TWI460045B - Laser processing method and laser processing equipment - Google Patents

Description

Laser processing method and laser processing equipment

The invention relates to a laser processing method and a laser processing apparatus.

Tempered glass, such as Gorilla from Corning, USA, and tempered glass such as Dragontrail and Sodalime from Asahi, have been highly permeable and high-strength. Widely used in display devices.

Traditional glass cutting processes are often difficult to cut well on tempered glass. Traditional glass cutting mainly includes cutter wheel cutting, laser cutting and grinding rod grinding. Conventional cutter wheel cutting, laser cutting uses a cutter wheel or laser to form a cutting initiation opening or initial crack on the surface or inside of the glass, and then in the splitting process, the crack is extended between the upper and lower surfaces of the glass to completely cut the glass. . When cutting tempered glass by conventional cutter wheel cutting or laser cutting process, cracks often do not grow exactly in the expected path in the tempered layer due to the stress in the tempered layer of the tempered glass, or even completely not according to the expected path. Disordered growth, resulting in fragmentation and cutting failure. Grinding rod grinding is commonly used for cutting the closed area inside the glass. First drill a small hole with a drill bit and then grind it to the required size with a different grinding rod. When the tempered glass is cut by the grinding rod grinding process, the stress in the tempered layer of the tempered glass often causes undesired cracks during drilling and grinding. In addition, the wear bar is very worn and the efficiency is very low. Therefore, for tempered glass, such as tempered glass such as Gorilla, Sodalime, and Dragontrail, various conventional processing methods cannot effectively perform stable cutting. Now when cutting tempered glass, it is usually necessary to cut and grind the untempered glass before tempering. Rational, very inefficient.

Therefore, there is a need for a processing method and processing apparatus capable of effectively and stably cutting tempered glass such as tempered glass, such as Gorilla, Sodalime, and Dragontrail.

The laser cutting technology of the present invention is a heat removal cutting process using a laser source as an energy source. Specifically, the present invention utilizes the high power density output of the laser pulsed light at the condensing point to instantaneously vaporize or melt the material at the condensing point of the laser light, thereby achieving material removal. The material heat removal zone is connected laterally and longitudinally to form a cutting zone, thereby effecting the cutting and separation of the material. Its ultrashort pulse limits the thermal effect to a very small area near the focus, preventing the surrounding brittle material from bursting after being heated.

According to an aspect of the invention, there is provided a laser processing method comprising the steps of: illuminating a laser beam through an incident surface of the workpiece and concentrating light on or near a cutting start surface of the workpiece to cause a spotting point And/or processing the adjacent region of the concentrating spot to vaporize and/or melt, thereby forming an initial heat removal zone on the cutting initiation surface and causing the initial heat removal zone to follow a predetermined path on the cutting initiation surface Continuously distributed to form an initial heat removal line; illuminating the laser light to condense on or near the surface of the newly formed workpiece in the previous heat removal step, so that the processing gas at the condensing point and/or the vicinity of the concentrating point And/or melting to form a subsequent heat removal zone and to continuously distribute the subsequent heat removal zone along a predetermined path to form a subsequent heat removal line.

According to another aspect of the present invention, there is provided a laser processing apparatus for laser cutting a workpiece, comprising: a laser source adapted to emit laser pulsed light; a concentrating device capable of Radiating the laser pulsed light emitted by the laser source onto the surface or inside of the workpiece such that the power at the at least one spot is concentrated The density enables the workpiece to be vaporized and/or melted to form a heat removal zone; a moving device adapted to move the spotlight relative to the workpiece, the moving device being configured such that the spotlight is at Forming and/or melting the processed material at the condensing point and/or the vicinity of the condensing point on or near the cutting starting surface of the workpiece, thereby forming an initial heat removal zone on the cutting starting surface, And causing the initial heat removal zone to be continuously distributed along the predetermined path on the cutting initiation surface to form an initial heat removal line; such that the spotlight spot is on or near the surface of the newly formed workpiece in the previous heat removal step, The workpiece at the spotting point and/or the vicinity of the spotting point is vaporized and/or melted to form a subsequent heat removal zone and the subsequent heat removal zones are continuously distributed along a predetermined path to form a subsequent heat removal line.

