We have examined laser sintering conditions for minute wiring using Ag NanoPaste^[○!R], and evaluated sintering characteristics. First, line patterns were drawn on a Cu substrate by ink-jet printing with the paste: about 80μm in width and about 2μm in thickness. Then, the specimen was dried at 443K for 20min to anchor the paste. Laser sintering of the dried pattern was carried out twice in a row by scanning a beam at average laser powers of 1.99W and 4.45W in air, where a pulsed Nd: YAG laser of 1.06μm wavelength and 0.1mm spot diameter was used. As a result, the Ag nano particles (5nm in average diameter) dispersed in the paste are welded to form coarse agglomerate of about 0.4μm. Adhesion strength between the sintered wire and the substrate was evaluated by a bend-peel test. No separation occurs, which means that strong wiring is achieved by the proposed method.
