Hong Yuen Electronics Ltd. wrote:- >We used Morton Epic 200A & B Wet Film Solder Mask for a long time, from Mid >of November, 97. , we found that there were some residual on board after >Developing, all our Process and Equipments are >normal, This sounds like a problem with your drying cycle being too hot. If the temperature gets too high you will get partial polymerisation at the board surface and the resist will not develop off. If you are seeing this problem on one side only and are coating both sides before exposure, then it will be happening on the first side as this sees the drying cycle twice. If you can't solve the problem quickly, then you could consider exposing and developing the first side before coating the second side although this takes more time. Good Luck Paul Gould Teknacron Circuits Ltd Isle of Wight,UK ############################################################## 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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################