At 23:52 15/12/97 -0500, you wrote:
>As a board manufacturer, I would be reluctant to agree to a 0.7% (.007in/in)
>flatness requirement without first reviewing the design of the circuitry in
>question. It is absolutely imperative that the board design is optimized for
>board flatness before any  control can be achieved. I often state that the
>top five causes for non-flatness in todays products are, in order of
>significance:
>
>1) board design
>2) board design
>3) board design
>4) board design
>5) all other factors
>
>Dave Rooke
>Viasystems Canada

 David !
I just can add my signature to Your statement . How many times we are
discussing this problem with DESIGNERS !!!
Most of them do not care about our remarks such us :
non - symetrical construction regarding dielectric spaces
unballaced construction regarding signals , ground , VSS
unballanced copper
Most of the anwers are : YYY supplied such boards to me without asking all
question , so take the job as it is or I will go to someone else !
Edward

Edward Szpruch
Eltek Ltd - Israel
Tel  972 3 9395050
Fax 972 3 9309581
E-mail :  [log in to unmask]

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