JP5069587B2 - Circuit equipment - Google Patents

Description

  The present invention relates to a circuit device for mounting a power semiconductor element.

In a conventional circuit device that controls a large current and voltage, the loss of semiconductor elements and electronic components is large, and these must be cooled. Therefore, these electronic components are mounted on a metal substrate made of a metal with high heat dissipation and a thin resin insulating layer, and are cooled by dissipating heat from a heat sink attached to the back side of these substrates via grease or adhesive. It was a structure. As a substrate on which electronic components are mounted, for example, a ceramic substrate in which a metal foil is bonded to alumina or aluminum nitride, which has a higher thermal conductivity than resin, is generally used.
When a semiconductor element or an electronic component is mounted on the substrate and the wiring is routed, the substrate area increases. For example, as in Patent Document 1, the semiconductor element is fixed to the radiator via an insulating sheet, and from the semiconductor element. There is a method of connecting wires in a three-dimensional manner by connecting the leads to the bus bar structure above the semiconductor element.

Japanese Unexamined Patent Publication No. 2004-190525 (FIG. 1)

In the circuit device described in Patent Document 1, since the semiconductor element is fixed side by side with respect to the heat radiating surface of the radiator, the area occupied by the semiconductor element increases as the number of mounted semiconductor elements increases. There is a concern that the device will become large. In addition, when wiring between semiconductor elements is required, the wiring is performed via a bus bar structure. Therefore, depending on the amount of current, the wiring loss may increase, and the efficiency of the circuit device may decrease or the temperature may increase excessively. .
In addition, since the semiconductor element is attached to the radiator through an insulating sheet having a large thermal resistance, the temperature of the semiconductor element is greatly increased, leading to an increase in the temperature inside the housing that is housed. There is a possibility that the thermal stress of the soldered portion of the electronic component is increased, and further, the efficiency of the circuit device is deteriorated.
The present invention has been made to solve the above-described problems, and provides a compact circuit device.

According to another aspect of the present invention, there is provided a circuit device comprising: a lead element derived from the inside of a main body; a semiconductor element having an exposed electrode; a heat radiating part that is cooled by being exposed to a coolant; and a conductive part on which the electrode of the semiconductor element is mounted. A conductive and heat radiating plate, an insulating frame portion for holding a plurality of conductive and heat radiating plates on which the semiconductor elements are mounted at predetermined intervals, and a connection terminal for the lead terminal and the electrode formed on the conductive portion. A circuit unit that is connected to each other to form a predetermined circuit is provided. A plurality of the semiconductor elements are mounted on a single conductive / heat radiating plate and connected in parallel to each other. The semiconductor elements mounted in parallel are connected in series by the circuit unit,
The heat radiating portion of the conductive / heat radiating plate portion is covered with an insulating cover and cooled with a refrigerant .

According to the circuit device of the present invention, since one conductive plate has both the heat radiating portion and the conductive portion, the number of members is small, and a very compact circuit device can be realized. In particular, since the semiconductor elements can be arranged vertically and arranged, the area for housing the semiconductor elements can be small, so that a very compact circuit device can be manufactured.
In addition, since the heat dissipating part and the conductive part are integrally formed, the semiconductor element is directly mounted on the heat dissipating part without an insulating layer, so that the cooling performance is excellent, and further, the electric resistance of the conductive plate is reduced. Therefore, the wiring loss can be reduced, the temperature rise can be reduced, and the efficiency of the circuit device can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, the same code | symbol shows the same or an equivalent part between each figure.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view schematically showing a circuit device for explaining the first embodiment.
In FIG. 1, a semiconductor element 2 having an electrode (hereinafter referred to as “electrode part”) 201 exposed on the surface has the electrode part 201 as a main surface of a conductive part 3 of a conductive and heat radiating plate (hereinafter referred to as “plate”) 1. (Semiconductor element 2 mounting surface) 3a is joined by soldering.
The plate 1 is made of a conductive material such as metal, and has a heat radiating portion (described later) 6 that is cooled by being exposed to a refrigerant in addition to the conductive portion 3 described above, and is mounted on the plate 1 and the plate. The plate portion 101 is constituted by the semiconductor element 2.
The plurality of plates 1 are attached and held from above or below to an insulating frame portion 10a made of an insulating material such as resin, and are arranged (arranged) at a predetermined interval. The plurality of plates 1 are aligned and arranged so that the main surface 3a on which the semiconductor element 2 is mounted is in the same direction.

