Graham, There should be a note on the fabrication drawing that indicates that all hole sizes are after plating unless otherwise specified. IPC-2221 provides guidance on how to select a hole size to meet a component lead requirement which would be a finished hole size. The fabricator selects a larger drill size to compensate for the amount of plating, or other finish, in the hole. Regards, Gary Graham Collins wrote: > Hello TechNet > A question about through-holes on a flex. We are having some debate about how to interpret a drawing. > > Specifically, if I have a drawing that says: > 1) fabricate per IPC 6013 type 4 > 2) tin-lead plating shall be per IPC 2221, method optional > 3) hole size is specified in the drill schedule as 0.028", plated, +- 0.003" > > Our debate is about the hole size after plating. Does the +- 0.003" apply to the solder coated hole, or is that a copper only size? Does IPC-2221 specify any maximum solder thickness? > > I'm an assembler, so unfortunately I don't have these two IPC specs at hand. > > regards, > > Graham Collins > Halifax Production Engineering > (902) 873-2000 ext. 6215 > > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 15.0 > 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 15.0 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 -----------------------------------------------------