Power semiconductor device

Abstract

Power semiconductor device (11) comprising: a circuit body having a pair of conductor components (32, 33) and a power semiconductor element (35, 36) embedded between the pair of conductor components (32, 33); a substrate (25) in which a through-hole (27) is formed; and a sealing material (13) sealing at least a section of both the circuit body and the substrate (25), wherein the circuit body is inserted into the through-hole (27) and has a first exposed surface (51) and a second exposed surface (52) that are exposed by the sealing material (13), and the substrate (25) in the through-hole (27) has a first projection (28) and a second projection (29) that project towards a center of the through-hole (27) and are connected to the circuit body.wherein the first projection (28) and the second projection (29) are formed at opposite positions in the through-hole (27) and the first projection (28) and / or the second projection (29) are terminals that transfer energy to the power semiconductor element (35, 36), and wherein the power semiconductor device (11) is characterized in that an AC wiring (64) which is installed in the substrate (25) and the second projection (29) are arranged such that they are opposite each other in the substrate (25).

Description

Technical field The present invention relates to a power semiconductor device. Background area For integrated motor / inverter power semiconductor devices, there is an increasing demand for size and height reduction in the manufacturing process. Therefore, continuous technical improvements have been implemented to create a highly efficient device while meeting these requirements. As background to the invention of the present application, the following patent literature 1 (PTL 1) discloses a technique for inserting a heat transfer distributor component (heat transfer conductor component) into a through-hole of a substrate and connecting an overhanging section of the distributor to a surface of the substrate, thereby ensuring that the thickness of a solder layer is as constant as possible in order to further stabilize the amount of a projection of an electrical conductor component from an opposite surface of the substrate. Furthermore, PTL 2, which forms the preamble, discloses a semiconductor device in which a power semiconductor is encapsulated in a housing. A separate control board is mounted on the ends of bent control leads that extend from the housing.This arrangement creates an air gap between the power semiconductor package and the control board, which acts as a thermal insulation layer, thus protecting the more heat-sensitive control board from overheating. PTL 3 discloses a semiconductor device in which a terminal electrode is connected to a conductor structure on a substrate using hard solder. To achieve a strong, high-temperature stable connection, the area wetted with hard solder on the conductor structure is larger than the base area of ​​the terminal electrode mounted on it. Finally, PTL 4 describes an encapsulated power semiconductor body in which a plate-shaped insulating element is arranged between the internal circuit board and an external cooling element. This insulating element has a special geometry in which its edge, embedded in the sealing material, is recessed relative to the central heat dissipation surface.This stepped design is intended to compensate for warping of the assembly due to shrinkage of the sealing material, thus ensuring permanently good adhesion of the cooling element. List of counterclaims Patent literature PTL 1: JP 5 445 562 B2PTL 2: JP 2013 - 157 485 APTL 3: DE 11 2017 002 424 T5PTL 4: DE 11 2020 006 116 T5 Summary of the invention Technical problem In the configuration of PTL 1, it is necessary to bypass internal wiring within the substrate and wire the surface, which leads to the problem of increased wiring complexity and thus higher inductance. In light of the foregoing, an object of the present invention is to provide a power semiconductor device that achieves both a reduction in wiring inductance and an improvement in the arrangement of the terminal housing and substrate. Solution to the problem To solve the problem, a power semiconductor device with the features of claim 1 is provided. An advantageous further development is described in the dependent claim. Advantageous effects of the invention According to the present invention, it is possible to create a power semiconductor device that achieves both a reduction in the inductance of the wiring and an improvement in the arrangement between a terminal housing and a substrate. Brief description of the drawings Fig. 1 is a perspective view of a complete inverter. Fig. 2 is a perspective overall view of the inverter after a cover body has been opened. Fig. 3 is a perspective sectional view of a cross-section taken along line AA of the inverter after the cover body has been opened. Fig. 4 is a cross-sectional view of Fig. 3. Fig. 5 is a development of a main circuit unit and a cooling water channel. Fig. 6 is a perspective view of the main circuit unit. Fig. 7 is a perspective view of the main circuit unit with a sealing resin omitted. Fig. 8 is a perspective sectional view of the main circuit unit according to an embodiment of the present invention with the sealing resin omitted. Fig. 9 is a perspective development of a terminal box according to an embodiment of the present invention.Figure 10 is a cross-sectional view taken along line CC in Figure 8. Figure 11 is a cross-sectional view taken along line BB in Figure 6. Figure 12 is a cross-sectional view taken along line BB in Figure 6, illustrating a switching transition current according to an embodiment of the present invention. Figure 13 is an electrical circuit diagram of the inverter. Description of the embodiments One embodiment of the present invention is described below with reference to the drawings. The following description and the drawings are examples used to describe the present invention and have been appropriately omitted and simplified for the sake of clarity. The present invention can be implemented in various other forms. Unless otherwise specified, each component can be singular or plural. For the purpose of facilitating understanding of the invention, the positions, sizes, shapes, areas, and the like of the components illustrated in the drawings need not represent actual positions, sizes, shapes, areas, and the like. Therefore, the present invention is not necessarily limited to the position, size, shape, area, and the like disclosed