TW201440939A - Method for cutting glass panel using laser beam - Google Patents

Abstract

A method for cutting a glass panel is provided, which utilizes laser beams to cut the glass panel for forming at least one workpiece. The method includes performing the following steps (a) to (c) in sequence: (a) scribing a plurality of straight scores on a surface of the glass panel by using a first laser beam, and the straight scores define the size of workpiece; (b) cutting the glass panel along the straight scores scribed by the first laser beam by using a second laser beam, thereby obtaining the workpiece; (c) processing a corner of the workpiece by using a third laser beam. The first laser beam and the third laser beam are short-pulse lasers.

Description

Method of cutting a glass panel using a laser beam

This invention relates to a glass panel cutting technique and, more particularly, to a method of cutting a glass panel using a laser beam.

In today's life, there is an increasing demand for mobile communication products. According to estimates by DIGITIMES Research, global smartphone shipments will grow by 30% in 2013 to 865 million, and the proportion of smart phones in total mobile phone shipments will rise to 43.9. %, showing its development potential.

For high-end communication products such as smart phones, touch panels made of high-strength glass materials are one of the most important components. In the field of touch panels, especially when applied to smart phones, the size of the glass substrate used is about 370 mm x 470 mm and the thickness is from 0.4 mm to about 1 mm, and is used in panel manufacturing. The glass substrate can be cut into rectangular panels of about 4 to 6 inches according to requirements.

In the known tempered glass cutting technology, there is a direct diamond cutter The method of cutting. However, the section formed by cutting a glass panel (substrate) with a diamond cutter is extremely rough and forms many debris or cracks in the section. In order to solve such problems, some methods of using a laser beam for glass panel cutting have also been proposed.

However, in the past, cutting with high-infiltration diamond cutter wheels, laser scribing or laser ablation has been easy to produce (1) poor quality of the cut section, (2) It is necessary to carry out subsequent edging processing, and (3) insufficient strength of the glass, and it is difficult to achieve high-quality cutting. In addition, in terms of the thermal splitting process using lasers, although nearly perfect cutting sections can be provided, the control of the process is very difficult due to the complicated stress field formed by the laser. Generally, the cutting in the first axial direction is relatively easy to complete; however, after the panel or the substrate is rotated by 90 degrees, when the second axial cutting is to be performed, the perfect cutting section of the first axial direction must be crossed, and it is difficult to smoothly cut. The yield is extremely low, especially when it comes to brittle materials with high hardness, the thermal cracking process is more difficult.

In addition, for the large-scale process of the high-priced one-piece glass touch panel (OGS), since the glass surface already has a film layer, and the cutting process belongs to the latter step of the complete process, if the cutting process is generated, Any flaws will have a serious negative impact on production capacity and costs. Furthermore, if subsequent steps such as edging are performed, particulate swarf which may cause contamination or scratching on the glass surface may occur, which may not only be accompanied by an effective cleaning process, but may also result in poor surface quality of the panel.

On the other hand, the strength of the glass panel is also a required focus. If cutting When the micro-defects or cracks at the edge of the panel are generated during the edging process, stress concentration points are formed, and the strength of the glass panel is insufficient. When the glass panel is inadvertently impacted by an external force, it will follow the aforementioned micro-defects. split. Therefore, from the viewpoint of failure mechanics, it is known that the processing quality of the surface of the workpiece directly affects the fatigue strength and the flexural strength (or "fracture strength").

For brittle materials such as glass, the cutting section should avoid any tiny cracks, and the surface roughness of the section will directly affect its 3- or 4-point bending test. The strength measured in ). Taking tempered glass as an example, after cutting with a diamond cutter wheel, the strength is only tens of MPa, the high-quality laser peeling section is about 200 MPa, and the intensity of the laser-scored re-splitter is also equivalent; The strength can reach more than 600 MPa, but ideally, the strength of the reinforced glass section should be 800 MPa. Therefore, how to improve the quality of the processed section to achieve better glass strength is also an important issue.

In recent years, there has been a growing demand for panel cutting technology. However, in the field of glass panel cutting processing, mature and stable laser cutting technology and equipment have not yet been developed. In order to effectively improve the processing efficiency, the ideal glass panel cutting technology is needed.

In view of this, the present invention provides a method of cutting a glass panel, which utilizes multiple laser beams to perform combined processing on the glass panel, thereby being effective Improve the processing speed, improve the processing quality, and improve the yield of the product. This method is especially suitable for the cutting of tempered glass as a touch panel.

