METHOD FOR FORMING VIA HOLE OF HIGH-DENSITY CIRCUIT SUBSTRATE

PURPOSE:To improve quality and achieve a high-density packaging while conserving earth environment without breaking ozone layer by printing a thick-film dielectric paste on a circuit substrate and then applying ultraviolet rays via a glass mask negative and performing development with a specific dev...

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Bibliographic Details
Main Author TOMITA KIYOSHI
Format Patent
LanguageEnglish
Published 12.09.1995
Edition6
Subjects
CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS
ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
ELECTRICITY
MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
PRINTED CIRCUITS
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Summary:PURPOSE:To improve quality and achieve a high-density packaging while conserving earth environment without breaking ozone layer by printing a thick-film dielectric paste on a circuit substrate and then applying ultraviolet rays via a glass mask negative and performing development with a specific development agent. CONSTITUTION:A thick-film dielectric paste 4 containing a sensitized resin is printed on a circuit substrate 1 by a screen 3 for thick-film printing where the pattern of a large-diameter via hole 7 is formed by emulsion 2. Then, ultraviolet rays are applied via a glass mask negative 5 where the patterns of the large-diameter via hole 7 and a small-diameter via hole 6 are formed. Then, the mixed liquid of acetic ether or ester solvent medium as a development solvent medium and normal hexane or xylene or benzene as a development suppression solvent medium is used as a development agent for development. Further, the circuit substrate 1 is mounted on a spinner as the development system and is developed by the shower or puddle system, thus achieving a high-density packaging without breaking ozone layer on earth.
Bibliography:Application Number: JP19940028742