JPS62140489A - Printed circuit substrate - 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 [Technical Field] The present invention relates to a printed circuit board in which a bonding part for wire bonding and a contact part for contacts are formed on the same print.

[Background Art] Conventionally, when forming a bonding part for wire bonding, a contact part, and a contact part for a sliding contact on a printed circuit board, a board made of glass epoxy, etc. is used as shown in FIG. After forming the circuit conductor 2 on the circuit conductor 1, a soft layer 9 is plated on the parts where wire bonding is required, while selectively masking (covering and protecting) other parts, and where the contacts and sliding contacts are required. The parts are plated with a hard coating containing 10, which has good wear resistance.
It is necessary to sequentially and repeatedly form the bonding part 5 and the contact part 6 while masking or peeling off the surface of the mask, which is a complicated process. Furthermore, the positional accuracy of the mask varies, and the masking agent There was a fear that the residue etc. would seriously deteriorate the quality of the printed circuit board. In addition, 8 in the figure is a nickel layer of the circuit conductor 2.

[Objective of the Invention 1] The present invention has been made in view of the above points, and provides bonding parts for wire bonding and contact parts for contacts on the substrate surface without the need to mask or peel off the substrate surface. It is an object of the present invention to provide a printed circuit board that can form the following.

[Disclosure of the Invention] That is, the printed circuit board of the present invention has a circuit conductor 2 formed on at least one surface of a substrate 1, a hard layer 3 made of a hard material laminated on the surface of the circuit conductor 2, and a hard layer 3 made of a hard material.
It is characterized by laminating a soft layer 4 formed of a soft layer on the surface of the i3, and when used as a wire bonding part 5 as a double structure of a hard layer 3 and a soft layer 4. Since a soft surface layer 4 is used and a hard layer 3 is formed on the inner layer, it can be used as a contact portion 6 without any problem.

The present invention will be described in detail below based on examples. The substrate 1 may be a prepreg made by impregnating a base material such as plastic cloth with a resin face such as epoxy resin and drying it by heating, a laminate formed by laminating a plurality of prepregs, or a laminate formed by curing the resin into a plate shape. A resin plate or the like formed by the substrate 1 can be used, and the circuit conductor 2 is provided on at least one surface of the substrate 1.
is formed. The circuit conductor 2 is made of copper, copper/nickel alloy, etc., and can be formed by a normal printed circuit board plating method, and in this embodiment is made of copper/I 7 and a nickel layer 8. A hard layer 3 formed of a hard layer is laminated on the surface of the circuit conductor 2, and a soft NJ 4 formed of a soft layer is laminated on the surface of the hard layer 3. The hard layer forming the hard layer 3 is an alloy containing 0.1% or more of gold, a brightening agent such as nickel, impurities, etc., and has high hardness and excellent wear resistance. Further, the soft layer is made of gold with a purity of 99.9% or more and is soft. These hard layer 3 and soft layer 4 can be deposited by conventional electroplating.

In this way, the circuit conductors 2 on at least one side of the substrate 1
A printed circuit board having a hard layer 3 and a soft layer 4 laminated thereon is obtained.

A soft layer 4 is formed on the outermost surface of the circuit conductor 2, and wire bonding is performed using the surface of the soft layer 4 as a bonding part 5. The soft layer 4 is easily melted by thermocompression bonding, and therefore bonding can be performed with good adhesiveness. In addition, when used as a contact, the surface of the soft layer 4 is used as the contact part 6, and even if the surface soft layer 4 is peeled off due to wear, the hard layer 3 is connected to the soft layer 4. Since the hard layer 3 is the underlying layer, the hard layer 3 can be stably used as the contact portion 6. In this way, a printed circuit board having both the contact section 6 and the bonding section 5 can be manufactured in a rational and high quality manner, and also requires wire bonding between the external terminal surface and the internal wire bonding, such as an IC card substrate. This is particularly effective in fields where one side of both sides needs to be separated.

[Effect of the invention 1 As described above, the present invention forms a circuit conductor on at least one surface of a substrate, laminates a hard layer formed of a hard layer on the surface of the circuit conductor, and laminates a soft layer on the surface of the hard layer. Since the soft layers formed in the process are laminated, when used as a wire bonding part, the surface soft layer can be used as it is to bond wires with good adhesion, and it can also be used as a contact point. However, the inner layer has a hard layer with good wear resistance and can be used as a contact part without any problems.
Unlike the conventional method, there is no need to selectively mask circuit conductors on the surface of the board, and a printed board with stable quality can be easily manufactured.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts of a printed circuit board according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram similar to the above, and FIG. 3 is a sectional view of a main part of a conventional printed circuit board. 1 is a substrate, 2 is a circuit conductor, 3 is a hard layer, and 4 is a soft layer.

Claims (1)

[Claims] (1) Forming a circuit conductor on at least one surface of the board,
A printed circuit board characterized in that a hard layer made of hard metal is laminated on the surface of a circuit conductor, and a soft layer made of soft gold is laminated on the surface of the hard layer.