My two cents would be, if this is what you are try to achieve than you might want to consider another surface finish. Depending on the size of the pads, copper area near or around the pads, if there are fine pitch on one side and/or the other side, the thickness variation might not meet your requirements. It also depends on whether the fabricator uses horizontal or vertical HASL machines. Horizontal will give you the best thickness distribution but not everyone has one. Scott B. Westheimer ----- Original Message ----- From: "Tempea, Ioan" <[log in to unmask]> To: <[log in to unmask]> Sent: Tuesday, March 09, 2004 2:31 PM Subject: [TN] Finish thickness for HASL > Dear Techons, > > I know that this issue has been discussed several times, but I would like to > check again for updates and new issues. > > What is a good specification for the thickness of the HASL finish, that > would not make it impossible for the PCB fabs and it would avoid me > receiving boards with 2-3 mils thick bumps on the fine pitch? > > Thanks, > Ioan > > --------------------------------------------------- > 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 847-509-9700 ext.5315 > ----------------------------------------------------- > --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------