The invention adopts the heat removal method to cut the tempered glass, avoids the splitting process in the traditional glass cutting process, avoids the disordered growth of the crack which is easy to occur in the tempered glass cutting, and leads to the failure of the cutting, thereby enabling the steel to be The glass is processed efficiently and stably.

The laser pulsed light cutting process of the present invention has many advantages over conventional processing methods:

(1) The processing range is not limited by the physical and mechanical properties of the material, and can process any hard, soft, brittle, heat-resistant or high-melting metal and non-metal materials.

(2) It is easy to process complex profiles, fine surfaces and flexible parts.

(3) It is easy to obtain good cutting section quality, cutting debris pollution, thermal stress, residual stress, cold work hardening, heat affected zone, etc. are relatively small.

(4) It is capable of cutting the tempered glass in the closed area and has extremely high stability.

(5) 3D dynamic scanning focus mirror and dual optical path system can greatly improve processing efficiency.

(6) Using laser light that can pass through the glass, always concentrating on the lower surface of the glass Or the lower surface formed by heat removal is processed, and the cutting residue is always under the laser cutting area, which does not affect the subsequent focusing of the laser light, and improves the laser processing efficiency. And can get a smooth, vertical, non-tapered cutting section.

(7) Under the tempered glass, a material capable of sputtering on the surface when irradiating the laser light, so that the sputtered material adheres to the lower surface of the glass during the cutting process, thereby increasing the glass to the laser. Absorption rate.

(8) The present invention employs a nanosecond, picosecond or femtosecond laser, which has a small pulse width and a small heat influence on the surrounding area, and can suppress the generation of microcracks.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

The laser cutting technology of the present invention is a heat removal cutting process using a laser as an energy source. Specifically, the present invention utilizes the high power density output of the laser pulsed light at the condensing point to instantaneously vaporize or melt the material at the condensing point of the laser light, thereby achieving material removal. The material heat removal zone extends to form a heat removal surface to effect the cutting separation of the material.

The cutting process of the present invention first illuminates and scans the laser light at or near the predetermined starting face of the workpiece to thermally remove material from the cutting face of the workpiece. After the cut surface of the workpiece is thermally removed, the material inside the workpiece is exposed to form a new surface. The laser light is then irradiated and scanned on the formed new surface to further remove the material, and finally the processed material on the entire predetermined cutting surface is thermally removed to complete the cutting. Specifically, first, the incident light is irradiated through the incident surface of the processed object and concentrated on the cutting start surface of the processed object to vaporize the processed material at the concentrated spot and/or the vicinity of the spot. And/or melted, thereby Forming an initial heat removal zone on the cutting starting surface, and continuously distributing the initial heat removal zone along the predetermined path on the cutting starting surface to form an initial heat removal line, and the plurality of heat removal lines are laterally stacked to form heat Remove the road. Thereafter, the laser light is irradiated to condense on or near the surface of the newly formed workpiece in the previous heat removal step, so that the processed material at the condensed spot and/or the vicinity of the condensed spot is vaporized and/or melted, thereby forming Subsequent heat removal zones, and subsequent heat removal zones are continuously distributed along a predetermined path to form a subsequent heat removal line, and a plurality of subsequent heat removal lines are laterally superposed to form a subsequent heat removal lane. The subsequent heat removal line, together with the previously formed initial heat removal line or subsequent heat removal line, at least partially forms a heat removal surface separating the workpieces. The concentrating on or near the cutting start surface of the workpiece (or the surface of the workpiece formed in the previous heat removal step) according to the present invention means that the spot position is at the cutting start surface (or before) On or in close proximity to the newly formed workpiece surface in the heat removal step, such that the formed heat removal zone comprises a cutting initiation surface (a newly formed workpiece surface in the previous heat removal step), ie, a spotlight spot The heat removal zone formed at the cutting initiation surface (the workpiece surface formed in the previous heat removal step) at or near the area is at least partially removed.

