| 摘要 |
<p>PURPOSE:To obtain a device which attaches no polarity to varistor voltage and produces no changes in insulation resistance by forming semiconductor ceramics in cylindrical shape and, what is more, defining the cylindrical shape of the semiconductor device in such a fashion that one terminal section of the cylinder may be larger-sized than the other terminal section. CONSTITUTION:A cylindrical shape 13 is formed with semiconductor ceramics mainly composed of SrTiO2 and having voltage dependent non linear resistant characteristics. One terminal section 10 of the cylinder 13 is larger-sized than the other terminal section 9 and formed in cylindrical shape as well. The length of the larger-sized cylinder 10 is made shorter than that of the other portion 9. In the central part of the cylinder 13 is formed a penetration hole. An inner peripheral electrode 11 is formed on the whole inner peripheral surface of the cylinder 13, thereby forming an outer peripheral electrode 12 on the whole outer peripheral surface of the small-sized portion of the cylinder 13 and on a doughnut-shaped plane in contact with the small-sized cylindrical portion 9 on the larger-sized cylinder 10. It is also acceptable to replace a part of main component Sr of the semiconductor ceramics with one element and more, such as Ca, Ba and Mg. This construction makes it possible to stabilize the electric properties and obtain high reliability devices as well.</p> |
