JP2001223489A - Electronic control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent interference between an internal circuit and an external circuit due to noise signal through a connector fitted to a shield case. SOLUTION: An electronic control device 1 for a vehicle is provided wherein a circuit board unit 2 where an electronic circuit part 22 is assembled is housed in a shield case, and the electronic circuit part 22 is electrically connected to an external circuit using connectors C1 and C2. Here, a shield material 5 for shielding, in electromagnetic manner, the connectors C1 and C2 from the electronic circuit part 22 is provided on the circuit board unit 2, with the shield material 5 fitted with driving semiconductor elements T1-T12 for releasing heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic control unit for a vehicle used for electronically controlling devices for a vehicle such as an internal combustion engine for a vehicle and an air conditioner for a vehicle.

[0002]

2. Description of the Related Art In order to electronically control various vehicle devices mounted on a vehicle, such as a vehicle internal combustion engine and a vehicle air conditioner, required electronic circuits and drive transistors are mounted in a metal housing. The electronic control unit for a vehicle that is housed and unitized is set in the vehicle interior or the engine room, and the internal circuit is electrically connected to the required controlled device and the like by a wire harness using the connection connector provided on the housing side. Is generally adopted.

[0003] By the way, this kind of vehicle electronic control device often uses a microcomputer system. Therefore, an oscillation circuit for generating a clock of a digital element such as a CPU or a gate array is provided by the vehicle electronic control device. Is built in. For this reason, an extremely high-level noise signal is generated around a digital circuit section including a digital element and an oscillation circuit, and a high-current driving semiconductor element or a high-speed switching semiconductor that operates in response to an output signal from the digital circuit section. An extremely strong pulse noise signal is generated around the element.

On the other hand, the wiring terminals of the connector for making necessary electrical connection between the circuit board and the outside are exposed in the housing, so that the above-mentioned various noise signals generated in the circuit are connected. It is released to the outside via the wiring terminals of the connector, which invades another electronic control unit for a vehicle and causes a malfunction, and also impairs the operation of the receiving device and the direction detector.

In order to avoid such a problem, in a conventional electronic control unit for a vehicle, a driving semiconductor element, which is a source of a particularly strong noise signal, is arranged near the connector to be connected to the connector. In addition, the wiring distance between them is shortened, and a digital circuit including an oscillating circuit is arranged as far as possible from an analog circuit.

[0006]

By the way, the driving semiconductor element usually needs to be attached to the side surface of the metal frame of the housing for heat radiation. Therefore, when the number of the driving semiconductor elements increases, the driving semiconductor element is not always required. It cannot be arranged near the connector, and the wiring distance between the driving semiconductor element and the connector becomes longer, so that there is a problem that a noise signal is easily picked up on the connector side. Further, even if an oscillation circuit and a peripheral digital circuit which are noise sources are arranged at a distance from the connector, there is a limit in reducing the adverse effect, and it cannot be a sufficient noise countermeasure.

An object of the present invention is to provide an electronic control unit for a vehicle which can solve the above-mentioned problems in the prior art.

[0008]

According to the present invention, there is provided, in accordance with the present invention, a circuit board unit in which an electronic circuit section for controlling a vehicle device including a driving semiconductor element is assembled. An electronic control unit for a vehicle, wherein the electronic control unit is housed in a shield case, and electrical connection between the electronic circuit unit and an external circuit is performed via a connector electrically connected to the circuit board unit. A shield material for electromagnetically shielding the connector from the electronic circuit unit is provided on the circuit board unit,
An electronic control unit for a vehicle is proposed in which the driving semiconductor element is attached to the shield member for heat radiation.

Due to the electromagnetic shielding effect between the electronic circuit section and the connector by the shield material, the level of a noise signal induced in the connector by a noise signal generated in the electronic circuit section can be reduced. The level of the noise signal emitted out of the case can be reduced. In addition, since heat generated from the driving semiconductor element can be radiated near the connector by the shield material, a large number of driving semiconductor elements requiring heat radiation are arranged near the connector, and the driving semiconductor element and the connector are connected to each other. Can be configured so as to shorten the arrangement between them.

