[SOLVED] Solder mask defined pads

[arunmaran10]

Hi All,
I am using 81 pin WLCSP package IC. In socket recommended pad dia is 0.3mm. But for 0.4mm pitch suggested pads is 0.265mm pad.

This is not matter for socket still i have to connect 2,3 pads diagonally in top layer. To do this i have to reduce some pad size. I need to know whether different pad size will affect assembly. Because i have doubt that there may be chance of short with adjacent pads during wave or re flow soldering if we have different pad size.

This is the case if i want to solder device in socket board.

Regards,
Arunmaran

 

[vigneshg05]

Can you please tell what's the Pitch of your WLCSP package and send some snapshot of your socket.

Reg assembly Issue: Pls check with your assembly house depends upon her capability only we will decide.

 

[marce]

Yes different pad sizes will affect assembly.
This device will have to be reflowed, you are not going to wave solder a device of this pitch.....
Why do you have to reduce the pad size to join the pads?

 

[arunmaran10]

Hi Marce,
Because 0f 3.5mill trace width/spacing i have to reduce pad size.

 

[marce]

Have you a link or device name?

 

[arunmaran10]

https://192.168.1.10:18080/svn/SHUBH/Docs/TI/TPS659122 Features - swcs079.pdf