Outer Lead Bonding Process Conditions For TFT-LCD Module

Abstract

Outer lead bonding (OD) of a TAB tape to a LCD glass panel is an important step in m a h g FT-LCD modules. me OLB process uses a t h e d to heat and press TAB leads against an IT0 patterned glass Hit6 an Anisotropic ConductiE Film (ACF) in k m n . l3e tempenture at the ACF, the ali&ment betwefir TAB leads and IT0 patterns at&.? the integrity of bond betwen the lFT-LCD modules and the TAB IC driver. l&pziment shows that only 20% of the particle contact mea is adequate fir a low interconnection resistance of' -TO Q. The temperature at the interhe between the ACF a!m and the m0 glass is another important parameter. Depc:nding on the thickness of the polyimide h, the temperature ditErence between the thermode and the ACF interhce can be as large as 300 OC. Another parameter used in this study is the "thennode up" temperature. Experiments with tw &&rent "thermode up" temperaatures of 340 OC and 80 OC wre studied. Mer the OLB bonding, the bonds wnt through temperature cycling betwen -40 OC and 100 'OC fbr 200 cycles. A lower "thermode up temperature has a sli@tly better resistance to thermal cycling test than those with a Egher "thennode up" temperature.