Bernoulli pickup head with self-restoring anti-tilt improvement
AssigneeInternational Business Machines Corporation
InventorsDonald Harlem Apgar, Richard Fleming Kilburn
Life of this patent
Estimating the term…
Abstract
A pickup head, which is of the type referred to in the art as a Bernoulli pickup head, is used to lift and/or transport a semiconductor wafer. The head is provided with a central positive pressure gas coupled orifice or port and at least three auxiliary positive pressure gas coupled orifices disposed symmetrically about the central orifice. The gas flow from the central orifice effects the main lifting force and the gas flow from the auxiliary orifices effects additional restoring torque to correct for any wafer tilt, if present. Thus, the integrity of the non-contacting relationship between the head and wafer surface is enhanced and/or preserved and this is particularly advantageous on lift-off.
Claims10
Pickup apparatus of the Bernoulli type for lifting an article for support thereby, said article having a predetermined planar surface, said apparatus comprising:
- a pickup head,
- central main orifice means disposed on said pickup head and adapted to be coupled to a positive pressure gas supply, said main orifice means providing a gas flow discharge therefrom towards said predetermined planar surface for effecting the lifting and support of said article, and
- at least three auxiliary orifice means disposed on said pickup head in a predetermined symmetrical manner about said main orifice means and adapted to be coupled to a positive pressure gas supply, said auxiliary orifice means providing gas flow discharges therefrom towards said predetermined surface for effecting a restoring torque to said article whenever said planar surface becomes tilted in any direction with respect to said pickup head.
Pickup apparatus of the Bernoulli type for lifting a circular planar semiconductor wafer for support thereby, said wafer having a predetermined diameter magnitude and a predetermined planar surface for coacting with said apparatus, said apparatus comprising:
- a pickup head having upper, middle and lower cylindrical sections concentrically aligned about a common vertical axis of said head, said upper, middle and lower sections having first, second and third diameter dimensions, respectively, of decreasing magnitude, said second diameter dimension being substantially equal to said wafer diameter magnitude,
- a central orifice disposed on said lower section concentrically about said central vertical axis and in facing relationship to said planar surface at the center of said wafer, and
- at least three auxiliary orifices disposed on said middle section in a predetermined symmetrical manner about said central orifice and in facing relationship to said planar surface between the circumferential periphery and center of said wafer, and
- means for coupling said main and auxiliary orifices to a positive pressure gas supply, said main orifice providing a gas flow discharge therefrom towards said planar surface at the center of said wafer for effecting the lifting and support of said wafer, said auxiliary orifices providing gas flow discharges therefrom towards said predetermined surface between said circumferential periphery and center of said wafer for effecting a restoring torque to said wafer whenever said planar surface becomes tilted with respect to said head.
Dependencies are inferred from the claim text.