Regis Froats wrote:
>
> Hi Mike,
>         I've been looking into this as well.  My first premonition is, the single
> ply of 2313 will have consistent density of glass bundles vs 2 plys of 106.
>  The consistent density will yield a more consistent via shape.  Remember,
> with 2 plys of 106 you might encounter 2 knuckles on top of each other,
> thus requiring you to set the laser power high enough to penetrate both;
> however, you will also likely encounter areas that are resin rich, which
> does not require as much power.  The excess power in the resin rich areas
> will give you an "egg" shaped via.
>    My 2 cents....
>
> At 07:05 AM 07/01/1999 -0700, you wrote:
> >I have a product that requires a .006 dia. laser ablated via from lyr 1 to
> >2.  I'm required to use glass re-inforced FR-4 as a dielectric.  The
> >dielectric is approx .0035. I can either use a single ply of 2313 or 2 plies
> >of 106 prepreg.  Which would be the most favorable construction in terms of
> >laser hole quality and subsequent processing?
> >
>
> --
> Regis Froats <[log in to unmask]>
> Process Engineer - Herco Technology Corp.
> 13330 Evening Creek Drive North
> San Diego, Ca. 92128
> Pho:619.679.2800 - Fax:619.679.7565


The 2 X 106 works fine. Don't know which is better hole quality though.
Might depend on the glass etch clean up.