JP2005150524A - Electronic controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic controller where connection reliability can be secured by relaxing stress at the connection part of a flexible printed wiring board in the electronic controller obtained by connecting a circuit board and a connector by folded-back flexible printed circuit boards. <P>SOLUTION: The circuit board 20 mounting an electronic part is housed inside of a casing 10. Connectors 30a and 30b are fitted to the casing 10, and the circuit board 20 and the connectors 30a and 30b are connected by the folded-back flexible printed circuit boards 40a and 40b. Inside of the casing 10, the circuit board 20 is placed in the state of being slidable on substrate placing parts 14a, 14b, 14c and 14d. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic control device.

  In the electronic control device, a circuit board on which electronic components are mounted is housed in a housing, and the circuit board and a connector are electrically connected, and are connected to an external device (a sensor, an actuator, or the like) through the connector. As shown in FIG. 10, there is a method of using a flexible printed wiring board 102 as one of methods for electrically connecting the connector 101 and the circuit board 100.

  In the case of using the above technique, a structure in which the flexible printed wiring board 102 is bent as shown in FIG. 10 can be considered for downsizing. However, for further downsizing, the flexible printed wiring board 102 is changed to 180 as shown in FIG. When the connector 120 is folded and disposed on the upper side of the circuit board 100, the following problems occur. Connection on the flexible printed wiring board 102 when the connector 120 is fitted to the housing 110 or when the connector 120 is twisted (rotated or moved laterally) due to dimensional tolerances of the housing 110, etc. Stress is applied to the portions 102a and 102b. At this time, when the force indicated by F3 in FIG. 12 is applied, in the worst case, both ends 130a and 130b of the connecting portion of the flexible printed wiring board 102 are highly likely to be disconnected, and this structure having a large miniaturization effect is not realized. It turns out that.

  In order to avoid this, there are methods such as hardening the connecting portions 102a and 102b (see FIG. 11) of the flexible printed wiring board with an adhesive or sandwiching them with clips, but it is obvious that the cost increases.

  The electrical connection between the flexible printed wiring board 102 and the circuit board 100 is best achieved by soldering in view of long-term reliability and cost, and the use of solder that is weak against external stress also establishes this structure. This is one of the factors that are missing. However, considering the long-term reliability and cost as described above, it is necessary to establish this structure using a connection by soldering.

  The present invention has been made under such a background, and its purpose is to relieve stress at the connecting portion of the flexible printed wiring board in the electronic control device in which the circuit board and the connector are connected by the folded flexible printed wiring board. An object of the present invention is to provide an electronic control device that can ensure connection reliability.

  The invention described in claim 1 is characterized in that the circuit board is slidably mounted on the substrate mounting portion inside the housing. This allows the circuit board to move freely when assembled or when the mating connector is fitted. Therefore, it is possible to relax the stress at the connection portion of the flexible printed wiring board and ensure connection reliability.

  According to a second aspect of the present invention, in the electronic control device according to the first aspect, when the circuit board is provided with a through hole and the substrate mounting portion is provided with a protrusion that enters with a clearance inside the through hole, the substrate While enabling positioning, the stress of the connection part of a flexible printed wiring board can be relieved.

As described in claim 3, in the electronic control device according to claim 2, it is practically preferable that the inner diameter of the through hole is larger by 1 to 1.5 mm than the outer diameter of the protrusion.
According to a fourth aspect of the present invention, in the electronic control device according to the first aspect, if a guide member for positioning the circuit board with respect to the outer periphery of the circuit board is provided in the housing, the board can be positioned. At the same time, the stress at the connection portion of the flexible printed wiring board can be relaxed.

As described in claim 5, in the electronic control device according to claim 4, it is practically preferable that the clearance between the outer peripheral edge of the circuit board and the guide member is 0.5 mm or more.
The electronic control device according to any one of claims 1 to 5, wherein the leg portion that supports the connector in the housing is erected outward from the outer peripheral edge of the circuit board. Then, even when it has a leg part for receiving the insertion / extraction force of the mating connector, the stress of the connection part of the flexible printed wiring board can be relieved without hindering the movement of the circuit board against the displacement of the connector at the time of mating connector insertion / extraction .

  As described in claim 7, in the electronic control device according to any one of claims 1 to 6, the circuit board is placed on the board mounting portion side in the housing by the elastic force of the folded flexible printed wiring board. When a pressing force is applied, the circuit board moves even after assembly while ensuring vibration resistance and impact resistance, and the stress at the connection portion of the flexible printed wiring board can be relieved.

