Power conversion device

Abstract

A power conversion device provided with a plurality of semiconductor modules and a wiring board connected to the semiconductor modules through through-holes, in which a semiconductor element has a plurality of signal terminals and a plurality of main terminals, the plurality of signal terminals and the plurality of main terminals protrude outward from the semiconductor modules in mutually opposite directions, and the plurality of signal terminals and the plurality of main terminals protrude outward from the semiconductor modules in mutually opposite directions. Each of the plurality of signal terminals has a bent portion at a position between the semiconductor module and the wiring substrate.

Description

Technical Field

[0001] This invention relates to an electric power conversion device. Background Technology

[0002] In addition to miniaturization and low-profile operation, power conversion devices also require easier manufacturing methods. Therefore, by employing a configuration that integrates the main circuit wiring within the printed circuit board, junctions can be eliminated, leading to miniaturization, low-profile operation, and increased productivity. Consequently, the reliability of junctions and other components is required in the configuration of power conversion devices.

[0003] As an example of a configuration to improve the reliability of a power conversion device, Patent Document 1 discloses the following configuration: In order to suppress excessive heat conduction from the semiconductor package to the control substrate, the semiconductor package has a control signal input lead whose shape is bent away from the semiconductor package, the control substrate is mounted on the top of the control signal input lead, and an air layer is provided between the semiconductor package and the control substrate.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-157485 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Inverters employing integrated main circuit wiring structures on printed circuit boards (PCBs) to further reduce miniaturization, lower backlighting, and improve productivity, which have been developed in accordance with previous requirements, suffer from reduced PCB rigidity due to the formation of through-holes for inserting semiconductor packages. If a semiconductor package with a sealing member having a larger coefficient of linear expansion than the PCB is inserted into the PCB's through-holes and connected to the PCB, warping occurs on the PCB side due to the difference in coefficients of linear expansion. Furthermore, excessive tensile stress is generated at the solder joints during assembling the PCB onto the water circuit, leading to reliability degradation during bonding.

[0009] Therefore, the object of the present invention is to provide a power conversion device that suppresses substrate warping during the bonding of semiconductor modules and printed circuit boards, reduces solder joint stress during water circuit assembly, and avoids an increase in main circuit inductance.

[0010] Methods for solving problems

[0011] A power conversion device includes: a plurality of semiconductor modules, each of which is sealed by a sealing member to a semiconductor element that converts direct current to alternating current; and a wiring substrate having a through hole and being connected to the semiconductor modules through the through hole, wherein the semiconductor element has a plurality of signal terminals and a plurality of main terminals, the wiring substrate has signal wiring connected to the signal terminals and main circuit wiring connected to the main terminals, the semiconductor modules control the conduction between the main terminals according to a control signal input via the signal terminals, the plurality of signal terminals and the plurality of main terminals protrude from the semiconductor modules in opposite directions to the outside, and the plurality of signal terminals each have a bend at a position between the semiconductor modules and the wiring substrate.

[0012] The effects of the invention

[0013] A power conversion device can be provided that can suppress substrate warping during bonding, reduce stress at the bonding joint during water circuit assembly, and prevent an increase in the inductance of the main circuit. Attached Figure Description

[0014] Figure 1 This is a circuit diagram of the power conversion device of the present invention.

[0015] Figure 2 These are perspective and top views of a power conversion device according to one embodiment of the present invention.

[0016] Figure 3 These are a top view and a cross-sectional view AA' of a one-phase power conversion device according to an embodiment of the present invention.

[0017] Figure 4 These are explanatory diagrams and perspective views illustrating the configuration of a semiconductor module according to one embodiment of the present invention.

[0018] Figure 5 This is the first variation.

[0019] Figure 6 This is the second variation.

[0020] Figure 7 This is the third variation.

[0021] Figure 8 yes Figure 7 Appearance drawing Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following description and drawings are examples for illustrating the present invention; appropriate omissions and simplifications have been made for clarity of explanation. The present invention may also be implemented in various other ways. Unless otherwise specified, the constituent elements may be singular or plural.

[0023] The positions, sizes, shapes, and extents of the constituent elements shown in the accompanying drawings are sometimes not representations of actual positions, sizes, shapes, or extents for ease of understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, and extents disclosed in the accompanying drawings.

