Hi Vladimir,

I believe that this is a rejectable condition. IPC 6012, paragraph
3.3.4, states that there will be no lifted lands on an unstressed
printed board.

BTW - If you have a separation between the laminate and the copper then
you cannot have cratering because the copper is not adhered to the
laminate.

Sincerely,  

 

Paul Reid 

Program Coordinator  

PWB Interconnect Solutions Inc. 
235 Stafford Rd., West, Unit 103 
Nepean, Ontario Canada, K2H 9C1 

613 596 4244 ext. 229  

Skype paul_reid_pwb 
[log in to unmask] 

 


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir Igoshev
Sent: April 17, 2013 6:47 PM
To: [log in to unmask]
Subject: [TN] BGA pads

Techneters,

I have another tricky question.

We see separation at the Cu pad/laminate interface. The area is rather
small (20 microns in section), BUT it's located at the periphery of BGA
pads.

My concern is that the separation will act as a stress concentrator
causing pad cratering, once the BGA is placed. 

I'm positive it's a real scenario, as we investigated a similar case
over a year ago.

According to 6012C the board is acceptable (at least from my
understanding).

The question is: Is there a way  to legitimately reject the board?


Regards,

Vladimir

SENTEC Testing Laboratory Inc.
11 Canadian Road, Unit 7.
Scarborough, ON M1R 5G1
Tel: (647) 495-8727
Cell: (416) 899-1882
www.sentec.ca

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