PHOTOCOUPLER

PROBLEM TO BE SOLVED: To make it possible to satisfy the rated reinforced insulation, which responds to the output of a high voltage at a standard value, of an instrument, specially the rated creeping distance, without widening the installation area of a package by a method wherein the creeping distance, which is constituted in the package, is made long without changing the intervals between electrode leads, which are provided in opposition to each other. SOLUTION: The shape of a package 1 is swelled to the left and right sides into a trapezoid shape without changing the dimension of an installation width (g), whereby a creeping distance "A, which is shown by the dotted lines, is made long. Or the shape of the package 1 is formed into a waved shape, whereby the creeping distance *is made long without changing the dimension of the installation width (g). Or even in the form of the package 1 in the case where the vicinities only of the end parts of the package 1 are formed into a waved shape, the creeping distance * can be made long without changing the dimension of the installation width (g). As a result, it is made possible that the mounting area of an IC is made narrow as small as possible and the external creeping distances of primary side leads 2 and secondary side leads 2 are made long to correspond to the rated reinforced insulation of an instrument.