Patent ID: 9601398
Date: 2017-03-21
CPC Classifications: G01R,H01L

Claim:
1. A microelectronic assembly, comprising: a first substrate having a plurality of spaced-apart recesses (“recesses”) therein as extending from a first surface thereof; a second substrate having a plurality of spaced-apart solid metal pillars (“pillars”) exposed at a first surface thereof, each pillar of the pillars extending into a corresponding one of the recesses and having a base adjacent the first surface of the second substrate and an end remote from the base; a plurality of bumps, each including a bond metal, respectively exposed at ends of the pillars, at least some of the bond metal of each of the bumps at least partially disposed in corresponding ones of the recesses and solidified therein to engage with a first portion of surface area of inner surfaces of the recesses for mechanical retention to in addition to electrical conductivity with the first substrate; wherein the first portion of the surface area of the inner surfaces of the recesses are wettable by the bond metal of the plurality of bumps, and a second portion of the surface area of the inner surfaces of the recesses are non-wettable by the bond metal of the bumps at the melting point of the bond metal; a non-wettable layer disposed in the recesses corresponding to the second portion of the surface area of the inner surfaces for being adjacent to the first surface of the first substrate and for separating the first portion of the surface area of the inner surfaces of the recesses from the first surface of the first substrate to provide a non-wetting surface barrier with respect to the bond metal after being reflowed for having the bond metal remain adjacent the first portion of the surface area of the inner surfaces of the recesses after reflow; and wherein the second portion of the surface area of the inner surfaces of the at least some of the recesses comprises a reentrant surface prior to the bond metal being reflowed for mechanical retention of the first substrate and the second substrate to one another after reflow of the bond metal.