In the method of cutting a glass panel of the present invention, the glass panel is cut by a laser beam to form at least one workpiece, and the method comprises the following steps (a) to (c) in sequence. First, in the step (a), a plurality of straight scratches are drawn on the surface of the glass panel by the first laser beam, and the straight line scratches define the size of the workpiece; in the step (b), The two laser beams are cut along a straight line scratched by the first laser beam to obtain a workpiece; and then, in the step (c), the corner of the workpiece is processed by the third laser beam; The first laser beam and the third laser beam are short pulsed lasers.

In an embodiment of the invention, the third laser beam performs a non-linear processing on a corner of the workpiece.

In an embodiment of the invention, the third laser beam rounds the corners of the workpiece.

In an embodiment of the invention, the first laser beam is a yttrium aluminum garnet (YAG) laser and has a wavelength of 1064 nm, 532 nm, 355 nm or 266 nm.

In an embodiment of the invention, the first laser beam has a pulse time of 50 nanoseconds (ns) to 1 picosecond (ps).

In an embodiment of the invention, the first laser beam has a pulse time of 100 ps to 5 ps.

In an embodiment of the invention, the second laser beam is a CO ₂ laser beam having a wavelength of 10.6 μm.

In an embodiment of the invention, the power of the second laser beam is in the range of 20 W to 240 W.

In an embodiment of the invention, the power of the second laser beam is in the range of 30 W to 80 W.

In an embodiment of the invention, the spot shape of the second laser beam is a line shape, and the spot shape has a width of 0.2 mm to 0.8 mm and a length of 5 mm to 50 mm.

Based on the above, the method of cutting a glass panel of the present invention can significantly improve the processing efficiency of the glass panel, improve the quality of the cutting process, and improve the yield of the target product (workpiece).

The above described features and advantages of the invention will be apparent from the following description.

100‧‧‧glass panel

102, 102a, 102b‧‧‧ Straight line scratches

104, 104a‧‧‧ workpiece

106‧‧‧ corner

D‧‧‧depth

h‧‧‧Width

R‧‧‧ radius of curvature

S100, S200, S300‧‧‧ steps

1 is a flow chart of a method of cutting a glass panel in accordance with an embodiment of the present invention.

2 is a schematic view and a partial enlarged view of a scratch using a first laser beam in a method of cutting a glass panel according to an embodiment of the invention.

3 is a schematic view of cutting using a second laser beam in a method of cutting a glass panel in accordance with an embodiment of the present invention.

4 is a view of a method of cutting a glass panel according to an embodiment of the present invention, A schematic diagram of the third laser beam for corner processing.

Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. It should be noted that the present invention may be embodied in many different forms and is not limited to the embodiments described herein. For the sake of clarity in the drawings, the size and relative dimensions of the various components may be exaggerated. In addition, the terms "xy plane" and "substantially parallel to the x-axis" mentioned in the following embodiments are merely referring to the arrangement orientation of the additional drawings in order to explain the embodiments, and not to limit the present. invention.

1 is a flow chart of a method of cutting a glass panel in accordance with an embodiment of the present invention. Referring first to Figure 1, in the method of cutting a glass panel of the present invention, the glass panel is cut with a laser beam to form at least one workpiece. The cutting method comprises the following steps (a) to (c): (a) drawing a plurality of straight scratches on the surface of the glass panel with the first laser beam, and the straight lines define the workpiece Dimensions (step S100); (b) cutting the second laser beam along the straight line scratches drawn by the first laser beam to obtain a workpiece (step S200); (c) third laser The beam processes the corners of the workpiece (step S300). Wherein, the first laser beam and the third laser beam are short pulse lasers.

2 to 4 are schematic diagrams showing the steps of a method of cutting a glass panel according to an embodiment of the invention. Hereinafter, the embodiment shown in FIGS. 2 to 4 will be combined with FIG. 1 to further explain the method of cutting a glass panel of the present invention.

Referring first to FIG. 2, step S100 is performed to use the first laser beam (not drawn A plurality of straight scratches 102 are drawn on the surface of the glass panel 100, and the straight scratches 102 define the dimensions of the desired workpiece. The glass panel 100 can be a tempered glass for a general panel, such as a tempered glass used for a touch panel of a smart phone or a tablet computer, or an OGS panel that is close to a finished product, and the type and shape thereof are not particularly limited. .

The first laser beam used in step S100 is a short pulse laser, whereby extremely shallow scratches can be formed on the surface of the glass panel 100 by laser peeling. The term "laser stripping" refers to a technique of irradiating a surface of a surface with a laser beam to sublimate the surface material. In general, under low-energy laser irradiation, the material is heated and volatilized by absorbing laser energy; under high-energy laser irradiation, the material is rapidly converted into plasma. In the present invention, the use of a short pulse laser for laser stripping refers to the use of a pulsed laser beam to remove material rather than a continuous wave laser beam. Among them, the quality of a single laser pulse can be eliminated, depending on the optical properties of the material and the laser energy.

