| 摘要 |
PROBLEM TO BE SOLVED: To improve solder resistance of an electrode part, enable direct mounting on a wiring board surface, and realize miniaturization, by wrapping a first metal layer with a second metal layer of high solder erosion resistance, and covering the side surface of the first metal layer with the second metal layer. SOLUTION: In a first metal layer 22, a positive electrode part and a negative electrode part formed on both end surfaces of a chip which are parallel to a P-N junction part and face each other constitute ohmic electrodes. A second metal layer 23 is more hardly eroded by solder under the mounting condition than the first metal layer, and comparatively excellent in solder wettability. The region where the second metal layer 23 is formed covers the side surface of the first metal layer 22 so as to protect it. Thereby direct mounting on a wiring board by soldering is enabled, so that the size of a light emitting and receiving element can be reduced to the dimension of a chip and thinned. Further wire bonding and resin molding in the conventional case are made unnecessary, so that cost reduction is realized. |
