JP2023078915A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

To improve heat radiation property while preventing solder from coming into contact with a pad and bonding wire.SOLUTION: A semiconductor element 40 has an emitter electrode 42 and a pad 44 on one surface, and a collector electrode 43 on a rear surface. A wiring member 50 is connected to the emitter electrode 42 via a conductive spacer 70. A wiring member 60 is connected to the collector electrode 43. The pad 44 is connected to a signal terminal 83 via bonding wire 90. The conductive spacer 70 has a recess 71 arranged on a part of a counter face 70b to the semiconductor element 40. The recess 71 opens at a part of side faces 70c, 70d, 70e, and 70f except parts facing the pad 44 in an aligning direction of the emitter electrode 42 and the pad 44.SELECTED DRAWING: Figure 3

Description

The disclosure in this specification relates to a semiconductor device and a manufacturing method thereof.

Patent Document 1 discloses a semiconductor device having a double-sided heat dissipation structure. A semiconductor element has an emitter electrode and a pad on one surface and a collector electrode on the back surface. A first heat sink is electrically connected to the emitter electrode, and a second heat sink is electrically connected to the collector electrode. These heat sinks are arranged so as to sandwich the semiconductor element therebetween. A signal terminal is connected to the pad via a bonding wire. A conductive spacer (terminal) is interposed between the semiconductor element and the first heat sink to avoid contact between the bonding wires and the first heat sink. The contents of the prior art documents are incorporated by reference as descriptions of technical elements in this specification.

JP 2016-197706 A

With conductive spacers, solder is disposed between the emitter electrode and the conductive spacer and between the conductive spacer and the first heat sink, respectively. Solder has a low thermal conductivity compared to the conductive spacer and the first heat sink. In the heat transfer path from the semiconductor element to the first heat sink provided with two layers of solder, it is important to control the solder to improve heat dissipation.

Semiconductor devices with conductive spacers are formed through the formation of connectors, wire connections, and reflow. First, a connecting body of the second heat sink, the semiconductor element, and the conductive spacer is formed. Next, the signal terminals and the pads of the semiconductor element are connected by bonding wires. Then, reflow is performed to connect the conductive spacer and the first heat sink.

The reflow also melts the solder between the conductive spacer and the emitter electrode (on-device solder). Therefore, if there is a large amount of solder on the element, the melted solder on the element is pushed by the weight of other elements located above it and overflows from between the opposed surfaces of the conductive spacer and the emitter electrode, causing the overflowed solder to flow. There is a risk of contact with pads and bonding wires. In view of the above or in other aspects not mentioned, semiconductor devices are desired to be further improved.

The present disclosure has been made in view of such problems, and an object of the present disclosure is to provide a semiconductor device capable of improving heat dissipation while suppressing contact of solder with pads and bonding wires, and a method of manufacturing the same.

The semiconductor device disclosed herein is
A semiconductor element having a first main electrode (42) and a signal pad (44) on one surface (41a) and a second main electrode (43) on the back surface (41b) opposite to the one surface in the plate thickness direction ( 40) and
a first wiring member (50) electrically connected to the first main electrode;
a second wiring member (60) disposed so as to sandwich the semiconductor element between itself and the first wiring member in the plate thickness direction and electrically connected to the second main electrode;
a signal terminal (83) electrically connected to the pad via a bonding wire (90);
a conductive spacer (70) interposed between the semiconductor element and the first wiring member;
Solders (91, 92, 93) disposed between the second wiring member and the second main electrode, between the first main electrode and the conductive spacer, and between the conductive spacer and the first wiring member, respectively;
with
The conductive spacer is provided on a portion of the surface (70b) facing the semiconductor element, and is opened in a portion of the side surface contiguous to the facing surface, excluding the portion facing the pad in the direction in which the first main electrode and the pad are arranged. It has a recess (71).

According to the disclosed semiconductor device, when a large amount of solder is placed between the first main electrode and the conductive spacer, the melted solder can be accommodated in the recess. The recess is open in a portion of the side surface of the conductive spacer excluding the portion facing the pad. This can prevent the solder from contacting the pads and bonding wires. Moreover, heat dissipation can be improved as compared with the configuration in which the side surface is opened all around. As described above, heat dissipation can be improved while suppressing contact of solder with pads and bonding wires.

The manufacturing method of the semiconductor device disclosed herein comprises:
A semiconductor element having a first main electrode (42) and a signal pad (44) on one surface (41a) and a second main electrode (43) on the back surface (41b) opposite to the one surface in the plate thickness direction ( 40), providing a first wiring member (50), a second wiring member (60), a signal terminal (83), and a conductive spacer (70);
Molten solder (91, 92, 93) to form a connection body (100) in which the second wiring member, the semiconductor element, and the conductive spacer are laminated in the plate thickness direction;
connecting a pad of a semiconductor element forming a connecting body and a signal terminal with a bonding wire (90);
connecting the conductive spacer and the first wiring member by stacking the first wiring member and the connector after connecting the bonding wires and performing reflow;
with
A concave portion (71) provided in a part of the surface (70b) facing the semiconductor element and opening in a portion of the side surface contiguous to the facing surface, excluding the portion facing the pad in the direction in which the first main electrode and the pad are arranged. Prepare a conductive spacer with

According to the disclosed method for manufacturing a semiconductor device, when a large amount of molten solder is disposed between the first main electrode and the conductive spacer, the molten solder can be accommodated in the recess. The recess is open in a portion of the side surface of the conductive spacer excluding the portion facing the pad. Therefore, it is possible to prevent the solder from contacting the pads and bonding wires. Moreover, heat dissipation can be improved as compared with the configuration in which the side surface is opened all around. As described above, heat dissipation can be improved while suppressing contact of solder with pads and bonding wires.

The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. Reference numerals in parentheses described in the claims and this section are intended to exemplify the correspondence with portions of the embodiments described later, and are not intended to limit the technical scope. Objects, features, and advantages disclosed in this specification will become clearer with reference to the following detailed description and accompanying drawings.

1 is a diagram showing a schematic configuration of a vehicle drive system to which a semiconductor device according to a first embodiment is applied; FIG. 1 is a plan view showing a semiconductor device according to a first embodiment; FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2; FIG. 3 is a cross-sectional view taken along line IV-IV of FIG. 2; FIG. FIG. 4 is a plan view showing a semiconductor element and conductive spacers; FIG. 4 is a perspective view showing a conductive spacer; It is sectional drawing which shows a manufacturing process. It is sectional drawing which shows a manufacturing process. It is sectional drawing which shows a manufacturing process. It is a perspective view which shows a modification. It is a perspective view which shows a modification. FIG. 10 is a perspective view showing a conductive spacer in the semiconductor device according to the second embodiment; FIG. 11 is a perspective view showing a conductive spacer in a semiconductor device according to a third embodiment; FIG. 11 is a plan view showing a semiconductor element and conductive spacers in a semiconductor device according to a fourth embodiment; FIG. 4 is a perspective view showing a conductive spacer; It is a top view which shows a modification. It is a perspective view which shows a modification.

