US 8,570,516 B2 · Infrared direct illumination machine vision technique for semiconductor processing equipment

Abstract

A vision system is provided to determine a positional relationship between a semiconductor wafer on a platen and an element on a processing machine, such as a printing screen, on a remote side of the semiconductor wafer from the platen. A source directs infrared light through an aperture in the platen to illuminate the semiconductor wafer and cast a shadow onto the element adjacent an edge of the semiconductor wafer. A video camera produces an image using light received from the platen aperture, wherein some of that received light was reflected by the wafer. The edge of the semiconductor wafer in the image is well defined by a dark/light transition.

Claims19

Dependent claims

A vision system for determining a positional relationship between a semiconductor wafer and an element for processing the semiconductor wafer, wherein the semiconductor wafer is on a platen that has an aperture there through and the element is located on a remote side of the semiconductor wafer from the platen, said vision system comprising:

a source of infrared light, for directing a beam of infrared light through the aperture in the platen at an acute angle to a line that is perpendicular to a surface of the semiconductor wafer to illuminate the semiconductor wafer to cast a shadow onto the element adjacent an edge of the semiconductor wafer;
and
a camera for electrically acquiring an image of reflected incident infrared light, wherein at least some of the reflected infrared light was reflected by the semiconductor wafer.

Dependencies are inferred from the claim text.

Infrared direct illumination machine vision technique for semiconductor processing equipment

Life of this patent

Infrared direct illumination machine vision technique for semiconductor processing equipment

Life of this patent

Abstract

Claims19