The present invention relates to an apparatus and method for cutting tempered glass such as Gorilla, Sodalime, and Dragontrail using dual-path laser pulsed light. The laser pulse illuminator is a nanosecond, picosecond and femtosecond laser with a wavelength of 266-1064 nm. The processing materials are ordinary glass, and Gorilla, Sodalime and Dragontrail. Transparent material such as tempered glass. During the cutting process, the optical scanning focusing system focuses the laser light on the lower surface of the transparent material (the surface of the workpiece formed in the previous heat removal step), and each layer of material is cut in a specific order at a specific interval to form a different glass thickness. With a suitable cutting width, the focus moves from bottom to top to achieve the purpose of cutting the material.

The present invention employs a nanosecond, picosecond or femtosecond laser with a short pulse of laser light. The laser pulsed light of the present invention is shorter than most chemical and physical reactions, such as mechanical and thermodynamic characterization time. The peak power density of the laser is extremely high. Due to the unique multiphoton absorption process between the ultrashort laser pulse light and the material, the processing precision can break through the bottleneck of the coherent limit, thus enabling nano processing and corresponding micro/nai Many ideas for electronics, micro/nai optics have become possible. The ultrashort laser pulsed light sequence can control the ionization process, selectively ionize atoms, control the rotation of the ground state in the molecule, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a view of a dual-optical laser pulsed light-cut tempered glass used in the present invention. At the beginning of the processing, the focus of the laser light is focused on the lower surface of the glass, and the laser light emitted by the laser pulse illuminator 1 controls the switching light through the electric shutter 2, and the software can control the sensing signal to control the opening and closing of the shutter 2. Thereby, the externally controlled laser switch of the laser pulse illuminator 1 is realized. After that, the laser beam is coaxially expanded by the beam expander 3 to improve the divergence angle of the beam propagation, thereby achieving the purpose of collimating the optical path; on the other hand, the size of the final focused spot of the laser light can be controlled, so that the desired The size of the spot is such that the purpose of laser stable cutting is achieved. After the beam expander 3 is expanded, the beam passes through a 45-degree half-reverse lens 4 and a 45-degree total reflection mirror 5, and the light routing level is changed to be vertically downward. The beam is focused by the 3D dynamic scanning focusing mirrors 6, 7 on the lower surface of the workpiece. The control system converts the cutting pattern into a digital signal, and then drives the reflecting lens in the 3D dynamic focusing galvanometer 6 to scan the processing pattern; the coaxial CCD 11 accurately positions the workpiece before the machining starts, and uses the calibration program to detect the positioning mark on the workpiece. The compensation value is calculated to achieve an exact match between the cutting pattern and the actual cutting path, and the processing progress and effect can be observed in real time during processing. After the start of processing, the blowing cooling and suction devices 8, 10 start to work, and the cutting residue is eliminated, and the blowing also serves as a cooling effect to improve the cutting quality; the 3D dynamic focusing mirror in the 3D dynamic scanning galvanometer 6 is processed at each time. One layer processing When finished, the focus is automatically raised, and the glass is cut through the bottom and the glass is cut through. After the processing is completed, the platform 9 automatically removes the glass from the processing position, facilitating material handling.

Figure 2 is a partial enlarged view of the laser cut of Figure 1. As shown, the laser light is cut separately in the two optical paths (only one optical path is shown in Fig. 2), and the laser light is transmitted through the upper surface of the glass to be concentrated near the lower surface or the lower surface of the glass. The high power density at the spotting point instantaneously vaporizes or melts the glass at and near the spot and exits or splatters from the lower surface of the glass to form a heat removal zone on the lower surface of the glass. The laser concentrating spot is horizontally moved relative to the glass, and the glass material along the moving path, the lower surface of the glass at or near the condensing point is continuously removed by heat to form a heat removing line, and the heat removing line is laterally superposed to form a heat removing path 32. . After the heat removal path of the predetermined path is formed on the lower surface of the glass, the laser condensing point is substantially shifted up by the thickness of the heat removal path so that the condensed spot falls on or near the newly formed glass surface in the previous heat removal process. The above steps are repeated to form a further heat removal passage above the heat removal passage 32. In this way, the glass material on the upper surface of the glass is thermally removed for the last time, so that the glass is completely cut through.

