🚀 go-pugleaf

On Fri, 24 Jul 2009 13:19:18 +1200, "geoff" <geoff@nospam-paf.co.nz>
wrote:

>Archimedes' Lever wrote:
>> On Thu, 23 Jul 2009 10:58:49 -0400, "Michael A. Terrell"
>> <mike.terrell@earthlink.net> wrote:
>>
>>>   Most of what we used were marked with a two character code.  The
>>> cheaper suppliers were unmarked.
>>
>>  Wrong again.  Markings fell out of vogue as part size decreased to
>> the point where it was labor intensive to even examine the marking.
>
>What labour ?
>
>geoff 
>
  Now, in the modern facility, post assembly inspection doesn't really
even happen any more as it relates to part values.  Most post reflow
inspection is for locating any tombstoned or pad shifted parts.

  BGA requires X-ray to inspect.

  There was a time, however, when a post process inspector would actually
examine the discreet parts on an assembly, and verify the value of parts.
This was particularly true of a first article assembly, prior to a
production run.

  Now that form factors are so small, actual part value verification on
assemblies is rare.  It is also more difficult. Even with the
magnification aids.

  And the likelihood that a test or repair technician would know how to
read a chip cap with anything other than a meter is very, very close to
nil.