Properties and Reliability Test of Anisotropic Conductive Film in Chip on Glass Package

Abstract

Several kind of anisotropic conductive films (ACF) with different material properties and the reliability test results have been developed in this study. The ACFs with various thermal properties, higher glass transfer temperature (Tg) and lower Tg, are developed by selecting different kind of curing agents or toughners. Reliability test also has been investigated in this study. The ACF shows perfect reliability properties after high temperature storage at 150degC for 500hrs, high temperature (85degC)/high humidity(85R.H.%) for 168 hrs and thermal cycling test (-40degC~125degC) after 500 cycles. Because of good adhesive strength of COG package, it shows good reliability properties even material with lower Tg and higher coefficient of thermal expansion (CTE).Material ACF3 shows strong shear strength (>15kgf) after ACF bonding and also after thermal aging test for 1000hrs at 85 deg;C The shear strength after ACF bonding of ACF1 and ACF2 are lower than ACF3 but they can keep the strength not to decrease after the thermal aging test. The shear strength of ACF3 is decreased much than ACF1 after 1000hrs thermal aging at 150deg;C ACF3 shows high Tg and good adhesion after bonding but ACF1 shows better adhesive properties after thermal aging test. ACF3 failed after high temperature and high humidity test (85deg;C/ 85R.H. %) because of its humidity sensitive property. ACF1 shows perfect adhesive strength after high temperature and high humidity test (85deg;C/ 85R.H.%) for 1000hrs. ACF3 has good thermal property (high Tdeg) but poor reliability properties since it's humidity sensitive. ACF1 shows perfect reliability test because of strong adhesive strength even with lower Tdeg. The ACFs with higher and lower Tdeg are both developed in this study. Good reliability properties of ACF, diamine and phenolic material, can be achieved by the strong adhesive strength in COG package even it's Tdeg is lower than 100degC