John Is changing to SM over Bare Cu not an option? -----Original Message----- From: mailnet Sent: Thursday, August 14, 1997 2:03 PM To: Andy R.J. McKean Subject: JOHN OSULLIVAN <[log in to unmask]>: [TECHNET] Solder mask material From: JOHN OSULLIVAN <[log in to unmask]> REGARDING Solder mask material With regard to different solder mask material I'm interested in finding out if some solder mask materials have differnet thermal masking abilities. The reason I ask is because of a board I am wave soldering which has heavy copper layers internally, which forces me to pass the board through the preheat stage (and over wave) very slowly. The board was manufactured using all over tin/lead reflow. The tin/lead under the solder mask on large tracks are reflowing grosely and causing the soldermask to bubble/blister and crack off, failing the infamous 'tape test'. Any comments.