Patent ID: 7938311

Claim:
A hybridization method, comprising the steps of: providing a first component with first pads for accommodating solder protrusions of a single fusible material, said first component having a first thermal expansion coefficient and a planar shape having a central region on a first surface thereof; providing a second component with second pads and third pads for accommodating said solder protrusions, said second component having a second thermal expansion coefficient and a planar shape having a central region on a second surface thereof, wherein said first and second pads having a first predetermined solder pad size are positioned on said first and second components, respectively, such that, at a hybridization temperature of said solder protrusions, said first and second pads of each pair of pads are substantially superimposed to form aligned pairs of pads, and such that, at ambient temperature, said first and second pads of each pair of pads are offset relative to one another by a distance that compensates for differential expansion of said first and second components between the ambient and said hybridization temperature; positioning said solder protrusions on said first pads of said first component, wherein some of said solder protrusions are taller than the remainder of said solder protrusions so that before the temperature is increased to the said hybridization temperature, said first and second components contact one another only through said taller solder protrusions, and wherein said third pads of said second component are a second predetermined solder pad size, which is larger than said first predetermined solder pad size of said first and second pads, whereby said third pads are positioned opposite to said taller solder protrusions, said taller solder protrusions being positioned only in the central region of said first component such that at least one of said taller solder protrusions at least partially overlaps the geometric center of said first component, and wherein the composition of all of said solder protrusions is the same; placing said second component on said first component to form an assembly, wherein said third solder pads are positioned directly above and in contact with said taller solder protrusions; heating said assembly to said hybridization temperature in order to interconnect each pair of opposed pads by soldering said solder protrusions to the pads; and cooling the resulting soldered assembly, wherein all of said solder protrusions in the resulting soldered assembly have convex side surfaces when viewed in cross section taken through a plane perpendicular to main planes of said first and second components.