BONDING MATERIAL AND BONDING METHOD OF ELECTRIC ELEMENT

摘要

PURPOSE: To join a semiconductor element to a pedestral with a sufficient adhesion and a stable electric connection. CONSTITUTION: An Ni layer 10 and an Au-Sn solder layer 11 are formed on an N-type electrode 9 as the ohmic electrode of a semiconductor laser element. The solder layer 11 is fused and bonded to a heat sink 21 plated with gold 21a. The thickness of the Ni layer 10 is 500Å or greater. At the time of fusion of the solder layer 11, Ni in the Ni layer 10 diffuses in the solder layer 11, and Sn in the solder layer 11 diffuses in the Ni layer 10. As the result of mutual diffusion, the adhesion and the wettability can be improved. The composition ratio of the Ni layer 10 is set higher than or equal to 1.3wt.% and lower than 10wt.% to the Au-Sn solder layer 11. Thereby bonding is enabled at a low melting point and high bonding strength can be obtained.