and then heating the substrate and uncured polyimide oligomers to a curing temperature causing cross linking of the polyimide oligomers into a polyimide resin in fig3 b a heated probe tip 210 is pushed down perpendicular to a top surface 215 of substrate 200 into cured polyimide resin layer 205 and then dragged parallel to top surface 215 of substrate 200 thus exposing a region of substrate 200 in fig3 c a trench 220 is etched into substrate 200 wherever the substrate is not protected by cured polyimide resin layer 205 in fig3 d cured polyimide resin layer 205 see fig3 c is removed fig4 a through 4e are cross section views illustrating formation of a pattern in a substrate according to another embodiment of the present invention fig4 a are 4 b are similar to fig3 a and 3b except in fig4 b heated probe 210 is not pressed completely through cured polyimide resin layer 205 forming a cured polyimide resin thinned region 225 in cured polyimide resin layer 205 in fig4 c cured polyimide resin thinned region 225 see fig4 b is removed exposing top surface 215 of substrate 200 and also producing a thinned cured polyimide resin layer 205 a in one example the removal of cured polyimide resin thinned region 225 is done by reactive plasma in one example the removal of cured polyimide resin thinned region 225 is done by controlled exposure to a liquid or a vapor in fig4 d trench 220 is etched into substrate 200 wherever the substrate is not protected by thinned cured polyimide resin layer 205 a in fig4 e thinned cured polyimide resin layer 205 a.