SEMICONDUCTOR COMPONENT
Patent Information
- Application Number
- DE112018002152
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2018-04-16
- Filing Date
- 2018-04-18
- Publication Date
- 2025-10-09
- Estimated Expiration
- 2038-04-18
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a semiconductor device provided with a plurality of switching elements. STATE OF THE ART
[0002] A semiconductor device comprising a plurality of electrically coupled switching elements, such as MOSFETs, is known per se. Such a semiconductor device may comprise a housing made of a synthetic resin and a circuit board supported by the housing. The switching elements are electrically connected to the circuit board. The housing and the circuit board surround a space that may be filled with a sealing resin, such as a silicone gel. The switching elements are covered with the sealing resin.
[0003] In recent years, semiconductor devices with comparatively high rated voltages have become increasingly required in areas with tropical climates near / on the equator. In tropical areas, semiconductor devices are housed in high-temperature and high-humidity environments. For a semiconductor device to operate stably in such an environment, it is desirable for the semiconductor device to pass the H3TRB (High Humidity High Temperature Reverse Bias) test. The H3TRB test estimates the endurance time (unit: hours) of a semiconductor device when operated at 80% of its rated DC voltage under high-temperature and high-humidity conditions (temperature: 85°C, humidity: 85%). In the H3TRB test, semiconductor devices with an endurance time of 1000 hours or more are considered acceptable.Semiconductor devices accepted by this test are expected to operate stably under high temperature and high humidity conditions.
[0004] By conducting the H3TRB test on the semiconductor devices described above, the inventors found that the device lifetime is likely to be shorter than 1000 hours. When moisture penetrates the sealing resin of a semiconductor device placed in high-temperature and high-humidity conditions, the dielectric breakdown voltage of the sealing resin deteriorates, which may allow leakage current in the switching elements. If the leakage current reaches the circuit board, at least one of the switching elements may be damaged, and as a result, the device lifetime is shortened. At a higher rated voltage, a semiconductor device tends to have a shorter lifetime. Therefore, to operate stably under high-temperature and high-humidity conditions, a semiconductor device may need to pass the H3TRB test for the desired rated voltage as a criterion.
[0005] Further semiconductor components are known from the documents JP 2013- 183 038 A, US 2014 / 0 124 915 A1, DE 11 2015 002 024 T5, JP 2013- 16 684 A and JP H07 - 30 015 A. SUMMARY OF THE INVENTION
[0006] In view of the above circumstances, the present disclosure aims to provide a semiconductor device capable of stably operating under high temperature and high humidity conditions.
[0007] According to the present disclosure, a semiconductor device is provided having the features of claim 1. Advantageous embodiments are defined in the subclaims.
[0008] Other features and advantages of the present disclosure will become apparent from the following detailed description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a semiconductor device according to a first embodiment of the present disclosure; Fig. 2 a plan view of the Fig. 1 semiconductor component shown; Fig. 3 is a plan view of the Fig. 1 (as seen through a sealing resin, a moisture-resistant layer, and a top plate). Fig. 4 is a front view of the Fig. 1 semiconductor component; Fig. 5 is a right side view of the Fig. 1 semiconductor component; Fig. 6 is a left side view of the Fig. 1 semiconductor component; Fig. 7 is a bottom view of the Fig. 1 semiconductor component; Fig. Figure 8 shows a right section (near the first substrate) of Fig. 3 in enlargement; Fig. Figure 9 shows a left section (near the first substrate) of Fig. 3 in enlargement; Fig. Figure 10 shows a middle section (near the first substrate) of Fig. 3 in enlargement; Fig. 11 is a cross-sectional view taken along the line XI-XI in Fig. 3 is drawn; Fig. 12 is a cross-sectional view taken along the line XII-XII in Fig. 3 is drawn; Fig. 13 is a cross-sectional view taken along the line XIII-XIII in Fig. 3 is drawn; Fig. 14 is a cross-sectional view taken along the line XIV-XIV in Fig. 3 is drawn; Fig. 15 shows a section of Fig. 3 (a switching element and a protective element bonded to an upper arm mounting layer) in enlargement; Fig. 16 is a cross-sectional view taken along the line XVI-XVI in Fig. 15 is drawn; Fig. 17 is a cross-sectional view taken along the line XVII-XVII in Fig. 15 is drawn; Fig. 18 shows a section of Fig. 3 (a switching element and a protective element bonded to a forearm mounting layer) in magnification; Fig. 19 is a cross-sectional view taken along the line XIX-XIX in Fig. 18 is drawn; Fig. 20 is a cross-sectional view taken along the line XX-XX in Fig. 18 is drawn; Fig. 21 is a circuit diagram of the Fig. 1 semiconductor component; Fig. 22 shows a section of Fig. 16 in magnification; Fig. 23 is a cross-sectional view showing a portion of a semiconductor device of a comparative example (a switching element bonded to the upper arm layer) in an enlarged scale; Fig. 24 is a cross-sectional view showing a portion of a semiconductor device (a switching element and a protection element bonded to the upper arm layer) according to a first modification of the first embodiment of the present disclosure; Fig. 25 is a cross-sectional view showing a portion of a semiconductor device (a switching element and a protection element bonded to the underarm layer) according to the first modification of the first embodiment of the present disclosure; Fig. 26 is a plan view showing a portion of a semiconductor device (a switching element and a protection element bonded to the upper arm mounting layer) according to a second modification of the first embodiment of the present disclosure; Fig. 27 is a cross-sectional view taken along the line XXVII-XXVII in Fig. 26 is drawn; Fig. 28 is a cross-sectional view taken along the line XXVIII-XXVIII in Fig. 26 is drawn; Fig. 29 is a plan view showing a portion of a semiconductor device (a switching element and a protection element bonded to the underarm mounting layer) according to the second modification of the first embodiment of the present disclosure; Fig. 30 is a cross-sectional view taken along the line XXX-XXX in Fig. 29 is drawn; Fig. 31 is a cross-sectional view taken along the line XXXI-XXXI in Fig. 29 is drawn; Fig. 32 is a plan view showing a portion of a semiconductor device (a switching element and a protection element bonded to the upper arm mounting layer) according to a third modification of the first embodiment of the present disclosure; Fig. 33 is a cross-sectional view taken along the line XXXIII-XXXIII in Fig. 32 is drawn; Fig. 34 is a cross-sectional view taken along the line XXXIV-XXXIV in Fig. 32 is drawn; Fig. 35 is a plan view showing a portion of a semiconductor device (a switching element and a protection element bonded to the underarm mounting layer) according to the third modification of the first embodiment of the present disclosure; Fig. 36 is a cross-sectional view taken along the line XXXVI-XXXVI in Fig. 35 is drawn; Fig. 37 is a cross-sectional view taken along the line XXXVII-XXXVII in Fig. 35 is drawn; Fig. 38 is a plan view showing a portion of a semiconductor device (a switching element and a protection element bonded to the upper arm mounting layer) according to a fourth modification of the first embodiment of the present disclosure; Fig. 39 is a cross-sectional view taken along the line XXXIX-XXXIX in Fig. 38 is drawn; Fig. 40 is a cross-sectional view taken along the line XL-XL in Fig. 38 is drawn; Fig. 41 is a plan view showing a portion of a semiconductor device (a switching element and a protection element bonded to the underarm mounting layer) according to the fourth modification of the first embodiment of the present disclosure; Fig. 42 is a cross-sectional view taken along the line XLII-XLII in Fig. 41 is drawn; Fig. 43 is a cross-sectional view taken along the line XLIII-XLIII in Fig. 41 is drawn; Fig. 44 is a plan view showing a portion of a semiconductor device (a switching element and a protection element bonded to the upper arm mounting layer) according to a fifth modification of the first embodiment of the present disclosure; Fig. 45 is a cross-sectional view taken along the line XLV-XLV in Fig. 44 is drawn; Fig. 46 is a cross-sectional view taken along the line XLVI-XLVI in Fig. 45 is drawn; Fig. 47 is a plan view showing a portion of the semiconductor device (a switching element and a protection element bonded to the underarm mounting layer) according to the fifth modification of the first embodiment of the present disclosure; Fig. 48 is a cross-sectional view taken along the line XLVIII-XLVIII in Fig. 47 is drawn; Fig. 49 is a cross-sectional view taken along the line XLIX-XLIX in Fig. 47 is drawn; Fig. 50 shows test results based on variations in the thicknesses of the moisture-resistant layer of the semiconductor device according to the fourth modification of the first embodiment of the present disclosure; Fig. 51 shows results of the H3TRB test on the semiconductor device according to the fourth modification of the first embodiment of the present disclosure and the semiconductor device of the comparative example; Fig. 52 is a plan view showing a portion of a semiconductor device (a switching element and a protection element bonded to the upper arm mounting layer) according to a second embodiment of the present disclosure; Fig. 53 is a cross-sectional view taken along the line LIII-LIII in Fig. 52 is drawn; Fig. 54 is a cross-sectional view taken along the line LIV-LIV in Fig. 52 is drawn; Fig. 55 is a plan view showing a portion of the semiconductor device (a switching element and a protection element bonded to the underarm mounting layer) according to the second embodiment of the present disclosure; Fig. 56 is a cross-sectional view taken along the line LVI-LVI in Fig. 55 is drawn; and Fig. 57 is a cross-sectional view taken along the line LVII-LVII in Fig. 55 is drawn. MODE FOR CARRYING OUT THE INVENTION
[0009] Modes for carrying out the disclosure (hereinafter referred to as embodiments) will be described below with reference to the accompanying drawings. [First embodiment]
[0010] With reference to Fig. 1 to 23, a semiconductor device A10 according to a first embodiment of the present disclosure will be described. The semiconductor device A10 includes a substrate 11, a first mounting layer 211, a second mounting layer 221, a third mounting layer 231, switching elements 31, a moisture-resistant layer 51, and a sealing resin 52. Of these, the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231 represent examples of the "mounting layer" as set forth in the appended claims of the present disclosure. In addition to these, the semiconductor device A10 further includes a first electrically conductive layer 212, a second electrically conductive layer 222, a third electrically conductive layer 232, a power terminal 24, an output terminal 25, an electrically conductive connecting element 261, protection elements 32, wires 41, a heat sink 61, and a package 70.Of these, the first electrically conductive layer 212, the second electrically conductive layer 222, and the third electrically conductive layer 232 represent examples of the "electrically conductive layer" as set forth in the appended claims of the present disclosure. The supply terminal 24 includes a first supply terminal 24A and a second supply terminal 24B. For ease of understanding, FIG. Fig. 3 a view when viewed through the moisture-resistant layer 51, the sealing resin 52 and a top plate 79. In Fig. 3, the line XI-XI and the line XII-XII are indicated by dotted lines. Fig. 11 and Fig. 12, an illustration of the moisture-resistant layer 51 is omitted.
[0011] The Fig. The semiconductor device shown in Figure 1 is a power module. The semiconductor device 10A can be used for inverter devices of various electrical products. As shown in Fig. 1 and Fig. As shown in Figure 2, the semiconductor device A10 is rectangular when viewed in the thickness direction z of the substrate 11. For convenience of explanation, a direction perpendicular to the thickness direction z of the substrate 11 (hereinafter simply "thickness direction z") is referred to as the "first direction x1." The direction perpendicular to both the thickness direction z and the first direction x1 is referred to as the "second direction x2." The longitudinal direction of the semiconductor device A10 is the second direction x2.
[0012] The substrate 11 is an electrically insulating member on which the mounting layer (the first mounting layer 211, the second mounting layer 221 and the third mounting layer 231) and the electrically conductive layer (the first electrically conductive layer 212, the second electrically conductive layer 222 and the third electrically conductive layer 232) are arranged, as shown in Fig. 3. The substrate 11 has three sections, namely a first substrate 11A, a second substrate 11B, and a third substrate 11C. The first substrate 11A, the second substrate 11B, and the third substrate 11C are spaced apart from each other in the second direction x2. In the second direction x2, the third substrate 11C is arranged between the first substrate 11A and the second substrate 11B. In contrast to this embodiment, the substrate 11 may have two sections, namely the first substrate 11A and the second substrate 11B, or it may have only a single section. As shown in Fig. 11, each of the first substrate 11A, the second substrate 11B, and the third substrate 11C has a front surface 111 and a back surface 112 facing away from each other in the thickness direction z.
[0013] The substrate 11 is made of a ceramic with excellent thermal conductivity. Examples of such a ceramic include aluminum nitride (AlN). A DBC (Direct Bonding Copper) substrate having copper foils (Cu foils) bonded to the front surface 111 and the back surface 112 can be used as the substrate 11. By using a DBC substrate, the mounting layer and the electrically conductive layer can be easily formed by patterning the copper foil bonded to the front surface 111. The copper foil bonded to the back surface 112 can be formed into a heat transfer layer 62 (described below).
[0014] As in Fig. 3 and Fig. As shown in Figure 8, the first mounting layer 211, the first electrically conductive layer 212, a first gate layer 213, a first detection layer 214, and a thermistor mounting layer 215 are arranged on the front surface 111 of the first substrate 11A. These are electrically conductive elements made of a thin metal film, such as copper foil. The surfaces of these layers can be plated with silver (Ag), for example.
[0015] As in Fig. As shown in Figure 8, switching elements 31 and protection elements 32 are electrically bonded to the first mounting layer 211. The first mounting layer 211 includes a first upper arm mounting layer 211A and a first lower arm mounting layer 211B.
[0016] As in Fig. 8, the first upper arm mounting layer 211A is connected to one end of the first substrate 11A (upper side in Fig. 8) in the first direction x1. The first upper arm mounting layer 211A has the shape of a strip extending along the second direction x2. Three switching elements 31 and three protection elements 32 are electrically bonded to the first upper arm mounting layer 211A. Note that the number of switching elements 31 and the number of protection elements 32 to be electrically bonded to the first upper arm mounting layer 211A is not limited to three. On the first upper arm mounting layer 211A, both the switching elements 31 and the protection elements 32 are aligned in the second direction x2. The first upper arm mounting layer 211A is formed with a first supply pad 211C in the shape of a strip extending along the first direction x1 at one end, in the second direction x2, near the housing 70. The first supply pad 211C is electrically connected to the first supply terminal 24A.
[0017] As in Fig. As shown in Figure 8, the first forearm mounting layer 211B is arranged, in the first direction x1, between the first upper arm mounting layer 211A and the first electrically conductive layer 212. The first forearm mounting layer 211B has the shape of a strip extending along the second direction x2. Three switching elements 31 and three protective elements 32 are electrically bonded to the first forearm mounting layer 211B. It should be noted that the number of switching elements 31 and the number of protective elements 32 to be electrically bonded to the first forearm mounting layer 211B is not limited to three. On the first forearm mounting layer 211B, both the switching elements 31 and the protective elements 32 are aligned in the second direction x2. As shown in Fig. 15, the first lower arm mounting layer 211B is electrically connected via wires 41 to both the front surface electrodes 311 (described below) of the switching elements 31 and anode electrodes 321 (described below) of the protection elements 32, which are electrically bonded to the first upper arm mounting layer 211A.
