On Thu, 19 May 2011 07:39 -0700, jim wrote:

>  Where I work, we have some PCB's that have been populated by a contract
> manufacturer. Actually some were
>  populated by one CM and others were populated by a different CM.  But
> the phenomenon has been seen on all
>  boards, so it isn't just one CM's process that is causing the problem.=20
> We have checked with the CM's about
>  their process, and Samtec approved of both of the solder reflow
> profiles as well as the solder paste
>  application process.Anyway, each of the boards use a surface mount
> connector from Samtec.  When these=20
>  boards go through our production testing, which includes several cycles
> of hot (85C) and cold (-40C)=20
>  temperatures, we find that the solder bond between the PCB pad and the
> connector pin fails, which in turn
>  causes the unit under test to fail.

Is this lead or ROHS solder paste?

Bob

--=20
http://www.fastmail.fm - IMAP accessible web-mail

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.