There is a world of difference in the quality of laser cut stencils (and stencils in general). Smooth walls are preferred. Some laser stencil cutters provide smooth walls without electropolishing, others yield so rough a surface it doesn't help. Be careful, one prominent stencil vendor has a habit of charging for electropolishing and not doing it. Nickel plating is debatable. The same low surface tension properties that may cause paste to release slightly better has a negative impact on paste roll. Regards, Brad -----Original Message----- From: Todd Ness [SMTP:[log in to unmask]] Sent: Friday, July 10, 1998 2:13 AM To: [log in to unmask] Subject: [TN] Electropolishing Laser-Cut Stencils Hi all, We are currently having problems with a laser-cut stencil that is electropolished and nickel plated with 9-mil openings. The paste does not release well from the apertures. We are having to wipe after every print. The board is fixtured well and we have been using the same paste for the last two years. We had a different laser-cut stencil in production from a different manufacturer with the same 9-mil opening, but this stencil was not electropolised or nickel-plated. With this stencil, the paste release was excellent and we never had to worry about wiping. Does anyone have any input into whether or not laser-cut stencils should be electropolished and nickel plated? I have heard contradicting opinions on this subject. One source has said that you do not want to electropolish laser-cut stencils because the rough laser walls will give you a better paste release. Whereas, another source has said that the smooth laser walls will give you a better paste release. Also, what benefit does nickel plating give you? Does the paste tend to roll better with nickel plating? Do you tend to get more or less paste deposit on the boards with nickel plating? Does it increase the life of the stencil? Has anyone using laser stencils seen major differences between the quality of different stencil manufacturers? Any input into this subject would be greatly appreciated. Thanks, Todd ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################