Greetings, An inconsistency in our fab specs regarding etching/plating tolerance finds me at a mental "cross-roads" regarding this subject. The spec for some of our designs express the tolerance in the form of "mils" -- +/-.001, while other spec express the tolerance in the form of a percentage -- +/-10%. In one sense, on a design w/ .010 nominal lines and spacing, these two specs are the same. However, on a design w/ .005/.005 or .004/.004 lines and spacing, using a tolerancing method of +/-.001 vs. 10% has drastically different results. I would like to see any feedback on the pro's and con's of each method. What method do you use and why? -- Kelly Kelly Dack PCB Dsnr IGT (International Game Technology) Reno, NV --------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------