Micro laser assisted machining

• US 8,933,366 B2
• Filed: 09/28/2005
• Issued: 01/13/2015
• Est. Priority Date: 09/28/2005
• Status: Active Grant

• Current Assignee: The Board of Trustees of Western Michigan University
• Original Assignee: Western Michigan University
• Inventors: Patten, John
• Primary Examiner(s): Coleman, William D
• Application Number:
  US11/992,811
• Publication Number:
  US 20100065536A1
• Time in Patent Office: 3,394 Days
• Field of Search: 219/78.01, 219/78.22, 219/86.23, 219/221, 219/121.66
• US Class Current: 219/121.66
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B23K 2103/52 Ceramics
• CPC Class Codes: B23K 26/0093 combined with mechanical machining or metal-working covered by other subclasses than B23K combined welding or cutting procedures or apparatus B23K28/02
• CPC Class Codes: B23K 26/037 by pressing on the workpiece, e.g. pressing roller foot
• CPC Class Codes: B23K 26/064 by means of optical elements, e.g. lenses, mirrors or prisms
• CPC Class Codes: B23K 26/364 for making a groove or trench, e.g. for scribing a break initiation groove
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: B23P 25/006 Heating the workpiece by laser during machining
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 2203/0195 Tool for a process not provided for in H05K3/00, e.g. tool for handling objects using suction, for deforming objects, for applying local pressure
• CPC Class Codes: H05K 2203/0271 Mechanical force other than pressure, e.g. shearing or pulling
• CPC Class Codes: H05K 3/0029 of inorganic insulating material
• CPC Class Codes: Y10T 29/51 Plural diverse manufacturing apparatus including means for metal shaping or assembling

Abstract

A method and apparatus (1) for machining a semiconductor or ceramic workpiece (32) causes a portion of the workpiece to undergo high pressure phase transformation to form a high pressure phase transformation portion which has altered optical properties from the remainder of the workpiece. A laser is irradiated on the high pressure transformation portion to heat the high pressure transformation portion and cause it to soften and then the workpiece is plastically deformed, at smaller loads and forces, along the softened portion in order to accomplish the machining of the workpiece with a machining tool (21).

Claims

1. A method of deforming a workpiece or removing material from the workpiece, comprising the steps of:

applying pressure to a surface of the workpiece with a tip of a machining tool to cause a portion of the workpiece to undergo high pressure phase transformation to form a high pressure phase transformation portion having altered optical properties from the remainder of the workpiece;

irradiating the high pressure phase transformation portion of the workpiece with laser radiation which is transmitted through the machining tool and the remainder of the workpiece and reflected or absorbed by the high pressure phase transformation portion to heat the high pressure phase portion and cause it to soften; and

plastically deforming the workpiece along the softened high pressure phase transformation portion.

2. The method of claim 1, wherein the workpiece is a semiconductor.

3. The method of claim 1, wherein the workpiece is a ceramic.

4. The method of claim 1, wherein the laser radiation is IR light.

5. The method of claim 1, wherein the tip of the machining tool which causes the portion of the workpiece to undergo high pressure phase transformation is a diamond.

6. The method of claim 1, additionally comprising the step of focusing the laser radiation with a lens.

7. The method of claim 1, wherein the step of applying pressure to a surface of the workpiece includes applying a pressure at least equivalent to the hardness of the workpiece.

8. The method of claim 5, additionally comprising the step of coating at least a portion of the diamond with a gold film to help focus the laser radiation.

9. An apparatus for performing a high pressure phase transformation machining of a workpiece, comprising:

a machining tool holder;

a machining tool having a tip;

a force generating means for bringing the tip of the machining tool into contact with a portion of the workpiece at a pressure of at least the hardness of the workpiece wherein the portion of workpiece contacted with the tip of the machining tool is converted by the pressure of the tip of the machining tool into a high pressure phase transformation portion which has altered optional properties from the remainder of the workpiece;

a laser source for generating laser radiation which is transmitted through the machining tool to the high pressure phase transformation portion of the workpiece; and

means for effecting relative movement between the workpiece and the machining tool.

10. The apparatus of claim 9, additionally comprising a means for transmitting the laser radiation from the laser source to the machining tool.

11. The apparatus of claim 9, wherein the machining tool comprises a diamond.

12. The apparatus of claim 9, wherein at least a portion of the machining to coated with a metallic film for focusing the laser radiation.

13. The apparatus of claim 9, wherein a lens is provided between the laser source and the machining tool for focusing the laser radiation.

14. The apparatus of claim 9, additionally comprising a fiber optic cable for transmitting the laser radiation from the laser source to the machining tool.

15. An apparatus for performing high pressure phase transformation machining of a workpiece, comprising:

a machining tool holder;

a machining tool utilizing an optically transparent material;

a machine for bringing the machining tool into contact with a portion of the workpiece at a pressure of at least the hardness of the workpiece to convert the contacted portion of the workpiece into a high pressure phase transformation portion which has altered optical properties from the remainder of the workpiece and effecting relative movement between the workpiece and the machining tool; and

a source for generating laser radiation which is transmitted through the optically transparent material of the machining tool to the high pressure phase transformation portion of the workpiece.

16. The apparatus for performing high pressure phase transformation machining of claim 15, wherein a port on of the machining tool is coated with a film.

17. The apparatus for performing high pressure phase transformation machining of claim 15, wherein the optically transparent material is a diamond.

18. The apparatus for performing high pressure phase transformation machining of claim 15, wherein a lens is provided between the laser source and the machining tool for focusing the laser radiation at predetermined wavelengths.

19. The apparatus for performing high pressure phase transformation machining of claim 15, wherein the laser is a green laser.

20. The apparatus for performing high pressure phase transformation machining of claim 16, wherein the film is gold.