JP2022029886A - Semiconductor device, manufacturing method thereof, and power conversion device - Google Patents

Abstract

To provide a semiconductor device capable of reducing the thermal resistance between a heat radiating member and a wiring board without a metal layer of the wiring board being limited to Al.SOLUTION: A substrate device 100 includes an Al-made heat dissipation member 1, a wiring board 2 to which a first metal layer 2b made of Cu is bonded on the heat dissipation member 1 via a bonding member 10, and a semiconductor element 4 bonded via a solder 3 on a second metal layer 2c of the wiring board 2. The bonding member 10 includes a first bonding layer 10a made of Cu and a second bonding layer 10b made of Al provided on the first bonding layer 10a. A substrate portion 1a of the heat dissipation member 1 and the first bonding layer 10a of the bonding member 10 are solid-phase diffusion bonded, and the first metal layer 2b of the wiring board 2 and the second bonding layer 10b of the bonding member 10 are solid-phase diffusion bonded.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to semiconductor devices, methods for manufacturing semiconductor devices, and power conversion devices.

In a conventional semiconductor device, a wiring board on which a semiconductor element is mounted and a heat-dissipating member joined to the wiring board are provided, and Al (aluminum) is widely used as a material for the heat-dissipating member. Soldering is generally used as a method for joining the heat radiating member and the metal layer of the wiring board, but the thermal expansion coefficient between the heat radiating member made of Al and the wiring board having an insulating layer such as a ceramic base material is used. Since there is a large difference, it is necessary to make the joint thicker to reduce the thermal strain in order to reduce the thermal stress of the joint. However, since solder has a low thermal conductivity, there is a problem that the thermal resistance between the heat radiating member and the wiring board increases by thickening the joint portion. Therefore, there is a technique of solid-phase diffusion bonding between an Al-made heat dissipation member and an Al-made metal layer by a Cu layer without using solder (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-60215

However, in the semiconductor device described in Patent Document 1, the metal layers provided on both sides of the insulating layer in the wiring substrate are limited to those made of Al in order to perform solid phase diffusion bonding via the Cu layer. In this case, in order to join the semiconductor element with solder, there is a problem that surface treatment such as plating the surface of the metal layer is required.

The present disclosure has been made to solve the above-mentioned problems, and the metal layer of the wiring board is not limited to that of Al, and the thermal resistance between the heat dissipation member and the wiring board can be reduced. The purpose is to obtain the device.

The semiconductor device according to the present disclosure has a heat radiating member having a flat plate-shaped substrate portion, a first bonding layer provided on the substrate portion of the heat radiating member, and a second bonding layer provided on the first bonding layer. A wiring board having a joining member, a first metal layer provided on the second joining layer of the joining member, an insulating layer provided on the first metal layer, and a second metal layer provided on the insulating layer. The semiconductor element provided on the second metal layer of the wiring board is provided, and the substrate portion of the heat dissipation member and the second joining layer of the joining member are formed of Al or Al alloy, and the first metal of the wiring board is provided. The surface layer on the side of at least the second bonding layer of the layer and the first bonding layer of the bonding member are characterized by being formed of Cu or Cu alloy, or Ni or Ni alloy.

In the method for manufacturing a semiconductor device according to the present disclosure, a substrate portion of a heat radiating member and a first bonding layer of a bonding member having a first bonding layer and a second bonding layer provided on the first bonding layer are bonded. A wiring having a first step, a second joining layer of a joining member, an insulating layer, a first metal layer provided on one surface of the insulating layer, and a second metal layer provided on the other surface of the insulating layer. A second step of joining the first metal layer of the substrate and a third step of joining the second metal layer of the wiring board and the semiconductor element are included, and the substrate portion of the heat dissipation member and the joining are included. The second bonding layer of the member is formed of Al or Al alloy, and the surface layer on the opposite side of the first metal layer of the wiring board at least on the insulating layer side and the first bonding layer of the bonding member are Cu or Cu alloy, or , Ni or Ni alloy.

The semiconductor device according to the present disclosure has an effect that the thermal resistance can be reduced without limiting the metal layer of the wiring board to be made of Al.

The method for manufacturing a semiconductor device according to the present disclosure has an effect that a semiconductor device having reduced thermal resistance can be obtained without the metal layer of the wiring board being limited to Al.

It is sectional drawing which shows the semiconductor device of Embodiment 1. FIG. It is a perspective view which shows the structure of a part of the semiconductor device of Embodiment 1. FIG. It is sectional drawing for demonstrating the process of the first half of the manufacturing method of the semiconductor device of Embodiment 1. FIG. It is sectional drawing for demonstrating the latter half process of the manufacturing method of the semiconductor device of Embodiment 1. FIG. It is sectional drawing which shows the semiconductor device of Embodiment 2. It is a perspective view which shows the structure of a part of the semiconductor device of Embodiment 2. It is a top view for demonstrating the divided structure of the joining member provided in the semiconductor device of Embodiment 2. FIG. It is sectional drawing for demonstrating the process of the first half of the manufacturing method of the semiconductor device of Embodiment 2. It is sectional drawing for demonstrating the latter half process of the manufacturing method of the semiconductor device of Embodiment 2. It is sectional drawing which shows the partial structure which concerns on 1st example of the semiconductor device of Embodiment 3. It is sectional drawing which shows the partial structure which concerns on the 2nd example of the semiconductor device of Embodiment 3. It is sectional drawing which shows the semiconductor device of Embodiment 4. It is sectional drawing for demonstrating the manufacturing method of the semiconductor device of Embodiment 4. It is sectional drawing which shows the semiconductor device of Embodiment 5. It is sectional drawing for demonstrating the process of the first half of the manufacturing method of the semiconductor device of Embodiment 5. It is sectional drawing for demonstrating the latter half process of the manufacturing method of the semiconductor device of Embodiment 5. It is a block diagram for demonstrating the power conversion apparatus of Embodiment 6.

Hereinafter, embodiments will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated. Further, the numerical values such as dimensions, temperature, and time described below are examples, and may be other numerical values. Further, in the following description, terms that mean a specific direction of "up" or "down" may be used, but these terms are used for convenience and are used in practice. It has nothing to do with the direction.

Further, in the present disclosure, the term "upper" does not prevent the presence of inclusions between the components. For example, when the description is described as "B provided on A", it includes those in which another component C is provided or not provided between A and B.

Further, in the present disclosure, each member may be described as being made of Al (aluminum), Cu (copper) or Ni (nickel), but Al is an Al alloy containing Al or Al as a main component. What is formed is Cu, which is formed of Cu or a Cu alloy containing Cu as a main component, and Ni, which is formed of Ni or a Ni alloy containing Ni as a main component. It shall mean each.

Embodiment 1.
The semiconductor device of the first embodiment and the manufacturing method of the semiconductor device will be described with reference to FIGS. 1 to 4.

First, the semiconductor device of the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing the semiconductor device 100 of the present embodiment, and FIG. 2 is a perspective view showing a partial configuration of the semiconductor device 100.

As shown in FIG. 1, the semiconductor device 100 is a wiring substrate in which a first metal layer 2b is joined to a heat radiating member 1 having a substrate portion 1a and pin fins 1b, and a first metal layer 2b on the substrate portion 1a of the heat radiating member 1 via a joining member 10. 2. Attached to the case 6 and the case 6 bonded to the outer peripheral side surface of the semiconductor element 4, the joining member 10, and the wiring board 2 bonded via the solder 3 on the second metal layer 2c of the wiring board 2. Main terminal 7a and signal terminal 7b, wire 8a that electrically connects the main terminal 7a and the semiconductor element 4, wire 8b that electrically connects the signal terminal 7b and the semiconductor element 4, and the heat dissipation member 1 and the case. The sealing material 9 to be filled in the area surrounded by 6 is provided.

