JPS5835993A - Printed circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printed wiring board using an aluminum base body.

Conventionally, this type of printed wiring board has good heat dissipation properties and is excellent in dimensional accuracy and stability, so it has been often used for hybrid 10 and boards where parts that generate a lot of heat are packed together.

The present invention aims to reduce the size of such a printed wiring board.

In the present invention, conduction is established between the grounding part of the conductor wiring and the conductor wiring, and it is possible to easily connect to the ground from any position of the wiring, and moreover, it is possible to eliminate the grounding wiring from the conductor wiring. It is something that can be done. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be explained using the drawings of FIGS. 1 to 3, which show embodiments of the present invention.

FIG. 1 shows the basic structure of the printed wiring board of the present invention. In the figure, 1 is a copper foil, 2 is an insulating layer, 3 is a plating layer, and 4 is an aluminum base body.

FIGS. 2 and 3 show an example of the printed wiring board of the present invention, and show a state in which copper foil 1 and plating layer 3 are electrically connected by solder 5. FIG. Note that 6 is a hole provided in the insulating layer 2. Moreover, FIG. 3 is a top view of FIG. 2, and the dotted line portion 7 is a chip component.

That is, in this embodiment, the aluminum base body 4
A plating layer 3 with good soldering properties is formed on the top surface, an insulating layer 2 is formed on the entire top surface of this plating layer 3, a copper foil 1 is formed on the top surface of this insulating layer 2, and etching, blasting, etc. Then, excess copper foil 1 and insulating layer 2 are removed 919, and copper foil 1 and plating layer 3 are connected by solder 5 through holes 6 provided in insulating layer 2. In this case, since the four-layer structure shown in FIG. 1 is processed, it is versatile, but it is difficult to remove the insulating layer 2. Therefore, as another method, a plating layer 3 is provided on the top surface of the aluminum base body 4, a pre-designed pattern of the insulating layer 2 is printed on the top surface of the plating layer 3, and a copper foil 1 is printed on the top surface. The conductor wiring may be formed using the following method.

In the printed wiring board according to such an embodiment,
Aluminum base body 4. A plating layer 3 is provided on the plating layer 3, and an insulating layer 2 having a hole 6 such that the plating layer 3 is exposed at an arbitrary location is provided on the plating layer 3, and copper as a conductive wiring is provided on the insulating layer 2. A foil 1 is formed, and conduction is established between the copper foil 1 and the aluminum base body 4 through the hole 6. The aluminum base body 4 is used as a grounding part, and the grounding part is connected to the conductor wiring formed by the copper foil 1. Since it is not provided, the area of the conductor wiring is reduced, making it possible to achieve miniaturization, and the design of the wiring pattern becomes simple. Further, by eliminating the ground portion from the conductor wiring, it is possible to easily increase the density of the wiring pattern. Furthermore, since the aluminum base body 4 has a shielding effect, electrical stability can also be improved.

As described above, according to the printed wiring board of the present invention, it is possible to eliminate the 1st bus part from the conductor wiring, thereby making it possible to reduce the size and simplifying the design of the wiring pattern and increasing the density. can be easily done,
Furthermore, electrical stability can be improved due to the shielding effect of the aluminum base body.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic structure of a printed wiring board according to the invention, and FIGS. 2 and 3 are sectional views showing a printed wiring board according to an embodiment of the invention. and a top view. 1... Copper foil, 2... Insulating layer, 3...
・・・Me, Tsuki layer, 4°°″°°°aluminum base body,
6...Handa, 66611. - Hole. 1θon

Claims (1)

[Claims] an aluminum base body, a plating layer formed on the top surface of the aluminum base body, an insulating layer formed on the top surface of the plating layer and provided with a hole through which the plating layer is exposed at an arbitrary location;
A printed wiring board comprising conductor wiring on the upper surface of this insulating layer.