The Research Of PTCR Magnetron Sputtering Electrode And Properties

The PTCR based on BaTiO3 semiconducting ceramic materials were used widely in communication, household electrical appliances, automobiles and spaceflights. Electroless nickel-plating and fired Al were in common use. The former was harmful to the environments, and the latter had many disadvantages of techniques difficult to be mastered and poor properties in moist-hot environments. In this dissertation, DC magnetron sputtering and nickel chromium alloy (Ni80%Cr20%) as target material were employed to make bottom electrode on PTCR components. The thickness of the electrode we got was approximately 1.0μm, and good ohmic contacts was formed between the electrode and the ceramics.We got favorable electrode without heat treat according to the process condition,which sputtering power was 2.0~3.0 KW, Ar pressure was 8.7~9.3×10-2Pa, deposition time was 5~12 mins. It was found that the change of sputtering power influenced the properties of PTC moto-start components most in the technique parameters range as the preamble gave. The technique parameters were optimized to get the least invalidation probability of PTC components and it could be seen from the SEM images that the films made in the optimum technique parameters had less holes, better densification character and less mutual diffuse between boundries.By comparing the electrical characteristics of PTC moto-start components made in different technics and target materials we found that the components which used sputtering nickel chromium alloy eletrode had high breakdown voltage, good resistance—temperature property,high reliability and strong adhesive power between substrate and electrode.Nickel chromium alloy was cheaper than nickel, and its sputtering aggradation velocity was more than that of nickel, so the immediacy costs of sputtering nickel chromium alloy electrode was less than that of sputtering nickel electrode. If the productivity and the utilization ratio of target materials could be advanced, and the continuous mass production could be guaranteed, the sputtering nickel chromium alloy electrode would be a promising prospect in the future industrial application.