Method of Producing Advanced Printed Wiring Boards Using the Technology of Thermal Spraying

The technology of thermal spraying will be used as the basis for developing a novel process of producing printed wiring boards. Thermal spraying of copper onto engineered plastic substrates that have been masked to expose a wiring pattern will be demonstrated as an efficient and environmentally friendly method to produce printed wiring boards. Several masking techniques along with different spray deposition processes, including a new process known as "Cold Spray" will be evaluated to determine the most promising methods of producing printed wiring boards. The use of thermal spray technology should eliminate almost all of the chemical processes currently required with state-of-the-art plating baths. Reduction or elimination of these chemicals will consequently reduce the use of rinse waters and eliminate the disposal of solid wastes from the various plating and etching processes currently used. The copper overspray generated from the thermal spray process can be easily captured and recycled. Another significant potential advantage of spray deposition processing is a significant reduction in processing time. A conventional circuit board requires approximately 18 hours of processing time. The same board produced with the thermal spraying process should take less than two hours to manufacture. This reduction in processing time should decrease processing costs.