With regards to lifted pads, our experience is that the removal of non
functional pads dramatically increases the likelyhood of this problem. I
would recommend a review of the design and see whether non functional
internal lands can be added to reduce lifted lands. 

Question : do lifted lands actually cause a functional problem ???



Dave Rooke
Circo Craft - Pointe Claire Quebec Canada
Phone : 514-694-8400
FAX   : 514-694-2696

>______________________________ Reply Separator
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>Subject: High Z Axis Expansion Board Materials
>Author:  [log in to unmask] at SMTPLINK-HADCO
>Date:    12/2/95 5:27 PM
>
>
>We receive questions about plating high Z axis expansion board materials.
> When the expansion from assembly soldering is too great, surface pads around
>the holes lift, or the plated barrel cracks.  Does anyone have a standard 
>practice to prevent these phenomena when using laminate with great amounts of
> Z axis expansion (we think more than 6%)?
>     
>Thicker plating in the hole?
>Alternate metals plated?
>     
>Dennis Fritz
>MacDermid, Inc.
>245 Freight Street
>Waterbury CT 06702
>Phone 203-575-5740
>     
>     
>
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