Bonding tool and method for high accuracy chip-to-chip bonding
View Patent ↗A chip-to-chip eutectic bonding system includes a stage with a top surface, a bottom surface, and a plurality of vacuum apertures extending therebetween and a carrier with a top surface, the top surface including one or more smooth surface portions and one or more rough surface portions, wherein at least one smooth carrier surface portion laterally aligns to at least one vacuum aperture, and at least one of the stage's rough surface portions frictionally couples to at least one of the carrier's rough surface portions when the carrier top surface couples to and opposes the stage bottom surface.
1. A bonding tool for alignment comprising:
a stage and a carrier;
wherein:
the stage comprises a stage top surface, a stage bottom surface, and a plurality of vacuum apertures extending therebetween, wherein the stage top surface comprises one or more rough stage surface portions having an average roughness of between 50 nm and 150 nm;
the carrier comprises a carrier bottom surface, wherein the carrier bottom surface comprises one or more smooth carrier surface portions having an average roughness of less than 50 nm and one or more rough carrier surface portions having an average roughness of between 50 nm and 150 nm;
at least one smooth carrier surface portion of the one or more smooth carrier surface portions having an average roughness of less than 50 nm laterally aligns to at least one vacuum aperture of the plurality of vacuum apertures when the carrier bottom surface couples to and opposes the stage top surface; and
at least one rough carrier surface portion of the one or more rough carrier surface portions having an average roughness of between 50 nm and 150 nm frictionally couples to the at least one rough stage surface portion having an average roughness of between 50 nm and 150 nm such that frictional force counteracts lateral movement of the carrier relative to the stage.
2. The bonding tool of claim 1 , wherein the carrier is a chip carrier or a slider carrier.
3. The bonding tool of claim 1 , further comprising a heater positioned to project heat on the stage.
4. The bonding tool of claim 1 , wherein any rough carrier surface portion having an average roughness of between 50 nm and 150 nm laterally aligns to any rough stage surface portion having an average roughness of between 50 nm and 150 nm when the carrier top surface couples to the stage bottom surface.
5. The bonding tool of claim 4 , wherein any smooth carrier surface portion having an average roughness of less than 50 nm forms a disk shape pattern surrounded by any rough carrier surface portion having an average roughness of between 50 nm and 150 nm.
6. The bonding tool of claim 4 , wherein any smooth carrier surface portion having an average roughness of less than 50 nm forms a diamond shape pattern surrounded by any rough carrier surface portion having an average roughness of between 50 nm and 150 nm.