A plurality of embodiments will be described below based on the drawings. Note that redundant description may be omitted by assigning the same reference numerals to corresponding components in each embodiment. When only a part of the configuration is described in each embodiment, the configurations of other embodiments previously described can be applied to other portions of the configuration. In addition, not only the combinations of the configurations specified in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined even if they are not specified unless there is a particular problem with the combination. .

The semiconductor device of the present embodiment is applied, for example, to a power conversion device for a moving object that uses a rotating electrical machine as a drive source. Examples of mobile objects include electric vehicles such as electric vehicles (EV), hybrid vehicles (HV), and plug-in hybrid vehicles (PHV), flying vehicles such as electric vertical takeoff and landing aircraft and drones, ships, construction machinery, and agricultural machinery. . An example applied to a vehicle will be described below.

(First embodiment)
First, based on FIG. 1, a schematic configuration of a vehicle drive system will be described.

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

The DC power supply 2 is a DC voltage source composed of a rechargeable secondary battery. Secondary batteries are, for example, lithium ion batteries and nickel metal hydride batteries. The motor generator 3 is a three-phase alternating-current rotating electric machine. The motor generator 3 functions as a vehicle drive source, that is, as an electric motor. The motor generator 3 functions as a generator during regeneration. The power converter 4 performs power conversion between the DC power supply 2 and the motor generator 3 .

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

Smoothing capacitor 5 mainly smoothes the DC voltage supplied from DC power supply 2 . The smoothing capacitor 5 is connected to a P line 7 that is a power line on the high potential side and an N line 8 that is a power line on the low potential side. The P line 7 is connected to the positive pole of the DC power supply 2 and the N line 8 is connected to the negative pole of the DC power supply 2 . The positive terminal of smoothing capacitor 5 is connected to P line 7 between DC power supply 2 and inverter 6 . Similarly, the negative pole is connected to the N line 8 between the DC power supply 2 and the inverter 6 . A smoothing capacitor 5 is connected in parallel with the DC power supply 2 .

The inverter 6 is a DC-AC conversion circuit. Inverter 6 converts the DC voltage into a three-phase AC voltage and outputs it to motor generator 3 according to switching control by a control circuit (not shown). Thereby, the motor generator 3 is driven to generate a predetermined torque. During regenerative braking of the vehicle, inverter 6 converts the three-phase AC voltage generated by motor generator 3 in response to the torque from the wheels into DC voltage according to switching control by the control circuit, and outputs the DC voltage to P line 7 . Thus, inverter 6 performs bidirectional power conversion between DC power supply 2 and motor generator 3 .

The inverter 6 is configured with upper and lower arm circuits 9 for three phases. The upper and lower arm circuits 9 are sometimes called legs. The upper and lower arm circuits 9 each have an upper arm 9H and a lower arm 9L. The upper arm 9H and the lower arm 9L are connected in series between the P line 7 and the N line 8 with the upper arm 9H on the P line 7 side. A connection point between the upper arm 9</b>H and the lower arm 9</b>L is connected to a corresponding phase winding 3 a in the motor generator 3 via an output line 10 . Inverter 6 has six arms. At least part of each of P line 7, N line 8 and output line 10 is formed of a conductive member such as a bus bar.

Elements forming each arm include an insulated gate bipolar transistor 11 (hereinafter referred to as IGBT 11) as a switching element and a freewheeling diode 12. FIG. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. In this embodiment, an n-channel type IGBT 11 is adopted. Diode 12 is connected in anti-parallel with corresponding IGBT 11 . The collector of the IGBT 11 is connected to the P line 7 in the upper arm 9H. The emitter of the IGBT 11 is connected to the N line 8 in the lower arm 9L. The emitter of the IGBT 11 on the upper arm 9H and the collector of the IGBT 11 on the lower arm 9L are connected to each other. The anode of diode 12 is connected to the emitter of corresponding IGBT 11, and the cathode is connected to the collector.

The power conversion device 4 may further include a converter as a power conversion circuit. A converter is a DC-DC conversion circuit that converts a DC voltage into DC voltages of different values. The converter is provided between the DC power supply 2 and the smoothing capacitor 5 . The converter includes, for example, a reactor and the upper and lower arm circuits 9 described above. According to this configuration, it is possible to step up and down. The power conversion device 4 may include a filter capacitor that removes power noise from the DC power supply 2 . A filter capacitor is provided between the DC power supply 2 and the converter.

The power conversion device 4 may include a drive circuit for switching elements forming the inverter 6 and the like. A drive circuit supplies a drive voltage to the gate of IGBT11 of a corresponding arm based on the drive command of a control circuit. The drive circuit drives the corresponding IGBT 11 by applying a drive voltage, that is, turns it on and off. A driving circuit is sometimes referred to as a driver.

The power conversion device 4 may include a control circuit for switching elements. The control circuit generates a drive command for operating the IGBT 11 and outputs it to the drive circuit. The control circuit generates a drive command based on a torque request input from a host ECU (not shown) and signals detected by various sensors. Various sensors include, for example, a current sensor, a rotation angle sensor, and a voltage sensor. The current sensor detects a phase current flowing through each phase winding 3a. The rotation angle sensor detects the rotation angle of the rotor of motor generator 3 . A voltage sensor detects the voltage across the smoothing capacitor 5 . The control circuit outputs, for example, a PWM signal as the drive command. The control circuit comprises, for example, a processor and memory. ECU is an abbreviation for Electronic Control Unit. PWM is an abbreviation for Pulse Width Modulation.

<Semiconductor device>
Next, a schematic configuration of the semiconductor device will be described with reference to FIGS. 2 to 5. FIG. FIG. 2 is a plan view showing the semiconductor device. FIG. 2 is a top plan view of the semiconductor device. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2. FIG. FIG. 5 is a plan view showing the arrangement of semiconductor elements, conductive spacers, and signal terminals in a semiconductor device.

Hereinafter, the plate thickness direction of the semiconductor element (semiconductor substrate) is defined as the Z direction. One direction perpendicular to the Z direction is defined as the X direction. A direction perpendicular to both the Z direction and the X direction is defined as the Y direction. Unless otherwise specified, a planar shape is defined as a planar shape viewed from the Z direction, in other words, a planar shape along the XY plane defined by the X and Y directions. Also, a planar view from the Z direction may simply be referred to as a planar view.

As shown in FIGS. 2 to 4, the semiconductor device 20 includes a sealing body 30, a semiconductor element 40, wiring members 50 and 60, conductive spacers 70, and external connection terminals . The semiconductor device 20 further includes bonding wires 90 and solders 91-93. The semiconductor device 20 constitutes one of the arms described above. That is, two semiconductor devices 20 constitute the upper and lower arm circuits 9 for one phase.

