Singulation of sapphire substrate with high aspect ratio internal modification by sub-nanosecond pulsed fiber laser

Yasuhiro Okamoto, Kenta Takahashi, Akira Okada

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Sapphire has been widely used for a substrate of high brightness LED, and it is important to reduce the edge damage in the singulation process of sapphire substrate for the high quality product and the cost reduction. In this study, the internal modification technique of sapphire substrate by a sub-nanosecond pulsed fiber laser of 180ps was experimentally investigated with a normal achromatic focusing lens of 20mm in focal length, and the possibility of singulation method with this internal modification technique was discussed. The laser beam of 180ps and 1060nm was focused in sapphire substrate of 0.4mm thickness by passing through the epitaxial layer grown on the top side, and the internal modification zone was generated from the satin-finished surface as the bottom side of sapphire substrate. A high aspect ratio modified line such as 5-10μm width and 200μm height was successfully performed by the laser irradiation from the epitaxial layer side. A sapphire wafer of 0.4mm thickness could be broken from the internal modified line with less damage of the epitaxial layer by sufficient smaller stress compared with the tensile strength of sapphire. The breaking strength and its dispersion became smaller with increasing the number of laser scanning.

Original languageEnglish
Title of host publicationICALEO 2012 - 31st International Congress on Applications of Lasers and Electro-Optics
Pages813-819
Number of pages7
Publication statusPublished - 2012
Event31st International Congress on Applications of Lasers and Electro-Optics, ICALEO 2012 - Anaheim, CA, United States
Duration: Sep 23 2012Sep 27 2012

Other

Other31st International Congress on Applications of Lasers and Electro-Optics, ICALEO 2012
CountryUnited States
CityAnaheim, CA
Period9/23/129/27/12

Fingerprint

Aluminum Oxide
Fiber lasers
Pulsed lasers
Sapphire
Aspect ratio
Substrates
Epitaxial layers
Laser beam effects
Cost reduction
Laser beams
Light emitting diodes
Luminance
Lenses
Tensile strength
Scanning
Lasers

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Okamoto, Y., Takahashi, K., & Okada, A. (2012). Singulation of sapphire substrate with high aspect ratio internal modification by sub-nanosecond pulsed fiber laser. In ICALEO 2012 - 31st International Congress on Applications of Lasers and Electro-Optics (pp. 813-819)

Singulation of sapphire substrate with high aspect ratio internal modification by sub-nanosecond pulsed fiber laser. / Okamoto, Yasuhiro; Takahashi, Kenta; Okada, Akira.

ICALEO 2012 - 31st International Congress on Applications of Lasers and Electro-Optics. 2012. p. 813-819.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Okamoto, Y, Takahashi, K & Okada, A 2012, Singulation of sapphire substrate with high aspect ratio internal modification by sub-nanosecond pulsed fiber laser. in ICALEO 2012 - 31st International Congress on Applications of Lasers and Electro-Optics. pp. 813-819, 31st International Congress on Applications of Lasers and Electro-Optics, ICALEO 2012, Anaheim, CA, United States, 9/23/12.
Okamoto Y, Takahashi K, Okada A. Singulation of sapphire substrate with high aspect ratio internal modification by sub-nanosecond pulsed fiber laser. In ICALEO 2012 - 31st International Congress on Applications of Lasers and Electro-Optics. 2012. p. 813-819
Okamoto, Yasuhiro ; Takahashi, Kenta ; Okada, Akira. / Singulation of sapphire substrate with high aspect ratio internal modification by sub-nanosecond pulsed fiber laser. ICALEO 2012 - 31st International Congress on Applications of Lasers and Electro-Optics. 2012. pp. 813-819
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