Patent ID: 7082669

Claim:
A method of manufacturing a substrate of a rotary encoder, comprising: (a) an etching step comprising etching a resin substrate, in which metal foil is bonded to the resin's substrate front surface and back surface so as to form first and second ring-shaped electrode patterns provided concentrically around a center hole, and a third ring-shaped comb electrode pattern on an outermost periphery as electrode patterns; (b) a plating step comprising metal-plating the first, second and third electrode patterns of said resin substrate; (c) a resin varnish applying step comprising applying and surprinting resin varnish into a concave portion of the substrate surface including the third ring-shaped comb electrode pattern after the etching, and removing excessive resin varnish from the surface of the concave portion of the substrate surface including the third ring-shaped comb electrode pattern; (d) a resin varnish curing step comprising heating and compressing said resin substrate so as to cure the resin varnish surprinted into the concave portion of the substrate surface including the third ring-shaped comb electrode pattern; and (e) a polishing step comprising polishing and removing the excessive varnish remaining on the metal surfaces of the electrode patterns so as to flatten the surfaces of the electrode patterns.