Pad lifting criteria is applicable at any point in the process. The reason is that many, many SMT pads now have trace connections to the bottom of the pad going down in the Z-axis, into the PWB. So if there is any evidence of pad lifting, the reliability of the trace connection to the bottom of the pad may have been compromised. So just because it is after conformal coating, at test, or shipped to the customer, or out in the field matters nothing, it still needs to be addressed. Disposition of this defect, once discovered, is AABUS, and the disposition for repair, use-as-is, no-defect, rework by coating, etc, is also most strongly influenced by whether the pad has a vertical trace connection (not easily inspectable), surface trace connection (usually easily inspectable) or is not used electrically (no trace connection to anything).
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir Igoshev
Sent: Wednesday, March 12, 2014 12:47 PM
To: [log in to unmask]
Subject: Re: [TN] PWB, pad lifting
Hi Victor,
It's a VERY bad thing to see even a partially lifted pad. IPC is talking only about visual, but in. MANY cases it won't be detectable during visual.
Regards,
Vladimir,
SENTEC
Sent from my BlackBerry 10 smartphone on the Rogers network.
Original Message
From: Victor Hernandez
Sent: Wednesday, March 12, 2014 1:40 PM
To: [log in to unmask]
Reply To: TechNet E-Mail Forum
Subject: [TN] PWB, pad lifting
Fellow TechNetters:
Is there any additional criteria for pad lifting others than IPC-A-610D sections 10.2.9.2? Is this for Time Zero and/or post reliability testing>
Victor,
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