Here, the bonding member 10 has a first bonding layer 10a made of Cu and a second bonding layer 10b made of Al laminated on the first bonding layer 10a, and is integrally formed. Further, the heat radiating member 1 is made of Al, and the substrate portion 1a of the heat radiating member 1 and the first joining layer 10a of the joining member 10 are joined. Further, the first metal layer 2b and the second metal layer 2c of the wiring board 2 are made of Cu, and the first metal layer 2b of the wiring board 2 and the second metal layer 10b of the joining member 10 are joined to each other. In other words, the first joining layer 10a of the joining member 10 is provided on the substrate portion 1a of the heat radiating member 1, and the first metal layer of the wiring board 2 is provided on the second joining layer 10b of the joining member 10. 2b is provided.

As shown in FIGS. 1 and 2, the heat radiating member 1 has a substrate portion 1a and a plurality of pin fins 1b, and is a prismatic column having a side surface of 2 mm width and a height of 8 mm on the lower surface of the flat plate-shaped substrate portion 1a. 256 pin fins 1b (16 × 16) are provided. Further, the heat radiating member 1 is made of Al, and the substrate portion 1a and the pin fin 1b are integrally formed by forging, for example. A first joining layer 10a of the joining member 10 is provided on the upper surface of the substrate portion 1a of the heat radiating member 1, and the substrate portion 1a made of Al and the first joining layer 10a made of Cu are joined.

The heat radiating member 1 is not particularly limited as long as it is formed of Al or an Al alloy containing Al as a main component, but if it is formed of an Al alloy such as JIS A6063 or JIS A6061, the thermal conductivity is almost impaired. It is desirable because it is possible to increase the strength without increasing the strength. Further, the heat radiating member may be one having at least a flat plate-shaped substrate portion, and may be provided with fins other than pin fins, or a heat radiating member composed of only a flat plate-shaped substrate portion or the like. It may not be prepared.

As shown in FIG. 1, the wiring substrate 2 is a Cu-made first metal layer provided on the lower surface of one surface of an AlN (aluminum nitride) ceramic base material 2a as an insulating layer and a ceramic base material 2a. It has a second metal layer 2c made of Cu provided on the upper surface of the 2b and the other surface of the ceramic base material 2a. That is, the ceramic base material 2a as an insulating layer is provided on the first metal layer 2b, and the second metal layer 2c is provided on the ceramic base material 2a. In the wiring board 2, the external dimensions of the ceramic base material 2a are, for example, 65 mm × 65 mm × thickness 0.64 mm, and the external dimensions of the first metal layer 2b and the second metal layer 2c are, for example, 61 mm × 61 mm × thickness 0. It is 4 mm. The first metal layer 2b of the wiring board 2 is provided on the second joining layer 10b of the joining member 10, and the second joining layer 10b made of Al and the first metal layer 2b made of Cu are joined. Further, as shown in FIG. 2, the second metal layer 2c is composed of a conductor pattern divided into six pieces.

The wiring substrate 2 of the present embodiment has a ceramic base material 2a made of AlN as an insulating layer, but the present invention is not limited to this, and a ceramic base material made of Si _{3N 4 (} silicon nitride) is used. Therefore, the bending strength can be increased to suppress cracking. Further, by using a ceramic base material made of Al ₂ O ₃ (alumina), the coefficient of thermal expansion can be increased, the thermal stress can be reduced, and the reliability can be improved.

As shown in FIG. 1, a plurality of semiconductor elements 4 are joined and provided on the second metal layer 2c of the wiring board 2 by soldering 3. The material of the solder 3 is, for example, a solder manufactured by Senju Metal Co., Ltd. (model number: M705, before joining) having a composition ratio of 96.5 wt% Sn-3.0 wt% Ag-0.5 wt% Cu and a melting point of 219 ° C. External dimensions: 15 mm × 12 mm × thickness 0.1 mm) can be used.

Here, the semiconductor element 4 provided on each divided conductor pattern of the second metal layer 2c has, for example, a diode made of Si (silicon) having an external dimension of 15 mm × 12 mm × 0.2 mm, and for example, an external dimension. It is an IGBT (Insulated Gate Bipolar Transistor) made of Si having a size of 15 mm × 12 mm × 0.2 mm. That is, two semiconductor elements 4 are mounted on each of the six conductor patterns constituting the second metal layer 2c, and twelve semiconductor elements 4 are provided in the entire semiconductor device 100.

In this embodiment, a case where a Si diode and an IGBT are provided as the semiconductor element 4 will be described, but the present invention is not limited to this, and is not limited to this, for example, an IC (Integrated Circuit) or a MOSFET (Metal-Oxide-Semiconductor Field). -A semiconductor element such as an Effect Transistor) may be provided. Further, the semiconductor element is not limited to Si, and may be made of, for example, SiC (silicon carbide) or GaN (gallium nitride).

Further, in the present embodiment, the semiconductor device 100 having a 6in1 module configuration in which 6 pairs of IGBTs and diodes are provided will be described, but the present invention is not limited to this, and discrete components and semiconductor devices in which one semiconductor element is provided are described. It may be a 1in1 module in which one pair is provided, a 2in1 module in which two pairs of semiconductor elements are provided, or the like.

The composition ratio of the solder 3 is not limited to 96.5 wt% Sn-3.0 wt% Ag-0.5 wt% Cu, for example, 98.5 wt% Sn-1 wt% Ag-0.5 wt% Cu or 96 wt. A solder material having a composition ratio such as% Sn-3 wt% Sb-1 wt% Ag may be used. Further, instead of the solder 3, a highly heat-resistant Cu-Sn paste obtained by dispersing copper powder and coagulating it at an isothermal temperature, or a nano-silver paste bonded by low-temperature firing of nano-silver particles is used. May be good.

The case 6 is formed of PPS (Polyphenylene Sulfide) resin and has a frame-like shape having a plurality of surfaces surrounding the outer periphery of the joining member 10 and the wiring board 2. Silicone is formed on the heat radiating member 1, the joining member 10 and the wiring board 2. It is adhered by the adhesive 5 made of the product. The external dimensions of the case 6 are, for example, 85 mm × 85 mm × height 15 mm.

The case 6 is not limited to the one made of PPS resin, and may be formed by using, for example, an LCP (Liquid Crystal Polymer / liquid crystal polymer) resin or the like. Further, the case 6 may have a structure that is adhered to at least one of the heat radiating member 1, the joining member 10 and the wiring board 2 by the adhesive 5, and does not leak when the material of the sealing material 9 is injected. ..

Further, a main terminal 7a and a signal terminal 7b are attached to the case 6 as external terminals by insert molding. The main terminal 7a and the signal terminal 7b are made of Cu and Ni-plated, and their respective thicknesses are, for example, 1.0 mm.

The wires 8a and 8b are made of Al. Of these, the wire 8a that electrically connects the semiconductor element 4 and the main terminal 7a forms a main power circuit, and has a diameter of, for example, 0.4 mm. On the other hand, the wire 8b connecting the semiconductor element 4 and the signal terminal 7b forms a signal circuit, and has a diameter of, for example, 0.15 mm. The wires 8a and 8b are not limited to those made of Al. For example, a ribbon bond made of Al or a wire made of Cu may be used for the wire 8a joined to the main terminal 7a, or a wire connected to the signal terminal 7b. Ag (silver) wire or Au (gold) wire may be used for 8b.

