Eccentric abrasive wheel for wafer processing

• US 20020102920A1
• Filed: 04/30/2001
• Published: 08/01/2002
• Est. Priority Date: 01/26/2001
• Status: Active Grant

• Current Assignee: Wafer Solutions Incorporated
• Original Assignee: Wafer Solutions Incorporated
• Inventors: Vogtmann, Michael, Wisnieski, Michael, Vepa, Krishna
• Granted Patent: US 6,672,943 B2
• Time in Patent Office: Days
• US Class Current: 451/41
• CPC Class Codes: B24B 7/228 for grinding thin, brittle parts, e.g. semiconductors, wafers grinding edges of thin, brittle parts B24B9/065
• CPC Class Codes: B24D 7/06 with inserted abrasive blocks, e.g. segmental
• CPC Class Codes: H01L 2223/54493 Peripheral marks on wafers, e.g. orientation flats, notches, lot number

Abstract

The present invention provides exemplary methods, systems and apparatus that provide improved substrate characteristics after grinding operations by avoiding or reducing overgrind damage to the wafers. In one embodiment, a grinding apparatus (100) includes a first spindle (110) having an eccentric-shaped abrasive matrix (112) coupled thereto and a second spindle (116) adapted to hold a substrate (118) to be ground. The second spindle is offset from said first spindle such that the abrasive matrix passes through the substrate surface center (134) for only a portion of the time during grinding operations.

Claims

1. An apparatus for grinding a substrate, said apparatus comprising:

a first spindle having an eccentric-shaped abrasive matrix coupled thereto; and

a second spindle adapted to hold a substrate to be ground, said second spindle offset from said first spindle.

2. The apparatus as in claim 1 further comprising a rotation device for rotating said first and second spindles.

3. The apparatus as in claim 1 wherein said first and second spindles are adapted to rotate such that said abrasive matrix passes through a center of said substrate only a portion of the time during which said first spindle completes a 360 degree rotation.

4. The apparatus as in claim 1 wherein said first spindle has a circular shaped surface to which said eccentric-shaped abrasive matrix is coupled.

5. The apparatus as in claim 1 wherein said first spindle has an elliptical shaped surface to which said abrasive matrix is coupled, said matrix coupled near an edge of said elliptical shaped surface.

6. The apparatus as in claim 1 wherein said abrasive matrix comprises a diamond bit pattern.

7. The apparatus as in claim 1 further comprising a translation device coupled to said first spindle and adapted to translate said first spindle in a back and forth motion.

8. The apparatus as in claim 1 further comprising a translation device coupled to said second spindle and adapted to translate said second spindle in a back and forth motion.

9. The apparatus as in claim 1 wherein said eccentric-shaped abrasive matrix is selected from an elliptical shape and an oval shape.

10. The apparatus as in claim 1, wherein said eccentric-shaped abrasive matrix further comprises a random abrasive matrix pattern.

15. A method of grinding a substrate, said method comprising:

providing an apparatus as in claim 1;

positioning said spindles such that said abrasive matrix is in contact with a surface of said substrate; and

simultaneously rotating said first and second spindles so that said abrasive matrix contacts said substrate surface, said abrasive matrix passing through a center of said substrate surface for only a portion of a time said spindles are rotating.

11. A substrate grinding apparatus, comprising:

a first spindle having an abrasive matrix coupled to a first surface of said spindle, said first spindle having a first axis of rotation; and

a second spindle adapted to hold a substrate to be ground, said second spindle having a second axis of rotation;

wherein said abrasive matrix has a non-circular pattern.

12. The substrate grinding apparatus as in claim 11 wherein said first and second axii of rotation are generally parallel, and said first spindle is offset from said second spindle.

13. The substrate grinding apparatus as in claim 11 wherein said first and second spindles are adapted to rotate such that said abrasive matrix passes through a center of said substrate only a portion of the time during which said first spindle completes a 360 degree rotation.

14. The substrate grinding apparatus as in claim 11 wherein said abrasive matrix comprises a random pattern abrasive matrix.

16. The method of grinding according to claim 15 further comprising translating said first spindle in a back and forth motion while said abrasive matrix is in contact with said surface.

17. The method of grinding according to claim 16 wherein said translating occurs simultaneous with said rotating said first and second spindles.

18. The method of grinding according to claim 15 wherein said first spindle has a circular shaped surface to which said eccentric-shaped abrasive matrix is coupled.

19. A method of grinding a substrate, said method comprising:

providing a substrate grinder comprising;

a first spindle having an abrasive matrix coupled thereto, said first spindle having a first axis of rotation; and

a second spindle adapted to hold a substrate to be ground, said second spindle having a second axis of rotation;

positioning said spindles such that at least a portion of said abrasive matrix is in contact with a substrate surface to be ground;

simultaneously rotating said first and second spindles so that said abrasive matrix contacts said substrate surface; and

translating said first spindle so that said abrasive matrix passes through a center of said substrate surface for only a portion of a time said first and second spindles are rotating.