Hi,

 Silly question: What is a solder "Smile"? Crack?

Thanks,
Bob K.

-----Original Message-----
From: TechNet <[log in to unmask]> On Behalf Of Frank Kimmey
Sent: Wednesday, May 16, 2018 5:12 PM
To: [log in to unmask]
Subject: [TN] Solderjoint elasticity

Can anyone point me in a good direction to learn more about solderjoint
elasticity with SAC305.
We are seeing some issues with BGAs when they smile.
Type 2 fractures and the vendor recommends increasing the solderpaste.
This seems counter intuitive to me.
If it was SnPb I would go back and hunt some of Werner's research.
As it is Lead free I need some direction.
Any help is appreciated,
FNK

Frank N Kimmey CID+
Electrical Engineer/PCB Design

Verifone
1400 W Stanford Ranch Road
Rocklin, CA 95765
T: 916-625-1818
M: 916-833-9877

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