Semiconductor module

Abstract

A semiconductor module (10) includes a circuit substrate (17), a plurality of semiconductor switching elements (24Up, 24Un, 24Vp, 24Vn, 24Wp, 24Wn) of an inverter circuit adapted to be connected to the circuit substrate, a plurality of bus bars, and a molding member (11) integrally sealing the circuit substrate, the plurality of semiconductor switching elements, and the plurality of bus bars, the plurality of semiconductor switching elements being arranged in a planar direction of the circuit substrate, the plurality of bus bars including first bus bars (26U, 26V, 26W) connecting the plurality of semiconductor switching elements included in each bridge branch of the inverter circuit in series with each other, and a second bus bar (27) connected to a high potential side or a low potential side of the bridge branch and arranged between the first bus bars and the circuit substrate, at least a portion of the first bus bars and the second bus bar overlapping each other when viewed in a direction of viewing the circuit substrate in plan view, and a direction of current flowing in the first bus bars being opposite to a direction of current flowing in the second bus bar.

Description

[0001] Citation of relevant applications

[0002] This application is based on Japanese Patent Application No. 2021-130016, filed on August 6, 2021, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a semiconductor module comprising multiple semiconductor elements. Background Technology

[0004] Patent Document 1 describes a semiconductor module in which an insulating substrate, a printed circuit board, and multiple semiconductor elements are integrally sealed within a sealing resin. The multiple semiconductor elements are disposed on the upper surface of the insulating substrate and the lower surface of the printed circuit board. The multiple semiconductor elements are bonded to the upper surface of a conductive layer disposed on the upper surface of the insulating substrate via a solder layer, and are also bonded to the lower surface of a conductive layer disposed on the lower surface of the printed circuit board via a solder layer. A through-hole extending vertically is provided in the printed circuit board, and signal electrodes of the multiple semiconductor elements are electrically connected to the printed circuit board through a conductive member disposed within the through-hole.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-153607 Summary of the Invention

[0008] In Patent Document 1, multiple conductive layers with different potentials are disposed adjacent to each other on the same plane between the printed circuit board and multiple semiconductor components. Therefore, when the current or potential within the semiconductor module changes drastically, magnetic noise or electrostatic noise may be generated, causing the printed circuit board to malfunction.

[0009] In view of the above, the purpose of this disclosure is to provide a technique for suppressing malfunctions of printed circuit boards caused by changes in current or potential within a semiconductor module.

[0010] This disclosure includes: a circuit board; a plurality of semiconductor switching elements suitable for an inverter circuit connected to the circuit board; a plurality of buses; and a molding compound that integrally seals the circuit board, the plurality of semiconductor switching elements, and the plurality of buses. In this semiconductor module, the plurality of semiconductor switching elements are arranged along the plane of the circuit board. The plurality of buses includes: a first bus that connects the plurality of semiconductor switching elements included in each bridge branch of the inverter circuit in series; and a second bus that is connected to the high-potential side or low-potential side of the bridge branch and is disposed between the first bus and the circuit board. When viewed from a top view of the circuit board, at least a portion of the first bus and the second bus overlap each other, and the direction of the current flowing in the first bus is opposite to the direction of the current flowing in the second bus.

[0011] In the semiconductor module disclosed herein, the first bus and the second bus overlap at least partially when viewed from above along the direction of the circuit board. Furthermore, since the current flows in opposite directions through the first and second buses, even if the current flowing through the first bus and the current flowing through the second bus changes drastically, changes in the magnetic field caused by the current changes can be suppressed at the overlapping portion. Therefore, in cases where the current or potential of each bus changes drastically due to the switching of the inverter circuit, the generation of magnetic noise can be suppressed. Additionally, the second bus functions as an electromagnetic shield, suppressing the influence of the magnetic field generated by current changes in the inverter circuit on the circuit board. As a result, malfunctions of the circuit board due to changes in current or potential within the semiconductor module can be suppressed. Attached Figure Description

[0012] The above-mentioned objects, other objects, features, and advantages of this disclosure will become clearer with reference to the accompanying drawings and the following detailed description. The drawings are described below.

[0013] Figure 1 This is a perspective view showing the appearance of the semiconductor module in the implementation method.

