Yep it does seem odd, but here's how I would rationalise it: plasma etching could be doing two things: 1) activating surface to improve poor adhesion 2) reducing effects of moisture ingression when it does reach surface. Course, if you had a better adhering more protective product then maybe you could dispense with the plasma...... Mike Fenner ----- Original Message ----- From: Alan Brewin <[log in to unmask]> To: <[log in to unmask]> Sent: Friday, May 26, 2000 11:41 AM Subject: Re: [TN] Solder Mask > Jerry, > > It just doesn't make sense (to me anyway) to go to the effort of plasma > etching to get adhesion, and they to use a silicone material. Silicones > generally do not have good adhesion. I feel sure that if you use an acrylic > or urethane material (providing your board is pretty clean) you won't have > to plasma etch. > > Your comment about rework surprises me, I may be missing something? It has > always been my experience that acrylics are a lot easier to re-work than > silicones/RTV's. Do you want to chemically remove/rework or are you > soldering straight through the product? > > I also agree with Brian about the danger of relying upon reported dielectric > properties of a material measured at STP rather than at higher humidity if > these > conditions will exist in your end application. > > Alan Brewin > > Concoat Ltd ############################################################## 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 ##############################################################