Semiconductor device

Abstract

To provide a semiconductor device in which variation of a position relative to a semiconductor chip, of a mounting part is suppressed.SOLUTION: In a power card that is a semiconductor device, a second component 92 comprises: an upper arm side semiconductor chip 30H; a mounting part (upper arm side second heat sink) 50H that comprises a first top surface 50a on which the upper arm side semiconductor chip is provided; a joint inner surface 72a that is integrally connected to the first top surface; a second joint part 72 that extends in a direction along the joint inner surface; and a first joint part 71 that is provided at a joint inner surface side of the second joint part. The second joint part comprises: a second extension part 75 that is arranged with the first joint part; and a first extension part 74 that is positioned between the second extension part and the mounting part, connects between the second extension part and the mounting part, and is easier to deform than the second extension part.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The disclosure described in this specification relates to a semiconductor device.

Background Art

[0002] Patent Document 1 describes a semiconductor device including a semiconductor chip, a first heat sink, and a second heat sink.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The second heat sink has a main body portion and an extended portion extending from the main body portion. The first heat sink has a joint portion connected to the extended portion. A semiconductor chip is provided on the main body portion.

[0005] If the joint portion excessively presses the extended portion, the main body portion may float upward toward the semiconductor chip side. There is a risk that the position of the main body portion (mounting portion) with respect to the semiconductor chip fluctuates.

[0006] Therefore, an object of the present disclosure is to provide a semiconductor device in which fluctuations in the position of the mounting portion with respect to the semiconductor chip are suppressed.

Means for Solving the Problems

[0007] A semiconductor device according to an aspect of the present disclosure is It constitutes the upper and lower arm circuits (9). An upper arm side semiconductor chip (30H) that constitutes the upper arm (9H) of the upper and lower arm circuits, A lower arm side semiconductor chip (30L) that constitutes the lower arm (9L) of the upper and lower arm circuits, A high potential power supply terminal (80P), a low potential power supply terminal (80N), and an output terminal (80S) as main terminals electrically connected to the electrodes of the upper arm side semiconductor chip and the lower arm side semiconductor chip, On the upper arm sideA mounting portion (50H) having a first upper surface (50a) on which a semiconductor chip is provided, A first relay portion (72) having a second upper surface (72a) connected to the first upper surface, A second relay portion (71) provided on the second upper surface side of the first relay portion, and having, The first relay portion has a parallel portion (75) aligned with the second relay portion, and a connecting portion (74) that is more deformable than the parallel portion connecting the parallel portion and the mounting portion, The forming material of the connecting portion includes a different material from the forming material of the parallel portion and, The main terminals project in the same direction with respect to the upper arm side semiconductor chip and the lower arm side semiconductor chip is included.

[0008] According to this, even if the second relay portion (71) excessively presses the first relay portion (72), the mounting portion (50H) is less likely to float upward toward the semiconductor chip (30H). Therefore, the variation in the position of the mounting portion (50H) with respect to the semiconductor chip (30H) is likely to be suppressed.

[0009] It should be noted that the reference numerals in the parentheses above only indicate the correspondence with the configurations described in the embodiments below, and do not limit the technical scope in any way.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Modes for Carrying Out the Invention

[0011] Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. In each mode, parts corresponding to those described in the preceding mode may be given the same reference numerals and redundant descriptions may be omitted. When only a part of the configuration is described in each mode, other modes described previously can be applied to other parts of the configuration.

[0012] In addition, not only combinations of parts that are clearly stated to be combinable in each embodiment, but also embodiments, embodiments and modified examples, and modified examples can be partially combined with each other as long as there is no problem with the combination, even if not explicitly stated.

[0013] (First Embodiment) First, based on FIG. 1, the schematic configuration of the vehicle drive system 1 will be described.

[0014] <Vehicle drive system> As shown in FIG. 1, the vehicle drive system 1 includes a DC power source 2, a motor generator 3, and a power conversion device 4.

[0015] The DC power source 2 is a DC voltage source composed of a rechargeable secondary battery. The secondary battery is, for example, a lithium-ion battery or a nickel-metal hydride battery. The motor generator 3 is a three-phase AC rotating electric machine. The motor generator 3 functions as a driving source for the vehicle, that is, as an electric motor. The motor generator 3 functions as a generator during regeneration. The power conversion device 4 performs power conversion between the DC power source 2 and the motor generator 3.

[0016] <Power conversion device> Next, based on FIG. 1, the circuit configuration of the power conversion device 4 will be described. The power conversion device 4 includes a smoothing capacitor 5 and an inverter 6.

[0017] The smoothing capacitor 5 mainly smooths the DC voltage supplied from the DC power source 2. One electrode of the smoothing capacitor 5 is connected to the positive electrode of the DC power source 2 and the inverter 6 via a P bus bar 7, respectively. The other electrode of the smoothing capacitor 5 is connected to the negative electrode of the DC power source 2 and the inverter 6 via an N bus bar 8, respectively. The DC power source 2, the smoothing capacitor 5, and the inverter 6 are connected in parallel between the P bus bar 7 and the N bus bar 8.

[0018] The inverter 6 is a DC-AC conversion circuit. The inverter 6 converts a DC current into an AC current by switching control by a control circuit mounted on a substrate 16. Then, the inverter 6 outputs the converted AC current to the motor generator 3. Thereby, the motor generator 3 is driven.