[0014] Figure 2 It is built into Figure 1 The inverter circuit in the semiconductor module shown.

[0015] Figure 3 It means from Figure 1 The diagram shows a top view of the semiconductor module after the molded parts have been removed.

[0016] Figure 4 It means from Figure 1 The image shows a 3D view of the semiconductor module after the molded parts have been removed.

[0017] Figure 5 yes Figure 4 VV-line sectional view.

[0018] Figure 6 yes Figure 4 Sectional view along line VI-VI.

[0019] Figure 7 yes Figure 4 Sectional view along line VII-VII.

[0020] Figure 8 It means from Figure 3 The diagram shows a top view of the state after the circuit board has been further removed.

[0021] Figure 9 It means from Figure 4 The image shown is a three-dimensional view of the state after the circuit board has been further removed.

[0022] Figure 10 yes Figure 8 XX-line sectional view.

[0023] Figure 11 It means from Figure 8 The diagram shows a top view of the state after the second busbar has been removed.

[0024] Figure 12 It means from Figure 9 The diagram shown is a three-dimensional representation of the state after further removal of the second busbar.

[0025] Figure 13 It means from Figure 10 The shown is a cross-sectional view of the state after the second busbar has been removed.

[0026] Figure 14 This is a schematic diagram showing a cross-section of a semiconductor module.

[0027] Figure 15 It is a diagram showing the current flowing through the first busbar and the current flowing through the second busbar.

[0028] Figure 16 This diagram illustrates the state of wireless communication between the wireless communication circuit included in the circuit board and an external circuit board.

[0029] Figure 17 This diagram shows the connection between the external terminals included in the circuit board and an external circuit board.

[0030] Figure 18 This is a diagram showing a semiconductor module with a low-shrinkage layer within a molded part. Detailed Implementation

[0031] like Figure 1 As shown, in semiconductor module 10, circuit board 17 and six semiconductor switching elements are integrally sealed within a resin molding 11. The six semiconductor switching elements are n-channel RC-IGBTs of identical structure and size; the semiconductor module 10 is composed of these six semiconductor switching elements. Figure 2 The inverter circuit shown.

[0032] The inverter circuit is a three-phase full-bridge circuit comprising three bridge branches consisting of two semiconductor switching elements connected in series. The upper arm switch SUP and lower arm switch SUB connected to terminal U 14U, the upper arm switch SVp and lower arm switch SVn connected to terminal V 14V, and the upper arm switch SWp and lower arm switch SWn connected to terminal W 14W are sealed within the molded part 11. The high-potential side of each bridge branch is connected to terminal P 12, and the low-potential side is connected to terminal N 13.

[0033] like Figure 1 As shown, the circuit board 17 has a portion protruding from the molded part 11, including P terminal 12, N terminal 13, U terminal 14U, V terminal 14V, W terminal 14W. By allowing a portion of the circuit board 17 to protrude from the molded part 11, heat dissipation is possible from the protruding portion. Furthermore, in the figures, the x and y directions are parallel to the planar directions of the semiconductor module 10 and the circuit board 17, and the z direction is the thickness direction of the semiconductor module 10 and the circuit board 17. P terminal 12 and N terminal 13 are arranged adjacent to each other in the x-direction and protrude in the positive y-axis direction relative to the molded part 11. The z-direction positions of P terminal 12 and N terminal 13 are approximately the same. U terminal 14U, V terminal 14V, and W terminal 14W protrude in the negative x-axis direction relative to the molded part 11, opposite to P terminal 12 and N terminal 13. U terminal 14U, V terminal 14V, and W terminal 14W are arranged adjacent to each other in this order from the negative x-axis side towards the positive x-axis side. The positions of U terminal 14U, V terminal 14V, and W terminal 14W in the z-direction are approximately the same.

