A new family of liquid toners has been developed to print conductive traces on printed circuit boards by a digital printing technology. The new toners are based on Parmod™ technology which has been developed to enable low cost production of printed circuits by a simple print-and-heat process. The novel feature of these printable materials is that they cure to pure metallic conductors in seconds at a temperature low enough to be compatible with polymer-based printed circuit substrates. The resulting circuit traces have high electrical conductivity and are solderable. The use of conventional printed circuit substrates and the speed of the process permit high-production, low-cost roll to roll processing.The extension of Parmod™ technology to liquid toners provides two major additional benefits: 1) It provides a major increase in resolution for production of advanced technology high density interconnect structures, and 2) It permits direct digital printing of circuits from CAD files with no intermediate tooling requirements. The latter capability realizes the goal of total CAD/CAM integration and the ultimate in manufacturing flexibility. This paper discusses the characteristics of Parmod™ technology, the performance of the liquid toners based on it and some applications of the technology which can be foreseen.
Paul H. Kydd, David L. Richard, Robert H. Detig, "Electrostatic Printing of Parmod™ Electrical Conductors" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP14), 1998, pp 222 - 225, https://doi.org/10.2352/ISSN.2169-4451.1998.14.1.art00055_1