The encapsulant 30 encapsulates a part of other elements that constitute the semiconductor device 20 . The rest of the other elements are exposed outside the encapsulant 30 . Sealing body 30 is made of resin, for example. An example of the resin is an epoxy resin. The sealing body 30 is made of resin and is molded by, for example, a transfer molding method. Such a sealing body 30 is sometimes referred to as a sealing resin body, mold resin, resin molded body, or the like. Sealing body 30 may be formed using gel, for example. The gel is filled (arranged) in, for example, opposing regions of the pair of wiring members 50 and 60 .

As shown in FIGS. 2 to 4, the sealing body 30 has a substantially rectangular planar shape. The sealing body 30 has one surface 30a and a back surface 30b opposite to the one surface 30a in the Z direction as surfaces forming an outline. One surface 30a and back surface 30b are, for example, substantially flat surfaces. It also has side surfaces 30c, 30d, 30e, and 30f that are continuous with the one surface 30a and the back surface 30b. The side surface 30c is a surface from which the main terminals 81 and 82 of the external connection terminal 80 protrude. The side surface 30d is a surface opposite to the side surface 30c in the Y direction. The side surface 30d is a surface from which the signal terminal 83 protrudes. The side surfaces 30e and 30f are surfaces from which the external connection terminals 80 do not protrude. The side surface 30e is a surface opposite to the side surface 30f in the X direction.

The semiconductor element 40 has a switching element formed on a semiconductor substrate 41 made of silicon (Si), a wide bandgap semiconductor having a wider bandgap than silicon, or the like. Wide bandgap semiconductors include, for example, silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga ₂ O ₃ ), and diamond. The semiconductor element 40 may be called a power element, a semiconductor chip, or the like.

The semiconductor element 40 of this embodiment is formed by forming the above-described n-channel IGBT 11 and diode 12 on a semiconductor substrate 41 . The IGBT 11 and the diode 12 have a vertical structure so that the main current flows in the plate thickness direction of the semiconductor element 40 (semiconductor substrate 41), that is, in the Z direction. Thus, RC (Reverse Conducting)-IGBTs are formed on the semiconductor substrate 41 . The semiconductor element 40 is a heating element that generates heat when energized. A gate electrode (not shown) is formed on the semiconductor substrate 41 . The gate electrode has, for example, a trench structure.

In addition to the semiconductor substrate 41 described above, the semiconductor element 40 has an emitter electrode 42 and a collector electrode 43 as main electrodes, and a pad 44 as a signal electrode. The semiconductor substrate 41 has one surface 41a and a back surface 41b as plate surfaces on which main electrodes are provided. The one surface 41 a is the surface of the semiconductor substrate 41 on the side of the one surface 30 a of the sealing body 30 . The back surface 41b is a surface opposite to the one surface 41a in the plate thickness direction. An emitter electrode 42 , which is one of the main electrodes, is arranged on one surface 41 a of the semiconductor substrate 41 . A collector electrode 43 , which is another one of the main electrodes, is arranged on the back surface 41 b of the semiconductor substrate 41 . The emitter electrode 42 corresponds to the first main electrode, and the collector electrode 43 corresponds to the second main electrode.

When the IGBT 11 is turned on, current (main current) flows between the main electrodes, that is, between the emitter electrode 42 and the collector electrode 43 . The emitter electrode 42 also serves as the anode electrode of the diode 12 . The collector electrode 43 also serves as the cathode electrode of the diode 12 . The collector electrode 43 is formed almost entirely on the back surface 41 b of the semiconductor substrate 41 . Emitter electrode 42 is formed on a portion of one surface 41 a of semiconductor substrate 41 .

The pad 44 is formed in a region different from the forming region of the emitter electrode 42 on the one surface 41 a of the semiconductor substrate 41 . The pad 44 is formed at the end opposite to the forming region of the emitter electrode 42 in the Y direction. The pad 44 is provided side by side with the emitter electrode 42 in the Y direction. The number of pads 44 is not particularly limited. The pads 44 include at least pads for gate electrodes. The semiconductor element 40 of this embodiment has five pads 44 . Specifically, it has a gate electrode, an emitter potential detection, a cathode potential detection of a temperature-sensitive diode (not shown) provided in the semiconductor element 40, an anode potential detection, and a current sensing. The five pads 44 are arranged along the X direction.

The wiring member 50 is electrically connected to the emitter electrode 42 and provides a wiring function. Similarly, wiring member 60 is electrically connected to collector electrode 43 and provides a wiring function. The wiring members 50 and 60 are arranged so as to sandwich the semiconductor element 40 in the Z direction. The wiring members 50 and 60 are arranged so that at least parts of them face each other in the Z direction. The wiring members 50 and 60 enclose the semiconductor element 40 in plan view. The wiring member 50 corresponds to the first wiring member, and the wiring member 60 corresponds to the second wiring member.

The wiring members 50 and 60 provide a heat dissipation function for dissipating heat generated by the semiconductor element 40 . The wiring members 50 and 60 are sometimes called a radiator plate, a heat sink, or the like. The wiring members 50 and 60 of the present embodiment are metal plates made of metal with good conductivity such as Cu and Cu alloys. A metal plate is provided, for example, as part of a lead frame. Instead of the metal plate, a substrate in which metal bodies are arranged on both sides of an insulating base material may be employed. The wiring members 50 and 60 may have a plated film of Ni, Au, or the like on the surface.

The wiring member 50 has a facing surface 50a, which is the surface on the semiconductor element 40 side, and a back surface 50b, which is the surface opposite to the facing surface 50a. Similarly, the wiring member 60 also has a facing surface 60a and a back surface 60b. The wiring members 50 and 60 are, for example, substantially rectangular in plan view. Rear surfaces 50 b and 60 b of the wiring members 50 and 60 are exposed from the sealing body 30 . The back surfaces 50b and 60b are sometimes referred to as heat dissipation surfaces, exposed surfaces, and the like. The back surface 50 b of the wiring member 50 is substantially flush with the one surface 30 a of the sealing body 30 . The back surface 60 b of the wiring member 60 is substantially flush with the back surface 30 b of the sealing body 30 .

A conductive spacer 70 is interposed between the semiconductor element 40 and the wiring member 50 . The conductive spacer 70 provides a spacer function of ensuring a predetermined distance between the semiconductor element 40 and the wiring member 50 . For example, conductive spacers 70 provide height for electrically connecting corresponding signal terminals 83 to pads 44 of semiconductor element 40 . The conductive spacer 70 is located in the middle of the electrical and thermal conduction path between the emitter electrode 42 of the semiconductor element 40 and the wiring member 50, and provides a wiring function and a heat dissipation function.