The first laser beam is, for example, a yttrium aluminum garnet (YAG) laser, but is not limited thereto. In addition, the short pulse laser described above refers to a laser having a pulse time (or pulse length) in the range of about 100 nanoseconds (ns) to 1 picosecond (ps). Specifically, the pulse time of the first laser beam is preferably 50 nanoseconds (ns) to 1 picosecond (ps), and particularly preferably 100 ps to 5 ps. In addition, the first laser beam may have a wavelength of 1064 nm or a multiple of it, such as 532 nm, 355 nm, or 266 nm. Among them, it is preferable to use a YAG laser having a wavelength of 1064 nm as the first laser beam. By selecting the wavelength The laser within the preferred range acts as the first laser beam, and the glass panel 100 can have a high absorption rate for the first laser beam, and can effectively achieve the purpose of peeling off the surface material. Further, in order to improve the accuracy of the scribing, it is preferable that the spot diameter of the first laser beam is small, for example, in the range of 10 μm to 20 μm.

In addition, in step S100, an inert gas (such as nitrogen or argon gas) may be used to pressurize the portion to be subjected to laser stripping to suppress light absorption around the portion or beam scattering during laser beam transmission. And blow away some of the material that is vaporized by the laser, thereby further improving the efficiency of laser stripping. The pressure value is not particularly limited, and those skilled in the art can adjust it according to actual needs.

As shown in FIG. 2, in this embodiment, the straight line scratch 102 is composed of a plurality of straight line scratches 102a and straight line scratches 102b, but is not limited thereto. Here, by forming a plurality of straight scratches 102a substantially parallel to the x-axis and a plurality of straight scratches 102b substantially parallel to the y-axis on the xy plane of the glass panel 100, it is possible to define a plurality of the same length and width dimensions. Rectangular area. The order and manner of forming the straight line scratches 102 are not particularly limited. For example, each of the straight line scratches 102a may be formed on the glass panel 100, and then the straight line scratches 102b may be formed. It should be understood by those of ordinary skill in the art that the order of the scratches can be determined depending on the arrangement of the laser light source, the relative position of other mechanisms, and the like.

The depth d of the straight line scratch 102 is, for example, much smaller than 1/3 or 1/4 of the thickness of the target workpiece, and is about 1/10 to 1/20 of the thickness of the workpiece, and the width h thereof is, for example, controlled below 30 μm. . In general, in traditional laser scratching techniques, the scratch depth often needs to be about 120 μm, or must be as deep as 1/3 of the target workpiece thickness. 1/4, and the mechanical splitting process is required to ensure the manufacturing yield, and after the splitting, it is still necessary to match the edging to ensure the quality of the section, and the required steps are complicated and time consuming. In the present invention, faster laser scratch processing can be realized by further effectively controlling the depth and width of the straight line scratches within the above preferred range.

Next, referring to FIG. 3, step S200 is performed to cut the second laser beam (not shown) along the straight scratch 102 drawn by the first laser beam to obtain the workpiece 104. Here, the second laser beam is cut along the scratches drawn by the first laser beam in a thermal cracking manner, so that the glass panel 100 is broken along the straight line, so that the long and short sides of the workpiece 104 can be completed. Straight line cutting. The order of cutting is, for example, first cutting the glass panel 100 in the first axial direction (x-axis), cutting the glass panel 100 along a straight line parallel to the x-axis, and then rotating the glass panel 100 by 90 degrees. Then, the second axial (y-axis) cutting is performed, and the glass panel 100 is cut along a straight line parallel to the y-axis.

The so-called thermal cracking method is performed by using a material having a high absorption characteristic of light of a specific wavelength to perform cutting, and thus generally can be performed using a low-power carbon dioxide laser beam. The laser beam mechanism is used to focus the laser beam on the surface of the material to be cut and form an appropriate stress field with appropriate cooling effects to control the crack formation and growth rate to complete the material cutting. The above cooling effect is achieved by directly spraying a water stream onto the glass surface at the end of the CO ₂ laser beam heating spot, and the pressure of the water-air mixed fluid is maintained at about 2.5 kg/cm ² .

Specifically, the second laser beam used in the present invention is, for example, a CO ₂ laser beam having a wavelength of 10.6 μm. The cutting speed of the second laser beam depends on factors such as the material of the glass, the depth of the scratch, and the laser power, for example, in the range of about 20 mm to 500 mm per second, but is not limited thereto. If the depth of the straight line of the first laser beam is deeper, the cutting speed of the second laser beam is higher; if the straight line of the first laser beam is shallower, the cutting section of the second laser beam is The better the quality. Further, the power of the second laser beam is preferably in the range of 20 W to 240 W, more preferably in the range of 30 W to 80 W.

