| 摘要 |
PURPOSE:To obtain a switch which is turned ON-OFF being bounded at a fixed temperature and can be switched ON-OFF even by a DC power source by juxtaposing horizontal npnpn5 layer structure and vertical pnpnSCR structure. CONSTITUTION:In a horizontal SCRA, n layers 10 and a p layer 4 are made high concentrations, p layers 8 are made low concentrations, and the leakage currents of a junction 9 are increased by low-life regions 23. When applying a DC power source 25 among cathodes 19 and an anode 20, the SCRA is turned ON when not less than yield voltage of a junction 7. A vertical SCRB is a heat sensitive SCR which is changed into OFF from ON when not less than a fixed temperature, and connects electrodes 21 and 20. The SCRA stably keepts its ON within a temperature range in which the yield voltage VBO of the SCRB is larger than the sum VS of the voltage drops of the junction 7 and a junction 5 of the SCRA. When a temperature rises and the VS exceeds the VBO, the SCRB is turned ON and the SCRA OFF. When a temperature drops, the SCRB and the SCRA are restored to the original states. The less gate resistance 26 is made the more the SCRB and the SCRA shift to OFF from ON at a high temperature. According to this constitution, a heat sensitive switch is obtained which can be switched ON-OFF even using the DC power source. |
