JP4673211B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device suitable for a vehicle or the like provided with a power module and a control circuit board, and more particularly, to an apparatus that involves soldering in the electrical connection between the power module and the control circuit board.

  A power conversion device used for a vehicle or the like usually includes a power module and a control circuit board, and it is necessary to solder the terminal portion (gate terminal, pin head, etc.) to electrically connect them. It is.

  However, during operation of the power converter, the power module and the control circuit board are heated and heated, and this temperature rise causes the power module and the control circuit board (components thereof) to expand with different thermal expansion coefficients. A tensile load or a compressive load is applied to the soldering part, which is the connection between the module and the control circuit board, to concentrate stress, and this stress concentration tends to cause problems such as peeling, cracking, and deterioration in the soldering part. Become.

  If troubles such as peeling, cracking, and deterioration are likely to occur in the soldered portion in this way, there is a risk of causing a connection failure and thus a malfunction or failure of the device, and the reliability is significantly lowered.

  Therefore, conventionally, in order to increase the reliability of the soldered portion, for example, as described in Patent Document 1 below, a gate terminal (external electrode terminal) for electrically connecting the power module and the control circuit board Has been proposed that has a U-bend shape to provide a spring effect and relieve the stress applied to the soldered portion.

JP-A-5-259334

  However, in a power conversion device used for a vehicle, in addition to heat generation and temperature rise of its component parts, vibration is also propagated from the vehicle (wheel, engine, etc.), so a load (stress) is repeatedly applied to the soldered portion However, in the configuration described in Patent Document 1, countermeasures against vibration are insufficient, and there is a possibility that stress applied to the soldered portion cannot be sufficiently relaxed.

In addition, in a power converter for vehicles, particularly for automobiles, there is a strong demand for downsizing of the device in order to ensure a wide range of habitability. However, the device described in Patent Document 1 is directly above the power module. Since the control circuit board is disposed on the gate module and the gate terminal (external electrode terminal) has a U-bend shape (or S-bend shape), the control circuit board must be disposed far away from the power module. I hate that the space occupied by the device (especially in the height direction) becomes large. In other words, it is necessary to secure a large space above the power module, and it is difficult to reduce the size.

  The present invention has been made to solve the above-described problems. The object of the present invention is to increase the temperature of the heat generation and vibration in the soldering portion for electrically connecting the power module and the control circuit board. It is an object of the present invention to provide a power conversion device that makes it difficult to apply a load (stress) due to the above, can improve reliability, and can reduce the size of the device.

In order to achieve the above object, a power conversion device according to the present invention includes a power module, a control circuit board disposed on a side of the power module to control driving of the power module, the power module, and the control circuit. And a flexible wiring board that is electrically connected by soldering while being loosened between the board and the board.
A terminal member for electrically connecting the control circuit board and the flexible wiring board is disposed through the control circuit board and is electrically connected to a wiring pattern mounted on the control circuit board. Through hole conductors, pedestal portions arranged on the surface of the through hole conductors on the flexible wiring board side, through holes of the through hole conductors and through holes of the pedestal portions, and upper and lower end portions thereof And a pin arranged so as to protrude in the vertical direction.
Further, the flexible wiring board has a pin fitting insertion hole fitted into the pin protruding from the pedestal portion, and has a soldering surface around the upper surface of the pin fitting insertion hole, The soldering surface is soldered and is electrically connected, and the lower end portion of the pin is soldered and electrically connected to the inside of the through hole of the through hole conductor and the lower surface of the through hole. Yes .

Preferably, the flexible wiring board is bent into a “U” shape, a “U” shape, an “S” shape, etc. in a side view so as to have a slack between the power module and the control circuit board. Has been distributed.
In a preferred embodiment, the control circuit board is disposed on the side of the power module.

  The flexible wiring board is preferably a base film made of a synthetic resin such as polyester or polyimide, a wiring section made of a conductor such as copper provided on the base film, and the wiring section on the base film. And a synthetic resin cover film laminated so as to cover the entire surface excluding the soldering surfaces at both ends.

