The invention relates to a SMD type PTC
thermistor preparation method, and belongs to the field of
electronic component preparation. The preparation method comprises: mixing BaTiO3, SrCO3, MnO2, Y2O3, SiO2 and
graphite to prepare a spare material, and carrying out ball milling by using a 200 kg mill ball, wherein the ball milling media uses agate balls; pre-burning, wherein the pre-burning process uses a tunnel furnace; granulating, carrying out pressing molding after completing the granulating, and
sintering by using a bell furnace; and finally
welding an
electrode by using a
reflux welding manner to prepare the
thermistor. According to the present invention, through the
process improvement, the small size sheet-like surface adhesion type
ceramic overcurrent protection element is prepared, such that the area of the circuit board is substantially reduced, the
assembly process is simplified, and the circuit density is improved; and by adding the
graphite, the micro-pores are formed in the
ceramic so as to increase current resistant of the
ceramic sheet.