Patent ID: 8263293

Claim:
A photolithographic process for producing tridimensional structures in a structural layer in photopolymer for an ink jet printhead, said tridimensional structures being made on a substrate having a bottom wall at least in part reflecting, and comprising at least a side wall adjacent to said bottom wall, said process comprising: depositing on said substrate a photopolymerizable layer comprising a solution of a monomer or oligomer, a photoinitiator, and a polymerization inhibitor basic compound in a quantity less than the stoichiometric value corresponding to the complete neutralization of the acid species generated by the photoinitiator; masking said layer for defining areas protected by said masking and areas not protected by said masking, intended to make said tridimensional structures; irradiating with an ultraviolet (UV) radiation for generating acid species suitable for promoting the polymerization of said solution in said areas not protected by said masking; in which a fraction of said radiation is reflected by said reflecting part on the inside of said areas protected by the masking, unwanted acid species being generated in a quantity corresponding to said fraction of radiation, on account of said reflected radiation; neutralizing said unwanted acid species by means of said inhibitor basic compound; removing said unpolymerized photopolymerizable solution from said areas protected by said masking.