Semiconductor Devices

Abstract

A semiconductor device capable of further improving edge breakdown voltage is provided. [Solution] The semiconductor device A1 includes a plurality of conductive members 20, a first semiconductor element, a second semiconductor element, and a sealing resin 50 that covers a portion of each of the plurality of conductive members 20, the first semiconductor element, and the second semiconductor element. The sealing resin 50 contains an electrically insulating filler 50B. The sealing resin 50 is assumed to have a square cross section S with a side length equal to 2 / 3 of the minimum spacing Pmin between two adjacent conductive members 20 among the plurality of conductive members 20. In this case, the square cross section S contains at least a portion of a plurality of fillers 50B, each with a particle size D equal to or greater than 1 / 8 of the minimum spacing Pmin.

Description

[Technical Field]

[0001] The present disclosure relates to a semiconductor device having a plurality of semiconductor elements mounted thereon to which voltages that are relatively different from one another are applied. [Background technology]

[0002] Semiconductor devices are used in inverter devices for electric vehicles (including hybrid vehicles) and home appliances. The inverter device includes, for example, a semiconductor device and switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). The semiconductor device includes a controller and a gate driver. In the inverter device, a control signal output from an external device is input to the controller of the semiconductor device. The controller converts the control signal into a PWM (Pulse Width Modulation) control signal and transmits it to the gate driver. The gate driver drives, for example, six switching elements at desired timing based on the PWM control signal. This generates three-phase AC power for driving a motor from DC power. For example, Patent Document 1 discloses an example of a semiconductor device (drive circuit) used in a motor drive device.

[0003] However, the power supply voltage supplied to the controller may differ from the power supply voltage supplied to the gate driver. In such cases, in a semiconductor device having multiple semiconductor elements mounted in a single package, a difference in power supply voltage occurs between the two conductive paths, the conductive path to the controller and the conductive path to the gate driver. Therefore, the dielectric strength of the semiconductor device is improved by providing a significant gap between the conductive path to the controller and the conductive path to the gate driver and filling the gap between the two conductive paths with a sealing resin. However, if the difference in power supply voltage applied to each of the two conductive paths is significant, further improvement in the dielectric strength is required. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-30049 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above circumstances, one object of the present disclosure is to provide a semiconductor device that can further improve the dielectric strength voltage. [Means for solving the problem]

[0006] The semiconductor device provided by the present disclosure comprises a plurality of conductive members including a first member and a second member, a first semiconductor element that is conductive to one of the plurality of conductive members, a second semiconductor element that is conductive to one of the plurality of conductive members and to which a voltage relatively different from the voltage applied to the first semiconductor element is applied, and a sealing resin that covers a portion of each of the plurality of conductive members, the first semiconductor element, and the second semiconductor element, wherein the voltage applied to the second member is relatively different from the voltage applied to the first member, and the sealing resin contains an electrically insulating filler, and when the sealing resin is assumed to have a square cross section with a side length equal to 2 / 3 of the minimum spacing between two adjacent conductive members among the plurality of conductive members, the square cross section contains at least eight or more of the fillers, each with a particle size that is 1 / 8 or more of the minimum spacing. [Effects of the Invention]

[0007] According to the above-described configuration of the present disclosure, it is possible to further improve the dielectric strength of the semiconductor device.

[0008] Other features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view of a semiconductor device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view corresponding to FIG. 1, seen through the sealing resin. [Figure 3] FIG. 3 is a front view of the semiconductor device shown in FIG. [Figure 4] FIG. 4 is a left side view of the semiconductor device shown in FIG. [Figure 5] FIG. 5 is a right side view of the semiconductor device shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a partially enlarged view of FIG. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. [Figure 10] FIG. 10 is a partially enlarged view of FIG. [Figure 11] FIG. 11 is a plan view of the semiconductor device according to the second embodiment of the present disclosure, seen through the sealing resin. [Figure 12] FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0011] A semiconductor device A1 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 10. The semiconductor device A1 includes a first semiconductor element 11, a second semiconductor element 12, an insulating element 13, a plurality of conductive members 20, a plurality of first wires 41, a plurality of second wires 42, a plurality of third wires 43, a plurality of fourth wires 44, a plurality of fifth wires 45, a plurality of sixth wires 46, and a sealing resin 50. The plurality of conductive members 20 include a first member 21, a second member 22, a plurality of first terminals 31, and a plurality of second terminals 32. The semiconductor device A1 is surface-mounted on a wiring board of an inverter device, for example, in an electric vehicle or a hybrid vehicle. The package format of the semiconductor device A1 is a small outline package (SOP). However, the package format of the semiconductor device A1 is not limited to SOP. Here, for ease of understanding, FIG. 2 shows the sealing resin 50 in perspective. In FIG. 2, the transparent sealing resin 50 is indicated by an imaginary line (double-dashed line).

[0012] In the description of semiconductor device A1, the thickness direction of each of first semiconductor element 11 and second semiconductor element 12 is referred to as the "thickness direction z." The direction perpendicular to thickness direction z is referred to as the "first direction x." The direction perpendicular to both thickness direction z and first direction x is referred to as the "second direction y."

[0013] The first semiconductor element 11, the second semiconductor element 12, and the insulating element 13 are elements that form the functional core of the semiconductor device A1. In the semiconductor device A1, the first semiconductor element 11, the second semiconductor element 12, and the insulating element 13 are configured as individual elements. In the first direction x, the second semiconductor element 12 is located on the opposite side of the insulating element 13 from the first semiconductor element 11. When viewed in the thickness direction z, the first semiconductor element 11, the second semiconductor element 12, and the insulating element 13 are rectangular in shape with their longer sides extending in the second direction y.

