Method for pressing a material into a through-hole or blind-hole in a substrate. The material is disposed on the surface of the substrate. An environment is provided permitting the material to flow for example by heating the material to the glass transition temperature or above. Thereafter pressure is applied causing the material to flow, first coating the sidewall of the hole and on the continued application of pressure the material flows to completely fill the hole. The resulting substrate can have a substantially planar surface having holes with the periphery coated with or completely filled with the material. The material is preferably a thermoplastic polymeric material such as a polyimide and a perfluorinated polymer.