By Rick Larson
Photonic soldering is a process where high intensity light from a flash lamp is used as an energy source to uniformly heat up a large, exposed area. This process offers the ability to mask components, use of differences in absorption, changes in input power and variation of exposure duration over a few seconds to preferentially heat up specific areas of a working device. This technology enables quick and concurrent re-attach of multiple passives without affecting the other parts of the board.
High powered flash lamps are digitally controlled to create a nonequilibrium soldering step, leading to wide range of substrate, materials and component selection. This technique enables the use of temperature sensitive substrates with conventional higher temperature solder alloys. This presentation introduces the novel soldering technique, discuss the advantages, provides an overview of the resulting solder joints and discusses the application space for this technology.