Basic Chemistry of Novolaks

doi:10.1117/3.2265072.ch3

Book: Diazonaphthoquinone-based Resists

Author(s): Ralph R. Dammel

Published: 1993

https://doi.org/10.1117/3.2265072.ch3

Author Affiliations +

Abstract

The term "novolak" is derived from the Swedish work lak, meaning lacquer or resin, prefixed by Latin or Italian novo, meaning new. These "new lacquers" were indeed first used as such, as a synthetic ersatz for natural kopal resins from Sansibar, the Congo, or the Philippines, which were used in paints. Although a number of researchers had reported earlier on the possibility of manufacturing a soluble thermoplastic resin from the acid-catalyzed reaction of phenols and formaldehyde, it was Leo Baekeland in the US who first realized their commercial potential as substitutes for shellac, rubber, and the kopals. Crosslinking the novolak (a term coined by Baekeland) with hardening agents yielded a thermoset plastic, which he called Bakelite. Ludwig Berend at Albert Chemical Company, literally just across the street from Kalle AG, had been developing a similar commercial oil-soluble resin since 1904; it was commercialized at about the same time the Bakelite Company in the US and Bakelite GmbH in Germany took up production (1910). It was to the Albert resins that the Kalle researchers turned in their search for a suitable resin to impart film forming properties and improved development properties to the Suss lithographic material.