Could someone please give me a general guideline concerning the additional
cost of using blind vias on a PCB?  Perhaps there is someone out there in
the PCB fabrication business or a fellow designer that has done some
extensive research into this?  We don't have need for buried vias, yet, but
are using more CSP packages (.5 mm pitch with .3 mm pads) that require blind
micro via-in-pad in order to get the signals out of the center pads.  An
added challenge is that we are also required to have 50-ohm controlled
impedance micro-strip lines.  This makes it rather difficult to use very
small micro-vias, due to the restricted aspect ratio of ~ .7:1.  TIA, for
any information you can provide.

Ray Humphrey
Senior PCB Designer
Maxim Integrated Products

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