[0024] (One embodiment and overall structure of the present invention)

[0025] ( Figure 1 )

[0026] The power conversion device 1 consists of multiple semiconductor devices that perform power conversion across the three phases: U, V, and W. Each semiconductor device includes an upper arm semiconductor element 4a and a lower arm semiconductor element 4b. The upper arm semiconductor element 4a and the lower arm semiconductor element 4b may be, for example, IGBTs (Insulated Gate Bipolar Transistors) or MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

[0027] The upper arm semiconductor element 4a and the lower arm semiconductor element 4b are provided with three terminals: a high-voltage side terminal for the main circuit (a collector terminal for IGBTs and a drain terminal for MOSFETs), a low-voltage side terminal for the main circuit (an emitter terminal for IGBTs and a source terminal for MOSFETs), and a signal terminal (gate terminal, etc.).

[0028] By forming multiple upper arm semiconductor elements 4a and lower arm semiconductor elements 4b and connecting them in parallel, the output current of the power conversion device 1 is increased. In the power conversion circuit of any phase of U, V, or W, the upper arm semiconductor elements 4a and lower arm semiconductor elements 4b connected in series are paired with capacitors 8. The capacitors 8 are, for example, film capacitors or electrolytic capacitors with large capacitance. By placing such capacitors 8 near the upper arm semiconductor elements 4a and lower arm semiconductor elements 4b, the wiring inductance of the positive wiring 2 and the negative wiring 3 is reduced. In addition, small ceramic capacitors 7 are connected in parallel on a phase-by-phase basis.

[0029] Each phase's output wiring 6 is connected to a load such as a motor (not shown). Additionally, the output wiring 6 is connected to multiple upper-arm semiconductor elements 4a and multiple lower-arm semiconductor elements 4b. The positive wiring 2 is connected to the positive terminal of a DC power source such as a battery (not shown), and the negative wiring 3 is connected to the negative terminal of a DC power source such as a battery. Thus, DC voltage is supplied to the semiconductor devices (power conversion circuits) of each phase.

[0030] The positive terminals of ceramic capacitor 7 and film capacitor 8 are connected to the high-voltage side terminal of the main circuit of upper arm semiconductor element 4a via positive wiring 2. Conversely, the negative terminals of ceramic capacitor 7 and film capacitor 8 are connected to the low-voltage side terminal of the main circuit of lower arm semiconductor element 4b via negative wiring 3.

[0031] The low-voltage side terminal of the main circuit of the upper arm semiconductor element 4a is connected to the high-voltage side terminal of the main circuit of the lower arm semiconductor element 4b through the output wiring 6 of each phase. The positive terminal wiring 2 is connected to the positive terminal of the capacitor 7 of other phases and the main circuit of the upper arm semiconductor element 4a of other phases through the high-voltage side terminal. The negative terminal wiring 3 is connected to the negative terminal of the capacitor 7 of other phases and the main circuit of the lower arm semiconductor element 4b of other phases through the low-voltage side terminal. In this way, a multi-phase circuit can be constructed.

[0032] The capacitor 8, such as a film capacitor 8 with large capacitance or a small ceramic capacitor 7, can reduce the wiring inductance of the positive wiring 2 and the negative wiring 3 by being arranged near the upper arm semiconductor element 4a and the lower arm semiconductor element 4b.

[0033] In the upper arm semiconductor element 4a and the lower arm semiconductor element 4b, signal terminals such as gate terminals are connected to a control circuit (not shown), which is turned on or off according to signals input from a higher-level control device such as a microcomputer, thereby outputting AC voltage to loads such as motors.

[0034] ( Figure 2 )

[0035] Figure 2 (a) is an overall perspective view of the power conversion device 1. Figure 2 (b) is an overall top view of the power conversion device 1. Multiple capacitors 8 are respectively connected to positive wiring 2 and negative wiring 3 provided on a wiring board 18, which serves as a control board. Positive wiring 2 and negative wiring 3 have DC input terminals 22, enabling DC power input from batteries, etc., to conduct through semiconductor modules 20 and 21.

[0036] When multiple capacitors 8 are of the type with large capacitance, such as film capacitors 8, the three-phase semiconductor devices (U-phase, V-phase, and W-phase) are arranged side by side along the arrangement direction on the side of the wiring substrate 18, thereby facilitating their fixation to the housing (not shown) of the power conversion device 1. This improves vibration resistance.

[0037] The upper arm semiconductor module 20, which has been molded and sealed with the semiconductor device having the upper arm semiconductor element 4a, and the lower arm semiconductor module 21, which has been molded and sealed with the semiconductor device having the lower arm semiconductor element 4b, extend in a row from the capacitor 8 to the output terminal 6a, respectively. This shortens the length of the positive electrode wiring 2, the negative electrode wiring 3, and the output wiring 6. As a result, the power conversion device 1 can be easily miniaturized. In addition, this facilitates the miniaturization of the externally mounted cooler and the ease of installation of the cooler.

