be reduced.

[0051] By providing a structure in which the first resin case 12 and the second resin case 13 are engaged by a snap fit, the first resin case 12 and the second resin case 13 do not need to be adhered with an adhesive or the like. As a result, the productivity of the semiconductor device and the case can be improved.

[0052] By forming the first resin case 12 and the second resin case 13 by two-color molding, the assembly process of the first resin case 12 and the second resin case 13 is not required. As a result, the productivity of the semiconductor device and the case can be improved, and the material cost can be further reduced.

[0053] The second resin case 13 can select a material independently of the value of the relative tracking index, and thus a material that can further improve the heat resistance, the adhesion to other materials, the mechanical strength, and the like can be selected. As a result, the degree of freedom of the case design and the reliability of the semiconductor device can be further improved.

[0054] By making the second resin case 13 a general-purpose component, and changing only the structure of the first resin case 12, even in cases where the required insulation withstand voltage is different, a flexible response can be made. For example, as shown in Figure 3 , a recess and a protrusion can be provided on the side surface of the first resin case 12 to increase the creepage distance. In this way, by reducing the design man-hours of the semiconductor device and standardizing the semiconductor device, the cost of the semiconductor device can be reduced.

[0055] Further, the shapes of the first resin case 12 and the second resin case 13 are not limited to the shapes shown in Figure 1 , 3 . For example, as shown in Figure 1 , 3The shape shown is such that the first resin housing 12 covers the second resin housing 13, but it can also be like... Figure 4 The diagram shows a shape in which the first resin shell 12 and the second resin shell 13 are divided into upper and lower layers and interlocked with each other, but other shapes are also possible.

[0056] <Implementation Method 2>

[0057] <Structure>

[0058] Figure 5 This is a cross-sectional view showing an example of the structure of the semiconductor device according to Embodiment 2. For example... Figure 5 As shown, the semiconductor device according to Embodiment 2 is characterized in that the first resin housing 12 and the second resin housing 13 are fitted together with a concave-convex structure. Other structures are the same as those of the semiconductor device described in Embodiment 1, and therefore detailed descriptions are omitted here.

[0059] The first resin housing 12 is concave, and the second resin housing 13 is convex, with the first resin housing 12 fitting over the second resin housing 13. Alternatively, the first resin housing 12 may be convex, and the second resin housing 13 may be concave.

[0060] The encapsulation material 14 is filled up to the height of the mating portion of the first resin housing 12 and the second resin housing 13, filling a portion of the gap between the mating protrusions and recesses. Thus, the first resin housing 12 and the second resin housing 13 are bonded together by the encapsulation material 14. Furthermore, the encapsulation material 14 can also fill all the gaps between the protrusions and recesses.

[0061] <Effects>

[0062] Generally, adhesives are used to bond resin housings together. However, according to Embodiment 2, the first resin housing 12 and the second resin housing 13 can be bonded without adding a new step (the step of bonding with adhesive), thus reducing the processing and material costs required for bonding.

[0063] <Implementation Method 3>

[0064] <Structure>

[0065] Figure 6 This is a cross-sectional view showing an example of the structure of the semiconductor device according to Embodiment 3. For example... Figure 6As shown, the semiconductor device according to Embodiment 3 is characterized in that the first resin case has a first resin case 15 (including a predetermined first position at which the electrode terminals 10, 11 are fixed) corresponding to the portion around the electrode terminals 10, 11 and a first resin case 16 (a second position) corresponding to the other portion, and the first resin case 15 and the first resin case 16 are made of different resin materials. The other structures are the same as those of Embodiment 1, and thus detailed description thereof is omitted here.

[0066] As for the first resin case 12, the first resin case 15 has a higher glass transition temperature (Tg) than the first resin case 16. The surface distance and the space distance required for surface insulation of the semiconductor device are sufficient only with the first resin case 16.

[0067] The first resin case 15 and the first resin case 16 can also be formed by two-color molding of different resin materials. In addition, the first resin case 16 and the second resin case 13 can also be formed by two-color molding of different resin materials. As for the two two-color moldings, either one can be subjected to two-color molding, or both can be subjected to two-color molding.

[0068] Further, although the case where the first resin case has the first resin case 15 and the first resin case 16 has been described above, it is not limited thereto. The second resin case 13 can also have a structure having a portion around the electrode terminals 10, 11 and a portion other than the same (a second position).

[0069] <Effects>

[0070] By providing only the portion around the electrode terminals 10, 11, which requires heat resistance, with a resin having high heat resistance, it is possible to further reduce the material cost of the semiconductor device. In addition, by using two-color molding, it is possible to improve the manufacturing productivity of the semiconductor device and the case.