Here, FIG. 1 schematically shows the electrical connection between each semiconductor element and the wire, and actually shows the wire existing on the back side of the paper in FIG. 1 as well. The same applies to the illustration of the wire in the other cross-sectional views described below.

The sealing material 9 is filled in a region surrounded by the heat radiating member 1 and the case 6, and insulates and seals the semiconductor element 4 and the wires 8a and 8b. The encapsulant 9 is formed of, for example, a thermosetting silicone gel. The material of the sealing material 9 is not limited to the silicone gel, and may be formed by using, for example, an epoxy resin containing a silica filler or the like.

The joining member 10 is provided between the heat radiating member 1 and the wiring board 2, and is a member for joining the heat radiating member 1 and the wiring board 2. As shown in FIGS. 1 and 2, the joining member 10 has a first joining layer 10a made of Cu and a second joining layer 10b made of Al provided on the first joining layer 10a, and is subjected to cold pressure welding. It is a clad material formed integrally. The first bonding layer 10a made of Cu has a thickness of, for example, 0.5 mm, and the second bonding layer 10b made of Al has a thickness of, for example, 1.5 mm. That is, the joining member 10 is formed so that the thickness of the second joining layer 10b is larger than the thickness of the first joining layer 10a. By doing so, it is possible to manufacture the joining member 10 as a whole at low cost, and to secure a thickness capable of reducing thermal stress.

The first bonding layer 10a of the bonding member 10 is provided on the substrate portion 1a of the heat radiating member 1, and the first bonding layer 10a made of Cu and the substrate portion 1a made of Al are bonded. Further, a first metal layer 2b of the wiring board 2 is provided on the second bonding layer 10b, and the second bonding layer 10b made of Al and the first metal layer 2b made of Cu are bonded. In this way, by using the joining member 10 having the first joining layer 10a and the second joining layer 10b, the substrate portion 1a made of Al and the first metal layer 2b made of Cu are connected to each other via the joining member 10. Can be joined together.

In the present embodiment, the case where the second bonding layer 10b of the bonding member 10 is formed thicker than the first bonding layer 10a has been described, but the present invention is not limited to this, and the first bonding layer and the second bonding layer are not limited to this. The bonding layer may be formed to have the same thickness, or the first bonding layer may be formed thicker than the second bonding layer. For example, when the demand for heat dissipation is high, the heat dissipation of the entire joining member can be improved by thickening the first bonding layer made of Cu.

Further, the second bonding layer 10b of the bonding member 10 is not particularly limited as long as it is formed of Al or an Al alloy, but for example, the JIS A1000 series is softer than JIS A6063 and the like, and the first metal layer 2b of the wiring board 2 is used. It is desirable because even if the surface of the aluminum is uneven, it can be adhered and the bondability is improved. The first bonding layer 10a of the bonding member 10 is not particularly limited as long as it is formed of Cu or a Cu alloy, but it is desirable to use a material having a high thermal conductivity such as JIS C1020 or JIS C1100.

Further, in the present embodiment, the case where the joining member 10 is a clad material integrally formed by cold pressure welding will be described, but the joining member has the first joining layer and the second joining layer having the above-described configuration. Any member may be used, and the joining method is not limited to cold pressure welding. Further, when bonded by cold pressure welding, the amount of the intermetallic compound layer formed between the first bonding layer and the second bonding layer is very small, but the subsequent heating produces a large amount of intermetallic compounds. Therefore, there is no problem with the amount of intermetallic compound produced and the thickness of the intermetallic compound layer.

Here, the heat radiating member 1 is made of Al, and the substrate portion 1a of the heat radiating member 1 and the first bonding layer 10a of the bonding member 10 are bonded by solid phase diffusion bonding. Further, the first metal layer 2b and the second metal layer 2c of the wiring board 2 are made of Cu, and the first metal layer 2b of the wiring board 2 and the second bonding layer 10b of the bonding member 10 are bonded by solid phase diffusion bonding. Has been done. That is, the bonding between the substrate portion 1a of the heat radiating member 1 and the first bonding layer 10a of the bonding member 10 and the bonding between the first metal layer 2b of the wiring board 2 and the second bonding layer 10b of the bonding member 10 are performed, respectively. This is a solid phase diffusion bond between the Al layer and the Cu layer. Therefore, although not shown, an intermetallic compound layer is actually formed between the layers joined by solid phase diffusion bonding. That is, between the substrate portion 1a of the heat radiating member 1 and the first joining layer 10a of the joining member 10, and between the first metal layer 2b of the wiring board 2 and the second joining layer 10b of the joining member 10. An intermetallic compound layer is formed in each case. Since each layer may have a density gradient, the boundary may be unclear.

Next, the method of manufacturing the semiconductor device according to the first embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a cross-sectional view for explaining the first half process of the manufacturing method of the semiconductor device 100 of the present embodiment, and FIG. 4 is a cross-sectional view for explaining the second half step of the manufacturing method of the semiconductor device 100. ..

First, as shown in FIG. 3A, the bonding member 10 is placed between the heat radiating member 1 and the wiring board 2, and the substrate portion 1a of the heat radiating member 1 and the first bonding layer 10a of the bonding member 10 face each other. , The first metal layer 2b of the wiring board 2 and the second bonding layer 10b of the bonding member 10 are arranged so as to face each other. Then, the substrate portion 1a and the first bonding layer 10a are brought into contact with each other, and the surface layer of the first metal layer 2b and the second bonding layer 10b are brought into contact with each other. Heat for 3 minutes. In this way, the substrate portion 1a made of Al and the first bonding layer 10a made of Cu are solid-phase diffusion bonded, and at the same time, the first metal layer 2b made of Cu and the second bonding layer 10b made of Al are solidified. Phase diffusion bonding. That is, here, solid phase diffusion bonding is performed by heating while pressurizing.

In this embodiment, the joining condition of heating at 400 ° C. for 3 minutes while applying a pressure of 2 MPa will be described, but the present invention is not limited to this, and for example, the pressure is set to 1 MPa in order to suppress the deformation of the pin fin 1b. The joining conditions may be appropriately changed, such as joining by lowering the temperature, raising the temperature to 500 ° C., and heating for 1 minute. However, when bonding is performed using a bonding member 10 having a first bonding layer 10a made of Cu and a second bonding layer 10b made of Al, when the heating temperature exceeds 540 ° C., a liquid phase is generated by the eutectic reaction and voids are formed. The heating temperature is preferably 540 ° C. or lower because there is a concern that it is likely to occur.

Further, in order to suppress the deformation of the pin fin 1b in the above-mentioned joining step, the pin fin may not be arranged in the central portion of the substrate portion, and the central portion may be sandwiched between jigs to apply pressure, or the substrate portion may be applied. A thick pin fin may be provided in the central portion of the above, and the thick pin fin may be sandwiched between jigs to apply pressure. Further, it is also possible to suppress the deformation of the pin fin by forming a recess corresponding to the pin fin in the jig for applying the pressure so that the pressure is not directly applied to the pin fin.

The solid-phase diffusion bonding between the substrate portion 1a and the first bonding layer 10a and the solid-phase diffusion bonding between the first metal layer 2b and the second bonding layer 10b are performed simultaneously as described above to improve the manufacturing efficiency. Although it can be improved, it is not limited to this, and for example, when it is preferable to join under different joining conditions, it may be performed separately.

