Ioan, Try 1000 microinches maximum (1 mil) ... and require them to measure the finest pitch pad (20 mil pad width will usually have between 200-900 micro inches (I'm familiar only with vertical HASL...the horizontal HASL is supposed to be a lot more uniform) and still have sufficient coverage on the larger pads. If you specify that the larger pads are only covered, or have a minimum of 50 microinches, the fab guys should be able to make your boards without the large (2 mil) bumps on the small pads. Douglas Corbett -----Original Message----- From: Tempea, Ioan [mailto:[log in to unmask]] Sent: Tuesday, March 09, 2004 12:31 PM To: [log in to unmask] Subject: [TN] Finish thickness for HASL Importance: Low 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 -----------------------------------------------------