[0018] As in Fig. 8 and Fig. 18, the first electrically conductive layer 212 is electrically connected via wires 41 to the front surface electrodes 311 of the switching elements 31 and the anode electrodes 321 of the protection elements 32, which are electrically bonded to the first underarm mounting layer 211B. The first electrically conductive layer 212 is connected to the other end of the first substrate 11A (lower side in Fig. 8) in the first direction x1. The first electrically conductive layer 212 has the shape of a strip extending along the second direction x2. The first electrically conductive layer 212 is formed with a second supply pad 212A in the shape of a strip extending along the first direction x1 at one end, in the second direction x2, near the housing 70. The second supply pad 212A is electrically connected to the second supply terminal 24B.
[0019] As in Fig. 15 and Fig. As shown in Figure 18, the first gate layer 213 is electrically connected via the first gate wires 421 to gate electrodes 313 (described below) of the switching elements 31, which are electrically bonded to the first mounting layer 211. The first gate layer 213 has the shape of a stripe extending along the second direction x2 and faces the switching elements 31 when viewed in the thickness direction z. The first gate layer 213 includes a first upper arm gate layer 213A and a first lower arm gate layer 213B.
[0020] As in Fig. 8, the first upper arm gate layer 213A is arranged, in the first direction x1, between the first upper arm mounting layer 211A and the housing 70. When viewed in the thickness direction z, the first upper arm gate layer 213A faces the switching elements 31, which are electrically bonded to the first upper arm mounting layer 211A. As shown in Fig. 15, the first upper arm gate layer 213A is electrically connected via first gate wires 421 to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the first upper arm mounting layer 211A.
[0021] As in Fig. 8, the first underarm gate layer 213B is arranged, in the first direction x1, between the first underarm mounting layer 211B and the first electrically conductive layer 212. When viewed in the thickness direction z, the first underarm gate layer 213B faces the switching elements 31, which are electrically bonded to the first underarm mounting layer 211B. As shown in Fig. 18, the first underarm gate layer 213B is electrically connected via first gate wires 421 to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the first underarm mounting layer 211B.
[0022] As in Fig. 15 and Fig. As shown in Figure 18, the first detection layer 214 is electrically connected via first detection wires 431 to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the first mounting layer 211. The first detection layer 214 has the shape of a stripe extending along the second direction x2 and faces the switching elements 31 when viewed in the thickness direction z. The first detection layer 214 includes a first upper arm detection layer 214A and a first lower arm detection layer 214B.
[0023] As in Fig. 8, the first upper arm detection layer 214A is arranged, in the first direction x1, between the first upper arm mounting layer 211A and the first upper arm gate layer 213A. When viewed in the thickness direction z, the first upper arm detection layer 214A faces the switching elements 31, which are electrically bonded to the first upper arm mounting layer 211A. As shown in Fig. 15, the first upper arm detection layer 214A is electrically connected via first detection wires 431 to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the first upper arm mounting layer 211A.
[0024] As in Fig. As shown in Figure 8, the first underarm detection layer 214B is arranged, in the first direction x1, between the first underarm mounting layer 211B and the first underarm gate layer 213A. The first underarm detection layer 214B has the shape of an L-shaped strip, with a part extending in the first direction x1 and a part extending in the second direction x2. When viewed in the thickness direction z, the part extending in the second direction x2 faces the switching elements 31, which are electrically bonded to the first underarm mounting layer 211B. As shown in Fig. 18, the first forearm detection layer 214B is electrically connected via first detection wires 431 to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the first forearm mounting layer 211B.
[0025] As in Fig. As shown in Figure 8, a thermistor 33 is electrically bonded to the thermistor mounting layer 215. The thermistor mounting layer 215 is disposed near a corner of the first substrate 11A. The thermistor mounting layer 215 is surrounded by the first upper arm mounting layer 211A, the first upper arm gate layer 213A, and the first upper arm detection layer 214A. The thermistor mounting layer 215 has a pair of portions spaced apart from each other in the second direction x2. The positive electrode of the thermistor 33 is electrically bonded to one of these portions, while the negative electrode of the thermistor 33 is electrically bonded to the other of these portions.
[0026] As in Fig. 3 and Fig. As shown in Figure 9, the second mounting layer 211, the second electrically conductive layer 222, a second gate layer 223, and a second detection layer 224 are arranged on the front surface 111 of the second substrate 11B. These are electrically conductive elements made of a thin metal film, such as a copper foil. The surfaces of this layer can be plated with silver, for example.
[0027] As in Fig. As shown in Figure 9, switching elements 31 and protection elements 32 are electrically bonded to the second mounting layer 221. The second mounting layer 221 includes a second upper arm mounting layer 221A and a second lower arm mounting layer 221B.
[0028] As in Fig. 9, the second upper arm mounting layer 221A is connected to one end of the second substrate 11B (upper side in Fig. 9) in the first direction x1. The second upper arm mounting layer 221A has the shape of a strip extending along the second direction x2. Three switching elements 31 and three protection elements 32 are electrically bonded to the second upper arm mounting layer 221A. Note that the number of switching elements 31 and the number of protection elements 32 to be electrically bonded to the second upper arm mounting layer 221A is not limited to three. On the second upper arm mounting layer 221A, both the switching elements 31 and the protection elements 32 are aligned in the second direction x2.
[0029] As in Fig. As shown in Figure 9, the second forearm mounting layer 221B is arranged, in the first direction x1, between the second upper arm mounting layer 221A and the second electrically conductive layer 222. The second forearm mounting layer 221B has the shape of a strip extending along the second direction x2. Three switching elements 31 and three protective elements 32 are electrically bonded to the second forearm mounting layer 221B. It should be noted that the number of switching elements 31 and the number of protective elements 32 to be electrically bonded to the second forearm mounting layer 221B is not limited to three. On the second forearm mounting layer 221B, both the switching elements 31 and the protective elements 32 are aligned in the second direction x2. As shown in Fig. 15, the second lower arm mounting layer 221B is electrically connected via wires 41 to the front surface electrodes 311 of the switching elements 31 and the anode electrodes 321 of the protection elements 32, which are electrically bonded to the second upper arm mounting layer 221A. The second lower arm mounting layer 221B is formed with a first output pad 221C in the shape of a strip extending along the first direction x1 at one end, in the second direction x2, near the housing 70. In the second direction x2, the output pad 221C is located near both the second upper arm mounting layer 221A and the second electrically conductive layer 222. The output pad 221C is electrically connected to the output terminal 25.
[0030] As in Fig. 9 and Fig. 18, the second electrically conductive layer 222 is electrically connected via wires 41 to the front surface electrodes 311 of the switching elements 31 and the anode electrodes 321 of the protection elements 32, which are electrically bonded to the second underarm mounting layer 221B. The second electrically conductive layer 222 is connected to the other end of the second substrate 11B (lower side in Fig. 9) in the first direction x1. The second electrically conductive layer 222 has the shape of a strip extending along the second direction x2.
[0031] As in Fig. 15 and Fig. As shown in Figure 18, the second gate layer 223 is electrically connected via first gate wires 421 to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the second mounting layer 221. The second gate layer 223 has the shape of a stripe extending along the second direction x2 and faces the switching elements 31 when viewed in the thickness direction z. The second gate layer 223 includes a second upper arm gate layer 223A and a second lower arm gate layer 223B.
[0032] As in Fig. 9, the second upper arm gate layer 223A is arranged, in the first direction x1, between the second upper arm mounting layer 221A and the housing 70. When viewed in the thickness direction z, the second upper arm gate layer 223A faces the switching elements 31, which are electrically bonded to the second upper arm mounting layer 221A. As shown in Fig. 15, the second upper arm gate layer 223A is electrically connected via first gate wires 421 to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the second upper arm mounting layer 221A.
[0033] As in Fig. 9, the second underarm gate layer 223B is arranged, in the first direction x1, between the second underarm mounting layer 221B and the second electrically conductive layer 222. When viewed in the thickness direction z, the second underarm gate layer 223B faces the switching elements 31, which are electrically bonded to the second underarm mounting layer 221B. As shown in Fig. 18, the second underarm gate layer 223B is electrically connected via first gate wires 421 to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the second underarm mounting layer 221B.
[0034] As in Fig. 15 and Fig. As shown in Figure 18, the second detection layer 224 is electrically connected via first detection wires 431 to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the second mounting layer 221. The second detection layer 224 has the shape of a stripe extending along the second direction x2 and faces the switching elements 31 when viewed in the thickness direction z. The second detection layer 224 includes a second upper arm detection layer 224A and a second lower arm detection layer 224B.
[0035] As in Fig. 9, the second upper arm detection layer 224A is arranged, in the first direction x1, between the second upper arm mounting layer 221A and the second upper arm gate layer 223A. When viewed in the thickness direction z, the second upper arm detection layer 224A faces the switching elements 31, which are electrically bonded to the second upper arm mounting layer 221A. As shown in Fig. 15, the second upper arm detection layer 224A is electrically connected via first detection wires 431 to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the second upper arm mounting layer 221A.
[0036] As in Fig. 9, the second underarm detection layer 224B is arranged, in the first direction x1, between the second underarm mounting layer 221B and the second underarm gate layer 223B. When viewed in the thickness direction z, the second underarm detection layer 224B faces the switching elements 31, which are electrically bonded to the second underarm mounting layer 221B. As shown in Fig. 18, the second forearm detection layer 224B is electrically connected via first detection wires 431 to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the second forearm mounting layer 221B.
[0037] As in Fig. 3 and Fig. As shown in Figure 10, the third mounting layer 231, the third electrically conductive layer 232, a third gate layer 233, and a third detection layer 234 are arranged on the front surface 111 of the third substrate 11C. These are electrically conductive elements made of a thin metal film, such as a copper foil. The surfaces of this layer can be plated with silver, for example.
[0038] As in Fig. As shown in Figure 10, the switching elements 31 and protection elements 32 are electrically bonded to the third mounting layer 231. The third mounting layer 231 includes a third upper arm mounting layer 231A and a third lower arm mounting layer 231B.
[0039] As in Fig. 10, the third upper arm mounting layer 231A is connected to one end of the third substrate 11C (upper side in Fig. 10) in the first direction x1. The third upper arm mounting layer 231A has the shape of a strip extending along the second direction x2. Two switching elements 31 and two protection elements 32 are electrically bonded to the third upper arm mounting layer 231A. Note that the number of switching elements 31 and the number of protection elements 32 to be electrically bonded to the third upper arm mounting layer 231A is not limited to two. On the third upper arm mounting layer 231A, both the switching elements 31 and the protection elements 32 are aligned in the second direction x2.
[0040] As in Fig. As shown in Figure 10, the third lower arm mounting layer 231B is arranged between the third upper arm mounting layer 231A and the third electrically conductive layer 232 in the first direction x1. The third lower arm mounting layer 231B has the shape of a strip extending along the second direction x2. Two switching elements 31 and two protective elements 32 are electrically bonded to the third lower arm mounting layer 231B. Note that the number of switching elements 31 and the number of protective elements 32 to be electrically bonded to the third upper arm mounting layer 231B is not limited to two. On the third lower arm mounting layer 231B, both the switching elements 31 and the protective elements 32 are aligned in the second direction x2. As shown in Fig. 15, the third lower arm mounting layer 231B is electrically connected via wires 41 to the front surface electrodes 311 of the switching elements 31 and the anode electrodes 321 of the protection elements 32, which are electrically bonded to the third upper arm mounting layer 231A.
[0041] As in Fig. 10 and Fig. 18, the third electrically conductive layer 232 is electrically connected via wires 41 to the front surface electrodes 311 of the switching elements 31 and the anode electrodes 321 of the protection elements 32, which are electrically bonded to the third underarm mounting layer 231B. The third electrically conductive layer 232 is connected to the other end of the third substrate 11C (lower side in Fig. 10) in the first direction x1. The third electrically conductive layer 232 has the shape of a strip extending along the second direction x2.
[0042] As in Fig. 15 and Fig. As shown in Figure 18, the third gate layer 233 is electrically connected via first gate wires 421 to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the third mounting layer 231. The third gate layer 233 has the shape of a stripe extending along the second direction x2 and faces the switching elements 31 when viewed in the thickness direction z. The third gate layer 233 includes a third upper arm gate layer 233A and a third lower arm gate layer 233B.
[0043] As in Fig. 10, the third upper arm gate layer 233A is arranged, in the first direction x1, between the third upper arm mounting layer 231A and the housing 70. When viewed in the thickness direction z, the third upper arm gate layer 233A faces the switching elements 31, which are electrically bonded to the third upper arm mounting layer 231A. As shown in Fig. 15, the third upper arm gate layer 233A is electrically connected via first gate wires 421 to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the third upper arm mounting layer 231A.
[0044] As in Fig. As shown in Figure 10, the third underarm gate layer 233B is arranged, in the first direction x1, between the third underarm mounting layer 231B and the third electrically conductive layer 232. The third underarm gate layer 233B has the shape of an L-shaped strip, with a part extending in the first direction x1 and a part extending in the second direction x2. When viewed in the thickness direction z, the part extending in the second direction x2 faces the switching elements 31, which are electrically bonded to the third underarm mounting layer 231B. As shown in Fig. 18, the third underarm gate layer 233B is electrically connected via first gate wires 421 to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the third underarm mounting layer 231B.
[0045] As in Fig. 15 and Fig. As shown in Figure 18, the third detection layer 234 is electrically connected via first detection wires 431 to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the third mounting layer 231. The third detection layer 234 has the shape of a stripe extending along the second direction x2 and faces the switching elements 31 when viewed in the thickness direction z. The third detection layer 234 includes a third upper arm detection layer 234A and a third lower arm detection layer 234B.
[0046] As in Fig. 10, the third upper arm detection layer 234A is arranged, in the first direction x1, between the third upper arm mounting layer 231A and the third upper arm gate layer 233A. When viewed in the thickness direction z, the third upper arm detection layer 234A faces the switching elements 31, which are electrically bonded to the third upper arm mounting layer 231A. As shown in Fig. 15, the third upper arm detection layer 234A is electrically connected via first detection wires 431 to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the third upper arm mounting layer 231A.
[0047] As in Fig. 10, the third underarm detection layer 234B is arranged, in the first direction x1, between the third underarm mounting layer 231B and the third underarm gate layer 233B. When viewed in the thickness direction z, the third underarm detection layer 234B faces the switching elements 31, which are electrically bonded to the third underarm mounting layer 231B. As shown in Fig. 18, the third forearm detection layer 234B is electrically connected via first detection wires 431 to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the third forearm mounting layer 231B.
[0048] The first upper arm mounting layer 211A, the second upper arm mounting layer 221A, and the third upper arm mounting layer 231A each correspond to portions of the "upper arm mounting layer" as set forth in the appended claims of the present disclosure. The first forearm mounting layer 211B, the second forearm mounting layer 221B, and the third forearm mounting layer 231B each correspond to portions of the "forearm mounting layer" as set forth in the appended claims of the present disclosure.
[0049] As in Fig. 2 and Fig. 3, the power supply terminal 24 is one element of an external connection terminal provided in the semiconductor device A10. As described above, the power supply terminal 24 includes a first power supply terminal 24A and a second power supply terminal 24B. The power supply terminal 24 is supported on the case 70 and connected to a DC power supply arranged outside the semiconductor device A10. The power supply terminal 24 is made of a thin metal plate, such as a copper plate. The surface of the thin metal plate may be plated with nickel (Ni). The first power supply terminal 24A is the positive electrode (P terminal) of the semiconductor device A10. The second power supply terminal 24B is the negative electrode (N terminal) of the semiconductor device A10. The first power supply terminal 24A and the second power supply terminal 24B are spaced apart from each other in the first direction x1.The first supply terminal 24A and the second supply terminal 24B have the same shape.