  The electronic control device according to any one of claims 1 to 7, wherein a member having viscosity is interposed between the housing and the circuit board inside the housing, and the member is provided. When a force is applied to maintain the state where the circuit board is in contact with the board mounting portion due to the viscosity of the circuit board, the circuit board moves even after assembly while securing vibration resistance and impact resistance, and the stress at the connection part of the flexible printed wiring board can be relieved.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
The present embodiment is embodied in an in-vehicle electronic control device. FIG. 1 is an exploded perspective view of the electronic control device 1. A housing 10 of the electronic control device 1 has a box shape and includes a lower case 11 and an upper case 12. A circuit board 20 is accommodated in the housing 10. Electronic components 21 are mounted (mounted) on both upper and lower surfaces of the circuit board 20. Connector housings 13a and 13b are integrally formed on the upper surface of the upper case 12 on the left and right. The connectors 30a and 30b are fitted from the lower surface side of the upper case 12 to the portions of the upper case 12 where the connector housings 13a and 13b are provided. The connectors 30a and 30b have a large number of connector pins (connector terminals) 31, and the connector pins 31 protrude into the connector housings 13a and 13b when they are fitted to the upper case 12 (connector housings 13a and 13b). .

  Inside the housing 10, the connectors 30a, 30b and the circuit board 20 are electrically connected by folded flexible printed wiring boards 40a, 40b, that is, flexible printed wiring boards 40a, 40b folded 180 °. More specifically, one end of the flexible printed wiring boards 40a and 40b is soldered to the upper surface of the circuit board 20, and the other end of the flexible printed wiring boards 40a and 40b is soldered to the lower surfaces of the connectors 30a and 30b. In FIG. 1, connecting portions between the flexible printed wiring boards 40a and 40b and the circuit board 20 are denoted by reference numerals 41a and 41b, and connecting portions between the flexible printed wiring boards 40a and 40b and the connectors 30a and 30b are denoted by reference numerals 42a and 42b. .

  In this way, the connectors 30a and 30b are arranged on the upper side of the circuit board 20 by bending the flexible printed wiring boards 40a and 40b by 180 °, and mated with the upper case 12 (connector housings 13a and 13b). Connection with the connectors 45a and 45b is possible. That is, the connectors 30a and 30b are connected to the end of a wire (not shown) via the mating connectors 45a and 45b, and a battery, various sensors, and an engine control actuator are connected to the wires. The electronic control unit 1 detects the operating state of the engine based on the sensor signal, executes various calculations, and drives an actuator such as an injector or an igniter to operate the engine in an optimal state.

  Here, the flexible printed wiring boards 40a and 40b are made as short as possible to reduce the cost. In addition, since the connectors 30a and 30b and the upper case 12 (connector housings 13a and 13b) are fitted to each other because the positional accuracy of the mating connectors 45a and 45b and the connector pins 31 is required, there is no large backlash.

FIG. 2 is a plan view with the upper case 12 removed.
In FIG. 2, substrate mounting portions 14 a, 14 b, 14 c and 14 d are formed integrally with the lower case 11 at the four corners of the lower case 11. The circuit board 20 is placed on the board placement portions 14a, 14b, 14c, and 14d. Further, the circuit board 20 is placed inside the housing 10 in a slidable state on the board placement portions 14a, 14b, 14c, and 14d. Specifically, the circuit board 20 is separated from the inner wall surface of the lower case 11 by a distance d in FIG. 2, and is slidably mounted with a predetermined clearance (backlash). The distance d, that is, the clearance (backlash) is 1 to 1.5 mm.

  As shown in FIG. 3, the flexible printed wiring boards 40a and 40b have a torsional movement (force F1) of the connectors 30a and 30b and a rectangular connector 30a, Absorbs movement (force F2) in a direction parallel to the short side of 30b. Thereby, a large stress is not given to connection part 41a, 41b, 42a, 42b (refer FIG. 1) in flexible printed wiring board 40a, 40b. However, the long sides of the rectangular connectors 30a, 30b as in this structure are long (the lengths of the connecting portions 41a, 41b, 42a, 42b are long), and between the connecting portions 41a-42a (between the connecting portions 41b-42b). When the flexible printed wiring boards 40a and 40b having a short length are used as follows. When a longitudinal force F3 as shown in FIG. 4 that cannot be absorbed by the flexible printed wiring boards 40a and 40b itself is applied, the connection portions of the flexible printed wiring boards 40a and 40b (reference numerals 41a, 41b, FIG. 42a, 42b) tries to give excessive stress. In particular, an excessive stress is applied to both end portions 43a and 43b of the connection portions 41a, 41b, 42a and 42b.

