Stainless steel base material-based PTC thermistor paste and preparation method thereof

Abstract

The invention discloses stainless steel base material-based PTC thermistor paste and a preparation method thereof. The PTC thermistor paste comprises an inorganic bonding phase, a composite functional phase and an organic carrier, wherein the inorganic bonding phase is lead-free microcrystalline glass powder prepared from SiO2, MgO, B2O3, Al2O3, Bi2O3, a rare-earth oxide and a nucleation agent; the composite functional phase is composite powder prepared from micron silver powder, nano silver powder and doped copper ruthenate powder; and the organic carrier is a mixture prepared from an organic solvent, a high-polymer thickener, a dispersing agent, a defoamer and a thixotropic agent. The PTC thermistor paste is high and adjustable in sheet resistance, high and adjustable in resistance temperature coefficient and excellent in printing characteristic and burning characteristic and can be matched with an insulated stainless steel base material. The preparation method sequentially comprises the steps of preparing the inorganic bonding phase, preparing the composite functional phase, preparing the organic carrier and preparing the resistor paste. By the preparation method, the PTC thermistor paste can be effectively produced and prepared.

Description

technical field [0001] The invention relates to the technical field of electronic materials, in particular to a PTC thermistor slurry based on a stainless steel substrate and a preparation method thereof. Background technique [0002] Thick film thermistor integrates thick film technology, electronic technology and thermal technology. Thermistor paste is printed on the substrate by screen printing, dried and sintered. The thick film thermistor has the advantages of small size, adjustable resistance, good responsiveness, and good repeatability. [0003] PTC thermistors are used as self-control heating elements, overcurrent protection elements, and temperature sensors because their resistance increases with temperature rise. For a long time, the PTC thermistor is a barium titanate (BaTiO 3 ) and semiconducting thermistors, which have low resistance below the Curie temperature, but have a sharp increase in resistance of several orders of magnitude above the Curie temperature....

AI Technical Summary

Problems solved by technology

[0004] However, due to the high resistivity of barium titanate at room temperature, its application under high current capacity is limited. At the same time, due to its material itself and process defects, it leads to inherent problems such as power failure, and its current application range is limited.

Positive temperature coefficient PTC thermistor elements are mostly used in the field of microelectronics due to their poor manufacturing process and low sensitivity

Platinum, copper, and monocrystalline silicon are linear PTC thermistors. Platinum thermistors use the temperature sensitivity of precious metal platinum and can be made into filaments or films. In recent years, thin-film chip platinum resistors have also been developed. Platinum thermistors are characterized by good linearity of resistance temperature characteristics, wide temperature range, good stability, high precision, and reliable performance, but high cost; copper can also be used as thermistor material, and the temperature coefficient of resistance is larger than that of platinum resistance. , but because copper is easy to oxidize, its operating temperature is not high, and the resistivity of copper is not high, so it is generally used in occasions with low precision and low temperature; single crystal silicon resistance has good linearity and sensitivity within a certain temperature range High, fast response, etc., but its manufacturing process is more complicated and the cost is higher

[0005] In addition, for the current PTC thermistor paste, there is still a problem that the TCR is too low when the square resistance is large, which cannot meet the production needs of high resistance and high TCR thermistors.