Tom, Are these doublesided or multilayer PCB's???? Tell us alittle about the board. Groovy -----Original Message----- From: Tom Oliver [mailto:[log in to unmask]] Sent: Thursday, August 26, 1999 8:03 AM To: [log in to unmask] Subject: [TN] PCB material shrinkage Hello My first post and first question to the experts. I am new to the electronic game most of my experience has been in mechanical inspection and test. My question: is there a rule of thumb on material shrinkage on board material or a spec. Our boards are coming in with all the dimensions at nominal but after wave they have shrunk down to the low limit and sometimes below low limit. Most of our tolerances are +/- .003. This is giving us headaches with interference problems when we put other components on the boards. Is it normal for the boards to shrink. Our arrays are approx. 4" x 12" with 25 separate boards on each array. Thx's in advance Tom Oliver Eagle Comtronics [log in to unmask] ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ############################################################## ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################