We have not found any issues using same land patterns as for Pb.



There is some evidence relating to reliability to suggest you should

avoid lands extending under the non contact area of passive chip type

parts.



You might want to look at modifying stencil apertures - we get the

stencil bureau to do this based on our standard 1:1 land/stencil layer.

For Pb-F we have been trying "T" cut apertures on passives which seems

to work well (less paste under the contact with more paste behind on the

free land.



Regards,

Chris

 

-----Original Message-----

From: Leadfree [mailto:[log in to unmask]] On Behalf Of Rick Thompson

Sent: 10 January 2006 23:32

To: [log in to unmask]

Subject: [LF] Land Pattern Question



In reading some forums related to land pattern development and in

particular IPC-7351A, I've seen references to having to develop unique

land patterns for lead free circuit boards based on a particular device

manufacturer's package size.



Is anyone contemplating this as a viable strategy for lead-free PWB

layouts?



Thanks for your inputs.



 

Rick Thompson

Sr. SMT Process Engineer

CTS Electronics Manufacturing Solutions

 

+1 (805) 532-2800   x-193

[log in to unmask] 

www.ctscorp.com

 





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