A method of forming electrically conductive elements on a base layer of an
electronic substrate without the use of solder mask. A layer of
electrically conductive material is deposited on the base layer, and a
first layer of photo imageable ink is applied over the electrically
conductive material layer. The first layer of photo imageable ink is
patterned to expose portions of the electrically conductive material
layer, which are then etched to resolve traces in the electrically
conductive material layer. The first layer of photo imageable ink is
removed, and a second layer of photo imageable ink is applied over the
traces and channels between the traces. The second layer of photo
imageable ink is then patterned to expose the traces, and a third layer of
photo imageable ink is applied over the traces and the second layer of
photo imageable ink. The third layer of photo imageable ink is patterned
to expose deposition sites on the traces, within which are formed
electrically conductive fingers. Both the second layer and the third layer
of photo imageable ink are retained on the electronic substrate.