[0010] It is preferable that the shielding material be disposed as close to the connector as possible. The shape of the shield material may be a conductive plate material having an appropriate thickness, and this plate material may be a U-shape surrounding the electronic circuit portion, but may be a linear plate material. Further, this plate member can be formed in a square shape surrounding the electronic circuit portion.

[0011] The shield material to be used as a heat sink may be made of a conductive material, and the resist may be peeled off from the contact portion of the circuit board so that the shield material contacts the ground copper foil of the board. As a result, the potential gradient of the ground is reduced, and the ground effect can be increased. In order to enhance the heat radiation performance as a heat radiating plate, the material of the shielding material may be an appropriate material having good thermal conductivity and electromagnetic shielding performance, for example, aluminum.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an exploded perspective view showing an example of an embodiment of a vehicle electronic control device according to the present invention. The electronic control unit 1 for a vehicle shown in FIG. 1 constitutes an electronic control unit for electronically controlling fuel injection into an internal combustion engine (not shown), and controls each part of the fuel injection device (not shown) electronically. A circuit board unit 2 in which an electronic circuit for performing the operation is assembled, and a casing 3 made of aluminum die-cast for accommodating the circuit board unit 2 are provided.

In this embodiment, the circuit board unit 2 has necessary electronic components mounted on a single printed wiring board 21, thereby forming an electronic circuit section 22. Connectors C1 and C2 for electrically connecting the electronic circuit unit 22 to an external circuit are aligned and attached to a bracket 23 fixed to one end of the printed wiring board 21, and each of the connectors C1 and C2 is connected. The pin groups P1 and P2 are exposed on the printed wiring board and are soldered to the printed wiring board 21.

In order to electromagnetically shield the entire circuit board unit 2 assembled as described above, the circuit board unit 2 is housed in a frame 3 and the frame 3 is made of a conductive metal material such as iron or aluminum. The lid member 4 is screwed. As a result, the circuit board unit 2
Is housed and sealed in a shield case composed of a frame 3 and a lid member 4, and the circuit board unit 2 is electromagnetically shielded. Here, in the circuit board unit 2, the connectors C1 and C2 are housed in the frame 3 so as to look out from the opening 3A of the frame 3, and connection members (not shown) corresponding to the connectors C1 and C2 are provided. It is configured to be inserted from the opening 3A for connector connection.

Next, referring to FIG.
Will be described in detail.

In FIG. 2, an electronic circuit portion generally indicated by reference numeral 22 is composed of driving semiconductor elements T 1 to T 12 requiring heat radiation and other transistors assembled on the printed wiring board 21. , Resistors, capacitors,
An electronic circuit unit 22 required for electronic control of fuel injection is constituted by the circuit element group 24 such as various IC elements, and the circuit element group 24 and the driving semiconductor elements T1 to T12. Note that the configuration of the electronic circuit unit 22 shown in the present embodiment is an example, and in general, an electronic circuit unit configured as an appropriate electronic circuit device including at least one driving semiconductor element is mounted on the printed wiring board 21. Mounted on

The circuit element group 24 includes a digital circuit section 24 including a CPU and a gate array connected thereto.
A and an analog circuit section 21B for analog signal processing.

A noise signal generated from the electronic circuit section 22 mounted on the printed wiring board 21 is transmitted to the electronic control unit 1 for the vehicle through the respective connection pin groups P1 and P2 exposed from the main bodies of the connectors C1 and C2. The shield member 5 made of a conductive metal material is provided on the printed wiring board 21 in order to prevent the radiation to the outside.

In the present embodiment, the shield member 5 is formed by bending an elongated aluminum plate member having an appropriate thickness into a U-shape, and the shield member 5 is provided integrally with a lower end edge thereof. It is firmly screwed and fixed on the printed wiring board 21 using the legs 51 to 57. The middle side 5A of the shield member 5 extends substantially in parallel with the connectors C1 and C2 in the vicinity of the connectors C1 and C2, and the pair of parallel sides 5B and 5C of the shield member 5 correspond to the ends of the printed wiring board 21. It is arranged so as to extend parallel to and close to the edges 21A, 21B.

