Lockheed Martin Corporation
Methods of soldering and applications thereof

Abstract:

The present disclosure describes methods of soldering on printed circuits, and, more specifically, to methods of using a copper-containing layer or copper "ink" in low-temperature soldering using established solder processes on silver-containing layers in circuit boards. The present disclosure is also directed, in part, to a solder joint having a copper-containing layer acting as a bonding layer between a traditional solder and a silver-containing layer "ink" on a printed circuit board. The low-temperature forming of the solder joint occurs at or below a temperature of 300.degree. C. and occurs via at least one of sintering, photosintering, lasersintering, local resistive heating, or electrochemical deposition. The methods disclosed can satisfy the growing demand for creating reliable interconnection joints that can be used in next generation electronics and printed electrical circuit boards.