| abstract |
A process for providing a metal-seeded liquid crystal polymer comprises the steps of providing a liquid crystal polymer substrate, applying an aqueous solution comprising an alkali metal hydroxide and a solubilizer, to etch the liquid crystal polymer substrate, and depositing an adherent metal layer on the etched liquid crystal polymer substrate using electroless metal plating or vacuum deposition of metal. When using electroless metal plating, a tin(II) solution applied to the liquid crystal polymer substrate, followed by application of a palladium(II) solution, provides a metal-seeded liquid crystal polymer. An aqueous solution, comprising from 35wt.% to 55wt.% of an alkali metal salt, and from 10wt.% to 35wt.% of a solubilizer, provides an etchant for the liquid crystal polymer at temperatures from 50°C to 120°C. A flexible circuit comprising a liquid crystal polymer film having through-holes and related shaped voids may be formed using the etchant compositions previously described. |