Q. Can you give me a titration procedure to check chloride concentrations in the PC-667 acid copper bath? R.V.
A. The plating bath being referred to is used in the printed circuit industry and is an Electro-Brite product. As I always suggest, you should contact your vendor to see if it has a standard procedure available for this test. A standard procedure is:
Using a 50 mL sample:
- Add 50 mL distilled water
- Add 25 mL of 50-percent nitric acid
- Add 5 drops 0f 0.1 N silver nitrate
- Mix sample thoroughly
- Titrate sample with 0.01 N Hg(NO3)2 to a clear endpoint
The chloride ion concentration (ppm) = mL of titrant x 709.1 x N
The data sheet for this particular plating bath specifies a chloride concentration of approximately 60 ppm.