US 9,849,557 B2 · Coupling mechanism, substrate polishing apparatus, method of determining position of rotational center of coupling mechanism, program of determining position of rotational center of coupling mechanism, method of determining maximum pressing load of rotating body, and program of determining maximum pressing load of rotating body

Abstract

A coupling mechanism which enables a rotating body to follow an undulation of a polishing surface without generating flutter or vibration of the rotating body, and can finely control a load on the rotating body on a polishing surface in a load range which is smaller than the gravity of rotating body is disclosed. The coupling mechanism includes an upper spherical bearing and a lower spherical bearing disposed between a drive shaft and the rotating body. The upper spherical bearing has a first concave contact surface and a second convex contact surface which are in contact with each other, and the lower spherical bearing has a third concave contact surface and a fourth convex contact surface which are in contact with each other. The first concave contact surface and the second convex contact surface are located above the third concave contact surface and the fourth convex contact surface. The first concave contact surface, the second convex contact surface, the third concave contact surface, the fourth convex contact surface are arranged concentrically.

Claims18

Dependent claims

A coupling mechanism for tiltably coupling a rotating body to a drive shaft, comprising:

an upper spherical bearing and a lower spherical bearing disposed between the drive shaft and the rotating body,
wherein the upper spherical bearing includes a first sliding-contact member and a second sliding-contact member which are sandwiched between the drive shaft and the rotating body,
the first sliding-contact member has a first concave contact surface, and the second sliding-contact member has a second convex contact surface which is in contact with the first concave contact surface,
the lower spherical bearing includes a third sliding-contact member attached to the drive shaft, and a fourth sliding-contact member attached to the rotating body,
the third sliding-contact member has a third concave contact surface, and the fourth sliding-contact member has a fourth convex contact surface which is in contact with the third concave contact surface,
the first concave contact surface and the second convex contact surface are located above the third concave contact surface and the fourth convex contact surface, and
the first concave contact surface, the second convex contact surface, the third concave contact surface, and the fourth convex contact surface are arranged concentrically.

4 more elements

A non-transitory computer-readable storage medium storing a program of determining a maximum pressing load of a rotating body which is tiltably coupled to a drive shaft through a coupling mechanism which includes an upper spherical bearing and a lower spherical bearing having a same rotational center,

the program causing a computer to perform operations of:
calculating a critical value of a pressing load in a translational motion, which can prevent flutter or vibration of the rotating body, from a stability condition expression for the translational motion which is specified based on an equation of motion for the translational motion of a displacement portion which can tilt about the rotational center when the rotating body is in sliding contact with a polishing pad supported by a rotating polishing table, while rotating the rotating body;
calculating a critical value of a pressing load in a tilting motion, which can prevent flutter or vibration of the rotating body, from a stability condition expression for the tilting motion which is specified based on an equation of motion for the tilting motion of the displacement portion when the rotating body is in sliding contact with the polishing pad supported by the rotating polishing table, while rotating the rotating body;
comparing the critical value of the pressing load in the translational motion with the critical value of the pressing load in the tilting motion;
if the critical value of the pressing load in the translational motion is smaller than or equal to the critical value of the pressing load in the tilting motion, determining that the critical value of the pressing load in the translational motion is the maximum pressing load of the rotating body;
and
if the critical value of the pressing load in the translational motion is larger than the critical value of the pressing load in the tilting motion, determining that the critical value of the pressing load in the tilting motion is the maximum pressing load of the rotating body.

4 more elements

Dependencies are inferred from the claim text.

Life of this patent

Life of this patent

Abstract

Claims18