Abstract:
A low-capacitance multilayer chip varistor has capacitance lower than 0.5 pF at 1 MHz and has a characteristic of resisting more than thousands of times of 8 KV electrostatic shock, which comprises a ceramic main body, outer electrodes disposed at two ends of the ceramic main body and inner electrodes disposed therein; the ceramic main body comprises inorganic glass of 3˜50 wt % and semi-conductive or conductive particles of 50˜97 wt % with particle size of more than 0.1 μm, and a layer of inorganic glass film covers the surface of semi-conductive or conductive particles, wherein the inorganic glass film contains semi-conductive or conductive particles of submicron or nanometer which is smaller than 1 micron, and the quantity contained of semi-conductive or conductive particles is less than 20 wt % of that of inorganic glass.
Abstract:
A multilayer ceramic device comprises a laminated ceramic body having opposite end surfaces, a pair of conductive electrodes each respectively attached to one end surface of the laminated ceramic body and a plurality of alternately staggered internal electrodes within the laminated ceramic body configured in an alternating manner and each electrically connected to the corresponding conductive electrodes respectively; each conductive electrodes of the multilayer ceramic device is further covered with a solder paste layer so that the multilayer ceramic device is thus made without any plating step and no need of treating waste liquid nickel or waste liquid tin as well as no problem of environmental pollution caused by plating solution, thereby lowering manufacturing costs and reducing processing time.
Abstract:
A low-temperature firing process is available for cost saving to produce a multilayer chip ZnO varistor containing pure silver (Ag) formed as internal electrodes and calcined at ultralow firing temperature of 850-900° C., which process comprises: a) individually preparing ZnO grains in advance doped with doping ions for promotion of semi-conductivity of ZnO grains if calcined; b) individually preparing a desired high-impedance sintering material to be fired as grain boundaries to encapsulate ZnO grains; c) mixing the doped ZnO grains of Step a) with the high-impedance sintering material of Step b) in a predetermined ratio to form a mixture and proceeding with an initial sintering to have the mixture sintered and ground as composite ZnO ceramic powders, and d) processing the sintered mixture of Step c) to make multilayer chip ZnO varistors containing pure silver (Ag) internal electrodes but sintered at ultralow firing temperature of 850-900° C.