Towards Miniaturization of Electronics by Developing and Characterizing Hyperfine Solder Powders used in Printed Circuit Boards

Today's electronics industry, due its continues growth and increasing demand for devices such as cell phones, satellite navigation systems, health devices, etc., faces important challenges related to the vast quantity of raw materials needed for sustainability and the quantity of waste generated from electronics equipment. To sustain its growth, the electronics industry needs innovations, such as the miniaturization of printed circuit boards (PCB) for increasing components density. Consequent development of miniaturized electronics design plays, therefore, a key role for the reduction of energy consumption and raw materials sustainable use. A factor, however, that currently limits this endeavor is the availability of hyperfine pitch solder powder pastes. The present work focuses on the development of novel, low cost, type 8 & 9 solder pastes with hyperfine solder particles (with size distribution of 1-10 mu m) aiming at printing PCBs with increased component density. The solder joint quality was characterized using nondestructive techniques after manufacturing at different reflow parameters. Infrared thermography and white light interference microscopy provided information on internal defects such as presence of micro-voids, as well as on the topography of geometrical variations of solderbals, solder errors, and warpage of components, which are related to the thermal history of the component during reflow.