  In the present embodiment, no stress is applied to the connection portions 41a, 41b, 42a, and 42b in the flexible printed wiring boards 40a and 40b even with the force F3 in the longitudinal direction. That is, as shown in FIG. 5, when the mating connectors 45a and 45b are fitted together, the connection portions 41a and 41b of the flexible printed wiring board are subject to the longitudinal movement (force F3) of the connectors 30a and 30b. , 42a, 42b, the circuit board 20 can freely move in a direction to relieve the stress. As a result, the circuit board 20 rotates and does not apply stress to the connection portions 41a, 41b, 42a, and 42b, and relaxes the stress of the connection portions 41a, 41b, 42a, and 42b of the flexible printed wiring board, thereby improving connection reliability. It can be secured.

  In this way, in the electronic control unit 1 in which the circuit board and the connector are connected by the folded flexible printed wiring boards 40a and 40b, the connection of the flexible printed wiring boards 41a, 41b, 42a and 42b is relaxed and connected. Reliability can be ensured. In addition, the connecting portion (soldering portion) 41a, 41b, 42a, 42b of the flexible printed wiring board is not costly because a reinforcing member such as an adhesive or a clip is not required.

  As described above, when the connectors 30a, 30b and the circuit board 20 are connected by the flexible printed wiring boards 40a, 40b, the connecting portions 41a, 41b, 42a of the flexible printed wiring board when the connectors 30a, 30b are twisted. , 42b, the circuit board 20 moves so as to relieve the stress. Thereby, a miniaturized structure in which the connectors 30a and 30b are bent on the circuit board 20 using the flexible printed wiring boards 40a and 40b can be realized.

In addition, you may change the said embodiment as follows.
In consideration of the manufacturing process such as assemblability, as shown in FIG. 6, as shown in FIG. A through hole 50 having a diameter larger than the diameter of the protrusion 51 is formed in the circuit board 20. Then, the protrusion 51 is inserted into the through hole 50.

  In this case, from the fitting accuracy of the connectors 30a, 30b and the upper case 12 (connector housings 13a, 13b), in order to relieve the stress of the connecting portions 41a, 41b, 42a, 42b in the flexible printed wiring boards 40a, 40b, For example, the inner diameter of the through hole 50 may be larger by 1 to 1.5 mm or more than the outer diameter of the protrusion 51. In addition, this protrusion 51 may not be a cylindrical shape but may be a quadrangular column or the like, and the through hole 50 is also the same.

  Thus, by providing the through holes 50 in the circuit board 20 and providing the protrusions 51 that enter the substrate mounting portions 14a, 14b, 14c, and 14d with clearance (backlash) inside the through holes 50, the substrate positioning is performed. And the stress of the connecting portions 41a, 41b, 42a, 42b of the flexible printed wiring board can be relieved. Further, it is practically preferable that the inner diameter of the through hole 50 is 1 to 1.5 mm larger than the outer diameter of the protrusion 51.

  As shown in FIG. 7, when positioning with respect to the outer shape of the circuit board 20, a guide member for positioning the circuit board 20 with respect to the outer peripheral edge of the circuit board 20 inside the housing 10 (with respect to the outer shape of the board). A guide member 60 for positioning is provided. As a result, the board can be positioned and the connection parts 41a, 41b, and 42a of the flexible printed wiring board are not hindered by the movement of the circuit board 20 with respect to the displacement of the connectors 30a and 30b when the mating connectors 45a and 45b are inserted and removed. , 42b can be relieved. In particular, the clearance (backlash) between the outer peripheral edge of the circuit board 20 and the guide member 60 is 0.5 mm or more, which is practically preferable.

  Further, as shown in FIG. 8, the leg portions 70 that support the connectors 30 a and 30 b in the housing 10 may be erected outward from the outer peripheral edge of the circuit board 20. In other words, the circuit board 20 has a structure in which the leg portions (supports) 70 of the connectors 30a and 30b for receiving the insertion / extraction force of the mating connectors 45a and 45b are erected on the lower case 11 outside the outer peripheral edge of the circuit board 20. So as not to interfere with the movement of Therefore, when the mating connectors 45a and 45b are inserted after assembly, and when the mating connectors 45a and 45b are twisted, the circuit board 20 moves and stress is applied to the connecting portions 41a, 41b, 42a and 42b of the flexible printed wiring board. Absent. In this way, even when the leg portion (support) 70 for receiving the insertion / extraction force of the mating connectors 45a and 45b is provided, the movement of the circuit board 20 with respect to the displacement of the connectors 30a and 30b during mating connector insertion / extraction. The stress at the connecting portions of the flexible printed wiring boards 40a and 40b can be relaxed without hindering.

