Once The Solid Phase Method Of Ptc Motor Starter Ceramic Chip Research

With the development of complete electrical apparatus, the need of electrical components with long life, high reliability, high stability, environmental friendly and low price is becoming even more intense. The preparation of electrical functional materials has a long time process with relatively high energy consumption, high pollution and easily bring in impurities during manufacture which will cause the reduction of electrical property. Research on how to reduce traditional technical preparation section, detrimental impurity, energy consumption and producing cost, and how to achieve high quality electrical components finally are an universal subject.The main work of this paper is to solve the compactness and blistering problems during the researches on preparation technology and organization of Positive Temperature Coefficient (PTC) ceramic chip used on motor starter with the method of solid phase synthesis once. At the same time, we compare the superiorities and deficiencies between solid phase synthesis once and solid phase synthesis twice. Finally we determine the structure property of samples with laser particle analyzer, PTC'R-T'performance test system, RTCR synthetic parameter tester, RTCR withstand voltage tester and scanning electron microscope (SEM).Firstly, we grind the original powder lot with ball grinding mill , analyze the influence of ball-milling time on the performance of power lot by laser particle analyzer,and determine the optimum ball-milling time by comparing the relation between different ball-milling time and physical dimension and the relation between physical dimension and performance of powder at last.Secondly, we have been finished the research of pelletizing and molding technologies to make sure that the compactness of the ceramic clay body is well-behaved and the fatal defects of ceramic clay body are eliminated, such as blistering and delaminating and so on.Finally, the work of BaTiO₃ powder with high purity electron level doped by multiple-donor doping of Y₂O₃ and Nb₂O₅ directly at the optimal parameter condition have been finished. Doped donor replacing position of Ba2+ or Ti4+ directly makes BaTiO₃ form a cavity or an electron and have good PTC semiconductor characteristic. Curie temperature of product can reach to 133.4℃at the condition of no PbO.This subjects use solid phase synthesis once method, multiple-donor doping and ball-milling once to reduce traditional manufacture process (no need to burn-in, prepress, and ball-milling twice) and at the same time reduce the doping of harmful impurities, and to increase the product percent of pass. We produce the Positive Temperature Coefficient (PTC) ceramic chip apply to motor starter successfully.