The semiconductor element 2 is mounted with a device (not shown) on the surface opposite to the back surface of the electrode part 201 and molded with resin, and the inside of the device (inside the main body) and the outside are electrically connected from at least one surface of the semiconductor element 2. A lead terminal group (lead terminal) 4 to be connected protrudes (leads out), and the lead terminal group 4 is connected to a plate 1 a adjacent to the plate 1, for example.
Further, relay terminals 5 for electrical drawing are arranged above the plate portion 101 and connected to the control board 7.
The lower part of the plate 1 on which the main surface 3a on which the semiconductor element 2 is mounted extends downward forms a heat radiating part (heat radiating part) 6 and also serves as a heat radiating member that cools the semiconductor element 2 by being exposed to the refrigerant. The refrigerant may be a gas such as air forcibly blown by a fan, a gas such as air flowing by natural convection, or a liquid such as water or a coolant material.

  The entire circuit device is protected by covering with a lid 10b from the top, and the bottom plate 10c from which the plate 1 protrudes is also provided at the bottom to protect the inside of the device. The inside of the apparatus may be filled with a resin for protection. Therefore, the insulating frame portion 10a includes a lid 10b, a bottom plate 10c, and the like.

The semiconductor elements 2 mounted on the respective plates 1 arranged in parallel as shown in FIG. 1 are connected in series, and a heat radiation portion 6 is provided for each semiconductor element 2 connected in series to be exposed to the refrigerant. This ensures heat dissipation performance.
A current from the electrode part 201 of the semiconductor element 2 flows through the plate 1. On the other hand, when a wiring board is used as in the conventional case, the pattern on the board has a small cross-sectional area of the wiring, so the wiring loss is large, the efficiency of the circuit device is deteriorated, and the cooling for exhaust heat is enhanced. There is a need to. On the other hand, since the plate 1 has a large cross-sectional area, the electrical resistance can be kept small and the wiring loss is reduced.
Moreover, since the semiconductor element 2 is mounted on the plate 1 as a heat dissipation member by soldering with the electrode portion 201 provided on the back surface, the thermal resistance is small and high cooling performance can be realized. Furthermore, the plate 1 has both a conductive member and a heat radiating member, so that another member such as a heat sink is not required, and an inexpensive, small and light circuit device can be realized.

  For example, in a circuit device for controlling a power supply system for automobiles, a low-voltage MOSFET may be used as a semiconductor element, and since the on-resistance is very low, sufficient heat dissipation can be achieved simply by using the surface of a flat conductive plate as a heat dissipation part. Sex can be secured. In addition, the small loss of the circuit device improves the efficiency and greatly improves the fuel efficiency of the automobile, and contributes significantly to the environment.

If the plate 1 is made of a material such as copper or aluminum, the electric conductivity is large and the plate 1 can be more efficient. In the case of aluminum, it is possible to ensure the corrosion resistance of the heat dissipating part exposed to the outside air by applying nickel plating to solder the semiconductor element 2.
On the other hand, when the amount of current is larger or when the loss of the semiconductor element 2 is larger, for example, as shown in FIG. If the heat area is increased, the heat radiation amount of the heat radiation part 6b increases, and the temperature rise can be suppressed. In particular, if the plate 1c is manufactured from copper, a copper alloy, aluminum, or an aluminum alloy, the fin portion 24 can be easily and integrally provided on the plate 1c by a method such as forging. Furthermore, if it is aluminum and an aluminum alloy, a fin part can be easily provided in a plate by die-casting easily.
In such a circuit device, the area in which the semiconductor elements 2 are arranged is reduced by arranging the plurality of semiconductor elements 2 in a vertical shape. Therefore, particularly in a circuit device in which a large number of semiconductor elements 2 are arranged, it is possible to reduce the size. The effect is remarkably large.

