Method of making a transparent touch screen switch assembly

Abstract

A touch-sensitive matrix switch assembly includes a pair of transparent insulating substrates having conductive row strips and column strips. The conductive row strips and column strips are separated by longitudinal extending channels, and an insulating spacer strip is deposited in each row channel and in each column channel. The substrates are mounted together with the row conductors extending transversely with respect to the column conductors. An air gap between the row conductors and column conductors is provided by the engagement of the row spacer strips against the column spacer strips. The space strips are formed by very small diameter transparent glass or polymer particles which are mixed with a transparent polymer adhesive in a volatile solvent. The glass or polymer particle/adhesive mixture is sprayed into the channels through a mask to produce a transparent, non-conductive glass or polymer deposit which is enlarged slightly out of the channel, thereby defining a spacer strip. In an analog touch switch assembly, spacer dots are applied onto the surface of a resistive sheet by pneumatically sputtering small diameter transparent glass or polymer particles which are coated by a transparent polymer adhesive.

Dependencies are inferred from the claim text.