[0071] By selecting a resin material having high toughness and high strength for the portion around the electrode terminals 10, 11, it is possible to improve the resistance to stress generated at the bending process of the electrode terminals 10, 11 and at the installation of the bus bars to the electrode terminals 10, 11, and to reduce the risk of breakage of the case. In addition, it is possible to improve the manufacturing productivity of the semiconductor device and the case.

[0072] <Embodiment 4>

[0073] <Structure>

[0074] Figure 7 is a cross-sectional view showing one example of the structure of the semiconductor device according to Embodiment 4. As shown, the semiconductor device according to Embodiment 4 is characterized in that the first resin case has a first resin case 15 (including a predetermined first position at which the electrode terminals 10, 11 are fixed) corresponding to the portion around the electrode terminals 10, 11 and a first resin case 16 (a second position) corresponding to the other portion, and the first resin case 15 and the first resin case 16 are made of different resin materials. The other structures are the same as those of Embodiment 1, and thus detailed description thereof is omitted here. Figure 7As shown, the semiconductor device according to Embodiment 4 is characterized in that the electrode terminals 10, 11 are fixed to the second resin case 13 by insert molding. The other structures are the same as those of Embodiment 1, and thus detailed description thereof is omitted here.

[0075] In Figure 7 In the example, the electrode terminals 10, 11 are fixed to the second resin case 13 by insert molding, but are not limited thereto. For example, the electrode terminals 10, 11 can also be fixed to the first resin case 12 by insert molding.

[0076] The semiconductor chip 8 is a wide bandgap semiconductor such as SiC or GaN. In addition, the semiconductor chip 8 can also be a combination of any of IGBT, MOSFET, diode, and the like.

[0077] The electrode terminals 10, 11 are joined to the upper surface electrode pattern 5 of the insulating substrate 3 by ultrasonic joining (ultrasonic welding).

[0078] <Effects>

[0079] By insert molding the electrode terminals 10, 11 to the second resin case 13, it is possible to fix the electrode terminals 10, 11 and the insulating substrate 3 in advance. Thus, compared to the case where the electrode terminals 10, 11 and the insulating substrate 3 are combined separately, it is possible to reduce the fluctuation in position.

[0080] In the case where ultrasonic joining (ultrasonic welding) is used as the joining method of the electrode terminals 10, 11 and the insulating substrate 3, it is important to perform the alignment of the electrode terminals 10, 11 and the insulating substrate 3 with high precision, and in the case where the electrode terminals 10, 11 and the insulating substrate 3 are combined separately, a positioning process using a fixing tool is required. According to Embodiment 4, it is possible to realize the position fixation of the electrode terminals 10, 11 by the second resin case 13 in the manufacturing process of the semiconductor device, and positioning using a tool is not required. Thus, it is possible to use ultrasonic joining without increasing the man-hours of the manufacturing process of the semiconductor device.

[0081] Further, in the past, solder joining has been mainly used as the joining method of the electrode terminals and the insulating substrate, but by using ultrasonic joining, a plurality of advantages such as the following (A) to (D) are obtained compared to solder joining.

[0082] (A) Since a low melting point material such as solder is not used, it is possible to make the joined portion of the electrode terminals and the insulating substrate highly heat resistant.

[0083] (B) Since ultrasonic joining is solid phase diffusion of metals to each other, the joining strength is high, and it is possible to improve the reliability and quality of the joined portion.

[0084] (C) With the reliability of the joint improved, the area required for the joint can be reduced. Thus, the degree of freedom in the design of the semiconductor device is improved.

[0085] (D) In soldering, a cleaning process after the joint is required to remove flux residue. On the other hand, in ultrasonic joining, the joint does not need to be cleaned, and the production rate of the semiconductor device is improved.

[0086] By using a wide bandgap semiconductor chip that dissipates heat at high temperatures as the semiconductor chip 8, the semiconductor device can be made to have a large current and to operate at high temperatures, which can contribute to the energy saving of the semiconductor device. In addition, by using a high-heat-resistant first resin case 12 and a second resin case 13 with Tg≥100°C (more preferably 175°C), the electrodes 10 and 11 are joined to the insulating substrate 3 using ultrasonic joining, and thus the heat resistance of the semiconductor device is improved, and the semiconductor device can be further made to have a large current, to operate at high temperatures, and to save energy.

[0087] <Embodiment 5>

[0088] <Structure>

[0089] Figure 8 is a cross-sectional view showing one example of the structure of the semiconductor device according to Embodiment 5. As shown in Figure 8 , the semiconductor device according to Embodiment 5 is characterized in that the first resin case 12 and the second resin case 13 are fixed by an insulating adhesive. The other structure is the same as that of Embodiment 1, and thus a detailed description is omitted here.

[0090] <Effects>

[0091] Even in the design, the second resin case 13 is a structure that can become the shortest path of the surface distance in the surface insulation of the semiconductor device, and the insulating property can be ensured by interposing an insulating material in the middle of the path. Thus, the degree of freedom in the design of the case can be further improved.

