Sapphire alignment fixture

• US 20080028627A1
• Filed: 08/04/2006
• Published: 02/07/2008
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Gonzalez, Steve G., Mysore, Ananda V.
• Granted Patent: US 7,421,795 B2
• Time in Patent Office: Days
• US Class Current: 33/568
• CPC Class Codes: G01B 1/00 Measuring instruments characterised by the selection of material therefor
• CPC Class Codes: G01B 5/0004 Supports G01B5/025 takes precedence
• CPC Class Codes: G01B 5/25 for testing the alignment of axes

Abstract

A metrology system comprises a support structure, a fixture having a bottom surface resting on a surface of the support structure and moveable relative to the support structure, and a first measurement assembly for interacting with a workpiece held by the fixture to measure a characteristic of the workpiece. One of the bottom surface of the fixture and the surface of the support structure comprises sapphire, and the other of the bottom surface of the fixture and the surface of the support structure comprises a metal.

Claims

1. A metrology system comprising:

a support structure;

a fixture having a bottom surface resting on a surface of the support structure and moveable relative to the support structure; and

a first measurement assembly for interacting with a workpiece held by the fixture to measure a characteristic of the workpiece,

wherein one of the bottom surface of the fixture and the surface of the support structure comprises sapphire, and the other of the bottom surface of the fixture and the surface of the support structure comprises a metal.

2. The metrology system of claim 1, wherein the bottom surface of the fixture is detachable.

3. The metrology system of claim 1, further comprising a second measurement assembly for measuring a characteristic of a workpiece held by the fixture.

4. The metrology system of claim 3, wherein the workpiece includes a conical cavity, and the first and second measurement assemblies are adapted to measure an angle of taper of the conical cavity.

5. The metrology system of claim 1, wherein the workpiece comprises metal and a surface of the fixture abuts the workpiece and comprises sapphire.

6. The metrology system of claim 1, wherein the support structure comprises a base, a stage guide, and a stage.

7. The metrology system of claim 6, wherein the stage is adapted to move relative to the stage guide to position the workpiece and the fixture properly with respect to the first measurement assembly before the measurement assembly measures a characteristic of the workpiece.

8. The metrology system of claim 3, wherein the support structure comprises a base, a stage guide, and a stage.

9. The metrology system of claim 8, wherein the stage moves relative to the stage guide to position the workpiece and the fixture properly with respect to the second measurement assembly before the measurement assembly measures a characteristic of the workpiece.

10. The metrology system of claim 3, further comprising data acquisition logic to receive and process the characteristic measured by the first and second measurement assemblies.

11. A method for measuring a characteristic of a workpiece, comprising:

loading a workpiece into a fixture that rests on a support structure, wherein interfacing surfaces of the fixture and the support structure have a coefficient of friction in a certain range;

moving the workpiece and a first measurement assembly relative to each other so that the workpiece is aligned with the first measurement assembly;

moving a component of the first measurement assembly to contact the workpiece to obtain a first measurement of a characteristic of the workpiece, wherein when the component contacts the workpiece, the fixture is adapted to slide on the support structure in response to a force exerted on the workpiece and the fixture by the component; and

receiving and calculating the first measurement of the characteristic of the workpiece.

12. The method of claim 11, further comprising moving the workpiece and a second measurement assembly relative to each other so that the workpiece is aligned with the second measurement assembly;

and

moving a component of the second measurement assembly to contact the workpiece to obtain a second measurement of the characteristic of the workpiece, wherein when the component of the second measurement assembly contacts the workpiece, the fixture is adapted to slide on the support structure in response to a force exerted on the workpiece and the fixture by the component of the second measurement assembly.

13. The method of claim 12, further comprising receiving and calculating the second measurement of the characteristic of the workpiece.

14. The method of claim 11, wherein interfacing surfaces of the workpiece and the fixture have a coefficient of friction of less than about 0.15.

15. The method of claim 11, wherein interfacing surfaces of the fixture and the support structure have a coefficient of friction of less than about 0.15.

16. The method of claim 15, wherein one of the interfacing surfaces comprises sapphire and the other of the interfacing surfaces comprises a metal.

17. The method of claim 14, wherein one of the interfacing surfaces comprises sapphire and the other of the interfacing surfaces comprises a metal.

18. The method of claim 17, wherein the metal is a polished steel.

19. A metrology system comprising:

a support structure;

a fixture having a bottom surface resting on a surface of the support structure and moveable relative to the support structure; and

a first measurement assembly for interacting with a workpiece held by the fixture to measure a characteristic of the workpiece,

wherein a surface of the fixture that abuts the workpiece to hold the workpiece comprises sapphire.

20. The metrology system of claim 19, further comprising data acquisition logic to receive and process the characteristic measured by the first and second measurement assemblies.