单分散聚合物/金属复合导电微球的尺寸结构设计与控制及在各向异性导电胶膜（ACF）中的作用机制

各向异性导电胶膜（ACF）是由聚合物/金属复合导电微球掺杂环氧树脂经初步固化成膜而制备的新型绿色封装材料，因具备高密度、窄间距的连接能力而备受微电子工业青睐，但却因耐低温性能差、接触电阻高、易断路和短路等原因而影响应用效果。本申请课题从分子设计角度出发，通过向导电微球内部引入柔性分子的方法增强导电微球回弹性，从而增大导电微球与接触点间的接触面积和强度，降低ACF连接接触电阻；并利用自组装方法在导电微球表面吸附SiO2绝缘层，构筑空间位阻，改善导电微球与基体树脂间相容性，降低ACF断路和短路风险；采用构建交联网络、共聚磷系单体的方法调控导电微球泊松比和界面结合力，解决导电微球金属层易剥离、破碎问题，提高ACF连接可靠性。进而探究导电微球在ACF中的作用机制，阐明微球尺寸结构与ACF可靠性间关系，构建导电微球制备新途径，为开发高性能ACF提供理论基础和科学依据，为解决“卡脖子”问题提供思路。

Anisotropic conductive adhesive film (ACF) is a kind of green packaging bonding material, which is consisted of epoxy resin and polymer/metal composite conductive microspheres. ACF has attracted more and more attention in microelectronic field due to its advanced bonding capabilities of high density, narrow spacing between devices and circuits. However, its application effect was limited due to its disadvantages such as high contact resistance, high possibility of short circuit and open circuit faults, poor resistance to low temperature. In this study, a kind of flexible molecule (e.g. butyl acrylate) was introduced into the interior of conductive microspheres to decrease the glass transition temperature of polymer microspheres, and increase the elasticity of conductive microspheres, which was useful for increasing the contact area and strength of conductive microspheres between devises and circuit. This approach can reduce the contract resistance of ACF bonding. In addition, a SiO2 insulating layer was constructed on the surface of conductive microspheres using self-assembly method to prevent short circuit and open circuit faults by promoting the compatibility of conductive microspheres in resin. The cross-linked polymer layer along with special groups containing phosphorus was constructed on the surface of polymer microspheres to adjust the Poisson's ratio and interfacial bonding force of conductive microspheres, further preventing breakages of metal layers under low temperature or high pressure conditions. The aim of this project can be concluded as following: (1) To ensure the working process and mechanism of conductive microspheres in ACF bonding process. (2) To discuss the effect of the structure or diameter of conductive microspheres to reliability of ACF bonding. (3) To invent a kind of new method to prepare conductive microsphere. (4) To provide scientific theories for developing high quality ACF. At last, this project can provide a new idea to solve the troublesome issue of economy development suggested by government.