US 5,867,590 A · Method and apparatus for determining a location on a surface of an object

Abstract

The present invention provides a method for determining a location on an object without prealignment and for positioning an object, such as a semiconductor, which has an array of generally perpendicular grid lines on its surface and a plurality of directional features. According to one embodiment the method determines the directions for the grid lines relative to the direction of a reference coordinate system, detects a grid junction and detects a direction of a reference coordinate system, detects a grid junction and detects a direction of one of the plurality of directional features, thereby providing a location of the grid junction in the reference coordinate system. According to an alternative embodiment, the method includes the steps of determining the directions of the grid lines relative to the direction of a reference coordinate system, detecting an asymmetrical directional feature, its orientation with respect to the directions of the grid lines and the distance of the asymmetrical feature from a geometrical center of the surface being known; and detecting a direction of the asymmetrical directional feature, thereby providing a location of the asymmetrical feature in the reference coordinate system. The object is positioned in accordance with the provided location of the grid junction.

Claims18

Dependent claims

A method for determining a location on an object, said object having on its surface an array of generally perpendicular grid lines and a plurality of asymmetrical directional features, the method comprising the steps of:

a. positioning the object on a support which has a reference coordinate system;
b. determining the directions of said grid lines relative to the direction of the reference coordinate system;
c. detecting an asymmetrical directional feature, its orientation with respect to said directions of said grid lines and the distance of said asymmetrical feature from a geometrical center of said surface being known;
and
d. detecting a direction of said asymmetrical directional feature, thereby providing a location of said asymmetrical feature in said reference coordinate system;
wherein said step of detecting said at least one asymmetrical directional geometrical feature comprises the steps of:
(1) determining whether said asymmetrical feature is detected in a first location of said surface;
(2) moving to a second location on said surface;
(3) repeating said steps of determining whether said asymmetrical feature is detected in a first location of said surface and moving until said asymmetrical directional geometrical feature is detected, wherein for each location said asymmetrical directional feature has a different orientation with respect to the reference coordinate system.

6 more elements

A method for positioning an object, said object having on its surface an array of generally perpendicular grid lines and a plurality of asymmetrical directional features, the method comprising the steps of:

a. positioning the object on a support which has a reference coordinate system;
b. determining the directions of said grid lines relative to the direction of the reference coordinate system;
c. detecting a directional asymmetrical feature, the distance of said asymmetrical feature from a geometrical center of said surface being known;
d. detecting a direction of said asymmetrical directional feature, thereby providing a location of said asymmetrical feature in said reference coordinate system;
and
e. positioning said object in accordance with said provided location of said at least one asymmetrical feature;
wherein said step of detecting said at least one asymmetrical directional feature comprises the steps of:
(1) determining whether said asymmetrical directional feature is detected in a first location of said surface;
(2) moving to a second location on said surface;
(3) repeating said steps of determining whether said asymmetrical directional feature is detected in a first location of said surface and moving until said asymmetrical directional geometrical feature is detected, wherein for each location said asymmetrical directional feature has a different orientation with respect to the reference coordinate system.

7 more elements

Dependencies are inferred from the claim text.

Method and apparatus for determining a location on a surface of an object

Life of this patent

Method and apparatus for determining a location on a surface of an object

Life of this patent

Abstract

Claims18