[0034] Figures 3-7 Indicates from Figure 1 The semiconductor module 10 shown is in its state after the molding part 11 has been removed. Figures 3-7 As shown, the semiconductor module 10, integrally sealed within the molding compound 11, includes a circuit board 17, six semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn, and three first busbars 26U, 26V, and 26W. The semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn correspond to... Figure 2The upper arm switch SUP, lower arm switch SUB, upper arm switch SVp, lower arm switch SVn, upper arm switch SWp, and lower arm switch SWn are shown. A pair of semiconductor switching elements 24Up and 24Un, 24Vp and 24Vn, and 24Wp and 24Wn, contained in each bridge branch, are arranged along the y-axis. The semiconductor switching elements 24Up, 24Vp, and 24Wp corresponding to the upper arm switch are arranged on the positive y-axis side near the P terminal 12 and N terminal 13, while the semiconductor switching elements 24Un, 24Vn, and 24Wn corresponding to the lower arm switch are arranged on the negative y-axis side near the U terminal 14U, V terminal 14V, and W terminal 14W.

[0035] like Figure 3 , Figure 4 As shown, at the positions corresponding to the small signal pads of the semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn in the circuit board 17, through-holes 17Up, 17Un, 17Vp, 17Vn, 17Wp, and 17Wn are provided along the z-direction. Holes 17h are provided in the corners of the circuit board 17 when viewed from above.

[0036] Figures 8-10 This indicates the state after the circuit board 17 has been further removed from the semiconductor module 10. A second busbar 27 is positioned directly below the circuit board 17. For example... Figure 8 As shown, at the positions corresponding to the small signal pads of semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn in the second busbar 27, there are through holes 27Up, 27Un, 27Vp, 27Vn, 27Wp, and 27Wn that extend along the z-direction.

[0037] Through holes 17Up, 17Un, 17Vp, 17Vn, 17Wp, 17Wn and through holes 27Up, 27Un, 27Vp, 27Vn, 27Wp, 27Wn are located above the small signal pads of semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, 24Wn in the positive z-axis direction. By passing the bonding wires connected to the small signal pads of semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, 24Wn through each through hole, bonding wires can be connected on the upper surface (the surface on the positive z-axis side) of the circuit board 17.

[0038] The second generatrix 27, starting from the positive direction of the y-axis, sequentially includes a non-jointing portion 27p, a connecting portion 27m, a joining portion 27n, and an end portion 27e. The non-jointing portion 27p is located above the joining portion 27n, and the connecting portion 27m connects the non-jointing portion 27p to the joining portion 27n. The end portion 27e extends upwards from the joining portion 27n. Figure 5, Figure 8 As shown, the non-connected portion 27p and the connected portion 27n stand upright at their two ends in the x-direction along the positive z-axis. The second busbar 27 extends from the upper surface of the semiconductor switching elements 24Un, 24Vn, and 24Wn corresponding to the lower arm switch to the region of the N terminal 13 adjacent to the P terminal 12. When viewed from above along the direction of the circuit board 17, the second busbar 27 covers the multiple semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn contained in each bridge branch.

[0039] Figures 11-13 This indicates the state after further removing the second busbar 27 from the semiconductor module 10. First buses 26U, 26V, and 26W are positioned directly below the second busbar 27. When viewed from above along the direction of the circuit board 17, most of the first buses 26U, 26V, and 26W overlap with the second busbar 27. The first buses 26U, 26V, and 26W have a shape that extends along the y-axis and stands upright along the positive z-axis at their ends in the positive y-axis direction. Figure 8 As shown, in the portion other than the erected end, the first busbars 26U, 26V, and 26W are covered by the second busbar 27.

[0040] like Figures 5-7 As shown, the semiconductor module 10 includes, within the molded part 11, a first heat dissipation substrate 21p, 21n, an insulating substrate 18, and a second heat dissipation substrate 22p, 22Un, 22Vn, 22Vn stacked sequentially from the lower surface side (negative z-axis direction side). The first heat dissipation substrate 21p, 21n and the second heat dissipation substrate 22p, 22Un, 22Vn, 22Vn are conductive metal plates, more specifically, for example, flat plates made of materials such as copper.

[0041] Each semiconductor switching element 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn is arranged with the collector side of the p-type type facing down. Semiconductor switching elements 24Up, 24Vp, and 24Wp are bonded to the upper surface of the second heat sink substrate 22p via solder layers 23Up, 23Vp, and 23Wp. Semiconductor switching elements 24Un, 24Vn, and 24Wn are bonded to the upper surfaces of the second heat sink substrates 22Un, 22Vn, and 22Vn, respectively, via solder layers 23Un, 23Vn, and 23Wn. The P-terminal 12 is bonded to the positive y-axis end of the upper surface of the second heat sink substrate 22p via solder layer 33.

