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Need a maskant to withstand 190deg; F and pH 12 plating process

2005

We need a maskant that will withstand 190F plating bath temperature and 12 ph solution. we need to hold .020 tolerance and are having trouble with our existing maskant not leaking when exposed to these conditions. Any advise would be much appreciated.
Sincerely,

Patti Kientz
Plating company - Santa Ana, California, USA

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First of two simultaneous responses --

What you are currently using would be a nice place to start. What else have you tried. What is the shape and finish of the part. Can you use solvent to remove the mask? What other constraints can you think of?

James Watts
- Navarre, Florida
2005

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Second of two simultaneous responses --

Most maskants are photopositive materials and are designed to operate at low pH and to be developed (or stripped) in high pH solvents. What you need is exactly the opposite, namely a photonegative photoresist that can be used at high pH and is processed with low pH solvents. You can get some basic formulations from textbooks on the subject, but the intricacies of photoresists are such that you will almost certainly need technical backup. It is therefore better to ask a professional supply house for their products. Try asking Kodak or one of the other photoresist suppliers for further advice.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2005

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