Hello,

I have a couple of questions with regard to laser drilling of ceramics:

- during laser drilling, we have observed black spots around the drilled
holes, I am curious to know where do they originate from (earlier it was
believed that the emulsitone that was applied onto the  ceramic prior to
drilling lead to carbon deposits, but I find it hard to believe that carbon
doesnt get oxidized at high temperatures in an oxygen environment).
- secondly is there anyway to remove slags around the holes during the
drilling operation (say for e.g. by using coolants etc.), this is a concern
because when we remove the slag after the drilling operation by scrubbing,
we leave the substrate with plenty of scratches, so ideally I would like to
remove the slag as and when they are formed.

Thank you for your patience.
Regards,
Adnan Merhaba
Thin film process engineer
American Technical Ceramics
Jacksonville, Florida