December 2005
Photoresist Stripping for Fun and Profit
The PCMI was kind enough to invite me to talk
at their Fall Conference about one ofthe areas of
technology we like to think we are experts on…
photoresist stripping. But, given that I talk
WAY too fast, I decided to expand the talk to
the entire photoresist related process.
Photoresist is obviously the key to the PCMI
process, and most ofthe photoresists used in
PCM today are the negative working dry film
type, which are developed in 1% carbonate
solutions and stripped in strong alkali.
Photoresist can be thought of as a mass of
unconnected spaghetti strands packed together to
form the dry film. These spaghetti strands are
reactive, and when they are hit by light, they link
together (chemists call this cross-linking, to
confuse non-chemists), to form a solid, nonwater
soluble mass.
Rudy Sedlak, RD Chemical Company, Mountain View, CA, USA
