JP2016092346A - Power semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power semiconductor device which secures electrical connection with a surface of a power semiconductor device without using a joint material such as a solder, and has high reliability.SOLUTION: A power semiconductor device 100 includes: a heat dissipation substrate 1; a power semiconductor element provided on the heat dissipation substrate 1; a printed circuit board 5 arranged so as to face the power semiconductor element; and a conductive spring 4 for a main circuit that is a plate that has a plurality of projections, is a waveform and has elasticity, and of which both ends are joined to the printed circuit board and the plurality of projections are provided between the power semiconductor element and the printed circuit board 5 so as to be electrically connected to each of the power semiconductor element and the printed circuit board 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power semiconductor device on which a power semiconductor element used for an inverter or the like is mounted.

  A conventional power semiconductor device includes, for example, a circuit board, a power semiconductor element (semiconductor element for controlling current) mounted on the circuit board, a printed board provided above the circuit board, the semiconductor element and the printed circuit board. Some include a flexible terminal that electrically connects a part of the substrate. A flexible coil spring or leaf spring is used as the flexible terminal, and the lower end of the flexible terminal is bonded to the electrode surface of the semiconductor element using a bonding material such as solder. (For example, refer to Patent Document 1).

JP 2014-107378 A (paragraphs 0012 to 0019, FIG. 1)

  In such a power semiconductor device, the printed circuit board and the power semiconductor element are connected using a coil spring having flexibility, and are joined to the coil spring by a joining material such as solder. When a joint portion with a coil spring made of a joining material such as solder exists on the surface of a high-temperature power semiconductor element, when expansion and contraction due to heat are repeated, stress at the joint portion increases and peeling or the like occurs. Therefore, there was a problem with reliability.

  The present invention has been made to solve the above-described problems, and can ensure electrical connection with the surface of a power semiconductor element without using a bonding material such as solder, and has high reliability for power. An object is to provide a semiconductor device.

  A power semiconductor device according to the present invention includes a heat dissipation substrate, a power semiconductor element provided on the heat dissipation substrate, a printed circuit board disposed to face the power semiconductor element, and a waveform having a plurality of protrusions. It is a plate having elasticity of, provided between the power semiconductor element and the printed circuit board so that both ends are joined to the printed circuit board and the plurality of protrusions are electrically connected to the power semiconductor element and the printed circuit board, respectively. And a conductive main circuit spring.

  According to the power semiconductor device of the present invention, the main circuit spring is electrically connected to the surface of the power semiconductor element without using a bonding material such as solder when electrically connecting to the power semiconductor element. And a highly reliable power semiconductor device can be obtained.

It is principal part sectional drawing of the semiconductor device for electric power which concerns on Embodiment 1 of this invention. It is an external view of the spring for main circuits which concerns on Embodiment 1 of this invention. It is principal part sectional drawing of the semiconductor device for electric power which concerns on Embodiment 2 of this invention. It is principal part sectional drawing of the semiconductor device for electric power which concerns on Embodiment 3 of this invention. It is an external view of the spring for main circuits which concerns on Embodiment 3 of this invention. It is an external view of the spring for main circuits which concerns on Embodiment 4 of this invention. It is an external view of the modification of the spring for main circuits which concerns on Embodiment 4 of this invention. It is longitudinal direction sectional drawing of the spring for main circuits which concerns on Embodiment 5 of this invention. It is principal part sectional drawing of the power semiconductor device which concerns on Embodiment 6 of this invention. It is principal part sectional drawing of the surroundings of the printed circuit board which concerns on Embodiment 7 of this invention.

Embodiment 1 FIG.
A power semiconductor device according to a first embodiment of the present invention will be described with reference to FIGS. In the drawings, the same reference numerals are the same or equivalent, and this is common throughout the entire specification.

  FIG. 1 is a cross-sectional view of a main part of a power semiconductor device 100 according to Embodiment 1 of the present invention. As shown in FIG. 1, a power semiconductor device 100 according to Embodiment 1 of the present invention includes a heat dissipation board 1, a power semiconductor element, a printed board 5, a main circuit spring 4, a signal spring 3, and a housing 7. And a pressing lid 6.

  The heat dissipation substrate 1 is composed of a metal plate 1a, a first insulating layer 1b, and a wiring pattern 1c. As shown in FIG. 1, the metal plate 1a, the 1st insulating layer 1b, and the wiring pattern 1c are laminated | stacked and provided in order. The metal plate 1a and the wiring pattern 1c are made of a metal material such as copper or aluminum, and the thicknesses of the metal plate 1a and the wiring pattern 1c are appropriately determined depending on the current capacity of the power semiconductor element. Since the first insulating layer 1b needs to have both insulating properties and heat dissipation properties, a ceramic insulating material such as alumina, aluminum nitride, or boron nitride having good thermal conductivity, or an organic insulating material filled with an inorganic filler is used. It is done.

