Semiconductor device, power conversion device

Abstract

To provide a semiconductor device in which heat generated by bonding at a terminal is difficult to be transmitted to a semiconductor element.SOLUTION: A semiconductor device 4 includes a plate-shaped conductor 8 having a first thickness, an insulator 60 that seals a portion of the conductor 8, a semiconductor element 64a sealed in the insulator 60 and electrically connected to a part of the conductor 8, and a terminal 9 connected to the conductor 8 outside the insulator 60, and a distance a along the conductor 8 from the portion 7 where the conductor 8 and the terminal 9 are joined to the insulator 60 toward the semiconductor element 64a is larger than the first thickness t.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] 2. Description of the Related Art Techniques have been proposed for suppressing a decrease in reliability of semiconductor devices and power conversion devices incorporating the semiconductor devices.

[0003] For example, a semiconductor module has a semiconductor unit and a case that houses the semiconductor unit, and the case includes a power terminal. A connecting member electrically connects the semiconductor module and a capacitor and mechanically connects them. The back surface of the connecting member is placed on the power terminal, and the connecting member is joined to the power terminal by a weld that penetrates from the front surface to the back surface. By controlling the penetration depth of the weld, thermal damage to the joined portion on the opposite side to the connecting member is suppressed. Such a technology is disclosed, for example, in Patent Document 1 listed below. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-6876 Summary of the Invention [Problem to be solved by the invention]

[0005] It is believed that preventing the heat generated when joining a conductor electrically connected to a semiconductor element to a terminal from being transferred to the semiconductor element through thermal conduction of the conductor will contribute to improving the reliability of the semiconductor device and, ultimately, the power conversion device.

[0006] The present disclosure aims to make it difficult for heat generated by bonding at the terminals to be transferred to the semiconductor element. [Means for solving the problem]

[0007] According to the present disclosure of the first aspect The semiconductor device includes a plate-shaped conductor having a first thickness, an insulator that seals a portion of the conductor, a semiconductor element sealed in the insulator and electrically connected to the portion, and a terminal that is joined to the conductor outside the insulator, and the length along the conductor from the portion where the conductor and the terminal are joined toward the semiconductor element to the insulator is greater than the first thickness. The terminal has a first portion that contacts and is joined to the conductor, and a second portion that is connected to the first portion and bent relative to the first portion. The terminal is a press-fit terminal that has an insertion portion on the second portion opposite the first portion. [Effects of the Invention]

[0008] According to the semiconductor device of the present disclosure, heat generated by the bonding at the terminals is not easily transferred to the semiconductor element. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view illustrating a configuration of a semiconductor device according to a first embodiment. [Figure 2] 1 is a perspective view illustrating a part of the configuration of a semiconductor device according to a first embodiment. [Figure 3] 3 is a plan view illustrating a connection between a conductor and a semiconductor element according to the first embodiment. FIG. [Figure 4] FIG. 10 is a cross-sectional view showing a first example of the configuration of a semiconductor device according to a second embodiment. [Figure 5] FIG. 10 is a cross-sectional view showing a second example of the configuration of the semiconductor device according to the second embodiment. [Figure 6] FIG. 10 is a cross-sectional view showing a third example of the configuration of the semiconductor device according to the second embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing a first example of the configuration of a semiconductor device according to a third embodiment. [Figure 8] FIG. 10 is a cross-sectional view showing a second example of the configuration of the semiconductor device according to the third embodiment. [Figure 9] FIG. 10 is a cross-sectional view illustrating the configuration of a semiconductor device according to a fourth embodiment. [Figure 10]10 is a perspective view illustrating an example of the appearance of a semiconductor module and a conductor used in a semiconductor device according to a fifth embodiment. FIG. [Figure 11] FIG. 10 is a perspective view illustrating an example of the appearance of a semiconductor device according to a fifth embodiment. [Figure 12] FIG. 12 is a cross-sectional view of the semiconductor device taken along the line HH in FIG. [Figure 13] FIG. 13 is a block diagram showing a configuration of a power conversion system to which a power conversion device according to an eighth embodiment is applied. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiment 1 Fig. 1 is a cross-sectional view illustrating a configuration of a semiconductor device 4 according to the first embodiment. Fig. 2 is a perspective view illustrating a part of the configuration of the semiconductor device 4 according to the first embodiment.

