Explanation

It is also called organic adhesive. The function of organic carrier is to mix and disperse metal powder, glass powder for bonding and other solid powder into paste slurry, so as to print it on ceramics substrate by screen printing. According to the usage situation, there are the following requirements for organic carriers: ① They should be chemically inert. When the carrier contacts with the body powder, no chemical reaction can occur. ② Can form suspension. The surface tension at the phase contact interface between the carrier and the same powder particle should be small to ensure good infiltration between solid and liquid. There should be polar groups in the liquid that can stabilize elonrolyte, and there should be no excessive coagulant to prevent the slurry from condensation and deterioration during long-term storage. ③ Moderate rheological properties. The combination of the carrier and solid powder particles may provide components of a network structure, forming a plastic flow thixotropic system. The viscosity of the carrier is required to be moderate and adjustable. ④ Moderate volatility. The saturated vapor pressure of the carrier should be lower at room temperature. But at a certain temperature, the solvent in it should be easily volatile. It can quickly evaporate at high temperatures, so that the screen printing slurry does not produce secondary flow phenomenon. ⑤ Good bonding performance. The carrier soaks on the surface of ceramics substrate. Therefore, its surface tension should be adapted so that it can firmly adhere to the substrate. ⑥ Other features. The carrier shall have no fixed boiling point and gradually vaporize and combustion during heating to avoid pinholes on the resistance film. The carrier is composed of solvent (volatile component), thickener (non-volatile component is also called coagulant), mobility control agent, surfactant, etc. Each component can be composed of one or several materials.

Classification