Outer line etching method of PCB (Printed Circuit Board) board with PTH (Plated Through Hole) inter-hole clamping line

Abstract

The invention discloses an outer line etching method of a PCB (Printed Circuit Board) board with a PTH (Plated Through Hole) inter-hole clamping line, and the PCB board with the PTH inter-hole clamping line is etched for many times. The method comprises the steps of: first, primarily etching a PTH inter-hole clamping line region with a fine line easily caused, cleaning the board after etching to a standard width, and sticking dry films on a PTH and the inter-hole clamping line region which are qualified in etching for protection; then, secondarily etching the board till lines with corresponding requirements are etched in other regions of the board; and finally, retreating the films. Compared with the prior art, the outer line etching method has the advantages that the etching width of the PTH inter-hole clamping line of the PCB board is guaranteed, the product quality is improved, and the problems of halfway etching and high product rejection rate are avoided under the premise of not reducing the thickness of a copper foil.

Description

Technical field: [0001] The invention belongs to the technical field of printed circuit board production, and in particular relates to an etching method for the outer layer circuit of a PCB board with a line between PTH holes. Background technique: [0002] When the PCB board is manufactured, it is usually necessary to drill holes on the PCB board to form plated through holes (PTH holes) to realize the conduction connection between the circuits. Etching is carried out, and the copper foil other than the circuit on the board is etched away by spraying the etching potion, and the circuit is retained. [0003] Since the convection current of the PTH hole and the edge of the hole is strong when spraying the etching liquid, the etching reaction speed in the PTH hole area is relatively fast, and the amount of side erosion of the corresponding line is relatively large, which will cause the line part of the PTH hole to be damaged. The line width becomes smaller. Especially for PCB...

AI Technical Summary

Problems solved by technology

[0005] For this reason, the purpose of the present invention is to provide a method for etching the outer layer of the PCB board with the line between the PTH holes, so as to solve the problems that the circuit etching between the PTH holes of the current PCB board is too thin and the product quality cannot be guaranteed.