[0011] The semiconductor device 4 has a semiconductor module 6, a conductor 8, and a terminal 9. Fig. 2 shows the conductor 8 and the terminal 9, and a part of the semiconductor module 6 in the vicinity of the conductor 8 and the terminal 9. The terminal 9 may have a hole 90 on the side opposite to the semiconductor module 6 (see Fig. 2). However, the hole 90 is not shown in Fig. 1.

[0012] The semiconductor module 6 has a semiconductor element 64a and an insulator 60. The insulator 60 functions as a sealant that seals the semiconductor element 64a and a portion 8a of the conductor 8. In FIG. 1, the reference numeral for the portion 8a has been omitted to improve visibility.

[0013] For example, epoxy resin is used for the insulator 60. For example, the insulator 60 has a structure in which a gel is enclosed in a case (housing) made of polyphenylene sulfide (PPS) or polyethylene terephthalate (PET), and the gel seals the portion 8a and the semiconductor element 64a.

[0014] The portion 8a and the semiconductor element 64a are electrically connected, for example, via a wiring 63. The wiring 63 is made of, for example, aluminum. Using a bonding wire for the wiring 63 increases the degree of freedom in the layout of the semiconductor element 64a and the conductor 8, and contributes to miniaturization of the semiconductor device 4.

[0015] The conductor 8 is plate-shaped and has a thickness t. For ease of explanation, the thickness direction of the conductor 8 is taken as direction Z. The direction of the conductor 8 from the outside of the insulator 60 toward the portion 8a is taken as direction X. Direction X differs from direction Z, and typically direction X is perpendicular to direction Z. In the following explanation, direction Y is introduced, which is perpendicular to direction X and direction Z and forms a so-called right-handed coordinate system.

[0016] The conductor 8 and the terminal 9 are formed using a material with low electrical resistance, such as copper. The terminal 9 is joined to the conductor 8 outside the insulator 60. The conductor 8 and the terminal 9 are joined at the portion 7. The joining of the conductor 8 and the terminal 9 is achieved by, for example, laser joining or soldering using a soldering iron. The insulator 60 has an end face 60g on the portion 7 side.

[0017] FIG. 2 illustrates an example in which laser welding is performed from the terminal 9 side, resulting in the region 7 exposing the surface 7a from the terminal 9 (unlike FIG. 1). The fact that the conductor 8 and the terminal 9 are joined by, for example, laser welding contributes to the miniaturization of the semiconductor device 4. Laser welding generates a large amount of heat locally, but structural features reduce the impact of this heat on the semiconductor module 6 via the conductor 8. These features include the fact that the distance a, which is the length along the conductor 8 from the region 7 toward the semiconductor element 64a to the insulator 60 (in accordance with FIG. 1, between the region 7 and the end face 60g), is greater than the thickness t. The advantages of these features will be described in detail later.

[0018] For example, the semiconductor module 6 has a plate-shaped conductor 61, a semiconductor element 64b, and bonding materials 62a and 62b. The conductor 61 is connected to the semiconductor element 64a via the bonding material 62a, and is connected to the semiconductor element 64b via the bonding material 62b. For example, the bonding material 62a and the conductor 61 are connected to the semiconductor element 64a on the same side (the Z direction side in the example of FIG. 1) with respect to the semiconductor element 64a.

[0019] For example, the semiconductor module 6 has bonding materials 65a and 65b, a circuit pattern 66, and an insulating layer 67. The circuit pattern 66 is provided on the insulating layer 67 on the side of the semiconductor elements 64a and 64b.

[0020] The circuit pattern 66 is connected to the semiconductor element 64a via the bonding material 65a, and is connected to the semiconductor element 64b via the bonding material 65b. For example, the bonding material 62a and the bonding material 65a are located on opposite sides of the semiconductor element 64a. For example, the bonding material 62b and the bonding material 65b are located on opposite sides of the semiconductor element 64a. For example, the circuit pattern 66 and the conductor 61 sandwich the semiconductor elements 64a and 64b in the Z direction.

[0021] The insulating layer 67 is made of, for example, resin or ceramic. The conductor 61 and the circuit pattern 66 are made of a material with low electrical resistance, for example, copper. The bonding materials 62a, 62b, 65a, and 65b are made of, for example, solder or silver.

[0022] For example, the semiconductor module 6 has a conductor foil 68. The conductor foil 68 is provided on the insulating layer 67 on the opposite side to the circuit pattern 66.