[0014] The first semiconductor element 11 is a controller (control element) of a gate driver that drives switching elements such as IGBTs, MOSFETs, etc. The first semiconductor element 11 has a circuit that converts a control signal input from an ECU or the like into a PWM control signal, a transmission circuit that transmits the PWM control signal to the second semiconductor element 12, and a reception circuit that receives an electrical signal from the second semiconductor element 12.

[0015] The second semiconductor element 12 is a gate driver (drive element) for driving the switching element. The second semiconductor element 12 has a receiving circuit for receiving a PWM control signal, a circuit for driving the switching element based on the PWM control signal, and a transmitting circuit for transmitting an electrical signal to the first semiconductor element 11. The electrical signal may be, for example, an output signal from a temperature sensor arranged near the motor.

[0016] The isolation element 13 is an element for transmitting PWM control signals and other electrical signals in an isolated state. In the semiconductor device A1, the isolation element 13 is an inductive type. An example of an inductive isolation element 13 is an isolation transformer. An isolation transformer transmits electrical signals in an isolated state by inductively coupling two inductors (coils). The isolation element 13 has a silicon substrate. An inductor made of copper (Cu) is formed on the substrate. The inductors include a transmitting inductor and a receiving inductor, and these inductors are stacked in the thickness direction z. A dielectric layer made of silicon dioxide (SiO2) or the like is interposed between the transmitting inductor and the receiving inductor. The dielectric layer electrically insulates the transmitting inductor from the receiving inductor. Alternatively, the isolation element 13 may be a capacitive type. An example of a capacitive isolation element 13 is a capacitor. The isolation element 13 may also be a photocoupler.

[0017] In the semiconductor device A1, the voltage applied to the first semiconductor element 11 and the voltage applied to the second semiconductor element 12 are relatively different. Therefore, a potential difference occurs between the first semiconductor element 11 and the second semiconductor element 12. Furthermore, in the semiconductor device A1, the power supply voltage supplied to the second semiconductor element 12 is higher than the power supply voltage supplied to the first semiconductor element 11.

[0018] Therefore, in the semiconductor device A1, a first circuit including a first semiconductor element 11 as a component and a second circuit including a second semiconductor element 12 as a component are insulated from each other by an insulating element 13. The components of the first circuit include, in addition to the first semiconductor element 11, a first member 21, a plurality of first terminals 31, a plurality of first wires 41, a plurality of third wires 43, and a plurality of fifth wires 45. The components of the second circuit include, in addition to the second semiconductor element 12, a second member 22, a plurality of second terminals 32, a plurality of second wires 42, a plurality of fourth wires 44, and a plurality of sixth wires 46. The first circuit and the second circuit have relatively different potentials. In the semiconductor device A1, the potential of the second circuit is higher than the potential of the first circuit. Furthermore, the insulating element 13 relays mutual signals between the first circuit and the second circuit. For example, in an inverter device for an electric vehicle or a hybrid vehicle, the voltage applied to the ground of the first semiconductor element 11 may be approximately 0V, while the voltage applied to the ground of the second semiconductor element 12 may transiently become 600V or more.

[0019] As shown in FIGS. 2 and 6, the first semiconductor element 11 has a plurality of first electrodes 111. The plurality of first electrodes 111 are provided on the upper surface of the first semiconductor element 11 (the surface facing the same direction as the first mounting surface 211A of the first island portion 211 of the first member 21, which will be described later). The composition of the plurality of first electrodes 111 includes, for example, aluminum (Al). In other words, each of the first electrodes 111 contains aluminum. The plurality of first electrodes 111 are electrically connected to a circuit formed in the first semiconductor element 11.

[0020] 2 and 6, the insulating element 13 is located between the first semiconductor element 11 and the second semiconductor element 12 in the first direction x. A plurality of first relay electrodes 131 and a plurality of second relay electrodes 132 are provided on the upper surface of the insulating element 13 (the surface facing the same direction as the above-mentioned first mounting surface 211A). Each of the plurality of first relay electrodes 131 and the plurality of second relay electrodes 132 is electrically connected to either the transmitting inductor or the receiving inductor. The plurality of first relay electrodes 131 are arranged in the second direction y and are located closer to the first semiconductor element 11 than the second semiconductor element 12 in the first direction x. The plurality of second relay electrodes 132 are arranged in the second direction y and are located closer to the second semiconductor element 12 than the first semiconductor element 11 in the first direction x.

[0021] 2 and 6, the second semiconductor element 12 has a plurality of second electrodes 121. The plurality of second electrodes 121 are provided on the upper surface of the second semiconductor element 12 (a surface facing in the same direction as a second mounting surface 221A of a second island portion 221 of the second member 22, which will be described later). The composition of the plurality of second electrodes 121 includes aluminum, for example. The plurality of second electrodes 121 are electrically connected to a circuit formed in the second semiconductor element 12.

[0022] The plurality of conductive members 20 form conductive paths between the first semiconductor element 11, the insulating element 13, and the second semiconductor element 12 and the wiring board on which the semiconductor device A1 is mounted. The plurality of conductive members 20 are obtained from the same lead frame. The lead frame contains copper in its composition. As described above, the plurality of conductive members 20 include a first member 21, a second member 22, a plurality of first terminals 31, and a plurality of second terminals 32.

[0023] 1 and 2, the first member 21 and the second member 22 are positioned apart from each other in the first direction x. In the semiconductor device A1, the first semiconductor element 11 and the insulating element 13 are mounted on the first member 21, and the second semiconductor element 12 is mounted on the second member 22. The voltage applied to the second member 22 is relatively different from the voltage applied to the first member 21. In the semiconductor device A1, the voltage applied to the second member 22 is higher than the voltage applied to the first member 21.

