Abstract: The present invention provides a method and apparatus for fabricating densely stacked ball-grid-array packages into a three-dimensional multi-package array. Integrated circuit packages are stacked on one another to form a module. Lead carriers provide an external point of electrical connection to buried package leads. Lead carriers are formed with apertures that partially surround each lead and electrically and thermally couple conductive elements or traces in the lead carrier to each package lead. Optionally thin layers of thermally conductive adhesive located between the lead carrier and adjacent packages facilitates the transfer of heat between packages and to the lead carrier. Lead carriers may be formed of custom flexible circuits having multiple layers of conductive material separated by a substrate to provide accurate impedance control and providing high density signal trace routing and ball-grid array connection to a printed wiring board.

Abstract: A device for producing a hermetically sealed chip carrier is taught. Briefly stated, a sealing or perimeter ring is formed on a substrate with an appropriate lead pattern and IC chip contained within this ring. Vias or ducts are disposed in the substrate with metal lead pedestals contained therein which provide electrical connection through the substrate and therefore between the lead pattern contained inside the sealing ring and the lead patterns on the outside of the sealing ring. This therefore allows for a continuous sealing ring such that a cap may be placed on top of the sealing ring and bonded by methods such as welding so as to form a hermetically sealed enclosure.