Abstract: A resin-based VOC-free soldering flux consists of 40 to 50 wt % of a liquid epoxy resin, 25 to 30 wt % of a non-volatile liquid epoxy diluent, 20 to 33 wt % of a polyfunctional carboxylic acid, and 2.0 to 3.5 wt % of a thixotropic agent. There are no volatile organic solvents or compounds in the flux which can evaporate during the reflow process. The carboxylic acids are provided in powdered form and are suspended in the epoxy blend wherein they remain as solid particles until heated in the solder reflow process. A VOC-free solder paste formed from the flux consists of 40 to 95 wt % soldering particles, and 5 to 60 wt % of the VOC-free soldering flux. The thixotropic agent improves printability of the solder paste onto printed wiring boards. A VOC-free flux-core solder wire includes the VOC-free flux as the inner core of the wire with an outer shell of solder alloy.

Abstract: A solder preform comprises a body of solder material having at least three legs extending outwardly from a generally central base portion. In a method of use, the preform is disposed between two solderable surfaces (such as the metalized undersurface of a semiconductor die and a support surface therefor), heated above the solder melting point to cause the solder to flow between the surfaces, and then cooled to solidify the solder and effect the bond. The preform configuration is such that the melting solder flows generally outward from the central base portion to expel gases from between the surfaces to be bonded.

Abstract: A solder alloy which is particularly effective for use in automotive radiator applications comprises 87.5%-96.5% lead, 3%-10% tin, 0.5%-2.0% antimony, and 0-0.5% silver. The solder has high mechanical strength, is resistant to galvanic corrosion, and is readily solderable.