JPH02278894A - Printed circuit board - Google Patents

Abstract

PURPOSE:To improve thermal dispersibility by providing cores of copper foil layers in a plurality of layers, extending a plurality of holes formed with metal films on the inner faces over the layer cores, and connecting the plurality of cores via metal films. CONSTITUTION:Copper foil layer cores 1 having a plurality of layers in a laminated board 2 are exposed at the ends on the end faces of the board 2. The cores 1 are opened with blind type holes 3 at the intermittent positions of the board 2, formed with metal films 4 and connected by plating the inner faces of the holes 3. The board 2 is composed of a resin layer 5, a pattern 6, a through hole 7, and the upper faces of the cores 1 of uppermost side are exposed in a recess 8 for placing a component to be mounted such as an IC, etc. Accordingly, heat from the component on the board is dissipated from the ends exposed on the end faces of the board through the cores 1 of the component side, and the other cores 1 connected through the plurality of metal films 4 of the inner faces of the holes. Thus, a printed circuit board of metal core type having excellent heat dispersibility can be readily obtained.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a metal core type printed wiring board.

A typical feature of metal core printed wiring boards is heat dissipation.

Conventional technology and its problems Traditionally, the heat dissipation of printed wiring boards has been improved by applying thin aluminum cores, but the heat dissipation required for packages that mount components that generate large amounts of heat, such as ICs, has not been met. is still not sufficient.

An object of the present invention is to provide a metal core type printed wiring board having excellent heat dissipation properties.

Means for Solving the Problems The above objects of the present invention are achieved by a printed wiring board having the following configuration.

A plurality of cores made of copper foil layers are provided inside, a plurality of holes each having a metal coating on the inner surface extend across the copper foil layer core, and the metal coating allows the plurality of copper foil layer cores to A printed wiring board characterized by being connected.

It is better that the hole is a blind type. Blind holes can be made at any location without being restricted by the wiring pattern.

Function: In the present invention, heat from mounted components such as ICs on a printed wiring board is transferred to the copper foil layer core on the component side and to other copper foil layers connected to the core through the metal coating on the inner surface of a plurality of holes. The foil layer cores emanate from the ends of those cores that are exposed to the printed wiring board end face.

That is, according to the present invention, heat is dissipated by the plurality of copper foil layer cores, so that the heat dissipation effect is high. Moreover, the core is copper,
It has better thermal conductivity than an aluminum core, and since the multiple copper foil layer cores are connected by a metal coating, heat propagation between the cores is efficient. Therefore, according to the present invention, excellent heat dissipation properties can be obtained that fully satisfy the order required for packages equipped with large heat generating components such as ICs.

In the present invention, the metal coating applied to the inner surface of the hole extending across the cores is used to connect the copper foil layer cores. By applying a metal coating to the inner surface by plating, it is possible to easily connect the respective copper foil layer cores in terms of manufacturing the board.

Effects of the Invention As described above, according to the present invention, it is possible to provide a metal core type printed wiring board having excellent heat dissipation properties, and it is also possible to obtain this in a simple manner.

Example Next, embodiments of the present invention will be described with reference to the accompanying drawings.

A plurality of cores (1) made of copper foil layers are placed inside the laminate (2) according to a conventional method. These copper foil layer cores (1) are
Its ends are exposed at the end faces of the laminate (2). Each copper foil layer core (1) is provided with holes, preferably blind holes, extending through these copper foil layer cores (1) at various locations in the laminate (2);
A metal coating is applied to the inner surface of the hole by plating for connection. In the figure, (3) is the hole and (4) is the metal coating. (5) shows a resin layer, (6) a pattern, and (7) a through hole. (8) is a recess/portion for mounting mounted components such as ICs, and the recess (8) is provided with the uppermost copper foil layer core (
1) The top surface is exposed.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG. 2 is a perspective view showing one embodiment of the present invention.
FIG. 2 is a longitudinal cross-sectional view of the printed wiring board shown in the figure. (1) Core made of copper foil layer, (2) Laminate, (3) Hole, (4) Metal coating, (5) Resin layer, (6) ...Pattern, (7)...Through hole, (8)...Recessed part Fig. 1 Fig. 2 (above)

Claims (1)

[Claims] [1] A plurality of cores made of copper foil layers are provided inside, a plurality of holes each having a metal coating on the inner surface extend across the copper foil layer core, and the metal coating A printed wiring board characterized in that the plurality of copper foil layer cores are connected. [2] The printed wiring board according to claim [1], wherein the holes are of a blind type.