Method for analyzing chloride ion content in acid copper plating bath

Abstract

The invention discloses a method for analyzing chloride ion content in acid copper plating bath, which comprises the following steps that: a. moving 50ml of copper plating bath into a 300ml beaker, slowly adding zinc powder while stirring until the blue color just disappears, and replacing out metal copper; b. filtering the replaced metal copper and leaving white filtrate; c. after the filtrate is fully precipitated, adding 20ml of 0.1N AgNo3 standard solution and 1ml of NH4Fe(SO4)2 indicator into the filtrate, dripping with 0.1N KSCN standard solution until the filtrate becomes reddish, and recording the volume of the consumed 0.1N KSCN standard solution; d. calculating the content of chloridion in the acid copper plating bath through the following formula: Cl-(mg / l)=709(20NAgNO3)-NKSCNVKSCN), wherein the NAgNO3 is the equivalent concentration volume of the AgNO3 standard solution; NKSCN is the equivalent concentration volume of the KSCN standard solution; and VKSCN is the volume of consumed KSCN standard solution. The analysis method not only omits an expensive UV spectrophotometer but also overcomes the interference of Cu2+ blue color so as to analyze the C1- in the acid copper plating bath with conventional solution.

Description

technical field [0001] The invention relates to the field of solution analysis, in particular to an analysis method for chloride ion content in an acidic copper plating solution. Background technique [0002] The bright copper plating solution contains a small amount of CL - , so that the phosphor copper anode forms a thin layer of brown-black anode film, and the anode can be dissolved normally and smoothly. CL - If the content is too low, a stepped copper layer will be produced, while CL - If the content is too high, it will passivate the anode. For this reason, the bright copper plating solution CL - The concentration is preferably controlled at 40-60ppm, which requires correct analysis of CL in the acidic copper plating solution - concentration. [0003] CL - The analysis methods, commonly used methods are UV spectrophotometry and Mohr method, the former requires a more expensive UV spectrophotometer, the latter uses AgNO 3 standard solution to titrate CL - , usi...

AI Technical Summary

Problems solved by technology

However, due to the dark blue color of acidic copper, it interferes with the observation of the end point color, making the analysis impossible