This sounds similar to a problem with WLP and double layers of Polyimide. They cure with a vacuum/hot Nitrogen balance to reduce the boiling point of the solvent helps to remove the solvent completely and remove any wrinkles. Bill Moffat _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk