Regarding SMOBC, liquid photo, what would (in general) be the maximum temperature and time a solder mask can hold before any deterioration occur in a reflow oven? Same question but for PCB built with standard FR4 material, 6-8 layers...what is the MAXIMUM temperature and time suggested in a reflow oven for this type of PCB ? Thank you in advance ALaberge At 02:03 PM 8/14/97 -0500, you wrote: >John, > >Rather than looking for a different solder mask material you might want to >change the board design to SMOBC (solder mask over bare copper). If >you change to SMOBC, the tin could not reflow & therefore cause the >solder mask to bubble & lift. > >>>> JOHN OSULLIVAN ><[log in to unmask]> 08/14/97 04:49pm >>> > 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. > >Dennis Ostendorf >aaeee2o @snds.com > >