[log in to unmask] wrote: > > snipped for brevity < > > Press fits were/are used primarily to permit wire wrapping of backplanes. Peter, I'll agree with "were", but for "are" I must dis- agree with you. (That's a first!) I see pressfit in all manner of high performance elec- tronics, from CPCI and VME-64X through to mega-bandwidth network gear. I believe it is popular in the complex spectrum because it spares a thermal excursion and is reworkable, both important on these .250" thick 20+ layer beasts, and as a non-soldered connection can be made in finer pitches. 2mm pitch is more than common and many more dense arrangements are showing up all the time. So from context you'll all know that I fall on the side of non-soldering, and take the -610 comment to regard single staked pins also. Meanwhile I've a new(ish) problem with pressfit. Due to the hole size and construction contstraints, a number of fab shops want to move away from HASL to IAg or ISn for the surface finish. I am suspicious both of the amount of insertion lubrication available in these finishes and also the long-term life when these are not dispersed in a soldering step. Any commentary out there on this? Thanks and regards, -- Jeff Seeger Applied CAD Knowledge Inc Chief Technical Officer Tyngsboro, MA 01879 jseeger "at" appliedcad "dot" com 978 649 9800 --------------------------------------------------- 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 -----------------------------------------------------