The spot shape of the second laser beam is, for example, a line type, and the width of the spot shape is preferably 0.2 mm to 0.8 mm, and the length thereof is preferably 5 mm to 50 mm. In this cutting step, by using a laser beam having such a spot shape as the second laser beam, the quality of the cut surface can be remarkably improved, which is preferable.

Finally, referring to FIG. 4, step S300 is performed. The corners 106 of the workpiece 104 are processed by a third laser beam (not shown). The corners here refer to the corners formed by the two sides of the workpiece that intersect. In the present embodiment, the four corners 106 of the rectangular workpiece 104 are processed, but in fact, those skilled in the art can determine whether to process the respective corners of the workpiece according to requirements.

The third laser beam used here is also a short-pulse laser. In fact, the same laser beam as the first laser beam can be used as the third laser beam due to its laser source type, pulse time, and wavelength range. The preferred embodiment and mode of operation have been described in detail above, and thus will not be described again. It should be noted that since the cutting path in this step is short, the third laser beam can be applied in a direct cut manner, which is not exactly the same as the straight line scratch processing of the first laser beam described previously.

Specifically, the third laser beam is, for example, a non-linear processing of the four corners 106 of the workpiece 104. Here, the term "non-linear processing" refers to processing for forming a non-linear portion on a target workpiece (finished product), and specifically, round corner processing, round hole processing, hole processing, various curve processing, and the like are exemplified. .

In this embodiment, the third laser beam is rounded to each corner 106 of the workpiece 104. The dashed box in Fig. 4 shows a top view of the workpiece 104 before and after corner machining, wherein it can be clearly seen that the corner 106 of the workpiece 104a after being processed is rounded to a circle having a radius of curvature R. angle. The magnitude of the radius of curvature R is not particularly limited, and those skilled in the art can set it according to actual specifications.

In this step, by using the third laser beam, the corners of the glass are directly cut in a peeling manner to provide a more detailed cross section. Since it is not mechanically ground, it can avoid the generation of particulate chips due to mechanical grinding, so it is especially suitable for the processing of glass panels that are close to the finished product (such as the glass panel of OGS).

Hereinafter, application examples will be presented to specifically describe the method of cutting a glass panel proposed by the present invention.

Instance

In this example, the first laser beam is a PS-1064 from Photonics Industries, with a laser power of 45 Watt on average; the second laser beam is from a SLC140 CO ₂ laser source from GSI Group; The same laser source as the laser beam serves as the laser source for the third laser beam.

In this example, tempered glass with a original size of 370 mm x 470 mm x 0.55 mm was used as the glass panel with a Depth of Layer (DOL) of 40 μm. The target product is a rounded rectangular workpiece with a long and short side dimension of 11.0 mm x 5.5 mm and a corner diameter of approximately 10 mm, ie the corner arc length is approximately 8 mm.

First, according to the size of the finished workpiece, a very shallow straight line is scratched on the surface of the large glass panel with the first laser beam. In this pass, a YAG laser source with a wavelength of 1064 nm is used, and a wavelength beam multiplier can be used to provide laser beams of 532 nm, 355 nm, and 266 nm wavelengths. In this example, a laser beam with a wavelength of 1064 nm is used as the first laser beam, and its output power is about 10 W~65 W; the pulse energy is 5 μj~30 μj; the pulse duration is about 15 ps~25ps; the spot size is controlled at about 10 μm. By using this laser beam, the action of this pass can be completed in about 30 seconds to form a plurality of straight line scratches having a width of about 25 μm and a depth of about 50 μm. The size of the workpiece defined by the above scratches is, for example, 11.0 mm x 5.0 mm in the long and short sides, and about 6 long axis directions and 4 short axis directions are required. In another example, a laser beam with a wavelength of 355 nm is used as the first laser beam, and its output power is about 2 W~10 W; the pulse energy is 10 μj~30 μj; and the pulse duration is about 15 Ps~25ps; the spot size is controlled at about 10 μm. Thereby, a scratch having a depth of about 50 μm and a width of about 20 μm can be produced, which is more suitable for the subsequent processing of the second laser light, but the cost is high.