  By the way, in the case of this Embodiment 1, the plate 1 is a conductor, and in the state which does not process anything on the surface, a thermal radiation site | part has an electric potential. Therefore, the distance between the plates is determined in accordance with the voltage specifications of the circuit device to ensure insulation. In addition, the heat-dissipating part exposed from below the circuit device so that the plates are exposed to the refrigerant can be reduced in the distance between the plates, for example, by performing chemical treatment such as alumite treatment or treatment for covering the insulating layer. Insulation can be avoided due to adhesion of foreign substances.

FIG. 3 is a perspective view for explaining each plate portion 101 constituting the power portion (circuit portion).
The plate 1 has a main surface 3a on which the semiconductor element 2 is mounted, a terminal portion 8 that is bent and extended in an L shape from the main surface 3a, and a flange portion 9 that is formed so as to extend on both sides of the main surface 3a.
FIG. 4 is a perspective view specifically showing the plate portion 101 where the semiconductor element 2 is attached to the plate 1, and the electrode portion 201 is formed on one surface of the semiconductor element 2 as described above. 201 is soldered to the plate 1.
A lead terminal group 4 including main current lead terminals 4a and signal terminals 4b protrudes from another surface of the semiconductor element 2, and is in a linearly different direction from the terminal portion 8 bent into an L shape of the plate 1. Bend into an L shape. On the other hand, the terminal portion 8 of the plate is divided so that the main current lead terminal of the semiconductor element mounted on the plate adjacent to the power portion arranged in parallel is connected.
The plate 1 in the first embodiment is configured such that three semiconductor elements are mounted, and the terminal portion 8 of the plate has two main currents output from the semiconductor elements 2 mounted on the adjacent plates. Three terminal portions 8 divided into two are provided so that the lead terminals 4a are connected.
In this way, the semiconductor elements mounted on the same plate form a circuit that distributes the current flowing through the circuit device in parallel with each other and is connected in series with the semiconductor elements between adjacent plates. A circuit portion is formed.

FIG. 5 is a schematic view of the power unit as viewed from above.
FIG. 4 shows a unit portion in which three semiconductor elements 2 are connected in parallel. However, the number of semiconductor elements 2 that can be mounted is one as shown in FIG. It may be.
In the plate portion 102 of FIG. 5, three semiconductor elements 2a, 2b, and 2c are mounted, and these semiconductor elements 2 are connected in parallel. On the other hand, in the plate portion 103, one semiconductor element 21 is mounted, and the semiconductor element 2 in the plate portion 102 and the semiconductor element 2 in the plate portion 103 are connected in series.
As described above, the number of semiconductor elements may vary depending on the circuit specifications. In any case, the plate portion 101 on which various numbers of semiconductor elements 2 are mounted using the same shape plate. , 102,... Are arranged in a column or a row (described later), and it is only necessary to manufacture a single plate 1, so that productivity can be improved and industrial value is increased.

  Further, as shown in FIG. 6, the plurality of plate portions 101, 102,... On which the semiconductor element 2 is mounted have the main surface 3a in the same direction as described above with reference to the insulating frame 10a made of an insulating material such as resin. It is attached to become. A plurality of openings 11 arranged in alignment with the plate portion 102 are formed in the insulating frame 10a. Further, the semiconductor element 2 according to the first embodiment is different from the main current lead terminal 4a connected to the adjacent plates 1 and 1a as described with reference to FIG. And a relay terminal 5c connected to the control board 7 is attached to the insulating frame 10a, and the signal terminal 4b and the relay terminal 5c are connected to each other.

  As a method for attaching the relay terminal 5c, if the relay terminal 5c is inserted and molded in advance during resin molding of the insulating frame 10a, an installation space and attachment parts are not required and the size can be reduced. At the time of attachment, a method such as screwing may be used, and the plate portions 101, 102... May be bonded to the insulating frame 10a. If a fitting portion (not shown) is formed in advance on either or both of the insulating frame side and the plate portion side and press-fitted and fixed, members such as screws and adhesives become unnecessary.

