Development Of New Anisotropic Conductive Films

Traditional brazing processes cannot be effectively used in some fields.People in the field of electronic packaging are increasingly interested in non-welding process technology to replace the tin-based brazing process that has been used for many years.Non-welding is the most widely studied in bonding processes.Conductive adhesives are alternative to the traditional brazing process currently.Anisotropic conductive films(ACF)have been widely used in the display field as a new bonding technology.Compared with traditional brazing process,the bonding process is simple,at low temperature,capable of fine pitch connection,and environmentally friendly.However,anisotropic conductive films also have some shortcomings,such as insufficient toughness,low electrical conductivity,corrosion to materials,complicated preparation processes,and high cost.This paper starts from how to prepare a new type of anisotropic conductive adhesive to achieve a reduction in production cost and higher conductivity,contributing to the development and production of high-performance domestic electronic materials.This thesis aims to prepare anisotropic conductive films(ACF)with excellent performance,such as good adhesion properties,high toughness,and long shelf life.This thesis systematically summarizes the development of new anisotropic conductive adhesives.First,the epoxy resin was toughened and reinforced.We performed functional group analysis on the prepared modified epoxy resin,and tested its mechanical properties,and analyzed and discussed the tested results.In order to solve the problem of short storage time of the anisotropic conductive films,a few curing agents were prepared by microcapsule coating.The prepared curing agent microcapsules were tested for the coverage ratio.Moreover,they were compared with the conventional curing agent to obtain a curing agent microcapsule which can be stored for a long time.Finally,the preparation of a few kinds of anisotropic conductive adhesive films has been investigated and their performance was evaluated.By controlling the conductive particle content,bonding pressure,bonding temperature and bonding time,mechanical properties and electrical conductivity tests were carried out to obtain the best bonding parameters,and the results were analyzed.Studies have shown that the toughness of epoxy resin is improved by modifying the epoxy resin with carboxyl-terminated nitrile rubber and polyurethane.Dimethylimidazole,diphenyl imidazole,boron trifluoride ethylamine complex and heptadecyl imidazole were encapsulated into microcapsules by evaporating the solvents.The microspheres were able to be stored for a long time when blending with epoxy resin.Using the modified epoxy resin and the microcapsule-based curing agents,novel anisotropic conductive films were prepared.After the optimization of a series of experimental conditions and parameters,the best ACF performance in this thesis was obtained by using conductive particles with 20 wt.% in the resins,the bonding pressure of 0.3MPa,the bonding temperature of 170°C,and the bonding time of 12 s.