[0092] <Embodiment 6>

[0093] Embodiment 6 is an application of the semiconductor device according to Embodiments 1 to 5 to a power conversion device. The application of the semiconductor device according to Embodiments 1 to 5 is not limited to a specific power conversion device, but in the following, a case in which the semiconductor device according to Embodiments 1 to 5 is applied to a three-phase inverter is described.

[0094] Figure 9 is a block diagram showing the structure of a power conversion system to which the power conversion device according to Embodiment 6 is applied.

[0095] Figure 9 The illustrated power conversion system is composed of a power supply 100, a power conversion device 200, and a load 300. The power supply 100 is a direct-current power supply that supplies direct current to the power conversion device 200. The power supply 100 can be composed of various power supplies, for example, can be composed of a direct-current system, a solar cell, and a storage battery, or can be composed of a rectification circuit or an AC / DC converter connected to an alternating-current system. In addition, the power supply 100 can also be composed of a DC / DC converter that converts direct current output from a direct-current system into prescribed power.

[0096] The power conversion device 200 is a three-phase inverter connected between the power supply 100 and the load 300, and converts direct current supplied from the power supply 100 into alternating current, and supplies the alternating current to the load 300. The power conversion device 200 is as illustrated in FIG. 1, and has a main conversion circuit 201 that converts direct current into alternating current and outputs the alternating current, a drive circuit 203 that outputs a drive signal that drives each switching element of the main conversion circuit 201, and a control circuit 204 that outputs a control signal that controls the drive circuit 203 to the drive circuit 203. Figure 9 The main conversion circuit 201 has a semiconductor device 202. The semiconductor device 202 corresponds to the semiconductor device related to Embodiments 1 to 5.

[0097] The load 300 is a three-phase motor that is driven by alternating current supplied from the power conversion device 200. In addition, the load 300 is not limited to a specific use, and is a motor mounted on various electric appliances, for example, is used as a motor for a hybrid bicycle, an electric automobile, a railway vehicle, an elevator, or an air conditioning device.

[0098] Hereinafter, details of the power conversion device 200 will be described. The main conversion circuit 201 has switching elements and freewheeling diodes, and converts direct current supplied from the power supply 100 into alternating current by switching of the switching elements, and supplies the alternating current to the load 300. The specific circuit structure of the main conversion circuit 201 is various, but the main conversion circuit 201 related to Embodiment 6 is a 2-level three-phase full-bridge circuit, and can be composed of six switching elements and six freewheeling diodes respectively connected in antiparallel to the switching elements. Each switching element of the main conversion circuit 201 applies the semiconductor device related to any one of the above-described Embodiments 1 to 5. The six switching elements are connected in series two by two to constitute upper and lower arms, and each of the upper and lower arms constitutes each phase (U phase, V phase, W phase) of the full-bridge circuit. Furthermore, output terminals of each of the upper and lower arms, that is, three output terminals of the main conversion circuit 201 are connected to the load 300.

[0099] The drive circuit 203 generates a drive signal that drives the switching element of the main conversion circuit 201, and supplies the drive signal to the control electrode of the switching element of the main conversion circuit 201. Specifically, the drive circuit 203 outputs, to the control electrode of each switching element, a drive signal that causes the switching element to be in an on state and a drive signal that causes the switching element to be in an off state, in accordance with a control signal from the control circuit 204. In a case where the switching element is to be maintained in the on state, the drive signal is a voltage signal that is greater than or equal to the threshold voltage of the switching element (an on signal), and in a case where the switching element is to be maintained in the off state, the drive signal is a voltage signal that is less than or equal to the threshold voltage of the switching element (an off signal).

[0100] The control circuit 204 controls the switching elements of the main conversion circuit 201 to supply a desired electric power to the load 300. Specifically, the control circuit 204 calculates the time (on time) during which each switching element of the main conversion circuit 201 should be in an on state, on the basis of the electric power that should be supplied to the load 300. For example, the main conversion circuit 201 can be controlled by PWM control that modulates the on time of the switching element in correspondence with the voltage that should be output. Furthermore, the control circuit 204 outputs a control command (control signal) to the drive circuit 203 so that the on signal is output to the switching element that should be in an on state and the off signal is output to the switching element that should be in an off state at each point in time. The drive circuit 203 outputs the on signal or the off signal as a drive signal to the control electrode of each switching element, in accordance with the control signal.

[0101] In the power conversion device according to Embodiment 6, the semiconductor device according to any one of Embodiments 1 to 5 is used as the switching element of the main conversion circuit 201, and thus cost reduction and energy saving of the power conversion device can be achieved.