in the drawings. (One embodiment and overall configuration) Fig. 1 is a perspective view of a complete inverter. In an inverter 100, a cooling water channel and components are installed in a housing 1, and the installed components are sealed by a cover body 2. An AC connector 3 and a DC connector 4 protrude from the outside of the housing 1, and a signal connector 5 is also routed outwards. Fig. 2 is a perspective view of the inverter after the cover has been opened. The section line AA is used in Fig. 3 and Fig. 4. The housing of the inverter 100 contains a motor control substrate 6, a gate control substrate 7, a smoothing capacitor 8, an EMC filter 9, a cooling water channel 10, a main circuit unit 11, and a printed main circuit board 25 (see Fig. 6). The motor control substrate 6 is mounted on the upper side of Fig. 2, such that it covers the gate control substrate 7, the cooling water channel 10, and the main circuit unit 11. The signal connector 5 is mounted on the motor control substrate 6 and passes through the cover body 2 (Fig. 1) to the outside. Fig. 3 is a perspective sectional view of a cross-section taken along line AA after the inverter cover body has been opened, and Fig. 4 is a cross-sectional view taken along line AA from Fig. 2. A substrate connection pin 12 is mounted on the gate control substrate 7 and electrically connected to a substrate connection through-hole (see Fig. 6) of the main circuit unit 11 by means of a connecting material such as solder. Fig. 4 shows that the main circuit unit 11 is embedded between the cooling water channels 10. Fig. 5 is a development of the main circuit unit and the cooling water channel. The main circuit unit 11 is embedded and mounted between the cooling water channels 10. With this structure, the cooling water channel 10 cools the power semiconductor elements, which are mounted on several terminal housings in the main circuit unit 11, and the main circuit wiring of each component. Fig. 6 is a perspective view of the main circuit unit and Fig. 7 is a perspective view of the main circuit unit with a sealing resin omitted. In the main circuit unit 11, several terminal housings 26 are mounted on the printed main circuit board 25, all of which are encapsulated with a sealing resin 13. An AC connection component 20 and a DC connection component 21 are formed on the printed main circuit board 25 and are electrically connected to an AC bus rail and a DC bus rail (both not illustrated) by screw fastening. A substrate connection through-hole 22 and a capacitor connection through-hole 23 are provided so that a gate drive substrate and a smoothing capacitor (see Fig. 2 and Fig. 3) on the printed main circuit board 25 are electrically connected to each other by a connecting material such as solder. A mounting hole 24 is provided for connection to the cooling water channel, which is illustrated in Fig. 5. Fig. 8 is a perspective sectional view of the main circuit unit according to the embodiment of the present invention, in which the sealing resin is omitted. The section line CC is used in Fig. 10. A diode terminal housing 26D and an IGBT terminal housing 26T, which are the terminal housings 26, are inserted into through holes 27 formed in the printed main circuit board 25, and their connection terminals are electrically connected by a solder or the like to corresponding connection components (described later with reference to Fig. 10) of the printed main circuit board 25. A first conductor frame 32 and a second conductor frame 33 (common to the IGBT terminal housing 26T and the diode terminal housing 26D) of the terminal housing 26 embed electrodes on both sides of the IGBT or the diode element such that they are electrically connected. First connection components 30, provided on the first conductor frame 32, are electrically connected to a first projection and a second projection (described later) provided inside the through-hole 27. A second connection component 31, provided on the second conductor frame 33, is connected to surface wiring of the printed main circuit board 25 to form main circuit wiring. A buffer capacitor 40 is connected to positive electrode wiring and negative electrode wiring (described later) provided on the printed main circuit board 25 and supplies a transition current at the time of switching. Fig. 9 is a perspective unfolding of the connection housing according to the embodiment of the present invention. The diode terminal housing 26D and the IGBT terminal housing 26T from Fig. 9 are views obtained by unwinding the diode terminal housing 26D and the IGBT terminal housing 26T from Fig. 8 respectively, viewed from the back of the drawing. In the diode terminal housing 26D and the IGBT terminal housing 26T, a diode 36 and the IGBT 35, respectively, are embedded between the first conductor frame 32 and the second conductor frame 33. The first conductor frame 32 is provided at both ends with the first connection components 32, such that they are opposite each other. The second conductor frame 33 is provided with the second connection components 31, which have a shape that projects downwards in Fig. 9. On the first conductor frame 32 in the diode terminal housing 26D and on the second conductor frame 33 in the IGBT terminal housing 26T, base electrodes 34 are provided for connecting to a surface electrode of an element embedded between the first conductor frame 32 and the second conductor frame 33 while maintaining an insulation distance. Fig. 10 is a cross-sectional view taken along line CC in Fig. 8. The first conductor frame 32 and the second conductor frame 33, which are a conductor pair, and the IGBT 35 or the diode 36, which is a power semiconductor element embedded between them, form a circuit body. In the printed main circuit board 25, a first projection 28 and a second projection 20 are formed such that they project towards the center of the through-hole 27, into which each circuit body is inserted, and are formed at opposite positions in the through-hole 27. The second projection 29 is a terminal that is electrically connected to a wire 62 of a positive DC electrode and a wire 63 of a negative DC electrode. The first connection component 30 of the first conductor frame 32 and the first projection 28 and the second projection 29 in the through-hole 27 are electrically connected by a soldering compound or the like. Furthermore, the second connection component 31 of the second conductor frame 33 and a substrate surface wiring 50 are electrically connected by a soldering compound or the like. A signal contact pad (not illustrated) of the IGBT 35 is electrically connected to signal wiring formed on a surface of the printed main circuit board 25 by wire bonding or the like. Fig. 11 is a cross-sectional view taken along line BB in Fig. 6. In Fig. 10, after the connection between the terminal housing 26 and the printed main circuit board 25 is completed, the terminal housing 26 and the printed main circuit board 25 are completely covered and secured with the sealing resin 13. Here, each component connected by a solder is secured with the sealing resin 13 in such a way as to ensure tolerance with respect to fatigue failure, such as cracking. It should be noted that the circuit body can be arranged and secured on the substrate without the use of the sealing resin 13 by embedding it with components from above and below, or by screws or the like. This allows for a molding process in which the sealing resin 13 is omitted. After sealing with the sealing resin 13, a first exposed surface 51 and a second exposed surface 52, which are heat dissipation surfaces of the conductor frames 32 and 33 respectively, are formed by a surface of the sealing resin 13. Heat generated by the IGBT and the diode is dissipated from the first exposed surface 51 and the second exposed surface 52 through an insulating layer to the cooling water channel. With this configuration and connection, the inclination of the terminal housing 26 at the time of installation is improved, such that the positioning is improved, whereby the inclination at the time of injection molding of the circuit body and the entire substrate causes chip breakage and causes resin to cover the heat dissipation surface, and furthermore, a wiring length is shortened by the connection between the projection provided on the substrate and the conductor frame, such that inductance is reduced. Fig. 12 is a cross-sectional view taken along line BB in Fig. 6, illustrating a switching transition current according to the embodiment of the present invention. At the time of switching, a transition current 65 is supplied from the damping capacitor 40 (not illustrated in Fig. 12) such that the switching transition current 65 flows from the wiring of the positive DC electrode 62 on the printed main circuit board 25 through the second projection 29 to the wiring 63 of the negative DC electrode, which is connected to the other second projection, via the terminal housings 26D and 26T of the circuits of the upper and lower branch and an AC wiring 64. Here, as illustrated in Fig. 10, the second conductor frame 33, which forms a section of the circuit body, and the second projection 29, formed in the through-hole 27, are arranged in opposing positions, with the printed main circuit board 25 inserted between them. The AC wiring 64, embedded in the substrate, and the second projection 29 are arranged such that they face each other inside the substrate. These arrangements provide a structure in which a magnetic field is balanced by current paths in opposite directions, thus reducing the influence of noise. Fig. 13 is an electrical circuit diagram (an equivalent circuit) of the inverter. The equivalent circuit diagram illustrates one path of the transition current 65, supplied by the damping capacitor 40, at the time of switching. According to the embodiment of the present invention described above, the following processes and effects are achieved. (1) The main circuit unit 11, which is a power semiconductor device, comprises: the circuit body, which includes the first conductor frame 32 and the second conductor frame 33, which are a pair of conductor components, and the power semiconductor element (the IGBT 35, the diode 36) embedded between the first conductor frame 32 and the second conductor frame 33; the printed main circuit circuit board 25, in which the through-hole 27 is formed; and the sealing resin 13, which seals at least one section each of the circuit body and the printed main circuit circuit board 25. The circuit body is inserted into the through-hole 27 and has the first exposed surface 51 and the second exposed surface 52, which are exposed by the sealing resin 13.The printed main circuit board 25 has a first projection 28 and a second projection 29 in the through-hole 27, which protrude towards the center of the through-hole 27 and are connected to the circuit body. The first projection 28 and the second projection 29 are formed at opposite positions in the through-hole 27, and the first projection 28 and / or the second projection 29 is a terminal that transfers energy to the power semiconductor element. With this configuration, it is possible to create a power semiconductor device that achieves both a reduction in the inductance of the wiring and an improvement in the arrangement between a terminal housing and a substrate. (2) The second conductor frame 33 and the second projection 29 formed in the through-hole 27 are formed at opposite positions, with the printed main circuit board 25 inserted between them. This configuration reduces the influence of noise from a structure in which a magnetic field is counteracted by a reverse current path. (3) The AC wiring 64, which is installed in the printed main circuit board 25, and the second projection 29 are arranged such that they are opposite each other in the printed main circuit board 25. This configuration reduces the influence of noise. (4) The main circuit unit 11, which is a power semiconductor device, comprises the following: the circuit body, which includes the first conductor frame 32 and the second conductor frame 33, which are a pair of conductor components, and the power semiconductor element (the IGBT 35, the diode 36) embedded between the first conductor frame 32 and the second conductor frame 33; and the printed main circuit circuit board 25, in which the through-hole 27 is formed, and the sealing resin 13 need not be provided.Even in this case, the circuit body is inserted into the through-hole 27, and the printed main circuit board 25 has a first projection 28 and a second projection 29 in the through-hole 27, which project towards the center of the through-hole 27 and are connected to the circuit body, with the first projection 28 and the second projection 29 being formed at opposite positions in the through-hole 27, and the first projection 28 and / or the second projection 29 being a terminal that transfers energy to the power semiconductor element. In this way, it is possible to create a power semiconductor device that achieves an improvement in the arrangement without the need for a sealing resin.

