Another aspect of the difference between immersion and electroless plating it the ease of use. Since electroless has the reducing agent in solution, in theory, it can plate on virtually anything, including dust, particles of pcb, tank walls, random thoughts of the wrong content, etc. Immersion plating is driven by the substrate, if there is no substrate of the appropriate type present, it does not plate, period. This implies that the bath is very stable, and also self limiting. Of course the self limiting aspect is a double edged sword, and can be both an advantage, and a disadvantage, depending on the thickness of plating required. In the case of Palladium, it also means that the immersion plating is more dense, and less porous. If you have ever used an immersion Tin bath, think of how it worked compared to electroless Copper, and you will get a good idea of the salient differences in the way they work. Rudy Sedlak RD Chemical Company ############################################################## 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 ##############################################################