[0024] As shown in FIG. 2, the first member 21 has a first island portion 211 and two first suspension lead portions 212. As shown in FIGS. 6 and 7, the first island portion 211 has a first mounting surface 211A facing the thickness direction z. In the semiconductor device A1, the first semiconductor element 11 and the insulating element 13 are mounted on the first mounting surface 211A. The first semiconductor element 11 and the insulating element 13 are bonded to the first mounting surface 211A via a conductive bonding material (such as solder or metal paste) not shown. The first island portion 211 is covered with a sealing resin 50. The thickness of the first island portion 211 is, for example, not less than 100 μm and not more than 300 μm.

[0025] 2 and 6, a plurality of through holes 213 are formed in the first island portion 211. Each of the plurality of through holes 213 penetrates the first island portion 211 in the thickness direction z and extends along the second direction y. When viewed in the thickness direction z, at least one of the plurality of through holes 213 is located between the first semiconductor element 11 and the insulating element 13. The plurality of through holes 213 are arranged along the second direction y.

[0026] As shown in FIG. 2, the two first suspension leads 212 extend from both sides of the first island portion 211 in the second direction y. The two first suspension leads 212 are spaced apart from each other in the second direction y. At least one of the two first suspension leads 212 is electrically connected to the ground of the first semiconductor element 11 via a fifth wire 45. Each of the two first suspension leads 212 has a covered portion 212A and an exposed portion 212B. The covered portion 212A is connected to the first island portion 211 and is covered with the sealing resin 50. The exposed portion 212B is connected to the covered portion 212A and is exposed from the sealing resin 50. When viewed in the thickness direction z, the exposed portion 212B extends along the first direction x. When viewed in the second direction y, as shown in FIG. 3, the exposed portion 212B is bent in a gull-wing shape. The surface of the exposed portion 212B may be plated with, for example, tin (Sn).

[0027] As shown in FIG. 2, the second member 22 has a second island portion 221 and two second suspension lead portions 222. As shown in FIG. 6, the second island portion 221 has a second mounting surface 221A facing the thickness direction z. In the semiconductor device A1, the second semiconductor element 12 is mounted on the second mounting surface 221A. The second semiconductor element 12 is bonded to the second mounting surface 221A via a conductive bonding material (such as solder or metal paste) not shown. The second island portion 221 is covered with a sealing resin 50. The thickness of the second island portion 221 is, for example, not less than 100 μm and not more than 300 μm. When viewed in the first direction x, the second island portion 221 overlaps the first island portion 211 of the first member 21.

[0028] As shown in FIG. 2, the two second suspension leads 222 extend from both sides of the second island portion 221 in the second direction y. The two second suspension leads 222 are spaced apart from each other in the second direction y. At least one of the two second suspension leads 222 is electrically connected to the ground of the second semiconductor element 12 via a sixth wire 46. Each of the two second suspension leads 222 has a covering portion 222A and an exposed portion 222B. The covering portion 222A is connected to the second island portion 221 and is covered with the sealing resin 50. The exposed portion 222B is connected to the covering portion 222A and is exposed from the sealing resin 50. When viewed in the thickness direction z, the exposed portion 222B extends along the first direction x. When viewed in the second direction y, as shown in FIG. 3, the exposed portion 222B is bent in a gull-wing shape. The surface of the exposed portion 222B may be plated with tin, for example.

[0029] 2 and 6, the first island portion 211 of the first member 21 and the second island portion 221 of the second member 22 are spaced apart from each other in the first direction x by a distance P. As shown in FIG. 10, the distance P is the minimum distance between the first island portion 211 and the second island portion 221.

[0030] As shown in FIGS. 1 and 2 , the multiple first terminals 31 are located on one side in the first direction x. More specifically, the multiple first terminals 31 are located on the opposite side of the first island portion 211 of the first member 21 from the second island portion 221 of the second member 22 in the first direction x. The multiple first terminals 31 are arranged along the second direction y. At least one of the multiple first terminals 31 is electrically connected to the first semiconductor element 11 via a third wire 43. The multiple first terminals 31 include multiple first intermediate terminals 31A and two first side terminals 31B. The two first side terminals 31B are located on both sides of the multiple first intermediate terminals 31A in the second direction y. Each of the two first side terminals 31B is located between one of the two first suspension lead portions 212 of the first member 21 and the first intermediate terminal 31A located closest to that first suspension lead portion 212 in the second direction y.

[0031] As shown in FIGS. 2 and 6, the multiple first terminals 31 have a covered portion 311 and an exposed portion 312. The covered portion 311 is covered with a sealing resin 50. The dimension in the first direction x of the covered portion 311 of each of the two first side terminals 31B is larger than the dimension in the first direction x of the covered portion 311 of each of the multiple first intermediate terminals 31A. As shown in FIG. 9, the covered portion 311 has a metal layer 33. The metal layer 33 is located on one side of the covered portion 311 in the thickness direction z (the side toward which the first mounting surface 211A of the first island portion 211 of the first member 21 faces). The metal layer 33 is in contact with the sealing resin 50. The metal layer 33 contains silver.

[0032] 2 and 6, the exposed portion 312 is connected to the covering portion 311 and is exposed from the sealing resin 50. When viewed in the thickness direction z, the exposed portion 312 extends along the first direction x. When viewed in the second direction y, the exposed portion 312 is bent in a gull-wing shape. The shape of the exposed portion 312 is the same as the shape of each of the exposed portions 212B of the two first suspension lead portions 212 of the first member 21. The surface of the exposed portion 312 may be tin-plated, for example.

