PURPOSE: To increase a surge current resistance quantity by alternately arranging a plurality of first conductive diffusing layer regions inside second conductive diffusing layer regions disposed at both surfaces of a first conductive semiconductor substrate, respectively, and connecting electrodes to the diffusing layer regions at both the surfaces.
CONSTITUTION: Normal direction thyristors 11, 12, 13 of a pnpn-structure constituting of a p-type diffusing layer region 3a, an n-type diffusing layer region 2a, a p-type semiconductor substrate 1 and an n-type diffusing layer region 2b and reverse direction thyristors 14, 15, 16 of a pnpn-structure constituting of a p-type region 3b, an n-type region 2b, a p-type substrate 1 and an (n) region 2a are arranged alternately. Application of a positive lightning surge to an electrode 7a enables the thyristors 11, 12, 13 and a heat generating source to be diffused. A heat generating portion inside an element is diffused, a peak temperature at the time of application of the lightning surge is reduced, and a temperature distribution is uniformed rapidly, thus increasing a surge current resistance quantity and enhancing reliability.
WADA TSUTOMU
SHIMODA YOSHIO
| JPS5562768A | 1980-05-12 | |||
| JPH01171273A | 1989-07-06 |