  Further, by fixing a plurality of plate portions 101, 102,... On which the semiconductor element 2 is mounted to the insulating frame 10a, the number of parts to be inserted into the insulating frame 10a can be reduced, and the manufacturing of the insulating frame 10a is facilitated. Further, it is not necessary to mount the semiconductor element 2 on the conductive portion having a complicated three-dimensional shape, and mounting is easy. In particular, the manufacturing cost is reduced by manufacturing a large number of similar plate portions in which the semiconductor element 2 is mounted on the plate 1.

In the first embodiment, the plate portion 101 includes three semiconductor elements 2 mounted in parallel on each plate 1, and three relay terminals 5c are provided side by side for each plate portion. ing. In the lead terminal group 4 of the semiconductor element, the main current lead terminal 4a is connected to the terminal portion 8 divided into two adjacent plates, and the signal terminal 4b is connected to an end portion of the relay terminal 5c bent into an L shape. The
The lead terminal group 4 and the plate terminal portion 8 and the L-shaped end of the relay terminal 5c can be connected by methods such as soldering, resistance welding, arc welding, ultrasonic bonding, and caulking. When laser welding is performed as shown in FIG. 7, a member for joining becomes unnecessary, and the space around the lead terminal can be reduced, which contributes to making the circuit device compact.

Next, an example in which the lead terminal group 4, the plate terminal portion 8, and the relay terminal 5 are joined by laser welding will be described with reference to a schematic diagram shown in FIG.
The beam exit ends 13a and 13b are positioned below the plate portion 101 or above the relay terminal 5a, and are welded by irradiating lasers 14a and 14b. A plurality of welded portions 15 can be continuously welded in a short time by moving the beam emission ports 13a and 13b.

  When these members are welded, it is possible to perform welding with a small irradiation energy by irradiating from the smaller of the lead terminal thickness and the plate terminal portion or the relay terminal thickness. Therefore, the irradiation direction may be appropriately selected. Further, when the plate part 101 is attached to the insulating frame part 10a, if the lead terminals 4a and 4b and the plate terminal part 8 or the relay terminal 5a are pressed against each other autonomously, there is no pressing tool or the like. However, heat conduction during welding is good through the joint interface, and a good weld can be formed. For example, the lead terminal group 4, the plate terminal portion 8, and the relay terminal 5 a may be provided with a vent structure.

Embodiment 2. FIG.
FIG. 8 is a schematic diagram illustrating a circuit configuration according to the second embodiment and a configuration in which a plurality of power units described in FIG. 5 are combined.
In the second embodiment, the plates 1e to 1j are arranged not only in parallel with the main surface 3a but also in the horizontal direction of the main surface 3a.
The semiconductor elements mounted on the plates 1e to 1j vertically adjacent to the main surface 3a, that is, the semiconductor elements 2d to 2i mounted on the plates 1e to 1j are connected in series, while adjacent to the main surface 3a in the horizontal direction. The plates, for example, 1g, 1k, and 1L, are fastened and connected by the flange portion 9b having the same function as described in FIG. 3, and are mounted on the semiconductor elements mounted on these plates, that is, the plates 1g, 1k, and 1L. The semiconductor elements 2f, 2j, and 2k are conductively and thermally conductively connected in parallel at the flange portion integrated with the plate, thereby achieving thermal dispersion and improving heat dissipation. Further, the flange portion 9b is offset by the thickness of the plate so that the main surfaces 3a of the adjacent plates are in the same plane.

  Thus, since it can connect in parallel by the flange part 9b, even if it is a case where the semiconductor element 2 is a circuit structure by both series and parallel, the plate member of the same shape can be used and the kind of components is Less productive. Further, since the circuit can be configured by freely arranging the same plate portions in series and parallel as in the second embodiment, even if it is a multi-type circuit device, it can be manufactured with the same combination of members. Industrial value is high for multi-product production.