[0019] Also, when the vehicle is in regenerative braking, the inverter 6 converts the three-phase alternating current generated by the motor generator 3 upon receiving the rotational force from the wheels into a direct current according to the switching control by the control circuit, and outputs it to the P bus bar 7. In this way, the inverter 6 performs bidirectional power conversion between the DC power supply 2 and the motor generator 3.

[0020] The inverter 6 is configured to include upper and lower arm circuits 9 for three phases. The upper and lower arm circuits 9 are sometimes referred to as legs. The upper and lower arm circuits 9 have three-phase upper arms 9H and three-phase lower arms 9L. Each of the three-phase upper arms 9H is connected to the P bus bar 7. Each of the three-phase lower arms 9L is connected to the N bus bar 8. The inverter 6 has six arms.

[0021] Also, the upper arm 9H and the lower arm 9L are connected in series between the P bus bar 7 and the N bus bar 8. The connection point between the upper arm 9H and the lower arm 9L is connected to the corresponding phase winding 3a of the motor generator 3 via the output bus bar 10.

[0022] In this embodiment, an n-channel insulated gate bipolar transistor 11 is adopted as the switching element constituting each arm. Hereinafter, the n-channel insulated gate bipolar transistor 11 is denoted as IGBT11. A freewheeling diode 12 is reversely connected in parallel to each of the IGBT11s. Hereinafter, the freewheeling diode 12 is denoted as FWD12.

[0023] As shown in FIG. 1, in the upper arm 9H, the collector of the IGBT11 is connected to the P bus bar 7. In the lower arm 9L, the emitter of the IGBT11 is connected to the N bus bar 8. And the emitter of the IGBT11 in the upper arm 9H and the collector of the IGBT11 in the lower arm 9L are connected. The anode of the FWD12 is connected to the emitter of the corresponding IGBT11, and the cathode is connected to the collector.

[0024] The substrate 16 includes a control circuit and a drive circuit for a switching element that constitutes an inverter 6 or the like. The control circuit generates a drive command for operating the IGBT 11 and outputs it to the drive circuit. The drive circuit supplies a drive voltage to the gate of the IGBT 11 of the corresponding arm based on the drive command of the control circuit.

[0025] The control circuit generates a drive command based on a torque request input from a higher-level ECU and signals detected by various sensors.

[0026] The control circuit outputs, for example, a PWM signal as a drive command. The control circuit is configured to include, for example, a microcomputer. PWM is an abbreviation for Pulse Width Modulation. ECU is an abbreviation for Electronic Control Unit.

[0027] The drive circuit drives the corresponding IGBT 11 by applying a drive voltage, that is, turns it on and off. The drive circuit may be referred to as a driver.

[0028] Note that the power conversion device 4 may further include a converter as a power conversion circuit. The converter is a DC-DC conversion circuit that converts a DC voltage into a DC voltage of a different value. The converter is provided between the DC power supply 2 and the smoothing capacitor 5. The converter is configured to include, for example, a reactor and the upper and lower arm circuits 9 described above. The power conversion device 4 may include a filter capacitor for removing power supply noise from the DC power supply 2. The filter capacitor is provided between the DC power supply 2 and the converter.

[0029] <Mechanical Configuration of Power Card and Substrate> In the following, three directions that are orthogonal to each other are defined as the x direction, the y direction, and the z direction. Note that the description of "direction" is omitted in the drawings.

[0030] As shown in FIG. 1, the inverter 6 is composed of three upper and lower arms. One of the three upper and lower arms is provided on the power card 15 shown in FIG. 2. Note that the power card 15 corresponds to a semiconductor device.

[0031] Next, the mechanical configuration of the power card 15 will be described. For some of the elements constituting the power card 15, an "H" indicating the upper arm 9H side is added to the end of the reference numeral, and an "L" indicating the lower arm 9L side is added. For some other parts of the elements, for the sake of convenience, the same reference numeral is given to the upper arm 9H and the lower arm 9L.

[0032] The power card 15 constitutes an upper and lower arm circuit 9 for one phase. The power card 15 includes a coating resin 20, two semiconductor chips 30, two first heat sinks 40, two second heat sinks 50, two terminals 60, a joint part 70, a main terminal 80, solder 90, and a plurality of signal terminals 100.

[0033] The two semiconductor chips 30 are the upper arm side semiconductor chip 30H and the lower arm side semiconductor chip 30L. The two first heat sinks 40 are the upper arm side first heat sink 40H and the lower arm side first heat sink 40L. The two second heat sinks 50 are the upper arm side second heat sink 50H and the lower arm side second heat sink 50L. The two terminals 60 are the upper arm side terminal 60H and the lower arm side terminal 60L. The plurality of signal terminals 100 are the plurality of upper arm side signal terminals 100H and the plurality of lower arm side signal terminals 100L.

[0034] Note that the upper arm side second heat sink 50H corresponds to the mounting part. Hereinafter, the components of the power card 15 will be specifically shown as necessary.

[0035] As shown in FIG. 3, the joint part 70 has a first joint part 71, a second joint part 72, and a third joint part 73. The first joint part 71 is integrally connected to the lower arm side first heat sink 40L. The second joint part 72 is integrally connected to the upper arm side second heat sink 50H. The third joint part 73 is integrally connected to the lower arm side second heat sink 50L. Note that the first joint part 71 corresponds to the second relay part. The second joint part 72 corresponds to the first relay part.

