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Multi-Foci Laser Separation of Sapphire Wafers with Partial Thickness Scanning
With multi-foci laser cutting technology for sapphire wafer separation, the entire cross-section is generally scanned with single or multiple passes. This investigation proposes a new separation technique through partial thickness scanning. The energy effectivity and efficiency of the picosecond las...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9033070/ https://www.ncbi.nlm.nih.gov/pubmed/35457810 http://dx.doi.org/10.3390/mi13040506 |
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author | Lye, Celescia Siew Mun Wang, Zhongke Lam, Yee Cheong |
author_facet | Lye, Celescia Siew Mun Wang, Zhongke Lam, Yee Cheong |
author_sort | Lye, Celescia Siew Mun |
collection | PubMed |
description | With multi-foci laser cutting technology for sapphire wafer separation, the entire cross-section is generally scanned with single or multiple passes. This investigation proposes a new separation technique through partial thickness scanning. The energy effectivity and efficiency of the picosecond laser were enhanced through a two-zone partial thickness scanning by exploiting the internal reflection at the rough exit surface. Each zone spanned only one-third thickness of the cross-section, and only two out of three zones were scanned consecutively. A laser beam of 0.57 W and 50 kHz pulse repetition rate was split into 9 foci, each with a 2.20 μm calculated focused spot diameter. By only scanning the top two-thirds sample thickness, first its middle section then upper section, a cleavable sample could result. This was achieved with the lowest energy deposition at the fastest scanning speed of 10 mm/s investigated. Although with partial thickness scanning only, counter intuitively, the cleaved sample had a previously unattained uniform roughened sidewall profile over the entire thickness. This is a desirable outcome in LED manufacturing. As such, this proposed scheme could attain a cleavable sample with the desired uniformly roughened sidewall profile with less energy usage and faster scanning speed. |
format | Online Article Text |
id | pubmed-9033070 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-90330702022-04-23 Multi-Foci Laser Separation of Sapphire Wafers with Partial Thickness Scanning Lye, Celescia Siew Mun Wang, Zhongke Lam, Yee Cheong Micromachines (Basel) Article With multi-foci laser cutting technology for sapphire wafer separation, the entire cross-section is generally scanned with single or multiple passes. This investigation proposes a new separation technique through partial thickness scanning. The energy effectivity and efficiency of the picosecond laser were enhanced through a two-zone partial thickness scanning by exploiting the internal reflection at the rough exit surface. Each zone spanned only one-third thickness of the cross-section, and only two out of three zones were scanned consecutively. A laser beam of 0.57 W and 50 kHz pulse repetition rate was split into 9 foci, each with a 2.20 μm calculated focused spot diameter. By only scanning the top two-thirds sample thickness, first its middle section then upper section, a cleavable sample could result. This was achieved with the lowest energy deposition at the fastest scanning speed of 10 mm/s investigated. Although with partial thickness scanning only, counter intuitively, the cleaved sample had a previously unattained uniform roughened sidewall profile over the entire thickness. This is a desirable outcome in LED manufacturing. As such, this proposed scheme could attain a cleavable sample with the desired uniformly roughened sidewall profile with less energy usage and faster scanning speed. MDPI 2022-03-24 /pmc/articles/PMC9033070/ /pubmed/35457810 http://dx.doi.org/10.3390/mi13040506 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Lye, Celescia Siew Mun Wang, Zhongke Lam, Yee Cheong Multi-Foci Laser Separation of Sapphire Wafers with Partial Thickness Scanning |
title | Multi-Foci Laser Separation of Sapphire Wafers with Partial Thickness Scanning |
title_full | Multi-Foci Laser Separation of Sapphire Wafers with Partial Thickness Scanning |
title_fullStr | Multi-Foci Laser Separation of Sapphire Wafers with Partial Thickness Scanning |
title_full_unstemmed | Multi-Foci Laser Separation of Sapphire Wafers with Partial Thickness Scanning |
title_short | Multi-Foci Laser Separation of Sapphire Wafers with Partial Thickness Scanning |
title_sort | multi-foci laser separation of sapphire wafers with partial thickness scanning |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9033070/ https://www.ncbi.nlm.nih.gov/pubmed/35457810 http://dx.doi.org/10.3390/mi13040506 |
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