  The power semiconductor element is provided on the heat dissipation substrate 1 and is mounted on the wiring pattern 1c of the heat dissipation substrate 1 with a bonding material such as solder. Further, as power semiconductor elements, there are a self-extinguishing semiconductor element 2a, a reflux diode 2b, and the like. In the first embodiment of the present invention, as shown in FIG. 1, a self-extinguishing semiconductor element 2a and a reflux diode 2b are provided.

  The printed circuit board 5 is disposed so as to face the power semiconductor element provided on the heat dissipation board 1. On the surface of the second insulating layer 5c facing the power semiconductor element of the printed circuit board 5, a main circuit wiring electrode pattern 5a through which a main current flows and a control signal electrode pattern 5b for a control signal of the power semiconductor element Are formed by etching or the like. The metal material used for the main circuit wiring electrode pattern 5a and the control signal electrode pattern 5b is copper or aluminum, and copper is preferably used when a large current flows. The thicknesses of the main circuit wiring electrode pattern 5 a and the control signal electrode pattern 5 b are appropriately determined by the current capacity of the power semiconductor device 100. The second insulating layer 5c is generally made of a thermosetting resin such as an epoxy resin or a polyimide resin, and glass fibers are often used as a reinforcing member. On the other hand, the second insulating layer 5c may be an inorganic insulating layer such as ceramic.

  The main circuit spring 4 is a conductive plate having a wave-like elasticity having a plurality of protrusions 4a. The main circuit spring 4 is connected to the printed circuit board 5 at both ends 4b, and the plurality of protrusions 4a are electrically connected to the power semiconductor element and the printed circuit board 5, respectively. It is provided between. Further, the main circuit spring 4 is connected to a power semiconductor element in which a part of the plurality of protrusions 4a includes a self-extinguishing semiconductor element 2a and a return diode 2b.

  In the power semiconductor device 100 according to the first embodiment of the present invention, as shown in FIG. 1, the main circuit spring 4 has three protruding portions 4a protruding toward the heat dissipation substrate 1 and two protruding portions 4a protruding toward the printed circuit board 5. Have The three protrusions 4a protruding toward the heat radiating substrate 1 are electrically connected to the self-extinguishing semiconductor element 2a, the reflux diode 2b, and the wiring pattern 1c of the heat radiating substrate 1, respectively. Further, the two protruding portions 4 a protruding toward the printed circuit board 5 are electrically connected to the main circuit wiring electrode pattern 5 a of the printed circuit board 5. By using the main circuit spring 4, the self-quenching semiconductor element 2 a, the reflux diode 2 b, the wiring pattern 1 c of the heat dissipation board 1, and the main circuit wiring electrode pattern 5 a of the printed board 5 are individually wired to be electrically It is possible to make electrical connection in a lump instead of connecting them collectively. Accordingly, it is not necessary to individually wire the self-extinguishing type semiconductor element 2a, the return diode 2b, the wiring pattern 1c, and the main circuit wiring electrode pattern 5a, so that the assemblability is excellent. Both end portions 4b of the main circuit spring 4 are planar, and are bonded and fixed to the main circuit wiring electrode pattern 5a with a bonding material such as solder.

  Further, the main circuit spring 4 may have at least one of the plurality of projecting portions 4 a electrically connected to the heat dissipation substrate 1. In the power semiconductor device 100 according to the first embodiment of the present invention, among the plurality of protrusions 4a of the main circuit spring 4, one protrusion 4a protruding toward the heat dissipation board 1 is electrically connected to the heat dissipation board 1. Connected. Thereby, the main circuit spring 4 can obtain an electrical connection with the heat dissipation board 1 without using a bonding material such as solder, and high connection reliability can be obtained.

  FIG. 2 is an external view of the main circuit spring 4 according to Embodiment 1 of the present invention. As shown in FIG. 2, the main circuit spring 4 is a corrugated elastic plate and has a plurality of protrusions 4a. The plurality of protrusions 4a of the main circuit spring 4 may have different protrusions depending on the shape of the heat dissipation board including the power semiconductor element. The first embodiment of the present invention has three protrusions 4a protruding toward the heat dissipation board 1 and two protrusions 4a protruding toward the printed circuit board 5, but the three protrusions protruding toward the heat dissipation board 1 from FIG. The rightmost protruding portion 4a of the portion 4a protrudes toward the heat dissipation substrate 1 from the other two protruding portions 4a. This is because the power semiconductor element is not provided on the wiring pattern 1c at the position corresponding to the right protrusion 4a, so that the right protrusion 4a corresponds to the other protrusion by the thickness of the power semiconductor element. This is because it protrudes toward the heat dissipation substrate 1 from 4a.

  Here, the width of the main circuit spring 4 (the depth direction in FIG. 2) is a width that can be connected to the guard ring of the power semiconductor element such as the self-extinguishing semiconductor element 2a and the freewheeling diode 2b.

