Systems and processes that singulate materials

• US 10,239,160 B2
• Filed: 09/21/2011
• Issued: 03/26/2019
• Est. Priority Date: 09/21/2011
• Status: Active Grant

• Current Assignee: Rayd LLC
• Original Assignee: Coherent Inc (Coherent Corp.)
• Inventors: Mielke, Michael, Srinivas, Ramanujapuram A., Booth, Tim, Wilbanks, Thor
• Primary Examiner(s): Abraham, Ibrahime A
• Assistant Examiner(s): Bae, Gyounghyun
• Application Number:
  US13/239,323
• Publication Number:
  US 20130068736A1
• Time in Patent Office: 2,743 Days
• Field of Search: 21912167, 21912168, 21912169, 21912172, 21912177, 21912176, 21912171, 438463, 438795
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B23K 2103/42 Plastics B23K2103/16 takes precedence
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 2103/52 Ceramics
• CPC Class Codes: B23K 2103/56 semiconducting semiconducting devices B23K2101/40
• CPC Class Codes: B23K 26/0006 taking account of the properties of the material involved B23K26/32, B23K26/40 take precedence
• CPC Class Codes: B23K 26/359 by providing a line or line pattern, e.g. a dotted break initiation line
• 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: C03B 33/0222 Scoring using a focussed radiation beam, e.g. laser
• CPC Class Codes: Y02P 40/57 Improving the yield, e-g- reduction of reject rates

Abstract

Systems and methods for material singulation. According to some embodiments, methods for material singulation may include applying a first laser output to the material, the first laser output causing a modification of a material property of the material when exposed to the first laser output; and applying a second laser output to the material that was exposed to the first laser output to cause singulation of the material in such a way that surfaces created by the singulation of the material are substantially free from defects.

Claims

1. A method for material singulation, the method comprising:

focusing a first laser output from a first laser device to a depth within a material, the depth being located between a top surface of the material and a bottom surface of the material, the focused first laser output having a beam width in the material, the first laser output comprising ultrafast laser pulses having a duration less than or equal to 50 picoseconds, the first laser output having a wavelength selected from near-infrared and visible wavelengths;

applying the focused first laser output to the material along a beam path, an electric field of the ultrafast lasers pulses in the focused first laser output causing rapid acceleration of electrons, the focused first laser output thereby causing a permanent change in refractive index, optical absorption, density, or mechanical stress of the material exposed to the focused first laser output while the material exposed to the focused first laser output remains in a solid phase; and

sequentially applying a second laser output from a second laser device to the material along and directly adjacent to the beam path, the second laser output heating the material or generating an acoustic shockwave in the material, thereby separating the material along the beam path while reducing impartation of defects into the material, the second laser output having a beam width larger than the beam width of the focused first laser output, the second laser output having a higher average power and a lower peak power relative to the first laser output.

2. The method according to claim 1, wherein the ultrafast laser pulses of the first laser output have a duration less than or equal to about one picosecond.

3. The method according to claim 1, wherein the material exposed to the first laser output is modified by any of:

separating molecular bonds in material lattice;

geometrical reorientation of molecular constituents; and

spatial movement of molecular species.

4. The method according to claim 1, wherein the second laser output heats the material and causes a discontinuous stress gradient in the material.

5. The method according to claim 1, wherein the second laser output comprises a wavelength selected from a range of three to fifty micrometers, inclusive.

6. The method according to claim 1, wherein the second laser output comprises a wavelength selected from a range of 0.78 to three micrometers, inclusive.

7. The method according to claim 1, wherein a laser pulse duration of the second laser output is greater than or equal to ten picoseconds.

8. The method according to claim 1, wherein the second laser output includes a continuous wave output.

9. The method according to claim 1, wherein the steps of applying the first laser output and applying the second laser output occur within a second.

10. The method of claim 1, wherein the applying the second laser output to the body that was exposed to the first laser output causes complete separation of the material into two or more pieces.

11. The method of claim 1, wherein the first laser output and the second laser output are performed by using a single motion control.

12. The method of claim 1, further comprising selectively adjusting an amount of electronic energy excitation by varying parameters of a laser device including a beam delivery speed and a beam energy level.

13. The method of claim 1, further comprising inspecting the material by applying a light.

14. The method of claim 1, wherein the second laser output comprises a wavelength in a range of 11 micrometers to 50 micrometers.