We have had a vendor use a silicone rubber mat on his platen while bonding a heatsink to a polymide pwb, and we suspect that the silicone has become part of the pwb surface on the one side, as the UR coating process has produced fisheyes, and peelable coating, just on the one side. We use Bioact-7R, alcohol and then di water to clean in a proper monitored pwb washer, but the removal of silicone is very difficult. What cleaners are recommended for removing it, without destroying components, or leaching under the bonded heatsink? Thank you. Ernie Crump Raytheon Systems Canada. Phone 519-885-0110, fax. 519-885-1178 --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------