LIQUID COMPOSITION

A liquid composition includes copper particles, an organic acid, and a solvent. The copper particle has a particle size of 0.5 μm˜30 μm which falls in a micron scale. The liquid composition performs reaction sintering by redox reactions taken place between the copper particles and an organic acid solution at a low temperature of 150° C. in order to produce a dense copper layer and improve the conventional micron-scale copper particles that requires a protective atmosphere for the high-temperature sintering before achieving the required densification. This liquid composition also prevents an excessive oxidation of the nano copper particles during the low-temperature sintering process and a failure of the dense sintering. Due to the agglomeration of nano copper particles, some areas have to be sintered first, so that the sintered products have a good uniformity of tissue and a low resistance below 0.04 ohm per square (Ω/□).