Embedding electronic circuits by laser direct-write

Significant reduction in weight and volume for a given circuit design can be obtained by embedding the required passive devices, semiconductor IC's and interconnects into the circuit board. In addition, embedded structures allow for improved electrical performance and enhanced function integration within traditional circuit board substrates and non-traditional surfaces. Laser-based direct-write (LDW) techniques can be used for developing such embedded structures at a fraction of the cost and in less time than it would take to develop system-on-chip alternatives. In this work, subtractive LDW in the form of laser micromachining is used to machine vias and trenches on polymer resin circuit board substrates, while additive LDW in the form of laser forward transfer, or laser printing, is used to deposit patterns of electrically conductive materials. The combination of these laser direct-write techniques resulted in the fabrication of a fully operational planar embedded electronic circuit. This embedded prototype occupies only a fraction of the volume required by the equivalent circuit fabricated on top of a printed circuit board using traditional manufacturing processes. Published by Elsevier B.V.