In this way, after the heat dissipation member 1 and the wiring board 2 are joined via the joining member 10 as shown in FIG. 3B, the semiconductor element 4 is attached to the conductor layer of the wiring board 2 by using the solder 3. It is joined on the second metal layer 2c. At this time, solder joining is performed using, for example, a reflow furnace. In this way, as shown in FIG. 3C, the semiconductor element 4 is joined and provided on the wiring board 2.

Next, as shown in FIG. 4A, the case 6 in which the main terminal 7a and the signal terminal 7b are insert-molded is subjected to the heat dissipation member 1, the wiring board 2, and the joining member 10 by using the silicone adhesive 5. Adhere to. At this time, for example, it is heated at 140 ° C. for 10 minutes. Here, the silicone gel injected into the case 6 described later may be adhered so as not to leak out.

After that, as shown in FIG. 4B, the main terminal 7a and the semiconductor element 4 are wired by a wire 8a using a wire bonder to form a main power circuit. Further, the signal terminal 7b and the semiconductor element 4 are wired by a wire 8b using a wire bonder to form a signal circuit.

Finally, as shown in FIG. 4C, the silicone gel is injected into the inside of the case 6, heated at 100 ° C. for 1.5 hours, and further heated at 140 ° C. for 1.5 hours to cure the encapsulant. Insulation sealing is performed as No. 9, and the semiconductor device 100 is completed.

The effect of the semiconductor device 100 and the manufacturing method of the semiconductor device 100 configured as described above will be described.

In semiconductor devices, Al, which has excellent heat dissipation and is lighter than Cu, is widely used as a material for heat dissipation members. Soldering is generally used as a method for joining the heat radiating member and the wiring board, but the Sn-based solder has a thermal conductivity of about 50 W / m · K, and the thermal conductivity of Al constituting the heat radiating member is about 50 W / m · K. It is low compared to (about 200 W / m · K) and the thermal conductivity of AlN (about 120 to 180 W / m · K) constituting the ceramic base material of the wiring substrate. Further, while the coefficient of thermal expansion of Al is 23 ppm / K, the coefficient of thermal expansion of AlN is about 5 to 7 ppm / K, and it can be seen that there is a large difference between the coefficients of thermal expansion of the two. From the above, in order to reduce the thermal stress of the joint and ensure reliability, it is necessary to make the solder joint thicker to reduce the thermal strain, but as a result, the thermal resistance of the solder joint increases. There was a challenge.

Further, since the Al surface does not get wet with solder, in order to solder-join the wiring board and the heat-dissipating member made of Al, surface treatment such as plating the surface of the heat-dissipating member with Cu or Ni that is solder-wet is required. .. Further, when the metal layer of the wiring board is made of Al, surface treatment such as plating is similarly required in order to solder-bond the semiconductor elements. However, there is a problem that plating on the Al surface is difficult because an oxide film on the surface is easily formed and is dense.

Therefore, in the semiconductor device 100 of the present embodiment, the heat radiating member 1 and the wiring board 2 are joined together with a first bonding layer 10a made of Cu and a second bonding layer 10b made of Al, which have higher thermal conductivity than solder. Since it can be joined via the member 10, the thermal resistance between the heat radiating member 1 and the wiring board 2 can be reduced, and the heat resistance can be improved.

Further, in the method for manufacturing the semiconductor device 100, since the bonding member 10 having the first bonding layer 10a made of Cu and the second bonding layer 10b made of Al is used, the heat dissipation member 1 made of Al and the first metal layer made of Cu are used. It can be joined to 2b. That is, even if the heat dissipation member 1 made of Al is used, the first metal layer 2b made of Cu and the second metal layer 2c made of Cu can be used for the wiring board 2. Therefore, the semiconductor element 4 can be bonded by soldering or the like without subjecting the second metal layer 2c to a surface treatment, and as described above, a semiconductor device having reduced thermal resistance and improved heat resistance can be efficiently manufactured. It has the effect that it can.

Here, in the wiring board, from the viewpoint of moldability, the first metal layer and the second metal layer provided on both sides of the ceramic substrate as the insulating layer are usually formed of the same material. Therefore, when the second metal layer on which the semiconductor element is mounted is made of Cu in consideration of the bondability by soldering of the semiconductor element, it is required that the first metal layer is also made of Cu. That is, it is necessary to join the first metal layer made of Cu and the heat radiating member made of Al, and it is required to reduce the thermal resistance of the joined portion. Therefore, as described in the present embodiment, it is particularly effective to use the joining member 10 having the first joining layer 10a made of Cu and the second joining layer 10b made of Al.

In the present embodiment, the case where the first bonding layer 10a of the bonding member 10 is made of Cu has been described, but the first bonding layer may be made of Ni. Even in this case, the substrate portion 1a of the heat radiating member 1 and the first bonding layer of the bonding member can be solid-phase diffusion-bonded between the Al layer and the Ni layer.

Further, in the wiring substrate 2 of the present embodiment, both the first metal layer 2b and the second metal layer 2c are made of Cu, that is, the first metal layer 2b and the second metal layer 2c are made of Cu or Cu alloy, respectively. The first metal layer and the second metal layer may be made of Cu or Ni as the surface layer to be joined by the joining member 10 or the solder 3. More specifically, the first metal layer and the second metal layer include an inner layer made of Al provided on the ceramic substrate side and a surface layer made of Cu or Ni laminated on the inner layer made of Al. It can be a layered structure including. Here, the surface layer of the first metal layer is a layer that is opposite to the ceramic base material side as an insulating layer and is formed on the second bonding layer 10b side of the bonding member 10. The surface layer of the second metal layer is a layer formed on the side opposite to the ceramic base material side and on the solder 3 side to which the semiconductor element 4 is bonded. In other words, the surface layer of the first metal layer and the second metal layer of the wiring board may be at least made of Cu or Ni regardless of the layer structure.

As described above, it is desirable that the first metal layer and the second metal layer of the wiring board have a layer structure formed of the same material from the viewpoint of moldability. That is, if the first metal layer 2b is made of Cu, it is desirable that the second metal layer 2c is made of Cu. Further, if the first metal layer has a layer structure including an inner layer made of Al and a surface layer made of Cu, it is desirable that the second metal layer also has a layer structure including an inner layer made of Al and a surface layer made of Cu. If the first metal layer has a layer structure including an inner layer made of Al and a surface layer made of Ni, it is desirable that the second metal layer also has a layer structure including an inner layer made of Al and a surface layer made of Ni.

Further, the material of the first metal layer of the bonding member and the materials of the first metal layer and the second metal layer of the wiring board may be any combination, but considering the bonding conditions of solid-phase diffusion bonding, In order to enable bonding under the same conditions, the surface layer of the first metal layer and the surface layer of the second metal layer are made of Cu, that is, a single layer structure made of Cu or a layer structure in which the inner layer is an Al layer and the surface layer is made of Cu. In any case, it is desirable that the first bonding layer of the bonding member is made of Cu. For the same reason, when the surface layer of the first metal layer and the surface layer of the second metal layer are made of Ni, that is, when the inner layer is an Al layer and the surface layer is a Ni layer, the first bonding layer of the bonding member is It is desirable that it is made of Ni.

In the present embodiment, the case where the bonding member 10 is bonded by solid phase diffusion bonding has been described, but the present invention is not limited to this, and the first bonding layer made of Cu or Ni and the first bonding layer made of Al are used. It may be a semiconductor device in which the heat dissipation member and the wiring board are joined via the joining member in which the two joining layers are laminated. More specifically, it suffices that the substrate portion of the heat dissipation member is joined to the first metal layer of the joining member and the first metal layer of the wiring board is joined to the second joining layer of the joining member, respectively. It may be solid-phase diffusion bonded, or may be bonded via a brazing material or the like in between. In any case, each member is between the substrate portion of the heat dissipation member and the first joint layer of the joint member, and between the first metal layer of the wiring board and the second joint layer of the joint member. An intermetallic compound layer is formed between each other or between each member and a brazing material or the like.