  The main circuit spring 4 is a corrugated plate, is sandwiched between the heat dissipation substrate 1 and the printed circuit board 5 and is easily deformed when pressure is applied. The self-extinguishing semiconductor element 2a, the return diode 2b, and the wiring Sufficient electrical connection reliability with the pattern 1c can be ensured. Further, since the main circuit spring 4 is easily deformed, sufficient connection reliability can be ensured, the stress applied to the both end portions 4b of the main circuit spring 4 is reduced, and the connection between the both end portions 4b joined by solder or the like. Reliability is improved.

  The signal spring 3 has one end electrically connected to the control signal electrode pattern 5b and the other end electrically connected to the power semiconductor element.

  The material of the main circuit spring 4 and the signal spring 3 is preferably a conductive metal having a spring property and a small electric resistance. For example, a copper alloy such as a Corson alloy is used, but is not limited thereto. . The thickness of the main circuit spring 4 is preferably 0.2 mm to 1.0 mm. If the thickness of the main circuit spring 4 is less than 0.2 mm, the spring property is good, but since the cross-sectional area of the main circuit spring 4 is small, there may be a problem of heat generation during conduction. On the other hand, if the thickness of the main circuit spring 4 exceeds 1.0 mm, the cross-sectional area of the main circuit spring 4 increases, so there is no problem with heat generation at the time of conduction, but the spring property is reduced. 5 or the contact area may be reduced when electrically connecting to the main circuit wiring electrode pattern 5a.

  The housing 7 includes the heat dissipation board 1 and the printed board 5 and has a screw fastening portion 7a on the outer periphery. The casing 7 is provided with an external terminal 7b, and a main circuit wiring electrode pattern 5a to which the main circuit spring 4 is electrically connected, and a control signal to which the signal spring 3 is electrically connected. The electrode pattern 5b is electrically connected to the external terminal 7b provided on the housing 7. The external terminal 7b electrically connects the power semiconductor device 100 and the external device. The casing 7 is preferably made of thermoplastic resin such as polyphenylene sulfide (PPS), polybutylene terephthalate (PBT) or polyethylene reinforced with glass fiber, but is not limited thereto.

  The pressing lid 6 is fitted to the housing 7 and pressed from the surface opposite to the surface connected to the main circuit spring 4 of the printed circuit board 5. Further, the pressing lid 6 has a protrusion 6 a that comes into contact with a surface opposite to the surface connected to the main circuit spring 4 of the printed circuit board 5. In the first embodiment of the present invention, the pressing lid 6 uniformly pressurizes the second insulating layer 5c of the printed circuit board 5 with the projections 6a, and the main circuit spring 4 and the signal circuit sandwiched between the printed circuit board 5 and the heat radiating board 1. The spring 3 is elastically deformed by being pressurized.

  As a result, the main circuit spring 4 is electrically connected to the self-quenching semiconductor element 2a, the return diode 2b, the wiring pattern 1c, and the main circuit wiring electrode pattern 5a. Similarly, the signal spring 3 electrically connects the self-extinguishing semiconductor element 2a and the control signal electrode pattern 5b while maintaining a constant load. Since the main circuit spring 4 and the signal spring 3 are pressed by the pressing lid 6 and elastically deformed, a highly reliable electrical connection can be obtained. Here, the protrusions 6 a provided on the pressing lid 6 are appropriately arranged at positions where the printed circuit board 5 is uniformly pressed.

  The material used for the pressing lid 6 is desirably a high-strength material having excellent rigidity in order to pressurize the printed circuit board 5 uniformly. For example, a thermoplastic resin such as polyphenylene sulfide (PPS) reinforced with glass fiber, polybutylene terephthalate (PBT), or polyethylene is preferably used, but is not limited thereto. When higher strength is required, a pressing lid 6 in which a reinforcing metal plate 1a is inserted into the thermoplastic resin may be used.

  In the first embodiment of the present invention, the pressing lid 6 is fitted to the housing 7 as shown in FIG. A groove 7c for fitting the pressing lid 6 is formed in the housing 7, and the casing 7 is fitted by press-fitting the pressing lid 6 into the groove 7c. The groove 7c has substantially the same size as the thickness of the pressing lid 6, but the size is appropriately adjusted so that the pressing lid 6 can be press-fitted. Therefore, the pressing lid 6 can be easily fitted into the groove 7c, and the pressing lid 6 can be fixed. When the pressing lid 6 is fitted into the groove 7c, the projection 6a of the pressing lid 6 pressurizes the second insulating layer 5c, so that the main circuit spring 4 and the signal spring 3 are compressed and elastically deformed.

  Next, a method for assembling power semiconductor device 100 in the first embodiment of the present invention will be described. The self-extinguishing type semiconductor element 2a and the freewheeling diode 2b are mounted on the heat dissipation board 1, and the printed circuit board 5 on which the main circuit spring 4 and the signal spring 3 are mounted in advance and the heat dissipation board 1 are positioned. Thereafter, the printed circuit board 5 and the external terminal 7 b are bonded with a bonding material such as solder, the printed circuit board 5 is pressurized with the pressing lid 6, and the pressing lid 6 is pressed into the housing 7 and fixed. Then, sealing resin is injected into a space surrounded by the casing 7, the pressing lid 6, and the heat dissipation substrate 1. Note that a hole for injecting the sealing resin is provided in the pressing lid 6 (not shown). As the sealing resin, a sealing resin having a low elastic modulus may be used in order to maintain the spring properties of the main circuit spring 4 and the signal spring 3. Although it is desirable to use silicone gel or the like as the sealing resin, it is not limited to this.

