Micro Laser Assisted Machining

• US 20100065536A1
• Filed: 09/28/2005
• Published: 03/18/2010
• 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
• Granted Patent: US 8,933,366 B2
• Time in Patent Office: Days
• US Class Current: 219/121.660
• 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 machining a workpiece, comprising the steps of:

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

plastically deforming the workpiece along the softened high pressure 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 a diamond is used to cause the portion of the workpiece to undergo high pressure phase transformation.

6. 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.

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

8. The method of claim 1, wherein the portion of the workpiece is subjected to a pressure at least equivalent to the hardness of the workpiece.

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

a laser source for generating laser radiation;

a machining tool holder;

a machining tool capable of transmitting the laser radiation;

a force generating means for bringing the machining tool into contact with the workpiece at a pressure of at least the hardness 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 tool is 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.