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Activator for PCB and PTH not stable

2004

Hello:

My job is making printed circuit boards and printing through holes {PCB& PTH} in one of the co. of this industrial in Iran. In line for making this, we use a solution that made of palladium chloride, tin(2)chloride, hydrochloric acid and sodium chloride. This solution is the activator for copper electroless plating. I want a solution for stabilizing this solution? Because if this activator not using for long time, vitiating and problem is palladium chloride (pure) is very expensive.for example one gram of palladium chloride is 16 EUO. If you have more information of activator and other problems, please tell me.

Regards,

Kayvun Alipour
chemistry engineering - Shiraz, Fars, Iran

Stability is affected by absorbed copper and oxidation of the colloid.

Too much free acid will etch copper and poison the solution. Too little and the colloid drops out of solution.

A buffer of Potassium Stannate is useful, rather than adding a hydroxide to reduce free acid. There mush excess Tin 2 Chloride Your waste solutions can easily be recycled so that no Pd is wasted. Gold Chloride may be used rather than Palladium.

John Eddy
Electronics manufacturing - Canada
2004