Next, using the second laser beam, the straight line of the long and short sides of the target workpiece is completed by thermal rupture according to the trajectory of the previous first straight line scratch. In this example, a CO ₂ laser with an output power of 20 W to 150 W is used and operated with an XY-θ rail working platform with an X-axis stroke of 800 mm and a Y-axis stroke of 600 mm for fast positioning. The speed is 1,000 mm/sec. In addition, the workpiece moves at speeds between 100 mm and 400 mm per second. The second laser beam is transmitted through the optical lens group and defocused on the surface of the glass panel to form a near-line type spot having a width of about 0.2 mm to 0.8 mm and a length of preferably 5 mm to 50 mm. By using this laser beam, the action of this pass can be completed in about 40 seconds.

In addition, it has been experimentally found that the cutting speed of this pass is positively correlated with the straight line scratch depth of the previous one. If the scratch depth is 30 μm, 50 μm, 100 μm, respectively, the panel cutting speed in this step is about They are 150 mm/sec, 300 mm/sec, and 500 mm/sec or more.

Finally, the third laser beam is used to complete the arc cutting of the four corners of the glass panel. In this pass, a YAG laser source with a wavelength of 1064 nm is used, and a wavelength beam multiplier can be used to provide laser beams of 532 nm, 355 nm, and 266 nm wavelengths. In this example, a laser beam with a wavelength of 1064 nm is used as the third laser beam, and its output power is about 10 W~65 W; the pulse energy is 5 μj~30 μj; the pulse duration is about 15 ps~25ps; the spot size is controlled at about 10 μm. In this pass, by using this laser beam, the arc cutting of four corners of a workpiece can be completed in about 8 to 12 seconds.

The method for cutting a glass panel of the present invention combines a first laser beam and a second laser beam to complete a straight line cutting process, which not only provides good cutting section quality, but also has a glass panel strength of more than 600 MPa; Third laser beam, Complete the arc processing of the corners of the panel glass, which can greatly improve the cutting speed. Compared with the most advanced pico second laser peeling cutting, it can save up to 50% of the cutting processing time (picosecond laser) The peeling and cutting generally takes about 40 seconds, and the cutting by the method of the present invention takes only about 20 seconds); and because the quality of the cut surface of the glass panel is excellent, the subsequent processing amount can be greatly reduced, or even no subsequent processing is required.

It can be seen from the above embodiments and examples that the method for cutting a glass panel of the present invention can significantly improve the chip and micro-crack which may be caused by the diamond wheel cutter with the laser cutting, which may cause the panel to be defective. The problem. More specifically, the processing method of the present invention can greatly reduce the occurrence of defects such as fine cracks, and the processing section is almost perfect, so that the highest strength of the glass panel can be retained. Furthermore, the section quality can be further improved by processing the corner portions by laser. Compared with the conventional mechanical grinding method, the process has high cleanliness and can effectively reduce the manufacturing cost.

In summary, the method for cutting a glass panel of the present invention can at least significantly improve the processing efficiency of the glass panel, improve the quality of the cutting process, and greatly improve the yield of the target product (workpiece).

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

S100, S200, S300‧‧‧ steps

Claims (10)

A method of cutting a glass panel, using a laser beam to cut a glass panel to form at least one workpiece, the method comprising sequentially performing the following steps (a) to (c): (a) using a first laser The light beam draws a plurality of straight scratches on the surface of the glass panel, and the linear scratches define the size of the workpiece; (b) a second laser beam is drawn along the first laser beam The straight line scratches are cut to obtain the workpiece; and (c) the corner of the workpiece is processed by a third laser beam; wherein the first laser beam and the third laser beam are short Pulsed laser. The method of cutting a glass panel according to claim 1, wherein the third laser beam performs a non-linear processing on a corner of the workpiece. The method of cutting a glass panel according to claim 2, wherein the third laser beam is rounded to a corner of the workpiece. The method of cutting a glass panel according to claim 1, wherein the first laser beam is a yttrium aluminum garnet (YAG) laser and has a wavelength of 1064 nm, 532 nm, 355 nm or 266 nm. The method of cutting a glass panel according to claim 1, wherein the first laser beam has a pulse time of 50 ns to 1 ps. The method of cutting a glass panel according to claim 5, wherein the first laser beam has a pulse time of 100 ps to 5 ps. The method of cutting a glass panel according to claim 1, wherein the second laser beam is a CO ₂ laser beam having a wavelength of 10.6 μm. The method of cutting a glass panel according to claim 1, wherein the power of the second laser beam is in the range of 20 W to 240 W. The method of cutting a glass panel according to claim 8, wherein the power of the second laser beam is in the range of 30 W to 80 W. The method of cutting a glass panel according to claim 1, wherein the spot shape of the second laser beam is a line shape, and the spot shape has a width of 0.2 mm to 0.8 mm and a length of 5 mm to 50 mm. .