[0050] As in Fig. 11, the supply terminal 24 is bent into a hook shape when viewed in the first direction x1. The supply terminal 24 is formed with a coupling hole 241 that penetrates the terminal in the thickness direction z at a portion exposed to the outside of the semiconductor device A10 and extends perpendicular to the thickness direction z. A fastening member, such as a bolt, is inserted into the coupling hole 241. As shown in Fig. 8, a connecting element 242 having electrical conductivity is connected to a portion of the supply terminal 24 arranged inside the housing 70 and extending perpendicular to the thickness direction z. For example, the connecting element 242 comprises a plurality of wires made of aluminum (Al). The connecting element 242, which is connected to the first supply terminal 24A, is connected at its other end to the supply pad 211C of the first upper arm mounting layer 211A. Therefore, in this connecting element 242, the first supply terminal 24A is electrically connected to the first upper arm mounting layer 211A. The connecting element 242, which is connected to the second supply terminal 24B, is connected at its other end to the second supply pad 212A of the first electrically conductive layer 212.Therefore, in this connecting element 242, the second supply terminal 24B is electrically connected to the first electrically conductive layer 212.
[0051] As in Fig. 2 and Fig. 3, the output terminal 25 is one element of an external connection terminal provided in the semiconductor device A10. The output terminal 25 is divided into two, namely, a first output terminal 25A and a second output terminal 25B. Note that the output terminal 25 may be configured as a single unit without being divided into multiple parts. The output terminal 25 is supported on the case 70 and connected to a driving target, such as a motor, arranged outside the semiconductor device A10. The output terminal 25 is arranged opposite the power supply terminal 24 across the substrate 11 in the second direction x2. The output terminal 25 is made of the same thin metal film as the power supply terminal 24. The surface of the thin metal plate may be plated with nickel.The first output terminal 25A and the second output terminal 25B are connected in parallel to the second lower arm mounting layer 221B. The first output terminal 25A and the second output terminal 25B are connected to a drive target of the semiconductor device A10, which is arranged externally. In the second direction x2, the first output terminal 25A faces the first supply terminal 24A, while the second output terminal 25B faces the second supply terminal 24B. The first output terminal 25A and the second output terminal 25B are spaced apart from each other in the first direction x1. The first output terminal 25A and the second output terminal 25B have the same shape.
[0052] As in Fig. 11, the output terminal 25 is bent into a hook shape when viewed in the first direction x1. The output terminal 25 is formed with a coupling hole 251 that penetrates the terminal in the thickness direction z at a portion exposed to the outside of the semiconductor device A10 and extends perpendicular to the thickness direction z. A fastening member, such as a bolt, is inserted into the coupling hole 251. As shown in Fig. As shown in Figure 9, a connecting element 252 having electrical conductivity is connected to a portion of the output terminal 25 disposed inside the housing 70 and extending perpendicular to the thickness direction z. For example, the connecting element 252 comprises a plurality of wires made of aluminum. The connecting element 252 connected to the output terminal 25 is connected at its other end to the output pad 221C of the second lower arm mounting layer 221B disposed on the second substrate 11B. Therefore, in the connecting element 25, the output terminal 25 is electrically connected to the second lower arm mounting layer 221B.
[0053] As in Fig. 10, the electrically conductive connecting element 261 connects the first mounting layer 211 and the third mounting layer 231 to each other, and also connects the second mounting layer 221 and the third mounting layer 231 to each other. Therefore, the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231 are electrically connected to each other via the electrically conductive connecting element 261. In addition, as shown in Fig. As shown in Figure 10, the electrically conductive connecting element 261 connects the first electrically conductive layer 212 and the third electrically conductive layer 232 to each other, and also connects the second electrically conductive layer 222 and the third electrically conductive layer 232 to each other. Therefore, the first electrically conductive layer 212, the second electrically conductive layer 222, and the third electrically conductive layer 232 are electrically connected to each other via the electrically conductive connecting element 261. For example, the electrically conductive connecting element 261 includes a plurality of wires made of aluminum.
[0054] As in Fig. 10, the electrically conductive connecting element 261 includes a first part 261A, a second part 261B, and a third part 261C. All of the first part 261A, the second part 261B, and the third part 261C extend in the second direction x2. The first part 261A connects the first upper arm mounting layer 211A and the third upper arm mounting layer 231A to each other, and also connects the second upper arm mounting layer 221A and the third upper arm mounting layer 231A to each other. Therefore, the first upper arm mounting layer 211A and the second upper arm mounting layer 221A are electrically connected to each other via the first part 261A. The second part 261B connects the first forearm mounting layer 211B and the third forearm mounting layer 231B to each other, and also connects the second forearm mounting layer 221B and the third forearm mounting layer 231B to each other.Therefore, the first underarm mounting layer 211B and the second underarm mounting layer 221B are electrically connected to each other via the second part 261B. The third part 261C connects the first electrically conductive layer 212 and the third electrically conductive layer 232 to each other, and also connects the second electrically conductive layer 222 and the third electrically conductive layer 232 to each other. Therefore, the first electrically conductive layer 212 and the second electrically conductive layer 222 are electrically connected to each other via the third part 261C.
[0055] As in Fig. As shown in Figure 10, first electrically conductive connecting elements 262 connect the first gate layer 213 and the third gate layer 233 to each other, and also connect the second gate layer 223 and the third gate layer 233 to each other. Therefore, the first gate layer 213, the second gate layer 223, and the third gate layer 233 are electrically connected to each other via the first electrically conductive elements 262. For example, the first electrically conductive connecting elements 262 are wires made of aluminum. All of the first electrically conductive elements 262 extend in the second direction x2 and may consist of four first electrically conductive elements 262. The first of the first electrically conductive elements 262 connects the first upper arm gate layer 213A and the third upper arm gate layer 244A.The second of the first electrically conductive elements 262 connects the second upper arm gate layer 223A and the third upper arm gate layer 244A. The third of the first electrically conductive elements 262 connects the first lower arm gate layer 213B and the third lower arm gate layer 244A. The fourth of the first electrically conductive elements 262 connects the second lower arm gate layer 223B and the third lower arm gate layer 244A.
[0056] As in Fig. As shown in Figure 10, second electrically conductive connecting elements 263 connect the first detection layer 214 and the third detection layer 234 to each other, and also connect the second detection layer 224 and the third detection layer 234 to each other. Therefore, the first detection layer 214, the second detection layer 224, and the third detection layer 234 are electrically connected to each other via the second electrically conductive elements 263. For example, the second electrically conductive connecting elements 263 are wires made of aluminum. Each of the second electrically conductive elements 263 extends in the second direction x2 and may consist of four second electrically conductive elements 263. The first of the second electrically conductive elements 263 connects the first upper arm detection layer 214A and the third upper arm detection layer 234A.The second of the second electrically conductive elements 263 connects the second upper arm detection layer 224A and the third upper arm detection layer 234A. The third of the second electrically conductive elements 263 connects the first forearm detection layer 214B and the third forearm detection layer 234B. The fourth of the second electrically conductive elements 263 connects the second forearm detection layer 224B and the third forearm detection layer 234B.
[0057] As in Fig. 2 to 4, a gate terminal 27 is an element of an external connection terminal provided in the semiconductor device A10. The gate terminal 27 is connected to an externally arranged drive circuit (e.g., gate driver) for the semiconductor device A10. The gate terminal 27 is arranged to face the substrate 11 when viewed in the thickness direction z, and is supported on the housing 70. The gate terminal 27 protrudes in the same direction as the front surface 111 of the substrate 11 (along the thickness direction z). For example, the gate terminal 27 has the shape of a metal rod made of copper. The surface of the metal rod is plated with tin (Sn). Nickel plating may be provided between the surface of the metal rod and the tin plating. As shown in Fig. As shown in Figure 12, the gate terminal 27 is bent into a hook shape at its end located closer to the substrate 11 in the thickness direction z, thereby having a portion extending along the first direction x1. The gate terminal 27 includes a first gate terminal 27A and a second gate terminal 27B. Paired second gate wires 422 are connected to the first gate terminal 27A and the second gate terminal 27B. For example, the paired second gate wires 422 are made of aluminum.
[0058] As in Fig. As shown in Figure 10, the first gate terminal 27A is disposed near the second upper arm gate layer 223A so as to face the second substrate 11B when viewed in the thickness direction z. Therefore, the first gate terminal 27A is electrically connected to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, and the third upper arm mounting layer 231A.
[0059] As in Fig. As shown in FIG. 10, the second gate terminal 27B is disposed near the third underarm gate layer 233B so as to face the third substrate 11C when viewed in the thickness direction z. The second gate wire 422, which is connected to the second gate terminal 27B at one end, is connected to the third underarm gate layer 233B at the other end. Therefore, the second gate terminal 27B is electrically connected to the gate electrodes 313 of the switching elements 31, which are electrically bonded to the first underarm mounting layer 211B, the second underarm mounting layer 221B, and the third underarm mounting layer 231B.
[0060] As in Fig. As shown in Figures 2 to 4, a component current detection terminal 281 is an element of an external connection terminal provided in the semiconductor device A10. The component current detection terminal 281 is connected to an externally arranged control circuit for the semiconductor device A10. The component current detection terminal 281 is arranged to face the substrate 11 and is supported on the package 70. The component current detection terminal 281 protrudes in the same direction in which the gate terminal 27 protrudes along the thickness direction z. The component current detection terminal 281 is made of a metal rod made of the same material as the gate terminal 27. The component current detection terminal 281 has the same shape as the gate terminal 27.Therefore, the component current detection terminal 281 is bent into a hook shape at its end located closer to the substrate 11 in the thickness direction z, thereby having a portion extending along the first direction x1. The component current detection terminal 281 includes a first detection terminal 281A and a second detection terminal 281B. Paired second detection wires 432 are connected to the first detection terminal 281A and the second detection terminal 281B. For example, the paired second detection wires 432 are made of aluminum.
[0061] As in Fig. As shown in Fig. 10, the first detection terminal 281A is disposed near the second upper arm detection layer 224A so as to face the second substrate 11B when viewed in the thickness direction z, and is also located near the first gate terminal 27A. The second detection wire 432, which is connected to the first detection terminal 281A at one end, is connected to the second upper arm detection layer 224A at the other end. Therefore, the first detection terminal 281A is electrically connected to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, and the third upper arm mounting layer 231A.
[0062] As in Fig. 10, the second detection terminal 281B is disposed near the first underarm detection layer 214B so as to face the first substrate 11A when viewed in the thickness direction z, and is also located near the second gate terminal 27B. The second detection wire 432, which is connected to the second detection terminal 281B at one end, is connected to the first underarm detection layer 214B at the other end. Therefore, the second detection terminal 281B is electrically connected to the front surface electrodes 311 of the switching elements 31, which are electrically bonded to the first underarm mounting layer 211B, the second underarm mounting layer 221B, and the third underarm mounting layer 231B.
[0063] As in Fig. 2 to 4 and 9, a supply current detection terminal 281 is an element of an external connection terminal provided in the semiconductor device A10. The supply current detection terminal 282 is connected to an externally arranged control circuit for the semiconductor device A10 and is supported on the package 70. The supply current detection terminal 282 protrudes in the same direction in which the gate terminal 27 protrudes along the thickness direction z. The supply current detection terminal 28 is made of a metal bar made of the same material as the gate terminal 27. The supply current detection terminal 282 is arranged at the same position as the first gate terminal 27A and the first detection terminal 281A in the first direction x1, and is spaced from the first detection terminal 281A toward the first output terminal 25A in the second direction x2.The supply current detection terminal 282 is arranged in the first direction x1, near the second upper arm mounting layer 221A, so as to face the second substrate 11B. The supply current detection terminal 282 has the same shape as the gate terminal 27. Therefore, the supply current detection terminal 282 is bent into a hook shape at its end located closer to the second substrate 11B in the thickness direction z, thereby having a portion extending along the first direction x1. One end of a supply current detection wire 44 is connected to this end of the supply current detection terminal. The other end of the supply current detection wire 44 is connected to the second upper arm mounting layer 221A. Therefore, the supply current detection terminal 282 is electrically connected to the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, and the third upper arm mounting layer 231A.For example, the supply current detection wire 44 is made of aluminum.
[0064] As in Fig. 2 to 4 and 8, a pair of thermistor terminals 29 is an element of an external connection terminal provided in the semiconductor device A10. The paired thermistor terminals 29 are connected to an externally arranged control circuit for the semiconductor device A10 and are supported on the package 70. The paired thermistor terminal 29 protrudes in the same direction in which the gate terminal 27 protrudes along the thickness direction z. The paired thermistor terminals 29 are made of a metal bar made of the same material as the gate terminal 27. The paired thermistor terminals 29 are arranged at the same position as the first gate terminal 27A and the first detection terminal 28A in the first direction x1, and are spaced apart from the first gate terminal 27A toward the first supply terminal 24A in the second direction x2.The paired thermistor terminal 29 is arranged near the thermistor mounting layer 215 in the first direction x1, facing the first substrate 11A. The paired thermistor terminals 29 have the same shape as the gate terminal 27. Therefore, each of the paired thermistor terminals is bent into a hook shape at its end located closer to the first substrate 11A in the thickness direction z, thereby having a portion extending along the first direction x1. To this end of each of the paired thermistor terminals 29, one end of a corresponding one of the paired thermistor wires 45 is connected. The other ends of the paired thermistor wires 45 are connected to paired portions of the thermistor mounting layer 215. Therefore, the thermistor terminals 29 are electrically connected to the thermistor 33. For example, the paired thermistor wires 45 are made of aluminum.
[0065] As in Fig. 3, the switching elements 31 are semiconductor elements electrically bonded to each of the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231 and aligned therewith in the second direction x2. The switching elements 31 are rectangular when viewed in the thickness direction z (square in the semiconductor device A10). The switching elements 31 are MOSFETs (metal oxide semiconductor field-effect transistors) made of a semiconductor material composed mainly of silicon carbide (SiC). Note that the switching elements 31 are not limited to MOSFETs and may be IGBTs (insulated gate bipolar transistors). In the semiconductor device A10, the switching elements 31 are assumed to be n-channel MOSFETs made of a semiconductor material composed mainly of silicon carbide.In the semiconductor device A10, the switching elements 31 have a thickness of 400 µm or less, or preferably 150 µm or less. The breakdown voltage of the switching elements 31 is 1200 V or more.
[0066] As in Fig. As shown in FIGS. 15 to 20, each of the switching elements 31 has a front surface 31A, a back surface 31B, a side surface 31C, a front surface electrode 311, a back surface electrode 312, a gate electrode 313, and an insulating film 314. The front surface 31A, the back surface 31B, and the side surface 31C correspond, respectively, to the "first element front surface," the "first element back surface," and the "first element side surface" as set forth in the appended claims of the present disclosure. The front surface 31A faces in the same direction as the front surface 111 of the substrate 11 along the thickness direction z. The back surface 31B faces in the opposite direction to the front surface 31A. The switching elements 31 are electrically bonded to the first mounting layer 211, the second mounting layer 221 and the third mounting layer 231 with the back surfaces 31B facing the front surface 111.The side surface 31C is connected to both the front surface 31A and the rear surface 31B. The side surface 31C comprises a plurality of sections (four sections in the semiconductor device A10), each of which points in the first direction x1 or the second direction x2.