The conductive spacer 70 contains a metal material such as Cu that has good electrical and thermal conductivity. The conductive spacer 70 may have a plated film on its surface. Conductive spacers 70 are sometimes referred to as terminals, terminal blocks, metal blocks, and the like. The conductive spacer 70 of this embodiment is a columnar body having a substantially rectangular planar shape.

The external connection terminal 80 is a terminal for electrically connecting the semiconductor device 20 to an external device. The external connection terminal 80 is formed using a metal material with good conductivity such as copper. The external connection terminal 80 is, for example, a plate material. The external connection terminals 80 are sometimes called leads. The external connection terminal 80 includes main terminals 81 and 82 and a signal terminal 83 . The main terminals 81 and 82 are external connection terminals 80 electrically connected to the main electrodes of the semiconductor element 40 .

The main terminal 81 is electrically connected to the emitter electrode 42 . Main terminal 81 is sometimes referred to as an emitter terminal. The main terminal 81 is connected to the emitter electrode 42 via the wiring member 50 . The main terminal 81 is connected to one end of the wiring member 50 in the Y direction. The thickness of the main terminal 81 is thinner than that of the wiring member 50 . The main terminal 81 continues to the wiring member 50 so as to be substantially flush with the facing surface 50a, for example. The main terminal 81 may be connected to the wiring member 50 by being continuously provided integrally therewith, or may be provided as a separate member and connected to the wiring member 50 by joining.

The main terminal 81 of this embodiment is provided integrally with the wiring member 50 as part of the lead frame. The main terminal 81 extends in the Y direction from the wiring member 50 and protrudes outside from the side surface 30 c of the sealing body 30 . The main terminal 81 has a bent portion in the middle of the portion covered with the sealing body 30, and protrudes from the vicinity of the center in the Z direction on the side surface 30c.

The main terminal 82 is electrically connected to the collector electrode 43 . Main terminal 82 is sometimes referred to as a collector terminal. The main terminal 82 is connected to the collector electrode 43 via the wiring member 60 . The main terminal 82 continues to one end of the wiring member 60 in the Y direction. The thickness of the main terminal 82 is thinner than that of the wiring member 60 . The main terminal 82 is connected to the wiring member 60 so as to be substantially flush with the facing surface 60a, for example. The main terminal 82 may be connected to the wiring member 60 by being integrally provided continuously, or may be provided as a separate member and connected to the wiring member 60 by joining.

The main terminal 82 of this embodiment is provided integrally with the wiring member 60 as part of a lead frame different from the main terminal 81 . The main terminal 82 extends in the Y direction from the wiring member 60 and protrudes outside from the same side surface 30 c as the main terminal 81 . The main terminal 82 also has a bent portion in the middle of the portion covered with the sealing body 30, and protrudes from the vicinity of the center in the Z direction on the side surface 30c. The two main terminals 81 and 82 are arranged side by side in the X direction so that their side surfaces face each other.

Signal terminals 83 are electrically connected to corresponding pads 44 of semiconductor element 40 . Signal terminal 83 is electrically connected to pad 44 via bonding wire 90 . The signal terminal 83 extends in the Y direction and protrudes outside from the side surface 30 d of the sealing body 30 . The semiconductor device 20 of this embodiment has five signal terminals 83 corresponding to the pads 44 . The five signal terminals 83 are arranged side by side in the X direction. The signal terminal 83 is configured on a lead frame common to the wiring member 60 and the main terminal 82, for example. The plurality of signal terminals 83 are electrically isolated from each other by cutting tie bars (not shown).

Solder 91 is interposed between the emitter electrode 42 of the semiconductor element 40 and the conductive spacer 70 to join the emitter electrode 42 and the conductive spacer 70 together. The solder 91 is sometimes referred to as on-device solder. The solder 92 is interposed between the conductive spacer 70 and the wiring member 50 to join the conductive spacer 70 and the wiring member 50 together. Solder 92 is sometimes referred to as solder on spacers. The solder 93 is interposed between the collector electrode 43 of the semiconductor element 40 and the wiring member 60 to join the collector electrode 43 and the wiring member 60 together. The solder 93 is sometimes referred to as under-element solder. The solders 91 to 93 may use a common material or may use different materials. The solders 91 to 93 are multicomponent lead-free solders containing, for example, Sb, Bi, etc. in addition to Sn.

As described above, in the semiconductor device 20 , the semiconductor element 40 forming one arm is sealed with the sealing body 30 . The sealing body 30 integrally seals the semiconductor element 40 , part of the wiring member 50 , part of the wiring member 60 , conductive spacer 70 , and part of the external connection terminals 80 .

The semiconductor element 40 is arranged between the wiring members 50 and 60 in the Z direction. The semiconductor element 40 is sandwiched between wiring members 50 and 60 arranged opposite to each other. Thereby, the heat of the semiconductor element 40 can be dissipated to both sides in the Z direction. The semiconductor device 20 has a double-sided heat dissipation structure. The back surface 50 b of the wiring member 50 is substantially flush with the one surface 30 a of the sealing body 30 . The back surface 60 b of the wiring member 60 is substantially flush with the back surface 30 b of the sealing body 30 . Since the back surfaces 50b and 60b are exposed surfaces, heat dissipation can be enhanced.

<Conductive spacer>
Next, the structure of the conductive spacer 70 will be described with reference to FIGS. 3 to 6. FIG. FIG. 6 is a perspective view showing the conductive spacer 70. FIG.

As described above, the conductive spacer 70 of this embodiment has a substantially rectangular planar shape. The conductive spacer 70 has opposing surfaces 70a and 70b and side surfaces 70c, 70d, 70e and 70f as surfaces forming an outline. The facing surface 70a is a surface opposite to the facing surface 70b in the Z direction. In the Z direction, the opposing surface 70a faces the wiring member 50, and the opposing surface 70b faces the semiconductor element 40 (emitter electrode 42).

The side surfaces 70c, 70d, 70e, and 70f are surfaces connected to the opposing surfaces 70a and 70b. The side surface 70c is a surface opposite to the side surface 70d in the Y direction. In the Y direction, the side surface 70c is located on the side surface 30c side of the sealing body 30, and the side surface 70d is located on the side surface 30d side. The side surface 70e is a surface opposite to the side surface 70f in the X direction. In the X direction, the side surface 70e is located on the side surface 30e side of the sealing body 30, and the side surface 70f is located on the side surface 30f side. The side surface 70d corresponds to the first side surface, and the side surface 70c corresponds to the second side surface. One of the side surfaces 70e and 70d corresponds to the third side surface, and the other one corresponds to the fourth side surface.

