Published online by Cambridge University Press: 15 February 2011
We have developed a new two-step process to generate a metallic pattern on dielectric materials. This method employs ultraviolet (uv) laser irradiation followed by electroless deposition. A few laser pulses are required to generate the pattern. After immersion in an electroless bath, the metal film is deposited only on the uv exposed area. Results of the application of this method to aluminum nitride and alumina are presented. The laser irradiation step is very fast, and the electroless deposition is simplified because it does not require any special seeding to promote activation, i.e. laser irradiation activates the dielectric surface for electroless deposition. In addition, the laser-induced activation of the insulator is maintained for a very long time allowing electroless deposition to be performed many months after irradiation. Patterns in the tens of microns can be produced on laser-exposed substrates. Pull tests have been performed to determine the bond strength. We have found that the bond strength can be further increased by annealing.