[0023] The insulator 60 seals the semiconductor element 64b, the bonding materials 62a, 62b, 65a, and 65b, the circuit pattern 66, and the insulating layer 67. The insulator 60 seals at least the insulating layer 67 side of the conductor foil 68 and at least the portions of the conductor 61 that are bonded to the bonding materials 62a and 62b.

[0024] In the insulator 60, at least a portion of the conductor foil 68 on the side opposite to the insulating layer 67 is exposed to the outside of the insulator 60. For example, Fig. 1 illustrates a case where the side of the conductor foil 68 opposite to the direction Z is exposed.

[0025] The insulator 60 exposes at least a part of the conductor 61 to the outside of the insulator 60. For example, Fig. 1 shows an example in which the direction X side of the conductor 61 is exposed.

[0026] For example, the semiconductor device 4 has a cooler 51 and a bonding material 52. The insulator 60 does not seal the cooler 51. The bonding material 52 bonds the cooler 51 to the conductor foil 68 exposed from the insulator 60. The cooler 51 is formed using a material with high thermal conductivity, such as aluminum or copper. The bonding material 52 is made of, for example, solder or silver.

[0027] 3 is a plan view illustrating the connection between the conductor 8 and the semiconductor element 64a. Holes 90 are also omitted from FIG. 3. The semiconductor element 64a has a control unit 641. The wiring 63 electrically connects the portion 8a to the control unit 641. A bonding wire is used for the wiring 63, and connecting the portion 8a to the control unit 641 allows for efficient placement of the wiring 63, improving the degree of freedom in the internal layout of the semiconductor module 6 and ultimately contributing to the miniaturization of the semiconductor device 4.

[0028] When joining terminal 9 and conductor 8, the heat generated at the joining point varies greatly depending on the joining method. For example, if copper is used as the material for terminal 9 and keyhole welding is performed with a laser, the temperature of the joined area will exceed the melting point of copper (1000°C or higher), albeit locally and momentarily.

[0029] Suppressing the transfer of heat generated by the joining to the insulator 60 and the elements that the insulator 60 seals through the conductor 8 is desirable from the viewpoint of reliability of the semiconductor module 6 and, ultimately, the semiconductor device 4.

[0030] To achieve this suppression, it is desirable to increase the distance from the portion 7 to the insulator 60 or the element sealed by the insulator 60 and to reduce the thickness t of the conductor 8 to make it less susceptible to heat transfer. Simply lengthening the conductor 8 to move the portion 7 away from the insulator 60 would increase the space occupied by the conductor 8, and ultimately the semiconductor module 6 and the semiconductor device 4.

[0031] Although reducing the width B, which is the length of the conductor 8 along the direction Y, contributes to the above-mentioned suppression, it reduces the area of ​​the portion 7 in a plan view. Such a reduction may lead to a decrease in the strength of the joint between the conductor 8 and the terminal 9, a decrease in mechanical reliability, and a decrease in electrical reliability.

[0032] Introducing width B' as the length of terminal 9 along direction Y, thickness t' as the length of terminal 9 along direction Z, amount of heat Qo applied to portion 7 during joining, amount of heat Q transferred from portion 7 to insulator 60, amount of heat Q' transferred from portion 7 to tip 9a on the opposite side of terminal 9 from insulator 60 (opposite side of direction X), temperature To of portion 7 during joining, temperature T of insulator 60, and temperature T' of tip 9a (see Figure 2), the following equation is established.

[0033] Q∝(To-T)*B*(t / a)…(1) Q'∝(To-T')*B'*t'…(2) Q = Qo - Q'...(3)

[0034] From equation (3), one idea to suppress the heat quantity Q is to increase the heat quantity Q'. However, during joining, T' > T, and (To - T') on the right side of equation (2) is smaller than (To - T) on the right side of equation (1). Therefore, increasing the heat quantity Q' is not realistic. For the same reason, the influence of width B' and thickness t' on the heat quantity Q is small.

[0035] For these reasons, the width B, thickness t, and distance a in equation (1) are parameters that have a significant effect on the heat quantity Q. From the perspective of obtaining sufficient bonding strength, it is desirable to increase the area of ​​the portion 7 in a plan view. Therefore, it is not realistic to reduce the widths B and B'.

[0036] In this way, the above-described feature that the distance a is greater than the thickness t suppresses the amount of heat transferred to the semiconductor module 6. Heat generated by the bonding at the terminals 9 is less likely to be transferred to the semiconductor element 64a, improving the reliability of the semiconductor element 64a and, ultimately, the semiconductor device 4.

