Hi TechNetters, We do some testing of bare board right now. Can anyone point out what different between board with solder mask and without solder mask on electrical testing process? If we apply 250 voltage on 3.5 mil spacing pattern , will it damage electrical character? Is there copper migration occuring during 250 voltage testing? Howard Lin ############################################################## 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 Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################