As shown in Figures 1-3, the laser processing apparatus of the present invention further includes an air blowing cooling device 8 arranged to blow air onto the upper surface of the glass 30 and an air suction collecting device 10 that draws air under the glass. The main function of the blowing cooling device 8 is to cool the upper surface of the glass, otherwise the last remaining thin glass on the upper surface of the glass will be broken due to heat accumulation, forming microcracks. The air blowing cooling device 8 can significantly suppress the generation of microcracks. Alternatively, the blower cooling device 8 is also used to blow away generated slag, debris, etc., when the uppermost layer of the laser cut glass is used. Since the present invention is processed from the bottom up, the vaporized or melted processed material or the like is automatically discharged from the glass 30 by gravity and thermal expansion of the air at the focus, and then collected by the suction collecting device 10.

Figure 3 shows a view similar to Figure 2 with the addition of a flexible material 40 under the glass. The flexible material 40 is sputtered on the surface when irradiated with laser light. The material of the flexible material 40 is spaced apart from the workpiece by a distance of, for example, 10 μm to 2 mm in the laser cutting region. The flexible material 40 can be paper, ink, aluminum, or the like. Preferably, the lower position of the laser cutting region flexible material is not fully supported by the platform. During the laser cutting process, part of the laser light is irradiated onto the flexible material 40 through the glass 30, and the flexible material 30 is thus sputtered, and the sputtered material partially adheres to the lower surface of the glass 30, so that the lower surface of the glass 30 The laser light absorption rate is increased so that the laser light can be cut at a lower laser power.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the invention is not limited thereto. In the preferred embodiment shown in the drawings, the laser light is incident from the upper surface of the glass and cut from the lower surface of the tempered glass, but the invention is not limited thereto. In an alternative embodiment, the laser light may also be incident from the side or lower surface of the tempered glass and may start from the upper surface, the side surface or the lower surface of the tempered glass as long as the incident surface and the cutting starting surface are different. The surface is fine.

In a preferred embodiment of the invention, the laser concentrating point is substantially shifted by the height of a thermal removal track each time a thermal removal lane is formed, although the invention is not limited thereto. In an alternative embodiment, the laser concentrating spot can be moved in different ways as long as the concentrating spot falls on or near the surface of the glass formed in the previous heat removal step, thereby allowing the newly formed heat removal line to be associated with the previous The heat removal lines partially overlap. The heat removal line of the present invention may also be of any shape as long as the heat removal line finally forms a heat removal surface separating the workpieces.

In a preferred embodiment of the invention, the workpiece is tempered glass, most preferably tempered glass such as Gorilla, Sodalime or Dragontrail. However, the invention is not limited thereto, and in alternative embodiments, the workpiece may be other types of glass or other materials through which laser light can pass.

In a preferred embodiment of the invention, the thickness of the tempered glass is less than or equal to 5mm, the depth of the tempered layer is less than or equal to 100μm. More preferably, the thickness of the tempered glass is less than or equal to 2 mm, and the depth of the tempered layer is less than or equal to 80 μm. However, the invention is not limited thereto, and the tempered glass of the present invention may have other thicknesses and tempered layer depths.

In a preferred embodiment of the invention, the laser source emits a laser pulse having a width of 50 ps to 15 ns, a peak laser power of 0.1 to 1 MW, and a heat removal line having a width of 10 to 60 μm. However, the invention is not limited thereto, and the laser light source of the present invention may be a nanosecond laser, a picosecond laser or a femtosecond laser, and the heat removal line may have other widths.

In a preferred embodiment of the invention, the laser beam is split into two beams using a 45 degree half mirror to simultaneously cut. However, the present invention is not limited thereto, and the present invention may use a laser beam for cutting, or may divide the laser light into 3, 4 or more beams for cutting.

