Patent ID: 7275817

Claim:
Process for forming a fluid inlet wafer for a microfluidic device, said wafer having a fluid particle-filter layer over the discontinuous fluid-inlet surface thereof comprising the steps of applying a thin coating of a heat-curable, photopatternable polymer composition to an intermediate substrate having a release surface; drying said coating to form a semi-solid adhesive layer; pressing said layer and supporting substrate against the discontinuous fluid-inlet surface of a fluid inlet wafer and optionally an additional adhesive layer to bond said layer to said discontinuous fluid inlet surface; separating said substrate to transfer the contacting area of said semi-solid layer to said discontinuous fluid-inlet surface as a laminate without any penetration into the fluid inlet passages thereof, photoexposing said semi-solid layer, through a filter-forming mask and developing fluid particle-filter openings therethrough, either before or after transfer of said semi-solid adhesive layer from said intermediate substrate to said discontinuous fluid-inlet surface of said fluid inlet wafer, and heat curing said filter layer so that the filter layer is a monolithic layer in contact with the discontinuous fluid-inlet surface of the wafer.