  In the power conversion device according to the present invention configured as described above, the power module and the control circuit board are electrically connected by the flexible wiring board. The stress applied to the soldered portion in the apparatus is absorbed and relaxed by the flexible wiring board. Therefore, defects such as peeling, cracking, and deterioration are less likely to occur in the soldered portion, and reliability can be improved.

  Hereinafter, embodiments of a power conversion device of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a main part of an embodiment of a power conversion device according to the present invention, and FIG. 2 is a partially cutaway plan view of the power conversion device shown in FIG. In addition, in each figure (FIGS. 1-4) used for description of an apparatus, the thickness of a component is drawn exaggerated for convenience.

  The power conversion apparatus 10 according to the present embodiment includes a power module 20 and a control circuit board 30 disposed on an upper side of the power module 20, and is flexible between the power module 20 and the control circuit board 30. The wiring board 40 is distributed in a slack state, and one end side of the wiring portion 45 provided on the flexible wiring board 40 is electrically connected to a gate terminal (gate pin) 25 provided on the power module 20 by soldering. The other end is electrically connected to a terminal member (through-hole conductor 33 and pin head 35) provided on the control circuit board 30 by soldering.

  Hereinafter, the device configuration will be described in detail.

  Although not shown, the power module 20 and the control circuit board 30 are held and fixed at predetermined positions in the apparatus case by a support base (heat radiating plate) and brackets.

  In the power module 20, a gate terminal (gate pin) 25 bent in a crank or key shape is embedded (insert molding) in a synthetic resin main body portion 22, and a distal end portion 25 a of the gate pin 25 is located above the main body portion 22. It projects vertically from the end face 22a.

  For example, three gate pins 25 (the number of which can be arbitrarily set) are arranged in parallel in the front-rear direction, and a plurality of groups composed of this arbitrary number are arranged in parallel in the front-rear direction at a predetermined interval. (Only one set is shown in FIG. 2).

  Although the control circuit board 30 is not shown, a control semiconductor chip or the like is mounted on one side or both sides of the board part 32 and a wiring part (wiring pattern) for connecting them is formed. On one end side (power module 20 side), a through hole (conductor) 33 is provided which is electrically connected to the control semiconductor chip or the like via the wiring pattern.

  As in the case of the gate pin 25, for example, three through-hole conductors 33 (the number can be arbitrarily set) are arranged in parallel in the front-rear direction at predetermined intervals. They are arranged side by side (only one set is shown in FIG. 2).

  A pin 37 of a pin head 35 placed on the board portion 32 is fitted and inserted into the through-hole conductor 33, and the terminal member of the control circuit board 30 is constituted by the through-hole conductor 33 and the pin head 35.

  The pin 37 of the pin head 35 has a lower end portion 37 b projecting downward from the bottom surface of the through-hole conductor 33, and an upper end portion 37 a projecting upward from the top surface of the pedestal portion 36. The hole conductor 33 is soldered to be conducted (soldering portion 53). Note that tin plating is applied to the outer peripheral surfaces of the gate pins 25 and the pins 37 of the pin head 35.

  On the other hand, the flexible wiring board 40 disposed between the power module 20 and the control circuit board 30 has a base film 42 made of synthetic resin such as polyester or polyimide, as shown in FIGS. And a wiring portion 45 made of a conductor such as copper provided on the base film 42 and a laminate so as to cover the entire surface of the base film 42 except for the soldering surfaces (circular) 45a and 45b at both ends of the wiring portion 45. The synthetic resin cover film 46 is formed, and circular openings 46a and 46b are formed in portions corresponding to the soldering surfaces (circular) 45a and 45b at both ends of the wiring portion 45 of the cover film 46, Gate pins 2 are provided on portions of the base film 45 and the wiring portion 45 corresponding to the center portions of the soldering surfaces (circular) 45a and 45b at both ends. And the pin insertion hole 44, 44 is formed of a pin 37 of the pin head 35 is fitted.

