Greetings all,

A question has come up concerning the solder mask coverage over the "G"
coupon (cross hatch).  After reviewing in 3 locations TM (2.4.28.1) ; 2221
(12.4.6) ; and SM-840 (6.4) no mention is made to the distinct type of
coverage over the coupon.  The question is should the coverage be a
continuous flood over the hatch or should the coverage be a matching hatch
pattern over the copper only.  The thinking being that an adhesion problem
would be more readily detectable if the tape test were pulling over solder
mask squares over copper vs. pulling over an entire pattern of laminate and
copper.  Any thoughts on this.  Our spec wording just states coverage not
the type of coverage.  Anyone have a thoughts on this as too what would be
the most accurate test method.  Do we need a hatch over laminate and a
separate hatch over cooper to be most accurate?

Thanks for any input,

PS. The G coupon is up for review in the 2221 amendment 2 (fig 12-15) also.

        C. D. (Don) Dupriest
        Lockheed Martin Missiles and Fire Control - Dallas
        Electronics Manufacturing Engineering
        Mgr. - PWB Process Development
        Ph. 972/603-7724 fax: 972/603-3548
        Email: [log in to unmask] <mailto:[log in to unmask]>