Needless to say, the above-mentioned modifications of the material and the joining method can be applied to other embodiments described below.

Embodiment 2.
The semiconductor device of the second embodiment and the manufacturing method of the semiconductor device will be described with reference to FIGS. 5 to 9. FIG. 5 is a cross-sectional view showing the semiconductor device 200 of the present embodiment, and FIG. 6 is a perspective view showing a partial configuration of the semiconductor device 200. FIG. 7 is a plan view for explaining the divided structure of the joining member. Further, FIG. 8 is a cross-sectional view for explaining the first half process of the manufacturing method of the semiconductor device 200 of the present embodiment, and FIG. 9 is a cross-sectional view for explaining the second half process of the manufacturing method of the semiconductor device 200. Is.

As shown in FIGS. 5 and 6, the semiconductor device 200 of the present embodiment is different from the semiconductor device 100 of the first embodiment in that the joining member 20 has a slit 21 and is divided into a plurality of portions. .. Since the other configurations of the semiconductor device 200 are the same as those of the semiconductor device 100 of the first embodiment, the differences from the semiconductor device 100 will be mainly described below.

As shown in FIG. 5, in the semiconductor device 200, the heat radiating member 1 and the wiring board 2 are joined via the joining member 20 as in the semiconductor device 100 of the first embodiment. The joining member 20 has a first joining layer 20a made of Cu and a second joining layer 20b made of Al, and is a clad material in which these are integrally formed. Further, as shown in FIGS. 5 and 6, the joining member 20 is divided into a plurality of parts by the slits 21, and the divided joining members 22, which are the divided members, are the first joining layer 20a and the second, respectively. It has a bonding layer 20b.

Here, in the semiconductor device 200, the entire outer periphery of the joining member 20 does not necessarily have to be adhered by the adhesive 5, and the silicone gel, which is the material of the sealing material 9, is slit from the portion not filled with the adhesive 5. It can flow into 21. Further, the adhesive 5 is a silicone gel which is a material of the sealing material 9 by providing the adhesive 5 at a height lower than that of the adhesive 5 shown in FIG. 5, assuming that only the lower side of the outer periphery of the joining member 20 is adhered. May be allowed to flow into the slit 21. As described above, in the semiconductor device 200, the slit 21 which is a gap formed between the divided joining members 22 of the joining member 20 is filled with the sealing material 9. By filling the slit 21 in this way, strength and insulating properties can be ensured. The slit 21 may be filled with the adhesive 5 instead of the sealing material 9, or at least a part thereof may be hollow.

Each of the split joining members 22 has, for example, an external dimension of 19 mm × 14 mm × a thickness of 2 mm, and is arranged so that the distance between the adjacent split joining members 22, that is, the width of each of the slits 21 is 2 mm.

Here, a divided structure of the joining member 20 and a modified example thereof will be described with reference to FIG. 7.

As shown in FIGS. 7A and 6, the divided structure of the joining member 20 provided in the semiconductor device 200 of the present embodiment is a structure divided into 12 so as to have 4 columns × 3 rows in a plan view. Is. That is, the joining member 20 is composed of 12 split joining members 22. Here, as shown in FIG. 6, the second metal layer 2c of the wiring board 2 has a conductor pattern divided into six, and the semiconductor element 4 is mounted on each conductor pattern. In the semiconductor device 200 of the present embodiment, as shown in FIG. 5, the semiconductor elements 4 mounted on each conductor pattern of the second metal layer 2c are one diode and one IGBT in total. That is, each split joining member 22 is provided corresponding to the arrangement of the semiconductor element 4.

In this way, the split joining members 22 are formed so as to exist directly under the semiconductor element 4, and the slit 21 is located directly under the portion where the semiconductor element 4 does not exist, thereby reducing the heat dissipation. Thermal stress can be reduced while suppressing it. Therefore, it is desirable that the split joining member 22 is formed in a shape that is the same size as the semiconductor element 4 or larger than the semiconductor element 4 in a plan view and can cover the entire semiconductor element 4.

Further, as a first modification of the divided structure of the joining member 20, as shown in FIG. 7B, the joining member may be divided into six parts. In this case, each divided joining member is provided corresponding to the arrangement of the six-divided conductor pattern in the second metal layer of the wiring board. Even if it is formed in this way, it is desirable that the split joining member is formed directly under the semiconductor element and the slit is arranged directly under the portion where the semiconductor element does not exist. By dividing the joint member into 6 parts, the number of parts can be reduced as compared with the case of using 12 parts, that is, 12 divided joint members, so that productivity can be improved and the area occupied by the slit becomes smaller, so that heat conduction can be achieved. The property is improved and the heat dissipation can be improved.

Further, as a second modification of the divided structure of the joining member 20, as shown in FIG. 7C, the joining member is divided into 12 parts, and the structure has a connecting portion connecting between the adjacent divided joining members. good. Even in this case, it is desirable that the positional relationship with the semiconductor element is the same as that of the joining member 20 described with reference to FIG. 7 (A). In FIG. 7C, by forming the connecting portion, the number of parts of the joining member is one as a whole, so that the productivity can be improved and the area occupied by the slit becomes smaller, so that the thermal conductivity is improved. , The heat dissipation can be improved.

The above-mentioned divided structure is characterized in that the divided structure corresponds to the arrangement of the semiconductor elements in FIG. 7 (A), and in FIG. 7 (B), the conductor pattern of the second metal layer of the wiring board is used. It is characterized by the corresponding split structure. Therefore, when it is applied to a semiconductor device having a different module configuration, a divided structure corresponding to the arrangement of semiconductor elements or the conductor pattern arrangement of the second metal layer of the wiring substrate may be used, and the above-mentioned 12-divided or 6-divided structure may be used. Not limited. Further, in FIG. 7C, a structure having a connecting portion has been described, but this may be a configuration in which adjacent split joining members are connected to each other, and is not limited to 12 splits.

Next, the manufacturing method of the semiconductor device 200 will be described with reference to FIGS. 8 and 9, focusing on the differences from the semiconductor device 100 of the first embodiment.

First, as shown in FIG. 8A, the bonding member 20 is placed between the heat radiating member 1 and the wiring board 2, and the substrate portion 1a of the heat radiating member 1 and the first bonding layer 20a of the bonding member 20 face each other. , The first metal layer 2b of the wiring board 2 and the second bonding layer 20b of the bonding member 20 are arranged so as to face each other. At this time, the position is adjusted so that the gap between the divided joining members 22 of the joining member 20 is 2 mm. Then, similarly to the semiconductor device 100 of the first embodiment, the substrate portion 1a and the first bonding layer 20a are brought into contact with each other, and the surface layer of the first metal layer 2b and the second bonding layer 20b are brought into contact with each other and pressurized. By heating, the substrate portion 1a of the heat dissipation member 1 made of Al and the first bonding layer 20a made of Cu are solid-phase diffusion bonded, and at the same time, the first metal layer 2b made of Cu and the second bonding layer made of Al are bonded. Solid-phase diffusion bonding with 20b is performed.

Then, as shown in FIG. 8B, the semiconductor element 4 is bonded onto the second metal layer 2c, which is the conductor layer of the wiring board 2, by using the solder 3. In this way, as shown in FIG. 8C, the semiconductor element 4 is joined and provided on the wiring board 2.

