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Xie X Z, Zhou C X, Wei X, Hu W, Ren Q L. Laser machining of transparent brittle materials: from machining strategies to applications. Opto-Electron Adv 2, 180017 (2019). doi: 10.29026/oea.2019.180017
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Review Open Access
Laser machining of transparent brittle materials: from machining strategies to applications
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Abstract
Transparent brittle materials such as glass and sapphire are widely concerned and applied in consumer electronics, optoelectronic devices, etc. due to their excellent physical and chemical stability and good transparency. Growing research attention has been paid to developing novel methods for high-precision and high-quality machining of transparent brittle materials in the past few decades. Among the various techniques, laser machining has been proved to be an effective and flexible way to process all kinds of transparent brittle materials. In this review, a series of laser machining methods, e.g. laser full cutting, laser scribing, laser stealth dicing, laser filament, laser induced backside dry etching (LIBDE), and laser induced backside wet etching (LIBWE) are summarized. Additionally, applications of these techniques in micromachining, drilling and cutting, and patterning are introduced in detail. Current challenges and future prospects in this field are also discussed.-
Keywords:
- transparent brittle materials /
- glass /
- sapphire /
- laser machining
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References
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Xie X Z, Zhou C X, Wei X, Hu W, Ren Q L. Laser machining of transparent brittle materials: from machining strategies to applications. Opto-Electron Adv 2, 180017 (2019). doi: 10.29026/oea.2019.180017
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Figure 1.
Mechanism of laser direct machining transparent brittle materials with long-pulse and ultrashort pulse. (a) Schematic diagram of long-pulse laser action. (b) Schematic diagram of ultrashort pulse laser. Figure reprinted with permission from ref.16, Springer-Verlag.
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Figure 2.
Laser scribing and breaking. (a) Laser scribing. (b) Mechanical breaking. Figure reprinted with permission from ref.17, Springer-Verlag.
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Figure 3.
Representation of laser stealth dicing sapphire wafer. (a) Schematic illustration of the process for slicing. A laser beam is focused on point inside the wafer to form a stealth dicing (SD) layer. (b) The separation process. Fixing the expanded film with the wafer adhered to the wafer on a two-dimensional platform, and the sapphire wafer is separated by applying an external force. (c) Commonly used multifocal optical system diagram. Figure reproduced from: (a), (b) ref.22, Chinese Journal of Lasers; (c) ref.23.
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Figure 4.
(a–d) The physical process of black color laser patterning of glass substrates. (e) Black laser pattern of glass substrate. Figure reproduced from: (a)–(d) ref.50, Optical Society of America.
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Figure 5.
(a) Schematic diagram of three-dimensional model. (b) Temperature variation of different Z positions. Figure reprinted with permission from ref.57, Elsevier Ltd.
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Figure 6.
Proposed mechanism of the glass cutting using 1064 nm laser irradiation. (a) Laser irradiates from the top. (b) Copper deposition on the underneath of the glass. (c) The deposited copper absorbs the laser energy and heats up the immediate glass region. (d) Removal of the molten glass. Figure reprinted with permission from ref.61, Springer-Verlag.
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Figure 7.
(a) Contours of the vapor volume fraction by simulation. (b) High-speed photography of cavitation bubble. Figure reproduced from ref.64.
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Figure 8.
Schematic illustration of the LIBWE process using near-infrared laser pulses with (a) a low repetition rate and (b) a high repetition rate. Figure reprinted with permission from ref.67, Elsevier Ltd.
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Figure 9.
(a) Experimental device for acquiring pressure signals. (b) The whole acquisition time of the pulse pressure signals. (c) The part of the pressure signals under single-pulse. Laser energy density of 90.94 J/cm2, solution concentration of 1 mol/L, pulse width of 100 ns, detection distance of 2 mm, laser repetition frequency of 2.5 kHz. Figure reproduced from ref.72.
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Figure 10.
Optical micrograph. (a) Microlens. (b) Y-shaped microfluidic channel. (c) The enlarged image of the channel formed by the microlens. Figure reprinted with permission from ref.73, Springer-Verlag.
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Figure 11.
(a) Internal diffraction 1D micro-grating fabricated with fs laser. (b) Internal diffraction 2D micro-grating fabricated with fs laser. Schemes for (c) a double-layer 1D micro-grating, and (d) a stitched double-layer grating. Figure reprinted with permission from ref.74, Springer-Verlag.
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Figure 12.
SEM images of details microchannels with reservoir ablated in borosilicate glass. (a) Channel with reservoir. (b) Channel. (c) Close-up of the channel. (d) Close-up of the bottom of the channel (Ra 100–150 nm). Figure reprinted with permission from ref.75, Springer-Verlag.
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Figure 13.
SEM micrograph. (a) Circle micro-through-hole array. (b) Triangle micro-through-hole array. (c) Enlarged image of tip angle of the triangle micro-hrough-hole. Figure reprinted with permission from ref.76, Springer-Verlag, Berlin Heidelberg.
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Figure 14.
(a, b) Shaped cutting parts of sapphire cutting samples. (c) Tempered glass. (d) Quartz glass. (e) Solar glass. Figure reproduced with permission from: (a, b) ref.77, 78. (c–e) ref.79, Applied Laser.
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Figure 15.
(a) SEM micrograph of the line-and-space pattern on fused silica observed at an inclined angle of 45°. (b) Confocal scanning laser microscopic picture of a grid pattern on fused silica. Figure reprinted with permission from ref.85, Springer-Verlag.
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Figure 16.
SEM images of crossed grating patterns on F2 glass fabricated at 248 nm with the two-grating interferometer with double exposure, 250 mJ/cm2 average fluence. First exposure (generating nearly vertical lines): 200 pulses. The number of pulses of the second exposure (nearly horizontal lines) is increasing from (a) to (d). Figure reprinted with permission from ref.91, Springer-Verlag Berlin Heidelberg.