[0038] ( Figure 3 )

[0039] Figure 3 (a) is a top view showing the state of a single-phase power conversion device 1 in which multiple semiconductor modules are connected to a substrate via wiring. Figure 3 (b) is Figure 3 The AA' cross-sectional view of (a) is an example of the configuration of the upper arm semiconductor module 20. Multiple semiconductor modules 20, 21 respectively seal the aforementioned semiconductor elements 4a, 4b that convert DC power into AC power through sealing members 17.

[0040] The wiring substrate 18 has through holes 23 and is connected to semiconductor modules 20 and 21 through the through holes 23. The wiring substrate 18 has signal wiring 15 connected to control terminals (signal terminals) 11 via solder or other terminal connection portions 14, and output wiring 6, which serves as main circuit wiring, connected to the main terminals 9 and 10 of the upper arm semiconductor element and the main terminals 12 and 13 of the lower arm semiconductor element via solder or other terminal connection portions 14. In the wiring substrate 18, the signal wiring 15 and the output wiring 6, which are connected to the upper arm semiconductor element 4a and the lower arm semiconductor element 4b via terminals, are the first layer of the substrate.

[0041] Semiconductor elements 4a and 4b have multiple signal terminals 11 and multiple main terminals. The semiconductor module 20 controls the switching of conduction between the main terminals according to the control signals input through the signal terminals 11.

[0042] The positive electrode wiring 2, negative electrode wiring 3, and output wiring 6 formed on the first layer of the wiring substrate 18 are electrically connected to another layer through interlayer connection portions 5 formed by vias or the like. By providing multiple interlayer connection portions 5 on the wiring substrate 18, the cross-sectional area of ​​the current flowing in the cross-sectional direction of the wiring substrate 18 can be increased, thereby reducing resistance and heat generation in the wiring. In addition, since the interlayer connection portions 5 improve the heat transfer in the cross-sectional direction of the wiring substrate 18, the rise in wiring temperature can be suppressed.

[0043] ( Figure 4 )

[0044] Figure 4 (a) is a top view illustrating the situation where signal terminals and main terminals protrude outward from semiconductor modules 20 and 21. Figure 4 (b) is Figure 4 The perspective view is shown in (a). Hereinafter, the terminals protruding from the semiconductor module will be described based on the upper arm semiconductor module 20. In the semiconductor module 20, a plurality of signal terminals 11 and a plurality of main terminals 9, 10 protrude from the semiconductor module 20 in mutually opposite directions. Furthermore, each of the plurality of signal terminals 11 has a bend 11b at a position between the semiconductor module 20 and the wiring substrate 18.

[0045] In the semiconductor module 20, the bent portion 11b has a protrusion 11c, and the protrusion 11c of the bent portion 11b of one signal terminal 11 and the protrusion 11c of the bent portion 11b of another signal terminal 11 face each other. In other words, in the semiconductor module 20, each bent portion 11b bends in a direction that approaches each other.

[0046] The reason for this configuration is that the rigidity of the wiring substrate 18 is reduced due to the through-hole 23. Specifically, since the coefficients of linear expansion of the connected semiconductor module 20 and the wiring substrate 18 are different, the shrinkage of the semiconductor module 20 is greater than that of the wiring substrate 18 during soldering, causing a stretching problem towards the center of the through-hole 23. The difference in shrinkage between the semiconductor module 20 and the wiring substrate 18 is mitigated by a small displacement of the bending portion 11b of the signal terminal 11. This reduces warping of the wiring substrate 18 during semiconductor module 20 bonding.

[0047] The bend 11b is not bent in the height direction, but in the direction in which the signal terminals 11 are arranged. Therefore, in the bonding of the semiconductor module 20 and the wiring substrate 18, the problem of the bend 11b hindering stacking can be solved by the arrangement of the heat dissipation member 16 (described later), which contributes to the reduction in the backlight and miniaturization of the power conversion device 1. Furthermore, by bending each bend 11b in a direction that brings them closer together, the surface distance of the root of the terminal in the signal terminals 11 can be ensured, thereby improving insulation performance.

[0048] Furthermore, by omitting the bend 11b from the main terminals 9 and 10 and instead placing it only on the side of the signal terminal 11, which does not carry a large current, the increased inductance or heat generated when placed on the side of the main terminals 9 and 10 carrying a large current can be avoided, thus improving the reliability of the connection. Additionally, the signal terminal 11 is easier to modify than the main terminals 9 and 10, which affect the handling of large currents, thereby facilitating design changes. Furthermore, by arranging the signal terminal 11 and the main terminals 9 and 10 on the upper surface of the semiconductor module 20, it is easy to connect to the wiring substrate 18, thus contributing to cost reduction. Moreover, the signal terminal 11 can be formed to a longer length without affecting performance, or the main terminals 9 and 10 can be shortened accordingly.