[0036] The main terminal 80 has a positive terminal 80P, a negative terminal 80N, and an output terminal 80S. The positive terminal 80P is integrally connected to the upper arm side first heat sink 40H. The output terminal 80S is integrally connected to the lower arm side first heat sink 40L. The negative terminal 80N is electrically and mechanically connected to the third joint part 73 via the solder 90.

[0037] Note that the two first heat sinks 40, the joint part 70, the main terminal 80, and the plurality of signal terminals 100 described so far are configured as part of the lead frame during manufacturing.

[0038] The lead frame has tie bars integrally connected to the two first heat sinks 40, the joint part 70, the main terminal 80, and the plurality of signal terminals 100 in addition to those described above. The tie bars are removed after the molding of the coating resin 20. Thereby, each of the two first heat sinks 40, the joint part 70, the main terminal 80, and the plurality of signal terminals 100 is formed.

[0039] <Coating resin> As shown in FIGS. 2 and 4, the coating resin 20 seals a part of the components constituting the power card 15. The coating resin 20 seals two semiconductor chips 30, a part of the two first heat sinks 40, a part of the two second heat sinks 50, two terminals 60, the joint part 70, a part of the plurality of main terminals 80, and a part of the plurality of signal terminals 100 respectively. Note that in addition to the above-described components, the coating resin 20 also coats a plurality of wires 65 described later.

[0040] The remaining parts of the components constituting the power card 15 are exposed from the coating resin 20. Specifically, a part of the first back surface 40b, a part of the second back surface 50b, a part of the main terminal 80, and a part of each of the plurality of signal terminals 100 are exposed from the coating resin 20.

[0041] The coating resin 20 is made of, for example, an epoxy resin. The coating resin 20 is formed by, for example, a transfer molding method. As shown in FIGS. 2 and 4, the coating resin 20 has a substantially rectangular shape. The coating resin 20 has a first main surface 20a arranged in the y direction, a second main surface 20b on the back side of the first main surface 20a, and a plurality of connecting surfaces connecting the first main surface 20a and the second main surface 20b.

[0042] <Semiconductor chip> The semiconductor chip 30 is formed by forming vertical elements on a semiconductor substrate 31 made of, for example, silicon or a wide bandgap semiconductor having a wider bandgap than silicon. Examples of the wide bandgap semiconductor include silicon carbide, gallium nitride, gallium oxide, and diamond. The semiconductor substrate 31 has a flat shape with a small thickness in the y direction. The vertical elements are configured such that the main current flows in the y direction. The vertical elements in the present embodiment are the IGBT 11 and the FWD 12 that constitute one arm. Also, a MOSFET may be used as the vertical element.

[0043] As shown in FIG. 4, the semiconductor substrate 31 has a first substrate surface 31a located on the first main surface 20a side and a second substrate surface 31b located on the second main surface 20b side.

[0044] A collector electrode 31C is provided on the first substrate surface 31a of the semiconductor substrate 31. The collector electrode 31C is provided on substantially the entire surface of the first substrate surface 31a. Note that the collector electrode 31C also serves as the cathode electrode of the diode 12.

[0045] On the second substrate surface 31b of the semiconductor substrate 31, a gate electrode and an emitter electrode 31E are provided. The emitter electrode 31E is provided on a part of the second substrate surface 31b. The emitter electrode 31E also serves as the anode electrode of the diode 12.

[0046] In this embodiment, the collector electrode 31C, the emitter electrode 31E, and the semiconductor substrate 31 together are referred to as the semiconductor chip 30.

[0047] On the second substrate surface 31b, in addition to the gate electrode and the emitter electrode 31E described above, a plurality of pads 32P are provided. The plurality of pads 32P are provided on the second substrate surface 31b in a manner of being aligned with the emitter electrode 31E in the z direction. The pad 32P is an electrode for signals. The pad 32P is electrically separated from the emitter electrode 31E.

[0048] The pad 32P includes at least a pad 32P for the gate electrode and a pad 32P for the temperature-sensitive diode. The semiconductor chip 30 of this embodiment has five pads 32P. Specifically, it has a pad for the gate electrode, a Kelvin emitter for detecting the potential of the emitter electrode 31E, a pad for current sensing, a pad for the anode potential of the temperature-sensitive diode for detecting the temperature of the semiconductor chip 30, and a pad for the cathode potential as well. The five pads 32P are formed together on the end side in the z direction of the second substrate surface 31b and are formed so as to be spaced apart and aligned in the x direction.

[0049] The upper-arm-side semiconductor chip 30H and the lower-arm-side semiconductor chip 30L each have a similar configuration to each other. As shown in FIG. 4, the upper-arm-side semiconductor chip 30H and the lower-arm-side semiconductor chip 30L are arranged side by side with a gap in the x direction. The upper-arm-side semiconductor chip 30H and the lower-arm-side semiconductor chip 30L are arranged at substantially the same position as each other in the y direction.

[0050] <First heat sink> As shown in FIG. 4, the first heat sink 40 is disposed opposite to the collector electrode 31C of the semiconductor chip 30 in the y direction. The first heat sink 40 is electrically and mechanically connected to the collector electrode 31C via a solder 90. The first heat sink 40 has a first opposing surface 40a that is the surface on the semiconductor chip 30 side and a first back surface 40b on the back side of the first opposing surface 40a.

[0051] The first heat sink 40 dissipates the heat of the semiconductor chip 30 to the outside. As the first heat sink 40, for example, a metal plate made of Cu, a Cu alloy, or the like can be employed. Note that the first heat sink 40 may be provided with a plating film such as Ni or Au on its surface.

