Micro-jet printing of polymers and solder for electronics manufacturing

Ink-jet/micro-jet printing methods are being developed for direct writing of a variety of materials for electronics and optoelectronics manufacturing. The advantages offered by this approach for microelement fabrication and adhesive joining include precise volumetric control of dispensed material, data-driven flexibility, low cost, high speed, and low environmental impact. Custom thermo-setting and thermoplastic systems have been developed for the printing of optical interconnects, dielectric elements and coatings, adhesives and thick film resistors, utilizing a drop-on-demand piezoelectric print head operable at temperatures up to 300 degrees C. Reviewed here are examples of printing of (a) adhesives for component bonding; (b) dielectrics for overcoating and conformal microelectronics fabrication; (c) thick-film resistors; (d) micro-optical components; (e) polymers filled with oxides and fluorescing materials and (f) solder bumps, Manufacturing applications potentially addressable to advantage by this method include flip chip die attach, chip-scale microelectronics packaging, underfilling and overcoating, along with fabrication of passive devices, disk drive heads, and flat panel displays.