[0049] In the semiconductor module 20, by making the signal terminal 11 and the main terminals 9 and 10 protrude from opposite sides, magnetic coupling during switching operation can be minimized. Furthermore, by providing a bend 11b on the signal terminal 11 side, the influence of magnetism is minimized.

[0050] Furthermore, from the viewpoint of improving productivity, the length of the protrusion 11c protruding from the width of the signal terminal 11 is preferably greater than the width of the signal terminal 11. Additionally, as long as the insulation distance can be ensured, the bent portions 11b can be bent in the same direction or outwards towards each other.

[0051] (First variation)

[0052] ( Figure 5 )

[0053] Figure 5 (a) is an explanatory diagram showing the configuration of a semiconductor module according to a first modified embodiment of the present invention. Figure 5 (b) is Figure 5 A three-dimensional view of (a). Features of the first modified example are described based on the upper arm semiconductor module 20.

[0054] The bent portion 11b is bent in the thickness direction of the wiring substrate 18. Figures 1-4 In the embodiment described above, there is a step of assembling the bent portion 11b into the mold after it has been fabricated. Specifically, if it is Figure 4 The curved portion 11b described herein has an in-plane curved shape on the wiring substrate 18. When grinding the signal terminal 11, the curved shape needs to be formed, which poses a risk of interference between the curved shape and the mold of the sealing member 17.

[0055] However, if the bending portion 11b of the first modification is used, the bending portion 11b can be subsequently formed on the signal terminal 11 even after molding and sealing using the sealing member 17 in the semiconductor module 20. This improves the manufacturability of the power conversion device 1. However, in order to avoid contact with the heat dissipation member 16, which contacts the semiconductor module 20 (described later), the design of the arrangement of the heat dissipation member 16 needs to be considered.

[0056] (Second variation)

[0057] ( Figure 6 )

[0058] Figure 6 (a) is an explanatory diagram showing the configuration of a semiconductor module in a second modified example of one embodiment of the invention. Figure 6 (b) is Figure 6 (a) Overall perspective view. Features of the second modified example will be described based on the upper arm semiconductor module 20. In the semiconductor module 20, each bent portion 11b is L-shaped in the same direction and is within the size range of the semiconductor module 20 in the planar direction. Thus, with... Figure 4 and Figure 5 Compared to the U-shaped bending shape described above, the simplified L-shaped bending shape formed by the bending portion 11b improves productivity. Furthermore, it also addresses the issues of lower profile and miniaturization considering the placement of the heat dissipation component 16.

[0059] (3rd variation)

[0060] ( Figure 7 )

[0061] The features of the third modified example will be described based on the upper arm semiconductor module 20. Heat dissipation members 16 are provided on both sides of the semiconductor module 20 in the thickness direction and are in contact with the semiconductor module 20. For example, when the heat dissipation members 16 with internal water channels are assembled into the semiconductor module 20, they further apply stress to the joint. However, if a configuration is adopted that includes a signal terminal 11 with the bend 11b of the present invention, double-sided cooling of the semiconductor module 20 can be achieved while maintaining the reliability of the joint. Furthermore, although a double-sided cooling configuration is illustrated, single-sided cooling is also possible.

[0062] ( Figure 8 )

[0063] Figure 8 (a) is in Figure 7 A perspective view of the power conversion device 1 described above, showing heat dissipation components 16 installed on both sides. Figure 8 (b) is Figure 8(a) is an overall top view. Heat dissipation members 16 are arranged on the top and bottom of the wiring substrate 18. As a result, double-sided cooling of multiple semiconductor modules 20, 21 arranged on the wiring substrate 18 is possible, improving heat dissipation performance.

[0064] According to one embodiment of the present invention described above, the following effects are achieved.

[0065] (1) A power conversion device 1 includes: a plurality of semiconductor modules 20, 21, which are sealed by a sealing member 17 to semiconductor elements that convert DC power into AC power; and a wiring substrate 18 having a through hole 23 and connected to the semiconductor modules 20, 21 through the through hole 23. In the power conversion device 1, the semiconductor elements 4a, 4b have a plurality of signal terminals 11 and a plurality of main terminals. The wiring substrate 18 has signal wiring connected to the signal terminals 11 and main circuit wiring connected to the main terminals. The semiconductor modules 20, 21 control the conduction between the main terminals according to a control signal input via the signal terminals 11. The plurality of signal terminals 11 and the plurality of main terminals protrude from the semiconductor modules 20 in opposite directions to the outside. The plurality of signal terminals 11 each have a bend 11b at a position between the semiconductor modules 20 and the wiring substrate 18. Thus, a power conversion device 1 can be provided that can suppress warping of the wiring substrate 18 during assembly, reduce stress at the joint during assembly of the water channel 16, and prevent an increase in the inductance of the main circuit.