[0052] As shown in FIG. 4, the upper arm side first heat sink 40H and the lower arm side first heat sink 40L are substantially rectangular. The upper arm side first heat sink 40H and the lower arm side first heat sink 40L are arranged side by side with a gap in the x direction. The upper arm side first heat sink 40H and the lower arm side first heat sink 40L have substantially the same thickness and are arranged at substantially the same position in the y direction.

[0053] The space between the first opposing surface 40a of the upper arm side first heat sink 40H and the collector electrode 31C of the upper arm side semiconductor chip 30H is joined by a solder 90. The space between the first opposing surface 40a of the lower arm side first heat sink 40L and the collector electrode 31C of the lower arm side semiconductor chip 30L is joined by a solder 90.

[0054] Each of the upper arm side first heat sink 40H and the lower arm side first heat sink 40L encloses the corresponding semiconductor chip 30 in a plan view from the y direction.

[0055] In addition, the first back surfaces 40b of the upper arm side first heat sink 40H and the lower arm side first heat sink 40L are exposed from the coating resin 20. The first back surface 40b may be referred to as a heat dissipation surface. The first back surface 40b is substantially flush with the first main surface 20a of the coating resin 20. The first back surface 40b of the upper arm side first heat sink 40H and the first back surface 40b of the lower arm side first heat sink 40L are spaced apart in the x direction and arranged side by side.

[0056] <Second heat sink> As shown in FIG. 4, the second heat sink 50 is electrically and mechanically connected to the terminal 60 via the solder 90. The terminal 60 will be described in detail later.

[0057] The second heat sink 50 has a second facing surface 50a which is the surface on the semiconductor chip 30 side, and a second back surface 50b on the back side of the second facing surface 50a. The second heat sink 50 dissipates the heat of the semiconductor chip 30 to the outside. As the second heat sink 50, for example, a metal plate made of Cu, a Cu alloy, or the like can be adopted. Note that the second heat sink 50 may be provided with a plating film such as Ni or Au on its surface. Note that the second facing surface 50a corresponds to the first upper surface.

[0058] As shown in FIG. 4, the upper arm side second heat sink 50H and the lower arm side second heat sink 50L are substantially rectangular in shape. The upper arm side second heat sink 50H and the lower arm side second heat sink 50L are spaced apart in the x direction and arranged side by side.

[0059] The upper arm side second heat sink 50H and the lower arm side second heat sink 50L have substantially the same thickness as each other and are arranged at substantially the same position in the y direction. The second facing surface 50a of the upper arm side second heat sink 50H and the surface on the second facing surface 50a side of the upper arm side terminal 60H are joined by the solder 90. The second facing surface 50a of the lower arm side second heat sink 50L and the surface on the second facing surface 50a side of the lower arm side terminal 60L are joined by the solder 90.

[0060] The upper arm side second heat sink 50H and the lower arm side second heat sink 50L each enclose the corresponding semiconductor chip 30 in a plan view from the z direction.

[0061] As shown in FIG. 4, the second back surfaces 50b of the upper arm side second heat sink 50H and the lower arm side second heat sink 50L are exposed from the coating resin 20. The second back surface 50b may be referred to as a heat dissipation surface. The second back surface 50b is substantially flush with the second main surface 20b of the coating resin 20. The second back surface 50b of the upper arm side second heat sink 50H and the second back surface 50b of the lower arm side second heat sink 50L are spaced apart and arranged in the x direction.

[0062] <Terminal> The terminal 60 is interposed between the semiconductor chip 30 and the second heat sink 50 in the y direction, and electrically relays the emitter electrode 31E and the second heat sink 50. The terminal 60 is located in the middle of the electrical conduction and heat conduction paths between the emitter electrode 31E and the second heat sink 50. The terminal 60 is a columnar body formed using a metal material such as Cu or a Cu alloy. The terminal 60 may have a plating film on its surface. The terminal 60 may be referred to as a metal block body or an intermediate member.

[0063] As described above, the surface on the second facing surface 50a side of the upper arm side terminal 60H and the second facing surface 50a of the upper arm side second heat sink 50H are joined by solder 90. The surface of the upper arm side terminal 60H on the upper arm side semiconductor chip 30H side and the emitter electrode 31E provided on the second substrate surface 31b of the upper arm side semiconductor chip 30H are joined by solder 90.

[0064] Also, as described above, the surface of the lower arm side terminal 60L on the side of the second opposing surface 50a and the second opposing surface 50a of the lower arm side second heat sink 50L are joined by solder 90. The surface of the lower arm side terminal 60L on the side of the lower arm side semiconductor chip 30L and the emitter electrode 31E provided on the second substrate surface 31b of the lower arm side semiconductor chip 30L are joined by solder 90.

[0065] <Joint portion> As described above, the first joint portion 71 is integrally connected to the lower arm side first heat sink 40L. As shown in FIG. 5, the first joint portion 71 has a first extension portion 71a that extends in a manner spaced apart from the first opposing surface 40a in the z direction, and a second extension portion 71b that is connected to the first extension portion 71a and extends in a manner spaced apart from the lower arm side first heat sink 40L in the x direction.

