I. Introduction
Flip-chip assemblies using an adhesive have been increasingly applied to personal digital assistant devices, mobile phones, and liquid crystal display devices. The use of adhesive flip-chip-type electronic packages offers numerous advantages such as reduced thickness, improved environmental compatibility, lowered costs, low process temperature, and fine pitch application, in addition to being a “green” technology [1], [2]. The use of anisotropic conductive film (ACF) for the direct interconnection of flipped silicon chips to printed circuits also offers numerous advantages such as reduced thickness, improved environmental compatibility, lowered assembly process temperature, increased metallization options, cut downed costs, and decreased equipment requirements. Its wide application to glass displays through a chip on glass process has accelerated interest in using this technology on rigid/flexible substrates and even on paper substrates as novel ACFs are being developed.