JPS62128592A - Emamelled wiring 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] (Industrial application field) The present invention relates to an enameled wiring board.

(Conventional technology) It has a structure in which the wire is coated with enamel and a circuit is formed on the surface of the wire.
Compared to alumina substrates, it has various advantages such as being able to be made larger, having superior mechanical strength and impact resistance, being able to mount m1 parts, and having an electromagnetic shielding effect.

(Problem to be Solved by the Invention) However, the conventional enamel wiring board has the disadvantage that the circuit is formed with expensive conductive paste such as silver thread, resulting in a very high 1j, so it is not used much. . In particular, when through-holes are provided on a crawler wiring board, it is necessary to print conductive paste on both sides and then introduce the paste into the holes by suction, which results in poor workability.
There were many defective parts and the connection reliability was low. Also,
Normally, when enamel is soaked in a plating solution and an adhesive for electroless plating is applied to the surface of the enamel, it has the drawback of reducing the thermal conductivity of the enamel, making it difficult to form circuits by plating.

The purpose of the present invention is to improve the above-mentioned drawbacks and to produce an enamel wiring board that can form a circuit by electroless plating without reducing the thermal conductivity of the enamel.

(Means for Solving the Problems) In order to achieve the above-mentioned objects, the present invention sequentially coats a metal plate with an adhesive and a plating base adhesive, To provide an enamel wiring board in which a circuit is formed by electroless plating on the surface of an adhesive layer, characterized in that a base adhesive layer mixed with boron nitride particles is provided.

(Function) According to the present invention, since boron nitride particles are mixed in the adhesive layer for the plating base, the thermal conductivity of the adhesive layer for the plating base is improved, and the heat of the coating is improved. Improves conductivity.

In addition, the amount of boron nitride mixed in the adhesive layer for the matte base is preferably in the range of 10 to 4 Qwt%, and 1
If it is less than Qwt%, the thermal conductivity will not be improved much, and 40
%, the adhesive strength decreases.

(Example) Hereinafter, the present invention will be explained based on examples.

First, a hole is made in the plate using iron (or gold). Next, this perforated metal plate is coated with enamel and formed into an enamel shape. After forming the waxy layer, apply a base adhesive containing boron nitrite to the surface of the layer and dry. After forming the plating base adhesive layer, a plating resist is printed in the opposite direction to the circuit pattern. After printing the plating resist, the metal plate is immersed in a phase ratio solution, the adhesive layer for the plating base is chemically roughened, and then washed. Dip and form a circuit.

Next, the conditions of each process were changed and differences in thermal conductivity were measured.

The manufacturing conditions were as follows: In Example 1) of the present invention, a 150 μm thick layer was formed on a 1.2 mm thick iron plate, and on the surface of the layer, a base adhesive containing 2 Qwt% of boron nitride was applied. (HA-21 manufactured by Hitachi Chemical Co., Ltd.) with a thickness of 25μ
Then, apply it, dry it, and then apply it! After forming an adhesive layer, it was chemically roughened and washed in a chemical solution consisting of borofluoric acid and sodium chromate, and then a layer of copper foil with a thickness of 25 μl was formed by electroless plating. The copper foil is then etched using a conventional etching method to form a circuit.

In addition, in Example 2 of the present invention, in Example 1), after forming the plating base adhesive layer, the plating resist ink (
Hitachi Chemical Co., Ltd.! +-I G M -02BK) was printed in a reverse pattern, and chemical I was printed in the same strip 1'F as in Example 1).
II and electroless plating to form a circuit.

As a conventional example, a substrate was used in which a circuit was formed on the surface of the wafer by S'Fi paste made of silver thread.

To determine the difference in thermal conductivity, a resistor was placed on one side of each sample, a current was applied, and the upper limit of humidity on the surface opposite the resistor was determined. As is clear from the table, the temperature rise in the inventive example is about 7% higher than in the conventional example, and the inventive example has higher thermal conductivity.

In addition, cracks were formed on the surface of the porcelain when the surface of the porcelain was directly cedar treated and subjected to non-electrolytic plating.

(Effects of the Invention) As described above, according to the present invention, since boron nitride is mixed into the plating base adhesive, thermal conductivity is improved and the cost is lower than when using root thread conductive paste. 1 west,
In particular, in the case of a through-hole board, one roll of enamel wiring is easy to manufacture and has high reliability.

Claims (2)

[Claims] (1) In an enameled wiring board in which enamel and a plating base adhesive are sequentially applied to a metal plate and a circuit is formed on the surface of the plating base adhesive layer by electroless plating, boron nitride particles are not mixed in. An enameled wiring board characterized by being provided with an adhesive layer for a base layer. (2) The amount of boron nitride mixed is 10 to 40 wt%
The enamel wiring board according to claim 1.