[0067] As in Fig. 15 to 20, the front surface electrode 311 is provided on the front surface 31A. A source current flows through the front surface electrode 311. The front surface electrode 311 includes a pair of first pads 311A and a pair of second pads 311B. The paired first pads 311A are portions of a front surface electrode 311 that are spaced apart from each other in the second direction x2, just like the paired second pads 311B. In each of the switching elements 31 electrically bonded to the first mounting layer 211, the second pads 311B are arranged on the other side of the paired first pads 311A in the first direction x1 than the first underarm mounting layer 211B or the first electrically conductive layer 212.The above-described positional relationship between the paired first pads 311A and the paired second pads 311B also applies to the switching elements 31 electrically bonded to the second mounting layer 221 or the third mounting layer 231.
[0068] As in Fig. As shown in Figure 15, in each of the switching elements 31 electrically bonded to the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, or the third upper arm mounting layer 231A, one end of the first detection wire 431 is connected to one of the paired second pads 311A. The other end of the first detection wire 431 is connected to the first upper arm detection layer 214A, the second upper arm detection layer 224A, or the third upper arm detection layer 234A. As shown in Fig. As shown in Fig. 18, in each of the switching elements 31 electrically bonded to the first forearm mounting layer 211B, the second forearm mounting layer 221B, or the third forearm mounting layer 231B, one end of the first detection wire 431 is connected to one of the paired first pads 311A. The other end of the first detection wire 431 is connected to the first forearm detection layer 214B, the second forearm detection layer 224B, or the third forearm detection layer 234B. In this way, the front surface electrodes 311 are electrically connected to the first detection layer 214, the second detection layer 224, or the third detection layer 234 via the first detection wires 431. For example, the first detection wires 431 are made of gold (Au).
[0069] As in Fig. 16 to 20 (including Fig. 18), the back surface electrode 312 is provided on the entirety of the back surface 31B. A drain current flows through the back surface electrode 312. The back surface electrode 312 is electrically bonded to one of the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231 via a first bonding layer 391. The first bonding layer 391 is electrically conductive. The first bonding layer 391 is disposed between the back surface electrode 312 and the first mounting layer 211, the second mounting layer 221, or the third mounting layer 231. For example, the first bonding layer 391 is made of lead-free solder composed mainly of tin. The first bonding layer 391 electrically connects the back surface electrodes 312 to one of the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231.
[0070] As in Fig. 15 and Fig. 18, the gate electrode 313 is provided on the front surface 31A. A gate voltage for driving each of the switching elements 31 is applied to the gate electrode 313. As shown in Fig. 15, in each of the switching elements 31 electrically bonded to the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, or the third upper arm mounting layer 231A, the gate electrode 313 is located near the paired second pads 311B of the front surface electrode 311. One end of the first gate wire 421, which is connected at its other end to the first upper arm gate layer 213A, the second upper arm gate layer 223A, or the third upper arm gate layer 233A, is connected to the gate electrode 313. As shown in Fig. As shown in Fig. 18, in each of the switching elements 31 electrically bonded to the first underarm mounting layer 211B, the second underarm mounting layer 221B, or the third underarm mounting layer 231B, the gate electrode 313 is located near the paired first pads 311A of the front surface electrode 311. One end of the first gate wire 421, which is connected at its other end to the first underarm gate layer 213B, the second underarm gate layer 223B, or the third underarm gate layer 233B, is connected to the gate electrode 313. In this way, the gate electrodes 313 are electrically connected to the first gate layer 213, the second gate layer 223, or the third gate layer 233 via the first gate wires 421. For example, the first gate wires 421 are made of gold.
[0071] As in Fig. As shown in Figures 15 to 20, the insulating film 314 is provided on the front surface 31A. The insulating film 314 is electrically insulating. When viewed in the thickness direction z, the insulating film 314 surrounds the front surface electrode 311. The insulating film 314 can be formed by laminating a silicon dioxide layer (SiO2 layer), a silicon nitride layer (Si3N4), and a polybenzoxazole layer (PBO layer) on the front surface 31A in the order mentioned. For the insulating film 314, a polyimide layer can be used instead of the polybenzoxazole layer. Fig. 15 to 20, the length from the edge 314A of the insulating film 314 to the front surface electrode 311, when viewed in the thickness direction z, is indicated as a gap Gp in each of the switching elements 31. The gap Gp represents a length along the first direction x1 or the second direction x2. The edge 314A is rectangular when viewed in the thickness direction z (square in the semiconductor device A10). When viewed in the thickness direction z, the ratio of the length of the gap Gp to the length of one side of the edge 314 (the shorter side when the edge 314 is rectangular) is set to 5% to 25%. The longer the gap, the higher the dielectric breakdown voltage of the switching element 31.
[0072] As in Fig. 3, the protection elements 32 are semiconductor elements electrically bonded to each of the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231 and aligned therewith in the second direction x2. The protection elements 32 are rectangular when viewed in the thickness direction z. The protection elements 32 are arranged such that they are electrically connected to the switching elements 31, respectively. The protection elements 32 are electrically connected to both the front surface electrodes 311 and the back surface electrodes 312 of the switching elements 31. Therefore, each of the switching elements 31 and a corresponding one of the protection elements 32 form a parallel circuit. For example, the protection elements 32 are Schottky barrier diodes fabricated using a semiconductor material composed mainly of silicon carbide.In the semiconductor device A10, the protective elements 32 have a thickness of 400 µm or less, or preferably 150 µm or less. The breakdown voltage of the protective elements 32 is 1200 V or more.
[0073] As in Fig. As shown in Figures 15 to 20, each of the protection elements 32 has a front surface 32A, a back surface 32B, a side surface 32C, an anode electrode 321, a cathode electrode 322, and an insulating film 323. The front surface 32A corresponds to the "second element front surface" as set forth in the appended claims of the present disclosure. The front surface 32A faces in the same direction as the front surface 111 of the substrate 11 along the thickness direction z. The back surface 32B faces in the opposite direction to the front surface 32A. The protection elements 32 are electrically bonded to the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231, with the back surfaces 32B facing the front surface 111. The side surface 32C is connected to both the front surface 32A and the rear surface 32B.The side surface 32C comprises a plurality of sections (four sections in the semiconductor device A10), each pointing in the first direction x1 or the second direction x2.
[0074] As in Fig. As shown in Figures 15 to 20, the anode electrode 321 is provided on the front surface 32A. The anode electrode 321 is electrically connected to the front surface electrode 311 of the switching element 31 with which that protection element 32 is associated.
[0075] As in Fig. 16 and Fig. As shown in Figure 19, the cathode electrode 322 is provided on the entire back surface 32B. The cathode electrode 322 is electrically bonded to one of the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231 via a second bonding layer 392. The second bonding layer 392 is electrically conductive. The second bonding layer 392 is disposed between the cathode electrode 322 and the first mounting layer 211, the second mounting layer 221, or the third mounting layer 231. The second bonding layer 392 is made of the same material as that for the first bonding layer 391. In the second bonding layer 392, the cathode electrode 322 is electrically connected via the first mounting layer 211, the second mounting layer 221, or the third mounting layer 231 to the back surface electrode 312 of the switching element 31 with which the protective element 32 of that cathode electrode 322 is associated.
[0076] As in Fig. 16 and Fig. 19, the insulating film 323 is provided on the front surface 32A. The insulating film 323 is electrically insulating. As shown in Fig. 15 and Fig. As shown in Figure 18, the insulating film 323 surrounds the anode electrode 321 when viewed in the thickness direction z. The insulating film 323 can be formed by laminating a silicon dioxide layer, a silicon nitride layer, and a polybenzoxazole layer on the front surface 31A in the order mentioned. A polyimide layer can be used for the insulating film 323 instead of the polybenzoxazole layer.
[0077] As in Fig. 3 and Fig. As shown in Figure 8, thermistor 33 is an element that is electrically bonded to thermistor mounting layer 215. For example, thermistor 33 is an NTC (negative temperature coefficient) thermistor. An NTC thermistor has the property that its resistance decreases with increasing temperature. Thermistor 33 is used as a temperature detection sensor of semiconductor device A10.
[0078] As in Fig. 15 to 17, wires 41 are electrically connected to the front surface electrodes 311 of the switching elements 31 and the first forearm mounting layer 211B, the second forearm mounting layer 221B, or the third forearm mounting layer 231B. As shown in Fig. As shown in Figures 18 to 20, wires 41 are electrically connected to the front surface electrodes 311 of the switching elements 31 and the first electrically conductive layer 212, the second electrically conductive layer 222, or the third electrically conductive layer 232. For example, the wires 41 are made of aluminum. The wires 41 have a larger diameter than the first gate wires 421 and the first detection wires 431.
[0079] As in Fig. 15 to 17, in the switching elements 31 that are electrically bonded to the first upper arm mounting layer 211A, wires 41 are connected to the front surface electrodes 311 and the first forearm mounting layer 211B. As shown in Fig. As shown in FIGS. 18 to 20, in the switching elements 31 electrically bonded to the first forearm mounting layer 211B, wires 41 are connected to the front surface electrodes 311 and the first electrically conductive layer 212. Therefore, the front surface electrodes 311 of the switching elements 31 electrically bonded to the first forearm mounting layer 211B are electrically connected to the first forearm mounting layer 211B or the first electrically conductive layer 212.
[0080] As in Fig. 15 to 17, in the switching elements 31 electrically bonded to the second upper arm mounting layer 221A, wires 41 are connected to the front surface electrodes 311 and the second lower arm mounting layer 221B. As shown in Fig. As shown in FIGS. 18 to 20, in the switching elements 31 electrically bonded to the second forearm mounting layer 221B, wires 41 are connected to the front surface electrodes 311 and the second electrically conductive layer 222. Therefore, the front surface electrodes 311 of the switching elements 31 electrically bonded to the second forearm mounting layer 221B are electrically connected to the second forearm mounting layer 221B or the second electrically conductive layer 222.
[0081] As in Fig. 15 to 17, in the switching elements 31, which are electrically bonded to the third upper arm mounting layer 231A, wires are connected to the front surface electrodes 311 and the third lower arm mounting layer 231B. As shown in Fig. As shown in FIGS. 18 to 20, in the switching elements 31 electrically bonded to the third forearm mounting layer 231B, wires 41 are connected to the front surface electrodes 311 and the third electrically conductive layer 232. Therefore, the front surface electrodes 311 of the switching elements 31 electrically bonded to the third forearm mounting layer 231B are electrically connected to the third forearm mounting layer 231B or the third electrically conductive layer 232.
[0082] As in Fig. As shown in Figures 15 to 29, the wires 41 extend in the first direction x1. Each of the wires 41 has a first bonding portion 411. The first bonding portions 411 are held in contact with the front surface electrodes 311 of the switching elements 31. The wires 41 of each of the switching elements 31 include a pair of inner wires 41A and a pair of outer wires 41B. The paired inner wires 41A are flanked by the paired outer wires 41B in the second direction x2.
[0083] With reference to Fig. 15 to 17, a description will be given below of the configuration of the wires 41 for each of the switching elements 31 electrically bonded to the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, or the third upper arm mounting layer 231A. As shown in Fig. 17, the first bonding portions 411 of the paired inner wires 41A are held in contact with the paired first pads 311A of the front surface electrode 311. As shown in Fig. 16, the first bonding portions 411 of the paired outer wires 41B are held in contact with both the paired first pads 311A and the paired second pads 311B of the front surface electrode 311. As shown in Fig. 15 and Fig. As shown in Fig. 16, each of the first bonding portions 411 of the paired outer wires 41B includes a first connecting portion 411A, a second connecting portion 411B, and a linking portion 411C. The first connecting portion 411A is held in contact with a first pad 311A. The second connecting portion 411B is held in contact with a second pad 311B. The linking portion 411C is disposed between the first connecting portion 411A and the second connecting portion 411B in the first direction x1. The linking portion 411C protrudes in the same direction as the front surface 31A of the switching element 31 faces along the thickness direction z.
[0084] As in Fig. 15 and Fig. As shown in Figure 16, each of the wires 41 for each of the switching elements 31 electrically bonded to the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, or the third upper arm mounting layer 231A has a second bonding portion 412. The second bonding portion 412 is held in contact with the anode electrode 321 of the protective element 32. Therefore, the anode electrodes 321 of the protective elements 32 electrically bonded to the first upper arm mounting layer 211A are electrically connected to both the front surface electrodes 311 of the corresponding switching elements 31 and the first lower arm mounting layer 211B. The anode electrodes 321 of the protection elements 32, which are electrically bonded to the second upper arm mounting layer 221A, are electrically connected to both the front surface electrodes 311 of the corresponding switching elements 31 and the second lower arm mounting layer 221B.The anode electrodes 321 of the protection elements 32, which are electrically bonded to the third upper arm mounting layer 231A, are electrically connected to both the front surface electrodes 311 of the corresponding switching elements 31 and the third lower arm mounting layer 231B.
[0085] With reference to Fig. 18 to 20, a description will be given below of the configuration of the wires 41 for each of the switching elements 31 electrically bonded to the first lower arm mounting layer 211B, the second lower arm mounting layer 221B, or the third lower arm mounting layer 231B. As shown in Fig. 20, the first bonding portions 411 of the paired inner wires 41A are held in contact with the paired first pads 311A of the front surface electrode 311. As shown in Fig. 19, the first bonding portions 411 of the paired outer wires 41B are held in contact with both the paired first pads 311A and the paired second pads 311B of the front surface electrode 311. As shown in Fig. 18 and Fig. As shown in Fig. 19, each of the first bonding portions 411 of the paired outer wires 41B includes a first connecting portion 411A, a second connecting portion 411B, and a linking portion 411C. The first connecting portion 411A is held in contact with a first pad 311A. The second connecting portion 411B is held in contact with a second pad 311B. The linking portion 411C is disposed between the first connecting portion 411A and the second connecting portion 411B in the first direction x1. The linking portion 411C protrudes in the same direction as the front surface 31A of the switching elements 31 faces along the thickness direction z.
[0086] As in Fig. 18 and Fig. As shown in Figure 19, each of the paired outer wires 41B for each of the switching elements 31 electrically bonded to the first underarm mounting layer 211B, the second underarm mounting layer 221B, or the third underarm mounting layer 231B has a second bonding portion 412. The second bonding portion 412 is held in contact with the anode electrode 321 of the protection element 32. Therefore, the anode electrodes 321 of the protection elements 32 electrically bonded to the first underarm mounting layer 211B are electrically connected to both the front surface electrodes 311 of the corresponding switching elements 31 and the first electrically conductive layer 212. The anode electrodes 321 of the protection elements 32, which are electrically bonded to the second forearm mounting layer 221B, are electrically connected to both the front surface electrodes 311 of the corresponding switching elements 31 and the second electrically conductive layer 222.The anode electrodes 321 of the protection elements 32, which are electrically bonded to the third forearm mounting layer 231B, are electrically connected to both the front surface electrodes 311 of the corresponding switching elements 31 and the third electrically conductive layer 232.