[0033] As shown in FIGS. 1 and 2 , the multiple second terminals 32 are located on the other side in the first direction x. More specifically, the multiple second terminals 32 are located on the opposite side of the multiple first terminals 31 with respect to the first island portion 211 of the first member 21 in the first direction x. The multiple second terminals 32 are arranged along the second direction y. At least one of the multiple second terminals 32 is electrically connected to the second semiconductor element 12 via a fourth wire 44. The multiple second terminals 32 include multiple second intermediate terminals 32A and two second side terminals 32B. The two second side terminals 32B are located on both sides of the multiple second intermediate terminals 32A in the second direction y. In the second direction y, one of the two second suspension lead portions 222 of the second member 22 is located between one of the two second side terminals 32B and the second intermediate terminal 32A located closest to that second side terminal 32B.

[0034] 2 and 6, the multiple second terminals 32 have a covered portion 321 and an exposed portion 322. The covered portion 321 is covered with a sealing resin 50. The dimension in the first direction x of the covered portion 321 of each of the two second side terminals 32B is larger than the dimension in the first direction x of the covered portion 321 of each of the multiple second intermediate terminals 32A. Like the covered portions 311 of the multiple first terminals 31, the covered portion 321 has a metal layer 33 shown in FIG. 9. The metal layer 33 is located on one side of the covered portion 321 in the thickness direction z (the side toward which the second mounting surface 221A of the second island portion 221 of the second member 22 faces). The metal layer 33 is in contact with the sealing resin 50.

[0035] 2 and 6, the exposed portion 322 is connected to the covering portion 321 and is exposed from the sealing resin 50. When viewed in the thickness direction z, the exposed portion 322 extends along the first direction x. When viewed in the second direction y, as shown in FIG. 3, the exposed portion 322 is bent in a gull-wing shape. The shape of the exposed portion 322 is the same as the shape of each of the exposed portions 222B of the two second suspension lead portions 222 of the second member 22. The surface of the exposed portion 322 may be plated with tin, for example.

[0036] The plurality of first wires 41, the plurality of second wires 42, the plurality of third wires 43, the plurality of fourth wires 44, the plurality of fifth wires 45, and the plurality of sixth wires 46, together with the plurality of conductive members 20, form a conductive path for the first semiconductor element 11, the second semiconductor element 12, and the insulating element 13 to perform their predetermined functions.

[0037] 2 and 6, each of the multiple first wires 41 is bonded to one of the multiple first relay electrodes 131 of the insulating element 13 and one of the multiple first electrodes 111 of the first semiconductor element 11. This allows the first semiconductor element 11 and the insulating element 13 to be electrically connected to each other. The multiple first wires 41 are arranged along the second direction y. The composition of the multiple first wires 41 includes gold (Au).

[0038] As shown in FIGS. 2 and 6 , each of the multiple second wires 42 is bonded to one of the multiple second relay electrodes 132 of the insulating element 13 and one of the multiple second electrodes 121 of the second semiconductor element 12. This allows the second semiconductor element 12 and the insulating element 13 to be electrically connected to each other. The multiple second wires 42 are arranged along the second direction y. In the semiconductor device A1, the multiple second wires 42 straddle the first island portion 211 of the first member 21 and the second island portion 221 of the second member 22. The composition of the multiple second wires 42 includes gold.

[0039] 2 and 6, each of the multiple third wires 43 is joined to one of the multiple first electrodes 111 of the first semiconductor element 11 and to the coating portion 311 of one of the multiple first terminals 31. As a result, at least one of the multiple first terminals 31 is electrically connected to the first semiconductor element 11. The composition of the multiple third wires 43 includes gold. Alternatively, the composition of the multiple third wires 43 may include copper.

[0040] 2 and 6, each of the multiple fourth wires 44 is joined to one of the multiple second electrodes 121 of the second semiconductor element 12 and to the coating portion 321 of one of the multiple second terminals 32. As a result, at least one of the multiple second terminals 32 is electrically connected to the second semiconductor element 12. The composition of the multiple fourth wires 44 includes gold. Alternatively, the composition of the multiple fourth wires 44 may include copper.

[0041] 2, each of the plurality of fifth wires 45 is joined to one of the plurality of first electrodes 111 of the first semiconductor element 11 and to the covering portion 212A of one of the two first suspension lead portions 212 of the first member 21. This allows the first semiconductor element 11 to be electrically connected to the first member 21. The composition of the plurality of fifth wires 45 includes gold. Alternatively, the composition of the plurality of fifth wires 45 may include copper.

[0042] 2, each of the plurality of sixth wires 46 is joined to one of the plurality of second electrodes 121 of the second semiconductor element 12 and to the covering portion 222A of one of the two second suspension lead portions 222 of the second member 22. This allows the second semiconductor element 12 to be electrically connected to the second member 22. The composition of the plurality of sixth wires 46 includes gold. Alternatively, the composition of the plurality of sixth wires 46 may include copper.

[0043] As shown in FIG. 1 , the sealing resin 50 covers the first semiconductor element 11, the second semiconductor element 12, the insulating element 13, and a portion of each of the plurality of conductive members 20. The sealing resin 50 further covers the plurality of first wires 41, the plurality of second wires 42, the plurality of third wires 43, the plurality of fourth wires 44, the plurality of fifth wires 45, and the plurality of sixth wires 46. The sealing resin 50 has electrical insulation properties. The sealing resin 50 insulates the first member 21 and the second member 22 from each other. As shown in FIG. 9 , the sealing resin 50 contains a filler 50B. The filler 50B has electrical insulation properties. When viewed in the thickness direction z, the sealing resin 50 has a rectangular shape.

[0044] As shown in FIGS. 3 to 5, the sealing resin 50 has a top surface 51, a bottom surface 52, a pair of first side surfaces 53, and a pair of second side surfaces .