[0037] Embodiment 2 4 is a cross-sectional view showing a first example of the configuration of the semiconductor device 4 according to the second embodiment. The semiconductor module 6 and the conductor 8 of the semiconductor device 4 according to the second embodiment are configured similarly to the semiconductor module 6 and the conductor 8 of the semiconductor device 4 according to the first embodiment. The semiconductor device 4 according to the second embodiment has a terminal 91 instead of the terminal 9 of the semiconductor device 4 according to the first embodiment.

[0038] Terminal 91 has a first portion 91a and a second portion 91b. First portion 91a contacts conductor 8 and is joined to conductor 8. For example, first portion 91a contacts conductor 8 on the direction Z side of conductor 8. Region 7 is located, for example, between first portion 91a and conductor 8. When laser joining is used to join first portion 91a and conductor 8, surface 7a is exposed from terminal 9, as illustrated in FIG. 2 .

[0039] The second portion 91b is connected to the first portion 91a and bent relative to the first portion 91a. For example, in the semiconductor device 4 according to the first example of the second embodiment, the second portion 91b is farther from the semiconductor module 6 than the first portion 91a. For example, the second portion 91b extends from the first portion 91a in a direction away from the conductor 8 (direction Z in FIG. 4).

[0040] Compared to terminal 9, terminal 91 has improved layout freedom for its conductor 8, and therefore for the semiconductor module 6. This improvement contributes to the miniaturization of the semiconductor device 4. Due to the presence of second portion 91b, terminal 91 can be made larger in volume than terminal 9. This increase in volume leads to an increase in the heat capacity of terminal 91, and an increase in the amount of heat transferred to terminal 91 from portion 7. The increase in the amount of heat transferred to terminal 91 contributes to suppressing the amount of heat transferred to the semiconductor module 6, and therefore the amount of heat transferred to semiconductor element 64a (see formula (3)).

[0041] 5 is a cross-sectional view showing a second example of the configuration of the semiconductor device 4 according to embodiment 2. In the semiconductor device 4 according to the second example of embodiment 2, the first portion 91a and the second portion 91b are connected closer to the semiconductor module 6 than the portion 7, and therefore closer to the semiconductor element 64a than the portion 7.

[0042] The second example is advantageous over the first example in that the relationship a>t can be easily obtained, and furthermore, the second example is advantageous in that the conduction of heat to the semiconductor module 6 and further to the semiconductor element 64a can be easily suppressed.

[0043] 6 is a cross-sectional view showing a third example of the configuration of the semiconductor device 4 according to the second embodiment. The third example of the second embodiment is the second example of the second embodiment, and further has a feature that the first portion 91a has an end face 91c on the conductor 8 on the side opposite to the second portion 91b. Compared to the second example in which the end face 91c is spaced apart from the conductor 8 as viewed from the semiconductor module 6, the third example contributes to the miniaturization of the semiconductor device 4 in addition to the effects of the second example.

[0044] Embodiment 3 In the semiconductor device 4 of the third embodiment, as in the second and third examples of the semiconductor device 4 of the second embodiment, a terminal 91 is adopted, the first portion 91a is joined to the conductor 8, and the first portion 91a and the second portion 91b are connected closer to the semiconductor element 64a than the portion 7.

[0045] In the semiconductor device 4 according to the third embodiment, the second portion 91b sandwiches the conductor 8 between itself and the insulator 60 in the direction Z, which is the direction in which the conductor 8 indicates the thickness t as a length.

[0046] Fig. 7 is a cross-sectional view showing a first example of the configuration of the semiconductor device 4 according to the third embodiment. Fig. 7 illustrates a case where the end face 91c is located on the conductor 8, similar to the third example of the semiconductor device 4 according to the second embodiment. The end face 91c may be located away from the conductor 8 when viewed from the semiconductor module 6.

[0047] 7 illustrates a case in which the insulator 60 has an inside corner 60d, and the second portion 91b sandwiches the conductor 8 between the insulator 60 and the second portion 91b in the direction Z at the inside corner 60d. The fact that the second portion 91b is located at a position where the conductor 8 is sandwiched between the insulator 60 and the second portion 91b reduces the length by which the conductor 8 protrudes from the insulator 60, which in turn contributes to the miniaturization of the semiconductor device 4. The presence of the inside corner 60d contributes to the second portion 91b sandwiching the conductor 8 between the insulator 60 and the second portion 91b.

