Hi David,

Think of rivets on a plane or ship. They are there to prevent a crack
from propagating. A hole (or void) will do the same trick. It does not
create a stress concentration (particularly in a ductile material like
solder) and therefore it can stop a crack ("swallowing" it). You can
take a look at the basics of Fracture Mechanics if you want to.

Regards,

Vladimir

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David Tremmel
Sent: Friday, February 22, 2008 1:29 PM
To: [log in to unmask]
Subject: [TN] Shrink hole voids

Hello TechNet Gurus,

 

I read an article that say that a shrink hole void (hot tear or sink
hole)
is not a crack, does not impact reliability, does not continue to grow
under
thermo-mechanical stresses.

 

This seems to go against my common sense and would venture to say adds
to
solder creep fatigue.

 

Would anyone like to comment on my comment and/or offer a link to where
I
can find more information?

 

 

I am a poor country and your two cents goes a loooooong way.

 

As always, thank you in advance.  

 

 

Thank you,

 

David Tremmel

Value Recovery

847 858-5540 - Cell

847 557-9574 - Office

847 557-9573 - Fax

 


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