Tom - The only requirement for HASL is that it covers the entirety of the lands and exposed copper areas. The thickness of the covering can vary from a few tenths (or less) of a mil to more than 2mil. If you are using extremely fine pitch components (.5mm or less) it is time to consider a better surface finish. Silver, ENIG, white tin, and OSP all offer superior flatness to the HASL process for fine pitch assembly. Talk to your assembly people and decide which is best for your application and their process. Jeffrey A. McGlaughlin CID Sr. Designer Battelle Memorial Institute Columbus Ohio [log in to unmask] -----Original Message----- From: Tom Parkinson - Quality System Manager - WinTronics, Inc. [mailto:[log in to unmask]] Sent: Monday, September 23, 2002 3:42 PM To: [log in to unmask] Subject: [TN] HASL Hello all, Have been looking for some kind of spec for HASL thickness and uniformity. Having problems with small to fine pitch parts where HASL is causing problems. Only reference I can find so far is in 2221 where it says HASL is checked not by mechanical thickness, but by the ability to solder per JSTD003. 003 only talks about being able to solder - not about variability of HASL causing problems. My SMT people are giving me a hassle about the HASL...... Any suggestions?? ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------