JPH0723974Y2 - High current circuit board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a large current circuit board.

[Conventional technology]

A conventional large-current circuit board is formed by forming a copper foil pattern on an insulating substrate and soldering a punched circuit conductor made of copper, aluminum or the like on the copper foil pattern in a reflow furnace.

[Problems to be solved by the device]

However, in the high-current circuit board configured as described above, when the copper foil pattern formed on the insulating substrate and the punched circuit conductor are integrated by soldering, the solder protruding on the insulating substrate is adjacent. In order to prevent contact with the punched circuit conductors, the space between adjacent punched circuit conductors should be 3
Not only does the circuit board increase in size because it must be taken up to 4 mm or more, but the punched circuit conductor may peel off during soldering. There is a problem in that the surface is so rough that it is difficult to print a solder resist or to form multiple layers of circuit conductors.

As a means for solving the above problems, a punching circuit conductor and a prepreg sheet (for example, glass cloth impregnated with epoxy resin and semi-cured) are laminated, and this is heated and pressed by a hot press to punch it on an insulating substrate. A large current circuit board in which a punched circuit conductor is embedded has been proposed.However, in this large current circuit board, the prepreg sheet softens when the punched circuit conductor and the prepreg sheet are laminated and heated and pressed by a hot press. Since the resin flows, the punched circuit conductor is likely to move, the positional accuracy of the punched circuit conductor is not stable, and the punched circuit conductor embedded in the insulating substrate may fall off.

Further, recently, two or more holes or projections are provided in the punched circuit conductor, and a convex portion or a recessed portion into which the hole or the projection fits is provided on the pressing surface of the hot press to improve the positional accuracy of the punched circuit conductor. Another method has been proposed (see Japanese Patent Application No. 1-152241).

According to this method, the positional accuracy of the punched circuit conductor is improved, but the punched circuit conductor may fall off from the insulating substrate as described above.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a large-current circuit board that is small in size and has no possibility that the punched circuit conductor will fall off from the insulating board.

[Means for Solving the Problems]

In order to solve the above problems, the present invention configures a large current circuit board in which a punching circuit conductor is embedded in an insulating substrate made of a prepreg sheet, and the punching circuit conductor is provided with a retaining portion. It was done.

[Action]

When the prepreg sheet is heated and pressed by a hot press, it softens once, fills the gaps in the punched circuit conductor 2, and then hardens.

Therefore, by providing the punch-out circuit conductor 2 with the retaining portion 3, it is possible to prevent the punch-out circuit conductor 2 from coming off from the insulating substrate 5.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG.
FIG. 1 is a cross-sectional view taken along the line XX in the drawing, in which 1 is a large current circuit board, 2 is a punched circuit conductor that constitutes the large current circuit board 1, and the punched circuit conductor 2 is a conductive material made of copper, aluminum or the like. 2 is formed by punching a flexible metal plate into a desired circuit pattern, and the side surface thereof is formed by a V-groove retaining portion 3 as shown in FIG.
Is provided. Reference numeral 4 is a through hole for mounting a component on the punched circuit conductor 2 and for leading out a lead wire.

Reference numeral 5 is an insulating substrate made of a prepreg sheet (for example, glass cloth impregnated with epoxy resin and semi-cured). The high-current circuit board 1 of the present invention is obtained by laminating a required number of the above prepreg sheets, and then stacking the prepreg sheets thereon. The punched circuit conductor 2 is placed, or the through hole 4 provided in the punched circuit conductor 2 is fitted and set in a protrusion (not shown) provided on the pressing surface of the hot press, and heated by the hot press. It is constructed by embedding the punched circuit conductor 2 in the insulating substrate 5 by applying pressure.

When the prepreg sheet forming the insulating substrate 5 is heated and pressed by a hot press, the prepreg sheet once cures, fills the gap between the punched circuit conductors 2, and then cures. By providing it, it is possible to reliably prevent the punched circuit conductor 2 from falling off the insulating substrate 5.

Further, since the large current circuit board 1 of the present invention does not use soldering, the interval between the adjacent punched circuit conductors 2 can be minimized, so that the large current circuit board 1 can be downsized.

The shape of the retaining portion 3 provided on the punching circuit conductor 2 is not limited to the V groove, and may be a protrusion as shown in FIG. Not only on the side surface of the circuit conductor 2, but when a punched circuit conductor 2 is provided with a cylindrical through hole 4 as shown in FIG. It is provided in.

[Effect of device]

According to the present invention, as described above, there is an excellent advantage that it is possible to provide a large-current circuit board that is small and has no possibility that the punched circuit conductor 2 will fall out.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG.
FIG. 3 is a sectional view showing another embodiment of the present invention, and FIG. 3 and FIG. 1: High-current circuit board, 2: Stamping circuit conductor 3: retaining part, 5: insulating board

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-19394 (JP, A) Actual Kaihei 2-45667 (JP, U) Actual Kaihei 2-45665 (JP, U) Actual Kaihei 2- 45666 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A large current circuit board having a punched circuit conductor embedded in an insulating substrate made of a prepreg sheet, wherein the punched circuit conductor is provided with a retaining portion.