[0048] List of reference numerals 1 Housing 2 Cover body 3 AC connector 4 DC connector 5 Signal connector 6 Motor control substrate 7 Gate drive substrate 8 Smoothing capacitor 9 EMC filter 10 Cooling water channel 11 Main circuit unit 12 Substrate connection pin 13 Sealing resin 20 AC connection component 21 DC connection component 22 Substrate connection through hole 23 Capacitor connection through hole 24 Mounting hole 25 Printed main circuit board 26 Terminal housing 26D Diode terminal housing 26T IGBT terminal housing 27 Through hole 28 First protrusion 29 Second protrusion 30 First connection component 31 Second connection component 32 First lead frame 33 Second lead frame 34 Base electrode 35 IGBT 36 Diode 40 Damping capacitor 41 IGBT element 42 Diode element 50 Substrate surface wiring 51 First exposed surface 52 Second exposed surface 61 Wiring inductance 62 Wiring of the positiveDC electrode 63 Wiring of the negative DC electrode 64 AC wiring 65 Switching current 100 Inverter

Claims

Power semiconductor device (11) comprising: a circuit body having a pair of conductor components (32, 33) and a power semiconductor element (35, 36) embedded between the pair of conductor components (32, 33); a substrate (25) in which a through-hole (27) is formed; and a sealing material (13) sealing at least a section of both the circuit body and the substrate (25), wherein the circuit body is inserted into the through-hole (27) and has a first exposed surface (51) and a second exposed surface (52) that are exposed by the sealing material (13), and the substrate (25) in the through-hole (27) has a first projection (28) and a second projection (29) that project towards a center of the through-hole (27) and are connected to the circuit body.wherein the first projection (28) and the second projection (29) are formed at opposite positions in the through-hole (27) and the first projection (28) and / or the second projection (29) are terminals that transfer energy to the power semiconductor element (35, 36), and wherein the power semiconductor device (11) is characterized in that an AC wiring (64) which is installed in the substrate (25) and the second projection (29) are arranged such that they are opposite each other in the substrate (25). Power semiconductor device (11) according to claim 1, wherein the conductor component (33) and the second projection (29) formed in the through-hole (27) are formed at positions opposite each other, with the substrate (25) inserted between them.

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