[0042] The first busbars 26U, 26V, and 26W are bonded to the upper surfaces of the semiconductor switching elements 24Up, 24Vp, and 24Wp via solder layers 25Up, 25Vp, and 25Wp. For example... Figure 11As shown, solder holes 26Uh, 26Vh, and 26Wh are provided in the first busbars 26U, 26V, and 26W. Figure 11 In the shown state, by allowing solder to flow from above into the solder holes 26Uh, 26Vh, and 26Wh, solder layers 25Up, 25Vp, and 25Wp can be easily formed. This allows for accurate configuration and bonding of the first busbars 26U, 26V, and 26W relative to the collectors of the semiconductor switching elements 24Up, 24Vp, and 24Wp. The solder holes 26Uh, 26Vh, and 26Wh can also be used for laser welding.

[0043] The first busbars 26U, 26V, and 26W are bonded to the upper surfaces of the second heat sink substrates 22Un, 22Vn, and 22Vn respectively via solder layer 31U at their negative y-axis ends. The U terminal 14U, V terminal 14V, and W terminal 14W are bonded to the upper surfaces of the second heat sink substrates 22Un, 22Vn, and 22Vn respectively via solder layer 32U. The first busbars 26U, 26V, and 26W, the semiconductor switching elements 24Un, 24Vn, and 24Wn, the U terminal 14U, the V terminal 14V, and the W terminal 14W are bonded to the upper surfaces of the second heat sink substrates 22Un, 22Vn, and 22Vn sequentially from the positive y-axis direction toward the negative y-axis direction.

[0044] The first buses 26U, 26V, and 26W electrically connect the upper surfaces of the semiconductor switching elements 24Up, 24Vp, and 24Wp (which are on the emitter side) to the upper surfaces of the second heat sink substrates 22Un, 22Vn, and 22Vn (which are on the collector side) of the same semiconductor switching elements 24Un, 24Vn, and 24Wn, respectively. Through the first buses 26U, 26V, and 26W, pairs of semiconductor switching elements 24Up and 24Un, 24Vp and 24Vn, and 24Wp and 24Wn, contained in each bridge branch, are connected in series. The first buses 26U, 26V, and 26W are O buses.

[0045] like Figures 5-7 As shown, above the bonding portions of the first buses 26U, 26V, and 26W that are bonded to the semiconductor switching elements 24Up, 24Vp, and 24Wp, a non-bonding portion 27p of the second bus 27 is disposed. The bonding portion 27n of the second bus 27 is bonded to the upper surfaces of the semiconductor switching elements 24Un, 24Vn, and 24Wn via solder layers 25Un, 25Vn, and 25Wn. The second bus 27 is connected to... Figure 2 The N bus (low-potential bus) of each bridge branch of the inverter circuit shown is connected to the low-potential side and is grounded.

[0046] like Figure 8 As shown, solder holes 27Uh, 27Vh, and 27Wh are provided in the joint 27n. Figure 8 In the shown state, by allowing solder to flow from above into the solder holes 27Uh, 27Vh, and 27Wh, solder layers 25Un, 25Vn, and 25Wn can be easily formed. This allows for accurate configuration and bonding of the second busbar 27 relative to the collectors of the semiconductor switching elements 24Un, 24Vn, and 24Wn. The solder holes 27Uh, 27Vh, and 27Wh can also be used for laser welding.

[0047] Figure 14 This is a schematic diagram showing a cross-section of the semiconductor module 10. Figure 14 Reference symbols in Figures 1 to 13 The reference symbols in the text represent the same structure in the numerical parts. For example... Figure 14 As shown, within the molding 11, the semiconductor module 10 has semiconductor switching elements 24p on the upper arm side and 24n on the lower arm side, forming the same bridge branch, arranged along the plane of the circuit board 17 and connected in series via a first busbar 26. The collector side of the upper arm semiconductor switching element 24p is electrically connected to the P terminal 12, and the lower arm semiconductor switching element 24n is electrically connected to the N terminal 13 via a second busbar 27. The second busbar 27 is disposed between the first busbar 26 and the circuit board 17, extending planarly to cover the structure disposed further below from the semiconductor switching element 24n to the N terminal 13. For example, when viewed from above along the direction of viewing the circuit board 17, the first busbar 26 and the second busbar 27 largely overlap each other.

