METHOD FOR PRODUCING A CONCEALED IMAGE ON PHOTORESIST FILM AND DEVICE FOR REALIZATION OF THE METHOD Russian patent published in 2008 - IPC H05K3/00 

FIELD: electronics, in particular, production of electronic boards.

SUBSTANCE: in accordance to the invention, as an air space under photoresist, for example, apertures on electronic board template, covered in photoresist, may be considered, and also previously produced photoresist pattern, covered again by photoresist. For air space under photoresist to become photo-template, before writing of photoresist during heating of photoresist with infrared radiation, ratios of current densities above one are tracked, where currents flow through two identical dielectric gaps between conductors, which are electrically bridged by photoresist without air and with air below it. Photoresist is written during its heating by ultraviolet component in the spectrum of infrared radiation until the end of process of photo-inhibition of photoresist thickness by oxygen in the air. Completion of photo-inhibition is monitored on basis of reduction of density value of current which passes through dielectric gap between two conductors, which are electrically bridged by photoresist with air below it, where value of current density reduction is used to control the value of the gap between the edge of air space below photoresist and the edge of concealed image being created during continuation of writing of photoresist with ultraviolet radiation.

EFFECT: expanded resources of existing technologies due to usage of air space below photoresist instead of a photo-template with adjustable geometry during writing of photoresist, due to presence of oxygen in the air which is an inhibitor of photo-polymerization.

2 cl, 4 dwg