Preparation And Properties Of Polyimide Films With Low Thermal Expansion Coefficient

The advent of the information age has made microelectronic technology infiltrated into various industries,and has become one of the main driving forces for promoting social development.It is the basis of computer and Internet industries.It has far-reaching impact on national defense,education,health,transportation,post and telecommunications,economic management and so on.The chip is the most basic unit for information system to realize functions,and encapsulation materials provide support and protection for the normal operation of the system.Polymer materials play an important role in packaging materials because of their low cost and excellent comprehensive performance.In this,polyimide(PI)has the best heat resistance and good insulation.With the popularization of 14nm process technology,three-dimensional packaging technology and surface mounting technology,and the rapid development of flexible circuit board market,microelectronic technology has put forward higher requirements for the thermal dimensional stability of packaging materials(CTE).In this study,a hydrogen bonded polyimide was prepared by introducing a two amine monomer 4,4'-Diaminobenzanilide(DBN)with an amide bond structure.The structure of the main chain was controlled by adjusting the type and content of the monomer,thus the thermal expansion coefficient was regulated,and its mechanical properties and thermal properties were optimized.In this paper,the PMDA-ODA-DBN polyimide film of different copolymerization systems was prepared by using flexible 4,4'-Oxydianiline(ODA)and DBN and Pyromellitic Dianhydride(PMDA).The films exhibit excellent mechanical and thermal stability.In order to study the effect of the flexible bond on the hydrogen bonded polyimide,Bis-(3-phthalyl anhydride)ether(ODPA)was used as the carrier to introduce the ether bond into the main chain.In addition,the performance difference between PDA system and DBN system is compared.The results show that the modulus of ODPA:PMDA and DBN:PDA can be adjusted to 7.9GPa,the strength is more than 300MPa,Tg is higher than 400 ?,CTE is controlled between-7.58?36.02 ppm/?,and CTE database is set up by multiple linear regression equation to realize quantitative analysis and prediction.