[0048] Even when insulator 60 has inside corner 60d, distance a is the length along conductor 8 from portion 7 toward semiconductor element 64a to insulator 60. Therefore, in the first example of the configuration of semiconductor device 4 according to embodiment 3, distance a is the length along conductor 8 between portion 7 and end face 60g, as in embodiments 1 and 2.

[0049] 8 is a cross-sectional view showing a second example of the configuration of the semiconductor device 4 according to the third embodiment. In the second example of the configuration of the semiconductor device 4 according to the third embodiment, the portion 7 is aligned with the insulator 60 along the direction Z. Such an arrangement of the portion 7 reduces the length by which the conductor 8 protrudes from the insulator 60, which in turn contributes to the miniaturization of the semiconductor device 4.

[0050] Even when region 7 is aligned with insulator 60 along direction Z, distance a is the length along conductor 8 from region 7 toward semiconductor element 64a to insulator 60. Therefore, in this case, distance a is not the length along conductor 8 between region 7 and end face 60g. In this case, distance a is the length between region 7 and the end face where insulator 60 appears on the region 7 side at inside corner 60d (the surface where the tip of the lead wire indicating inside corner 60d comes into contact in FIG. 8).

[0051] In the second example of the configuration of the semiconductor device 4 according to the third embodiment, the insulator 60 is located directly below the portion 7 (on the opposite side of the direction Z), and therefore the temperature of the insulator 60 is likely to rise. However, the heat transfer to the semiconductor element 64a passes through the conductor 8, and is therefore suppressed by the relationship a>t as described above.

[0052] Considering the influence of heat transferred to the insulator 60 itself, the conductor 8 and the terminal 91 are joined by a joining method that results in a relatively low temperature during joining, such as soldering with an iron. For example, a highly heat-resistant material is used for the insulator 60.

[0053] Embodiment 4 9 is a cross-sectional view illustrating the configuration of a semiconductor device 4 according to a fourth embodiment. 4 In the semiconductor device 4 according to the present embodiment, a terminal 92 is employed instead of the terminal 91 employed in the semiconductor device 4 according to the second embodiment.

[0054] Terminal 92 has a first portion 91a and a second portion 91b, similar to terminal 91. Terminal 92 is a press-fit terminal in which second portion 91b has an insertion portion 92c on the side opposite to first portion 91a.

[0055] 9 illustrates a case in which the first portion 91a and the second portion 91b are coupled closer to the semiconductor element 64a than the portion 7, similarly to the second example of the semiconductor device 4 according to the second embodiment and the semiconductor device 4 according to the third embodiment. In a case in which the first portion 91a and the second portion 91b are coupled farther from the semiconductor element 64a than the portion 7 (see FIG. 4), the second portion 91b may have an insertion portion 92c on the opposite side to the first portion 91a.

[0056] The insertion portion 92c is inserted into an object (received portion) not shown, and contributes to electrical continuity between the object and the terminal 92, and further between the semiconductor element 64a via the conductor 8 and the wiring 63. The insertion portion 92c contributes to mechanical fixation between the object and the terminal 92, and further between the object and the semiconductor module 6 via the conductor 8. The use of the terminal 92, which is a press-fit terminal, contributes to a wider range of assembly options in a power conversion device (exemplified later) that incorporates the semiconductor device 4, improves the degree of freedom in arranging the semiconductor device 4, and ultimately contributes to the miniaturization of a unit in which the power conversion device is used.

[0057] Embodiment 5. Fig. 10 is a perspective view illustrating an example of the appearance of a semiconductor module 6 and a conductor 8 included in a semiconductor device 4 according to embodiment 5. Fig. 11 is a perspective view illustrating an example of the appearance of a semiconductor device 4 according to embodiment 5. Fig. 12 is a cross-sectional view of the semiconductor device 4 taken along direction Y at position HH in Fig. 11.

[0058] The semiconductor device 4 according to the fifth embodiment has a terminal 93 instead of the above-described terminals 9, 91, and 92. The terminal 93 is joined to the conductor 8 at the portion .

[0059] Insulator 60 has irregularities 60b. Figures 10, 11, and 12 illustrate an example in which irregularities 60b appear on the direction Z side of conductor 8. These figures also illustrate an example in which insulator 60 also has inside corners 60d, but the presence of inside corners 60d is not essential to embodiment 5.

