SMM to Expand COF Capacity by Semi-Additive Method in Taiwan

Sumitomo Metal Mining (SMM) announced on Monday the firm triples the output capacity of COF (chip on film) manufactured by the semi-additive process. COF is a film substrate for mounting liquid-crystal-display driver ICs. SMM will establish COF productive lines with a capacity at 10 million units per month in Taiwan. After that, the firm will transfer the domestic productive lines to Taiwan. Taiwanese COF capacity by the semi-additive process will total 15 million units per month finally. The firm invests 3.6 billion yen for this expansion.SMM has produced COF by the semi-additive method at approximately 5 million units per month in Ome plant (Electronics Division, Tokyo) and Ohkuchi Electronics (the productive subsidiary in Kagoshima, Japan) since autumn 2007. The new method performs wiring formation by plating instead of by traditional etching. Wiring widths, positioning and shaping are easily controlled by the process, which enables very precise wiring with a 20-micron pitch.LCD driver IC productions are rather integrated in Taiwan, about 40% of the global production. SMM aims to raise its global COF shares from current 10% to 20% by this expansion. SMM holds COF output capacity by the etching method at 40 million units per month in Taiwan other than the semi-additive process.