[0048] like Figure 14 As shown by the middle arrow, when current flows from terminal P 12 through the second heat sink 22p, semiconductor switching element 24p, first busbar 26, second heat sink 22n, semiconductor switching element 24n, second busbar 27, and N terminal 13, the direction of the current flowing through the second busbar 27 is opposite to the direction of the current flowing through the first busbar 26. More specifically, as... Figure 14 and Figure 15 As indicated by the arrow in (a), the current flows in the first busbar 26U in the approximately negative y-axis direction. Figure 14 and Figure 15As indicated by the arrow in (b), the current flows in the second busbar 27 in the approximately positive y-axis direction. Since the second busbar 27 is configured to be separated from and approximately parallel to the first busbar 26 along the z-axis, and carries currents flowing in opposite directions, the magnetic field generated by the current flowing through the first busbar 26 and the magnetic field generated by the current flowing through the second busbar 27 cancel each other out. Therefore, even if the current flowing through the first busbar 26 and the current flowing through the second busbar 27 change drastically, changes in the magnetic field caused by current changes can be suppressed at the overlapping locations. As a result, malfunctions of the circuit board 17 due to changes in current or potential within the semiconductor module 10 can be suppressed.

[0049] Furthermore, in the semiconductor module 10, a second bus 27 is arranged between the circuit board 17 and the first bus 26 constituting the inverter circuit, as well as each semiconductor switching element 24p, 24n, etc., isolating the circuit board 17 from the inverter circuit. Therefore, the second bus 27 functions as an electromagnetic shield, suppressing the interaction between the magnetic field generated by the current change in the circuit board 17 and the magnetic field generated by the current change in the inverter circuit. As a result, malfunction of the circuit board 17 due to the magnetic field generated in the inverter circuit can be suppressed.

[0050] Furthermore, in the semiconductor module 10, the second bus 27 is grounded. Since the circuit board 17 and the inverter circuit are isolated by the grounded second bus 27, the second bus 27 functions as an electrostatic shield, suppressing the mutual interference of electrostatic noise generated by voltage changes in the circuit board 17 and the electrostatic noise generated by voltage changes in the inverter circuit. Specifically, when viewed from above along the direction of the circuit board 17, the second bus 27 covers the multiple semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn contained in each bridge branch, thus serving as an electrostatic shield and an electromagnetic shield, more effectively suppressing electrostatic noise and magnetic noise.

[0051] As described above, based on the structure embodied by the semiconductor module 10, the influence of magnetic noise or electrostatic noise generated by the inverter circuit on the circuit board 17 can be effectively suppressed. In inverter circuits that use power semiconductor elements such as RC-IGBTs as semiconductor switching elements, the magnetic noise and electrostatic noise of the circuit board, which is integrally sealed within the molding, increase due to the larger current and voltage variations. According to the semiconductor module 10, even if the inverter circuit using power semiconductor elements as semiconductor switching elements is sealed together with the circuit board 17 within the molding 11, the magnetic noise and electrostatic noise generated by the inverter circuit can be effectively suppressed, thereby suppressing malfunctions of the circuit board 17.

[0052] (Modified Example)

[0053] The circuit board 17 may also include a wireless communication circuit. By including a wireless communication circuit, such as... Figure 16 As shown, it is able to communicate with an external substrate 40 located outside the semiconductor module 10.

[0054] In addition, such as Figure 17 As shown, the semiconductor module 10 may also include signal terminals 41 and 42 exposed from the molding part 11. The signal terminals 41 and 42 are electrically connected to the circuit board 17. By connecting the signal terminals 41 and 42 to an external substrate 40 located outside the semiconductor module 10, signal reception and transmission between the circuit board 17 and the external substrate 40 can be achieved. Preferably, the signal terminals 41 and 42 protrude in the direction opposite to the side where the second busbar 27 is disposed. Additionally, as... Figure 17 As shown, signal terminals 41 and 42 can also be directly connected to the circuit board 17 by soldering or the like, but this is not a limitation. For example, within the molded part 11, signal terminals 41 and 42 and the circuit board 17 can also be separated, and signal terminals 41 and 42 can be indirectly connected to the circuit board 17 via bonding wires or the like.

