Cleaning method for palladium removing solution on PCB

Abstract

A cleaning method for a palladium removing solution on a PCB comprises the following steps: (1) an ultrasonic treatment is performed on the PCB that previously undergoes etching and palladium removing solution cleaning by using a cleaning solution I in a cleaning tank, wherein an ultrasonic frequency ranges from 20 to 50kHz; ultrasonic time ranges from 10 to 60 seconds; a temperature of the cleaning solution I in the ultrasonic treatment process ranges from 25 to 35 DEG C, and the cleaning solution I is prepared by mixing sulfuric acid, ethylenediamine tetraacetic acid tetrasodium, a copper protecting agent and water together; and (2) spraying cleaning is performed on the PCB after being treated in step (1) by using a cleaning solution II, wherein a pressure of the spraying cleaning ranges from 15 to 25Mpa; cleaning time ranges from 20 to 60 seconds; a temperature of the cleaning solution I ranges from 25 to 35 DEG C; and the cleaning solution II is prepared by mixing sulfuric acid, hydrogen peroxide and water together. If the cleaning method provided by the present invention is used for cleaning the palladium removing solution, a better cleaning effect can be achieved, and the surface quality of the PCB can be effectively guaranteed; during automatic optical detection, less pseudo-points are found out; shorter scanning and detection time is taken; and higher production efficiency is achieved.

Description

technical field [0001] The invention relates to the production of a PCB board, in particular to a cleaning method for removing palladium liquid on the PCB board. Background technique [0002] With the development of the circuit board industry in the direction of high density and high precision, the surface treatment method of PCB boards has changed from the original method of spraying tin to the method of immersion gold. When the PCB board is sinking copper, palladium ions are adsorbed on the non-sinking copper holes, which leads to gold in the non-sinking copper holes when sinking gold. Therefore, after etching, the PCB board must be cleaned with a palladium removal solution to remove palladium ions. [0003] However, the remaining palladium removal solution on the board is not easy to clean, so that when the tin is stripped, the circuit becomes red and the board surface is foggy, similar to the phenomenon of unclean tin stripping or copper surface corrosion, which affects ...

AI Technical Summary

Problems solved by technology

It has a certain positive effect on removing the residual palladium solution on the PCB, but it is still not ideal