126results about "Thick film varistors" patented technology

A light emitting device has a semiconductor light emitting element and a multilayer chip varistor. The multilayer chip varistor has a multilayer body with a varistor portion therein, and a plurality of external electrodes disposed on an outer surface of the multilayer body. The varistor portion has a varistor layer containing ZnO as a principal component and exhibiting nonlinear voltage-current characteristics, and a plurality of internal electrodes arranged to interpose the varistor layer between them. Each of the external electrodes is connected to a corresponding internal electrode out of the plurality of internal electrodes. The semiconductor light emitting element is disposed on the multilayer chip varistor. The semiconductor light emitting element is connected to corresponding external electrodes out of the plurality of external electrodes so as to be connected in parallel to the varistor portion.

An object of the present invention is to provide a multilayer filter constructed so as to be less likely to suffer peeling between a varistor part and an inductor part. A multilayer filter 10 as a preferred embodiment has a structure in which a varistor part 20 and an inductor part are stacked. The varistor part 30 consists of a stack of varistor layers 31, 32 with internal electrodes 31a, 32a, and the varistor layers contain ZnO as a principal component, and contain at least one element selected from the group consisting of Pr and Bi, Co, and Al as additives. The inductor part 20 consists of a stack of inductor layers 21-24 with conductor patterns 21a-24a, and the inductor layers contain ZnO as a principal component and substantially contain neither Co nor Al.

An electronic protection component incorporates both a varistor and an alloy-type thermal fuse. In one embodiment, a melting promoting agent or flux contacts and surrounds both the varistor and the fuse in common in a shared cavity of a case. In another embodiment, the fuse and the flux are disposed in an inner case, which is disposed in contact with the varistor in an outer case. Thus, the varistor and the thermal fuse are incorporated so that the speed of heat transfer is fast, the response time is fast, and the installation for use is convenient.

A varistor comprises a varistor portion, a metal portion, and buffer portion. The varistor portion has a varistor element body exhibiting a nonlinear current-voltage characteristic and two electrode portions. The metal portion has a thermal conductivity higher than that of the varistor element body. The buffer portion is disposed between the varistor portion and metal portion so as to be bonded to each of the varistor portion and metal portion and mainly composed of glass. The two electrode portions are arranged in the varistor element body so as to be electrically insulated from each other while exposing at least a portion of each thereof from an outer surface of the varistor element body. The metal portion and varistor portion are joined firmly to each other. The heat transmitted to the varistor can efficiently be diffused from the metal portion.

A resistance memory element is provided which has a relatively high switching voltage and whose resistance can be changed at a relatively high rate. The resistance memory element includes an elementary body and a pair of electrodes opposing each other with at least part of the elementary body therebetween. The elementary body is made of a semiconductor ceramic expressed by a formula: {(Sr1-xMx)1-yAy}(Ti1-zBz)O3 (wherein M represents at least one of Ba and Ca, A represents at least one element selected from the group consisting of Y and rare earth elements, and B represents at least one of Nb and Ta), and satisfies 0<x≦0.5 and 0.001≦y+z≦0.02 (where 0≦y≦0.02 and 0≦z≦0.02); 0.5<x≦0.8 and 0.003≦y+z≦0.02 (where 0≦y≦0.02 and 0≦z≦0.02); or 0.8<x≦1.0 and 0.005≦y+z≦0.01 (where 0≦y≦0.02 and 0≦z≦0.02).

A multilayer chip varistor comprises a multilayer body in which a plurality of varistor portions are arranged along a predetermined direction, and a plurality of terminal electrodes. Each varistor portion has a varistor layer to exhibit nonlinear voltage-current characteristics, and a plurality of internal electrodes disposed so as to interpose the varistor layer between them. Each terminal electrode is disposed on a first outer surface parallel to the predetermined direction out of outer surfaces of the multilayer body and is electrically connected to a corresponding internal electrode out of the plurality of internal electrodes. Each of the plurality of internal electrodes includes a first electrode portion overlapping with another first electrode portion between adjacent internal electrodes out of the plurality of internal electrodes, and a second electrode portion led from the first electrode portion so as to be exposed in the first outer surface. The plurality of terminal electrodes are electrically connected via the respective second electrode portions to the corresponding internal electrodes.

In a varistor, a heat radiating portion contains the same components as ZnO that is the main component of a varistor element body, as metal oxides, thereby, the structural components of the varistor element body and the heat radiating portion are caused to be common. During firing, Ag contained in the heat radiating portion diffuses into the grain boundaries of ZnO, near the interface between surfaces of the heat radiating portion and the varistor element body. Consequently, in the varistor, cracks hardly occur between the varistor portion and the heat radiating portion during firing (or during binder removal), thereby, ensuring sufficient bonding strength between the varistor portion and the heat radiating portion. Therefore, heat conducted to the varistor portion is radiated efficiently conducting through electrically conducted paths formed in the heat radiating portion from the surface facing the varistor element body to other three surfaces of the heat radiating portion.