JPH0648900Y2 - Circuit board - Google Patents

Description

TECHNICAL FIELD The present invention relates to a circuit board on which an electric circuit is mounted.

2. Description of the Related Art Conventionally, in this type of circuit board, an electric circuit is mounted on an insulative board, but at that time, a dedicated ground line is formed on the board to perform wiring. ing.

However, if such a wiring means is adopted, it is necessary to circulate each connection wire of the electric circuit and connect it to the earth line formed at a specific position on the board, which is a design problem of the circuit mounted on the board. Is a constraint.

Further, it is necessary to connect an earth line formed on the board and an earth substrate such as the body of an automobile with a dedicated wire harness.

Further, in the past, a heat sink is provided separately from the circuit board, resulting in a large size.

The present invention has been made in consideration of the above points, and the circuit board on which the electric circuit is mounted is used as a grounding body, and each circuit in the electric circuit can be freely arranged at any place on the circuit board without arranging a wire. (EN) A circuit board in which the constituent elements can be grounded, and the board itself can be grounded only by directly attaching the board to a grounding base, and the board itself is used as a heat dissipation plate. is there.

Configuration Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the circuit board according to the present invention, as shown in FIGS. 1 to 3, an electrically conductive metal plate 1 is coated on a substrate 3 covered with an insulating material 2 having good thermal conductivity such as enamel or ceramic. A circuit is mounted, and the surface of the substrate 3 on which the electric circuit is mounted is molded with an insulating resin 4 so that one circuit unit can be formed.

Therefore, the board 3 itself has good thermal conductivity, and it is not necessary to separately provide a heat radiating plate as in the conventional case, and the electric circuit mounted on the board 3 can be effectively radiated. become.

Bolt seats 6 having bolt through holes 5 are provided at both ends of the substrate 3, and conductive bolts 7 are passed through the bolt through holes 5 to bolt the substrate 3 directly to an earth substrate 8. By doing so, the metal plate 1 inside the substrate 3, the bolt 7 and the ground base 8 are electrically connected to each other so that the substrate 3 itself is grounded.

Therefore, by using the grounding means of the board 3 as described above, it is not necessary to electrically connect the board and the grounding base with a wire harness as in the conventional case, and the wire saving can be effectively achieved. As described above, the problem of disconnection of the wire harness for grounding does not occur at all.

At that time, a part of the metal plate 1 covered with the insulating material 2 is exposed to provide a mounting seat for the substrate, and the mounting seat directly mounts the substrate 3 on the ground base 8 to ground the substrate 3 itself. You can also choose to take it.

In FIG. 3, 9 indicates each wire harness that connects between each circuit constituent element in the electric circuit mounted on the substrate 2 and an external circuit or an external device.

Further, in the present invention, when grounding each circuit component in the electric circuit mounted on the board 3, as shown in FIGS. 4 and 5, the insulating material 2 on the mounting surface of the metal circuit of the board 3 is used. Via hole 10 is drilled and the via hole
The wire 11 is directly bonded to the 10th part so as to be connected to the metal plate 1 inside. In the figure, 12 indicates a bonding portion.

Therefore, the ground at a predetermined position of the electric circuit mounted on the substrate 3 can be freely set at an arbitrary position on the substrate 3 without winding the wire 11.
It is possible to effectively increase the density of the electric circuit mounted on the substrate 3.

In addition, when the wire 11 is bonded by the via hole 10, the bonding pad pulled out to the periphery of the via hole 10 as shown in FIG.
It is also possible to bond the wire 11 to the portion of 13.

However, if the wire bonding means by such a bonding pad is adopted, a step is generated in the lead-out portion A of the bonding pad 13 and the portion A becomes thin, so that the electric resistance of the portion A becomes large, The heat generation at the bonding portion becomes a problem.

However, in the present invention, since the wire 11 is directly bonded to the via hole 10 portion without pulling out any bonding, heat generation in the bonding portion does not become a problem.

Further, in the present invention, since the bonding pad is not pulled out at all, it is possible to effectively increase the density of the electric circuit mounted on the substrate 3.

In FIG. 4, 14 is a bare chip in which circuit components are integrated, and 15 is its chip component.

Further, in the present invention, as shown in FIG. 6, the substrate 3 is formed in a box shape having an open top surface, the electric circuit is mounted on the bottom surface of the box, and then the electric circuit is mounted on the bottom surface of the box. In addition, an insulating resin is poured into the box, and the resin is cured so that the electric circuit portion can be molded.