[0087] As in Fig. As shown in FIG. 18, a pair of auxiliary wires 46 are connected to the anode electrode 321 of each of the protection elements 32, which are electrically bonded to the first underarm mounting layer 211B, the second underarm mounting layer 221B, or the third underarm mounting layer 231B. The auxiliary wires 46 are connected at the other ends thereof to paired second pads 311B of the front surface electrode 311 of the switching element 31 with which the protection element 32 is associated. The auxiliary wires 46 are arranged, in the second direction x2, between paired outer wires 41B. The auxiliary wires 46 are made of the same material as that of the wires 41. The diameters of the auxiliary wires 46 are the same as those of the wires 41.
[0088] As in Fig. As shown in FIGS. 15 to 20, the moisture-proof layer 51 covers the side surface 31C of the switching elements 31. An electrically insulating material having high thermal shock resistance and lower moisture permeability than the sealing resin 52 (silicone gel in semiconductor device A10) is selected as the material for the moisture-proof layer 51. Polyimide and silicone gel are selected as such an electrically insulating material for the moisture-proof layer 51. The ratio of the weight of polyimide to silicone gel in the moisture-proof layer 51 is 1.5:1 to 7.0:1. That is, in the moisture-proof layer 51, the weight of polyimide is greater than that of silicone gel. In the moisture-proof layer 51, polyimide molecules and silicone gel molecules are mixed. Preferably, polyimide molecules and silicone gel molecules are evenly distributed in the moisture-proof layer 51.This effectively prevents cracking of the moisture-resistant layer 51 due to temperature fluctuations, so that the moisture-resistant layer 51 maintains the function of preventing moisture penetration. Although the moisture-resistant layer 51 consisting only of polyimide and silicone gel is explained for the semiconductor device A10, other materials may be added to these materials to form the moisture-resistant layer 51. Although a mixture of polyimide and silicone gel is selected as the material for the moisture-resistant layer 51 in the semiconductor device A10, other materials having low moisture permeability may also be selected. For example, the moisture-resistant layer 51 may be made of a mixture of polybenzoxazole and silicone gel.
[0089] An example of a method for forming the moisture-resistant layer 51 of the semiconductor device A10 is described below. A liquefied resin material containing polyimide, silicone gel, and a solvent is prepared. Note that the solvent is highly volatile. Then, the resin material is dropped onto the mounting layer (the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231) using a dispenser. As a result, the resin material spreads onto the side surfaces 31C of the switching elements 31, so that the side surfaces 31C are covered with the resin material. Finally, the resin material is heat-cured to obtain the moisture-resistant layer 51. During this process, the solvent evaporates. With this method, the moisture-resistant layer 51 covering the side surfaces 31C of the switching elements 31 is easily formed.
[0090] As in Fig. As shown in Figures 15 to 17, the moisture-resistant layer 51 is held in contact with one of the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, or the third upper arm mounting layer 231A, and with the side surface 31C of at least one of the switching elements 31. In the thickness direction z, the moisture-resistant layer 51 extends such that it is spanned between the side surface 31A and the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, or the third upper arm mounting layer 231A, thereby extending over the bonding layer 39 and the back surface electrode 312.
[0091] As in Fig. As shown in FIGS. 18 to 20, the moisture-resistant layer 51 is held in contact with the first underarm mounting layer 211B, the second underarm mounting layer 221B, or the third underarm mounting layer 231B, and with the side surface 31C of switching elements 31. In the thickness direction z, the moisture-resistant layer 51 extends so as to be sandwiched between the side surface 31A and the first underarm mounting layer 211B, the second underarm mounting layer 221B, or the third underarm mounting layer 231B, thereby overlying the bonding layer 39 and the back surface electrode 312.
[0092] Therefore, the moisture-resistant layer 51 is held in contact with the first mounting layer 211, the second mounting layer 221, or the third mounting layer 231 and at least one of the side surfaces 31C. In the thickness direction, the moisture-resistant layer 51 extends such that it is sandwiched between the first mounting layer 211, the second mounting layer 221, or the third mounting layer 231 and the side surface 31C.
[0093] As in Fig. 15, Fig. 16, Fig. 18 and Fig. As shown in Figure 19, the moisture-proof layer 51 integrally covers the side surface 31C of a switching element 31 and the side surface 32C of the protective element 32 paired with that switching element 31 (the protective element 32 connected in antiparallel with the switching element 31). In the example shown in these figures, the moisture-proof layer 51 is provided corresponding to the pairs of switching elements 31 and protective elements 32. That is, the moisture-proof layer 51 is divided into a plurality of sections so that each section covers a pair of the side surface 31C of a switching element 31 and the side surface 32C of a protective element 32. In contrast to this embodiment, the moisture-resistant layer 51 may be designed to integrally cover the side surfaces 31 of a plurality of switching elements 31 on each of the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231.
[0094] As in Fig. 11 and Fig. 12, the sealing resin 52 is housed in an area surrounded by the housing 70 and the heat sink 61. As shown in Fig. 16, Fig. 17, Fig. 19 and Fig. As shown in Figure 20, the sealing resin 52 covers both the circuit elements 31 and the moisture-resistant layer 51. The sealing resin 52 also covers the protective elements 32. It is preferred that the sealing resin 52 be an electrically insulating resin with excellent heat resistance and adhesion. For example, the sealing resin 52 is silicone gel composed primarily of thermosetting organopolysiloxane. The sealing resin 52 is exposed to the atmosphere.
[0095] As in Fig. 11 and Fig. 12, the heat sink 61 is bonded to the back surface 112 of the substrate 11. In the semiconductor device A10, the heat sink 61 is bonded to each of the back surface 112 of the first substrate 11A, the back surface 112 of the second substrate 11B, and the back surface 112 of the third substrate 11C via a heat transfer layer 62 and a substrate bonding layer 69 (both described below). For example, the heat sink 61 is made of a metal plate, such as a copper plate. The surface of the metal plate may be plated with nickel. As shown in Fig. As shown in FIGS. 7 to 9, the heat sink 61 is provided with a plurality of support holes 611 at its four corners when viewed in the thickness direction z. Each of the support holes 611 penetrates the heat sink 61 in the thickness direction z. The support holes 611 are used to support the heat sink 61, which is bonded to the substrate 11, on the package 70.
[0096] As in Fig. 11 and Fig. As shown in Figure 12, the heat transfer layer 62 is disposed on the back surface 112 of the substrate 11. The heat transfer layer 62 is made of a metallic material, such as copper foil. The heat transfer layer 62 transfers the heat generated by the operation of the switching elements 31 to the heat sink 61.
[0097] The substrate bonding layer 69 is a bonding material arranged between the heat sink 61 and the heat transfer layer 62, as shown in Fig. 11 and Fig. 12. In semiconductor device A10, substrate bonding layer 69 is made of lead-free solder, which is primarily composed of tin. Substrate bonding layer 59 bonds heat sink 61 to substrate 11.
[0098] The housing 70 is an electrically insulating element which surrounds the substrate 11 when viewed in the thickness direction z, as shown in Fig. 3. The housing 70 is in the shape of a frame. The housing 70 is made of an electrically insulating resin with excellent heat resistance, such as PPS (polyphenylene sulfide). The housing 70 includes a pair of side walls 71, a pair of terminal seats 72, mounting portions 73, a supply terminal base 74, and an output terminal base 75.
[0099] As in Fig. 2, Fig. 3, Fig. 5 and Fig. 6, the paired sidewalls 71 are spaced apart from each other in the first direction x1 and have the shape of a groove. Each of the sidewalls 71 is arranged along both the second direction x2 and the thickness direction z, and one end, in the thickness direction z, of each sidewall is held in contact with the heat sink 61. Opposite ends of each sidewall 71 in the second direction x2 are connected to the paired terminal seats 72. In one of the sidewalls 71, the first gate terminal 27A, the first detection terminal 281A, the supply current detection terminal 282, and the paired thermistor terminals 29 are arranged. In the other sidewall 71, the second gate terminal 27A and the second detection terminal 281B are arranged. As shown in Fig. 8 to 10, the ends of these terminals, which are located near the substrate 11 in the thickness direction z, are supported on the side walls 71.
[0100] As in Fig. 3, Fig. 8 and Fig. As shown in Figure 9, the paired terminal seats 72 are spaced apart from each other in the second direction x2. Each of the terminal seats 72 is arranged along the second direction x2. To one of the terminal seats 72, the supply terminal base 74, which protrudes outward in the second direction x2, is connected, and a part of the supply terminal 24 is supported on the terminal seat 72. To the other of the terminal seats 72, the output terminal base 75, which protrudes outward in the second direction x2, is connected, and a part of the output terminal 25 is supported on the terminal seat 72.
[0101] As in Fig. 2, Fig. 8 and Fig. As shown in Fig. 9, the fixing portions 73 are provided at four corners of the housing 70 when viewed in the thickness direction z. Each of the fixing portions 73 is provided with a fixing hole 731 penetrating the fixing portion 73 in the thickness direction z. The positions of the fixing holes 731 correspond to the support holes 611 provided in the heat sink 61. The heat sink 61 is supported on the housing 70 by inserting fixing members such as pins into the fixing holes 731 and the support holes 611.
[0102] As in Fig. 2, Fig. 5 and Fig. As shown in Figure 8, the supply terminal base 74, together with the terminal seat 72 connected thereto, supports the supply terminal 24. The supply terminal base 74 includes a first terminal base 741 and a second terminal base 742. The first terminal base 741 and the second terminal base 742 are spaced apart from each other in the first direction x1. A part of the first supply terminal 24A is supported on the first terminal base 741, and the supported part is exposed to the outside of the semiconductor device A10. A part of the second supply terminal 24B is supported on the second terminal base 742, and the supported part is exposed to the outside of the semiconductor device A10. As shown in Fig. 8 and Fig. As shown in Figure 13, a nut 743 is disposed in each of the first terminal base 741 and the second terminal base 742. Each nut 743 corresponds in the thickness direction z to the coupling hole 241 provided in the first supply port 24A or the second supply port 24B. The fastening member, such as a bolt, inserted into the coupling hole 241 is threadably engaged with a nut 743.
[0103] As in Fig. 2, Fig. 6 and Fig. As shown in Figure 9, the output terminal base 75, together with the terminal seat 72 connected thereto, supports the output terminal 25. The output terminal base 75 includes a first terminal base 751 and a second terminal base 752. The first terminal base 751 and the second terminal base 752 are spaced apart from each other in the first direction x1. A part of the first output terminal 25A is supported on the first terminal base 751, and the supported part is exposed to the outside of the semiconductor device A10. A part of the second output terminal 25B is supported on the second terminal base 752, and the supported part is exposed to the outside of the semiconductor device A10. As shown in Fig. 9 and Fig. As shown in Figure 14, a nut 753 is disposed in each of the first terminal base 751 and the second terminal base 752. Each nut 753 corresponds in the thickness direction z to the coupling hole 251 provided in the first output port 25A or the second output port 25B. The fastening member, such as a bolt, inserted into the coupling hole 251 is threadably engaged with a nut 753.
[0104] As in Fig. 2, Fig. 11 and Fig. As shown in Figure 12, the top plate 79 encloses the interior of the semiconductor device A10, which is defined by the heat sink 61 and the housing 70. The top plate 79 is supported on the paired sidewalls 71 of the housing 70 such that it faces the front surface 111 of the substrate 11 and is spaced apart from the front surface 111 in the thickness direction z. The top plate 79 is made of an electrically insulating resin.
[0105] Next, the circuit configuration in the semiconductor device A10 will be described with reference to Fig. 21 described.
[0106] As in Fig. 21, two circuits, namely an upper arm circuit 81 and a lower arm circuit 82, are formed in the semiconductor device A10. The upper arm circuit 81 may be formed of the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, the third upper arm mounting layer 231A, and the switching elements 31 and the protection elements 32 electrically bonded to these mounting layers. The switching elements 31 and the protection elements 32 electrically bonded to these mounting layers are connected in parallel between the first power supply terminal 24A and the output terminal 25. The gate electrodes 313 of the switching elements 31 in the upper arm circuit 81 are connected in parallel to the first gate terminal 27A. The switching elements 31 in the upper arm circuit 81 are simultaneously driven by applying a gate voltage to the first gate terminal 27A using a driver circuit such asa gate driver arranged outside the semiconductor component A10.
[0107] The front surface electrodes 311 of the switching elements 31 in the upper arm circuit 81 are connected in parallel to the first detection terminal 281A. The source current flowing through the switching elements 31 in the upper arm circuit 81 is input to a control circuit arranged outside the semiconductor device A10 via the first detection terminal 281A.
[0108] In the upper arm circuit 81, the voltage applied to the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, and the third upper arm mounting layer 231A through the first supply terminal 24A and the second supply terminal 24B is input to the control circuit arranged outside the semiconductor device A10 via the supply current detection terminal 282.
[0109] The lower arm circuit 82 may be formed of the first lower arm mounting layer 211B, the second lower arm mounting layer 221B, the third lower arm mounting layer 231B, and the switching elements 31 electrically bonded to the mounting layers, and the protection elements 32 are connected in parallel between the output terminal 25 and the second power supply terminal 24B. The gate electrodes 313 of the switching elements 31 in the lower arm circuit 82 are connected in parallel to the second gate terminal 27B. The switching elements 31 in the lower arm circuit 82 are simultaneously operated by applying a gate voltage to the second gate terminal 27B using a driving circuit such as a gate driver arranged outside the semiconductor device A10.
[0110] The front surface electrodes 311 of the switching elements 31 in the lower arm circuit 82 are connected in parallel to the second detection terminal 281B. The source current flowing through the switching elements 31 in the lower arm circuit 82 is input to a control circuit arranged outside the semiconductor device A10 via the second detection terminal 281B.
[0111] AC voltages of various frequencies are output from the output terminal 25 by applying a DC power supply to the first power supply terminal 24A and the second power supply terminal 24B and operating the switching elements 31 in the upper arm circuit 81 and the lower arm circuit 82. The AC voltage output from the output terminal 25 is supplied to a power supply destination, such as a motor.
[0112] The advantages of the A10 semiconductor device are described below.
[0113] In the configuration of the semiconductor device A10, the moisture-resistant layer 51 is held in contact with both the mounting layer (the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231) and the side surface 31C of the switching elements 31. In the thickness direction z, the moisture-resistant layer 51 extends such that it is sandwiched between the mounting layer and the side surface 31C. When moisture penetrates into the sealing resin 52 due to the effect of high temperature and high humidity, a leakage current Lc is likely to be generated from the front surface electrode 311 of the switching element 31, as shown in Fig. 22. At the switching element 31, the leakage current Lc tries to flow along the front surface of the insulating film 314 and the side surface 31C. The provision of the moisture-proof layer 51 causes the path of the leakage current Lc to become longer, thereby making it difficult for the leakage current LC to flow. Since the leakage current Lc is thus prevented from reaching the mounting layer, failure of the switching element 31 due to the flow of the leakage current Lc is prevented. Therefore, the semiconductor device A10 operates stably under high-temperature and high-humidity conditions. When the switching element 31 or the protective element 32 has a comparatively small thickness of 150 μm or less, the path of the leakage current Lc becomes relatively short. When a voltage of 1200 V or more is applied to such a semiconductor device, the leakage current Lc flows relatively easily.The provision of the moisture-resistant layer 51 is particularly effective for such a comparatively thin switching element 31.
