| 摘要 |
<p>PURPOSE:To obtain an element which as a good soldering property and a superior resistance to beat in soldering by a method wherein a doughnut-form electrode having the same inner diameter as a through-hole is formed on one end plane of a semiconductor ceramic cylinder is formed and it is united into one body with an electrode of an inner circumferential plane of the hole and counter electrode is arranged on an outer circumferential plane on another end plane side at a distance from the end plane, so that a varistor voltage does not change even if a part of solder flows into a gap between a pin and an element. CONSTITUTION:On one end plane of a cylindrical sintered body composed of SrCo3, CaCo3, BaCO3, MgCO3 and TiO2, a doughnut-form electrode whose diameter is smaller than an outer diameter of a cylinder and whose inner diameter is the same as a through-hole is formed by using a conductive paste, and an electrode is arranged on an inner circumferential plane of the hole and these electrodes are united into one body to from a fundamental elec trode 1. On another end plane side of the cylinder, a counter electrode is arranged to form a fundamental electrode 3, followed by sintering. Next, on these fundamental electrodes 1 and 3, surface electrodes 2 and 4 composed of a triple-layer structure of Cu-plating/Ni-plat- ing/solder plating are formed by a non-electrolytic activating plating, thereby obtaining an element 5. The electrical characteristics are stable and a varistor voltage has no polarity, so that a change in the characteristics between before and after an assembly is extremely small and the characteristics are stable.</p> |