  In the first embodiment of the present invention, two self-quenching semiconductor elements 2a and freewheeling diodes 2b are provided on the heat dissipation substrate 1 as power semiconductor elements. A plurality of power semiconductor elements may be provided on the heat dissipation substrate 1, and the main circuit spring 4 may be configured such that at least one of the plurality of protrusions 4 a is electrically connected to each of the plurality of power semiconductor elements. The main circuit spring 4 is electrically connected to each of the plurality of power semiconductor elements with at least one of the plurality of protrusions 4a, so that the plurality of power semiconductor elements, the wiring pattern 1c of the heat dissipation board 1, and The main circuit wiring electrode patterns 5a of the printed circuit board 5 can be electrically connected all at once, so that the assemblability is excellent and high connection reliability can be obtained.

  On the other hand, even if there is only one power semiconductor element, at least one of the plurality of protrusions 4a of the main circuit spring 4 is electrically connected to the power semiconductor element. Since the electrical connection between the main circuit spring 4 and the heat dissipation substrate 1 can be obtained without using a bonding material such as solder, a high connection reliability can be obtained. Since the surface of the power semiconductor element is particularly high in temperature, electrical connection with the main circuit spring 4 can be obtained without using a bonding material such as solder.

  Conventionally, the electrical connection between the power semiconductor elements or the electrical connection between the power semiconductor elements and the wiring pattern 1c is shown in the wire bond connection method or the prior art document (Japanese Patent Laid-Open No. 2014-107378). There was a connection method. In the both connection methods, stress is generated due to a difference in elastic modulus and a difference in thermal expansion coefficient at a joint between a joining member such as solder and a power semiconductor, or between a joining member such as solder and the wiring pattern 1c. As a result, cracks or peeling occurred and mechanical reliability and thermal reliability became a problem.

  As described above, in power semiconductor device 100 in the first embodiment of the present invention, heat dissipating substrate 1, power semiconductor element provided on heat dissipating substrate 1, and the power semiconductor element are arranged to face each other. The printed circuit board 5 is a corrugated elastic plate having a plurality of protrusions 4a. Both ends 4b are joined to the printed circuit board 5, and the plurality of protrusions 4a are electrically connected to the power semiconductor element and the printed circuit board 5, respectively. And a conductive main circuit spring 4 provided between the power semiconductor element and the printed circuit board 5.

  According to such a configuration, when electrically connecting to the power semiconductor element, the heat dissipation board 1 or the printed circuit board 5, the main circuit spring 4 is connected to the surface of the power semiconductor element, the heat dissipation board without using a bonding material. 1 or the electrical connection with the printed circuit board 5 can be ensured, and the power semiconductor device 100 with high connection reliability can be obtained.

  The main circuit spring 4 is excellent in assembling because the power semiconductor element, the wiring pattern 1c of the heat radiating board 1, and the main circuit wiring electrode pattern 5a of the printed board 5 can be easily wired together. In addition, since the electrical connection is made by pressurizing with the pressing lid 6 without using a joining material such as solder when electrically connecting, stress is generated due to the difference in thermal expansion coefficient as in the case of using the joining material. Since no cracks or peeling occurs at the joint, the power semiconductor device 100 having excellent mechanical and thermal long-term reliability can be obtained.

  Further, a step is generated on the heat dissipation substrate 1 by the thickness of the power semiconductor element provided on the heat dissipation substrate 1, but the amount of protrusion of the protrusion 4a of the main circuit spring 4 to the heat dissipation substrate 1 side is adjusted. As a result, the power semiconductor element, the wiring pattern 1c, and the main circuit wiring electrode pattern 5a can be easily and collectively connected, and therefore, the assembly is excellent. Furthermore, since the main circuit spring 4 has a spring property, the connection pressure at each connection portion can be equalized by free deformation of the main circuit spring 4, and the connection reliability at each connection portion is improved.

  Here, in order to solder the power semiconductor element, it is necessary to apply a new plating layer such as Ni plating to the power semiconductor element, which increases the cost. On the other hand, since it is not necessary to solder the power semiconductor element in the present invention, an existing Al front metal power semiconductor element can be used, and an increase in cost can be suppressed.

  Further, the printed circuit board 5 is arranged so as to face the heat dissipation board 1 on which the power semiconductor element is mounted, and the respective conduction can be obtained through the main circuit spring 4. Further, the main circuit spring 4 can be easily fixed only by joining both ends of the main circuit spring 4 to the printed circuit board 5, and the number of joints can be reduced as compared with the case where a coil spring or the like is used. it can. Furthermore, since the three-dimensional arrangement can be achieved, the power semiconductor device 100 can be reduced in size. Since downsizing is possible, more power semiconductor elements and the like can be provided in the power semiconductor device 100, and the density can be increased.

