Method and apparatus for positioning a wafer on a flat bed

Claim 3

The method set forth in claim 1 wherein the particular portion is aligned along a particular axis and wherein the position of the wafer is aligned along the particular axis in accordance with comparisons between the distinctive quality of the particular portion on that wafer and the distinctive quality of at least one portion displaced from the distinctive portion on the wafer.

Claim 4

The method set forth in claim 1 or 2 wherein the precision operation involves the testing of electrical circuitry on each die to determine if such electrical circuitry meets preselected standards.

Claim 5

The method set forth in claim 1 wherein the rotary position of the wafer is adjusted to dispose the rows of the dies on the wafer in a particular direction and wherein the precision operation is performed in sequence on electrical circuitry on the progressive dies on the wafer and wherein the precision operation involves the testing of the electrical circuitry on each die to determine if such circuitry meets preselected standards.

Claim 6

. A method of positioning a plurality of wafers on a flat bed to perform precision operations on the wafers where each of the wafers in the plurality has a plurality of printed dies disposed in at least one row, including the steps of: selecting a particular portion of a first wafer in the plurality with distinctive patterns of printed information in the particular portion to serve as a reference for positioning successive wafers in the plurality and determining the distinctive quality of such distinctive portion, comparing the distinctive qualities of portions of the reference wafer around the particular portion and intermediate the particular portion and the boundaries of the reference wafer to establish relatively low coincidence between the distinctive qualities of such particular portion and the intermediate portions, determining the relative difference in the distinctive quality of the patterns of the printed information between such particular portion and the intermediate portions to ensure that there is a relatively great difference in such distinctive qualities, comparing progressive portions of the reference wafer along a particular axis of the reference wafer with the particular portion to establish angular deviations of the reference wafer from such particular axis, and rotating the reference wafer in accordance with any angular deviations established by such comparisons.

Claim 7

. A method of positioning a plurality of wafers on a flat bed to perform precision operations on the wafers where each of the wafers in the plurality has a plurality of printed dies disposed in at least one row, including the steps of: selecting a particular portion of a first wafer in the plurality with distinctive patterns of printed information in the particular portion to serve as a reference for positioning successive wafers in the plurality and determining the distinctive quality of such distinctive portion, comparing the distinctive qualities of portions of the reference wafer around the particular portion and intermediate the particular portion and the boundaries of the reference wafer to establish relatively low coincidence between the distinctive qualities of such particular portion and the intermediate portions, determining the relative difference in the distinctive quality of the patterns of the printed information between such particular portion and the intermediate portions to ensure that there is a relatively great difference in such distinctive qualities, comparing progressive portions of the reference wafer along a particular axis of the reference wafer with the particular portion to establish angular deviations of the reference wafer from such particular axis, and rotating the reference wafer in accordance with any angular deviations established by such comparisons.

Claim 8

A method as set forth in claim 5, including the step of determining the particular displacement between the particular portion and a starting position on the reference wafer.

Claim 9

A method as set forth in claim 6, including the steps of: selecting, on each successive wafer after the first wafer, a distinctive portion having a distinctive quality corresponding substantially to the distinctive quality of the distinctive portion on the reference wafer, comparing the distinctive quality of progressive portions of each successive wafer with the distinctive quality of the distinctive portion to establish angular deviations of each such successive wafer from the particular axis, and rotating each such successive wafer to eliminate any such angular deviations.

Claim 10

A method as set forth in claim 7, including the step of sequentially testing each successive die on each wafer to determine if electrical circuitry printed on each die meets preselected standards.

Claim 13

The method set forth in claim 9, including the steps of: determining the displacement of the particular portion on the first wafer from a starting position, and displacing each successive wafer through such displacement after the alignment of the dies in the row on such wafer in the particular direction and before the performance of the precision operation on the dies in the row on such wafer.

Claim 14

11 . The method set forth in claim 10, including the steps of: training a camera at a particular position on the bed, and providing a visual scanning of the portion of the wafer being viewed by the camera at the particular position.

Claim 15

The method set forth in claim 9, including the steps of: training a camera at a particular position on the flat bed to produce signals representative of the image at each individual position in a selected area around the particular position, providing signals representative of the image at each individual position in the selected area, comparing the distinctive quality of the signals representative of the selected area and the distinctive quality of the particular portion, and using any differences in such comparison to adjust the position of the wafer relative to the camera to obtain optimal coincidence between the signals representative of the selected area and the particular portion.

Claim 16

In combination for positioning a plurality of wafers to perform precision operations on the wafer where each of the wafers in the plurality has a plurality of dies disposed in at least one row, a flat bed for holding the wafers; first means for scanning a selected portion on the flat bed and for producing signals representative of the image scanned at individual positions in the selected portion; second means for indicating the pattern of the signals representative of the image at the individual positions in a distinctive portion on a first wafer serving as a reference; third means responsive to the distinctive qualities of the relative patterns of the signals from the first and second means for shifting the position of the flat bed to maximize the coincidence of such distinctive qualities; and fourth means responsive to the distinctive qualities of the relative patterns of the signals provided by the first and second means upon progressive shifts of the flat bed in a particular direction for adjusting the flat bed in accordance with such relative patterns to align in the particular direction the dies in the row on the wafer.

