Die attach system
A die attach system includes a substrate that has scored grooves or into which stud bumps on a die are then inserted. The additional surface area and flow of the stud bumps into the trenches creates a strong mechanical bond that may withstand repeated thermal cycling. In a further exemplary aspect, the substrate may be covered in a first material, the stud bumps may be made from the same first material, a die attachment material may be made from the same first material, and a bottom layer of the die may be made from the same material. This material homogeneity allows for more uniform expansion and contraction during thermal cycling, preventing failure of the mechanical bond.
1 . An assembly comprising:
a die comprising:
one or more transistors therein; and
a bottom surface;
a substrate comprising;
a bottom layer; and
a top layer positioned on the bottom layer, the top layer comprising a top surface, the top surface comprising a plurality of grooves thereon, wherein each of the grooves comprises a continuous line with a rectilinear cross-section, wherein each of the plurality of the grooves further comprises a groove bottom surface; and
a plurality of stud bumps extending from the bottom surface to at least one groove bottom surface of the plurality of grooves.
2 . The assembly of claim 1 , further comprising a die-attach material surrounding the plurality of stud bumps and extending between the top surface and the bottom surface.
3 . The assembly of claim 1 , wherein the top surface further comprises a trench spaced inwardly from a perimeter of the substrate and extending around the perimeter of the substrate.
4 . The assembly of claim 1 , wherein each groove of the plurality of grooves has a depth of approximately 0.5 to 1.5 millimeters (mm).
5 . The assembly of claim 1 , wherein the plurality of grooves are arranged in a series of parallel lines.
6 . The assembly of claim 5 , wherein the series of parallel lines have a pitch of approximately 30-100 microns (pm).
7 . The assembly of claim 1 , wherein each groove of the plurality of grooves has a width of approximately 0.5 to 1.5 millimeters (mm).
8 . The assembly of claim 1 , wherein the plurality of stud bumps have a vertical dimension of approximately 0.1 to 0.5 millimeters (mm).
9 . The assembly of claim 1 , wherein the top surface, the bottom surface, and the plurality of stud bumps all comprise a first substantially homogeneous material.
10 . The assembly of claim 9 , wherein the first substantially homogeneous material comprises gold (Au) or a gold alloy.
11 . The assembly of claim 10 , further comprising a die-attach material comprising the first substantially homogeneous material.