[0045] 3 to 5, the top surface 51 and the bottom surface 52 are spaced apart from each other in the thickness direction z. The top surface 51 and the bottom surface 52 face in opposite directions in the thickness direction z. Each of the top surface 51 and the bottom surface 52 is flat (or approximately flat).

[0046] 3 to 5, the pair of first side surfaces 53 are connected to the top surface 51 and the bottom surface 52 and are spaced apart from each other in the first direction x. Of the pair of first side surfaces 53, the first side surface 53 located on one side in the first direction x exposes the exposed portions 212B of the two first suspension lead portions 212 of the first member 21 and the exposed portions 312 of the multiple first terminals 31. Of the pair of first side surfaces 53, the first side surface 53 located on the other side in the first direction x exposes the exposed portions 222B of the two second suspension lead portions 222 of the second member 22 and the exposed portions 322 of the multiple second terminals 32.

[0047] As shown in FIGS. 3 to 5 , each of the pair of first side surfaces 53 includes a first upper portion 531, a first lower portion 532, and a first intermediate portion 533. One side of the first upper portion 531 in the thickness direction z is connected to the top surface 51, and the other side in the thickness direction z is connected to the first intermediate portion 533. The first upper portion 531 is inclined with respect to the top surface 51. One side of the first lower portion 532 in the thickness direction z is connected to the bottom surface 52, and the other side in the thickness direction z is connected to the first intermediate portion 533. The first lower portion 532 is inclined with respect to the bottom surface 52. One side of the first intermediate portion 533 in the thickness direction z is connected to the first upper portion 531, and the other side in the thickness direction z is connected to the first lower portion 532. The in-plane directions of the first intermediate portion 533 are the thickness direction z and the second direction y. When viewed in the thickness direction z, the first intermediate portion 533 is located outward from the top surface 51 and the bottom surface 52. From the first intermediate portion 533 of the pair of first side surfaces 53, exposed portions 212B of the two first suspension lead portions 212 of the first member 21, exposed portions 222B of the two second suspension lead portions 222 of the second member 22, exposed portions 312 of the multiple first terminals 31, and exposed portions 322 of the multiple second terminals 32 are exposed.

[0048] 3 to 5, the pair of second side surfaces 54 are connected to the top surface 51 and the bottom surface 52 and are spaced apart from each other in the second direction y. As shown in FIG. 1, the first member 21, the second member 22, the plurality of first terminals 31, and the plurality of second terminals 32 are spaced apart from the pair of second side surfaces 54.

[0049] As shown in FIGS. 3 to 5 , each of the pair of second side surfaces 54 includes a second upper portion 541, a second lower portion 542, and a second intermediate portion 543. The second upper portion 541 is connected to the top surface 51 on one side in the thickness direction z and connected to the second intermediate portion 543 on the other side in the thickness direction z. The second upper portion 541 is inclined with respect to the top surface 51. The second lower portion 542 is connected to the bottom surface 52 on one side in the thickness direction z and connected to the second intermediate portion 543 on the other side in the thickness direction z. The second lower portion 542 is inclined with respect to the bottom surface 52. The second intermediate portion 543 is connected to the second upper portion 541 on one side in the thickness direction z and connected to the second lower portion 542 on the other side in the thickness direction z. The in-plane directions of the second intermediate portion 543 are the thickness direction z and the second direction y. The second intermediate portion 543 is located outward from the top surface 51 and the bottom surface 52 when viewed in the thickness direction z.

[0050] 9 and 10, the encapsulating resin 50 includes a base material 50A and a filler 50B. The base material 50A mainly contains an epoxy resin and a hardener. The filler 50B contains silicon dioxide. In the semiconductor device A1, the weight percentage of the filler 50B is approximately 90% of the encapsulating resin 50.

[0051] The assumed square cross section S of the sealing resin 50 shown in FIG. 9 includes at least eight or more fillers 50B, each having a particle size D equal to or greater than a reference value. The particle size D is the maximum diameter of each filler 50B in the square cross section S. In FIGS. 9 and 10, fillers 50B having a particle size D equal to or greater than the reference value are indicated by diagonal lines. The square cross section S crosses only the sealing resin 50. The position of the square cross section S in the sealing resin 50 is not limited. The length of one side of the square cross section S and the reference value of the particle size D of the filler 50B are determined by the minimum spacing Pmin shown in FIG. 8. The minimum spacing Pmin is the minimum value of the spacing between two adjacent conductive members 20 among the multiple conductive members 20. In the semiconductor device A1, the minimum spacing Pmin is the smaller of the minimum value of the spacing between two adjacent first terminals 31 in the second direction y and the minimum value of the spacing between two adjacent second terminals 32 in the second direction y. In the semiconductor device A1, the minimum spacing Pmin is 150 μm.

[0052] The length of one side of the assumed square cross section S of the sealing resin 50 is equal to 2 / 3 of the minimum spacing Pmin. In the semiconductor device A1, the length of one side of the square cross section S is 100 μm. The reference value of the particle size D of the filler 50B is equal to 1 / 8 of the minimum spacing Pmin. In the semiconductor device A1, the reference value of the particle size D is 18.75 μm. Therefore, in the semiconductor device A1, the square cross section S having a side length of 100 μm contains at least eight or more filler particles 50B, each having a particle size D of 18.75 μm or more. Furthermore, the maximum value of the particle size D of the filler 50B is 1 / 2 of the minimum spacing Pmin. Therefore, in the semiconductor device A1, the maximum value of the particle size D of the filler 50B is 75 μm.