Conductive spacer 70 has recess 71 . The recess 71 is provided in a part of the facing surface 70b. The recess 71 is recessed with respect to other portions of the facing surface 70b. The recess 71 is open in at least one of the side surfaces 70c, 70e, and 70f except for the side surface 70d including the portion facing the pad 44 in the Y direction. The recess 71 of this embodiment is open to the side surfaces 70c, 70e, and 70f. The recess 71 is continuously open over the side surfaces 70c, 70e, and 70f. When there are a plurality of pads 44 , the portion facing the pads 44 is the portion facing the forming region of the plurality of pads 44 . The forming region of the plurality of pads 44 is a portion where the contours of the plurality of pads 44 are connected so as to surround the plurality of pads 44 in plan view. In the present embodiment, the forming area of the plurality of pads 44 is longer than the side surface 70d in the X direction, and faces the pads 44 over the entire length of the side surface 70d.

The recess 71 is a chamfer provided at the corner between the facing surface 70b and the side surface 70c. The chamfered portion is, for example, a C chamfer with a chamfering angle of approximately 45 degrees. The recessed portion 71 extends along the X direction, and has one end opening to the side surface 70e and the other end opening to the side surface 70f. The length of the recess 71 in the Y direction, that is, the width, is shorter than the length in the X direction, which is the extension direction. The opening area on the side surface 70c is larger than the opening area on the side surface 70e and the opening area on the side surface 70f. The recess 71 opens to the side surfaces 70e and 70f at a position away from the side surface 70d. The length of the recess 71 in the Z direction, that is, the depth, is about half the length of the side surface 70c. Such a concave portion 71 can be formed, for example, by pressing or cutting.

The conductive spacers 70 may have low-wetting areas of solder on the sides. For example, an uneven oxide film may be provided. The uneven oxide film is formed by irradiating the plated film of the conductive spacer 70 with a laser beam. The uneven oxide film provides a high wettability region in the portion where the uneven oxide film is not provided, that is, the portion of the plated film, and the low wettability in the portion provided with the uneven oxide film, which is lower than the high wettability region. provide territory. Although illustration is omitted, in this embodiment, an uneven oxide film (low wettability region) is provided on almost the entire side surface.

By providing the low wettability region on the side surface, the wetting and spreading of the solder through the side surface of the conductive spacer 70 can be suppressed. Note that the low wettability region is not limited to the uneven oxide film. By providing the resin film, wettability may be made lower than that of the portion where the resin film is to be provided. Of course, the structure may be such that the low wettability region is not provided on the side surface.

<Manufacturing method>
Next, a method for manufacturing the semiconductor device 20 will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 is a cross-sectional view showing a step of forming a connecting body. FIG. 8 is a cross-sectional view showing the reflow process.

First, each element constituting the semiconductor device 20 is prepared. Specifically, the semiconductor element 40, the wiring members 50 and 60, the conductive spacers 70, and the external connection terminals 80 are prepared. At this time, the conductive spacer 70 having the concave portion 71 described above is prepared.

Molten solder is then applied to form connections. A molten solder (solder 93) is placed between the wiring member 60 and the collector electrode 43 of the semiconductor element 40, and a molten solder (solder 91) is placed between the emitter electrode 42 and the conductive spacer . Further, molten solder (solder 92) is placed on the facing surface 70a of the conductive spacer 70. Then, as shown in FIG. By solidifying (solidifying) the molten solder, as shown in FIG. 7, the semiconductor element 40, the wiring member 60, and the conductive spacer 70 are laminated to obtain the connecting body 100 integrally connected.

Molten solder can be applied, for example, using a transfer method. For example, molten solder (93) is applied to the facing surface 60a of the wiring member 60. As shown in FIG. Molten solder (solder 91) is applied to the facing surface 70b of the conductive spacer 70, and molten solder (solder 92) is applied to the facing surface 70a of the conductive spacer 70. FIG. Thus, in this embodiment, the semiconductor device 20 is formed using the solder die bonding method.

The semiconductor device 20 having a double-sided heat dissipation structure is sandwiched from both sides in the Z direction by coolers (not shown), for example. Therefore, high parallelism of the surfaces in the Z direction and high dimensional accuracy between the surfaces are required. Therefore, the solder 92 is arranged in an amount capable of absorbing the height variation of the semiconductor device 20 . That is, a large amount of solder 92 is arranged.

Next, although illustration is omitted, the pads 44 of the semiconductor element 40 and the signal terminals 83 are connected by bonding wires 90 .

Next, the wiring member 50 and the conductive spacer 70 are connected by reflow. For example, the wiring member 50 is arranged on the pedestal 110 so that the facing surface 50a faces upward. Then, the connection body 100 is stacked on the wiring member 50 so that the solder 92 faces the facing surface 50a of the wiring member 50, and reflow is performed. In the reflow, a load is applied in the Z direction from the wiring member 60 side so that the height of the semiconductor device 20 reaches a predetermined height. Specifically, by applying a load, the spacer 111 having a predetermined length is brought into contact with both the facing surface 60 a of the wiring member 60 and the mounting surface of the pedestal 110 . In this manner, the height of the semiconductor device 20 is set to a predetermined height.

The position of the heat source used for solder reflow is not particularly limited. A heat source (not shown) is arranged, for example, on the side of the pedestal 110 opposite to the mounting surface. In this arrangement, heat from the heat source is transmitted to the solder 92 via the base 110 and the wiring member 50 .

The solder 92 is melted by the heat from the heat source, and the wiring member 50 and the conductive spacer 70 are connected (bonded). That is, the emitter electrode 42 and the wiring member 50 are electrically connected. Heat from the heat source is also transmitted to the solder 91 via the conductive spacer 70 . Thereby, the solder 91 is also melted. Similarly, solder 93 may also be melted.

Next, a sealing body 30 is formed. Although illustration is omitted, in the present embodiment, the sealing body 30 is molded by a transfer molding method. The encapsulant 30 is molded so as to completely cover the wiring members 50 and 60, and is cut after molding. The encapsulant 30 is cut along with a part of the wiring members 50 and 60 . Thereby, the rear surfaces 50b and 60b are exposed. The back surface 50b is substantially flush with the one surface 30a, and the back surface 60b is substantially flush with the back surface 30b.

Note that the sealing body 30 may be molded in a state in which the back surfaces 50b and 60b are pressed against the wall surface of the cavity of the molding die so as to be in close contact with each other. In this case, the rear surfaces 50b and 60b are exposed from the sealing body 30 when the sealing body 30 is molded. This eliminates the need for cutting after molding.

Then, the semiconductor device 20 can be obtained by removing the unnecessary portions of the lead frame such as the tie bars and the outer peripheral frame.

<Summary of the first embodiment>
If a large amount of solder (on-element solder) is disposed between the semiconductor element and the conductive spacer, the on-element solder melted in the reflow process may be deposited on the element (for example, the second wiring member) located above the on-element solder. There is a risk of overflow from the opposing region between the emitter electrode and the conductive spacer due to the weight of the . The overflowing solder on the element contacts (adheres to) pads and bonding wires, and causes short circuits between pads, connections between pads and signal terminals that do not correspond to each other, increased thermal stress, reduced adhesion of the sealing body 30, and the like. cause.

