:)
We developed a so-called "reel-to-reel method" COF technology using a long carrier tape for the LCD driver
package. This method enables mass production of COF. We used the ILB (inner lead bonding) technique that
connects inner leads on a 2-layered tape (glue-less) to Au bumps on an IC chip. COP tape material should be
carefully selected with respect to both thermal expansion and heat resistance, because the IC chips are
connected to the tape at a temperature over 400 C. In cooperation with a resin maker, we developed the
underfill material, which enables filling the narrow spaces between the IC chip and the 2-layered chip
without bubbles. The 2-layered tape also features easy installation onto CR parts and is flexible enough to
bend freely. These features offer a promising advantage when this method is applied to compact appliances
such as cellular phones and PDAs.