[0053] Since the position of the square cross section S in the sealing resin 50 is not limited, as shown in Fig. 9, the particle size distribution of the filler 50B contained in the square cross section S is uniform in the sealing resin 50. Furthermore, the distance P between the first member 21 (first island portion 211) and the second member 22 (second island portion 221) shown in Fig. 10 is 1.0 to 3.0 times the minimum distance Pmin.

[0054] A motor driver circuit in an inverter device typically includes a half-bridge circuit including a low-side (low potential side) switching element and a high-side (high potential side) switching element. The following description focuses on the case where these switching elements are MOSFETs. Here, for the low-side switching element, the reference potentials of the source of the switching element and the gate driver driving the switching element are both ground. For the high-side switching element, the reference potentials of the source of the switching element and the gate driver driving the switching element are both equivalent to the potential at the output node of the half-bridge circuit. The potential at the output node changes depending on the driving of the high-side and low-side switching elements, so the reference potential of the gate driver driving the high-side switching element also changes. When the high-side switching element is on, the reference potential is equivalent to the voltage applied to the drain of the high-side switching element (e.g., 600 V or higher). In the semiconductor device A1, the ground of the first semiconductor element 11 and the ground of the second semiconductor element 12 are separated. Therefore, when the semiconductor device A1 is used as a gate driver for driving a high-side switching element, a voltage equivalent to the voltage applied to the drain of the high-side switching element is transiently applied to the ground of the second semiconductor element 12.

[0055] Next, the effects of the semiconductor device A1 will be described.

[0056] The semiconductor device A1 includes a plurality of conductive members 20 including a first member 21 and a second member 22, and a sealing resin 50 that covers a portion of each of the plurality of conductive members 20. The voltage applied to the second member 22 is relatively different from the voltage applied to the first member 21. The sealing resin 50 contains an electrically insulating filler 50B. The square cross section S of the sealing resin 50, whose side length is 2 / 3 of the minimum spacing Pmin between two adjacent conductive members 20 among the plurality of conductive members 20, contains at least a portion of eight or more fillers 50B, each having a particle size D that is 1 / 8 or more of the minimum spacing Pmin.

[0057] Here, it has been confirmed that when the semiconductor device A1 experiences dielectric breakdown, the breakdown occurs at the interface 50C between the base material 50A and the filler 50B of the sealing resin 50, as shown in FIG. 9. Furthermore, when the semiconductor device A1 experiences dielectric breakdown, the probability of breakdown is extremely high in the sealing resin 50 that fills the gap P between the first member 21 and the second member 22, to which relatively different voltages are applied. Dielectric breakdown occurs when charged carriers move from one conductive member 20 to the other conductive member 20 through the sealing resin 50 embedded between two adjacent conductive members 20. The carriers move along the interface 50C between the base material 50A and the filler 50B in the sealing resin 50. Therefore, by adopting the above-described configuration of the semiconductor device A1, the travel distance L of the carriers from the second mounting surface 221A of the second island portion 221 (second member 22) to the first mounting surface 211A of the first island portion 211 (first member 21) is longer, as shown in FIG. 10. This increases the time it takes for the semiconductor device A1 to experience dielectric breakdown. Therefore, according to the semiconductor device A1, it is possible to further improve the dielectric strength.

[0058] The length of one side of the square cross section S of the sealing resin 50 and the reference value of the particle size D of the filler 50B in the sealing resin 50 are determined by the minimum distance Pmin between two adjacent conductive members 20 among the plurality of conductive members 20. As a result, fillers 50B having particle size D equal to or greater than the reference value are excluded from the fillers 50B that do not contribute to improving the dielectric strength voltage of the semiconductor device A1. Furthermore, the maximum value of the particle size D of the filler 50B is half the minimum distance Pmin. As a result, during the manufacture of the semiconductor device A1, the fluidized sealing resin 50 passes smoothly between two adjacent conductive members 20, preventing improper filling of the sealing resin 50.

[0059] In the semiconductor device A1, the distance P between the first member 21 and the second member 22 is important for further improving the dielectric strength of the semiconductor device A1. The distance P is preferably 1.0 to 3.0 times the minimum distance Pmin between two adjacent conductive members 20 among the plurality of conductive members 20. If the distance P exceeds 3.0 times the minimum distance Pmin, although this contributes to further improving the dielectric strength of the semiconductor device A1, it will undesirably result in an increase in the size of the semiconductor device A1.

[0060] In the semiconductor device A1, a portion of each of the multiple conductive members 20 is exposed from one of the pair of first side surfaces 53 of the sealing resin 50. This configuration is achieved by having the two first suspension lead portions 212 of the first member 21 exposed from one side of the sealing resin 50 in the first direction x, and the two second suspension lead portions 222 of the second member 22 exposed from the other side of the sealing resin 50 in the first direction x. In this case, the multiple conductive members 20 are located away from the pair of second side surfaces 54 of the sealing resin 50. As a result, in the semiconductor device A1, metal members such as island supports are not exposed from the pair of second side surfaces 54. This can improve the dielectric strength of the semiconductor device A1.

[0061] In the semiconductor device A1, a plurality of through holes 213 are formed in the first island portion 211 of the first member 21, which has an area larger than that of the second island portion 221 of the second member 22. As a result, during the manufacture of the semiconductor device A1, the fluidized sealing resin 50 passes through the plurality of through holes 213, preventing imperfect filling of the sealing resin 50. Therefore, the occurrence of voids in the sealing resin 50 can be effectively suppressed. This contributes to suppressing a decrease in the dielectric strength voltage of the semiconductor device A1.

