Method for quickly and precisely forming through hole by using infrared laser

Abstract

The invention discloses a method for quickly and precisely forming a through hole by using infrared laser. A single modulated Bessel beam is sequentially irradiated to a workpiece to be processed in a scanning manner by using a mirror structure combined with at least one driving part, so that the workpiece is quickly and precisely micromachined into various shapes and sizes or shapes to form a laser scanning processing pattern for changing the character of the workpiece to be processed, and then wet etching is performed. Therefore, compared with the prior art, the laser processing time can be obviously shortened, the processed workpiece can be quickly subjected to laser processing, the etching time can be shortened, and the production efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to a method for forming a through hole quickly and precisely using an infrared laser, and more specifically, to the following method for forming a through hole quickly and precisely using an infrared laser, namely, by scanning a mirror structure combined with at least one driving unit, a modulated Bessel light beam is sequentially irradiated to a workpiece to quickly and precisely micro-process it into various sizes or shapes to form a laser scanning processing pattern that changes the properties of the workpiece, and then wet etching is performed. Therefore, compared with the past, not only can the laser processing time be significantly shortened, the workpiece can be laser processed quickly, but the etching time can also be shortened to improve production efficiency. Background Art

[0002] Lasers are widely used for cutting workpieces (processing objects) or forming through holes. This type of laser processing uses optical devices such as lenses to form a laser beam in the shape required for the processing operation and irradiates the formed laser beam on the workpiece.

[0003] In particular, laser beams can be effectively used to cut or form through holes in brittle materials that are difficult to process, such as transparent glass substrates. However, when processing glass substrates, the workpiece may be cracked and split due to the laser.

[0004] Furthermore, when the glass substrate, which is a brittle material, has its internal properties changed due to external stains or foreign matter, there is a possibility that the inner wall of the through-hole may become non-uniform.

[0005] Furthermore, when using laser to form fine through holes on a glass substrate, there are problems such as high difficulty in precision machining and long work time, which results in reduced production efficiency.

[0006] A related prior art document is Korean Patent Publication No. 10-2016-0063264 (published on June 3, 2016). Summary of the invention

[0007] Technical issues

[0008] The object of the present invention is to provide a method for forming through holes quickly and precisely using infrared lasers, by scanning a mirror structure combined with at least one driving unit to sequentially irradiate a modulated Bessel light beam to a workpiece to quickly and precisely micro-process it into various sizes or shapes to form a laser scanning processing pattern that changes the properties of the workpiece, and then etching is performed. Therefore, compared with the past, not only can the laser processing time be significantly shortened, the workpiece can be laser processed quickly, the etching time can also be shortened, and production efficiency can be improved.

[0009] Technical Solution

[0010] In order to achieve the above-mentioned purpose, the method for forming a through hole quickly and precisely using an infrared laser according to an embodiment of the present invention comprises: step (a), aiming an infrared laser device at the upper part of a workpiece; step (b), modulating the laser beam emitted from the infrared laser device into a Bessel beam; step (c), performing laser processing on each through hole forming area of ​​the workpiece by scanning and sequentially irradiating the modulated Bessel beam to form a laser scanning processing pattern that locally changes the properties of the workpiece; and step (d), etching the workpiece on which the laser scanning processing pattern is formed to form through holes in each of the through hole forming areas.

[0011] The laser beam uses ultrashort laser light having a wavelength of 900 nm to 1200 nm and a pulse width of 50 femtoseconds to 50 picoseconds.

[0012] In the above-mentioned laser scanning processing pattern, the individual dots formed by the above-mentioned laser processing have an arrangement structure separated at regular or irregular intervals to form a shape corresponding to the above-mentioned through hole when viewed from a plane.

[0013] Viewed from a planar perspective, in the above-mentioned laser scanning processing pattern, the individual points formed by the above-mentioned laser processing are separated by regular or irregular intervals of less than 20 μm and have an arrangement structure corresponding to the above-mentioned through holes in one or more shapes selected from polygons including triangles, quadrilaterals, pentagons, hexagons, octagons and stars, circles and ellipses.

[0014] Viewed from a planar perspective, the laser scanning processing pattern includes: a first laser scanning processing pattern, which is arranged at regular or irregular intervals to have a shape corresponding to the through hole; and at least one second laser scanning processing pattern, which is arranged on the inner side of the first laser scanning processing pattern.

[0015] The second laser scanning processed pattern has an arrangement structure having the same shape or a different shape from that of the first laser scanning processed pattern.

[0016] When viewed from a plane, the laser scanning processing pattern has an arrangement structure of straight lines or curves in which a plurality of points are connected to each other, so as to have a shape corresponding to the through hole.

[0017] Preferably, the workpiece is a flat glass substrate.

[0018] In the step (c), the scanning laser processing is performed by scanning using a mirror structure coupled with at least one driving unit, so that the scanning laser processing is performed within a stabilization time of 10 ms or less.