In a preferred embodiment of the invention, the upper surface of the glass is cooled by an air-cooling device arranged to blow the upper surface of the glass. However, the invention is not limited thereto, and other cooling means may be employed to cool the upper surface of the glass.

In a preferred embodiment of the present invention, a heat removal line is formed, and a plurality of heat removal lines are laterally superposed to form a heat removal path for increasing the cutting width, and then the laser condensing point is moved up by a predetermined distance, thereby The height forms a heat removal path that only forms a specific width. However, the present invention is not limited thereto, and heat removal paths of different widths may be formed at different focus heights, so that the shape of the cut cross section can be set. For a glass having a thickness of 0.5 to 2 mm, the cutting width is preferably from 100 to 400 μm. In a preferred embodiment, each heat removal lane is formed by laterally superimposing a plurality of heat removal lines, although the invention is not limited thereto, and in an alternative embodiment, at least some of the heat removal lanes are comprised of one heat removal line. In still other alternative embodiments, all of the heat removal passes are comprised of a single heat removal line.

The above-mentioned embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

1‧‧‧Laser pulser

2‧‧‧Shingles

3‧‧‧beam expander

4‧‧‧45 degree semi-transparent mirror

5‧‧.45 degree total reflection mirror

6‧‧‧3D dynamic scanning galvanometer

7‧‧‧ Focusing mirror

8‧‧‧Blowing air cooling device

9‧‧‧ platform

10‧‧‧ suction device

11‧‧‧ coaxial CCD

20‧‧‧Laser beam

30‧‧‧ glass

32‧‧‧Cut Road

40‧‧‧Flexible materials

50‧‧‧residue

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of tempered glass cutting using the laser processing apparatus of the present invention.

Figure 2 is a partial enlarged view of a laser cut.

Figure 3 is a schematic view similar to Figure 2 with a flexible material added under the glass.

1‧‧‧Laser pulser

2‧‧‧Shingles

3‧‧‧beam expander

4‧‧‧45 degree semi-transparent mirror

5‧‧.45 degree total reflection mirror

6‧‧‧3D dynamic scanning galvanometer

7‧‧‧ Focusing mirror

8‧‧‧Blowing air cooling device

9‧‧‧ platform

10‧‧‧ suction device

11‧‧‧ coaxial CCD

Claims (26)