[0062] The semiconductor device A1 further includes a first wire 41 and a second wire 42. The first wire 41 is bonded to the insulating element 13 and the first semiconductor element 11. The second wire 42 is bonded to the insulating element 13 and the second semiconductor element 12. The first wire 41 and the second wire 42 contain gold. In this case, when forming the first wire 41, the initial bonded portion of the first wire 41 is formed on the first relay electrode 131 of the insulating element 13, and the final bonded portion of the first wire 41 is formed on the multiple first terminals 31 and one of the two first suspended lead portions 212 of the first member 21. This allows the first wire 41 to have a shape that ensures as long a distance as possible in the thickness direction z between the top of the first wire 41 located closest to the top surface 51 of the sealing resin 50 and the insulating element 13. Similarly, when forming the second wire 42, the first joint of the second wire 42 is formed on the second relay electrode 132 of the insulating element 13, and the last joint is formed on the plurality of second terminals 32 and one of the two second suspension lead portions 222 of the second member 22. This allows the second wire 42 to be shaped such that the distance in the thickness direction z between the top of the second wire 42 located closest to the top surface 51 and the insulating element 13 is as long as possible. This contributes to further improving the dielectric strength of the semiconductor device A1.

[0063] A semiconductor device A2 according to a second embodiment of the present disclosure will be described with reference to Figures 11 and 12. In these figures, elements that are the same as or similar to those in the semiconductor device A1 described above are given the same reference numerals, and duplicated explanations will be omitted. For ease of understanding, Figure 11 shows the sealing resin 50 through which light is transmitted. In Figure 11, the transmitted sealing resin 50 is shown by imaginary lines.

[0064] In the semiconductor device A2, the mounting form of the insulating element 13 differs from that of the semiconductor device A1 described above.

[0065] 11 and 12, the insulating element 13 is mounted on the second mounting surface 221A of the second island portion 221 of the second member 22. Therefore, in the semiconductor device A2, a plurality of first wires 41 straddle between the first island portion 211 of the first member 21 and the second island portion 221 of the second member 22. In this way, even if the potential of the second island portion 221 is higher than the potential of the first island portion 211, the insulating element 13 can be mounted on the second island portion 221.

[0066] Next, the effects of the semiconductor device A2 will be described.

[0067] The semiconductor device A2 includes a plurality of conductive members 20, including a first member 21 and a second member 22, and a sealing resin 50 that partially covers each of the plurality of conductive members 20. The voltage applied to the second member 22 is relatively different from the voltage applied to the first member 21. The sealing resin 50 contains electrically insulating fillers 50B. The square cross section S of the sealing resin 50, whose side length is two-thirds the minimum spacing Pmin between two adjacent conductive members 20, contains at least a portion of eight or more fillers 50B, each with a particle size D equal to or greater than one-eighth of the minimum spacing Pmin. Therefore, the semiconductor device A2 can also further improve the dielectric strength. Furthermore, by sharing a configuration with the semiconductor device A1, the semiconductor device A2 achieves the same effects as the semiconductor device A1.

[0068] The present disclosure is not limited to the above-described embodiment, and the specific configuration of each part of the present disclosure can be freely modified in various ways.

[0069] The present disclosure includes the embodiments described in the following appendices. Appendix 1. a plurality of conductive members including a first member and a second member; a first semiconductor element that is electrically connected to any one of the plurality of conductive members; a second semiconductor element that is electrically connected to any one of the plurality of conductive members and to which a voltage relatively different from the voltage applied to the first semiconductor element is applied; a sealing resin that covers a portion of each of the plurality of conductive members, the first semiconductor element, and the second semiconductor element; a voltage applied to the second member is relatively different from a voltage applied to the first member; the sealing resin contains an electrically insulating filler, When the sealing resin is assumed to have a square cross section with a side length equal to 2 / 3 of the minimum distance between two adjacent conductive members among the plurality of conductive members, The semiconductor device, wherein the square cross section contains at least eight or more of the fillers, each having a particle size equal to or greater than 1 / 8 of the minimum spacing. Appendix 2. 2. The semiconductor device according to claim 1, wherein the maximum particle size of the filler is half the minimum spacing. Appendix 3. the first member and the second member are positioned apart from each other in a first direction perpendicular to a thickness direction of each of the first semiconductor element and the second semiconductor element, the first semiconductor element is mounted on the first member, the second semiconductor element is mounted on the second member, 3. The semiconductor device according to claim 2, wherein the distance between the first member and the second member is 1.0 to 3.0 times the minimum distance. Appendix 4. 4. The semiconductor device according to claim 3, wherein the first semiconductor element is electrically connected to the first member. Appendix 5. 5. The semiconductor device according to claim 4, wherein the second semiconductor element is electrically connected to the second member. Appendix 6. the plurality of conductive members include a plurality of first terminals located on one side in the first direction and a plurality of second terminals located on the other side in the first direction, the first semiconductor element is electrically connected to the plurality of first terminals; 6. The semiconductor device according to claim 3, wherein the second semiconductor element is electrically connected to the second terminals. Appendix 7. 7. The semiconductor device according to claim 6, wherein the plurality of first terminals and the plurality of second terminals are arranged along a second direction perpendicular to the first direction. Appendix 8. the first member has a first island portion on which the first semiconductor element is mounted, and two first suspension lead portions connected to both sides of the first island portion in the second direction, 8. The semiconductor device according to claim 7, wherein the two first suspension lead portions are exposed from one side of the sealing resin in the first direction. Appendix 9. the second member has a second island portion on which the second semiconductor element is mounted, and two second suspension lead portions connected to both sides of the second island portion in the second direction, 9. The semiconductor device according to claim 8, wherein the two second suspension lead portions are exposed from the other side of the sealing resin in the first direction. Appendix 10. 10. The semiconductor device according to claim 9, wherein the second island portion overlaps the first island portion when viewed in the first direction. Appendix 11. 11. The semiconductor device according to any one of claims 3 to 10, wherein the voltage applied to the second member is higher than the voltage applied to the first member. Appendix 12. an insulating element that relays mutual signals between the first semiconductor element and the second semiconductor element and insulates the first semiconductor element and the second semiconductor element from each other; 12. The semiconductor device according to any one of claims 3 to 11, wherein the insulating element is an inductive type. Appendix 13. 13. The semiconductor device according to claim 12, wherein the insulating element is mounted on the first member. Appendix 14. 13. The semiconductor device according to claim 12, wherein the insulating element is mounted on the second member. Appendix 15. Further comprising a first wire and a second wire; the first wire is bonded to the insulating element and the first semiconductor element; the second wire is bonded to the insulating element and the second semiconductor element; 15. The semiconductor device according to any one of claims 12 to 14, wherein the first wire and the second wire have a composition including gold. Appendix 16. 16. The semiconductor device according to any one of claims 1 to 15, wherein the filler has a composition including silicon dioxide. [Explanation of symbols]

