Study of short-circuiting between adjacent joints under electric field effects in fine pitch anisotropic conductive adhesive interconnects

ACF particle distribution in COG process

“…It can make more conductive particles remain on the bump to reduce the open probability, but the short probability is increased by the crowded particles in the limited space between adjacent bumps. The researches on conductive particle short between the adjacent bumps [9,[20][21][22][23] are fewer than the conductive resistance between the bump and glass substrate. Although some conductive resistance models were built in previous studies, only one conductive particle short model was set up by Mannan Samjid et al [20].…”

Highly reliable, fine pitch chip on glass (COG) joints fabricated using Sn/Cu bumps and non-conductive adhesives

“…COG technology is an efficient interconnection method since it eliminates the need for IC packaging and a separate circuit board. The most common COG technology currently used in display applications is based on Au bumps and anisotropic conductive film (ACF) [3][4][5][6][7][8][9][10]. An ACF is composed of an adhesive polymer matrix and fine conductive particles.…”

Statistical Characterization of Open Failures in the Fine-Pitch COG Interconnection

“…Smaller space between bumps can also be a source of bridging between bumps by the conductive particles, resulting in a short circuit. 4 Another source of open failures is nonuniform bump height throughout the driver IC. A large variation in bump height makes it difficult to form uniform interconnections between the bumps and the electrodes.…”

“…3 Many studies have focused on the reliability issues relevant to material or processing properties such as curing degree, void formation, coefficient of thermal expansion (CTE), environmental condition of humidity, temperature, pressure, etc. [4][5][6][7] This study focused on the reliability issues related to geometric design parameters such as bump area, particle size, bump height, etc., which is significant in mass production. Statistical approaches are applied to open failures in COG interconnection due to the deficiency of conductive particles and nonuniform bump height.…”