Embodiment 3 FIG.
FIG. 9 is a cross-sectional view schematically showing a circuit device for explaining the third embodiment.
The third embodiment is a circuit device that combines a series-parallel circuit of semiconductor elements 2 and another electronic component, that is, an odd-shaped electronic component.
The terminals of the odd-shaped electronic components 17a and 17b are connected to the terminals 16a and 16b inserted together with the relay terminal 5d in the insulating frame 10a. The terminals 16a and 16b are integrated with the frame flange portion 18 protruding from the insulating frame 10a. It is connected to. The plate portion 102 is fixed to the insulating frame 10a from the lower side of the insulating frame 10a, and the lead terminal group 4, the plate terminal portion 8, and the relay terminal 5d are joined by the method described in the first embodiment. Thereafter, odd-shaped electronic components 17a and 17b such as capacitors and coils are mounted to join the terminals and the terminals 16a and 16b.
Joining may be performed by soldering, but since the heat capacity of a terminal for passing a large current is large, a method capable of joining with high energy such as TIG welding or laser welding is preferable. The control board 7 is disposed above the odd-shaped electronic components 17a and 17b, and the relay terminal 5d is soldered.

In the third embodiment, the odd-shaped electronic components are connected in a conductive and heat transfer manner via terminals. The terminal is inserted integrally with the frame flange portion 18 and is connected to the plate 1 which is a heat radiating member via the terminal, so that the heat of the odd-shaped electronic components 17 a and 17 b can be dissipated to the plate 1. The structure of the insulating frame 10a is simplified by attaching sub-parts manufactured by, for example, housing them in an insert case in a configuration in which the odd-shaped electronic components 17a and 17b are combined. This leads to lower costs. Further, since the flange portion 9a for connecting the plates 1a can be used for the connection with the frame flange portion 18 coming out from the sub-part containing the odd-shaped electronic components 17a and 17b, the wiring member is reduced and the complicated wiring is not required. In addition, the device becomes compact and can contribute to the reduction in size and cost.
Moreover, since the thermal resistance from the odd-shaped electronic component to the plate can be reduced, excellent cooling performance can be obtained.

Embodiment 4 FIG.
FIG. 10 is a cross-sectional view schematically showing a circuit device for explaining the fourth embodiment.
The heat dissipating part 6 extending below the semiconductor element of the plate 1 a is covered with a protective cover 19. An air passage 20 is provided between the protective cover 19 and the plate 1a so that the cooling air flows in the cross-sectional direction of FIG. 10, and the gap between the protective cover 19 and the plate 1a is a movement of a fan (not shown). Optimized to match the characteristics. Moreover, it is manufactured with an appropriate gap even in the case of convection by natural air cooling. Further, by sealing between the protective cover 19 and the storage case part, waterproofness can be easily ensured.
According to the fourth embodiment, since the air passage 20 is formed by the protective cover 19, there is no refrigerant bypass, and the cooling performance is further improved. In particular, if the air passage 20 is manufactured integrally with the insulating frame portion 10a of the circuit device, the number of parts does not increase.
In addition, the protective cover 19 serves as both insulation between the air passage 20 and the outside, and there is no need for individual assembly and processing. In particular, in the plate 1a having a surface treated with an insulating layer, it is conceivable that the insulating property is lowered due to the introduction of scratches on the surface. It can be secured. Further, as in the fourth embodiment, since the structure is divided for each plate, there is no electric corrosion between plates of different potentials even when condensation occurs, and the corrosion of the plate due to the occurrence of condensation, etc. Short circuit due to adhesion of foreign matter can be reliably prevented.

Embodiment 5 FIG.
In the first to fourth embodiments so far, the description has been made based on the semiconductor element 2 having the mold package structure. However, as in the fifth embodiment shown in FIG. 11, the bare device 21 is a component corresponding to the semiconductor element 2. Can also be implemented by mounting them on the plates 1a and 1b and assembling them.
In this case, the wiring circuit member 22 is attached to each of the plates 1a and 1b for connection between the bare device 21 and the adjacent plate 1b or the relay terminal 5d to the control board 7.
The wiring circuit member 22 is bent and fixed on the main surface 3a of the plate by bonding or the like, and the main circuit and signal electrodes on the upper surface of the bare device 21 through which the main current flows and the wiring circuit member 22 The bonding wire 23 is used for wire bonding, and the relay terminal 5d and the adjacent plate 1b are connected by a method such as soldering, welding, or conductive resin bonding. The wiring circuit member 22 may be manufactured by connecting a plurality of terminal members by resin molding.