[0114] In the Fig. In Comparative Example B10 shown in Fig. 23, which does not include a moisture-resistant layer 51, the leakage current Lc is conducted to the mounting layer (the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231) along the side surface 31C of the switching element 31. This causes a short circuit between the front surface electrode 311 and the back surface electrode 312 of the switching element 31, resulting in failure of the switching element 31.
[0115] It is preferred that the moisture-resistant layer 51 contains polyimide. Polyimide is an electrically insulating material that is resistant to cyclic temperature fluctuations and is not easily affected by moisture. Therefore, by containing polyimide, the moisture-resistant layer 51 reliably prevents the leakage current Lc from flowing along the side surface 31C, even under high-temperature and high-humidity conditions, as shown in Fig. 22 shown.
[0116] It is preferable that the moisture-resistant layer 51 contains silicone gel in addition to polyimide. Such a moisture-resistant layer 51 has a lower elastic modulus compared to a moisture-resistant layer 51 made of polyimide alone. Therefore, the moisture-resistant layer 51 easily follows the thermal stress of the switching element 31 during use of the semiconductor device A10. This reduces the shear stress acting on the switching element 31.
[0117] Furthermore, the inclusion of polyimide and silicone gel in the moisture-resistant layer 51 improves the resistance of the moisture-resistant layer 51 to cyclic temperature changes. A semiconductor device A10 with a moisture-resistant layer 51 made solely of polyimide was subjected to a thermal cycling test in a range of -40 to 125°C. As a result, the semiconductor device A10 became defective after approximately 20 cycles. Presumably, a crack formed in the moisture-resistant layer 51, and moisture penetrating through the crack caused the failure. A semiconductor device A10 with a moisture-resistant layer 51 made of polyimide and silicone gel was subjected to the same thermal cycling test, and the semiconductor device A10 remained intact even after 1,000 cycles.This is because the elastic modulus of the moisture-proof layer 51 is lower than that of the moisture-proof layer 51 made of polyimide alone, and therefore, the shear stress acting on the moisture-proof layer 51 due to thermal expansion or shrinkage is reduced. Therefore, it is preferable that the moisture-proof layer 51 contains polyimide and silicone gel.
[0118] The semiconductor device A10 includes wires 41 connected to the front surface electrodes 311 of the switching elements 31, and the wires 41 extend in the first direction x1. Therefore, the moisture-resistant layer 51 covering the side surface 31C of the switching element 31 can be formed so as not to be obstructed by the wires 41.
[0119] The first bonding portion 411 of each of the paired outer wires 41B includes the first connecting portion 411A held in contact with the first pad 411A, the second connecting portion 411B held in contact with the second pad 411B, and the linking portion 411C disposed between the first connecting portion 41A and the second connecting portion 411B. The linking portion 411C protrudes in the same direction as the front surface 31A of the switching element 31 along the thickness direction z. As shown in Fig. 16 and Fig. 19, it is preferable that the height H of the linking portion 411C in the thickness direction z from the front surface of the front surface electrode 311 of the switching element 31 to the top surface C of the linking portion 411C is not less than three times the diameter of the wires 41. For example, when the diameter of the wires 41 is 300 μm, it is preferable that the height H of the linking portion 411C be 900 μm or more. With such a configuration, the linking portion 411C functions as an elastic member capable of elastically deforming in the first direction x1 to reduce the shear stress acting on the first bonding portion 411A and the second bonding portion 411B. Therefore, peeling of the first bonding portion 411 from the front surface electrode 311 due to shear stress is prevented.In the semiconductor device A10, the diameter of the wires 41 is 400 µm, and the height of the interconnection portion 411C is 1600 µm. Note that when the height of the interconnection portion 411C in the semiconductor device A10 is 800 µm, at least one of the first interconnection portion 411A or the second interconnection portion 411B may be peeled off in the ΔTj power cycling test described below.
[0120] The semiconductor device A10 has the heat sink 61 bonded to the back surface 112 of the substrate 11. Therefore, the heat generated at the switching elements 31 is efficiently dissipated to the outside of the semiconductor device A10. In this case, it is preferred that the substrate 11 be made of a ceramic with excellent thermal conductivity (e.g., aluminum nitride).
[0121] Fig. 24 to 50 show semiconductor devices A11 to A15, which are modifications of the semiconductor device A10. [First variation]
[0122] A semiconductor device A11 according to a first modification of the semiconductor device A10 is described with reference to Fig. 24 and Fig. 25. The semiconductor device A11 is an example in which the contact area of the moisture-resistant layer 51 with the switching element 31 is smaller than that in the above semiconductor device A10. It should be noted that Fig. 24 is a cross-sectional view drawn along the same plane as Fig. 16. Fig. 25 is a cross-sectional view drawn along the same plane as Fig. 19.
[0123] As in Fig. 24 and Fig. 25, the moisture-resistant layer 51 covers a portion of the side surface 31C of the switching element 31.
[0124] The advantages of the semiconductor device A11 are described below.
[0125] In the configuration of the semiconductor device A11, the moisture-resistant layer 51 is held in contact with both the mounting layer (the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231) and the side surface 31C of the switching elements 31. In the thickness direction z, the moisture-resistant layer 51 extends so that it is sandwiched between the mounting layer and the side surface 31C. Therefore, the semiconductor device A11 also operates stably under high-temperature and high-humidity conditions. [Second variation]
[0126] A semiconductor device A12 according to a second modification of the semiconductor device A10 is described with reference to Fig. 26 to 31. The semiconductor device A12 is an example in which the contact area of the moisture-resistant layer 51 with the switching element 31 is larger than that in the above semiconductor device A10.
[0127] As in Fig. As shown in Figures 26 to 31, the moisture-resistant layer 51 of the switching element 31 is held in contact with both the side surface 31C and the insulating film 314. The moisture-resistant layer 51 spans the edge 314A of the insulating film 314 when viewed in the thickness direction z.
[0128] The advantages of the A12 semiconductor device are described below.
[0129] In the configuration of the semiconductor device A12, the moisture-resistant layer 51 is held in contact with both the mounting layer (the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231) and the side surface 31C of the switching elements 31. In the thickness direction z, the moisture-resistant layer 51 extends so that it is sandwiched between the mounting layer and the side surface 31C. Therefore, the semiconductor device A12 also operates stably under high-temperature and high-humidity conditions.
[0130] At the switching element 31 of the semiconductor device A12, the moisture-resistant layer 51 is held in contact with both the side surface 31C and the insulating film 314. The moisture-resistant layer 51 spans the edge 314A of the insulating film 314 when viewed in the thickness direction z. Such a configuration causes the Fig. 22 becomes longer than that in semiconductor device A10, making the flow of leakage current Lc more difficult compared to semiconductor device A10. Furthermore, since the moisture-proof layer 51 covers the insulating film 314, the insulating film 314 is protected from external influences. [Third variation]
[0131] A semiconductor device A13 according to a third modification of the semiconductor device A10 is described with reference to Fig. 32 to 37. The semiconductor device A13 is an example in which the contact area of the moisture-resistant layer 51 with the switching element 31 is larger than that in the above semiconductor device A12.
[0132] As in Fig. 32 to 37, on the switching element 31, the moisture-resistant layer 51 is held in contact with both the side surface 31C and the insulating film 314. The moisture-resistant layer 51 spans the edge 314A of the insulating film 314 when viewed in the thickness direction z. Furthermore, the moisture-resistant layer 51 is held in contact with at least a portion of the front surface electrode 311.
[0133] The advantages of the A13 semiconductor device are described below.
[0134] In the configuration of the semiconductor device A13, the moisture-resistant layer 51 is held in contact with both the mounting layer (the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231) and the side surface 31C of the switching elements 31. In the thickness direction z, the moisture-resistant layer 51 extends so that it is sandwiched between the mounting layer and the side surface 31C. Therefore, the semiconductor device A13 also operates stably under high-temperature and high-humidity conditions.
[0135] At the switching element 31 of the semiconductor device A13, the moisture-resistant layer 51 is held in contact with both the side surface 31C and the insulation film 314, and is also held in contact with at least a portion of the front surface electrode 311. As shown in Fig. 32 and Fig. As shown in Figure 35, when viewed in the thickness direction z, the moisture-proof layer 51 surrounds the front surface electrode 311 while overlapping a portion of the front surface electrode 311. This configuration improves the dielectric breakdown voltage of the side surface 31C compared with that in the semiconductor device A12, thereby making the flow of the leakage current Lc more difficult compared with the semiconductor device A12. Furthermore, since the moisture-proof layer 51 covers the insulating film 314, the insulating film 314 is protected from external influences. [Fourth variation]
[0136] A semiconductor device A14 according to a fourth modification of the semiconductor device A10 is described with reference to Fig. 38 to 43. The semiconductor device A14 is an example in which the contact area of the moisture-resistant layer 51 with the switching element 31 is larger than that in the above semiconductor device A13.
[0137] As in Fig. 38 to 43, on the switching element 31, the moisture-proof layer 51 is held in contact with both the side surface 31C and the insulating film 314. The moisture-proof layer 51 spans the edge 314A of the insulating film 314 when viewed in the thickness direction z. Furthermore, the moisture-proof layer 51 is held in contact with the front surface electrode 311 and at least a part of the first bonding portions 411 of the wires 41. Therefore, the switching elements 31 are entirely covered with the moisture-proof layer 51. However, the first bonding portions 411 are not entirely covered with the moisture-proof layer 51, and the upper ends of the first bonding portions 411 are exposed from the moisture-proof layer 51. That is, the thickness of the moisture-proof layer 51 covering the front surface 31A of the switching element 31 is smaller than the diameter of the wires 41.
[0138] As in Fig. 38, Fig. 39, Fig. 41 and Fig. 42, the moisture-resistant layer 51 covers the entire front surface of the protective element 32 associated with the switching element 31. However, the second bonding portions 412 of the wires 41 are not completely covered with the moisture-resistant layer 51, and the upper ends of the second bonding portions 411 are exposed from the moisture-resistant layer 51. That is, the thickness of the moisture-resistant layer 51 covering the front surface 32A of the protective element 32 is smaller than the diameter of the wires 41.
[0139] An example of a method for forming the moisture-resistant layer 51 of the semiconductor device A14 will be described below. A liquefied resin material containing polyimide, silicone gel, and a solvent is prepared. Note that the solvent is highly volatile. After the switching elements 31 and the protection elements 32 are electrically connected to the mounting layer on which these elements are mounted (the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231), the resin material is then dropped onto respective upper surfaces of a switching element 31 and a protection element 32 using a dispenser.Since the resin material has fluidity, it spreads over the entire upper surface of the switching element 31, including the front surface electrode 311, the gate electrode 313, and the insulating film 314, and further spreads from the side surface 31C of the switching element 31 to the mounting layer. Similarly, at the protective element 32, the entire front surface of the protective element 32 is covered with the resin material. Therefore, the entire front surface of the switching element 31 is covered with the resin material. Due to the surface tension of the resin material, the thickness of the resin material on the upper surface of the switching element 31 becomes generally uniform. Finally, the resin material is heat-cured to obtain the moisture-proof layer 51. During this process, the solvent evaporates.By this method, the moisture-proof layer 51 covering the switching element 31 and the protective element 32 is easily formed.
[0140] The advantages of the A14 semiconductor device are described below.
[0141] In the configuration of the semiconductor device A14, the moisture-resistant layer 51 is held in contact with both the mounting layer (the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231) and the side surface 31C of the switching elements 31. In the thickness direction z, the moisture-resistant layer 51 extends so that it is sandwiched between the mounting layer and the side surface 31C. Therefore, the semiconductor device A14 also operates stably under high-temperature and high-humidity conditions.
[0142] At each of the switching elements 31, the moisture-resistant layer 51 is held in contact with both the side surface 31C and the insulating film 314. The moisture-resistant layer 51 is also held in contact with the front surface electrode 311 and at least a part of the first bonding portions 411 of the wires 41. Since the entirety of the switching element 31 is covered with the moisture-resistant layer 51 in this way, moisture penetrating into the sealing resin 52 is prevented from reaching the front surface of the switching element 31. Therefore, dielectric breakdown of the switching elements 31, which is caused by the Fig. 22, which is caused by exposure to moisture, is effectively prevented. Furthermore, since the moisture-resistant layer 51 covers the insulating film 314, the insulating film 314 is protected from external influences.
[0143] On each of the switching elements 31, the paired outer wires 41B, each of which has the connecting portion 411C of the bonding portion 411 projecting in the thickness direction z, are arranged on opposite sides of the paired inner wires 41A in the second direction x2. Therefore, the resin material for forming the moisture-resistant layer 51 can be dropped from above the front surface 31A of the switching element 31 without disturbing the connecting portion 411C. As shown in Fig. 38, in the semiconductor device A14, the interconnection portions 411C are provided only in the first bonding portions 411 of the paired outer wires 41B. As another example, it may be considered to provide the interconnection portions 411C not only in the first bonding portions 411 of the paired outer wires 41B but also in the first bonding portions 411 of the paired inner wires 41A. However, with such a configuration, two adjacent interconnection portions 411C are arranged close to each other, causing the dropping of the resin material for forming the moisture-resistant layer 51 onto the switching element 31 to become difficult. Furthermore, when the resin material is dropped onto the switching element 31, the resin material may rise to the top of the interconnection portion 411C.In such a case, since the elastic modulus of the moisture-resistant layer 51 is comparatively high, heat generated by the switching elements 31 exerts a large shear stress on the connecting portions 411C. This may result in the detachment of the first connecting portions 411A and the second connecting portions 411B of the first bonding portions 411 from the front surface electrode 311 of the switching element 31. Therefore, in view of the reliability of the semiconductor device A14, it is preferable that a larger distance be secured between two adjacent connecting portions 411A in the second direction x2.
[0144] The moisture-proof layer 51 also covers the entirety of the protective member 32 associated with the switching element 31 covered by the moisture-proof layer. Therefore, the protective member 32 is effectively protected from external influences. On the other hand, the first bonding portions 411 are not completely covered with the moisture-proof layer 51, and the upper ends of the first bonding portions 411 are exposed from the moisture-proof layer 51. That is, the thickness of the moisture-proof layer 51 covering the front surface 31A of the switching element 31 is smaller than the diameter of the wires 41. With this configuration, compared with the configuration in which the first bonding portions 411 are completely covered with the moisture-proof layer 51, excessive shear stress is less likely to act on the first bonding portions 411.Therefore, peeling of the first bonding portions 411 from the front surface electrode 311 of the switching element 31 is prevented, which improves the reliability of the semiconductor device A14.
[0145] Next, with reference to Fig. 50, a description of an advantageous thickness of the moisture-resistant layer 51 in the semiconductor device A14 is given. Fig. Figure 50 shows the results of an H3TRB test and a ΔTj power cycling test with varying thicknesses of the moisture-resistant layer 51 of the semiconductor device A14. Fig. The thickness of the moisture-proof layer 51 shown in FIG. 50 is the thickness at the corner of the insulating film 314 (i.e., the portion connected to both the edge 314A and the side surface 31C) of a switching element 31. Before performing the H3TRB test, the semiconductor device A14 was subjected to a cyclic temperature change from -40 to 125°C. The number of temperature cycles was 300. In the H3TRB test, the semiconductor device A14 was operated at a DC voltage of 1360 V, as explained below. In the ΔTj power cycling test, the temperature ΔTj of the first bonding layer 391 for electrically bonding the switching elements 31 to the mounting layer (the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231) was set to 100°C. Considering this, the range of temperature cycles in the ΔTj power cycling test was from 50 to 150 °C.
