The development of a new resin with high mechanical strength at a high temperature for TCP's

Abstract

The tape carrier package (TCP) is a mainstream package of LCD driver ICs. With the advancement and proliferation of personal computers and software, it has been necessary to enlarge the LCD screens and improve display quality. The area around the edge of LCD screen must therefore be narrowed to allow the display area to increase and thus provide a maximum display screen within a predetermined module size. Furthermore, display pixels with finer pitch have been developed for higher resolution, since the TCP must have higher output, finer pitch, and be miniaturized for connection to the LCD panels. Thus, in order to reduce the size of the TCP, the chip should be made slimmer, and the pad and inner lead pitch made finer. In a scaled-down TCP, the distance between the I/O terminals and the resin has been reduced. The TCP undergoes shearing stress and heat during thermal bonding while being mounted in the panels, which may result in the encapsulation resin and the tape carrier separating. Consequently, the resin must have high mechanical strength, not only at room temperature but also at higher temperatures. We have developed a high-temperature-resistant, high-mechanical strength resin whose elasticity modulus at high temperatures does not decrease and which adheres well to a tape carrier, and is suitable for use in a 309-output LCD driver with a inner lead pitch of 50 /spl mu/m and able to be mass-produced.