Steve; Joe lists the conversions that agree with NIST, the one posted by Edward is off by a magnitude of 10. From this page at NIST, <http://physics.nist.gov/Pubs/SP811/appenB8.html#M> http://physics.nist.gov/Pubs/SP811/appenB8.html#M 1 micron = 1 micrometer Also from the same page, to convert from microinches to micrometer multiply by 2.54 E-02 (Or as Joe stated 100 microinch = 2.54 microns or micrometer) Therefore 170 microinch * .0254 = 4.318 micrometer (microns). Already posted in this thread, 1 ounce of copper = 35 micrometer (microns) thick. 4.318 micrometer / 35 micrometer per ounce = 0.123 ounces of copper Or approximately 1/8 ounce of copper at that location. Your stack up requires 1 ounce Cu (after plating) so you only have 12.5% of that requirement. It doesn't matter if it is computed in the metric system or English, you still don't have enough copper. Robert Denbo Engineering Manager Midwest Printed Circuit Services, Inc. http://www.midwestpcb.com <http://www.midwestpcb.com/> -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Sunday, June 01, 2003 2:48 PM To: [log in to unmask] Subject: Re: [TN] Micro-inch to copper weight conversion... Hi Joe! The figures I got were from my fab vendor, so I'm totally confused now... Will somebody tell me if I have enough copper or not? There's been conflicting answers from everybody.... -Steve Gregory- --------------------------------------------------- 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 -----------------------------------------------------