Stephen, Is it possible that the mask is over cured? Maybe somewhat embrittled? The problem seems like more of an adhesion problem as you suggested. If the mask in undercured, a thermal bump should give the mask some additional crosslinking. If the mask is a two part system, the shop may have had some component mixing problems or the mask pot life was nearing its end. Good luck, Mike Carano -----Original Message----- From: Stephen R. Gregory [SMTP:[log in to unmask]] Sent: Friday, February 11, 2000 8:12 AM To: [log in to unmask] Subject: [TN] Solder mask failing tape test.. Mornin' all!! This morning I got a email from one of our buyers telling me that one of the boards at one of our fab shops is being held-up because it doesn't pass their solder mask tape test. My buyer said that they told him that the mask is only coming off the via's, and it was because of uncured mask. The mask is a LPI and the via's aren't meant to be tented. Also the board doesn't go through wave solder as the only through-hole is hand soldered because it goes up through the board from the bottomside. My buyer is asking me if we should accept the boards. I have a few concerns. One thing is that if there is uncured mask at the via's, what guarantees are there that there isn't more at other places on the board? Shouldn't uncured mask be a simple thing to fix by either baking the PCB (if it's a thermal cure), or exposing it to more UV (if it's a UV cure)? Further still, does uncured mask come off in a tape test? Or is mask coming off from a tape test more an indication of an adhesion problem from contamination? Thanks in advance for all replies, -Steve Gregory- ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ############################################################## ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################