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One Step Method of Chemically Producing Holes in Glass Based Dielectric Materials

IP.com Disclosure Number: IPCOM000094904D
Original Publication Date: 1965-Jul-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Phillips, SL: AUTHOR [+2]

Abstract

Top and bottom layers 11 and 12 of copper are etched to form top and bottom hole recesses 13 by standard printed circuit board techniques. Substrate 15 is comprised of epoxy resin 17 and embedded glass 19 as a fabric. Chemical removal of the substrate at the hole has advantages over drilling and punching. For a one-step process, 10-20 grams of solid sodium fluoride of reagent grade are dissolved in 150ml concentrated sulfuric acid having a specific gravity of 1.84. The epoxy resin is dissolved by the sulfuric acid at room temperature while simultaneously the glass is removed by hydrofluoric acid to make through-holes. This one-step etchant is agitated as by stirring or spraying.

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One Step Method of Chemically Producing Holes in Glass Based Dielectric Materials

Top and bottom layers 11 and 12 of copper are etched to form top and bottom hole recesses 13 by standard printed circuit board techniques. Substrate 15 is comprised of epoxy resin 17 and embedded glass 19 as a fabric. Chemical removal of the substrate at the hole has advantages over drilling and punching. For a one-step process, 10-20 grams of solid sodium fluoride of reagent grade are dissolved in 150ml concentrated sulfuric acid having a specific gravity of
1.84. The epoxy resin is dissolved by the sulfuric acid at room temperature while simultaneously the glass is removed by hydrofluoric acid to make through-holes. This one-step etchant is agitated as by stirring or spraying.

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