[0060] The irregularities 60b have recesses 60e and protrusions 60f. The recesses 60e are recessed relative to the main end surface 60a of the insulator 60 in the direction Z. For example, the recesses 60e are continuous with the inside corners 60d. The protrusions 60f protrude from the recesses 60e, for example, in the direction Z.

[0061] The terminal 93 has a recess 93a into which the protrusion 60f fits. For example, the recess 93a is a hole that penetrates the terminal 93, and when the terminal 93 is joined to the conductor 8, the protrusion 60f is exposed from the recess 93a.

[0062] In the fifth embodiment, the distance a is also described as the length along the conductor 8 from the portion 7 toward the semiconductor element 64a to the insulator 60. Specifically, for example, the distance a is the length between the portion 7 and the end face 60g of the insulator 60 on the portion 7 side.

[0063] The fitting of the protrusion 60f and the recess 93a improves the positioning accuracy of the terminal 93, stabilizes the quality of the joint at the portion 7, and ultimately contributes to miniaturization of the semiconductor device 4 and improvement of its reliability.

[0064] Embodiment 6 In any of the semiconductor devices 4 according to the first to fifth embodiments, the semiconductor element 64a includes, for example, a reverse conducting insulated gate bipolar transistor (RC-IGBT). For example, the semiconductor element 64a is a reverse conducting insulated gate bipolar transistor. Similarly, the semiconductor element 64b also includes a reverse conducting insulated gate bipolar transistor, and for example, the semiconductor element 64b may be a reverse conducting insulated gate bipolar transistor. Alternatively, the semiconductor element 64b may be omitted.

[0065] The semiconductor element 64a having a reverse conducting insulated gate bipolar transistor reduces the number of chips included in the semiconductor device 4, which in turn contributes to miniaturization of the semiconductor device 4.

[0066] Embodiment 7 In any of the semiconductor devices 4 according to the first to fifth embodiments, the semiconductor element 64a includes, for example, silicon carbide (SiC) as a semiconductor. Similarly, the semiconductor element 64b may also include silicon carbide (SiC) as a semiconductor.

[0067] The use of silicon carbide as a semiconductor reduces loss in the semiconductor device 4, which in turn contributes to making the semiconductor device 4 smaller and more dense.

[0068] Embodiment 8 In this embodiment, the semiconductor device 4 according to the first to seventh embodiments described above is applied to a power conversion device. Although the present disclosure is not limited to a specific power conversion device, a case where the present disclosure is applied to a three-phase inverter will be described.

[0069] FIG. 13 is a block diagram showing the configuration of a power conversion system to which the power conversion device according to this embodiment is applied.

[0070] The power conversion system shown in Fig. 13 is composed of a power supply 100, a power conversion device 200, and a load 300. The power supply 100 is a DC power supply and supplies DC power to the power conversion device 200. The power supply 100 can be composed of various components, such as a DC system, a solar cell, or a storage battery, or it may be composed of a rectifier circuit connected to an AC system or an AC / DC converter. Furthermore, the power supply 100 may be composed of a DC / DC converter that converts DC power output from a DC system into a specific power.

[0071] The power conversion device 200 is a three-phase inverter connected between the power source 100 and the load 300, and converts DC power supplied from the power source 100 into AC power and supplies the AC power to the load 300. As shown in Fig. 13 , the power conversion device 200 includes a main conversion circuit 201 that converts DC power into AC power and outputs it, a drive circuit 202 that outputs drive signals that drive each switching element of the main conversion circuit 201, and a control circuit 203 that outputs a control signal to the drive circuit 202 to control the drive circuit 202.

[0072] The load 300 is a three-phase electric motor driven by AC power supplied from the power conversion device 200. The load 300 is not limited to a specific application, but is an electric motor mounted on various electrical devices, and is used as an electric motor for, for example, a hybrid vehicle, an electric vehicle, a railroad car, an elevator, or an air conditioning device.

[0073] The power conversion device 200 will be described in detail below. The main conversion circuit 201 includes switching elements and freewheel diodes (not shown). The switching elements convert DC power supplied from the power supply 100 into AC power, which is supplied to the load 300. The main conversion circuit 201 can have a variety of specific circuit configurations. However, the main conversion circuit 201 according to this embodiment is a two-level, three-phase full-bridge circuit that can be configured with six switching elements and six freewheel diodes connected in anti-parallel to each switching element. Each switching element of the main conversion circuit 201 is a semiconductor device 4 according to any one of the first to seventh embodiments. Two of the six switching elements are connected in series to form upper and lower arms, and each upper and lower arm forms one phase (U phase, V phase, W phase) of the full-bridge circuit. The output terminals of each upper and lower arm, i.e., the three output terminals of the main conversion circuit 201, are connected to the load 300.

