The evaluation of anisotropically conductive film for use in portable electronic products

Abstract

Summary form only given, as follows. The use of anisotropically conductive film as an interconnect method for direct flip chip attach and for flex to glass offers many benefits to both product designers and SMT assembly engineers. However, as the technology in is relatively new, data on both processing conditions and field performance is limited. This paper is divided into two sections. Firstly, the processing parameters that influence the quality of joints obtained with ACF and how these processes can be optimised. Particular emphasis is given to the effect of processing conditions to joint reliability and electrical performance. The effect of storage conditions and the exposure of unused film will be examined. This data was gathered during the evaluation of an ordered anisotropic film material for use with flip chips. The second part of the paper concentrates on the performance of the material in a variety of environmental and stress tests used to simulate field conditions, including thermal shock, and high temperature and humidity environments. Particular emphasis will be given to the evaluation of the drop impact resistance of the adhesive joints, with background information on the measurement techniques used to simulate the impacts experienced by portable electronic devices such as CD players and mobile phones. This paper should provide a useful introduction to both product designers and process engineers interested in the use of anisotropic adhesives as an interconnect solution in portable electronic products.