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CCGA stencil design

JackT

#4636

CCGA stencil design | 17 March, 2000

Hi folks,

Is anybody have an experience in stencil design for CCGA ? Currently, I'm running with 5 mils thickness stencil and I encountered that there were defect on contact after reflow soldering process.

Appreciate your help !

thx..Jack

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#4637

Re: CCGA stencil design | 18 March, 2000

Jack: Two concerns with column devices:

1 Coplaniarity of the device and the board. 2 Adequate solder that you mentioned, becuase the columns will not be reflowing and you need to cloatthem with solder. You didn't describe your aperture, but even with 1:1, I'd say you need to be at least 0.006 inch. Check with IBM. They be able to help.

Good luck

Dave F

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Glenn Robertson

#4638

Re: CCGA stencil design | 20 March, 2000

Jack -

The last time I checked IBM was specifying a minimum of 4800 cubic mils of paste for each pad. This is required for acceptable reliability, not just to make the connection. There is no way you are getting that volume with a 5 mil stencil - typically an 8 mil is required. Just do the math. I agree that you need to contact IBM. They have lots of data and expertise in this process. Regards.

Glenn Robertson

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