Flexible contact post and post socket and associated methods therefor

Abstract

Flexible connectors having substantially vertical conductive legs allowing the connectors to accommodate deflection in the lateral directions (x-y directions in the plane of the connectors) induced by CTE mismatches between a chip and a substrate during thermal cycling of the chip. The connectors also accommodate deflections in the vertical direction (z direction--perpendicular to the plane of the connectors) which may be caused by connection to a substrate. Such substantially vertical leg features are formed using projection lithography, such as projected x-ray or ultra-violet ("UV") radiation, to selectively expose a photoresist layer such that the substantially vertical metal features may be formed by plating or etching. The sacrificial layer may be in the form of an array of posts, such that "stool-like" post connectors are created, or may be in the form of an array of apertures, such that "basket-like" receptacles or sockets are created. Such a flexible connector may be used in different applications resulting in superior device characteristics, such as: 1) a replacement for flip chip (C4) solder connections or for BGA solder connections; 2) a flexible socket element; or 3) a flexible thermal coupling element.

Dependencies are inferred from the claim text.