【作者】 刘志强；

【导师】 王新波；

【作者基本信息】 哈尔滨工业大学 ， 材料工程（专业学位）， 2018， 硕士

【摘要】 聚酰亚胺类材料由于其优异的化学稳定性、耐低温性、很好的机械性能、优良介电性能在微电子行业得到广泛地应用,但随着集成电路不断微缩化,互联导线间的信号延迟等问题对聚酰亚胺材料提出了更高的要求,因此制备多孔性低介电常数的聚酰亚胺薄膜成为了研究热点。本文采用了两种不同的方法制备了具有较低介电常数的聚酰亚胺薄膜,同时制备了聚酰亚胺多孔块体,并对其性能进行了研究。本文合成了低分子量端氨基聚硅氧烷和以双硫醚类链转移剂合成的端氨基聚苯乙烯,通过端基反应合成了聚酰亚胺-b-聚硅氧烷嵌段共聚物和聚酰胺酸-b-聚苯乙烯嵌段共聚物,然后通过热降解处理和酸腐蚀处理去掉聚苯乙烯和聚硅氧烷成分,得到两种多孔聚酰亚胺薄膜,对多孔薄膜的介电性能、热性能、吸附性、表面性能进行了表征,发现随着孔隙率的增加,薄膜介电性能呈线性降低趋势,同时,复合膜的热稳定性随着添加聚苯乙烯和聚硅氧烷的量而降低,薄膜对水和甲苯具有较好的吸附性,随着孔隙率的增加,吸附量依次增加,而且嵌段共聚物薄膜随着聚苯乙烯和聚硅氧烷的加入接触角逐渐增大,当聚苯乙烯和聚硅氧烷被腐蚀掉之后则接触角降低,薄膜表面产生凹坑结构且薄膜表面粗糙度增加。采用甲苯二异氰酸酯和二苯基甲烷二异氰酸酯作为混合异氰酸酯与均苯四甲酸酐聚合成可溶性聚酰亚胺,然后采用多异氰酸酯交联剂制备聚酰亚胺多孔块体,通过调节酸酐部分与异氰酸酯的比例,制备出三种不同交联密度的组分。然后进行浸置水或者高压反应釜处理得到多孔性聚酰亚胺块材,研究发现通过反应釜处理得到的块材孔径尺寸均一,分布均匀,通过浸渍水处理得到的多孔块体周期较长,同时,当凝胶块的交联密度增大时,对水和甲苯呈现出较好的吸附性能。综上所述多孔聚酰亚胺薄膜具有较低的介电常数,较好的吸附性能,具有一定的热稳定性,而且采用低分子量聚硅氧烷和双硫醚类链转移剂制备的端氨基聚苯乙烯有效改善了合成嵌段共聚物时的溶解性问题;合成多孔聚酰亚胺块体时采用了可溶性聚酰亚胺,避免了高温热酰亚胺化造成的热降解,而且块体对甲苯和水具有较好的吸附性能。更多还原

【Abstract】 Polyimide materials have been widely used in microelectronics industry because of their excellent chemical stability,low temperature resistance,good mechanical properties and excellent dielectric properties.However,with the continuous shrinking of integrated circuits and the signal delay between interconnections,higher requirements for polyimide materials are required.Therefore,the preparation of porous polyimide films with low dielectric constant has become a research hotspot.In this paper,polyimide films with low dielectric constant were fabricated by two different methods,and polyimide porous bulks were prepared,and their properties were studied.In this paper,amino terminated polysiloxane with low molecular weight and terminal amino polystyrene synthesized by disulfide chain transfer agent were synthesized,polyimide-b-polysiloxane block copolymer and polyamide acid-bpolystyrene block copolymer were synthesized by end group reaction.Then two kinds of porous polyimide films were obtained through thermal degradation of polystyrene block and hydrofluoric acid etching of polysiloxane block,respectively.The dielectric properties,thermal properties,adsorbability and surface properties of the porous films were characterized.It is found that the dielectric properties of the films decrease linearly with the increase of porosity,while the thermal stability of the composite films decreases with the amount of polystyrene and polysiloxanes increased.The obtained porous films have better adsorption capacity of water and toluene,and the adsorption capacity increases with the increase of porosity.Moreover,the contact angle of block copolymer films increases with the addition of polystyrene and polysiloxane.When the polystyrene and polysiloxane were eroded,the contact angle decreased,and the surface of the film formed pits structure,and the surface roughness of the films increased.Toluene diisocyanate and diphenylmethane diisocyanate were used as mixed isocyanates to sythesize soluble polyimides with pyromellitic dianhydride.Polyimide porous bulks were prepared by polyisocyanate crosslinking agent.By adjusting the proportion of anhydride and isocyanate,three kinds of components with different crosslinking densities were prepared.Then the porous polyimide bulk is obtained by impregnated water or high pressure reactor.It is found that the pores have uniform size and distributes evenly in the polyimide matrix through the reaction kettle.The porous bulk obtained by the treatment of water needs more time,and its adsorbabilityproperities of water and toluene are better when the crosslinking density of the gel increases.In summary,porous polyimide film has lower dielectric constant,better adsorption property and certain thermal stability.Moreover,low molecular weight polysiloxane and terminal amino polystyrene prepared by disulfide chain transfer agent can effectively improve the solubility of synthetic block copolymers Soluble polyimide was used to synthesize porous polyimide block,avoiding thermal degradation caused by high temperature imidization,moreover,the bulk has good adsorption properties for toluene and water.更多还原