[0066] As described above, the second joint portion 72 is integrally connected to the upper arm side second heat sink 50H. As shown in FIG. 5, the second joint portion 72 has a first extension portion 74 connected to one end of the upper arm side second heat sink 50H in the x direction, and a second extension portion 75 connected to the other end of the first extension portion 74 on the side spaced apart from the upper arm side second heat sink 50H in the x direction. Note that the first extension portion 74 corresponds to the connecting portion. The second extension portion 75 corresponds to the parallel portion.

[0067] In other words, the first extension portion 74 is located between the second extension portion 75 and the upper arm side second heat sink 50H in the x direction. In another way of putting it, the first extension portion 74 is located closer to the upper arm side second heat sink 50H than the second extension portion 75 in the x direction.

[0068] Each of the first extension portion 74 and the second extension portion 75 has a joint inner surface 72a and a joint outer surface 72b arranged in the z direction. As shown in FIG. 5, the joint inner surface 72a and the second opposing surface 50a are integrally connected. The joint outer surface 72b and the second back surface 50b are integrally connected. Note that the joint inner surface 72a corresponds to the second upper surface.

[0069] Speaking in detail about the inner joint surface 72a, the inner joint surface 72a of the first extension part 74 and the inner joint surface 72a of the second extension part 75 are flush in the x direction and the z direction.

[0070] Speaking in detail about the outer joint surface 72b, the outer joint surface 72b of the first extension part 74 is provided on the side of the second extension part 71b in the y direction with respect to the outer joint surface 72b of the second extension part 75.

[0071] The cross-sectional area cut by a plane along the direction orthogonal to the extending direction of the first extension part 74 is smaller than the cross-sectional area cut by a plane along the direction orthogonal to the extending direction of the second extension part 75.

[0072] Also, the second extension part 75 is arranged in a manner facing the second extension part 71b of the first joint part 71 in the z direction on the inner joint surface 72a side. Solder 90 is interposed between the second extension part 75 and the second extension part 71b. Thereby, the second extension part 75 and the second extension part 71b are electrically and mechanically connected.

[0073] The first joint part 71 and the second joint part 72 serve to electrically connect the emitter electrode 31E of the upper arm side semiconductor chip 30H and the collector electrode 31C of the lower arm side semiconductor chip 30L.

[0074] As described above, the third joint part 73 is integrally connected to the lower arm side second heat sink 50L. The third joint part 73 extends in a manner spaced apart from the upper arm side second heat sink 50H in the x direction.

[0075] The third joint part 73 and the negative terminal 80N are joined by solder 90. As shown in FIG. 4, it serves to electrically connect the emitter electrode 31E of the lower arm side semiconductor chip 30L and the negative terminal 80N.

[0076] <Main terminal> As described above, the main terminal 80 has a positive terminal 80P, a negative terminal 80N, and an output terminal 80S respectively.

[0077] The positive terminal 80P is electrically connected to the high potential side of the DC power supply 2 and the collector electrode 31C of the upper arm side semiconductor chip 30H. The positive terminal 80P may be referred to as a P terminal or a high potential power supply terminal.

[0078] The negative terminal 80N is electrically connected to the low potential side of the DC power supply 2 and the emitter electrode 31E of the lower arm side semiconductor chip 30L. The negative terminal 80N may be referred to as an N terminal or a low potential power supply terminal.

[0079] The output terminal 80S is connected to the connection point between the upper arm 9H and the lower arm 9L. More specifically, 80S is electrically connected to the emitter electrode 31E of the upper arm side semiconductor chip 30H and the collector electrode 31C of the lower arm side semiconductor chip 30L.

[0080] In addition to the emitter electrode 31E of the upper arm side semiconductor chip 30H and the collector electrode 31C of the lower arm side semiconductor chip 30L, the output terminal 80S is also electrically connected to the motor generator 3. The output terminal 80S may be referred to as an O terminal or an AC terminal.

[0081] The positive terminal 80P is formed by extending in the z direction from the end opposite to the side where the pad 32P of the upper arm side first heat sink 40H is provided. The output terminal 80S is formed by extending in the z direction from the end opposite to the side where the pad 32P of the lower arm side first heat sink 40L is provided. The negative terminal 80N is provided between the positive terminal 80P and the output terminal 80S in the x direction. The negative terminal 80N is joined to the third joint portion 73 via solder 90 or the like.

[0082] These positive terminal 80P, negative terminal 80N, and output terminal 80S are arranged in sequence with a separation in the x direction. A part of the positive terminal 80P, negative terminal 80N, and output terminal 80S is sealed by the coating resin 20. The remaining parts of the positive terminal 80P, negative terminal 80N, and output terminal 80S are exposed from the coating resin 20.

[0083] <Signal terminal> As described above, the plurality of signal terminals 100 include a plurality of upper arm side signal terminals 100H connected to the upper arm side semiconductor chip 30H and a plurality of lower arm side signal terminals 100L connected to the lower arm side semiconductor chip 30L. Each of the plurality of upper arm side signal terminals 100H and lower arm side signal terminals 100L is electrically and mechanically connected to the substrate 16.

[0084] As shown in FIGS. 2 and 3, the plurality of upper arm side signal terminals 100H are arranged side by side with a gap in the x direction. The plurality of upper arm side signal terminals 100H are electrically connected to pads 32P that are electrically connected to the upper arm side semiconductor chip 30H. Specifically, the upper arm side signal terminals 100H are electrically connected to pads 32P that are electrically connected to the upper arm side semiconductor chip 30H via upper arm side wires 65H.