[0055] like Figure 18 As shown, a low-shrinkage layer 50, 51 with a lower thermal shrinkage rate than the molded part 11 may also be included at a position within the molded part 11 that is separated from the circuit board 17 along the thickness direction of the circuit board 17. The low-shrinkage layer 50, 51 can suppress the warping and cracking of the insulating substrate 18 caused by the relatively high thermal shrinkage rate of the resin molded part 11 or the metal first heat dissipation substrate 21.

[0056] The low-shrinkage layers 50 and 51 can also be, for example, air layers. In this case, the low-shrinkage layers 50 and 51 can be formed by creating the air layer using a mold during molding. The low-shrinkage layer 50 is disposed above the driver IC 60, which is bonded to the upper surface of the circuit board 17, and the low-shrinkage layer 51 is disposed below the resistor, which is bonded to the lower surface of the circuit board 17, and above the second busbar 27. The low-shrinkage layers can be disposed only above or below the circuit board 17, or they can be disposed both above and below.

[0057] Furthermore, while the above embodiment illustrates an example where the multiple semiconductor switching elements constituting the inverter circuit are n-channel RC-IGBTs, it is not a limitation. The multiple semiconductor switching elements can be, for example, power semiconductor elements such as power MOSFETs or IGBTs, and the power MOSFETs or IGBTs can also be connected in reverse parallel with diodes to form each arm. Additionally, the multiple semiconductor switching elements can be n-channel or p-channel. Furthermore, the number of semiconductor switching elements constituting the inverter circuit is not limited to six.

[0058] Furthermore, in the above embodiment, the case where the second bus 27 is an N bus connected to the low-potential side of each bridge branch has been described, but it can also be a P bus connected to the high-potential side of each bridge branch. By replacing the P terminal 12 and the N terminal 13 and correspondingly reversing the connection direction of each semiconductor switching element, the structure in which the second bus 27 functions as a P bus can be realized.

[0059] According to the above embodiments, the following effects can be obtained.

[0060] Semiconductor module 10 includes a circuit board 17, a plurality of semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, 24Wn, a first bus 26U, 26V, 26W, a second bus 27, and a molding 11 that integrally seals these components. The plurality of semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, 24Wn are adapted for an inverter circuit connected to the circuit board 17 and are arranged along the plane of the circuit board 17. The first bus 26U, 26V, 26W connects the plurality of semiconductor switching elements (e.g., semiconductor switching elements 24Up, 24Un) included in the bridge branches of the inverter circuit in series with each other.

[0061] The second busbar 27 is connected to the low-potential side of the bridge branch and is disposed between the first buses 26U, 26V, 26W and the circuit board 17. When viewed from above along the direction of the circuit board 17, the first buses 26U, 26V, 26W and the second busbar 27 overlap at least partially, and the direction of the current flowing in the first buses 26U, 26V, 26W is opposite to the direction of the current flowing in the second busbar 27. Therefore, even if the current flowing through the first buses 26U, 26V, 26W and the current flowing through the second busbar 27 change drastically, the magnetic field change caused by the current change can be suppressed at the overlapping part. Therefore, in the case of drastic changes in the current or potential of each busbar due to the switching of the inverter circuit, the generation of magnetic noise can be suppressed. In addition, the second busbar 27 acts as an electromagnetic shield, which can suppress the influence of the magnetic field generated by the current change in the inverter circuit on the circuit board 17. As a result, the malfunction of the circuit board 17 due to changes in the current or potential within the semiconductor module 10 can be suppressed.

[0062] The second busbar 27 is the N busbar connected to the low-potential side of each bridge branch and is grounded. Therefore, the second busbar 27 functions as an electromagnetic shield, suppressing electrostatic noise caused by voltage changes in the circuit board 17, which could lead to malfunctions of the circuit board 17.

[0063] The circuit board 17 may also include a wireless communication circuit for communicating with the outside of the semiconductor module 10. In addition, the semiconductor module 10 may also include signal terminals 41, 42 that are exposed from the molding part 11 and electrically connected to the circuit board 17.