Embodiment 2. FIG.
A power semiconductor device 200 according to Embodiment 2 of the present invention will be described with reference to FIG. In the power semiconductor device 200 according to the first embodiment, the case where the printed circuit board 5 has one layer has been described. In the second embodiment of the present invention, a modification example in which the printed board 15 has two layers will be described. The following description will focus on differences from the first embodiment, and description of the same or corresponding parts will be omitted.

  FIG. 3 is a cross-sectional view of a main part of a power semiconductor device 200 according to the second embodiment of the present invention. As shown in FIG. 3, the power semiconductor device 200 according to the second embodiment includes a printed circuit board 15 in which electrode patterns are stacked in two layers. The main circuit wiring electrode pattern 15a on the surface connected to the main circuit spring 4 and the control signal electrode pattern 15b on the first layer on the surface connected to the signal spring 3 are opposite to each other. On the surface, a second-layer main circuit wiring electrode pattern 15a and a second-layer control signal electrode pattern 15b are provided. The main circuit wiring through hole 15d is formed in the main circuit wiring electrode pattern 15a, and the control signal through hole 15e is formed in the control signal electrode pattern 15b. The signal spring 3 connected to the self-extinguishing semiconductor element 2a, which is a power semiconductor element, is mounted in the control signal through hole 15e.

  The through hole 15d for main circuit wiring is provided in the printed circuit board 15 to conduct the first layer main electrode wiring electrode pattern 15a and the second layer main circuit wiring electrode pattern 15a. The wiring of the first-layer main circuit wiring electrode pattern 15a can be routed to the second-layer main circuit wiring electrode pattern 15a through the through hole 15d.

  The control signal through-hole 15e is provided in the printed circuit board 15 to conduct the first-layer control signal electrode pattern 15b and the second-layer control signal electrode pattern 15b, and passes through the control signal through-hole 15e. The first-layer control signal electrode pattern 15b can be routed to the second-layer control signal electrode pattern 15b. Here, the control signal through holes 15 e are formed in the same number as the signal springs 3. The signal spring 3 is connected to a gate electrode and further an emitter electrode in the self-extinguishing semiconductor element 2a which is a power semiconductor element. In the second embodiment of the present invention, the signal spring 3 is inserted and mounted in the control signal through hole 15e by soldering or the like. The signal spring 3 is formed of a spring made from a wire. Since the signal spring 3 made of a wire retains its elasticity, it can be connected to the gate electrode and the emitter electrode of the self-extinguishing semiconductor element 2a, which is a power semiconductor element, in a small area. Become.

  The through hole for main circuit wiring 15d and the through hole for control signal 15e are appropriately designed according to the current capacity flowing through the through hole with respect to the through hole diameter, the number of through holes, and the plating thickness in the through hole.

  The printed circuit board 15 may be composed of two or more layers, and at least one layer may form a negative electrode pattern. When the negative electrode pattern is formed on the printed board 15, the electric field cancels out because it is parallel to the wiring pattern 1 c (positive electrode pattern) of the heat dissipation board 1, and the inductance generated from the wiring of the power semiconductor device 200 can be reduced. Furthermore, the printed circuit board 15 on which the negative electrode pattern is formed is disposed at a position facing the heat dissipation board 1 and has a three-dimensional wiring structure via the main circuit spring 4. Therefore, it is not necessary to wire widely on a plane, and the power semiconductor device 200 can be downsized.

  As described above, according to the power semiconductor device 200 according to the second embodiment of the present invention, the printed circuit board 15 is composed of two or more layers, and the electrode pattern for main circuit wiring is formed on the surface connected to the main circuit spring 4. 15a and a control signal electrode pattern 15b, the main circuit wiring electrode pattern 15a is connected to the main circuit spring 4, and the control signal electrode pattern 15b has a control signal through hole 15e. The signal spring 3 connected to the semiconductor element is mounted in the control signal through hole 15e. The printed circuit board 15 is composed of two or more layers, and is characterized in that a main circuit wiring through-hole 15d is formed in the main circuit wiring electrode pattern 15a. Furthermore, the printed circuit board 15 is composed of two or more layers, and at least one layer forms a negative electrode pattern.

  According to such a configuration, since the signal spring 3 can be electrically connected to the power semiconductor element with a small area while maintaining the spring property, the printed circuit board 15 while maintaining the connection reliability, Further, the power semiconductor device 200 can be downsized.

  In addition, the printed circuit board 15 is composed of two or more layers, and at least one layer forms a negative electrode pattern, whereby inductance can be reduced and higher functionality can be achieved.

Embodiment 3 FIG.
A power semiconductor device 300 according to Embodiment 3 of the present invention will be described with reference to FIGS. In the third embodiment of the present invention, a modification of the main circuit spring 24 will be described. The following description will focus on differences from the first embodiment, and description of the same or corresponding parts will be omitted as appropriate.

