And if you follow the factor they obtain, you usually get poor yield or control on actual dielectric thickness. Alain Savard, B.Sc. Chemical Process Analyst CAE Electronics Ltd. e-mail: [log in to unmask] -----Original Message----- From: Lyle Wallig [mailto:[log in to unmask]] Sent: February 10, 2000 3:21 PM To: [log in to unmask] Subject: Re: [TN] PREPREG AGAIN It has been pointed out by several of the Technet responders that many factors are involved in making a prepreg thickness determination. I would like to add that a standard testing procedure used by prepreg producers for determining the prepreg pressed thickness is to take multiple plies of prepreg (i.e., 10 sheets or so) press them under some standard condition of pressure and temperature and time and then measure with a micrometer the pressed thickness of the stack. Dividing that thickness number by number of plies of prepreg used in the test is usually the number that appears in the product data sheet for pressed thickness. Regards, Lyle Wallig ############################################################## 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 ##############################################################