JPH0322943Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an electronic circuit unit for an automobile in which a case equipped with an electric circuit, a circuit board, etc. are formed using an enamel substrate.

(Prior Art) With the electronic control of various devices in automobiles, a control electronic circuit unit equipped with a CPU, a power transistor, various connectors, etc. is installed in the vehicle body. Such electronic circuit units require large heat sinks to dissipate heat from built-in or externally provided power transistors, etc. For this reason, there have been restrictions on downsizing the electronic circuit unit.

(Problems to be solved by the invention) In automotive electronic circuit units, electric circuit patterns are formed on the case itself to reduce wiring, heat generating circuit elements are placed directly on the case, and heat is dissipated from the case itself. This is intended to reduce the size of the entire unit and improve operational reliability.

(Means for solving the problem) In an electronic circuit unit for an automobile, at least the upper cover body and the lower cover body forming the case are formed of an enameled substrate on which printed wiring is formed, and the lower cover body fixed to the vehicle body is A heat-generating circuit element is disposed so that the upper cover body, the lower cover body, and the built-in circuit board are electrically connected during assembly.

(Function) According to the above configuration, since the circuit pattern is formed on the upper and lower lids that make up the case, wiring of the power line can be omitted, and the case itself has a high heat dissipation property, so it is specially designed. No heat sink is required, and the electronic circuit unit can be made smaller.

(Embodiment) A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an external view of, for example, a circuit unit for electronic control installed on the body of an automobile. In this figure, 1 is a part of the car body, 2
is the electronic circuit unit case. The illustrated part of the case 2 is the upper lid body 3. An input/output connector 4 is connected to the upper lid body 3 at a connector receiving part 5,
A large number of wire harnesses 6 are connected to the input/output connector 4. Furthermore, an optical link connector 7 and other connector connections are formed.

FIG. 2 is an exploded perspective view showing the inside of the electronic circuit unit. In FIG. 2, numeral 3 represents the upper lid, and numeral 9 represents the lower lid that is fixed to the vehicle body. The upper lid 3 forms a box whose back side is open in the figure, and the lower lid 9 is formed into a flat plate shape. The upper lid 3 is attached to cover the lower lid 9.

For example, a circuit board 10 is disposed within the space of the case 2 formed by the upper lid 3 and the lower lid 9. IC elements 11 and the like are arranged on the circuit board 10,
Configured as a control CPU board. The number of circuit boards 10 is arbitrary.

The upper lid body 3 and the lower lid body 9 are formed of an enamel substrate having an enamel layer 13 provided over the entire outer peripheral surface of an iron plate 12, as shown in FIG. Conductors, resistance circuits, etc. are provided on the inner surfaces of the upper cover body 3 and lower cover body 9, which are enamel substrates, by screen printing to form a required circuit pattern. The circuit pattern 14 constitutes electrical wiring.

Further, in the lower lid body 9, as shown in FIG. 2, transistors 15... and power transistors 16
… and power MOSFET 17… are diode 18…
etc. are wired. That is, circuit elements that relatively easily generate heat are provided.

Note that the circuit board 10 can also be constructed of an enameled board. Moreover, the IC element 11 is directly installed inside the upper lid body 3 without using the circuit board 10.
It is also possible to configure a circuit by arranging

The upper lid body 3, the lower lid body 9, and the circuit board 10
Piece-shaped terminals 19 are formed at corresponding predetermined positions. When the electronic circuit unit is assembled, the electric circuits of the upper cover 3, lower cover 9, and circuit board 10 are connected via the terminals 19.

Incidentally, as shown in FIG. 3, the lower lid body 9 is fixedly attached to the vehicle body 1 with silicone 20, for example. Thus, the lower lid body 9 has a role as a bottom plate in the electronic circuit unit case 2.

According to the above configuration, enamel boards are used for the upper lid body 3, the lower lid body 9, and the circuit board 10 as necessary,
Since the electrical wiring is formed by forming a circuit pattern on the predetermined surface, it is possible to reduce the amount of wiring using lead wires. Furthermore, since circuit elements that generate a large amount of heat are disposed particularly in the lower lid body 9, and the enamel substrate has extremely good heat dissipation properties, the heat dissipation efficiency of the entire electronic circuit unit can be made high.

Furthermore, the enamel substrate itself has an electromagnetic shielding effect, and therefore it is possible to prevent malfunctions of internal IC elements without using a special shielding member.

Furthermore, since the drive circuit elements are concentrated and provided in the lower lid body 9, replacement is easy, and maintenance of such circuit parts can be improved.

(Effect of the invention) As is clear from the above explanation, according to the invention,
Since wiring is omitted and no special heat sink is required, the entire unit can be made thinner and more compact.The improved heat dissipation improves the environment and improves the heat resistance and operational reliability of the circuit. be able to. In addition, since the number of wiring materials such as lead wires can be reduced, the internal structure is simplified and manufacturing is easier.
Mass productivity improves.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of an automotive electronic circuit unit attached to a vehicle body, FIG. 2 is an exploded view, and FIG. 3 is a sectional view taken along the line -- in FIG. 2. In the drawings, 1 is a vehicle body, 2 is an electronic circuit unit case, 3 is an upper lid body, 4 is an input/output connector, 5 is a connector receiver, 9 is a lower lid body, 10 is a circuit board, and 11 is a
IC element, 12 is iron plate, 13 is enamel layer, 14
is a circuit pattern, 16 is a power transistor, 1
7 is a power MOSFET.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A case that is attached to a vehicle body is composed of an upper cover body and a lower cover body, the upper cover body and the lower cover body are formed of an enamel substrate, and an upper cover body made of the enamel substrate. An electric circuit for an automobile is provided by printing and firing a conductor on the lower lid body, and the electric circuits of the upper lid body and the lower lid body are connected via terminals arranged on the sides of each lid body. circuit unit. (2) Claim 1 of the above-mentioned utility model registration, characterized in that the lower lid body is fixed to the vehicle body, and circuit elements that generate a large amount of heat are arranged in a concentrated manner on the lower lid body.
The electronic circuit unit for automobiles described in Section 1.