A lead free aluminum electrode slurry of PTC thermo-sensitive resistor and preparation method

Abstract

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.

Description

technical field

[0001] The invention relates to electronic paste for resistors, in particular to a lead-free aluminum electrode paste and a preparation method thereof. Background technique

[0002] PTC ceramic thermistor is one of the most widely used electronic ceramic components in recent years. In its production, a large amount of precious metal silver is used as the paste electrode every year. Due to economic and technical reasons such as the high price of silver and the migration of silver ions, many manufacturers use composite electrodes to improve. Such as electroless nickel plating with silver coating, electroless nickel plating and electroplating tin electrodes, which not only increases the difficulty of process operation, but also tends to cause the degradation of electrode surface quality, and make a large number of chips scrapped. Recently, some foreign manufacturers have used arc spraying, swallow plating, sputtering and other means to prepare aluminum conducti...