Effects of mechanical and flow properties of encapsulating resin on the performance of ultra thin tape carrier package

A new ultra thin tape carrier package (TCP) for memory card was developed to meet demands for smaller and thinner TSOP. The thickness of package and Si chip are 0.4 and 0.2 mm, respectively. In order to achieve thin packages, the technology of tape automated bonding (TAB) is required. Nitto´s transfer molding technology is used to obtain the same level of both reliability and conventional reflow solderability as those of other surface mount devices (SMDs). The upper and side surface of the Si chip are encapsulated with resin, but the bottom surface is still exposed. In this paper, four kinds of epoxy encapsulating resins with different filler volume fractions were prepared to obtain various mechanical and flow properties. The effects of the coefficient of thermal expansion and viscosity of the encapsulating resin on the performance of the new ultra thin packages are studied