  FIG. 4 is a cross-sectional view of a main part of a power semiconductor device 300 according to the third embodiment of the present invention. FIG. 5 is an external view of the main circuit spring 4 according to Embodiment 3 of the present invention. As shown in FIG. 4, the two protrusions 24a of the main circuit spring 24 are connected to the self-extinguishing semiconductor element 2a and the return diode 2b, which are power semiconductor elements, respectively. As shown in FIG. 5, the main circuit spring 24 in the third embodiment of the present invention is longer than the main circuit spring 24 in the first embodiment shown in FIG. 2 (both ends of the main circuit spring 24 in FIG. 5). This is a main circuit spring 24 for a negative electrode that is short in a straight direction connecting the portions 24b and has a small number of protrusions 24a. Since the main circuit spring 24 has one protrusion 24a on the printed circuit board 5 side and two protrusions 24a on the heat dissipation board 1 side, the printed circuit board 5, the self-extinguishing semiconductor element 2a, and the freewheeling diode 2b are electrically connected to each other. Can be connected.

  According to such a configuration, the main circuit spring 24 is a plate having a corrugated elasticity that is shortened in the longitudinal direction. Therefore, the main circuit spring 24 is deformed with a smaller pressure and has a spring property. Sex can be obtained. Further, since both ends 24b at both ends in the longitudinal direction of the main circuit spring 24 have a small force applied by the elasticity of the spring, the stress on the both ends 24b at both ends is reduced, and the joining reliability of the joint is improved. .

Embodiment 4 FIG.
A power semiconductor device according to a fourth embodiment of the present invention will be described with reference to FIGS. In the fourth embodiment of the present invention, a modification of the main circuit spring 34 (main circuit spring 44) will be described. The following description will focus on differences from the first embodiment, and description of the same or corresponding parts will be omitted.

  FIG. 6 is an external view of a main circuit spring 34 according to Embodiment 4 of the present invention. FIG. 7 is an external view of a modified example of the main circuit spring 44 according to the fourth embodiment of the present invention. As shown in FIG. 6, the main circuit spring 34 in the fourth embodiment has a plurality of slits 34c in the longitudinal direction. The main circuit spring 34 shown in FIG. 6 is a corrugated elastic plate having three protrusions 34a on the heat dissipation board 1 side and two protrusions 34a on the printed circuit board 5 side. Each of the diode 2b, the wiring pattern 1c, and the printed board 5 is electrically joined. On the other hand, the main circuit spring 44 shown in FIG. 7 has a plurality of slits 44c in the longitudinal direction, has two protruding portions 44a on the heat dissipating substrate 1 side, and one protruding portion 44a on the printed circuit board 5 side. It is a board which has. The self-quenching semiconductor element 2a, the freewheeling diode 2b, and the printed circuit board 5 are electrically connected to each other. The slit 4c is provided in the longitudinal direction of the main circuit spring 44, and is not provided at both end portions 44b at both ends joined to the main circuit wiring electrode pattern 5a by solder or the like.

  As shown in FIG. 6, when the slit 34c is formed in the longitudinal direction of the main circuit spring 34, the corrugated plate of the main circuit spring 34 is divided into strips. Since the strip-shaped plate is easily deformed when a force is applied, the contact area between the protruding part 34a and the self-extinguishing semiconductor element 2a, the return diode 2b, the wiring pattern 1c, or the printed circuit board 5 increases. To do. The number of slits 34c is not particularly limited, but if the number of slits 34c is too large, the area of the plate that can be contacted decreases and sufficient current capacity may not be obtained, so care must be taken to ensure the contact area. There is. In FIG. 6, although it is the linear slit 34c, a shape is not restricted to this, The slit 34c, such as a zigzag bent line | wire, may be sufficient. The main circuit spring 34 shown in FIG. 7 has the same characteristics as the main circuit spring 34 shown in FIG.

  As described above, according to the power semiconductor device of the fourth embodiment of the present invention, the main circuit spring 34 (main circuit spring 44) has a plurality of slits 34c (slits 44c) in the longitudinal direction. It is said.

  According to such a configuration, the plurality of slits 34 c (slits 44 c) are provided in the longitudinal direction of the main circuit spring 4, so that the main circuit spring 34 (main circuit spring 44) is divided into strips, and the force is increased. Since it deforms easily when added, the contact area between the power semiconductor element, the wiring pattern 1c, or the printed circuit board 5, and the protrusion 4a increases. Therefore, even if unevenness is generated on the contact surface, it is deformed individually, so that a sufficient connection area can be secured. Therefore, the connection reliability is improved and a sufficient current capacity can be obtained.

Embodiment 5 FIG.
A power semiconductor device according to a fifth embodiment of the present invention will be described with reference to FIG. In the fifth embodiment of the present invention, a modification of the main circuit spring 54 will be described. The following description will focus on differences from the third embodiment, and description of the same or corresponding parts will be omitted.

