Hello,
I found on the Internet MSDS of electroless deplating solution. Its composition is as follows in mass percent:
2% Thiourea
2% Citric acid
1,5% Tartaric Acid
3% Sulfuric Acid
DI water to 100%
So I made my own solution and it worked for pins. If pins were soldered dissolving was very slow- up to couple weeks. Final solution was colorless, I did
not made any attempt to precipitate gold yet.
I made larger batch of it and used it hot. the gold plating totally dissolved in just 20 minutes. So I put into this
hot solution much more e-scrap and left it overnight. Another day I was surprised, The plating was mainly untouched but some side reactions occured.
I suppose thiourea partially hydrolized and reacted with lead and tin, gols covered with some kind of stain. What could be the problem here? Any idea how to
properly manage this process? Is the composition correct?
I found on the Internet MSDS of electroless deplating solution. Its composition is as follows in mass percent:
2% Thiourea
2% Citric acid
1,5% Tartaric Acid
3% Sulfuric Acid
DI water to 100%
So I made my own solution and it worked for pins. If pins were soldered dissolving was very slow- up to couple weeks. Final solution was colorless, I did
not made any attempt to precipitate gold yet.
I made larger batch of it and used it hot. the gold plating totally dissolved in just 20 minutes. So I put into this
hot solution much more e-scrap and left it overnight. Another day I was surprised, The plating was mainly untouched but some side reactions occured.
I suppose thiourea partially hydrolized and reacted with lead and tin, gols covered with some kind of stain. What could be the problem here? Any idea how to
properly manage this process? Is the composition correct?