[0064] When viewed from above along the direction of the circuit board 17, the second busbar 27 covers the multiple semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn contained in each bridge branch. Therefore, the second busbar 27, which functions as an electrostatic shield and an electromagnetic shield, can more effectively suppress electrostatic noise and magnetic noise, and can more effectively suppress malfunctions of the circuit board 17.

[0065] The circuit board 17 may also include vias 17Up, 17Un, 17Vp, 17Vn, 17Wp, and 17Wn through which the bonding wires of the plurality of semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn pass. Similarly, the second busbar 27 may also include vias 27Up, 27Un, 27Vp, 27Vn, 27Wp, and 27Wn through which the bonding wires of the plurality of semiconductor switching elements 24Up, 24Un, 24Vp, 24Vn, 24Wp, and 24Wn pass.

[0066] The semiconductor module 10 may also include a low-shrinkage layer 50, 51 with a lower thermal shrinkage rate than the molded part 11 at a location within the molded part 11 that is separated from the circuit board 17 along the thickness direction of the circuit board 17. The low-shrinkage layer 50, 51 can mitigate thermal shrinkage and suppress damage to the semiconductor module 10.

[0067] While this disclosure has been described based on embodiments, it should be understood that this disclosure is not limited to the above embodiments and structures. This disclosure also includes various modifications and equivalent variations. Furthermore, various combinations and arrangements, and consequently, combinations and arrangements containing only one element, or more than or less thereof, also fall within the scope and spirit of this disclosure.

Claims

1. A semiconductor module, the semiconductor module comprising: Circuit board; Multiple semiconductor switching elements suitable for inverter circuits connected to the circuit board; Multiple busbars; And a molded part that integrally seals the circuit board, the plurality of semiconductor switching elements, and the plurality of busbars. The plurality of semiconductor switching elements are arranged along the plane of the circuit substrate. The plurality of busbars includes: The first busbar connects multiple semiconductor switching elements contained in each bridge branch of the inverter circuit in series with each other. as well as The second busbar is connected to either the high-potential side or the low-potential side of the bridge branch and is disposed between the first busbar and the circuit board. When viewed from above along the direction of the circuit board, at least a portion of the first busbar and the second busbar overlap each other. The direction of the current flowing in the first busbar is opposite to the direction of the current flowing in the second busbar. The circuit board includes through-holes through which the bonding wires of the plurality of semiconductor switching elements pass.

2. The semiconductor module as described in claim 1, characterized in that, When viewed from above along the direction of the circuit board, the second busbar covers a plurality of semiconductor switches contained in the bridge branch.

3. A semiconductor module, the semiconductor module comprising: Circuit board; Multiple semiconductor switching elements suitable for inverter circuits connected to the circuit board; Multiple busbars; And a molded part that integrally seals the circuit board, the plurality of semiconductor switching elements, and the plurality of busbars. The plurality of semiconductor switching elements are arranged along the plane of the circuit substrate. The plurality of busbars includes: The first busbar connects multiple semiconductor switching elements contained in each bridge branch of the inverter circuit in series with each other. as well as The second busbar is connected to either the high-potential side or the low-potential side of the bridge branch and is disposed between the first busbar and the circuit board. When viewed from above along the direction of the circuit board, at least a portion of the first busbar and the second busbar overlap each other. The direction of the current flowing in the first busbar is opposite to the direction of the current flowing in the second busbar. When viewed from above along the direction of the circuit board, the second busbar covers a plurality of semiconductor switches contained in the bridge branch.

4. The semiconductor module as described in any one of claims 1 to 3, characterized in that, The second busbar is a low-potential busbar connected to the low-potential side of the bridge branch and is grounded.

5. The semiconductor module as described in any one of claims 1 to 4, characterized in that, The circuit board includes a wireless communication circuit for communicating with the outside of the semiconductor module.

6. The semiconductor module as described in any one of claims 1 to 5, characterized in that, This includes signal terminals that are exposed from the molded part and electrically connected to the circuit board.

7. The semiconductor module as described in any one of claims 1 to 6, characterized in that, At a location within the molded part that is separated from the circuit board along the thickness direction of the circuit board, there is a low-shrinkage layer with a lower thermal shrinkage rate than the molded part.

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