Next, as shown in FIG. 9A, the case 6 in which the main terminal 7a and the signal terminal 7b are insert-molded is subjected to the same as the semiconductor device 100 of the first embodiment, using the silicone adhesive 5. Glue.

After that, as shown in FIG. 9B, the main terminal 7a and the semiconductor element 4 are wired by a wire 8a using a wire bonder to form a main power circuit. Further, the signal terminal 7b and the semiconductor element 4 are wired by a wire 8b using a wire bonder to form a signal circuit.

Finally, as shown in FIG. 9C, the silicone gel is injected into the inside of the case 6 and heated to be cured to perform insulation sealing as the sealing material 9. At this time, by injecting the silicone gel while evacuating, the silicone gel can be filled without voids, and the slit 21 between the split joining members 22 can also be filled with the silicone gel. In this way, the semiconductor device 200 is completed.

In the method of manufacturing the semiconductor device 200 and the semiconductor device 200 configured as described above, in addition to the same effect as the method of manufacturing the semiconductor device 100 and the semiconductor device 100 of the first embodiment, the joining member 20 is divided. This has the effect of further reducing the thermal stress at the joint between the heat radiating member 1 and the wiring board 2.

Further, in the method of manufacturing the semiconductor device 200 and the semiconductor device 200 of the present embodiment, since the joint member 20 is divided, air can escape from the slit 21, and air is trapped in the joint portion and exists as a void. It has the effect of suppressing the use of air.

Embodiment 3.
The semiconductor device of the third embodiment will be described with reference to FIGS. 10 and 11. FIG. 10 is a cross-sectional view showing a partial configuration according to the first example of the semiconductor device of the present embodiment, and FIG. 11 shows a partial configuration according to the second example of the semiconductor device of the present embodiment. It is sectional drawing which shows.

In the semiconductor device of the present embodiment, as shown in FIG. 10 or 11, the thickness of each of the divided joining members 32, 33 of the joining member 30 is formed so as to correspond to the warp of the wiring board 2. , Different from the semiconductor device 200 of the second embodiment. Since other configurations of the semiconductor device of the present embodiment are the same as those of the semiconductor device 200 of the second embodiment, the differences from the semiconductor device 200 will be mainly described below.

In the semiconductor device of the present embodiment, as shown in FIGS. 10 and 11, the heat radiating member 1 and the wiring board 2 are joined via the joining member 30 as in the semiconductor device 200 of the second embodiment. There is. The joining member 30 has a first joining layer 30a made of Cu and a second joining layer 30b made of Al, and is a clad material in which these are integrally formed. Further, the joining member 30 is divided into a plurality of parts by the slit 31, and the divided joining members 32 and 33, which are the divided members, have the first joining layer 30a and the second joining layer 30b, respectively.

First, the first example will be described with reference to FIG. The first example is a case where the wiring board 2 is warped so as to be convex downward. The warp of the wiring board 2 is caused by heating when joining by solid phase diffusion joining or the like. Therefore, among the split joining members 32 and 33 constituting the joining member 30 so as to follow the downward warp of the wiring board 2, the thickness A of the split joining member 32 provided on the outer peripheral portion is the split joining member 32. It is formed so as to be larger than the thickness B of the split joining member 33 provided in the central portion inside.

More specifically, for example, by setting the thickness A of the split joining member 32 in the outer peripheral portion to 2.2 mm and the thickness B of the split joining member 33 in the central portion to 1.8 mm, the warp of the wiring board 2 can be obtained. Follow-up joining is possible. Further, at this time, it is preferable to form the second bonding layer 30b of the bonding member 30 with JIS A1000 series pure aluminum because the second bonding layer 30b is easily deformed so as to follow the warp.

Next, the second example will be described with reference to FIG. The second example is a case where the wiring board 2 is warped so as to be convex upward. Therefore, among the split joining members 32 and 33 constituting the joining member 30 so as to follow the upward warp of the wiring board 2, the thickness A of the split joining member 32 provided on the outer peripheral portion is the split joining member 32. It is formed so as to be smaller than the thickness B of the split joining member 33 provided in the central portion inside.

More specifically, for example, by setting the thickness A of the split joining member 32 in the outer peripheral portion to 1.8 mm and the thickness B of the split joining member 33 in the central portion to 2.2 mm, the warp of the wiring board 2 can be obtained. Follow-up joining is possible. Further, at this time, it is preferable to form the second bonding layer 30b of the bonding member 30 with JIS A1000 series pure aluminum because the second bonding layer 30b is easily deformed so as to follow the warp.

In the method for manufacturing the semiconductor device and the semiconductor device according to the present embodiment configured as described above, in addition to the same effects as the method for manufacturing the semiconductor device 200 and the semiconductor device 200 according to the second embodiment, the joining member 30 Can be joined by following the warp of the wiring board 2, so that the bondability can be further improved.

In the present embodiment, the case where the thickness of the split joining member is different between the outer peripheral portion and the central portion so as to follow the warp of the wiring board 2 has been described, but the bonding property is deteriorated by applying pressure at the time of joining. If not, it is possible to join to a wiring board in which warpage occurs even if the thicknesses of the split joining members are all the same.

Embodiment 4.
A semiconductor device according to the fourth embodiment and a method for manufacturing the semiconductor device will be described with reference to FIGS. 12 and 13. FIG. 12 is a cross-sectional view showing the semiconductor device 400 of the present embodiment. Further, FIG. 13 is a cross-sectional view for explaining the manufacturing method of the semiconductor device 400 of the present embodiment.

In the semiconductor device 400 of the present embodiment, as shown in FIG. 12, the semiconductor element 4 is joined to the main terminals 41 and 42 via the solder 43 to form a main power circuit. It is different from the semiconductor device 200 of. Since the other configurations of the semiconductor device 400 are the same as those of the semiconductor device 200 of the second embodiment, the differences from the semiconductor device 200 will be mainly described below.

In the semiconductor device 400, similarly to the semiconductor device 200 of the second embodiment, the heat radiating member 1 and the wiring board 2 are joined via a joining member 20 composed of a plurality of split joining members 22. The semiconductor device 400 does not use wires to form the circuit of the main power circuit, and the main power circuit is formed by soldering the main terminals 41 and 42 attached to the case 6 by insert molding onto the semiconductor element 4. Has been done. Further, the semiconductor element 4 is not only electrically bonded to the main terminals 41 and 42, but also wire-bonded to a signal terminal (not shown) insert-molded in the case 6.

Next, the manufacturing method of the semiconductor device 400 will be described with reference to FIG. 13, focusing on the differences from the semiconductor device 200 of the second embodiment.

First, as shown in FIG. 13A, similarly to the semiconductor device 200 of the second embodiment, the joining member 20 is provided between the heat radiating member 1 and the wiring board 2, and the gaps between the divided joining members 22 are formed. Adjust and arrange so that it is 2 mm. Then, the substrate portion 1a and the first bonding layer 20a are brought into contact with each other, and the surface layer of the first metal layer 2b and the second bonding layer 20b are brought into contact with each other and heated while pressurizing to obtain the heat radiation member 1 made of Al. The first bonding layer 20a made of Cu is solid-phase diffusion bonded, and at the same time, the first metal layer 2b made of Cu and the second bonding layer 20b made of Al are solid-phase diffusion bonded.

Then, as shown in FIG. 13B, the semiconductor element 4 is bonded onto the second metal layer 2c, which is the conductor layer of the wiring board 2, by using the solder 3. In this way, as shown in FIG. 13C, the semiconductor element 4 is joined and provided on the wiring board 2.

