Victor,

Sorry, I hit send earlier by mistake.

IPC-6012 is not very clear on LIFTED lands definition or requirement.

BUT MIL-PRF-55110 is.

Page 15  Para A.3.6.8
Page 50  Fig A-12.

According to the above this condition (even though not classical PTH) is not rejectable.   Maybe an issue long-term for your application.

And since this is "lifting with adhered base material"...I won't call it workmanship issue right away either.

What I would look at
1) Materials choice for the application...maybe you need to use something with better Z-axis expansion with Hole-fill matching the same.

2) How well the moisture is removed before you performed the thermal test?

Rush
Accurate Engg Inc
www.Accueng.com
818-768-3919

 

 

 

-----Original Message-----
From: Victor Hernandez <[log in to unmask]>
To: TechNet <[log in to unmask]>
Sent: Thu, Mar 14, 2013 5:44 am
Subject: Re: [TN] IPC-6012


Can someone quote chapter and verse if this is a rejectable anomaly.   In 
IPC-A-600F, "Non-Conforming - Class 1, 2, & 3   No lift allowed from the 
laminate plane to the bottom surface at the end of the copper land, whether or 
not resin appears on the copper land off the board."   Need judgment from the 
gurus as what that really mean and with photos to ensure the issue is well 
understood.

Victor,

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Paul Reid
Sent: Thursday, March 14, 2013 7:25 AM
To: [log in to unmask]
Subject: Re: [TN] IPC-6012

Hi Vladimir,
 
What you have here is a lifted pad. I think that that is rejectable to 6012. 
 
There appears to be an adiquate wrap of copper.
 
Best regards,
 
Paul Reid

________________________________

From: TechNet on behalf of Vladimir Igoshev. PhD
Sent: Wed 13/03/2013 5:18 PM
To: [log in to unmask]
Subject: [TN] IPC-6012



I have a question for boards gurus,

We run a set of tests to assess the workmanship of a PWB. The board had 
vias-in-pad (in essence PTHs overplated with Cu pads) under a BGA.

After a thermal stress the pads were partially flitted due to cracked laminated 
underneath them. To me it's a recipe for disaster  (like pad
cratering after assembly).     However, I saw nothing about it in
IPC-6012. Did I just miss it?

I'd really appreciate any contractive comments.

--
Best regards,

Vladimir Igoshev. PhD                          mailto:[log in to unmask]

SENTEC Testing Laboratory Inc.
11 Canadian Road, Unit 7.
Scarborough, ON M1R 5G1
Tel: (416) 899-1882
Fax: (905) 882-8812
www.sentec.ca

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________



______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

 

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________