Hi
It is very difficult to say how much buldging is
required for sm. one has to define where you want to
fabricate the cards, it purely depeds on the pcb
fabricator's capability. a 1 mil mis registration will
cause 0.5 mil black out on the any one of the sides.
there are many soldermasking techniques/ many type of
materials each has its own ads and disads you better
contact the pcb fabricator and ask them how much
minimum they can accommodate for soldermasking.
however i am using 10 mil buldging and never gone less
than that, if i tell this to any european manufacturer
they will simply laugh at me, i understatnd most
european manufacturers's spell 5mil and less. any how
best of luck for your search
regards james m paul

--- "Bondarenko, Walt" <[log in to unmask]>
wrote:
> Hello Everyone,
>         A question has been brought to me.  What is
> the smallest soldermask
> relief to a surface mount pad being used in today's
> world.  I'm being told
> that a 5 mil relief is a good safe number, however,
> with parts that are 10
> mil pitch that a 3 mil or less should be used.  What
> have some of you run
> into?
>
> Walter Bondarenko
> PCB Designer
> Andrew Corporation
> Amplifier Products Division - AYP
> 281 Industrial Road
> Glen Rock, PA  17327
> (717) 505-0269
> [log in to unmask]
>
>


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