A laser processing method comprising the steps of: illuminating a laser beam through an incident surface of a workpiece, and concentrating light on a cutting start surface of the workpiece to make a condensing point and/or the The workpiece in the vicinity of the concentrating spot is vaporized and/or melted to form an initial heat removal zone on the cutting initiation surface, and the initial heat removal zone is along a predetermined path along the cutting initiation surface Continuously distributed to form an initial heat removal line; illuminating the laser light to condense on or near the surface of the workpiece formed in the previous heat removal step, such that the collection point and/or the vicinity of the collection point The workpiece is vaporized and/or melted to form a subsequent heat removal zone, and the subsequent heat removal zone is continuously distributed along the predetermined path to form a subsequent heat removal line, wherein the initial heat removal line and a strip Or a plurality of the subsequent heat removal lines together form a heat removal face separating the workpiece such that a workpiece material is removed by heat throughout the heat removal face. The laser processing method of claim 1, wherein the step of forming the initial heat removal line comprises laterally superimposing a plurality of the initial heat removal lines to form an initial heat removal path to form the subsequent heat removal. The step of the line includes laterally superimposing a plurality of the subsequent heat removal lines to form a subsequent heat removal track. The laser processing method of claim 2, wherein the incident surface is an upper surface of the workpiece, and the cutting starting surface is a lower surface of the workpiece, the method further comprising: forming the After the initial heat removal track or the subsequent heat removal track, the spot is moved up by a predetermined distance relative to the workpiece to The subsequent heat removal path is formed at the height of the focused spot that is moved up. The laser processing method of claim 1, wherein the workpiece is glass. The laser processing method of claim 1, wherein the workpiece is tempered glass. The laser processing method according to claim 1, wherein the processed material is a diamond glass, a soda lime glass or a tall glass. The laser processing method of claim 5, wherein a tempered layer depth of the tempered glass is less than or equal to 100 μm, and a thickness of the tempered glass is less than or equal to 5 mm. The laser processing method according to claim 1, wherein the laser light is generated by a nanosecond laser, a picosecond laser or a femtosecond laser, and the peak power of the laser light is At 0.1-1 MW, a width of the initial heat removal line or the subsequent heat removal line is 10-60 μm. The laser processing method of claim 1, further comprising: dividing the laser light into two or more beams before the laser light is incident on the workpiece, each of the beam of laser light being used for each Separate cutting. The laser processing method according to claim 1, further comprising: disposed under the workpiece, capable of sputtering when irradiating the laser light A material in which the material and the workpiece are separated by a distance. The laser processing method of claim 10, wherein the material comprises paper, ink, aluminum. The laser processing method of claim 1, further comprising the step of cooling the incident surface. The laser processing method of claim 12, further comprising the step of performing the cooling using an air blowing device. The laser processing method of claim 1, further comprising sucking the gasified and melted workpiece with a getter device. A laser processing apparatus for performing a laser cutting of a processed object, comprising: a laser light source adapted to emit a laser pulsed light; and a light collecting means adapted to emit the laser light source The laser pulsed light is condensed on the surface or inside of the workpiece such that a power density at the at least one condensing point enables the workpiece to be vaporized and/or melted to form a heat removal zone; And moving the concentrating spot relative to the workpiece, the moving device is configured to: pass the laser pulse light through an incident surface of the workpiece, and condense to form the concentrating spot on the workpiece Forming or near the cutting start surface, vaporizing and/or melting the workpiece at the concentrating point and/or the vicinity of the concentrating point to form an initial heat removal on the cutting starting surface And causing the initial heat removal zone to be continuously distributed along the predetermined path along the cutting starting surface to form an initial heat removal line; such that the concentrating spot is concentrated on the surface of the workpiece formed in the previous heat removal Upper or lower, such that the workpiece at the concentrating point and/or the vicinity of the concentrating point is vaporized and/or melted to form a subsequent heat removal zone, and the subsequent heat removal zone is along a predetermined path Continuously distributed to form a subsequent heat removal line, wherein the initial heat removal line and one or more of the subsequent heat removal lines together form a heat removal surface separating the workpiece such that the entire heat removal surface A workpiece material is removed by heat. The laser processing apparatus of claim 15, wherein the moving device further comprises: configured to laterally superimpose the plurality of the initial heat removal lines to form an initial heat removal track, and to remove the plurality of subsequent heat removals. The lines are laterally superimposed to form a subsequent heat removal track. The laser processing apparatus of claim 16, wherein the incident surface is an upper surface of the workpiece, and the cutting starting surface is a lower surface of the workpiece, wherein the moving device further comprises After forming the initial thermal removal lane or the subsequent thermal removal lane, the concentrating spot is positioned up by a predetermined distance to form the subsequent thermal removal trajectory at the height of the concentrating point that moves up. The laser processing apparatus of claim 15, wherein the workpiece is tempered glass. The laser processing apparatus of claim 18, wherein the The processed material is a diamond glass, a soda lime glass or a tall glass. The laser processing apparatus of claim 15, wherein the laser source is a nanosecond laser, a picosecond laser or a femtosecond laser, and one of the peaks of the laser pulse light The power is between 0.1 and 1 MW. The laser processing apparatus of claim 15, further comprising: a beam splitting device adapted to split the laser pulse light incident before the workpiece into two or more laser beams. The laser processing apparatus of claim 15, further comprising: a material disposed under the workpiece for sputtering when irradiating the laser pulse light, and one of the laser pulse light At the illumination, the material is spaced a distance from the workpiece. The laser processing apparatus of claim 22, wherein the material comprises paper, ink, aluminum. A laser processing apparatus according to claim 15 further comprising a cooling device for cooling the incident surface of the workpiece. The laser processing apparatus of claim 24, wherein the cooling device is a blowing device. The laser processing apparatus of claim 15, further comprising a getter device for sucking away the processed product that is vaporized and melted.