JPH0344480A - Electroless plating vessel - Google Patents

Abstract

PURPOSE:To remove plating deposited on the inner wall of an electroless plating vessel in a short time with a small amt. of an etching soln. by forming a groove along the top of the vessel and allowing the etching soln. to flow downward from the groove along the inner wall of the vessel. CONSTITUTION:A U-shaped pipe 2 is laid along the top of an electroless plating vessel 1 and an etching soln. 5 is fed into the U-shaped groove 3 of the pipe 2. The etching soln. 5 overflowing the groove 3 flows downward along the inner wall 6 of the vessel 1 and the etching soln. 7 accumulated in the vessel 1 is circulated by a pump 4 and used again. Plating deposited in the vessel 1 is efficiently removed in a short time with a small amt. of the etching soln. 5, 7..

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an electroless plating tank.

(Prior Art) When forming a circuit on a printed wiring board by electroless plating, it is generally performed by filling a tank with an electroless plating solution and immersing the board in this solution.

However, if the electroless plating process is continued for a long time, the plating metal will adhere to the inner wall of the tank, reducing the plating deposition efficiency. For this purpose, conventionally, the tank is filled with an etching solution to the very top, and the etching solution is circulated by a pump to peel off the plating adhering to the inner wall of the tank.

<Problems to be Solved by the Invention> However, conventional stripping methods require a large amount of etching solution, produce a large amount of waste solution, are expensive to process, and are time-consuming.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks and to provide an electroless plating machine that can remove nails at low cost and in a short time.

(Means for Solving the Problem) In order to achieve the above object, the present invention has the following features: The present invention provides an electroless plating bath characterized by having a groove disposed along the upper end of the wall to allow an etching solution to flow and an excess thereof to flow along the inner wall of the bath.

(Function) A groove is provided at the upper end of the tank wall, and by flowing the etching solution into the groove and allowing the excess to flow along the inner wall of the tank, it is possible to etch away deposits deposited on the inner wall.

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

In FIG. 1, 1 is an electroless plating tank.

Reference numeral 2 denotes a U-shaped pipe provided along the upper end of the electroless plating tank 1, and the etching liquid 5 is flowed through the U-shaped pipe 71113. 4 is the etching liquid 5 flowing into the groove 3
This is a pump for circulating the etching liquid 7 accumulated in the flow tank 1 along the inner wall 6 of the tank 1.

In the above embodiment, the etching solution 5 is poured in excess along the line 3, and the excess amount is drained away at 4f! When the etching solutions 5 and 7 are circulated by the pump 4, the amount of etching solution required to remove the plating W1 attached to the side surface and bottom inner wall 6 of the tank 1 is measured. did. The etching solution consisted of a mixture of 48% sulfuric acid, 15ONy, and 400 kg of 35% hydrogen peroxide solution, diluted with industrial water.

As a result, the required amount of etching liquid was 5 tons in the example, whereas it was 15 tons in the conventional example, and the former was 15 tons compared to the latter.
I got away with 73.

(Effects of the Invention) As described above, according to the present invention, since the etching liquid is flowed along the inner wall of the tank, the plating deposited on the inner wall can be removed with a small amount of etching liquid, and the etching time required for waste liquid treatment is reduced. An electroless plating tank that can be shortened by the amount of liquid reduced can be obtained.

[Brief explanation of drawings]

The figure shows a cross-sectional view of an embodiment of the invention. 1... Electroless plating tank, 2... Piping, 3...
Groove, 4... Pump, 5.7... Etching liquid, 6
···inner wall.

Claims (1)

[Claims] (1) An electroless plating tank characterized by having a groove disposed along the upper end of the tank wall to allow the etching solution to flow and the excess to flow along the tank inner wall. .