In the process of forming a connecting body comprising a second wiring member, a semiconductor element, and a conductive spacer, when molten solder is applied (solder die bonding), variations in the amount of solder occur compared to a configuration in which metal foil is arranged and reflowed. growing. Therefore, melted solder on the element tends to overflow in the reflow process.

In this embodiment, recesses 71 are provided in part of the facing surface 70b of the conductive spacer 70. As shown in FIG. When the amount of solder 91 (solder on the element) is large due to variations in the amount of application, the solder 91 melted in the reflow process can be accommodated in the recess 71 as shown in FIG. This can prevent the solder 91 from contacting the pads 44 and the bonding wires 90 . FIG. 9 is a cross-sectional view showing the reflow process, which corresponds to the region IX indicated by the one-dot chain line in FIG.

The concave portion 71 is open in a portion of the side surface of the conductive spacer 70 excluding the portion facing the pad 44 in the direction in which the emitter electrode 42 and the pad 44 are arranged (Y direction). Specifically, at least one of the side surfaces 70c, 70e, and 70f is opened. The melted solder 91 tends to flow toward the wide opening area. When there is a large amount of solder 91, the solder 91 melted in the reflow process tends to flow toward the side surface where the recess 71 opens as shown in FIG. This can prevent the solder 91 from contacting the pads 44 and the bonding wires 90 .

If the recess is provided so as to open all around the side surface, although the amount of solder that can be accommodated by the recess increases, the melted solder tends to flow to the side with the larger opening area, so there is a risk that the solder will overflow in the direction of the pad. In addition, since the bottom surface of the recess is farther from the emitter electrode than the opposing surface, and the thermal conductivity of solder is lower than that of the conductive spacer and the wiring member, providing the recess around the entire periphery increases thermal resistance and reduces heat dissipation. do. In this embodiment, since the recess 71 does not open on the side surface 70 d, the solder 91 can be prevented from contacting the pads 44 and the bonding wires 90 . Moreover, heat dissipation can be improved as compared with the configuration in which the entire circumference of the side surface is open. As described above, according to the semiconductor device 20 of the present embodiment and the method for manufacturing the same, it is possible to improve heat dissipation while suppressing contact of the solder 91 with the pads 44 and the bonding wires 90 .

In this embodiment, the recess 71 opens to the side surface 70c (second side surface). Since the recess 71 is open on the side opposite to the pad 44 , contact of the solder 91 with the pad 44 and the bonding wire 90 can be more effectively suppressed. Although not shown, the recess 71 may be provided so as to open only on the side surface 70c.

In this embodiment, the recess 71 opens to the side surfaces 70c, 70e, and 70f. As a result, the amount of solder 91 that can be accommodated by the concave portion 71 can be increased. Also, the opening area of the side surface 70c is larger than the opening areas of the side surfaces 70e and 70f. The recessed portion 71 opens mainly on the side surface 70c while being open on three surfaces. Therefore, it is possible to prevent the solder 91 from contacting the pads 44 and the bonding wires 90 . Although illustration is omitted, the recesses 71 may be provided so as to open individually on the side surfaces 70c, 70e, and 70f.

In this embodiment, the recess 71 is continuously open over three sides 70c, 70e, and 70f. The recessed portion 71 is provided at the corner between the facing surface 70b and the side surface 70c, and has one end opening to the side surface 70e and the other end opening to the side surface 70f. According to this, with a simple structure, the heat dissipation can be improved while suppressing contact of the solder 91 with the pad 44 and the bonding wire 90 .

In this embodiment, the recess 71 opens to the side surfaces 70e and 70f at a position apart from the side surface 70d in the Y direction. Specifically, it is opened only on the side 70c side of the central position of the side surfaces 70e and 70f in the Y direction. As a result, it is possible to effectively prevent the solder 91 from coming into contact with the pads 44 and the bonding wires 90 while increasing the capacity of the solder 91 to be accommodated by the recesses 71 .

According to this embodiment, since the concave portion 71 is provided at the corner between the facing surface 70b and the side surface, stress concentration of the solder 91 can be reduced. Also, the thickness of the solder 91 near the conductive spacer 70 is increased in plan view. Therefore, connection reliability can be improved.

As shown in FIG. 10, an R-shaped recess 71 may be employed. This concave portion 71 can be said to be an R-shaped chamfered portion. FIG. 10 corresponds to FIG. The recess 71 is formed at the corner of the facing surface 70b and the side surface 70c of the conductive spacer 70. As shown in FIG.

As shown in FIG. 11, recesses 71 having a uniform depth may be employed. FIG. 11 corresponds to FIG. The bottom surface of the recess 71 is substantially parallel to the facing surface 70b. According to this, the amount of solder 91 to be accommodated can be further increased.

(Second embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, the recess 71 extends in the X direction. Alternatively, the recess 71 may include a portion extending in the Y direction.

FIG. 12 is a perspective view showing the conductive spacer 70 in the semiconductor device 20 of this embodiment. FIG. 12 corresponds to FIG. The conductive spacer 70 has an X-direction extending portion 711 and a Y-direction extending portion 712 . The X-direction extending portion 711 is provided at the corner of the facing surface 70b and the side surface 70c, as in the previous embodiment (see FIG. 6). The Y-direction extending portion 712 is a corner portion between the facing surface 70b and the side surface 70f, and is provided in a portion closer to the side surface 70c than the central position in the Y direction. Both the X-direction extending portion 711 and the Y-direction extending portion 712 are chamfered portions.

Thus, the recess 71 is mainly open to the side surfaces 70c and 70f. One end of the X-direction extending portion 711 is open to the side surface 70e.

<Summary of Second Embodiment>
This embodiment can also achieve the same effect as the configuration shown in the preceding embodiment. The melted solder 91 tends to flow toward the side surface 70f where the recess 71 opens. This can prevent the solder 91 from contacting the pads 44 and the bonding wires 90 . Further, since the recesses 71 are provided at the corners of the facing surface 70b and the side surface 70f, heat dissipation can be improved.

Although not shown, a Y-direction extending portion 712 may be provided at the corner between the facing surface 70b and the side surface 70e. That is, the recess 71 may be opened mainly at the side surfaces 70c, 70e, and 70f. The recess 71 may be opened mainly on the side surfaces 70c and 70e.

Although illustration is omitted, the recess 71 may be opened mainly in at least one of the side surfaces 70e and 70f. The recess 71 may open only on at least one of the side surfaces 70e and 70f. In other words, the configuration may be such that the side surfaces 70c and 70d are not opened.

Also in this embodiment, an R-shaped chamfer or a concave portion 71 having a constant depth may be employed.