[0066] (2) In semiconductor modules 20 and 21, the bent portion 11b has a protrusion 11c, which is formed such that the protrusion 11c of the bent portion 11b of one signal terminal 11 and the protrusion 11c of the bent portion 11b of another signal terminal 11 face each other. As a result, the warping of the wiring substrate 18 during the bonding of the semiconductor module 20 can be reduced.

[0067] (3) In semiconductor modules 20 and 21, each bent portion 11b bends in a direction that approaches each other. As a result, the surface distance of the root of the signal terminal 11 can be ensured, thereby improving the insulation performance.

[0068] (4) The bending portion 11b is bent in the thickness direction of the wiring substrate 18. In this way, the manufacturability of the power conversion device 1 can be improved.

[0069] (5) In semiconductor modules 20 and 21, each bent portion 11b is L-shaped in the same direction and is within the size range of semiconductor modules 20 and 21 in the planar direction. This improves productivity. In addition, it also solves the problems of low backlighting and miniaturization considering the arrangement of heat dissipation component 16.

[0070] (6) Heat dissipation components 16 are provided on both sides of semiconductor modules 20 and 21 in the thickness direction. In this way, heat dissipation performance is improved.

[0071] Furthermore, the present invention is not limited to the embodiments described above, and various modifications or other configurations can be combined without departing from its spirit. Additionally, the present invention is not limited to the structure possessing all the configurations described in the above embodiments, but also includes structures in which a portion of the configuration has been omitted.

[0072] Explanation of symbols

[0073] 1 Power conversion device

[0074] 2 Positive wiring

[0075] 3 Negative wiring

[0076] 4 Semiconductor components

[0077] 4a upper arm semiconductor element

[0078] 4b lower arm semiconductor element

[0079] 5-layer connection section

[0080] 6 Output wiring

[0081] 6a output terminal

[0082] 7 Ceramic Capacitor

[0083] 8 capacitors

[0084] 9. Low-voltage side terminals for the main circuit of the upper arm semiconductor element

[0085] 10. High-voltage side terminals for the main circuit of the upper arm semiconductor element

[0086] 11 Control Terminals (Signal Terminals)

[0087] 11b Bend

[0088] 11c convex part

[0089] 12 Lower arm semiconductor element main circuit low-voltage side terminal

[0090] 13. High-voltage side terminal for the main circuit of the lower arm semiconductor element

[0091] 14-terminal connection section

[0092] 15 Signal cabling

[0093] 16 heat dissipation components

[0094] 16a heat dissipation surface

[0095] 17 Sealing components

[0096] 18-wire substrate

[0097] 20 Upper Arm Semiconductor Modules

[0098] 21 Lower Arm Semiconductor Module

[0099] 22 DC input terminals

[0100] 23 Through holes.

Claims

1. A power conversion device comprising: Multiple semiconductor modules, which use sealing members to seal semiconductor elements that convert direct current power to alternating current power; and A wiring substrate having through-holes and connected to the semiconductor module through the through-holes. The power conversion device is characterized in that... The semiconductor element has multiple signal terminals and multiple main terminals. The wiring substrate has signal wiring connected to the signal terminals and main circuit wiring connected to the main terminals. The semiconductor module controls the switching of conduction between the main terminals based on the control signal input via the signal terminal. The plurality of signal terminals and the plurality of main terminals protrude from the semiconductor module outward in opposite directions. The signal terminals are respectively positioned between the semiconductor module and the wiring substrate with bends.

2. The power conversion device as described in claim 1, characterized in that, In the semiconductor module, the bent portion has a protrusion. The protrusions of the bends of one signal terminal and the protrusions of the bends of the other signal terminal are formed facing each other.

3. The power conversion device as described in claim 2, characterized in that, In the semiconductor module, each of the curved portions bends toward each other in a direction that brings them closer together.

4. The power conversion device as described in claim 1, characterized in that, The bent portion bends in the thickness direction of the wiring substrate.

5. The power conversion device as described in claim 1, characterized in that, In the semiconductor module, each of the curved portions is an L-shape in the same direction and is within the size range of the semiconductor module in the planar direction.

6. The power conversion device as described in claim 1, characterized in that, Heat dissipation components are provided on both sides of the semiconductor module in the thickness direction.

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