US Patent 7150669 Electroluminescent panel and a manufacturing method therefor

A second planarization insulating layer disposed under an organic EL layer is heat-treated so as to bring the moisture content thereof to an extremely low level. By lowering this moisture content to 77 ng/cm3 or below, an organic EL panel can be realized where the degradation of luminescence characteristics is minimized. As an alternative method of reducing the adverse effect of moisture content on the organic EL layer, a reforming processing or coating processing may be performed on the second planarization insulating layer.