Production of insulating varnishes and multilayer printed circuit boards using these varnishes

摘要

An insulating varnish comprising a resin component, electrical insulating whiskers, and if necessary, one or more additives such as an ion adsorbent, and/or an organic reagent for preventing injury from copper, produced by adding the additives to the resin component and the whiskers, or filtering the whiskers, or milled by using a beads mill or a three-roll mill, or the like, is excellent for producing a multilayer printed circuit board having high wiring density, high reliability and excellent other electrical properties.