I believe you are discussing bare PWB's.  What about lifted lands during
component soldering caused by thermal stress?  I have gone through the
TechNet archives and I still don't have a clear definition of
acceptability/rejectability.  Can you please help?

>----------
>From:  Lisa Williams[SMTP:[log in to unmask]]
>Reply To:      "TechNet Mail Forum." <[log in to unmask]>,Lisa Williams
>Sent:  Wednesday, October 22, 1997 8:45 AM
>To:    [log in to unmask]
>Subject:       Re: [TECHNET] Lifted Lands per IPC-6012
>
>You got it exactly right.
>
>Lifted lands are NOT allowed when you are inspecting the board visually. If
>you can see the lift during a visual examination (usually done before thermal
>stress), then there is a problem and cause for reject.
>
>The thermal stress test method requires inspection by microsection. If you
>can't see lifted lands during the visual inspection, but you see it in the
>microsection...it is still okay.
>
>In fact a major OEM has postulated that if the lands lift during thermal
>stress the reliability of the PTH actually increases, because the FR4 can
>expand and contract independently of the copper (in other words the copper
>will not undergo as much mechanical stress).
>
>Lisa Williams
>IPC
>
>>>> APeder01 <[log in to unmask]> 10/21/97 03:15PM >>>
>     I'm a bit confused (not unusual) by two paragraphs in IPC-6012
>     regarding lifted lands.
>
>     3.3.4  Lifted Lands.  The finised board SHALL not exhibit any lifted
>     lands.
>
>     3.6.2.9  Lifted Lands.  Lifted lands are allowed after thermal stress
>     provided that the visual criteria of section 3.3.4 are met.
>
>     So, is this telling me that lifted lands are okay as long as I can't
>     see them?  (If I can't see them, how would I know they were lifted?)
>     Therefore, if there is visual evidence of a lift is it rejectable?
>     Was the intent to allow or dis-allow lifted lands after thermal
>     stress?
>
>     Thank you for any clarification.
>
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