Patent ID: 7427422

Claim:
A method of forming an EL laminate of the type including one or more phosphor layers sandwiched between a front and a rear electrode, the phosphor layer being separated from the rear electrode by a thick film dielectric layer, comprising the steps of: a) providing a rigid rear substrate; b) forming the rear electrode on the rear substrate; c) depositing a first ceramic material paste above the rear electrode in one or more layers by a thick film technique to form a thick film dielectric layer having a thickness of 10 to 300 μm; d) drying and then pressing the thick film dielectric layer, the rear electrode and the rear substrate, using a sheet of non-stick material in contact with the thick film dielectric layer during the pressing step, to form a densified thick film dielectric layer with reduced porosity and surface roughness prior to sintering; e) subsequent to pressing, sintering the thick film dielectric layer, the rear electrode and the rear substrate to form a pressed, sintered thick film dielectric layer; f) 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 thick film dielectric layer; g) forming one or more phosphor layers above the sol gel dielectric layer; and h) forming the front electrode above the one or more phosphor layers, wherein the EL laminate so formed has an improved uniform luminosity over an EL laminate of the same composition but formed without the pressing step.