Method of manufacturing the substrate of an electrochromic display cell

Claim 1

Method of manufacturing the substrate of an electrochromic display cell comprising the steps of providing a transparent and insulating plate; depositing successively, on the whole surface of the said plate, a layer of a transparent conductive material, a layer of an electrochromic material and a layer of a material which is positively sensitive to a radiation; exposing selectively to the said radiation a portion of the said sensitive layer; selectively eliminating the said exposed portion; etching successively the said electrochromic layer and the said conductive layer at the places exposed by said selective elimination so as to form, with the rest of the said conductive layer, a network of transparent conductive elements constituted by control electrodes situated at the places of the patterns to be displayed, terminal connection contacts of the cell and tracks connecting the said electrodes to the said contacts; exposing the remainder of the said sensitive layer, except at places corresponding to the said patterns to be displayed, and selectively eliminating the exposed portions of the said remainder of the sensitive layer; etching selectively the remainder of the electrochromic layer at the places exposed by this latter selective elimination; depositing a layer of a transparent dielectric material on the whole surface of the said substrate, except in the regions of the said contacts; and eliminating successively the remainder of the said sensitive layer with simultaneous elimination of the dielectric material carried thereby, the substrate being thus covered by a layer comprising zones of dielectric material and zones of electrochromic material, without any free space between these zones.