As a result, the electronic circuit section 22 is
, The electronic circuit unit 22 and the connectors C1, C
An electromagnetic shield between the two is established. Further, the U-shaped shield member 5 is connected to the printed wiring board 21.
The printed wiring board 21 is mounted on the printed wiring board 21 as described above.
Because the mechanical strength of the vehicle is improved, its seismic resistance is remarkably improved, the durability against vibration from the vehicle is increased, and the reliability of the device is greatly improved.

In order to use the shield member 5 provided as described above also as a heat sink, the driving semiconductor elements T1 to T1
Numeral 2 is disposed on the printed wiring board 21 along the inner side surface 5a of the shield member 5, and is attached to the shield member 5 so as to be pressed against the inner side surface 5a.

FIG. 3 is a sectional view showing a state in which the driving semiconductor element T1 is attached to the shield member 5. The driving semiconductor element T1 is mounted on the printed wiring board 21 such that the heat radiation surface T1A is slightly away from the inner surface 5a of the shield member 5 and faces the same.
An insulating film F1 made of a material having good heat transfer coefficient and electrical insulation between the heat radiation surface T1A and the inner side surface 5a.
Is provided. Then, the clip member CP is held in a state where the cushioning material B1 is applied to the front surface T1B of the driving semiconductor element T1.
3, the driving semiconductor element T1 is pressed toward the shield member 5 via the cushioning material B1 by the spring holding portion CP1a of the clip member CP1. The shield member 5 is electrically connected to the ground pattern PA exposed by stripping the resist, so that the potential gradient of the ground is reduced and the effect of the ground is increased.

In the above, the mounting structure for radiating the driving semiconductor element T1 to the shield member 5 has been described.
As can be seen from FIG. 2, the driving semiconductor elements T2 and T3 also
Together with the driving semiconductor element T1, the clip member CP1 is pressed against the shield member 5 for heat radiation. The other driving semiconductor elements T4 to T12 are also pressed against the inner surface 5a of the shield member 5 for heat radiation using other clip members CP2 to CP6 in the same manner (see FIG. 2).

The driving semiconductor elements T1 to T12 are satisfactorily dissipated through the shield member 5 by being pressed against the shield member 5 as described above.
1 to T12 are connectors C1, C2 by the shield material 5.
And are electromagnetically shielded, and the driving semiconductor elements T1 to T1
2, the connection pin groups P1 and P
2, the level at which the noise signal induced outside is emitted to the outside via the connectors C1 and C2 can be significantly reduced as compared with the related art. Also, since the middle side 5A of the shield member 5 is disposed near the connectors C1 and C2, the connector C
A large number of driving semiconductor elements connected to C1 and C2 can be arranged near connectors C1 and C2, and the wiring distance between these driving semiconductor elements and connectors C1 and C2 can be shortened. It is possible to reduce noise signal leakage from the wiring portion.

The shielding material 5 is provided on the printed wiring board 21.
When the printed wiring board 21 is arranged and fixed in this manner, the mechanical strength of the printed wiring board 21 is reinforced, and even when the printed wiring board 21 is a single large plate material, it is resistant to vibrations received when mounted on a vehicle. And the reliability of the device can be increased.

In the above-described embodiment, as shown in FIG. 2, the shape of the shield member 5 is U-shaped, but the shape of the shield member 5 is not limited to this. Any other shape may be used as long as an electromagnetic shielding effect between the connector and the connectors C1 and C2 can be obtained and the semiconductor device for driving included in the electronic circuit section 22 can be used for heat radiation. Therefore, in FIG.
The free ends 5Ba and 5Ca of the parallel sides 5B and 5C may be connected using an aluminum plate or the like as shown by a two-dot chain line to form the shield member 5 in a square shape. With the square shape, the electromagnetic shielding effect between the electronic circuit unit 22 and the connectors C1 and C2 can be further increased.

FIG. 4 shows a main part of another embodiment of the present invention. Circuit board unit 102 shown in FIG.
Can be used in place of the circuit board unit 2 shown in FIG. 1, and a plate-shaped shield member 105 made of aluminum is provided on the printed wiring board 121 of the circuit board unit 102. 4 that are the same as those in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted.

