Method of locating conductive spheres utilizing screen and hopper of solder balls
AssigneeMicron Technology, Inc.
InventorsChad A. Cobbley, Michael B. Ball, Marjorie L. Waddel
Life of this patent
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Abstract
Apparatus and methods for placing conductive spheres on prefluxed bond pads of a substrate using a stencil plate with a pattern of through-holes positioned over the bond pads. Conductive spheres are placed in the through-holes by a moving feed mechanism and the spheres drop through the through-holes onto the bond pads. In one embodiment, the feed mechanism is a sphere hopper which crosses the entire through-hole pattern. In another embodiment, a shuttle plate fed spheres from a reservoir and reversibly moves about one-half of the pitch, moving from a non-discharge position to a discharge position.
Claims10
A method for placing an array of conductive spheres on prefluxed bond pads of a substrate, said method comprising:
- providing a substrate having a surface with a first pattern of bond pads;
- providing a stencil plate having upper and lower surfaces with a second pattern of through-holes therethrough, said second pattern of through-holes corresponding to said first pattern of bond pads;
- providing a hopper with an open top and configured to receive, hold and dispense conductive spheres as said hopper is closely moved across said upper surface of said stencil plate;
- placing said stencil plate over said substrate to align said patterns;
- moving said hopper across the upper surface of said stencil plate to a position beyond said pattern of through-holes to drop said conductive spheres through said through-holes onto said bond pads;
- and
- removing said substrate from adjacent said stencil plate.
A method for placing an array of conductive spheres on prefluxed bond pads of a substrate, said method comprising:
- providing a substrate having a surface with a first pattern of bond pads;
- providing a stencil plate having upper and lower surfaces with a second pattern of through-holes therethrough, said second pattern of through-holes corresponding to said first pattern of bond pads;
- providing a shuttle plate having upper and lower surfaces with a third pattern of through-holes therethrough, said third pattern of through-holes corresponding to said second pattern of through-holes;
- providing a sphere reservoir adjacent the upper surface of said shuttle plate with an open top and configured to receive, hold and dispense conductive spheres into the third pattern of through-holes of said shuttle plate;
- placing said stencil plate over said substrate to align said first and second patterns;
- moving said shuttle plate across the upper surface of said stencil plate between a position aligned with said second pattern of through-holes and a position non-aligned with said second pattern beyond said second pattern of through-holes to drop said conductive spheres through said second and third pattern of through-holes onto said bond pads;
- and
- removing said substrate from adjacent said stencil plate.
Dependencies are inferred from the claim text.