Simultaneous wafer ID reading
The present invention discloses apparatuses and methods for simultaneous viewing and reading top and bottom images from a workpiece. The present ID reader can comprise an enclosure covering a top and bottom section of the workpiece with optical elements to guide the light from the workpiece images to a camera. The optical element can be disposed to receive images from a high angle with respect to the surface of the workpiece. The present ID reader can further comprise a light source assembly to illuminate the image. The light source assembly can utilize a coaxial light path with the images, preferably for bright field illumination. The light source assembly can also utilize a non-coaxial light path, preferably for dark field illumination.
1. A semiconductor workpiece ID reader comprising:
a camera;
an enclosure having an opening, wherein the opening is configured to enable light from a top section and a bottom section of a semiconductor workpiece to reach the camera shielded from environmental lighting;
an adjustable light source configured to illuminate the top and bottom sections of the semiconductor workpiece;
an optical assembly to guide optical paths from both the top and the bottom sections of the semiconductor workpiece to the camera;
wherein the camera is configured to image both the top section and the bottom section of the semiconductor workpiece so that a portion of an ID mark on the semiconductor workpiece is defined from specular features of both the top section and the bottom section of the semiconductor workpiece forming respective images of the top section and the bottom section with the semiconductor workpiece located at more than one different heights within the opening of the enclosure and specular features of both the top section and the bottom section of the semiconductor workpiece reaching the camera shielded from the environmental lighting with the semiconductor workpiece at each of the different heights within the opening of the enclosure; and
wherein the enclosure does not enclose the whole semiconductor workpiece.
2. The semiconductor workpiece ID reader as in claim 1 wherein the light source is configured to illuminate the top and bottom sections of the semiconductor workpiece at a substantially normal angle.
3. The semiconductor workpiece ID reader as in claim 1 wherein the light source is configured to illuminate the top and bottom sections of the semiconductor workpiece at a slant angle.
4. The semiconductor workpiece ID reader as in claim 1 wherein the light source is configured to illuminate the top and bottom sections of the semiconductor workpiece at a substantially normal angle and at a slant angle.
5. The semiconductor workpiece ID reader as in claim 1 wherein the optical assembly guides the optical paths from the top and the bottom sections of the semiconductor workpiece to separate locations of the camera.
6. The semiconductor workpiece ID reader as in claim 1 wherein the optical assembly guides the optical paths from the top and the bottom sections of the semiconductor workpiece to a superimposed location of the camera.
7. The semiconductor workpiece ID reader as in claim 1 wherein the enclosure covers the optical paths of the optical assembly essentially blocking out ambient light from reaching the camera.
8. The semiconductor workpiece ID reader as in claim 1 , wherein the adjustable light source is configured to adjust one or more of the intensity, wavelength and direction of the illumination of the top and bottom sections based on an ID mark on the semiconductor workpiece.
9. A semiconductor workpiece ID reader comprising:
a camera configured to receive images from a top section and a bottom section of a semiconductor workpiece disposed within an opening of the semiconductor workpiece ID reader, wherein the top section and the bottom section each comprise a portion of a peripheral edge of the semiconductor workpiece, wherein the top section and the bottom section are substantially smaller than the whole semiconductor workpiece;
a light source configured to illuminate only a portion of the top section of the semiconductor workpiece and only a portion of the bottom section of the semiconductor workpiece;
a first optical assembly to guide a first pathway from only a portion of the top section of the semiconductor workpiece to the camera;
a second optical assembly to guide a second pathway from only a portion of the bottom section of the semiconductor workpiece to the camera; and
wherein the optical assemblies are disposed to receive images of both the portion of the top section and the portion of the bottom section of the semiconductor workpiece from a substantially normal angle with respect to the semiconductor workpiece and the camera is configured to image both the portion of the top section and the portion of the bottom section of the semiconductor workpiece so that a portion of an ID mark on the semiconductor workpiece is defined from specular features of both the top section and the bottom section of the semiconductor workpiece forming respective images of the portion of the top section and the portion of the bottom section with the semiconductor workpiece located at more than one different heights within the opening of the semiconductor workpiece ID reader and the specular features of both the top section and the bottom section of the semiconductor workpiece reaching the camera shielded from environment lighting, by the opening, with the semiconductor workpiece at each of the different heights within the opening of the semiconductor workpiece ID reader.
10. The semiconductor workpiece ID reader as in claim 9 wherein the light source is configured to illuminate the top and the bottom sections of the semiconductor workpiece at a substantially normal angle.
11. The semiconductor workpiece ID reader as in claim 9 wherein the light source is configured to illuminate the top and the bottom sections of the semiconductor workpiece at a slant angle.
12. The semiconductor workpiece ID reader as in claim 9 wherein the light source is configured to illuminate the top and the bottom sections of the semiconductor workpiece at a substantially normal angle and at a slant angle.
13. The semiconductor workpiece ID reader as in claim 9 wherein the optical assemblies guide the first and second pathways from the top and the bottom sections of the semiconductor workpiece to separate locations of the camera.
14. The semiconductor workpiece ID reader as in claim 9 wherein the optical assemblies guide the first and second pathways from the top and the bottom sections of the semiconductor workpiece to a superimposed location of the camera.
15. A semiconductor workpiece ID reader comprising;
a camera;
a prism assembly having an opening, wherein the opening is configured to enable light from a top section and a bottom section of a semiconductor workpiece to reach the camera shielded from environmental lighting, wherein the top section and the bottom section each comprise a portion of a peripheral edge of the semiconductor workpiece, and wherein the top section and the bottom section are substantially smaller than the whole semiconductor workpiece; and
a light source configured to illuminate only a portion of the top section of the workpiece and only a portion of the bottom section of the semiconductor workpiece; and
wherein the camera is configured to image both the portion of the top section and the portion of the bottom section of the semiconductor workpiece so that a portion of an ID mark on the semiconductor workpiece is defined from specular features of both the top section and the bottom section of the semiconductor workpiece forming respective images of the portion of the top section and the portion of the bottom section with the semiconductor workpiece located at more than one different heights within the opening of the prism assembly and the specular features of both the top section and the bottom section of the semiconductor workpiece reaching the camera shielded from the environmental lighting with the semiconductor workpiece at each of the different heights within the opening of the prism assembly.
16. The semiconductor workpiece ID reader as in claim 15 wherein the light source is configured to illuminate the top and the bottom sections of the semiconductor workpiece at a substantially normal angle.
17. The semiconductor workpiece ID reader as in claim 15 wherein the light source is configured to illuminate the top and the bottom sections of the semiconductor workpiece at a slant angle.
18. The semiconductor workpiece ID reader as in claim 15 wherein the light source is configured to illuminate the top and the bottom sections of the semiconductor workpiece at a substantially normal angle and at a slant angle.
19. The semiconductor workpiece ID reader as in claim 15 further comprises an optical assembly for directing images from the top and the bottom sections of the semiconductor workpiece to separate locations of the camera.
20. The semiconductor workpiece ID reader as in claim 15 further comprises an optical assembly for directing images from the top and the bottom sections of the semiconductor workpiece to a superimposed location of the camera.
21. The semiconductor workpiece ID reader as in claim 15 further comprising an enclosure covering the prism assembly.