[0102] In Embodiment 6, an example in which the semiconductor device according to any one of Embodiments 1 to 5 is applied to a 2-level three-phase inverter is described, but the application of the semiconductor device according to any one of Embodiments 1 to 5 is not limited to this, and the semiconductor device according to any one of Embodiments 1 to 5 can be applied to various power conversion devices. In Embodiment 6, although a 2-level power conversion device is described as one example, it can also be a 3-level or a multi-level power conversion device, and the semiconductor device according to any one of Embodiments 1 to 5 can be applied to a single-phase inverter in a case where electric power is supplied to a single-phase load. In addition, in a case where electric power is supplied to a direct-current load or the like, the semiconductor device according to any one of Embodiments 1 to 5 can be applied to a DC / DC converter or an AC / DC converter.

[0103] In addition, the power conversion device to which the semiconductor device according to Embodiments 1 to 5 is applied is not limited to the case where the load is a motor, and can be used as a power supply device for an electric discharge machine, a laser machine, an induction heating cooking machine, or a non-contact power feeding system, for example, and can also be used as a power conditioner for a solar power generation system or an electric storage system.

[0104] <Embodiment 7>

[0105] Figure 10 is a view showing one example in which the power conversion device according to Embodiment 6 is applied to a mobile body. As shown in Figure 10 , the mobile body 400 is equipped with the power conversion device 200 described in Embodiment 6.

[0106] According to Embodiment 7, cost reduction and energy saving of the mobile body can be achieved.

[0107] Furthermore, each of the embodiments can be freely combined, or appropriately modified or omitted, within the scope of the present application.

[0108] While the present application has been described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is understood that numerous modifications and variations can be devised without departing from the scope of the application.

[0109] Explanation of Reference Numerals

[0110] 1 base plate, 2 bonding material, 3 insulating substrate, 4 ceramic substrate, 5 upper surface electrode pattern, 6 lower surface electrode pattern, 7 bonding material, 8 semiconductor chip, 9 metal wire, 10 electrode terminal, 11 electrode terminal, 12 first resin case, 13 second resin case, 14 encapsulation material, 15 first resin case, 16 first resin case, 17 insulating adhesive, 100 power supply, 200 power conversion device, 201 main conversion circuit, 202 semiconductor device, 203 drive circuit, 204 control circuit, 300 load, 400 mobile body.

Claims

1. A semiconductor device having: a base plate; an insulating substrate provided on the base plate; a semiconductor chip provided on the insulating substrate; a first resin case and a second resin case installed on the base plate in a manner of housing the insulating substrate and the semiconductor chip inside, the first resin case and the second resin case being fitted to each other; and a sealing material sealing the insulating substrate and the semiconductor chip, the first resin case and the second resin case being composed of resin materials different in relative tracking index, the semiconductor device further having an electrode terminal provided on the insulating substrate and fixed to the first resin case, the second resin case being directly installed on the base plate, the first resin case being fixed to the base plate via the second resin case, the relative tracking index of the first resin case being higher than that of the second resin case.

2. The semiconductor device according to claim 1, wherein the first resin case and the second resin case are fitted to each other in a concave-convex structure, and the sealing material fills at least a part of the concave-convex structure.

3. The semiconductor device according to claim 1, wherein a surface insulation required distance and a space insulation required distance of at least one of the first resin case and the second resin case are sufficient only with the first resin case or the second resin case.

4. The semiconductor device according to claim 3, wherein the first resin case in which the electrode terminal is fixed has a first portion containing a position where the electrode terminal is fixed and a second portion other than the first portion, and the first portion and the second portion are composed of different resin materials.

5. The semiconductor device according to claim 3, wherein the electrode terminal is fixed to the first resin case by insert molding.

6. The semiconductor device according to claim 3, wherein the insulating substrate and the electrode terminal are joined by ultrasonic bonding.

7. The semiconductor device according to claim 1, wherein the first resin case and the second resin case are fixed by an insulating adhesive.

8. The semiconductor device according to claim 1, wherein the first resin case and the second resin case are composed of resin materials having a glass transition temperature of greater than or equal to 100°C.

9. The semiconductor device according to claim 8, wherein the insulating substrate and the electrode terminal are subjected to ultrasonic bonding.

10. The semiconductor device according to claim 1, wherein the first resin case and the second resin case are snap-fitted.

11. The semiconductor device according to claim 1, wherein the first resin case and the second resin case are composed of two-color molding.

12. The semiconductor device according to any one of claims 1 to 11, wherein the semiconductor chip is composed of a wide bandgap semiconductor.

13. A power conversion device having: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ a main conversion circuit having the semiconductor device according to any one of claims 1 to 12, and outputting a converted power from input power; a drive circuit outputting a drive signal for driving the semiconductor device to the semiconductor device; and a control circuit outputting a control signal for controlling the drive circuit to the drive circuit.

14. A moving object having the power conversion device according to claim 13.

Images