Shaped, self-aligning micro-bump structures

Abstract

Positive mechanical alignment is provided between substrates using micro-bump contacts by forming "detented" conductive bump contacts on one substrate having a concave end which receive and align the generally convex contour of bump contacts on the other substrate. Various configurations of concavities and convexities are described. Flux may be disposed in the concave end of the detented bump contact to promote formation of joints between the concave and convex bump contacts. Both bump contacts may be formed of reflowable material, such as solder, or one or the other of the contacts may be formed of a non-reflowable material which may also function as a standoff between the two substrates. Each substrate is provided with a plurality of bump contacts, and one substrate may be provided with a combination of convex and concave bump contacts corresponding to concave and convex bump contacts on the other substrate. The inventive technique is useful for joining die-to-die, die-to-substrate, or package-to-substrate.

Dependencies are inferred from the claim text.