[0085] Similarly, the plurality of lower arm side signal terminals 100L are arranged side by side with a gap in the x direction. The plurality of lower arm side signal terminals 100L are electrically connected to pads 32P that are electrically connected to the lower arm side semiconductor chip 30L. Specifically, the lower arm side signal terminals 100L are electrically connected to pads 32P that are electrically connected to the lower arm side semiconductor chip 30L via lower arm side wires 65L.

[0086] <Method for manufacturing a power card> The method for manufacturing the power card 15 will be described below.

[0087] First, a first jig 150 forming a housing is prepared. Next, a lead frame is mounted in the space of the first jig 150. Next, a plate-shaped solder 90 is mounted on the first opposing surface 40a of the lower arm side first heat sink 40L. The lower arm side semiconductor chip 30L is mounted on this plate-shaped solder 90. A plate-shaped solder 90 is mounted on this lower arm side semiconductor chip 30L. The lower arm side terminal 60L is mounted on this plate-shaped solder 90. A plate-shaped solder 90 is mounted on the lower arm side terminal 60L. A plate-shaped solder 90 is mounted on the surface of the first joint part 71 on the side of the first opposing surface 40a.

[0088] Similarly, a plate-shaped solder 90 is mounted on the first facing surface 40a of the upper arm side first heat sink 40H. The upper arm side semiconductor chip 30H is mounted on this plate-shaped solder 90. A plate-shaped solder 90 is mounted on this upper arm side semiconductor chip 30H. The upper arm side terminal 60H is mounted on this plate-shaped solder 90. A plate-shaped solder 90 is mounted on the upper arm side terminal 60H. Hereinafter, for the sake of simplicity of explanation, the components of the above-described power card 15 provided on the first jig 150 are collectively shown as a first component 91.

[0089] Next, the first component 91 is placed in a furnace (not shown) and heated. At this time, the plate-shaped solder 90 melts and becomes liquid. The liquid solder 90 is then cooled and solidified. The solidified solder 90 joins the components constituting the power card 15 together.

[0090] For example, the lower arm side first heat sink 40L and the lower arm side semiconductor chip 30L are joined by the solidified solder 90. The lower arm side semiconductor chip 30L and the lower arm side terminal 60L are joined by the solidified solder 90. The upper arm side first heat sink 40H and the upper arm side semiconductor chip 30H are joined by the solidified solder 90. The upper arm side semiconductor chip 30H and the upper arm side terminal 60H are joined by the solidified solder 90.

[0091] Also, each of the plate-shaped solder 90 provided on the lower arm side terminal 60L, the plate-shaped solder 90 provided on the first joint portion 71, and the plate-shaped solder 90 provided on the upper arm side terminal 60H solidifies into a hemispherical shape due to surface tension. Note that FIG. 6 shows the first component 91 in a state of being further cooled after being heated in a furnace.

[0092] Next, as shown in FIG. 7, a second jig 200 forming a housing is prepared. The second jig 200 has a bottom portion 210 and side portions 220 that stand up in the z direction in a manner surrounding the bottom portion 210 in an annular shape. Further, a protrusion 230 that extends in the extending direction of the side portion 220 is formed on the bottom portion 210 in a manner spaced apart from the bottom portion 210 in the z direction.

[0093] Mount the upper arm side second heat sink 50H and the lower arm side second heat sink 50L respectively in the space between the bottom 210 and the side portion 220. Mount the second joint portion 72 on the protrusion 230. There is a slight gap between the protrusion 230 and the second joint portion 72.

[0094] Next, as shown in FIG. 8, mount the first component 91 on the second facing surface 50a side of each of the upper arm side second heat sink 50H and the lower arm side second heat sink 50L. Hereinafter, for the sake of simplicity of explanation, the components constituting the power card 15 on which the first component 91 is mounted on the upper arm side second heat sink 50H and the lower arm side second heat sink 50L are collectively shown as the second component 92.

[0095] Next, put the second component 92 in the state provided on the second jig 200 into the furnace. As shown in FIG. 8, a spring body 300 that can expand and contract in the y direction is provided in the furnace. Put the second component 92 into the furnace so that the upper arm side first heat sink 40H and the lower arm side first heat sink 40L are in contact with the spring body 300 in the y direction.

[0096] At this time, a non-acting force in the y direction is applied from the spring body 300 to the second component 92. Heat the second component 92 in the furnace in this state.

[0097] When the second component 92 is heated, the solder 90 melts and becomes liquid. Then, as shown in FIG. 9, the thickness of the solder 90 in the y direction between the upper arm side terminal 60H and the upper arm side second heat sink 50H becomes thinner. The thickness of the solder 90 in the y direction between the first joint portion 71 and the second joint portion 72 becomes thinner. The thickness of the solder 90 in the y direction between the lower arm side terminal 60L and the lower arm side second heat sink 50L becomes thinner. Therefore, a load is likely to be applied to the second joint portion 72 from the first joint portion 71 in the y direction.

[0098] As shown in FIG. 8, there is a slight gap in the y direction between the second joint portion 72 and the protrusion 230. When the solder 90 melts with a biasing force in the y direction applied to the second component 92 by the spring body 300, a load is applied to the second joint portion 72 in the y direction from the first joint portion 71. As a result, the second joint portion 72 fluctuates so as to be pushed toward the protrusion 230 side.

