Demountable tape-automated bonding method

Abstract

Abstract A Demountable Tape-Automated Bonding System for providing connections to a chip is disclosed. The chip is attached to or is held in place on a TAB frame that includes a generally flexible dielectric film which bears a pattern of conductive traces. A multitude of closely-spaced contacts which protrude downward from the chip contact the conductive traces on the TAB frame. The chip may be maintained in its proper location on the TAB frame by either a bonding agent or by compressive forces supplied by a cap which is fastened to the TAB frame and to a substrate, such as a printed circuit board, below the TAB frame. The substrate carries an array of conductive traces around the edges of the substrate. These traces match the traces on the TAB frame. The conductor traces on the TAB frame and on the substrate are held in contact with each other by compressive forces supplied by the cap which is fastened to the TAB frame and to the substrate. An optional bottom plate may be affixed beneath the substrate to provide additional strength and rigidity to the assembly. An optional heat sink may be attached above the cap to conduct away heat generated by the chip. An alternative embodiment of the invention includes an elastomer which is inserted between the cap and the substrate to cushion the compressive forces borne by the chip. The invention may also utilize a heat spreader placed directly above the chip. The Demountable Tape-Automated Bonding System constitutes a major improvement in the electronics industry which provides reliable, removable connections to delicate integrated circuit chips, eliminates the need for soldering, greatly diminishes alignment and bonding requirements, and offers a modular chip package that guards against mechanical, chemical, and electrical threats to its contents.

Inventors

• 👤 Farid Matta
• 👤 Kevin C. Douglas

Bibliographic Details