Nee hao Wee Mei,
When beding leads over a small radius, surface cracks can occur if the lead material is not  at least quarter-hard annealed or softer—these cracks typically do not cause any problems. HOWEVER, the photos you sent Steve show cracks substantially more severe—I concur with Vladimir that cross-sections are definitely called for  to make a more accurate assessment.
Werner

 


 

 

-----Original Message-----
From: Lum Wee Mei <[log in to unmask]>
To: [log in to unmask]
Sent: Fri, Sep 17, 2010 8:07 am
Subject: [TN] Crack and oxidisation on IC leads


Dear All,

 

During PCBA inspection, we noticed cracked line across the entire IC lead width 

at the knee location. It happen to the whole row on one side of the IC and we 

consider it a reject. However, our production subcontractor do not concur the 

component as reject. They said that the crack is only fine line and is unlikely 

to cause any major physical issue to the leads itself.

 

In another IC, we noticed a small area of oxidation on one of the lead of about 

1 - 1.5mm in size. Again the subcontractor do not accept our decision that it is 

a reject. The reason given by them is that although the corrosion exposed the 

base metal it is acceptable because the exposed surface is not part of the 

required solder fillet.

 

I have tried to upload the photo on IPC Technet but not successfully. Hope from 

your experience, you can provide some opinions.

 

Thanks and Regards,

~ Wee Mei ~



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