[0099] When the second joint portion 72 fluctuates to the extent of contacting the protrusion 230, accordingly, the end of the upper arm side second heat sink 50H on the side separated from the protrusion 230 in the x direction floats upward from the bottom 210 toward the upper arm side terminal 60H. At that time, there is a possibility that the solder 90 provided between the upper arm side semiconductor chip 30H and the upper arm side terminal 60H spreads to the periphery of the region where the emitter electrode 31E of the upper arm side semiconductor chip 30H is provided.

[0100] A plurality of pads 32P are provided around the emitter electrode 31E of the upper arm side semiconductor chip 30H. There is a possibility that the solder 90 contacts the plurality of pads 32P and as a result, a short circuit occurs.

[0101] <Function and Effect> In the present embodiment, as described above, the cross-sectional area cut along a plane along the direction orthogonal to the extending direction of the first extension portion 74 is smaller than the cross-sectional area cut along a plane along the direction orthogonal to the extending direction of the second extension portion 75. Therefore, when a load in the y direction is applied to the second joint portion 72, the first extension portion 74 is more likely to deform actively than the second extension portion 75.

[0102] As a result, the fluctuation of the position of the upper arm side second heat sink 50H with respect to the upper arm side semiconductor chip 30H is likely to be suppressed. More specifically, the end of the upper arm side second heat sink 50H on the side separated from the protrusion 230 in the x direction is less likely to float upward from the bottom 210 toward the upper arm side terminal 60H. The upper arm side terminal 60H is less likely to be pressed against the upper arm side semiconductor chip 30H.

[0103] Accordingly, the solder 90 provided between the upper arm side semiconductor chip 30H and the upper arm side terminal 60H is less likely to spread to the periphery of the region where the emitter electrode 31E of the upper arm side semiconductor chip 30H is provided. The solder 90 is less likely to contact the plurality of pads 32P. Short circuit is more likely to be suppressed.

[0104] Also, as described above, the joint inner surface 72a of the first extension 74 and the joint outer surface 72b of the second extension 75 are flush in the x and z directions. The joint outer surface 72b of the first extension 74 is provided on the second extension 71b side in the y direction with respect to the joint outer surface 72b of the second extension 75.

[0105] Therefore, stress concentration is less likely to occur at the joints between the second extension 75 on the joint outer surface 72b side of the first extension 74 and the upper arm side second heat sink 50H on the joint outer surface 72b side of the first extension 74, respectively. The joints between the second extension 75 on the joint outer surface 72b side of the first extension 74 and the upper arm side second heat sink 50H on the joint outer surface 72b side of the first extension 74 are less likely to be damaged.

[0106] (First Modified Example) As shown in FIG. 10, the joint outer surface 72b of the first extension 74 and the joint outer surface 72b of the second extension 75 may be flush in the x and z directions. The joint inner surface 72a of the first extension 74 may be provided on the second extension 71b side in the y direction with respect to the joint inner surface 72a of the second extension 75 and the second opposing surface 50a of the upper arm side second heat sink 50H, respectively.

[0107] In that case, even if the solder 90 between the second extension 71b and the second extension 75 melts and spreads, the solder 90 is more likely to be caught in the space between the second extension 75 on the joint inner surface 72a side of the first extension 74 and the upper arm side second heat sink 50H.

[0108] (Second Modified Example) As shown in FIG. 11, the joint outer surface 72b of the first extension part 74 may be located closer to the second extension part 71b side in the y direction than the joint outer surface 72b of the second extension part 75. The joint inner surface 72a of the second extension part 75 may be located closer to the second extension part 71b side in the y direction than the joint inner surface 72a of the first extension part 74.

[0109] (Third Modification Example) As shown in FIG. 12, the cross-sectional area obtained by cutting along a plane perpendicular to the extending direction of the first extension part 74 may be equal to the cross-sectional area obtained by cutting along a plane perpendicular to the extending direction of the second extension part 75.

[0110] In that case, the material for forming the first extension part 74 may contain a different material from the material for forming the second extension part 75. For example, the member of the second extension part 75 may be Cu, and the member of the first extension part 74 may contain Al or the like that is more deformable than Cu. Note that all of the members of the first extension part 74 and the second extension part 75 may be different. It is sufficient that the first extension part 74 contains a different material from the second extension part 75.

[0111] Also, for the sake of simplicity in the following description, the cross-sectional area obtained by cutting along a plane perpendicular to the extending direction of the first extension part 74 is simply referred to as the cross-sectional area of the first extension part 74. The cross-sectional area obtained by cutting along a plane perpendicular to the extending direction of the second extension part 75 is simply referred to as the cross-sectional area of the second extension part 75.

[0112] (Fourth Modification Example) So far, the cases where the cross-sectional area of the first extension part 74 and the cross-sectional area of the second extension part 75 are different, and the case where the first extension part 74 contains a different material from the second extension part 75 have been described respectively. However, as shown in FIG. 13, the cross-sectional area of the first extension part 74 and the cross-sectional area of the second extension part 75 may be different, and furthermore, the first extension part 74 may contain a different material from the second extension part 75.

[0113] (Fifth Modification Example) As shown in Fig. 14, a hemispherical recess 76 may be formed in the second extension portion 75 so as to recess from the inner surface 72a of the joint to the outer surface 72b side of the joint. The radius of curvature of the recess 76 is smaller than the radius of curvature of the hemispherical solder 90 solidified in the first joint portion 71. Note that the recess 76 does not have to be limited to a hemispherical shape.

