Screen-printing screen and process for obtaining glazings equipped with electrically conductive patterns

A process for obtaining a glazing coated on one of its faces with electrically conductive patterns located in at least one lateral portion and in a central portion of the glazing, said electrically conductive patterns comprising electrically conductive tracks of thickness e1 located in the or each lateral portion and electrically conductive tracks of thickness e2 located in the central portion, the thickness e1 being larger than the thickness e2, said patterns furthermore comprising, in the central portion, at least one thick electrically conductive pattern, said process comprising screen printing said electrically conductive patterns in a single pass, by way of the following steps:

• positioning a screen-printing screen facing a glass sheet, the screen-printing screen including a main mask possessing a central portion and at least one lateral portion, an aperture size of the main mask being larger in said at least one lateral portion than in said central portion, said screen screen-printing furthermore including, in at least one zone located in said central portion, at least one secondary mask fastened to a face of said main mask, said at least one zone forming a double-mask zone, an aperture size of the or each secondary mask being larger than the aperture size of the main mask in said central portion, a mesh of the main mask extending in a first direction in a surface of said main mask and a mesh of the at least one secondary mask extending in a second direction in a surface of said at least one secondary mask, said first direction making with said second direction an angle α comprised between 1 and 89°, said screen-printing screen being placed so that the central and lateral portions and of the screen-printing screen are in correspondence with the portions of the glass sheet that are intended to become the central and lateral portions of the glazing, respectively, and so that the or each double-mask zone is in correspondence with a zone of the glass sheet that is intended to be coated with a thick electrically conductive pattern;
• then
• depositing an electrically conductive paste on the screen-printing screen.