In a message dated 09/26/00 5:36:50, [log in to unmask] writes: >Just some advice if possible. I have a board that shows a plating crack >in the barrel and another with a plating crack at the knee (corner). The >hole is a via .3mm (11.8 mils) with about 20 to 21 microns (~0.8 mils) of plating >(checked by micro section) This is a first this year and cannot find any cause. Could >someone out there give me a starting point please. Thank you first. >Frank Hi Frank, You do not tell us how thick the PWB is nor what thermal excursions it has seen. This information is crucial for a full understanding of what is going on. Also how uniform is the plating thickness (dog-boning), and what kind the strength and elongation values do you get on your mandrel samples? Has anything changed in your plating process? How automated is your plating chemistry maintenance process? However, generally it can be said that 20 microns is not what I would recommend as the optimal plating thickness for reliable vias; you should pl ate at least 25 microns or better yet 30 microns. Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 904-437-8747, Fax: 904-437-8737 E-mail: [log in to unmask], Website: www.engelmaier.com ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d ############################################################## 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 ##############################################################