POWER SEMUBLER DEVICE

Abstract

Power semiconductor device (100) comprising the following: a power semiconductor element (204L, 204U) having a low-potential electrode (303), a high-potential electrode (304) and a sensing electrode (301, 302); a high-potential conductor that is electrically connected to the high-potential electrode (304); a low-potential conductor that is electrically connected to the low-potential electrode (303); a detection wiring system that is electrically connected to the detection electrode (301, 302); and a first metal section (106) facing the low-potential conductor or the low-potential conductor beyond the detection wiring, wherein seen from an arrangement direction of the detection wiring and the first metal section (106) the detection wiring has an adjacent section that faces either the high-potential conductor or the low-potential conductor, the first metal section (106) forms a recess (406) in a part that overlaps with the facing section and a depth of the recess (406) is formed such that a distance between a bottom of the recess (406) and the detection wiring is greater than a distance between the detection wiring and the high-potential conductor or the low-potential conductor, wherein the detection wiring includes a detection wiring (202L, 202U) of a negative electrode and a detection wiring (203L, 203U) of a positive electrode, which is different from the detection wiring of the negative electrode (202L, 202U), and seen from an arrangement direction of the detection wiring and the first metal section (106) the detection wiring (202L, 202U) of the negative electrode is provided such that it overlaps with the recess (406), and the detection wiring (203L, 203U) of the positive electrode is provided in such a way that it does not overlap with the recess (406).

Description

Technical field

[0001] The present invention relates to a power semiconductor device, in particular to a power semiconductor device that controls a vehicle-internal drive motor. Technical background

[0002] In recent years, it has been necessary for a power conversion device equipped with a power semiconductor device to have short-circuit protection and high heat dissipation. PTL 1 discloses a means of ensuring a protective process by magnetic coupling between a main circuit terminal and a control terminal, even when di / dt is large during the rise or fall of a short-circuit current. PTL 2 discloses a structure in which heat dissipation properties are improved by covering a power semiconductor element with an external metal.

[0003] However, it is necessary to further improve the reliability of the power semiconductor device when short-circuit protection is activated.

[0004] Furthermore, PTL 2 describes a semiconductor device. This device includes a metal block having a first and a second main surface, with a recess defined on the first main surface. It also includes a semiconductor chip that is accommodated within the recess of the metal block and mounted on the metal block. Furthermore, a first terminal electrically connected to the semiconductor chip and a second terminal electrically connected to the metal block are provided.

[0005] PTL 3 describes a semiconductor device constructed such that a recessed section housing a heat-generating element is formed on a heat sink, a bottom electrode is formed on the heat-generating element, a top peripheral electrode is formed on the heat-generating element, a metallic ring-shaped element is formed on the heat sink and the top peripheral electrode is formed on the heat-generating element, and the recessed section of the heat sink and the bottom electrode on the heat-generating element are soldered together, while the heat sink, the top peripheral electrode, and the ring-shaped element on the heat-generating element are soldered together. (Reference list) Patent literature PTL 1: JP 2014 - 229 642 A PTL 2: DE 10 2005 050330 A1 PTL 3: JP 2002 - 329 804 A PTL 2: JP 2016 - 36 194 A Summary of the invention: Technical problem

[0006] It is an object of the present invention to suppress an overvoltage during the occurrence of an overcurrent without impairing the heat dissipation properties of a power semiconductor device and to improve reliability. Solution to the problem

[0007] A power semiconductor device according to the present invention is described in the independent claim. Preferred technical developments are shown in the dependent claims.

[0008] Thus, a main circuit and a control terminal in the power semiconductor are magnetically coupled by providing a recess in a heat dissipation base plate, which is an external metal that causes magnetic coupling to be suppressed, and the voltage of the control terminal is slowly switched off when the short-circuit protection is activated, thereby suppressing an overvoltage that causes deterioration of the semiconductor element. Advantageous effects of the invention

[0009] According to the present invention, an overvoltage during overcurrent generation can be suppressed without impairing the heat dissipation properties of a power semiconductor module. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is an external front view of a power semiconductor device 100 according to the present embodiment. [ Fig. 2] Fig. 2 is an external front view of the power semiconductor device 100 according to the present embodiment in a direction opposite to that of Fig. 1 seen. [ Fig. 3] Fig. Figure 3 is an internal structure view of the power semiconductor device 100, which is located in Fig. Figure 1 shows a casting material 405 that has been removed. [ Fig. 4] Fig. Figure 4 is an internal structure view of the power semiconductor device 100, which is located in Fig. Figure 3 shows the low-potential conductors 201U and 201L being removed. [ Fig. 5] Fig. 5 is a cross-sectional view of the power semiconductor device 100, where a cross-section A-A' is located in Fig. 1 is shown, viewed from the direction of the arrow. [ Fig. 6] Fig. Figure 6 is a circuit diagram showing a configuration of a control circuit corresponding to the power semiconductor device 100 according to the present embodiment. [ Fig. 7] Fig. 7 is an operating waveform on one side of a lower branch of the inverter circuit when the inverter circuit's short-circuit protection is activated. [ Fig. 8] Fig. Figure 8 is an external front view showing a power semiconductor device 200 according to a further embodiment. [ Fig. 9] Fig. Figure 9 is a cross-sectional view of the power semiconductor device 200, which is located in Fig. Figure 8 shows a cross-section viewed along the dashed line from the direction of the arrow. Description of the embodiments

