High precision solder droplet printing technology: principle and applications

Solder droplet printing technology, which is low-cost, noncontact, flexible, data-driven, and environmentally friendly, has emerged as an enabling technology for precisely placing fine solder deposits on a variety of small substrates. It is suitable for a variety of applications including direct chip attach site preparation, 3D substrates, fine line interconnect, substrate via fill, optoelectronics and many others. It enables manufacturing techniques that are impossible or unfeasible with current technology, such as localized replacement of solder on board, depositing solder in different thicknesses on the same board, or using more than one type of solder on the same board. This makes the evaluation of solder droplet printing technology essential for the microelectronics industry. In this paper, the principle of the solder droplet printing technology is described, recent experimental results are included, and potential applications of the technology in the microelectronics industry are evaluated.