Electrical evaluations of anisotropic conductive film manufactured by electrohydrodynamic ink jet printing technology

Generally, anisotropic conductive films (ACFs) used for bonding in communication devices and displays are manufactured by applying pressure to conductive particles at desired positions. The conventional production process has serious disadvantages that waste of conductive particles and the non-uniform number of particles captured, etc. In order to overcome these disadvantages, the film production using electrohydrodynamic (EHD) ink jet printing technique is proposed in this work. The EHD printing results are greatly affected by the ink properties and printing conditions. Therefore, polymer inks suitable for EHD ink jet printing are developed, and then the variation of the meniscus according to the intensity of the voltage was evaluated. As a main material of ACFs, conductive particles are added to the polymer inks to assess the feasibility of generating the ACFs using EHD technology. The results show that the electrical conductivity of the manufactured ink with conductive particles shows good performance.