[0010] Embodiments of the power semiconductor device according to the present invention are described below with reference to the drawings. In each figure, identical elements are given the same reference numerals, and redundant descriptions are omitted. The present invention is not limited to the following embodiments and includes various modifications and applications of the technical concept of the present invention.

[0011] Fig. Figure 1 is an external front view of the power semiconductor device 100 according to the present embodiment.

[0012] Fig. 2 is an external front view of the power semiconductor device 100 according to the present embodiment in a direction opposite to that of Fig. 1 seen. Fig. Figure 3 is an internal structure view of the power semiconductor device 100, which is located in Fig. Figure 1 shows a casting material 405 that has been removed. Fig. Figure 4 is an internal structure view of the power semiconductor device 100, which is located in Fig. Figure 3 shows the low-potential conductors 201U and 201L being removed. Fig. 5 is a cross-sectional view of the power semiconductor device 100, where the cross-section A-A' is shown in Fig. 1 is shown, viewed from the direction of the arrow. Fig. Figure 6 is a circuit diagram showing the configuration of a control circuit corresponding to the power semiconductor device 100 according to the present embodiment.

[0013] As a power semiconductor element 204, which is in Fig. As shown in Figure 4, a MOSFET or an IGBT, for example, can be used. The power semiconductor element 204 comprises a power semiconductor element 204U on the upper branch side, which forms an upper branch of an inverter circuit, and a power semiconductor element 204L on the lower branch side, which forms a lower branch of the inverter circuit.

[0014] As in Fig. 4 and Fig. As shown in Figure 6, an AC output terminal 103 is connected to a high-potential conductor 205L, which is connected to an emitter electrode side of the power semiconductor element 204L on the lower branch side. An intermediate electrode 207 connects the low-potential conductor 201U and the high-potential conductor 205L, which are located in Fig. 3 and Fig. Figure 6 shows an intermediate electrode 206 connecting the low-potential conductor 201L and the high-potential conductor 205L, which are located in Fig. 3 and Fig. 6 are shown.

[0015] The high-potential conductor 205U forms a conductor of a high-potential side on the side of the upper branch of the inverter circuit of Fig. 6.

[0016] The power semiconductor elements 204U and 204L, which are in Fig. Figure 4 shows each sensing electrode 301 of a positive electrode, a sensing electrode 302 of a negative electrode, a low-potential electrode 303, and a high-potential electrode 304 (rear side of the power semiconductor element 204L). If these electrodes are IGBTs, sensing electrode 301 corresponds to the positive electrode of a gate electrode, sensing electrode 302 corresponds to the negative electrode of a Kelvin emitter electrode, the low-potential electrode 303 corresponds to an emitter electrode, and the high-potential electrode 304 corresponds to a collector electrode.If these electrodes are MOSFETs, the sensing electrode 301 corresponds to the positive electrode of a gate electrode, the sensing electrode 302 corresponds to the negative electrode of a Kelvin source electrode, the low-potential electrode 303 corresponds to a source electrode, and the high-potential electrode 304 corresponds to a drain electrode.

[0017] A detection wiring 203L of a positive electrode is mounted on an insulating layer 401. The detection wiring 203L of the positive electrode is connected to a detection terminal 104L of a positive electrode by means of a solder material. The detection electrode 301 of the positive electrode is electrically connected to the detection wiring 203L of the positive electrode by means of wire bonds 305.

[0018] A detection wiring 202L of a negative electrode is mounted on the insulation layer 401. The detection wiring 202L of the negative electrode is connected to a detection terminal 105L of a negative electrode by means of solder. The detection electrode 302 of the negative electrode is electrically connected to the detection wiring 202L of the negative electrode by means of wire bonds 306.

[0019] Accordingly, the detection wiring 203U of the positive electrode is mounted on the insulation layer 401. The detection wiring 203U of the positive electrode is connected to a detection terminal 104U of a positive electrode by means of a solder material.

[0020] A detection wiring 202U of a negative electrode is mounted on the insulation layer 401. The detection wiring 202U of the negative electrode is connected to a detection terminal 105U of a negative electrode by means of a solder material.