Therefore, by adopting such a means, a mold for molding is not required, the workability of the mold is improved, and the adhesion of the mold part to the substrate 3 is improved so that the reliability of the mold is improved. Get higher

Further, in the present invention, holes 16 are formed on the side surface of the box-shaped substrate 3 for passing the respective wire harnesses 9 connected to the respective circuit components in the electric circuit mounted on the bottom surface of the box, and the same. A clamp 17 for bundling each of the wire harnesses 9 at one side is integrally provided.

Therefore, by taking such means, the substrate 3
The wiring process of the wire harness 9 that connects between each circuit component in the electric circuit mounted above and the external circuit or the external device can be performed in an orderly manner, and the strength against pulling of each wire harness 9 can be made effective. You will be able to hold it.

As described above, in the circuit board according to the present invention, when mounting an electric circuit on a board in which a conductive metal plate is covered with an insulating material, the metal plate inside the board is used as a grounding body and then grounded. Via holes should be formed in appropriate places of the insulating material on the circuit board corresponding to each required circuit component, and the ground wire of each circuit component should be directly bonded to the metal plate inside the substrate through the via hole. With this, it is possible to freely ground each circuit component in the electric circuit at any place on the board without having to wire around it, and to effectively exert the heat dissipation effect by the board plate itself. It has the advantage of

Moreover, even when grounding each circuit component in the electric circuit mounted on the board, it is special that the wire is directly bonded to the via hole part that is opened in the insulating material and connected to the internal metal plate. There is an advantage that it can be performed optimally by taking means.

Further, according to the present invention, the board is directly attached to the grounding base by using a conductive bolt through a bolt through hole provided in the board, or a mounting plate in which a part of a metal plate covered with an insulating material is exposed. The substrate is attached to the grounding base by means of the above, and it has an excellent advantage that the substrate itself can be grounded when the substrate is attached.

Further, in the present invention, the board is formed in a box shape with an open top surface. An electric circuit is mounted on the bottom surface of the box, and an insulating resin is poured into the box to form an integrated resin. It has an advantage that molding can be performed easily and optimally.

Further, in the present invention, the box-shaped board is provided with holes for passing wire harnesses to be connected to the electric circuits mounted therein and clamps for bundling the wire harnesses on the outside of the board. Therefore, there is an advantage that wiring processing of each wire harness can be performed easily and appropriately while maintaining sufficient strength against pulling of the wire harness.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a circuit board according to the present invention, FIG. 2 is a perspective view of the board in the embodiment, and FIG. 3 is an electric circuit surface mounted on the board in the embodiment. FIG. 4 is a perspective view showing a circuit unit formed by molding, FIG. 4 is a partial perspective view showing an example of an electric circuit mounted on a substrate, and FIG. 5 is a side sectional view showing a wire bonding portion in the via hole. FIG. 6 is a perspective view showing another configuration example of the substrate, and FIGS. 7 (a) and 7 (b) are a plan view and a side sectional view showing a wire bonding portion in a conventional via hole. 1 ... Metal plate, 2 ... Insulation material, 3 ... Substrate, 4 ... Mold resin, 5 ... Bolt through hole, 7 ... Bolt, 8 ...
Ground substrate, 9 ... Wire harness, 10 ... Via hole, 11 ... Wire, 12 ... Bonding part, 16 ...
Through hole for wire harness, 17 ... Clamp

Claims (6)

[Scope of utility model registration request] 1. A circuit board for mounting each circuit component of an electric circuit on a substrate obtained by coating a grounded conductive metal plate with an insulating material, and corresponding to each circuit component that needs to be grounded. A circuit board characterized in that via holes are formed at appropriate places in the insulating material of the circuit board, and the ground wire of each circuit component is directly bonded to the metal plate inside the board through the via hole. . 2. The board according to claim 1, wherein the board is provided with a bolt through hole, and the board is directly attached to the grounding base by using the conductive hole by means of the through hole so that the board itself is grounded. A circuit board according to the item. 3. A metal plate covered with an insulating material is partially exposed to provide a mounting seat for the substrate, and the mounting seat is used to mount the substrate on a grounding base to ground the substrate itself. A circuit board according to the above-mentioned item 1. 4. A substrate is formed into a box shape having an open top surface, circuit components are mounted on the bottom surface of the box, and an insulative resin is poured into the box to cure the resin. The circuit board according to the above-mentioned item 1, wherein the circuit board is molded with a resin. 5. The box according to claim 4, wherein the side surface of the box formed by the board is provided with holes through which wire harnesses for connecting to respective circuit components mounted on the bottom surface of the box are inserted. Circuit board according to the description. 6. The box according to claim 4, wherein the box formed by the substrate is provided with a clamp for bundling wire harnesses connected to circuit components mounted on the bottom surface of the box. Circuit board.