[0146] The left vertical axis in Fig. 50 is intended to indicate the service life of the semiconductor device A14 in the H3TRB test. The "service life" means the time from the start of the test to the time at which dielectric breakdown is detected in at least one of the switching elements 31 of the semiconductor device A14. The right vertical axis in Fig. 50 is intended to indicate the number of temperature cycles undertaken in the ΔTj power cycle before the bonding portion 411 of a wire 41 connected to the front surface electrode 311 of a switching element 31 was detached from the front surface electrode 311 (hereinafter referred to as “ΔTj power cycle”). The desired number of temperature cycles (or the standard value of the ΔTj power cycle used in Fig. 50 is displayed) is 15000. The horizontal axis in Fig. 50 represents the thickness of the moisture-resistant layer 51.
[0147] As in Fig. 50, the service life of the semiconductor device A14 increases sharply when the thickness of the moisture-resistant layer 51 exceeds 10 μm. This indicates that the resistance of the switching element 31 to breakdown due to moisture penetration (or reliability related to moisture absorption) improves with increasing thickness of the moisture-resistant layer 51. On the other hand, the ΔTj duty cycle gradually decreases with increasing thickness of the moisture-resistant layer 51. This indicates that increasing the thickness of the moisture-resistant layer 51 results in an increased risk of detachment of the first bonding portion 411 of the wire 41 from the front surface electrode 311 of the switching element 31 or detachment of the second bonding portion 412 of the wire 41 from the anode electrode 321 of the protective element 32.These test results showed that a preferred thickness of the moisture-resistant layer 51 is in the range of 40 to 200 µm. A more preferred range of the thickness of the moisture-resistant layer 51 may be from 50 to 100 µm. Experiments have confirmed that the thickness of the moisture-resistant layer 51 on the upper surface of the switching element 31 is 1.2 times the thickness of the moisture-resistant layer 51 at the corners. Accordingly, the preferred thickness of the moisture-resistant layer 51 on the upper surface of the switching element 31 is from 48 to 240 µm, and more preferably from 60 to 120 µm.
[0148] Fig. Figure 51 shows the results (unit: h) of the H3TRB test performed on the semiconductor device A14 and a Fig. 23, which does not include the moisture-resistant layer 51. As described above, a semiconductor device determined to be acceptable in the H3TRB test (the device life is 1000 hours or more) is expected to operate stably under high-temperature and high-humidity conditions. In the H3TRB test, when the rated voltage is 1700 V, the DC voltage for driving the semiconductor device A14 and the comparative example B10 is set to 1360 V (80% of the rated voltage). As a result of the H3TRB test performed based on this DC voltage, it was determined that the life of the semiconductor device A14 was 1000 hours or more, which is acceptable. Therefore, the semiconductor device A14 is expected to operate stably under high-temperature and high-humidity conditions.On the other hand, the service life of Comparative Example B10 was 10 to 500 hours, which is unacceptable. Comparative Example B10 is considered inferior to the semiconductor device A14 in terms of its ability to operate stably under high-temperature and high-humidity conditions.
[0149] As in Fig. 51, the reduction rate of the insulation resistance (unit: %) of the sealing resin 52 during the H3TRB test was 20% in the semiconductor device A14 and 84% in the comparative example B10. Probably, the Fig. 51 shown reduction rates of the insulation resistance of the sealing resin 52 are obtained, since the moisture-resistant layer 51 prevents the Fig. 22 flows along the side surfaces 31C of the switching element even when moisture penetrates into the sealing resin 52 due to a high-temperature and high-humidity environment. [Fifth Variation]
[0150] A semiconductor device A15 according to a fifth modification of the semiconductor device A10 is described with reference to Fig. 44 to 49. The semiconductor device A15 is an example in which the thickness of the moisture-resistant layer 51 on the upper surface of a switching element 31 is greater than that in the above semiconductor device A14.
[0151] As in Fig. 44 to 49, on the switching elements 31, the moisture-resistant layer 51 covers both the switching elements 31 and the first bonding portions 411 of the wires 41.
[0152] As in Fig. 44, Fig. 45, Fig. 47 and Fig. 48, the moisture-resistant layer 51 covers the entirety of the front surface of the protective member 32 associated with the switching element 31 and the second bonding portions 412 of the wires 41 connected to the anode electrode 321 of the protective member 32.
[0153] The advantages of the A15 semiconductor device are described below.
[0154] In the configuration of semiconductor device A15, moisture-resistant layer 51 is held in contact with both the mounting layer (first mounting layer 211, second mounting layer 221, and third mounting layer 231) and the side surface 31C of switching elements 31. In the thickness direction z, moisture-resistant layer 51 extends so as to be sandwiched between the mounting layer and the side surface 31C. Therefore, semiconductor device A15 also operates stably under high-temperature and high-humidity conditions.
[0155] At the switching element 31, the moisture-resistant layer covers both the switching element 31 and the first bonding portions 411 of the wires 41. Since the entirety of the switching element 31 is covered with the moisture-resistant layer 51 in this way, moisture penetrating into the sealing resin 52 is prevented from reaching the front surface 31A of the switching element 31. Therefore, dielectric breakdown of the switching elements 31, which is caused by the Fig. 22, which is caused by exposure to moisture, is effectively prevented. Furthermore, since the moisture-resistant layer 51 covers the insulating film 314, the insulating film 314 is protected from external influences. In semiconductor device A15, it is again preferable that the thickness of the moisture-resistant layer 51 on the upper surface of the switching element 31 be from 48 to 240 µm. [Second embodiment]
[0156] A semiconductor device A20 according to a second embodiment of the present disclosure is described with reference to Fig. 52 to 57. In these figures, the elements that are the same as or similar to those of the above semiconductor device A10 are denoted by the same reference numerals as those used for the above embodiment, and descriptions thereof are omitted.
[0157] The semiconductor device A20 differs from the above semiconductor device A10 in that it includes clips 47 instead of the wires 41.
[0158] As in Fig. 52 to 54, the clips 47 are electrically bonded to the front surface electrodes 311 of the switching elements 31 and the first forearm mounting layer 211B, the second forearm mounting layer 221B, or the third forearm mounting layer 231B. As shown in Fig. As shown in Figures 55 to 57, the clips 47 are electrically bonded to the front surface electrodes 311 of the switching elements 31 and the first electrically conductive layer 212, the second electrically conductive layer 222, or the third electrically conductive layer. The clips 47 are manufactured by bending a thin metal plate, such as a copper plate. As shown in Fig. 52 and Fig. 55, the clips 47 are each in the form of a strip which, when viewed in the thickness direction z, extends in the first direction x1. As shown in Fig. 53 and Fig. 56, the clips 47 have a hook-like shape when viewed in the second direction x2. As shown in Fig. 53 and Fig. 56, the clips 47 are electrically bonded to an object, such as the front surface electrode 311, using a clip bonding layer 49. The clip bonding layer 49 is electrically conductive. For example, the clip bonding layer 49 is made of lead-free solder composed mainly of tin. To use the clip bonding layer 49, a metallization layer made of nickel or gold, for example, is applied to the front surface of the front surface electrode 311. When the front surface electrode 311 is covered with the moisture-resistant layer 51, in the semiconductor device A20, the clip bonding layer 49 and the metallization layer are also covered with the moisture-resistant layer 51.
[0159] As in Fig. 52 to 54, in the switching elements 31 that are electrically bonded to the first upper arm mounting layer 211A, the clips 47 are electrically bonded to the front surface electrodes 311 and the first forearm mounting layer 211B. As shown in Fig. As shown in FIGS. 55 to 57, in the switching elements 31 electrically bonded to the first forearm mounting layer 211B, the clips 47 are electrically bonded to the front surface electrodes 311 and the first electrically conductive layer 212. Therefore, the front surface electrodes 311 of the switching elements 31 electrically bonded to the first forearm mounting layer 211B are electrically connected to the first forearm mounting layer 211B or the first electrically conductive layer 212.
[0160] As in Fig. 52 to 54, in the switching elements 31 that are electrically bonded to the second upper arm mounting layer 221A, the clips 47 are electrically bonded to the front surface electrodes 311 and the second lower arm mounting layer 221B. As shown in Fig. As shown in FIGS. 55 to 57, in the switching elements 31 electrically bonded to the second forearm mounting layer 221B, the clips 47 are electrically bonded to the front surface electrodes 311 and the second electrically conductive layer 222. Therefore, the front surface electrodes 311 of the switching elements 31 electrically bonded to the second forearm mounting layer 221B are electrically connected to the second forearm mounting layer 221B or the second electrically conductive layer 222.
[0161] As in Fig. 52 to 54, in the switching elements 31 that are electrically bonded to the third upper arm mounting layer 231A, the clips 47 are electrically bonded to the front surface electrodes 311 and the third lower arm mounting layer 231B. As shown in Fig. As shown in FIGS. 55 to 57, in the switching elements 31 electrically bonded to the third forearm mounting layer 231B, the clips 47 are electrically bonded to the front surface electrodes 311 and the third electrically conductive layer 232. Therefore, the front surface electrodes 311 of the switching elements 31 electrically bonded to the third forearm mounting layer 231B are electrically connected to the third forearm mounting layer 231B or the third electrically conductive layer 232.
[0162] With reference to Fig. 52 and Fig. 53, a description will be given below of the configuration of the clips 47 for each of the switching elements 31 electrically bonded to the first upper arm mounting layer 211A, the second upper arm mounting layer 221A, or the third upper arm mounting layer 231A. As shown in Fig. 53, each clip 47 is also electrically bonded to the anode electrode 321 of the protection element 32 associated with the switching element 31 using the clip bonding layer 49. Therefore, the anode electrode 321 of the protection element 32, which is electrically bonded to the first upper arm mounting layer 211A, is electrically connected to both the front surface electrode 311 of the corresponding switching element 31 and the first lower arm mounting layer 211B. The anode electrode 321 of the protection element 32, which is electrically bonded to the second upper arm mounting layer 221A, is electrically connected to both the front surface electrode 311 of the corresponding switching element 31 and the second lower arm mounting layer 221B.In addition, the anode electrode 321 of the protective element 32, which is electrically bonded to the third upper arm mounting layer 231A, is electrically connected to both the front surface electrode 311 of the corresponding switching element 31 and the third lower arm mounting layer 231B.
[0163] As in Fig. 52 and Fig. 53, each of the clips 47 has an opening 471 penetrating in the thickness direction z. The opening 471 is located, in the first direction x1, between the front surface electrode 311 of the switching element 31 and the anode electrode 321 of the protective element 32. When viewed in the thickness direction z, the edge 314A of the insulating film 314 of the switching element 31 is visible through the opening 471. When the clips 47 are electrically bonded to the front surface electrodes 311 of the switching elements 31, most of the switching elements 31 are covered with the clips 47. By forming an opening 471 in each clip 47 at a position overlapping the switching element 31 when viewed in the thickness direction, the resin material for forming the moisture-proof layer 51 can be dropped under the clip 47. Therefore, the resin material can be dropped evenly over the entirety of the switching element 31.Although the semiconductor device A20 is described as having an opening 471 in each clip 47, a cutout penetrating in the thickness direction z may be formed instead of the opening 471 in each clip 47 at a position overlapping the switching element 31 when viewed in the thickness direction z.
[0164] With reference to Fig. 55 and Fig. 56, a description will be given below of the configuration of the clips 47 for each of the switching elements 31 electrically bonded to the first forearm mounting layer 211B, the second forearm mounting layer 221B, or the third forearm mounting layer 231B. As shown in Fig. 56, each clip 47 is also electrically bonded to the anode electrode 321 of the protection element 32 associated with the switching element 31 using the clip bonding layer 49. Therefore, the anode electrode 321 of the protection element 32, which is electrically bonded to the first underarm mounting layer 211B, is electrically connected to both the front surface electrode 311 of the corresponding switching element 31 and the first electrically conductive layer 212. The anode electrode 321 of the protection element 32, which is electrically bonded to the second underarm mounting layer 221B, is electrically connected to both the front surface electrode 311 of the corresponding switching element 31 and the second electrically conductive layer 222.Furthermore, the anode electrode 321 of the protective element 32, which is electrically bonded to the third forearm mounting layer 231B, is electrically connected to both the front surface electrode 311 of the corresponding switching element 31 and the third electrically conductive layer 232. Since the clip 47 is electrically bonded to the anode electrode 321, the electrical connections shown in FIG. Fig. 18, the paired additional wires 46 in the semiconductor device A20 are not connected to the anode electrode 321.
[0165] As in Fig. 55 and Fig. As shown in Figure 56, each of the clips 47 has a pair of openings 471 penetrating in the thickness direction z. The paired openings 471 are arranged on opposite sides of the front surface electrode 311 of the switching element 31 in the first direction x1. When viewed in the thickness direction z, the edge 314A of the insulating film 314 of the switching element 31 is visible through the paired openings 471.
[0166] The advantages of the A20 semiconductor device are described below.
[0167] In the configuration of the semiconductor device A20, the moisture-resistant layer 51 is held in contact with the side surfaces 31A of the switching elements 31 as well as the first mounting layer 211, the second mounting layer 221, or the third mounting layer 231. In the thickness direction, the moisture-resistant layer 51 extends so that it is sandwiched between the first mounting layer 211, the second mounting layer 221, or the third mounting layer 231 and the side surfaces 31C. Therefore, the semiconductor device A20 also operates stably under high-temperature and high-humidity conditions.
[0168] The configuration of the moisture-resistant layer 51 of semiconductor device A20 is the same as that of semiconductor device A10. However, it should be noted that the configuration of the moisture-resistant layer 51 in semiconductor devices A11 to A15 can be used in semiconductor device A20.
[0169] The semiconductor device A20 has clips 47 instead of the wires 41. The cross-sectional area (the area in the cross section along the second direction x2) of the clip 47 is larger than that of the wires 41. Therefore, the electrical resistance of the clip 47 is lower than that of the wires 41. Therefore, the parasitic resistance of the semiconductor device A20 is lower than that of the semiconductor device A10, so that the power loss of the semiconductor device A20 is reduced compared to the semiconductor device A10.
[0170] Since the cross-sectional area of the clip 47 is larger than that of the wires 41, the clip 47 conducts more heat in the first direction x1 than the wires 41. Therefore, heat generated by the switching elements 31 is dissipated more efficiently. For example, on the first substrate 11A, it is likely that the heat generated by the switching elements 31 is dissipated in the first upper arm mounting layer 211A, which has the Fig. 21. The clips 47 efficiently dissipate the heat collected in the first upper arm mounting layer 211A to the first forearm mounting layer 211A and the first electrically conductive layer 212.
[0171] The number of switching elements electrically bonded to each of the first mounting layer 211, the second mounting layer 221, and the third mounting layer 231 can be appropriately adjusted according to the required power conversion. The first mounting layer 211, the second mounting layer 221, and the third mounting layer 231 represent examples of a "mounting layer" as set forth in the appended claims of the present disclosure. The number of sections constituting the "mounting layer" is not limited to six as in the present disclosure and can be appropriately adjusted.