[0021] As in Fig. As shown in Figure 5, the low-potential electrode 303 is electrically connected to a spacer 403 by means of a solder material 402. The spacer 403 is electrically connected to the low-potential conductor 201L by means of the solder material 402. The low-potential conductor 201L is connected to the low-potential terminal 102, which is located in Fig. As shown in section 4, they are electrically connected using a solder material.

[0022] As in Fig. As shown in Figure 5, the high-potential electrode 304 is electrically connected to the high-potential conductor 205L, which is mounted on the insulating layer 401. The high-potential conductor 205L is electrically connected to a high-potential terminal 101 by means of a solder material.

[0023] A soldered conductor pattern 404 is mounted on the insulating layer 401. A first metal section 106 is connected to the soldered conductor pattern 404 by means of the solder material 402. For example, aluminum or copper is used for the first metal section 106.

[0024] The first metal section 106 has a recess 406 formed in a portion facing the low-potential conductor 201L beyond the sensing wiring 202L of the negative electrode. The sensing wiring 203L of the positive electrode is located closer to the power semiconductor element 204L than the recess 406.

[0025] The depth of the recess 406 is such that the distance between the bottom of the recess 406 and the detection wiring 202L of the negative electrode is greater than the distance between the detection wiring 202L of the negative electrode and the low-potential conductor 201. This enables magnetic coupling between the low-potential conductor 201L and the detection wiring 202L.

[0026] If the soldered conductor pattern 404 runs to the lower section of the sensing wiring 202L of the negative electrode, the magnetic coupling between the sensing wiring 202L of the negative electrode and the low-potential conductor 201 is weakened.

[0027] It is desirable that the recess 406 be configured such that the soldered conductor pattern 404 and the solder material 402, which are conductors, do not overlap when viewed from the orientation of the sensing wiring 202L of the negative electrode and the recess 406. Thus, the sensing wiring 202L of the negative electrode and the low-potential conductor 201L can be strongly magnetically coupled.

[0028] As in Fig. As shown in Figure 6, the sensing wire 203L of the positive electrode is connected to a gate resistor 502L. The gate resistor 502 and the sensing wire 202L of the negative electrode are connected to a signal source 501L.

[0029] The high-potential terminal 101 is connected to a smoothing capacitor 504 and one side of a positive electrode of a DC voltage source 505. The low-potential terminal 102 is connected to the smoothing capacitor 504 and one side of a negative electrode of the DC voltage source 505. A load is connected to the AC output terminal 103.

[0030] Fig. 7 is an operating waveform on one side of a lower branch of the inverter circuit when the inverter circuit's short-circuit protection is activated. Fig. Figure 7 shows a case where a MOSFET is used as the 204L power semiconductor element. The same waveform is obtained in the case of the IGBT and in the case of the upper branch.

[0031] If a short circuit occurs in the upper / lower branch due to a malfunction or fault at t1, a current flows from the smoothing capacitor 504, which is located in Fig. Figure 6 shows a significant increase in the source current Is. This is called the short-circuit current.

[0032] If a short-circuit current is detected at t2, a signal from signal source 501L is generated. Fig. When 6 is output, it is switched off.

[0033] Depending on di / dt, as the source current Is falls from t2 to t3 after the signal output by signal source 501L has been switched off, a voltage is induced in the sensing wiring 202L of the negative electrode. This induced voltage slows the fall of the gate / source voltage Vgs and suppresses a sharp decrease in the short-circuit current. The slowly decreasing short-circuit current suppresses a surge voltage Vds generated between the drain and source, thus preventing degradation of the semiconductor element due to the surge voltage.

[0034] Fig. Figure 8 is an external front view showing a power semiconductor device 200 according to a further embodiment. Fig. Figure 9 is a cross-sectional view of the power semiconductor device 200, which is located in Fig. Figure 8 shows a cross-section viewed along the dashed line from the direction of the arrow. In the embodiment shown in Fig. 8 and Fig. As shown in Figure 9, the components that have the same reference symbols as the components shown in Figure 9 have the same reference symbols. Fig. 1 to Fig. The functions described in section 7 are the same as those described in [reference to relevant section]. Fig. 1 to Fig. 7 are described.

[0035] According to the structure that is in Fig. As shown in Figure 5, the first metal section 106 has the recess 406, which is formed in a part facing the low-potential conductor 201 beyond the detection wiring 202L of the negative electrode and the detection wiring 202U of the negative electrode.

[0036] In the present embodiment, a second metal section 107 is arranged in a position facing the first metal section 106 via the power semiconductor elements 204U and 204L.

[0037] The second metal section 107 is connected to the soldered conductor pattern 404 by means of the solder material 402. For example, aluminum or copper is used for the second metal section 107.

