Patent ID: 7586256

Claim:
A combined substrate and dielectric layer component for use in an EL laminate, comprising: a rigid substrate providing a rear electrode; and a thick film dielectric layer formed above the rigid substrate providing the rear electrode by (a) a thick film technique with a first ceramic material paste in one or more layers to a thickness of 10 to 300 μm, followed by drying, then pressing the thick film dielectric layer and the rigid substrate providing the rear electrode so as to produce a pressed thick film dielectric layer having reduced thickness, surface roughness and porosity, and then sintering the pressed thick film dielectric layer, the rigid substrate providing the rear electrode to form a pressed, sintered thick film dielectric layer; and (b) depositing a second ceramic material by a sol gel technique on the pressed, sintered thick film dielectric layer and then heating to form a sol gel dielectric layer to further smooth the surface of the pressed, sintered thick film dielectric layer, such that the thick film dielectric layer so formed has a dielectric strength which is greater than 5.0×10 6 V/m, and uniform luminosity over a scale of about 10 μm in an EL laminate, and said pressed, sintered thick film dielectric layer has reduced porosity and reduced thickness of 20 to 50% compared to a dielectric layer of the same composition formed by the same technique with drying and sintering, but without an intervening pressing step.