Claim 17

In combination for positioning a plurality of wafers to perform precision operations on the wafer where each of the wafers in the plurality has a plurality of dies disposed in at least one row, a flat bed for holding the wafers; first means for scanning a selected portion on the flat bed and for producing signals representative of the image scanned at individual positions in the selected portion; second means for indicating the pattern of the signals representative of the image at the individual positions in a distinctive portion on a first wafer serving as a reference; third means responsive to the distinctive qualities of the relative patterns of the signals from the first and second means for shifting the position of the flat bed to maximize the coincidence of such distinctive qualities; and fourth means responsive to the distinctive qualities of the relative patterns of the signals provided by the first and second means upon progressive shifts of the flat bed in a particular direction for adjusting the flat bed in accordance with such relative patterns to align in the particular direction the dies in the row on the wafer.

Claim 18

The combination set forth in claim 13, including, the second means also indicating the displacement from a starting position of the distinctive image on the first wafer, the third means being responsive to the signals representing the displacement of the distinctive portion from the starting position for providing such displacement to the flat bed, and fifth means for providing the precision operation on the progressive dies on the wafer.

Claim 19

The combination set forth in claim 14, including, the first means including a camera and the second means including a memory and the third means including first and second motors for respectively moving the flat bed in first and second coordinate directions and the fourth means including a motor for rotating the flat bed.

Claim 20

16 . The combination set forth in claim 15 wherein the dies on the wafers on the flat bed have electrical circuitry printed on the dies and wherein the fifth means include a plurality of probes for testing the circuitry of the dies and the third means includes means for locating the distinctive area on each wafer and for then shifting the wafer to intermediate portions around the distinctive portions to identify the distinctive portion.

Claim 21

In combination for positioning a plurality of wafers to perform precision operations on the wafer where each of the wafers in the plurality has a plurality of dies disposed in at least one row, a flat bed for holding the wafers, first means for scanning a selected portion on the table and for producing electrical signals representing the pattern of the image on the dies of the wafer at the selected portion, second means responsive to-the electrical signals from the scanning means for operating upon such signals to provide an indication of the distinctiveness of the image on the dies at the selected portion, third means for obtaining a shifting of the flat bed relative to the scanning means in a preselected pattern to obtain a scanning by the viewing means of portions around the selected portion, the indicating means being responsive to each shift in the flat bed relative to the scanning means for operating upon the signals from the scanning means to provide an indication of the distinctiveness of the portion of the image on the dies at such shifted positions, the third means obtaining a shifting of the flat bed relative to the scanning means to progressive positions in a particular direction, the indicating means being responsive to each shift in the flat bed relative to the viewing means in the particular direction for determining any relative rotary displacement from the particular direction of the dies in the row on the wafer, and fourth means for rotating the flat bed in accordance with the determinations of the rotary displacement to align in the particular direction the dies in the row on the wafer.

Claim 22

In combination for positioning a plurality of wafers to perform precision operations on the wafer where each of the wafers in the plurality has a plurality of dies disposed in at least one row, a flat bed for holding the wafers, first means for scanning a selected portion on the table and for producing electrical signals representing the pattern of the image on the dies of the wafer at the selected portion, second means responsive to-the electrical signals from the scanning means for operating upon such signals to provide an indication of the distinctiveness of the image on the dies at the selected portion, third means for obtaining a shifting of the flat bed relative to the scanning means in a preselected pattern to obtain a scanning by the viewing means of portions around the selected portion, the indicating means being responsive to each shift in the flat bed relative to the scanning means for operating upon the signals from the scanning means to provide an indication of the distinctiveness of the portion of the image on the dies at such shifted positions, the third means obtaining a shifting of the flat bed relative to the scanning means to progressive positions in a particular direction, the indicating means being responsive to each shift in the flat bed relative to the viewing means in the particular direction for determining any relative rotary displacement from the particular direction of the dies in the row on the wafer, and fourth means for rotating the flat bed in accordance with the determinations of the rotary displacement to align in the particular direction the dies in the row on the wafer.

Claim 23

1 8. The combination set forth in claim 17, including, the first means including a camera and the second means including a memory and the third means including first and second motors for moving the flat bed in first and second coordinate directions and the fourth means including a third motor for rotating the flat bed.

Claim 24

The combination set forth in claim 17, including, means for obtaining a transfer of the progressive wafers in the plurality to the flat bed and the third and fourth means being operative to position each of the progressive wafers in the plurality for scanning of the selected portion on each of the wafers in the plurality by the first means.

Claim 25

The combination set forth in claim 19, including, the second means indicating the displacement of the selected portion on the wafer from a starting position and the third means providing a displacement of each progressive wafer to the starting position after the positioning of the flat bed to provide a scanning by the first means of the selected portion on each progressive die in the plurality.

Claim 26

The combination set forth in claim 20, including, the first means including a camera and the second means including a memory and the third means including first and second motors for moving the table in first and second coordinate directions and the fourth means including a third motor for rotating the table and the dies on each of the wafers having electrical circuitry printed on the dies, and means for testing the electrical circuitry on the progressive dies of each wafer after the positioning of the wafer to the starting position.