Preparation And Properties Of Porous Low Dielectric Polyimide Composite Films Polyimide Composite Films

Polyimide stands out because of its excellent electrical properties,thermal stability,mechanical properties and low moisture absorption,but with the rapid development of microelectronics,especially in the application of large-scale integrated circuits,its dielectric properties also have some limitations.In order to solve the shortcomings and shortcomings of the above prior art,this paper will increase the space volume and reduce the packing density by adding mesoporous materials to the polyimide film,which can effectively reduce the dielectric constant of the polyimide film,improve its insulation and avoid the problem of phase separation.By referring to relevant literature,this paper summarized the detection indexes of dielectric materials,the relationship between polyimide properties and structure,the research progress and application of porous low-dielectric polyimide materials,and put forward the research innovation points of this paper,and then carried out the following research work.Based on the polyimide obtained by polycondensation of fluorinated 4.4-diaminodiphenyl ether and homophenyltetramethylanhydride,the effects of internal structural factors such as space volume,packing density and solubility parameters on the dielectric properties of polyimide films were investigated by adding mesoporous materials such as hollow polymer and hollow mesoporous silicon dioxide.The results show that the dielectric properties increase with the increase of large volume groups and mesoporous materials with fluoride content.The solubility parameter is positively correlated with the dielectric constant,and the free volume is negatively correlated with the dielectric constant,providing theoretical basis for the next experiment.The properties of the composite films were studied by using fluorinated polyimide structure and adding mesoporous materials.Firstly,hollow mesoporous SiO₂ was synthesized,N-methylpyrrolidone（NMP）dissolved polyimide intermediates,and the prepared hollow mesoporous SiO₂ was added after complete dissolution.The effects of different amounts of hollow mesoporous SiO₂ added on the properties of polyimides were explored.By increasing the volume of air to reduce the dielectric constant,the heat resistance,mechanical properties,surface morphology and dielectric properties of the film were measured.The experiment showed that the film uniformly formed and had good heat resistance,the thermal decomposition temperature was 375℃,the tensile strength was 384Mpa,the elongation at break was 3.63,and the dielectric constant was about 3.39.In addition,the polyimide intermediates were dissolved by N-methylpyrrolidone（NMP）,and hollow polymers were added after complete dissolution.The heat resistance,mechanical properties,surface morphology and dielectric properties of the film were measured.The experiments showed that the film uniformly had good heat resistance and mechanical properties.The thermal decomposition temperature was 448℃,the tensile strength was 367.75 Mpa and the elastic modulus was 8005.95 MPa,and the dielectric constant was about 3.50.