Ernie, Just as you stated, it was probably a silicone rubber sheet, usually red in color. We use these often in lamination for leveling the load. Some of the rubber is good to about 345F.but will ooze oil above that temperature. We try to use a different rubber, black in color for higher temperatures, up to 390F. This oil is very difficult to remove from parts or panels. Best bet is to clean with IPA then give it a plasma cleaning with a mostly oxygen cycle. Good Luck Chuck Brummer Acuson Ernie Crump wrote: > 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 > --------------------------------------------------------------------------------- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------