[0074] The drive circuit 202 generates drive signals for driving the switching elements of the main conversion circuit 201 and supplies them to the control electrodes of the switching elements of the main conversion circuit 201. Specifically, the drive circuit 202 outputs to the control electrodes of each switching element a drive signal that turns the switching element on and a drive signal that turns the switching element off, in accordance with a control signal from a control circuit 203 (described later). When maintaining a switching element in the on state, the drive signal is a voltage signal (on signal) that is equal to or higher than the threshold voltage of the switching element, and when maintaining a switching element in the off state, the drive signal is a voltage signal (off signal) that is equal to or lower than the threshold voltage of the switching element.

[0075] The control circuit 203 controls the switching elements of the main conversion circuit 201 so that the desired power is supplied to the load 300. Specifically, it calculates the time (on time) that each switching element of the main conversion circuit 201 should be in the on state based on the power to be supplied to the load 300. For example, the main conversion circuit 201 can be controlled by PWM control, which modulates the on time of the switching elements according to the voltage to be output. Then, the control circuit 203 outputs a control command (control signal) to the drive circuit 202 so that an on signal is output to a switching element that should be in the on state at each time point, and an off signal is output to a switching element that should be in the off state at each time point. In accordance with this control signal, the drive circuit 202 outputs an on signal or an off signal as a drive signal to the control electrode of each switching element.

[0076] In the power conversion device according to the present embodiment, the semiconductor device 4 according to any one of the first to seventh embodiments is applied as a switching element of the main conversion circuit 201, and therefore the power conversion device is made smaller in size.

[0077] This embodiment is not limited to the case where the semiconductor device 4 is applied to the above-described two-level three-phase inverter, but also includes cases where the semiconductor device 4 is applied to various power conversion devices. In addition to the above-described two-level power conversion device, the semiconductor device 4 may be applied to a three-level or multi-level power conversion device, and when power is supplied to a single-phase load, the semiconductor device 4 may be applied to a single-phase inverter. Furthermore, when power is supplied to a DC load or the like, the semiconductor device 4 can also be applied to a DC / DC converter or an AC / DC converter.

[0078] Furthermore, the power conversion device to which the semiconductor device 4 is applied is not limited to a case where the load is an electric motor. For example, the power conversion device can be used as a power supply device that supplies power to an electric discharge machine, a laser processing machine, an induction heating cooker, or a contactless power supply system. The power conversion device can also be used as a power conditioner for a solar power generation system, a power storage system, or the like.

[0079] It should be noted that the embodiments can be freely combined, and each embodiment can be modified or omitted as appropriate.

[0080] Various aspects of the present disclosure are summarized below as appendices.

[0081] (Appendix 1) a plate-shaped conductor having a first thickness; an insulator that encapsulates a portion of the conductor; a semiconductor element sealed in the insulator and electrically connected to the part; a terminal joined to the conductor outside the insulator; Equipped with A semiconductor device, wherein the length along the conductor from the portion where the conductor and the terminal are joined toward the semiconductor element to the insulator is greater than the first thickness.

[0082] (Appendix 2) The terminal is a first portion in contact with the conductor and joined to the conductor; a second portion connected to the first portion and bent relative to the first portion; 2. The semiconductor device according to claim 1,

[0083] (Appendix 3) 3. The semiconductor device according to claim 2, wherein the terminal is a press-fit terminal having an insertion portion on the second portion opposite the first portion.

[0084] (Appendix 4) 3. The semiconductor device according to claim 2, wherein the first portion and the second portion are connected closer to the semiconductor element than the portion.

[0085] (Appendix 5) 5. The semiconductor device of claim 4, wherein the first portion has an end face on the conductor on the opposite side to the second portion.

[0086] (Appendix 6) the conductor has the first thickness along a first direction; 6. The semiconductor device of claim 5, wherein the second portion sandwiches the conductor between itself and the insulator in the first direction.

[0087] (Appendix 7) the insulator has an inside corner; 7. The semiconductor device of claim 6, wherein at the inside corner, the second portion sandwiches the conductor between itself and the insulator in the first direction.

