Three-Dimensional Tape Automated Bonding
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
Tape automated bonding (TAB) is used to assemble semiconductor chips 1. For this purpose, there is a two-dimensional fan-out of the connecting lines 2 from the chip to the respective next wiring medium 3, say, a circuit card. Card technology requires that the conductor spacing be considerably in excess of that used on chips. This leads to relatively long fan-outs, as shown in the plan view of Fig. 1. The space needed for such long lines is several times that consumed by the chip. In addition, those lines have a high inductance which adversely affects the transmission speed. As a result of etching, the conductor spacing on the card will invariably exceed that on the chip, which limits fan-out. However, conditions are improved by a three-dimensional fan-out of the connecting lines 2.