  At this time, as shown in FIG. 9, the circuit board 20 is placed in the housing 10 by the elastic force (force F10 in FIG. 9) by the folded flexible printed wiring boards 40a and 40b. A pressing force is applied to the 14d side. That is, in order to restrain vibration and shock resistance, the circuit board 20 is pressed using the elasticity of the flexible printed wiring boards 40a and 40b in order to restrain the vertical movement of the circuit board 20. As a result, the circuit board 20 moves even after assembling while ensuring vibration resistance and impact resistance, and the stress of the connecting portions 41a, 41b, 42a, and 42b of the flexible printed wiring board can be relaxed. The material of the flexible printed wiring boards 40a and 40b is optimally polyimide that has an appropriate elasticity to hold the circuit board 20 and does not apply stress to the connecting portions 41a, 41b, 42a, and 42b of the flexible printed wiring board.

  Furthermore, a viscous member 81 is interposed between the lower case 11 of the housing 10 and the circuit board 20 inside the housing 10, and the circuit board 20 is mounted on the substrate mounting portions 14 a, 14 b, 14 c by the viscosity of the member 81. , 14d is applied to maintain the state of contact. That is, the circuit board 20 is brought into close contact with the board mounting portions 14a, 14b, 14c, and 14d (lower case 11 side) by the viscosity of the member 81. Specifically, as the viscous member 81, a heat radiating gel or grease for radiating heat of the heat generating element 80 is used. In this way, by providing the viscous member 81, the circuit board 20 moves even after assembly while securing vibration resistance and impact resistance, and the stress of the connection portions 41a, 41b, 42a, 42b of the flexible printed wiring board is relieved. it can. The viscous member (heat dissipating gel or grease) 81 may have a thickness of about 0.5 mm, for example.

The disassembled perspective view of the electronic control unit in an embodiment. The top view of an electronic controller. The perspective view which shows the motion of a connector. The perspective view which shows the motion of a connector. The top view which shows the motion of a connector. The perspective view of the electronic controller of another example. The perspective view of the electronic controller of another example. (A) is a perspective view of another example of an electronic control device, (b) is a longitudinal sectional view of another example of an electronic control device. The longitudinal cross-sectional view of the electronic control apparatus of another example. The side view of the electronic controller for demonstrating background art. The longitudinal cross-sectional view of the electronic controller for demonstrating background art. The perspective view which shows the motion of a connector.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Housing | casing, 14a, 14b, 14c, 14d ... Board | substrate mounting part, 20 ... Circuit board, 21 ... Electronic component, 30a, 30b ... Connector, 40a, 40b ... Flexible printed wiring board, 41a, 41b, 42a, 42b ... Connection part, 50 ... Through hole, 51 ... Projection, 60 ... Guide member, 70 ... Leg part, 81 ... Member having viscosity.

Claims (8)

The circuit board (20) on which the electronic component (21) is mounted is housed in the housing (10), and the connectors (30a, 30b) are fitted into the housing (10), so that the housing (10) An electronic control device in which a circuit board (20) and connectors (30a, 30b) are connected by folded flexible printed wiring boards (40a, 40b),
An electronic control device, wherein the circuit board (20) is slidably mounted on a substrate mounting portion (14a, 14b, 14c, 14d) inside the housing (10). The electronic control device according to claim 1.
A through hole (50) is provided in the circuit board (20), and a protrusion (51) is provided in the board mounting part (14a, 14b, 14c, 14d) with a clearance inside the through hole (50). An electronic control device characterized by that. The electronic control device according to claim 2,
The electronic control device according to claim 1, wherein an inner diameter of the through hole (50) is larger by 1 to 1.5 mm than an outer diameter of the protrusion (51). The electronic control device according to claim 1.
An electronic control device comprising a guide member (60) for positioning the circuit board (20) with respect to an outer peripheral edge of the circuit board (20) inside the housing (10). The electronic control device according to claim 4.
The electronic control device according to claim 1, wherein a clearance between the outer peripheral edge of the circuit board (20) and the guide member (60) is 0.5 mm or more. The electronic control device according to any one of claims 1 to 5,
An electronic control device characterized in that legs (70) supporting the connectors (30a, 30b) are erected outward from the outer peripheral edge of the circuit board (20) in the housing (10). . The electronic control device according to any one of claims 1 to 6,
Applying a force to push the circuit board (20) toward the board placement part (14a, 14b, 14c, 14d) in the housing (10) by the elastic force of the folded flexible printed wiring boards (40a, 40b). An electronic control device. The electronic control device according to any one of claims 1 to 7,
A viscous member (81) is interposed between the casing (10) and the circuit board (20) inside the casing (10), and the circuit board (20) is mounted on the board by the viscosity of the member (81). An electronic control device characterized in that a force is applied to maintain a state in contact with the mounting portions (14a, 14b, 14c, 14d).

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