We are wave soldering double sided PHT boards using a No Clean flux. There is a proposal to replace the hot air levelled solder over bare copper(HAL ) finish with gold flash, about 5u inch thick, over 100u inch of nickel. The proposal would allow us to drop the carbon ink screening requirement used for contacts to a rubber keypad. I see no other benefits to this, only the following problems:- gold contamination of the solder pot and weaker solder joint strength. Does anyone know of any other benefits? Alan Shaw ############################################################## 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 ##############################################################