Next, as shown in FIG. 13 (D), the case 6 in which the main terminals 41 and 42 and the signal terminal (not shown) are insert-molded is bonded to each other using a silicone adhesive 5. At this time, the case 6 is adhered, and the plate-shaped solder 43 is sandwiched between the upper surface of the semiconductor element 4 and the main terminals 41 and 42. Then, the main terminals 41 and 42 and the semiconductor element 4 are joined by melting the solder 43 to form a main power circuit. Further, the signal terminal (not shown) and the semiconductor element 4 are wired with a wire made of Al (not shown) using a wire bonder to form a signal circuit.

Finally, as shown in FIG. 13 (E), the silicone gel is injected into the inside of the case 6 and heated and cured to perform insulation sealing as the sealing material 9. In this way, the semiconductor device 400 is completed.

Even in the method of manufacturing the semiconductor device 400 and the semiconductor device 400 configured in this way, the same effect as the manufacturing method of the semiconductor device 200 and the semiconductor device 200 of the second embodiment can be obtained.

Embodiment 5.
The semiconductor device of the fifth embodiment and the manufacturing method of the semiconductor device will be described with reference to FIGS. 14 to 16. FIG. 14 is a cross-sectional view showing the semiconductor device 500 of the present embodiment. Further, FIG. 15 is a cross-sectional view for explaining the first half process of the manufacturing method of the semiconductor device 500 of the present embodiment, and FIG. 16 is a cross-sectional view for explaining the second half process of the manufacturing method of the semiconductor device 500. Is.

As shown in FIG. 14, the semiconductor device 500 of the present embodiment is different from the semiconductor device 200 of the second embodiment in that it does not have a case and has a transfer-molded structure. Since the other configurations of the semiconductor device 500 are the same as those of the semiconductor device 200 of the second embodiment, the differences from the semiconductor device 200 will be mainly described below.

In the semiconductor device 500, similarly to the semiconductor device 200 of the second embodiment, the heat radiation member 1 and the wiring board 2 are joined via a joining member 20 composed of a plurality of split joining members 22. The semiconductor device 500 does not have a case, and has a structure in which the sealing material 51 is molded by a transfer mold and insulated and sealed.

Here, in the semiconductor device 500, as in the semiconductor device 200 of the second embodiment, it is not always necessary that the entire outer periphery of the joining member 20 is adhered by the adhesive 5, and the semiconductor device 500 is not filled with the adhesive 5. The resin material constituting the sealing material 51 can flow into the slit 21. In this way, in the semiconductor device 500, the slit 21 which is a gap formed between the divided joining members 22 of the joining member 20 is filled with the sealing material 51.

Further, since the semiconductor device 500 does not have a case, the main terminal 7a and the signal terminal 7b have a structure in which the main terminal 7a and the signal terminal 7b are bonded and fixed to the heat radiating member 1, the wiring board 2, and the joining member 20 by the silicone adhesive 5. It has become. Further, the main terminal 7a and the signal terminal 7b are a part of the lead frame.

Next, the manufacturing method of the semiconductor device 500 will be described with reference to FIGS. 15 and 16, focusing on the differences from the semiconductor device 200 of the second embodiment.

First, as shown in FIG. 15A, similarly to the semiconductor device 200 of the second embodiment, the joining member 20 is provided between the heat radiating member 1 and the wiring board 2, and the gaps between the divided joining members 22 are formed. Adjust and arrange so that it is 2 mm. Then, the substrate portion 1a and the first bonding layer 20a are brought into contact with each other, and the surface layer of the first metal layer 2b and the second bonding layer 20b are brought into contact with each other and heated while pressurizing to obtain the heat radiation member 1 made of Al. The first bonding layer 20a made of Cu is solid-phase diffusion bonded, and at the same time, the first metal layer 2b made of Cu and the second bonding layer 20b made of Al are solid-phase diffusion bonded.

Then, as shown in FIG. 15B, the semiconductor element 4 is bonded onto the second metal layer 2c, which is the conductor layer of the wiring board 2, by using the solder 3. In this way, as shown in FIG. 15C, the semiconductor element 4 is joined and provided on the wiring board 2.

Next, as shown in FIG. 15 (D), a Cu lead frame having a thickness of, for example, 0.6 mm including a main terminal 7a and a signal terminal 7b is attached to a heat dissipation member 1 using a silicone adhesive 5. Adhere to the wiring board 2 and the joining member 20. At this time, for example, it is heated at 140 ° C. for 10 minutes.

After that, as shown in FIG. 16A, the main terminal 7a and the semiconductor element 4 are wired by a wire 8a using a wire bonder to form a main power circuit. Further, the signal terminal 7b and the semiconductor element 4 are wired by a wire 8b using a wire bonder to form a signal circuit.

Finally, as shown in FIG. 16 (B), the entire mold is sandwiched between the upper mold 91 and the lower mold 92, and the transfer mold resin is injected and cured to perform insulation sealing, and FIG. 16 (C). ), The semiconductor device 500 insulated and sealed by the sealing material 51 is completed.

Even in the method of manufacturing the semiconductor device 500 and the semiconductor device 500 configured in this way, the same effect as the manufacturing method of the semiconductor device 200 and the semiconductor device 200 of the second embodiment can be obtained.

Embodiment 6.
The power conversion device of the sixth embodiment, which is equipped with the semiconductor device according to any one of the above-described embodiments 1 to 5, will be described with reference to FIG. FIG. 17 is a block diagram for explaining the power conversion device of the present embodiment, and FIG. 17 as a whole shows a power conversion system to which the power conversion device of the present embodiment is applied. Hereinafter, the case where the sixth embodiment is a three-phase inverter will be specifically described.

The power conversion system shown in FIG. 17 includes the power conversion device 600, the power supply 610, and the load 620 of the present embodiment. The power supply 610 is a DC power supply and supplies DC power to the power conversion device 600. The power supply 610 can be configured with various things, for example, it can be configured with a DC system, a solar cell, a storage battery, or it can be configured with a rectifier circuit or an AC / DC converter connected to an AC system. May be good. Further, the power supply 610 may be configured by a DC / DC converter that converts the DC power output from the DC system into a predetermined power.

The power conversion device 600 is a three-phase inverter connected between the power supply 610 and the load 620, converts the DC power supplied from the power supply 610 into AC power, and supplies AC power to the load 620. As shown in FIG. 17, the power conversion device 600 converts the input DC power into AC power and outputs the main conversion circuit 601 and outputs the control signal for controlling the main conversion circuit 601 to the main conversion circuit 601. It is provided with a control circuit 603.

The load 620 is a three-phase electric motor driven by AC power supplied from the power converter 600. The load 620 is not limited to a specific application, and is an electric motor mounted on various electric devices. For example, the load 620 is used as an electric motor for a hybrid vehicle, an electric vehicle, a railroad vehicle, an elevator, or an air conditioner.

Hereinafter, the details of the power conversion device 600 of the present embodiment will be described. The main conversion circuit 601 includes a switching element and a freewheeling diode (not shown), and by switching the switching element, the DC power supplied from the power supply 610 is converted into AC power and supplied to the load 620. .. There are various specific circuit configurations of the main conversion circuit 601. The main conversion circuit 601 according to the present embodiment is a two-level three-phase full bridge circuit, and has six switching elements and each switching element. It can consist of six anti-parallel freewheeling diodes. The semiconductor device according to any one of the above-described embodiments 1 to 5 is applied to at least one of each switching element and each freewheeling diode of the main conversion circuit 601. The six switching elements are connected in series for each of the two switching elements to form an upper and lower arm, and each upper and lower arm constitutes each phase (U phase, V phase, W phase) of the full bridge circuit. Then, the output terminals of each upper and lower arm, that is, the three output terminals of the main conversion circuit 601 are connected to the load 620.

