Preparation of fine-grained PTCR with high-performance by solid state method

The PTCR (positive temperature coefficient of resistance) becomes small and small as the chip technology for the development of ceramic was growing. Thus the ceramic with fine-grain was need. The solid-phase method was used by improving the ratio of Y and Mn, in which the method of high pre-sintering temperature and low sintering was effective. When n (Y:Mn) > 21, the pre-sintering temperature and sintering temperature was separately 1220°C and 1300°C, the effect was obvious. Through those methods of inhibiting grain growth, the average grain size(less than 2 μm) was achieved, whose resistivity of room temperature was 205 Ω · cm, lift drag ratio was 4.082 × 10⁴. The fined grained ceramic of multilayer chip PTC will help in the industrialization.