Development of Liquid Crystal Display Mounting Technology (2nd Report)

Clarification of Stretching Mechanism of Liquid Crystal Drive IC

Abstract

A high-density mounting technology for liquid crystal drive IC and liquid crystal substrates has been developed to achieve high-definition liquid crystal displays. The material to connect liquid crystal drive IC and the liquid crystal substrate is anisotropic conductive film (ACF).Formerly, 250μm connection pitch was used as a joining material between liquid crystal drive IC and liquid crystal substrate. Now, connection pitch has been increased to 50μm. To achieve this high-density mounting technology, it was necessary to clarify the stretching mechanisms for the liquid crystal drive IC and anisotropic conductive film, which have different thermal expansion rates.
Apart from the elucidation of the stretching mechanism, by the discovery of new mounting conditions to restrain the stretching, mounting technology featuring a 50μm connection pitch for joining, which had been thought impossible in the past, has been established. Thus realization of the high-definition liquid crystal display has been achieved.