Research progress of laser direct writing technologies for the conductive metallic wire on dielectric surface

Fabrication of conductive metallic wire on dielectric surface has a broad application in microelectronics, optoelectronics, electromechanical systems, etc. As a very promising alternative, laser direct writing is a maskless, efficient, and flexible approach that readily allows for free-form writing of a wide range of conductive metallic patterns on substrates, and hence has attracted an enormous amount of attention in the past several years. Laser direct writing can be achieved via photochemical or photothermal process, including photochemical reduction of metal ions, laser induced forward transfer, laser heating reduction of metal ions, etc. Herein, the laser direct writing strategies for fabrication of conductive metallic wires including the principle, characteristics and research progress have been reviewed in detail. Furthermore, remaining challenges and development trends are summarized and prospected.