Further, although the main conversion circuit 601 includes a drive circuit (not shown) for driving each switching element, the drive circuit may be built in the semiconductor device 602, or a drive circuit may be provided separately from the semiconductor device 602. It may be provided. The drive circuit generates a drive signal for driving the switching element of the main conversion circuit 601 and supplies it to the control electrode of the switching element of the main conversion circuit 601. Specifically, according to the control signal from the control circuit 603 described later, a drive signal for turning on the switching element and a drive signal for turning off the switching element are output to the control electrode of each switching element. When the switching element is kept on, the drive signal is a voltage signal (on signal) equal to or higher than the threshold voltage of the switching element, and when the switching element is kept off, the drive signal is a voltage equal to or lower than the threshold voltage of the switching element. It becomes a signal (off signal).

The control circuit 603 controls the switching element of the main conversion circuit 601 so that the desired power is supplied to the load 620. Specifically, the time (on time) in which each switching element of the main conversion circuit 601 should be in the on state is calculated based on the electric power to be supplied to the load 620. For example, the main conversion circuit 601 can be controlled by PWM control that modulates the on-time of the switching element according to the voltage to be output. Then, a control command (control signal) is output to the drive circuit provided in the main conversion circuit 601 so that an on signal is output to the switching element that should be turned on at each time point and an off signal is output to the switching element that should be turned off. Is output. The drive circuit outputs an on signal or an off signal as a drive signal to the control electrode of each switching element according to this control signal.

In the power conversion device of the present embodiment, since the semiconductor device according to any one of the first to fifth embodiments is applied to at least one of the switching element and the freewheeling diode of the main conversion circuit 601, the thermal resistance is reduced and the heat resistance is reduced. It has the effect of improving sex.

In this embodiment, an example of application to a two-level three-phase inverter has been described, but the present invention is not limited to this, and can be applied to various power conversion devices. In the present embodiment, a two-level power conversion device is used, but a three-level or multi-level power conversion device may be used, and when supplying power to a single-phase load, it is applied to a single-phase inverter. It doesn't matter. Further, when supplying electric power to a DC load or the like, it is also possible to apply this embodiment to a DC / DC converter or an AC / DC converter.

Further, the power conversion device of the present embodiment is not limited to the case where the load described above is an electric motor, and is, for example, a power supply device of an electric discharge machine, a laser machine, an induction heating cooker, or a non-contact power supply system. It can also be used as a power conditioner for a photovoltaic power generation system, a power storage system, or the like.

It should be noted that it is also included in the scope of the present disclosure that each embodiment is appropriately combined, modified or omitted.

1 heat dissipation member, 2 wiring board, 2a ceramic base material (insulating layer), 2b first metal layer, 2c second metal layer, 4 semiconductor element,
10, 20, 30 joining members, 10a, 20a, 30a first joining layer, 10b, 20b, 30b second joining layer, 21, 31 slits, 22, 32, 33 split joining members,
100, 200, 400, 500, 602 semiconductor devices,
600 power converter, 601 main converter circuit, 603 control circuit

Claims (14)

A heat dissipation member with a flat plate-shaped substrate and
A first joining layer provided on the substrate portion of the heat radiating member, and a joining member having a second joining layer provided on the first joining layer.
A wiring board having a first metal layer provided on the second joining layer of the joining member, an insulating layer provided on the first metal layer, and a second metal layer provided on the insulating layer. ,
A semiconductor element provided on the second metal layer of the wiring board is provided.
The substrate portion of the heat radiating member and the second bonding layer of the bonding member are formed of Al or an Al alloy.
At least the surface layer of the first metal layer of the wiring board on the side of the second bonding layer and the first bonding layer of the bonding member are made of Cu or Cu alloy, or Ni or Ni alloy. A featured semiconductor device. Between the substrate portion of the heat radiating member and the first bonding layer of the bonding member, and between the second bonding layer of the bonding member and the first metal layer of the wiring board, there are intermetallic spaces. The semiconductor device according to claim 1, wherein a compound layer is formed. The joining member is composed of a plurality of split joining members.
The semiconductor device according to claim 1 or 2, wherein each of the split joining members has the first joining layer and the second joining layer. The semiconductor device according to claim 3, wherein each of the split joining members is provided directly below the semiconductor element. A plurality of the semiconductor elements are provided, and the semiconductor element is provided.
The joining member is composed of the same number of the split joining members as the semiconductor element.
The semiconductor device according to claim 3 or 4, wherein each of the split joining members is provided corresponding to the arrangement of the semiconductor elements. The second metal layer of the wiring board is composed of a plurality of conductor patterns.
The joining member is composed of the same number of the split joining members as the conductor pattern.
The semiconductor device according to claim 3 or 4, wherein each of the split joining members is provided corresponding to the arrangement of the conductor pattern. The semiconductor device according to any one of claims 3 to 6, wherein the joining member has a connecting portion that connects adjacent split joining members. Claims 3 to 7 are characterized in that the thickness of the split joining member provided on the outer peripheral portion and the thickness of the split joining member provided on the inner side of the outer peripheral portion of the joining member are different. The semiconductor device according to any one of the following items. The semiconductor device according to any one of claims 1 to 8, wherein the first metal layer of the wiring board and the first bonding layer of the bonding member are formed of Cu or a Cu alloy. .. The first metal layer of the wiring substrate has a layer structure in which the inner layer on the insulating layer side is formed of Al or Al alloy, and the surface layer laminated on the inner layer is formed of Cu or Cu alloy.
The semiconductor device according to any one of claims 1 to 8, wherein the first bonding layer of the bonding member is formed of Cu or a Cu alloy. The first metal layer of the wiring substrate has a layer structure in which the inner layer on the insulating layer side is formed of Al or Al alloy, and the surface layer laminated on the inner layer is formed of Ni or Ni alloy.
The semiconductor device according to any one of claims 1 to 8, wherein the first bonding layer of the bonding member is formed of Ni or a Ni alloy. The first step of joining the substrate portion of the heat radiating member and the first joining layer of the joining member having the first joining layer and the second joining layer provided on the first joining layer.
A wiring board having the second bonding layer of the bonding member, an insulating layer, a first metal layer provided on one surface of the insulating layer, and a second metal layer provided on the other surface of the insulating layer. A second step of joining the first metal layer and
A third step of joining the second metal layer of the wiring board and the semiconductor element is included.
The substrate portion of the heat radiating member and the second bonding layer of the bonding member are formed of Al or an Al alloy.
At least the surface layer on the opposite side of the insulating layer side of the first metal layer of the wiring board and the first bonding layer of the bonding member are formed of Cu or Cu alloy, or Ni or Ni alloy. A method for manufacturing a semiconductor device. The first step and the second step are performed at the same time, and the substrate portion and the first bonding layer are brought into contact with each other, and the second bonding layer and the surface layer of the first metal layer are brought into contact with each other. The method for manufacturing a semiconductor device according to claim 12, wherein the bonding is performed by heating while pressing. A main conversion circuit having the semiconductor device according to any one of claims 1 to 11 and converting and outputting input power.
A control circuit that outputs a control signal that controls the main conversion circuit to the main conversion circuit, and a control circuit that outputs the control signal to the main conversion circuit.
Power conversion device equipped with.

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