[0114] In that case, as shown in Fig. 15, when the second component 92 is heated in a furnace, the hemispherical solder 90 provided in the first joint portion 71 melts, and a part of the solder enters the recess 76. The first joint portion 71 and the second joint portion 72 are joined by the remaining solder 90. As shown in Fig. 16, the thickness of the solder 90 in the y direction between the first joint portion 71 and the second joint portion 72 becomes thinner.

[0115] Accordingly, the load applied from the first joint portion 71 to the second joint portion 72 tends to be reduced. Therefore, the end on the side spaced apart in the x direction from the protrusion 230 of the upper arm side second heat sink 50H is less likely to float upward from the bottom portion 210 toward the upper arm side terminal 60H.

[0116] (Sixth Modification Example) As shown in Fig. 17, the first component 91 may be provided on the first jig 150, and when heated in a furnace, a non-wetting lid-shaped third jig 400 may be applied to the solder 90 on the terminal 60 side of the first component 91.

[0117] By heating the first component 91 in a furnace with the third jig 400 applied to the first component 91, the solders 90 provided on the lower arm side terminal 60L, the upper arm side terminal 60H, and the second extension portion 71b of the first joint portion 71 are less likely to become hemispherical. The thickness of these solders 90 in the y direction is easily suppressed.

[0118] Therefore, when the first component 91 is provided on the second heat sink 50 as shown in Fig. 18, the gap in the y direction between the side portion 220 and the upper arm side first heat sink 40H and between the side portion 220 and the lower arm side first heat sink 40L is likely to be narrowed.

[0119] Therefore, when the solder 90 melts upon heating in the furnace, the amount of movement toward the upper-arm-side second heat sink 50H and the lower-arm-side second heat sink 50L of the first component 91 is likely to be suppressed. The solder 90 between the upper-arm-side second heat sink 50H and the upper-arm-side terminal 60H is less likely to spread. The solder 90 between the lower-arm-side second heat sink 50L and the lower-arm-side terminal 60L is less likely to spread.

Description of Reference Numerals

[0120] 30H... upper-arm-side semiconductor chip, 50a... second opposing surface, 50b... second back surface, 50H... upper-arm-side second heat sink, 60H... upper-arm-side terminal, 71... first joint portion, 72... second joint portion, 72a... inner surface of joint, 74... first extension portion, 75... second extension portion, 76... recess, 90... solder

Claims

Claim 1. A semiconductor device comprising an upper and lower arm circuit (9), an upper arm side semiconductor chip (30H) constituting the upper arm (9H) of the upper and lower arm circuit, a lower arm side semiconductor chip (30L) constituting the lower arm (9L) of the upper and lower arm circuit, a high potential power supply terminal (80P), a low potential power supply terminal (80N), and an output terminal (80S) as main terminals electrically connected to the electrodes of the upper arm side semiconductor chip and the lower arm side semiconductor chip, a mounting portion (50H) having a first upper surface (50a) on which the upper arm side semiconductor chip is provided, a first relay portion (72) having a second upper surface (72a) connected to the first upper surface, a second relay portion (71) provided on the second upper surface side of the first relay portion, wherein the first relay portion has a parallel portion (75) aligned with the second relay portion and a connecting portion (74) more deformable than the parallel portion connecting the parallel portion and the mounting portion, wherein the material forming the connecting portion contains a different material from the material forming the parallel portion, and the main terminals protrude in the same direction with respect to the upper arm side semiconductor chip and the lower arm side semiconductor chip. Claim 2. The semiconductor device according to claim 1, further comprising a plurality of signal terminals (100H, 100L) connected to signal electrodes in the upper arm side semiconductor chip and the lower arm side semiconductor chip, wherein the signal terminals protrude from the upper arm side semiconductor chip and the lower arm side semiconductor chip, respectively. Claim 3. An inverter (6) comprising the upper and lower arm circuits for three phases, and a substrate (16) comprising a control circuit for the upper arm side semiconductor chip and the lower arm side semiconductor chip, wherein the signal terminals are electrically connected to the substrate. Claim 4. The semiconductor device according to claim 2 or 3, wherein the signal terminals protrude in a direction opposite to the main terminals with respect to the upper arm side semiconductor chip and the lower arm side semiconductor chip. Claim 5. The semiconductor device according to any one of claims 2 to 4, further comprising a coating resin (20) that seals at least the upper arm side semiconductor chip and the lower arm side semiconductor chip in a state where a part of the main terminals and a part of the signal terminals are exposed.

6. The semiconductor device according to any one of claims 1 to 5, wherein the first relay portion and the second relay portion are provided between the upper arm side semiconductor chip and the lower arm side semiconductor chip in the arrangement direction of the upper arm side semiconductor chip and the lower arm side semiconductor chip.

7. A first lower arm side first heat sink (40L) integrally provided with the second relay portion, A lower arm side second heat sink (50L) disposed opposite to the first lower arm side first heat sink with the lower arm side semiconductor chip disposed between the first lower arm side first heat sink and the first lower arm side first heat sink, Further comprising a joint portion (73) integrally connected to the lower arm side second heat sink and to which the low potential power terminal is joined, The semiconductor device according to any one of claims 1 to 6, wherein the joint portion is provided between the upper arm side semiconductor chip and the lower arm side semiconductor chip in the arrangement direction of the upper arm side semiconductor chip and the lower arm side semiconductor chip.

8. The semiconductor device according to any one of claims 1 to 7, further comprising an upper arm side terminal (60H) provided on the upper arm side semiconductor chip, And a lower arm side terminal (60L) provided on the lower arm side semiconductor chip.

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