Hi Werner, I am sure you are aware that what you say is correct, but, not quite, it is weight per square ft. This implies a thickness of copper. If you have one ounce of copper then one would say I have one ounce. Since it is not sold by weight it is sold by weight per surface area we can imply thickness. The problem is that the thickness varies because they requirement is weight per surface area and the thickness can vary across the surface and not violate the specification. Also the copper has as variable density due to organic inclusions etc. The copper and laminate companies sell copper by ounces/ft2 but we measure the thickness. One oz. copper is .0012 to .0014 thick. This is an industry standard and a convention. It is not scientifically correct but it is how the industry relates to the copper thickness vs. weight/surface area issue. PR -----Original Message----- From: Werner Engelmaier [mailto:[log in to unmask]] Sent: Thursday, June 05, 2003 2:11 AM To: [log in to unmask] Subject: Re: [TN] (2) Micro-inch to copper weight conversion..Error Alert Hi Paul, All of this is nice, but.......oz./ft2 is NOT a thickness--it is a weight. It does not convert to a fixed thickness value in any of the units you list. Sorry, Werner Engelmaier --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------