(Third embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used. In the previous embodiment, conductive spacer 70 had one recess 71 . Alternatively, a configuration including a plurality of recesses 71 may be employed.

FIG. 13 is a perspective view showing the conductive spacer 70 in the semiconductor device 20 of this embodiment. FIG. 13 corresponds to FIG. The conductive spacer 70 is formed by providing a partition wall 72 to the configuration shown in FIG. The partition walls 72 are sometimes referred to as beams, ribs, or the like. The partition wall 72 continues flush with the opposing surface 70b. The partition wall 72 protrudes in the Z direction from the bottom surface of the recess 71 and extends in the Y direction from the opposing surface 70b. The conductive spacer 70 has a plurality of partition walls 72 provided at a predetermined pitch in the X direction. The partition wall 72 partitions the concave portion 71 into a plurality of portions. Each of the partitioned recesses 71 extends in the Y direction. The plurality of recesses 71 are arranged side by side in the X direction. The concave portion 71 having such a structure can be formed by cutting or etching, for example.

<Summary of Third Embodiment>
This embodiment can also achieve the same effect as the configuration shown in the preceding embodiment. Further, by leaving the partition wall 72 while increasing the amount of solder 91 to be accommodated, heat dissipation can be improved as compared with the configuration shown in FIG. Further, by providing a plurality of partition walls 72 at predetermined intervals, uneven heat dissipation can be suppressed.

The extending direction of the partition wall 72 is not limited to the Y direction. The conductive spacer 70 may be provided with a plurality of partition walls 72 extending in the X direction, for example.

(Fourth embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, an example was shown in which the recess 71 does not open on the side surface 70d. Instead of this, the concave portion 71 may be provided so as to open in a portion of the side surface 70 d that does not face the pad 44 .

FIG. 14 shows the arrangement of the semiconductor element 40 and the conductive spacers 70 in the semiconductor device 20 according to this embodiment. FIG. 14 corresponds to FIG. As shown in FIG. 14, the pads 44 of this embodiment are also arranged along the X direction. A plurality of pads 44 are provided biased toward one end side of the semiconductor element 40 in the X direction.

FIG. 15 is a perspective view showing the conductive spacer 70. FIG. FIG. 15 corresponds to FIG. As shown in FIG. 15, the recess 71 opens mainly at the side surfaces 70c and 70f. The concave portion 71 has an X-direction extending portion 711 and a Y-direction extending portion 712 . The X-direction extending portion 711 is provided at the corner of the facing surface 70b and the side surface 70c, and extends from the side surface 70e to the side surface 70f, as in the previous embodiment. The Y-direction extending portion 712 is provided at the corner between the facing surface 70b and the side surface 70f, and extends from the side surface 70c to the side surface 70d. That is, one of the ends of the concave portion 71 opens to the side surface 70d, and the other one of the ends opens to the side surface 70e. The concave portion 71 is a chamfered portion.

<Summary of the fourth embodiment>
In the present embodiment, the concave portion 71 is open in a portion of the side surface 70 d excluding the portion facing the pad 44 . According to this, it is possible to improve heat dissipation while suppressing contact of the solder 91 with the pads 44 and the bonding wires 90, as in the preceding embodiment.

Note that the arrangement of the pads 44 is not limited to the example shown in FIG. A plurality of pads 44 may be collectively arranged at one of the four corners of the semiconductor element 40 so as to face part of each of the side surfaces 70d and 70e. A plurality of pads 44 may be arranged side by side so as to form, for example, a substantially L-shaped plane. By using the conductive spacer 70 shown in FIG. 15 for such an arrangement, the heat dissipation can be improved while suppressing the contact of the solder 91 with the pad 44 and the bonding wire 90 .

FIG. 16 shows a modification of the arrangement of the pads 44. As shown in FIG. FIG. 16 corresponds to FIG. FIG. 17 shows a conductive spacer 70 suitable for the pad arrangement shown in FIG. FIG. 17 corresponds to FIG. Also in the example shown in FIG. 16, a plurality of pads 44 are arranged side by side in the X direction. A plurality of pads 44 are gathered near the center of the semiconductor element 40 in the X direction. As a result, the formation region of the pad 44 is shorter than the side surface 70d of the conductive spacer 70 in the X direction. A side surface 70 d of the conductive spacer 70 faces the pad 44 in the central region in the X direction, and does not face the pad 44 in end regions sandwiching the central region.

As shown in FIG. 17, the recess 71 opens mainly on the side surfaces 70c, 70e, and 70f. The concave portion 71 has an X-direction extending portion 711 and two Y-direction extending portions 712 . The X-direction extending portion 711 is provided at the corner of the facing surface 70b and the side surface 70c and extends from the side surface 70e to the side surface 70f. One of the Y-direction extending portions 712 is provided at the corner between the facing surface 70b and the side surface 70f and extends from the side surface 70c to the side surface 70d. Another Y-direction extending portion 712 is provided at the corner of the facing surface 70b and the side surface 70e and extends from the side surface 70c to the side surface 70d.

That is, one of the ends of the concave portion 71 opens to the side surface 70d, and the other one of the ends also opens to the side surface 70d. The concave portion 71 is a chamfered portion. In this manner, the recess 71 is open to the portion of the side surface 70 d excluding the portion facing the pad 44 . Therefore, heat dissipation can be improved while suppressing contact of the solder 91 with the pads 44 and the bonding wires 90 .

Also in this embodiment, an R-shaped chamfer or a concave portion 71 having a constant depth may be employed.

(Other embodiments)
The disclosure in this specification, drawings, etc. is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations thereon by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and/or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses omitting parts and/or elements of the embodiments. The disclosure encompasses permutations or combinations of parts and/or elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is indicated by the statements in the claims, and should be understood to include all changes within the meaning and range of equivalents to the statements in the claims.

The disclosure in the specification, drawings, etc. is not limited by the description in the claims. The disclosure in the specification, drawings, etc. encompasses the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure of the specification, drawings, etc., without being bound by the scope of claims.

When an element or layer is referred to as being "overlying," "coupled with," "connected to," or "coupled with," it refers to other elements or layers. may be coupled, connected or bonded directly on, and there may be intervening elements or layers. In contrast, an element is "directly on", "directly coupled to", "directly connected to" or "directly coupled to" another element or layer. When referred to, there are no intervening elements or layers present. Other terms used to describe relationships between elements are used in a similar fashion (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). ) should be interpreted. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The spatially relative terms "inside", "outside", "behind", "below", "low", "above", "high", etc., refer to an element or feature as illustrated. It is used here to facilitate the description describing its relationship to other elements or features. Spatially-relative terms can be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, when the device in the figures is turned over, elements described as "below" or "beneath" other elements or features are oriented "above" the other elements or features. Thus, the term "bottom" can encompass both an orientation of up and down. The device may be oriented in other directions (rotated 90 degrees or other orientations) and the spatially relative descriptors used herein interpreted accordingly. .

