I encountered the mindset that started this thread too. This from NASA
trainers as they were introduced to J-STD-001. They were resistant to the
wave solder process. Bill, I empathize.

I do think one could make a case for hand soldering on thick boards with
high aspect ratio PTH, rather than subject a very complex and difficult to
fabricate board to multiple passes at reflow temperatures. 

Werner, in such a case, don't you think it might be possible to hand solder
SMT leaded parts and leadless passives with less strain at the PTH?

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier
Sent: Friday, September 14, 2007 12:46 PM
To: [log in to unmask]
Subject: Re: [TN] Military/NASA Spec Question

Hi,
If properly done, there is no reliability difference for hand- or
machine-soldered solder joints. HOWEVER, handsoldering subjects the PCBs to
higher temperatures with larger temperature gradients, and thus there are
reliability differences as far as the whole assembl;y is
concerned-hand-soldering should be m inimized to the largest extent
possible.



Werner

---------------------------------------------------
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
-----------------------------------------------------