[0070] A1, A2: Semiconductor device 11: First semiconductor element 111: First electrode 12: Second semiconductor element 121: Second electrode 13: Insulating element 131: First relay electrode 132: Second relay electrode 20: Conductive member 21: First member 211: First island portion 211A: First mounting surface 212: First hanging lead part 212A: Covering part 212B:Exposed part 213:Through hole 22: Second member 221: Second island portion 221A: Second mounting surface 222: Second suspension lead part 222A: Covered part 222B: Exposed part 31: 1st terminal 31A: 1st intermediate terminal 31B: First side terminal 311: Covering portion 312:Exposed part 32:Second terminal 32A: 2nd intermediate terminal 32B: 2nd side terminal 321: Covered part 322: Exposed part 33: Metal layer 41: First wire 42: Second wire 43: Third wire 44: 4th wire 45: 5th wire 46: 6th wire 50: Sealing resin 50A: Base material 50B: Filler 50C: Interface 51: Top surface 52: Bottom 53: First side 531: 1st upper part 532: 1st lower part 533: First middle part 54: Second side 541: 2nd upper part 542: 2nd lower part 543: 2nd intermediate part Pmin: Minimum interval D: Particle size S: Square cross section P: Spacing z: Thickness direction x: 1st direction y: 2nd direction

Claims

1. a plurality of conductive members including a first member and a second member; a first semiconductor element electrically connected to any one of the plurality of conductive members; a second semiconductor element that is electrically connected to any one of the plurality of conductive members and to which a voltage relatively different from the voltage applied to the first semiconductor element is applied; a sealing resin that covers a portion of each of the plurality of conductive members, the first semiconductor element, and the second semiconductor element; the sealing resin contains an electrically insulating filler, Assuming that the sealing resin has a square cross section with a side length equal to 2 / 3 of the minimum distance between two adjacent conductive members among the plurality of conductive members, The semiconductor device includes at least a plurality of the fillers in the square cross section, each having a particle size equal to or greater than 1 / 8 of the minimum spacing.

2. The semiconductor device according to claim 1 , wherein the voltage applied to the second member is relatively different from the voltage applied to the first member.

3. 2. The semiconductor device according to claim 1, wherein said square cross section contains at least eight or more of said fillers, each having a particle size equal to or greater than 1 / 8 of said minimum spacing.

4. 4. The semiconductor device according to claim 3, wherein the maximum particle size of said filler is half of said minimum interval.

5. the first member and the second member are spaced apart from each other in a first direction perpendicular to a thickness direction of each of the first semiconductor element and the second semiconductor element, the first semiconductor element is mounted on the first member, the second semiconductor element is mounted on the second member, The semiconductor device according to claim 4 , wherein the distance between the first member and the second member is not less than 1.0 times and not more than 3.0 times the minimum distance.

6. the first semiconductor element is electrically connected to the first member; The semiconductor device according to claim 5 , wherein the second semiconductor element is electrically connected to the second member.

7. the plurality of conductive members include a plurality of first terminals located on one side in the first direction and a plurality of second terminals located on the other side in the first direction, the first semiconductor element is electrically connected to the first terminals; the second semiconductor element is electrically connected to the second terminals; 7. The semiconductor device according to claim 5, wherein the plurality of first terminals and the plurality of second terminals are arranged along a second direction perpendicular to the first direction.

8. the first member has a first island portion on which the first semiconductor element is mounted, and two first suspension lead portions connected to both sides of the first island portion in the second direction, the second member has a second island portion on which the second semiconductor element is mounted, and two second suspension lead portions connected to both sides of the second island portion in the second direction, the two first suspension lead portions are exposed from one side of the sealing resin in the first direction, The semiconductor device according to claim 7 , wherein the two second suspension lead portions are exposed from the other side of the sealing resin in the first direction.

9. The semiconductor device according to claim 8 , wherein the second island portion overlaps the first island portion when viewed in the first direction.

10. an insulating element that relays mutual signals between the first semiconductor element and the second semiconductor element and insulates the first semiconductor element and the second semiconductor element from each other; 10. The semiconductor device according to claim 5, wherein the insulating element is an inductive type.

11. The semiconductor device according to claim 10 , wherein the insulating element is mounted on the first member.

12. The semiconductor device according to claim 10 , wherein the insulating element is mounted on the second member.

13. Further comprising a first wire and a second wire; the first wire is bonded to the insulating element and the first semiconductor element; the second wire is bonded to the insulating element and the second semiconductor element; 13. The semiconductor device according to claim 10, wherein the first wire and the second wire each contain gold.

14. 14. The semiconductor device according to claim 1, wherein the filler contains silicon dioxide.

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