Phil The general philosophy I normally suggest is for the customer to specify the end point requirements wherever possible. Then allow the vendor to create a structure fitting these requirements. Before going into production, the two parties review the requirements and structure. A good example is never specify impedance, line width and dielectric thickness altogether; this over specifies the design. It is far better to specify the impedance and final board thickness; let the vendor find the design best fitted for your requirements. Best regards Lee J. Lee Parker, Ph.D. JLP Consultants LLC 804 779 3389 ----- Original Message ----- From: "Anslow, Phillip" <[log in to unmask]> To: <[log in to unmask]> Sent: Thursday, September 28, 2006 3:45 AM Subject: [TN] Build Structure Communication Dear Fellow TechNetters, Would you please share how you communicate your PCB build structures to PCB fabricators, or, if you are a fabricator, how those which are easiest to understand are presented to you. For copper, is it best to quote (i) Nominal start weight or thickness, (ii) minimum finished thickness to IPC-2221A tables before and/or after plating if applicable? For dielectric thickness, (i) specify value, (ii) give range (iii) leave open? Your advice and expertise is greatly appreciated. Many thanks and regards, Phil ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. ******************************************************************** --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------