[0038] The second metal section 107 has a recess 407, which is formed in a part facing the detection wires 202L and 202U of the negative electrode via the low-potential conductors 201L and 201U. The detection wires 203L and 203U of the positive electrode must be arranged inside the recess 407.

[0039] The depth of the recess 407 is such that the distance between the bottom of the recess 407 and the low-potential conductor 201L or 201U is greater than the distance between the detection wiring 202L or 202U of the negative electrode and the low-potential conductor 201L or 201U. The recess 407 magnetically couples the detection wiring 202 of the negative electrode and the low-potential conductor 201.

[0040] As in Fig. As shown in Figure 6, the sensing wires 203U and 203L of a positive electrode are electrically connected to a gate resistor 502U, and the gate resistor 502U and the sensing wires 202L or 202U of the negative electrode are connected to a signal source 501U. The recesses 406 and 407 form a magnetic coupling structure in the low-potential conductor 201 and in the sensing wiring 202.

[0041] According to the present embodiment, in addition to the effects which are identical to those of the embodiment described in Fig. 1 to Fig. As shown in Figure 7, it is possible to further improve the heat dissipation properties and to suppress overvoltage during the occurrence of an overcurrent.

[0042] Furthermore, the width of the recess 406 of the first metal section 106 or the width of the recess 407 of the second metal section 107, as in Fig. 1 to Fig.As shown in Figure 9, it is formed such that it is larger than the width of the detection wiring 202. This further improves the effectiveness of suppressing the overvoltage during the occurrence of the overcurrent. Reference symbol list 100 power semiconductor device 101 high-potential side connection 102 low-potential connection 103 AC output connector 104L Detection connection of a positive electrode 104U Detection terminal of a positive electrode 105L Detection connection of a negative electrode 105U Detection terminal of a negative electrode 106 first metal section 107 second metal section 200 power semiconductor device 201L low-potential conductor 201U low-potential conductor 202L Detection wiring of a negative electrode 202U Detection wiring of a negative electrode 203L Detection wiring of a positive electrode 203U Detection wiring of a positive electrode 204L power semiconductor element on the side of a lower branch 204U power semiconductor element on the side of an upper branch 205L high-potential conductor 205U high-potential side conductor 206 Intermediate electrode 207 Intermediate electrode 301 Detection electrode of the positive electrode 302 Detection electrode of the negative electrode 303 low-potential side electrode 304 high-potential side electrode 305 wire bonding 306 wire bonds 401 Insulation layer 402 Solder material 403 spacers 404 Soldered conductor pattern 405 Casting material 406 recess 407 Recess 501L Signal source 502L Gate resistor 504 Smoothing capacitor 505 DC voltage source

Claims

[1] Power semiconductor device (100) comprising the following: a power semiconductor element (204L, 204U) having a low-potential electrode (303), a high-potential electrode (304) and a sensing electrode (301, 302); a high-potential conductor that is electrically connected to the high-potential electrode (304); a low-potential conductor that is electrically connected to the low-potential electrode (303); a detection wiring system that is electrically connected to the detection electrode (301, 302); and a first metal section (106) facing the low-potential conductor or the low-potential conductor beyond the detection wiring, wherein seen from an arrangement direction of the detection wiring and the first metal section (106) the detection wiring has an adjacent section that faces either the high-potential conductor or the low-potential conductor, the first metal section (106) forms a recess (406) in a part that overlaps with the facing section and a depth of the recess (406) is formed such that a distance between a bottom of the recess (406) and the detection wiring is greater than a distance between the detection wiring and the high-potential conductor or the low-potential conductor, wherein the detection wiring includes a detection wiring (202L, 202U) of a negative electrode and a detection wiring (203L, 203U) of a positive electrode, which is different from the detection wiring of the negative electrode (202L, 202U), and seen from an arrangement direction of the detection wiring and the first metal section (106) the detection wiring (202L, 202U) of the negative electrode is provided such that it overlaps with the recess (406), and the detection wiring (203L, 203U) of the positive electrode is provided in such a way that it does not overlap with the recess (406). [2] Power semiconductor device (100) according to claim 1, wherein a width of the recess (406) of the first metal section (106) is formed such that it is larger than a width of the detection wiring. [3] Power semiconductor device (100) according to claim 1 or 2, comprising the following: a second metal section (107) which faces the first metal section (106) beyond the detection wiring and the low-potential electrode (303). [4] Power semiconductor device (100) according to claim 3, wherein the second metal section (107) forms a recess (407) in a part of the detection wiring that overlaps with the facing section and a depth of the recess (407) is formed such that a distance between a bottom surface of the recess (407) and the detection wiring is greater than a distance between the detection wiring and the low-potential conductor. [5] Power semiconductor device (100) according to claim 4, wherein a width of the recess (407) of the second metal section (107) is formed such that it is larger than a width of the detection wiring.

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