[0172] The above embodiments show the example in which the moisture-proof layer 51 covers the switching elements 31 and the protection elements 32 connected in antiparallel to the switching elements 31. However, in a semiconductor device that does not use the protection elements 32 but uses only the switching elements 31 (the configuration that does not use an external flyback diode), the moisture-proof layer 51 may cover the switching elements 31. Furthermore, the present disclosure is applicable not only to switching elements but also to rectifier elements. For example, the present disclosure is applicable to a semiconductor device including a plurality of Schottky barrier diodes. In this case, the configuration, such as the material, thickness, or formation area, of the moisture-proof layer 51 is the same as that of the above embodiments.
[0173] In the above embodiments, the semiconductor device includes, as an example, a substrate 11 on which electrically conductive elements (the mounting layer and the electrically conductive layer) fabricated on a thin metal film and the switching elements 31 electrically bonded to the electrically conductive elements are disposed. The present disclosure is not limited to such an example and is also applicable to a resin package type semiconductor device including a lead frame on which elements such as switching elements or rectifier elements are electrically bonded and resin-molded. Since such a semiconductor device also has a risk of moisture penetration through the sealing resin, covering the entire surfaces or side surfaces of the switching elements or rectifier elements with the moisture-resistant layer according to the present disclosure provides the same advantages.Note that the connection structure by wire bonding using the wires 41 in the semiconductor device A10, or the connection structure using a thin metal plate or clips 47 in the semiconductor device A20 is also applicable to the resin package type semiconductor device.
[0174] The present disclosure includes, in addition to the embodiments set forth in the appended claims, at least the embodiments related to the following clauses. Clause 1.
[0175] Semiconductor device comprising: a first electrically conductive layer, a second electrically conductive layer spaced from the first electrically conductive layer, a semiconductor element comprising: a semiconductor layer, a front surface electrode provided on an upper surface of the semiconductor layer, and a back surface electrode arranged on a lower surface of the semiconductor layer, wherein the semiconductor element is mounted on the first electrically conductive layer, wherein the back surface electrode is electrically connected to the first electrically conductive layer, a connection structure electrically connected to the front surface electrode and the second electrically conductive layer, a first insulation layer covering at least one side surface of the semiconductor element, and a second insulation layer covering the first insulation layer, The first insulation layer is made of a material that has lower moisture permeability than the second insulation layer. The first insulation layer acts as a barrier film to prevent moisture penetration. Clause 2.
[0176] A semiconductor device according to clause 1, wherein the first insulation layer covers an entirety of the semiconductor device. Clause 3.
[0177] A semiconductor device according to clause 1, wherein the connection structure comprises a connection portion held in contact with the front surface electrode, and the first insulation layer covers an entirety of the semiconductor element except for the connecting portion. Clause 4.
[0178] A semiconductor device according to clause 1, wherein a thickness of the first insulation layer is from 40 to 200 µm at a corner located between a top surface and the side surface of the semiconductor element, and the thickness of the first insulation layer is from 48 to 240 µm on the upper surface of the semiconductor element. Clause 5.
[0179] A semiconductor device according to clause 4, wherein the thickness of the first insulating layer is from 50 to 100 µm at the corner located between the top surface and the side surface of the semiconductor element, and the thickness of the first insulation layer is 60 to 120 µm on the upper surface of the semiconductor element. Clause 6.
[0180] A semiconductor device according to clause 1, wherein the interconnection structure comprises an interconnection structure using a wire, and a thickness of the first insulation layer on an upper surface of the semiconductor element is smaller than a diameter of the wire. Clause 7.
[0181] A semiconductor device according to clause 6, wherein the wire comprises a connecting portion held in contact with the front surface electrode, and The thickness of the first insulating layer on the upper surface of the semiconductor element is smaller than the height of the connecting portion (a distance from a front surface of the front surface electrode to a top surface of the connecting portion). That is, the top surface of the connecting portion is exposed from the first insulating layer. The connecting portion is crushed with a wedge tool during a bonding process, and the height of the connecting portion is smaller than the diameter of the wire. Clause 8.
[0182] A semiconductor device according to clause 1, wherein a thickness of the semiconductor layer is 400 µm or less. Clause 9.
[0183] A semiconductor device according to clause 8, wherein a thickness of the semiconductor layer is 150 µm or less. Clause 10.
[0184] The semiconductor device according to clause 1, wherein the semiconductor device further comprises a voltage-resistant structure including an insulating layer covering an upper surface of the semiconductor layer and surrounding an edge of the front surface electrode, and the first insulating layer covering the voltage-resistant structure. In the voltage-resistant structure, an oxide film or a nitride film is formed on the semiconductor layer, and a layer such as a polyimide layer or a polybenzoxazole layer is formed thereon as the insulating layer. Clause 11.
[0185] A semiconductor device according to clause 1, wherein the first insulating layer contains a synthetic resin which is polyimide or polybenzoxazole. Clause 12.
[0186] A semiconductor device according to clause 11, wherein the first insulating layer comprises silicone gel. Clause 13.
[0187] A semiconductor device according to clause 12, wherein the synthetic resin and the silicone gel are uniformly distributed in the first insulating layer. Clause 14.
[0188] A semiconductor device according to clause 12 or 13, wherein a weight proportion of the synthetic resin in the first insulating layer is greater than that of the silicone gel. Clause 15.
[0189] A semiconductor device according to clause 14, wherein the ratio of the weight fraction of the synthetic resin to the silicone gel in the first insulating layer is from 1.5:1 to 7.0:1. Clause 16.
[0190] The semiconductor device according to clause 1, wherein the interconnection structure comprises an interconnection structure using a wire and an interconnection structure using a thin metal plate. Clause 17.
[0191] A semiconductor device according to clause 1, wherein the semiconductor layer is made of a semiconductor material composed mainly of silicon carbide. Clause 18.
[0192] A semiconductor device according to clause 17, wherein the semiconductor device comprises a MOSFET or a Schottky barrier diode. Clause 19.
[0193] A semiconductor device according to clause 1, wherein a breakdown voltage of the protective element is 1200 V or more. Clause 20.
[0194] A semiconductor device according to clause 1, wherein the first electrically conductive layer and the second electrically conductive layer are made of a lead frame, and the second insulation layer comprises a resin casing sealing the first electrically conductive layer, the second electrically conductive layer, the semiconductor element and the interconnection structure. Clause 21.
[0195] A semiconductor device according to clause 1, wherein the first electrically conductive layer and the second electrically conductive layer comprise a metal layer arranged on an insulating substrate, and The second insulating layer comprises a resin casing that seals the insulating substrate, the first electrically conductive layer, the second electrically conductive layer, the semiconductor element, and the interconnection structure. The sealing resin contains silicone gel. Clause 22.
[0196] A semiconductor device according to clause 1, wherein the second insulating layer has a front surface exposed to outside air (atmosphere). Clause 23.
[0197] A method of manufacturing a semiconductor device according to any one of clauses 1 to 22, the method comprising the following steps: Preparing a synthetic resin material containing: a material having a lower moisture permeability than a material forming the second insulation layer or a precursor thereof, and a volatile solvent, electrically connecting the back surface electrode to the first electrically conductive layer, dropping the resin material onto an upper surface of the semiconductor element to cover the semiconductor element with the resin material, and Heat-curing the resin material, wherein the semiconductor element is covered with the resin material, thereby forming the first insulating layer. Before the step of heat-curing the resin material, the resin material does not need to function as the first insulating layer. It is only required that the resin material function as the first insulating layer after heat-curing. For example, polyimide is dissolved in the solvent in a precursor state, and after heat-curing, it becomes polyimide through "imidization," thereby functioning as the first insulating layer. Clause 24.
[0198] A method of manufacturing the semiconductor device according to clause 23, further comprising the step of connecting the connection structure to the front surface electrode and the second electrically conductive layer before the step of covering the semiconductor element with the resin material.
Claims
[1] Semiconductor device (A10), comprising: a substrate (11) comprising a front surface (111) facing in a thickness direction (z), a mounting layer (211) which is electrically conductive and arranged on the front surface (111), the mounting layer comprising an upper arm mounting layer (211A) and a lower arm mounting layer (211B) which are spaced apart from each other in a first direction (x) which is perpendicular to the thickness direction (z), an electrically conductive layer (212) arranged on the front surface (111) of the substrate (11), a plurality of switching elements (31), each of which has a first element front surface (31A) facing in a same direction as the front surface (111) along the thickness direction, a first element back surface (31B) facing in a direction opposite to the first element front surface (31A), and a first element side surface (31C) connected to both the first element front surface (31A) and the first element back surface (31B), wherein each switching element (31) is electrically bonded to the mounting layer (211), the first element back surface (31B) facing the front surface (111), each switching element (31) having a front surface electrode (311) on the element front surface (31A) and a back surface electrode (312) on the element back surface (31B), a wire (41) being connected to the front surface electrode (311), and the back surface electrode (312) is electrically bonded to the mounting layer (211); Protective elements (32) which are electrically bonded to the upper arm mounting layer (211A) and the forearm mounting layer (211B) and are respectively electrically connected to the front surface electrodes (311), a plurality of wires (41), each of which is connected to the front surface electrode (311) and one of the forearm mounting layer (211B) or the electrically conductive layer (212), a moisture-resistant layer (51) covering the first element side surface (31C) of at least one switching element (31), and a sealing resin (52) covering the switching elements (31) and the moisture-resistant layer (51), wherein the moisture-resistant layer (51) is made of an electrically insulating material having a lower moisture permeability than the material from which the sealing resin (52) is made, wherein the moisture-resistant layer (51) is held in contact with the mounting layer (211) and the first element side surface (31C) so that it is stretched between the mounting layer (211) and the first element side surface (31C) in the thickness direction (z), wherein each of the protective elements (32) comprises a second element front surface (32A) facing in a same direction as the front surface (111) along the thickness direction (z), a side surface (32C) and an anode electrode (321) provided on the second element front surface (32A), and wherein at least one of the wires (41) connected to the front surface electrode (311) is connected to the anode electrode (321), and wherein the moisture-resistant layer (51) integrally covers the first element side surface (31C) of a switching element (31) and the side surface (32C) of the protective element (32) connected to that switching element (31). [2] A semiconductor device according to claim 1, wherein the sealing resin (52) comprises silicone gel. [3] A semiconductor device according to claim 2, wherein the moisture-resistant layer (51) comprises polyimide. [4] A semiconductor device according to claim 3, wherein the moisture-resistant layer (51) comprises silicone gel in addition to polyimide. [5] Semiconductor component according to claim 3 or 4, wherein the switching elements (31) are electrically bonded to the upper arm mounting layer (211A) and the lower arm mounting layer (211B), and on the upper arm mounting layer (211A) and the lower arm mounting layer (211B) the switching elements (31) are aligned in a second direction (x2) perpendicular to the thickness direction and the first direction (x1). [6] A semiconductor device according to claim 5, wherein each of the switching elements (31) comprises an insulating film (314) provided on the first element front surface (31A), the insulating film (314) surrounding the front surface electrode (311) when viewed in the thickness direction, and the moisture-resistant layer (51) is held in contact with the first element side surface (31C) and the insulating film (314) and extends over an edge of the insulating film (314) when viewed in the thickness direction (z). [7] A semiconductor device according to claim 6, wherein the moisture-resistant layer (51) is kept in contact with at least a part of the front surface electrode (311). [8] A semiconductor device according to claim 7, further comprising: the electrically conductive layer (212) arranged on the front surface (111) and arranged in the first direction (x1) on the other side of the forearm mounting layer (211B) than the upper arm mounting layer (211A), and wherein each of the wires (41) comprises a first bonding portion (411) held in contact with the front surface electrode (311), and the moisture-resistant layer (51) is kept in contact with at least a part of the first bonding portion (411). [9] A semiconductor device according to claim 8, wherein the wires (41) extend in the first direction (x1). [10] The semiconductor device according to claim 9, wherein each of the front surface electrodes (311) comprises a pair of first pads (311A) spaced apart from each other in the second direction and a pair of second pads (311B) spaced apart from each other in the second direction, the paired second pads (311B) being arranged on the other side of the paired first pads (311A) in the first direction (x1) than the underarm mounting layer (211B) or the electrically conductive layer (212), in each of the switching elements (31), the wires (41) comprise a pair of inner wires (41A) having the first bonding portions (411) held in contact with the first pads (311A), and a pair of outer wires (41B) having the first bonding portions (411) held in contact with both the first pads (311A) and the second pads (311B), and the paired outer wires (41B) are arranged on opposite sides of the paired inner wires (41A) in the second direction (x2). [11] The semiconductor device according to claim 10, wherein each of the first bonding portions (411) of the paired outer wires (41B) comprises a first connecting portion (411A) held in contact with the first pad (311A), a second connecting portion (411B) held in contact with the second pad (311B), and a linking portion (411C) arranged in the first direction between the first connecting portion (411A) and the second connecting portion (411B), and the linking portion (411C) protrudes in a same direction in which the first element front surface (31A) faces along the thickness direction (z). [12] A semiconductor device according to any one of claims 8 to 11, wherein the substrate (11) comprises a first substrate (11A) and a second substrate (11B) spaced apart from each other in the second direction (x2), on the front surface (111) of each of the first substrate (11A) and the second substrate (11B), a portion of the upper arm mounting layer (211A), a portion of the lower arm mounting layer (211B) and a portion of the electrically conductive layer (212) are arranged, and the semiconductor component further comprises a first supply terminal (24A) electrically connected to the portion of the upper arm mounting layer (211A) arranged on the first substrate (11A), a second supply terminal (24B) electrically connected to the portion of the electrically conductive layer (212) arranged on the first substrate (11A), and an output terminal (25) electrically connected to the portion of the lower arm mounting layer (211B) arranged on the second substrate (11B). [13] The semiconductor device of claim 12, further comprising an electrically conductive connecting element (261) comprising a first part (261A), a second part (261B) and a third part (261C) and extending in the second direction (x2), wherein the portion of the upper arm mounting layer (211A) arranged on the first substrate (11A) and the portion of the upper arm mounting layer (211A) arranged on the second substrate (11B) are electrically connected to each other via the first part (261A), the portion of the forearm mounting layer (211B) arranged on the first substrate (11A) and the portion of the forearm mounting layer (211B) arranged on the second substrate (11B) are electrically connected to each other via the second part (261B), and the portion of the electrically conductive layer (212) arranged on the first substrate (11A) and the portion of the electrically conductive layer (212) arranged on the second substrate (11B) are electrically connected to one another via the third part (261C). [14] A semiconductor device according to claim 13, wherein each of the first substrate (11A) and the second substrate (11B) comprises a back surface facing in an opposite direction along the thickness direction (z) than the front surface (111), and wherein the semiconductor device further comprises a heat sink (61) bonded to both the back surface of the first substrate (11A) and the back surface of the second substrate (11B). [15] A semiconductor device according to claim 14, further comprising a frame-like housing (70) surrounding the substrate (11) when viewed in the thickness direction (z), wherein the first supply terminal (24A), the second supply terminal (24B), the output terminal (25) and the heat sink (61) are supported on the housing (70), and the sealing resin (52) is housed in an area surrounded by the housing (70) and the heat sink (61).
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