  FIG. 8 is a longitudinal sectional view of the main circuit spring 54 according to the fifth embodiment of the present invention. The main circuit spring 54 has a protrusion 54d on at least a part of the plurality of protrusions 54a. As shown in FIG. 8, the main circuit spring 54 according to the fifth embodiment is provided with protrusions 54d on two protrusions 54a on the heat dissipation board 1 side. Protrusion 54d is provided at a location where the main circuit spring 54 and the self-extinguishing semiconductor element 2a and the return diode 2b, which are power semiconductor elements, are electrically connected to each other. The reliability of electrical connection with the surface of the semiconductor element can be improved. On the other hand, due to the shape of the protrusion 54d, the area where the main circuit spring 54 and the surface of the power semiconductor element are connected may be reduced. In this case, the current capacity may be limited. Arise. Accordingly, the shape of the protrusion 54d is partially planar to ensure a connection area with the surface of the power semiconductor element. However, the shape of the protrusion 54d is not limited to a planar shape, and may be any shape that can secure a connection area with the surface of the power semiconductor element or the like.

  The protrusion 54d of the main circuit spring 54 may be formed by machining, or may be formed by joining another member to the main circuit spring 54 by welding or the like. If the protrusion 54d is formed by machining, it can be formed at low cost. In addition, you may provide the some slit shown in Embodiment 4 in the spring 54 for main circuits of Embodiment 5 of this invention.

  Although the fifth embodiment of the present invention has been described with a focus on differences from the third embodiment, there is no problem if the main circuit spring 54 of the first embodiment is provided with the protrusion 54d.

  As described above, according to the power semiconductor device of the fifth embodiment of the present invention, the main circuit spring 54 is characterized in that the protrusion 54d is provided on at least a part of the plurality of protrusions 54a.

  According to such a configuration, by providing the protrusion 54d at a location where the main circuit spring 54 and the power semiconductor element, the wiring pattern 1c, or the main circuit wiring electrode pattern 5a are electrically connected, Connection reliability can be improved.

Embodiment 6 FIG.
A power semiconductor device 600 according to Embodiment 6 of the present invention will be described with reference to FIG. In the power semiconductor device 600 according to the second embodiment, the case where the press lid 6 is press-fitted into the housing 7 and fixed has been described. In the sixth embodiment of the present invention, a modified example in which the pressing lid 66 and the housing 77 are fixed by screwing will be described. The following description will focus on differences from the second embodiment, and description of the same or corresponding parts will be omitted.

  FIG. 9 is a cross-sectional view of a main part of a power semiconductor device 600 according to the sixth embodiment of the present invention. The power semiconductor device 600 includes a casing 7 that encloses the heat dissipation board 1 and the printed board 15, and the pressing lid 66 is screwed to the casing 7. As shown in FIG. 9, the power semiconductor device 600 according to the sixth embodiment of the present invention has a structure in which the pressing lid 6 is fitted to the housing 7 illustrated in the second embodiment, but not on the outer periphery of the housing 77. In the provided screw fastening portion 77a, the housing 77 and the pressing lid 66 are fixed. When the pressing lid 66 is fastened with a heat radiating device such as a radiating fin with a screw, the projection 66 a of the pressing lid 66 presses the printed circuit board 15, and a force can be applied to the main circuit spring 4 and the signal spring 3.

  Although the sixth embodiment of the present invention has been described mainly with respect to differences from the second embodiment, the power lid device 66 and the housing of the sixth embodiment of the present invention are added to the power semiconductor device 100 of the first embodiment. There is no problem applying the body 77.

  As described above, according to the power semiconductor device 600 according to the sixth embodiment of the present invention, the power semiconductor device 600 includes the housing 77 including the heat dissipation board 1 and the printed board 15, and the pressing lid 66 includes the housing. It is characterized by being screwed to the body 77.

  According to such a configuration, since the pressing lid 66 is fixed by screw tightening, there is no problem that the pressure applied from the pressing lid 66 to the printed circuit board 5 fluctuates due to vibration, heat history, or the like. As a result, the connection reliability of the signal spring 3 and the main circuit spring 4 can be improved.

Embodiment 7 FIG.
A power semiconductor device according to a seventh embodiment of the present invention will be described with reference to FIG. In the seventh embodiment of the present invention, the case where the electronic component 8 is mounted on the printed circuit board 65 will be described. The following description will focus on differences from the first embodiment, and description of the same or corresponding parts will be omitted.

  FIG. 10 is a cross-sectional view of a main part around the printed circuit board 65 according to Embodiment 7 of the present invention. The printed circuit board 65 is composed of two or more layers, and the electronic component 8 is mounted on the outermost layer surface opposite to the surface connected to the main circuit spring 4. As shown in FIG. 10, in the seventh embodiment of the present invention, the printed circuit board 65 in the power semiconductor device is constituted by three layers of electrode patterns. The second insulating layer 65c is composed of two parallel insulating layers, and electrode patterns are provided on both surfaces of either insulating layer.