The shield member 105 is disposed in the vicinity of the connectors C1 and C2 along the direction in which the connectors C1 and C2 are arranged, and the mounting legs 151, 152 and 153 provided integrally with the shield member 105 are connected to the printed wiring board 121. Screw 105 to the printed wiring board 1
21.

In the embodiment shown in FIG. 4, two driving semiconductor elements T101 and T102 that need to be radiated by the shield member 105 are connected to the clip members CP101 and CP101.
2 is pressed against the shield member 105 by the same configuration as shown in FIG. The electronic circuit section 122 is configured by the driving semiconductor elements T101 and T102 and the circuit element group 124.

According to this configuration, the electronic circuit section 122 and the connectors C1 and C2 can be electromagnetically shielded by the shield member 105, and the driving semiconductor elements T101 and T102 can be connected to the connector C by the shield member 105.
1, they can be effectively dissipated while being arranged in the vicinity of C2. Therefore, if the number of driving semiconductor elements requiring heat radiation is relatively small, the shielding material 10
The shape of 5 is small and convenient.

In any of the embodiments shown in FIG. 2 and FIG.
05 is preferably disposed as close to the connectors C1 and C2 as possible.

[0033]

According to the present invention, since the connector is electromagnetically shielded from the electronic circuit by the shield material, the noise signal level induced in the connector by the noise signal generated in the electronic circuit can be reduced. Therefore, the level of a noise signal emitted outside the shield case via the connector can be reduced, and the influence on peripheral devices can be reduced. Conversely, due to the electromagnetic shielding effect between the electronic circuit part and the connector by the shielding material, even if an external noise signal enters the shield case via the connector, the electronic circuit will have a greater effect on the noise signal. Can be avoided.

Further, since heat generated from the driving semiconductor element can be radiated near the connector by the shield material, a large number of driving semiconductor elements requiring heat radiation are arranged near the connector, and The wiring between the connector and the connector can be shortened, which helps to suppress the generation of a noise signal in the shield case.

Further, by providing the shielding material on the circuit board unit, the mechanical strength of the circuit board unit can be improved, so that the earthquake resistance of the device is increased.
For this reason, even if a vibration due to running of the vehicle or the like is applied, it is possible to effectively prevent the circuit board unit from being mechanically damaged by this, and it is possible to expect a remarkable improvement in the reliability of the device. .

Further, by connecting the shield material to the ground on the circuit board unit, the ground potential gradient on the circuit board can be reduced, and the ground effect can be increased.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an example of an embodiment of a vehicle electronic control device according to the present invention.

FIG. 2 is an enlarged plan view of the circuit board unit shown in FIG.

FIG. 3 is a cross-sectional view showing a configuration in which a driving semiconductor element is mounted on a shield material.

FIG. 4 is a plan view showing another embodiment of the circuit board unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle electronic control apparatus 2 Circuit board unit 3 Frame 4 Cover member 5 Shielding material 21 Printed wiring board 22 Electronic circuit part C1, C2 connector CP1-CP6 Clip member P1, P2 Connection pin T1-T12 Large current drive semiconductor element

Claims (5)

[Claims] 1. A circuit board unit in which an electronic circuit unit for controlling a vehicle device including a driving semiconductor element is assembled and housed in a shield case, and between the electronic circuit unit and an external circuit. An electronic control unit for a vehicle, wherein the electrical connection of the electronic circuit unit is performed via a connector electrically connected to the circuit board unit, and a shield for electromagnetically shielding the connector from the electronic circuit unit. An electronic control device for a vehicle, wherein a material is provided on the circuit board unit, and the driving semiconductor element is attached to the shield material for heat radiation. 2. The electronic control unit for a vehicle according to claim 1, wherein the shield member is a plate-like member made of aluminum. 3. The shield material is formed in a U-shape, the electronic circuit portion is arranged inside the shield material, and the connector is arranged outside the shield material. Electronic control unit for vehicles. 4. The electronic control unit for a vehicle according to claim 2, wherein said driving semiconductor element is mounted so as to be pressed against said shield member. 5. The electronic control unit for a vehicle according to claim 4, wherein the driving semiconductor element is pressed against the shield member by a clip member.