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Wed, 18 Oct 2017 14:41:09 +0000
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Dell - Internal Use - Confidential  

How about IPC-2226?

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Zilber Gil
Sent: Wednesday, October 18, 2017 9:23 AM
To: [log in to unmask]
Subject: [TN] Pad lifting or lifted land

Fellow TechNetters:

I have a problem of lifted land (via`s pad) after reflow. More the 90% of the pads show it on both sides of the PCB (Vias are filled and cap plating).
According to IPC lifted land after thermal stress is allowed.
In many cases, a conductor is connected to these pads and in this case, the reliability of the connected area to the lifted pad is probably very poor (most of the PCBS worked after the assembly, but one show discontinuity. Many vias are under BGAs connected as a dog bone to the BGA pads).
I contacted the manufacturer and he told me that the PCBs are ok according to IPC thus they will not compensate us.


Now I have a few questions:
1. IPC did not mention any conductor connected to these pads, why? What about reliability issues in this case (obviously poor?)?
2. Do I have any case against the manufacturer?
3. At IPC 6012 and Mil-prf-55110 lifted land refer to the pad of the vias, but it is not verbally written. It is showed on the pictures (at the MIL). Thus, one can interpret that lifted land, i.e. component pad, can be lifted from the board and it is acceptable...?? (imagine a BGA "jumping" up and down during vibration... :) 4. After that issue, I am going to change our spec and not allowed any lifted land (before or after thermal stress).

Thank you for your inputs,

Gil Zilber
Elta Systems Ltd.
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