  Like the gate pin 25 and the through-hole conductor 33, for example, three wiring portions 45 (the number of which can be arbitrarily set) are arranged in parallel in the front-rear direction at a predetermined interval. Here, for example, a plurality of flexible wiring boards 40 provided with three wiring portions 45 as shown in FIG. 3 are used.

  The flexible wiring board 40 has a reverse “U” shape (see FIG. 1) and an inverted “U” shape (see FIG. 4) so as to have a slack between the power module 20 and the control circuit board 30. ), A terminal terminal (gate pin) 25 provided on the power module 20 with a soldering surface 45a on one end side of the wiring portion 45 provided in the flexible wiring board 40 being bent and arranged in an “S” shape or the like. The other end side soldering surface 45b is soldered to the upper end portion 37a of the pin 37 of the pin head 35 provided on the control circuit board 30 (soldering portion 52). Are electrically connected.

  In the power conversion device 10 of this embodiment having such a configuration, the power module 20 and the control circuit board 30 are electrically connected by the flexible wiring board 40, so that they generate heat and are vibrated. However, the stress applied to the soldered portion in the conventional apparatus is absorbed and relaxed by the flexible wiring board 30. For this reason, defects such as peeling, cracking, and deterioration are unlikely to occur in the soldered portions 51 and 52, and reliability can be improved.

  Further, since the flexible wiring board 40 is used for electrical connection between the power module 20 and the control circuit board 30, it is not necessary to arrange the control circuit board 30 directly above the power module 20. There is no need for a large space above. Therefore, the apparatus can be downsized.

  In the above-described embodiment, for example, a plurality of flexible wiring boards 40 provided with three wiring portions 45 are used for connection between the power module 20 and the control circuit board 30. A single flexible wiring board provided with the required number of portions 45 may be used.

Sectional drawing which shows the principal part of one Embodiment of the power converter device which concerns on this invention. The partial notch top view of the power converter device shown by FIG. The flexible wiring board used for the power converter device shown by FIG. 1 is shown, (A) is a top view, (B) is BB arrow sectional drawing of (A). Sectional drawing which shows the other example of the distribution aspect of the flexible wiring board in the power converter device shown by FIG.

Explanation of symbols

10 Power Converter 20 Power Module 25 Gate Pin (Gate Terminal)
30 Control circuit board 33 Through-hole conductor 35 Pin head 40 Flexible wiring board 45 Wiring part 51, 52, 53 Soldering part

Claims (3)

A power module, a control circuit board that is disposed on a side of the power module and controls driving of the power module, and is electrically connected by soldering with a slack between the power module and the control circuit board. A flexible wiring board to be connected to each other,
A terminal member that electrically connects the control circuit board and the flexible wiring board is disposed through the control circuit board and is electrically connected to a wiring pattern mounted on the control circuit board. A hole conductor, a pedestal portion disposed on the surface of the through-hole conductor on the flexible wiring board side, and a through hole of the through hole conductor and a through hole of the pedestal portion, and the upper and lower ends thereof are vertically oriented And a pin arranged to protrude to
The flexible wiring board has a pin insertion hole fitted into the pin protruding from the pedestal portion, and has a soldering surface around the upper surface of the pin insertion hole, and the upper end portion of the pin and the solder The mounting surface is soldered and electrically connected,
The power conversion device , wherein a lower end portion of the pin is soldered to and electrically connected to the inside of the through hole of the through hole conductor and the lower surface of the through hole .   The flexible wiring board is bent and arranged in a “U” shape, a “U” shape, an “S” shape or the like in a side view so as to have a slack between the power module and the control circuit board. The power converter according to claim 1, wherein the power converter is present.   The flexible wiring board includes a base film made of a synthetic resin such as polyester or polyimide, a wiring portion made of a conductor such as copper provided on the base film, and soldered surfaces on both ends of the wiring portion on the base film. The power conversion device according to claim 1, comprising: a synthetic resin cover film laminated so as to cover the entire surface.

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