Laser cutting method

• US 20060113287A1
• Filed: 11/14/2005
• Published: 06/01/2006
• Est. Priority Date: 11/26/2004
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Sugama, Sadayuki, Iri, Junichiro, Inada, Genji, Nishiwaki, Masayuki
• Granted Patent: US 8,108,998 B2
• Time in Patent Office: Days
• US Class Current: 219/121.720
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/0853 Devices involving movement of the workpiece in at least in two axial directions, e.g. in a plane
• CPC Class Codes: B23K 26/364 for making a groove or trench, e.g. for scribing a break initiation groove
• CPC Class Codes: B23K 26/38 by boring or cutting
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: B23K 26/53 for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks
• CPC Class Codes: Y10T 29/49401 Fluid pattern dispersing device making, e.g., ink jet

Abstract

At least one exemplary embodiment is directed to a laser cutting method where a laser beam is condensed at internal points inside a substrate forming processing regions, and where the laser is swept along a cutting line, where the cutting line is associated with a recess on the substrate and where the recess can be formed contemporaneously with the formation of the processing regions.

Claims

1. A laser cutting method for cutting a workpiece by condensing a laser beam inside the workpiece to form an internal processing region therein, comprising the steps of:

forming the internal processing region by condensing the laser beam at a predetermined depth from the workpiece surface; and

forming a recessed portion contemporaneously using the laser beam at a position irradiated with the laser beam on the workpiece surface.

2. The laser cutting method according to claim 1, wherein the laser beam has a wavelength such that the laser beam passes through a laser beam receiving surface of the workpiece and enters the workpiece but does not exit from a back surface of the workpiece.

3. The laser cutting method according to claim 1, wherein the predetermined depth is a condensing position of the laser beam that forms an internal processing region that is not connected via a crack to the recessed portion when the recessed portion on the workpiece surface and the internal processing region inside the workpiece are contemporaneously formed.

4. The laser cutting method according to claim 1, wherein the internal processing region includes a plurality of processing regions formed inside the workpiece serially in a depth direction of the workpiece.

5. The laser cutting method according to claim 1, wherein the internal processing region includes a plurality of processing regions formed inside the workpiece serially from a position a first predetermined distance from a front surface of the workpiece to a position a second predetermined distance to the front surface of the workpiece.

6. The laser cutting method according to claim 1, wherein the recessed portion formed on the workpiece surface extends along a predetermined cutting line on the workpiece surface.

7. The laser cutting method according to claim 1, wherein the laser beam for forming the internal processing region is shifted relative to the workpiece along a predetermined cutting line on the workpiece surface.

8. The laser cutting method according to claim 1, further comprising:

applying an external force to the workpiece to generate a crack connecting the recessed portion on the workpiece surface with the internal processing regions, thereby substantially cutting the workpiece along a first direction.

9. The laser cutting method according to claim 8, further comprising:

applying a second external force to the workpiece to generate a crack connecting the recessed portion on the workpiece surface with the internal processing regions, thereby substantially cutting the workpiece in a second direction, wherein the second direction intersects the first direction, and where the workpiece is separated into a number of subpieces, wherein a substantial number of subpieces are cut from the workpiece.

10. The laser cutting method according to claim 9, wherein the first direction and the second direction are substantially orthogonal to each other.

11. The laser cutting method according to claim 10, further comprising:

identifying the subpieces not cut from the workpiece; and

applying a pressing force to the identified subpieces not cut from the workpiece, wherein the pressing force cuts the identified subpieces from the workpiece.

12. The laser cutting method according to claim 10, wherein the external force and the second external force are applied to the workpiece surface opposite the surface having the recessed portion.