Solderability of conventional Sn-37Pb solder pastes and Pb- free alloys (Sn-43Bi and Sn-2Ag-5Bi-0.5Cu) were examined on micro soldering using a YAG laser. Experiments were performed in order to determine the range of soldering parameters of a laser power density and an irradiation time for obtaining an appropriate wettability based on a visual inspection by a Japanese Industrial Standard. And the laser soldering processes were monitored by measuring temperature change inside solder joint (solder and Cu pad) and on a surface of a chip component. Next joining strength of chip components for surface mounting soldered on printed circuit board (glass epoxy) was tested on application thickness of solder paste (0.2, 0.3, and 0.4 mm). In addition, joining strength characteristics at different power density and materials were examined around thermal shock test by the gas phase method. As a result, characteristics of Sn-Ag-Bi-Cu (Pb-free) solder paste are equivalent to that of Sn-Pb solder paste.