According to the fifth embodiment, since the bare device 21 is directly mounted on the plate 1a, the space around the bare device 21 is smaller than that of the semiconductor element 2 having a mold structure, and the plate portion 102 is downsized. Can do. In particular, the distance between each plate can be reduced.
Moreover, you may join a lead member to the bare device 21 by methods, such as soldering. In this case, for example, by manufacturing a plurality of terminal members connected by resin molding, the positioning accuracy between the terminal materials is good, and assembly is easy.

It is sectional drawing which showed typically the circuit device in Embodiment 1 of this invention. It is sectional drawing which showed typically the modification of the circuit device in Embodiment 1 of this invention. It is a perspective view for demonstrating a plate part. It is the perspective view which showed the plate part concretely. It is the schematic diagram which looked at the power part for demonstrating the circuit apparatus which connects a some plate part in series from the upper surface. It is a perspective view for demonstrating the attachment structure of an insulation frame and a plate part. It is a schematic diagram for demonstrating the method of laser welding a lead terminal group, a terminal part, and a relay terminal. It is sectional drawing which showed typically the circuit device in Embodiment 2 of this invention. It is sectional drawing which showed typically the circuit device in Embodiment 3 of this invention. It is sectional drawing which showed typically the circuit device in Embodiment 4 of this invention. It is sectional drawing which showed typically the circuit device in Embodiment 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a-1L Conductive and heat dissipation plate 101,102,103,111 Plate part 2,2a-2L Semiconductor element 201 Electrode part 3 Conductive part 3a Main surface of a conductive part (mounting surface of semiconductor element 2)
4 Lead terminal group 4a Main current lead terminal 4b Signal terminal 5, 5a, 5b, 5c, 5d Relay terminal 6, 6b Heat radiation part (heat radiation part)
7 Control board 8 Plate terminal part 9, 9a, 9b Flange part 10a Insulating frame part 10b Lid part 10c Bottom plate part 11 Insulating frame part opening part 13a, 13b Beam exit port 14a, 14b Laser 15 Welding part 16a, 16b Terminal 17a 17b odd-shaped electronic component 18 frame flange portion 19 protective cover 20 air passage 21 bare device 22 wiring circuit member 23 bonding wire 24 fin portion.

Claims (4)

Semiconductor element having lead terminal derived from inside of main body and exposed electrode, conductive / heat radiating plate having heat radiating part cooled by exposure to coolant and conductive part on which electrode of said semiconductor element is mounted, said semiconductor An insulating frame for holding a plurality of conductive and heat radiating plates on which elements are mounted at predetermined intervals, and a lead circuit and a connection terminal of the electrode formed on the conductive portion are connected to each other to form a predetermined circuit. A circuit part to be formed,
A plurality of the semiconductor elements are mounted on a single conductive / heat dissipating plate and connected in parallel to each other, and the semiconductor elements mounted in parallel on the adjacent conductive / heat dissipating plates are connected to the circuit. Connected in series by
The circuit device , wherein the heat radiating portion of the conductive / heat radiating plate portion is covered with an insulating cover and cooled with a refrigerant . 2. The circuit device according to claim 1 , wherein the conductive and heat radiating plate is formed of a member having the same shape on which a plurality of semiconductor elements can be mounted . 2. The circuit device according to claim 1, wherein the conductive and heat radiating plates adjacent to each other are electrically and thermally conductively connected by flange portions provided on both side edges . 2. The circuit according to claim 1, wherein another electronic component constituting a circuit together with the semiconductor element is disposed on the insulating frame portion and is electrically and thermally conductively connected to the flange portion. apparatus.

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