MICROMINIATURE LAYERED PRINTED WIRING.
Quarterly rept. no. 3, 15 Dec 62-15 Mar 63,
PHOTOCIRCUITS CORP GLEN COVE N Y
Pagination or Media Count:
A technique for plating of copper in plated through holes less than .025 in. in diameter and more than two diameters deep has been developed. This technique consists of partial panel and partial pattern plating of the copper. Boards manufactured by this technique exhibited minimum plating buildup and minimum of undercut around the miniature plated through holes with a .002 in. rim around the periphery. Better con trol of plating currents has also been achieved. The final sequence of manufacturing processes required to produce microminiature layered printed wiring test pattern boards has been selected and all tooling has been manufactured. A new test pattern has been added for measuring dielectric withstanding voltage and insulation resistance between very closely spaced holes and conductors. Author