a polymer - based solder paste composition having the strength and corrosion resistance of joints produced by conventional solder technology and the environmental and processing advantages of ica technology comprises a powdered solder metal with a single component polymerizable flux composition . the polymerizable flux composition includes 55 %- 65 % by weight of an epoxy such as epoxy novolac , the diglycidyl ethers of bisphenol a and f , and mixtures thereof , 0 - 15 % by weight of a dicarboxylic acid , 9 %- 11 % by weight of a polyalcohol , 3 %- 5 % by weight of an amine thermal curing agent , and the balance including a chelating agent , a defoamer , a thixotrope and a surfactant . upon heating , the solder metal spontaneously segregates from the flux composition , fuses , and forms a metallurgical joint , while the single - component polymerizable flux composition encapsulates the fused metal in a polymer coating which remains firm but pliable at reflow temperatures .