Solution for removing printing board surface adhesion palladium and removing method

Abstract

The invention discloses a removing liquid of metal palladium in the printing circuit manufacturing course, which comprises the following parts: 65% nitric acid with density at 1-100g / L, 36% alcaine or hydrobromic acid or hydriodic acid with density at 10-300g / L, organic compound with nitrogen as copper preservative with density at 0.01-10g / L and aquacare or inducer or guanidine derivant as control agent of NO2. The printing circuit board is placed in the solution, which removes catalyst palladium on the insulating surface through spraying the circuit.

Description

technical field [0001] The invention relates to a solution and method for removing palladium attached to the surface of a printed circuit board, which is aimed at removing the electroless plating catalyst metal palladium remaining on the surface of an insulating layer after a metal conductor circuit is formed on the surface of the substrate in the production process of the printed circuit board . Background technique [0002] In the manufacturing process of printed circuit boards, the manufacturing process is roughening of the substrate (concave-convex surface), activation treatment (attaching metal palladium catalyst), electroless copper plating and electroplating copper, and then covered with an etching protective film to form a conductor After the part of the circuit and the rest are removed by etching, the etching protective film is removed to form a conductor circuit. On the surface of the insulating layer of the non-conductor, the reaction of the activation process is...

AI Technical Summary

Problems solved by technology

On the surface of the exposed insulating layer, there will be catalyst palladium residues. Due to the existence of residual metal palladium, it will become the activation source of the next step of electroless nickel plating, causing a short circuit between the copper conductor circuits. In addition, due to the trace metal between the circuits The presence of palladium will reduce the dielectric constant of the substrate and affect the transmission speed of the signal

[0005] In order to remove metal palladium attached to the surface of the insulating layer, Japanese Patent Laid-Open No. 63-72198 proposes to remove metal palladium with fluoroboric acid-sodium chloride mixed solution, and Japanese Patent Laid-Open No. 7-207466 proposes to use cyanide solution to remove metal palladium. Palladium, but the above-mentioned removal solution of residual palladium has the shortcoming of corroding the metal conductor circuit, and contains toxic cyanide. In addition, Japanese Patent Laid-Open No. The method of laser irradiation to remove the residual metal palladium on the surface of the insulating layer, but this method has damage to the insulating layer substrate