The vehicle drive system 1 is not limited to the configuration described above. For example, although the example provided with one motor generator 3 was shown, it is not limited to this. A plurality of motor generators may be provided. Although an example in which the power conversion device 4 includes the inverter 6 as the power conversion unit is shown, the present invention is not limited to this. For example, the configuration may include a plurality of inverters. At least one inverter and a converter may be provided. Only a converter may be provided.

A switching element is not limited to IGBT11. For example, a MOSFET may be employed. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. In the case of an n-channel MOSFET, the source electrode corresponds to the first main electrode and the drain electrode corresponds to the second main electrode. In the case of MOSFET, a parasitic diode (body diode) may be used as a freewheeling diode, or an external diode may be used.

Although an example in which the rear surfaces 50b and 60b of the wiring members 50 and 60 are exposed from the sealing body 30 has been shown, the present invention is not limited to this. At least one of the back surfaces 50 b and 60 b may be covered with the sealing body 30 . At least one of the back surfaces 50b and 60b may be covered with an insulating member (not shown) that is different from the sealing body 30 . Although an example in which the semiconductor device 20 includes the sealing body 30 is shown, the present invention is not limited to this. A configuration without the sealing body 30 may be employed.

Although an example in which the semiconductor device 20 includes only one semiconductor element 40 that forms one arm has been shown, the present invention is not limited to this. The semiconductor device 20 may include a plurality of semiconductor elements 40 forming one arm. That is, a plurality of semiconductor elements 40 may be connected in parallel to form one arm. In this case, the conductive spacers 70 are provided individually for the semiconductor elements 40 . Further, the semiconductor device 20 may include a plurality of semiconductor elements 40 forming the upper and lower arm circuits 9 for one phase. A plurality of semiconductor elements 40 forming the upper and lower arm circuits 9 of multiple phases may be provided.

The arrangement of the pads 44 and the shape of the conductive spacers 70 are not limited to the examples described above. The concave portion 71 may be opened in a portion of the side surface of the conductive spacer 70 excluding the portion facing the pad 44 in the direction in which the emitter electrode 42 (first main electrode) and the pad 44 are arranged.

DESCRIPTION OF SYMBOLS 1... Drive system, 2... DC power supply, 3... Motor generator, 4... Power converter, 5... Smoothing capacitor, 6... Inverter, 7... P line, 8... N line, 9... Upper and lower arm circuit, 9H... Upper arm , 9L...lower arm, 10...output line, 11...IGBT, 12...diode, 20...semiconductor device, 30...sealing resin body, 30a...first surface, 30b...back surface, 30c, 30d, 30e, 30f...side surface 40 Semiconductor element 41 Semiconductor substrate 41a One surface 41b Back surface 42 Emitter electrode 43 Collector electrode 44 Pad 50 Wiring member 50a Opposite surface 50b Back surface 60 Wiring member 60a... Opposing surface 60b... Back surface 70... Conductive spacer 70a, 70b... Opposing surface 70c, 70d, 70e, 70f... Side surface 71... Concave part 711... X-direction extending part 712... Y-direction extending part , 72... Partition wall, 80... External connection terminal, 81, 82... Main terminal, 83... Signal terminal, 90... Bonding wire, 91, 92, 93... Solder, 100... Connector, 110... Pedestal, 111... Spacer

Claims (9)

A semiconductor element having a first main electrode (42) and a signal pad (44) on one surface (41a) and a second main electrode (43) on a back surface (41b) opposite to the one surface in a plate thickness direction. (40) and
a first wiring member (50) electrically connected to the first main electrode;
a second wiring member (60) disposed so as to sandwich the semiconductor element between itself and the first wiring member in the plate thickness direction and electrically connected to the second main electrode;
a signal terminal (83) electrically connected to the pad via a bonding wire (100);
a conductive spacer (70) interposed between the semiconductor element and the first wiring member;
Solders (91, 92) respectively arranged between the second wiring member and the second main electrode, between the first main electrode and the conductive spacer, and between the conductive spacer and the first wiring member , 93) and
with
The conductive spacer is provided on a part of the surface (70b) facing the semiconductor element, and the portion of the side surface contiguous to the facing surface that faces the pad in the direction in which the first main electrode and the pad are arranged. A semiconductor device having a recessed portion (71) that opens to a portion other than the portion. The conductive spacer has a rectangular shape in a plan view from the plate thickness direction, and the side surface includes a first side surface (70d) including a portion facing the pad in the arrangement direction and the first side surface. having an opposite second side surface (70c), a third side surface (70e) continuous with the first side surface and the second side surface, and a fourth side surface (70f) opposite to the third side surface;
2. The semiconductor device according to claim 1, wherein said recess opens to at least one of said second side surface, said third side surface, and said fourth side surface. 3. The semiconductor device according to claim 2, wherein said recess is open to said second side surface. the recess is open to the second side surface, the third side surface, and the fourth side surface;
4. The semiconductor device according to claim 3, wherein an opening area on said second side surface is larger than each of an opening area on said third side surface and an opening area on said fourth side surface. 5. The semiconductor device according to claim 4, wherein said recess is continuously open over said second side, said third side and said fourth side. 6. The semiconductor device according to claim 4, wherein said recess is open to said third side surface and said fourth side surface at a position apart from said first side surface in said row direction. 3. The semiconductor device according to claim 2, wherein said recess opens to at least one of said third side surface and said fourth side surface. 8. The semiconductor device according to claim 2, wherein said recess is open to a portion of said first side surface excluding a portion facing said pad in said row direction. A semiconductor element having a first main electrode (42) and a signal pad (44) on one surface (41a) and a second main electrode (43) on a back surface (41b) opposite to the one surface in a plate thickness direction. providing (40), a first wiring member (50), a second wiring member (60), a signal terminal (83), and a conductive spacer (70);
Between the second wiring member and the second main electrode, between the first main electrode and the conductive spacer, and on the surface of the conductive spacer on the side opposite to the first main electrode, molten metal is formed between each of the conductive spacers. disposing solders (91, 92, 93) to form a connecting body (100) in which the second wiring member, the semiconductor element, and the conductive spacer are laminated in the plate thickness direction;
connecting the pad of the semiconductor element forming the connection body and the signal terminal with a bonding wire (90);
connecting the conductive spacer and the first wiring member by stacking and arranging the first wiring member and the connecting body after connecting the bonding wire and performing reflow;
with
provided on a part of the surface (70b) facing the semiconductor element, and opening in a portion of the side surface contiguous to the facing surface, excluding the portion facing the pad in the direction in which the first main electrode and the pad are arranged; A method of manufacturing a semiconductor device, comprising providing said conductive spacer with a recess (71) for forming a semiconductor device.

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