  The first second insulating layer 65c has a first layer main circuit wiring electrode pattern 65a on the surface connected to the main circuit spring 4 and a first layer control signal use on the surface connected to the signal spring 3. And an electrode pattern 65b. Further, the second insulating layer 65c of the first layer is a main circuit wiring electrode of the second layer on the opposite side of the surface on which the main circuit wiring electrode pattern 65a and the control signal electrode pattern 65b of the first layer are formed. Each has a pattern 65a and a control signal electrode pattern 65b. Further, the second insulating layer 65c of the second layer is for the main circuit wiring of the third layer on the opposite side of the surface on which the electrode pattern 65a for the second layer and the electrode pattern for control signal 65b are respectively formed. Each has an electrode pattern 65a and a control signal electrode pattern 65b. The main circuit wiring through hole 65d is formed in the main circuit wiring electrode pattern 65a, and the control signal through hole 65e is formed in the control signal electrode pattern 65b.

  The signal spring 3 is mounted in the control signal through hole 65e. Furthermore, the outermost layer surface in the direction opposite to the surface connected to the main circuit spring 4 (first-layer main circuit wiring electrode pattern 65a) is a drive circuit on which electronic components 8 such as resistors are mounted.

  As described above, according to the power semiconductor device according to the seventh embodiment of the present invention, the printed circuit board 65 is composed of two or more layers, and on the outermost layer surface in the direction opposite to the surface connected to the main circuit spring 4, The electronic component 8 is mounted.

  According to such a configuration, since the power semiconductor device has a built-in drive circuit on which the electronic component 8 such as a resistor is mounted, the power semiconductor is compared with the case where the drive circuit is provided outside the power semiconductor device. The wiring distance to the element is shortened and the response is improved. Therefore, a power semiconductor device that is highly reliable and can be miniaturized can be obtained.

  Note that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be modified or omitted as appropriate.

DESCRIPTION OF SYMBOLS 1 Heat dissipation board, 2a Self-extinguishing type semiconductor element, 2b Return diode, 3 Signal spring, 4 Main circuit spring, 4a protrusion part, 4b Both ends, 4c Slit, 4d Protrusion, 5 Printed board, 5a Main circuit wiring Electrode pattern, 5b control signal electrode pattern, 5d main circuit wiring through hole, 5e control signal through hole, 6 pressing lid, 6a protrusion, 7 housing, 8 electronic components

Claims (14)

A heat dissipation substrate;
A power semiconductor element provided on the heat dissipation substrate;
A printed circuit board disposed to face the power semiconductor element;
It is a corrugated plate having a plurality of protrusions, both ends are joined to the printed circuit board, and the plurality of protrusions are electrically connected to the power semiconductor element and the printed circuit board, respectively. A conductive main circuit spring provided between the power semiconductor element and the printed circuit board;
A power semiconductor device comprising: A plurality of power semiconductor elements,
The power semiconductor device according to claim 1, wherein at least one of the plurality of protrusions is electrically connected to each of the plurality of power semiconductor elements in the main circuit spring. The printed circuit board is composed of two or more layers, and has a main circuit wiring electrode pattern and a control signal electrode pattern on a surface connected to the main circuit spring,
The main circuit wiring electrode pattern is connected to the main circuit spring,
3. The power signal according to claim 1, wherein the control signal electrode pattern has a control signal through hole, and a signal spring connected to the power semiconductor element is mounted in the signal through hole. Semiconductor device. The power semiconductor element is composed of a self-extinguishing semiconductor element and a reflux diode,
4. The main circuit spring is configured such that a part of the plurality of protrusions is connected to the self-extinguishing semiconductor element and the reflux diode, respectively. 5. Power semiconductor devices. The power semiconductor device according to claim 1, wherein the main circuit spring has a plurality of slits in a longitudinal direction. The power semiconductor device according to claim 1, wherein the main circuit spring has a protrusion on at least a part of the plurality of protrusions. The power semiconductor device according to claim 1, further comprising: a pressing lid that presses from a surface opposite to a surface connected to the main circuit spring of the printed circuit board. The power semiconductor device according to claim 7, wherein the pressing lid has a protrusion that contacts the opposite surface. A housing enclosing the heat dissipation board and the printed board,
The power semiconductor device according to claim 7, wherein the pressing lid is fitted to the housing. A housing enclosing the heat dissipation board and the printed board,
The power semiconductor device according to claim 7, wherein the pressing lid is screwed to the housing. The power semiconductor device according to claim 1, wherein at least one of the plurality of projecting portions is electrically connected to the heat dissipation substrate in the main circuit spring. The power semiconductor device according to claim 3, wherein the printed circuit board includes two or more layers, and a through hole for main circuit wiring is formed in the electrode pattern for main circuit wiring. The power semiconductor device according to any one of claims 1 to 12, wherein the printed board includes two or more layers, and at least one layer forms a negative electrode pattern. The electric power according to any one of claims 1 to 13, wherein the printed circuit board includes two or more layers, and an electronic component is mounted on an outermost layer surface in a direction opposite to a surface connected to the main circuit spring. Semiconductor device.

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