[0088] (Appendix 8) 8. The semiconductor device of claim 7, wherein the portion is aligned with the insulator along the first direction.

[0089] (Appendix 9) The insulator has a protrusion, 9. The semiconductor device according to claim 1, wherein the terminal has a recess that fits into the protrusion.

[0090] (Appendix 10) a bonding wire connecting the part to the semiconductor element; 10. The semiconductor device according to any one of claims 1 to 9, further comprising:

[0091] (Appendix 11) the semiconductor device has a control unit, 11. The semiconductor device according to claim 10, wherein the bonding wire connects the portion and the control unit.

[0092] (Appendix 12) 12. The semiconductor device of any one of claims 1 to 11, wherein the portion is obtained by laser welding.

[0093] (Appendix 13) 13. The semiconductor device according to any one of claims 1 to 12, wherein the semiconductor element has a reverse conducting insulated gate bipolar transistor.

[0094] (Appendix 14) 13. The semiconductor device according to any one of claims 1 to 12, wherein the semiconductor element includes silicon carbide as a semiconductor.

[0095] (Appendix 15) a main conversion circuit including the semiconductor device according to any one of Supplementary Notes 1 to 14, which converts input power and outputs the converted power; a drive circuit that outputs a drive signal to the semiconductor device; a control circuit that outputs a control signal to the drive circuit; A power conversion device comprising: [Explanation of symbols]

[0096] 4 semiconductor device, 7 part, 8 conductor, 8a part, 9,91,92,93 terminal, 60 insulator, 60d inside corner, 60f protrusion, 64a,64b semiconductor element, 63 wiring, 91a first part, 91b second part, 91c end face, 92c insertion part, 93a recess, 200 power conversion device, 201 main conversion circuit, 202 drive circuit, 203 control circuit, 641 control part, a distance, t thickness, Z direction.

Claims

1. a plate-shaped conductor having a first thickness; an insulator that encapsulates a portion of the conductor; a semiconductor element sealed in the insulator and electrically connected to the part; a terminal joined to the conductor outside the insulator; Equipped with a length along the conductor from a portion where the conductor and the terminal are joined toward the semiconductor element to the insulator is greater than the first thickness; The terminal is a first portion in contact with the conductor and joined to the conductor; a second portion connected to the first portion and bent relative to the first portion; and The terminal is a press-fit terminal having an insertion portion on the opposite side of the second portion from the first portion.

2. A plate-shaped conductor having a first thickness; an insulator that encapsulates a portion of the conductor; a semiconductor element sealed in the insulator and electrically connected to the part; a terminal joined to the conductor outside the insulator; Equipped with a length along the conductor from a portion where the conductor and the terminal are joined toward the semiconductor element to the insulator is greater than the first thickness; The terminal is a first portion in contact with the conductor and joined to the conductor; a second portion connected to the first portion and bent relative to the first portion; and the first portion and the second portion are connected to each other nearer to the semiconductor element than the portion; The first portion has an end surface on the conductor opposite the second portion.

3. the conductor has the first thickness along a first direction; The semiconductor device according to claim 2 , wherein the second portion sandwiches the conductor between itself and the insulator in the first direction.

4. the insulator has an inside corner; The semiconductor device according to claim 3 , wherein at the inside corner, the second portion sandwiches the conductor between itself and the insulator in the first direction.

5. The semiconductor device according to claim 4 , wherein the portion is aligned with the insulator along the first direction.

6. A plate-shaped conductor having a first thickness; an insulator that encapsulates a portion of the conductor; a semiconductor element sealed in the insulator and electrically connected to the part; a terminal joined to the conductor outside the insulator; Equipped with a length along the conductor from a portion where the conductor and the terminal are joined toward the semiconductor element to the insulator is greater than the first thickness; The insulator has a protrusion, The terminal has a recess that fits with the protrusion.

7. a bonding wire connecting the part to the semiconductor element; The semiconductor device according to claim 1 , further comprising:

8. the semiconductor device has a control unit, The semiconductor device according to claim 7 , wherein the bonding wire connects the part and the control unit.

9. The semiconductor device according to claim 1 , wherein the portion is obtained by laser welding.

10. 2. The semiconductor device according to claim 1, wherein said semiconductor element comprises a reverse conducting insulated gate bipolar transistor.

11. The semiconductor device according to claim 1 , wherein the semiconductor element includes silicon carbide as a semiconductor.

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

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