The invention discloses a lead-free
aluminum electrode paste for a PTC
thermistor and the preparation method, the
electrode paste is composed of the raw materials with the following parts by weight: 55 to 70 parts of aluminum
powder, 10 to 20 parts of inorganic binder, 15 to 25 parts of organic binder and 2 to 4 parts of auxiliary; wherein, the organic binder is composed of 2 to 5 parts by weight of
ethyl cellulose, 3 to 6 parts by weight of
butyl carbitol, 15 to 23 parts by weight of
butyl carbitol acetate, 2 to 4 parts by weight of
benzyl alcohol, 60 to 70 parts by weight of
terpineol, 0.5 to 2 parts by weight of phenolic resin and 1 to 4 parts by weight of
castor oil; and the auxiliary is composed of 30 to 50 parts by weight of Bi2O3 and 50 to 70 parts by weight of
phosphorus red. The
electrode paste can prepare the aluminum
conductive paste by rolling, an
aluminum electrode can be formed by
screen printing and
sintering on a doped
barium titanate semiconductor substrate within the range of 630 plus or minus 20 DEG C, the
electrode and the substrate form good
ohmic contact, the adhesion is good, the aluminum membrane
dose not shed, and the long-term placement of the electrode has no oxidation.