[0019] In the above step (d), the through holes located in the through hole forming regions are formed on the same plane, or at least a part of them are formed on different planes.

[0020] In the step (d), the etching is performed by wet etching using at least one etchant selected from a fluorinated etchant and a non-fluorinated etchant.

[0021] The above-mentioned step (d) includes: step (d-1), infiltrating the etchant into the laser scanning processing pattern of the workpiece whose properties have been locally changed by the above-mentioned laser processing, so that a part of the exposed surface of the above-mentioned workpiece is removed along the thickness direction, thereby forming a plurality of etching grooves; and step (d-2), as the etchant penetrates along the above-mentioned plurality of etching grooves toward the thickness center of the workpiece, the stacked part of the workpiece whose properties have been changed in the space between the above-mentioned laser scanning processing patterns naturally falls off or corrodes, thereby forming a through hole.

[0022] The inner wall of the through hole has a taper angle ranging from an acute angle to an obtuse angle relative to a horizontal plane of the workpiece.

[0023] Effects of the Invention

[0024] The rapid and precise through-hole forming method using infrared laser of the present invention utilizes a mirror structure combined with at least one driving part to scan and sequentially irradiate a modulated Bessel light beam to the workpiece to rapidly and precisely micro-process it into various sizes or shapes.

[0025] As described above, the method for forming a fast and precise through-hole using an infrared laser of the present invention adopts a scanning method for laser processing by adjusting the reflection angle of a mirror structure combined with at least one driving part. Therefore, unlike the general through-hole forming method of only moving the workbench, it can not only shorten the stabilization time during laser processing to less than about 10ms, but also will not be affected by the size of the workpiece being processed by the laser.

[0026] Therefore, compared with a general through-hole forming method, the rapid and precise through-hole forming method using infrared laser of the present invention can rapidly perform laser processing at a speed more than 100 times faster, thereby greatly improving production efficiency.

[0027] In addition, the rapid and precise through-hole forming method using infrared laser of the present invention can quickly and precisely control the processing position of the workpiece, can implement wet etching in a state where the internal properties of the workpiece are partially changed so that it has the same or similar size or shape as the through-hole, can significantly shorten the etching time, and thus reduce the cost of etching agent consumption, can improve the uniformity of the quality of multiple through-holes formed on the entire workpiece while improving production efficiency. Therefore, since the stacked body part of the workpiece with changed properties located between the multiple etching grooves in the present invention will be removed due to natural falling off or corrosion, compared with the general through-hole forming method, a through-hole of a desired size can be formed in a very short time.

[0028] In addition, the method for forming a fast and precise through-hole using an infrared laser of the present invention performs wet etching in a state where a laser scanning processing pattern is formed by sequentially irradiating each through-hole forming area of ​​the workpiece in a scanning manner with a Bessel beam. Therefore, in the present invention, even if a part of the laser scanning processing patterns located in each through-hole forming area is defective due to stains or foreign matter outside the workpiece, causing uneven changes in the properties of part of the workpiece, other laser scanning processing patterns are arranged around it, so that it can be not greatly affected during wet etching, thereby ensuring the product quality of the through-hole.

[0029] Finally, the rapid and precise through-hole forming method using infrared laser of the present invention can ensure that the diameter of the surface portion of the through-hole and the diameter of the center portion of the through-hole remain uniform during wet etching.

[0030] Furthermore, the rapid and precise through-hole forming method using infrared laser of the present invention implements wet etching by utilizing a laser scanning processing pattern having an arrangement structure separated by regular or irregular intervals, so that the through-hole having a shape that is actually the same as or similar to the laser scanning processing pattern can also have a variety of shapes, thereby achieving diversification. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figures 1 to 4 The figure is a cross-sectional view showing a process of forming a through hole using a conventional infrared laser.

[0032] Figure 5 A schematic diagram for explaining a conventional laser Bessel beam optical modulation device.

[0033] Figure 6 To illustrate the use Figure 5 Top view of the laser Bessel beam optical modulation device to form the laser processing point.

[0034] Figure 7The figure is a process flow chart showing a method for forming a rapid and precise through hole using an infrared laser according to an embodiment of the present invention.

[0035] Figure 8 FIG. 1 is a schematic diagram showing an infrared laser device according to an embodiment of the present invention.

[0036] Fig. 9 To illustrate the use Figure 8 A top view of a laser scanning processing pattern formed by an infrared laser device.

[0037] Figures 10 to 12 The figure is a cross-sectional view showing a process of forming a rapid and precise through-hole using an infrared laser according to an embodiment of the present invention.

[0038] Fig.13 The following are top views showing various application examples of the laser scanning processing pattern according to the embodiment of the present invention.

[0039] Fig.14 The present invention is a top view showing various application examples of laser scanning processing patterns according to a modified example of the present invention.

[0040] Fig.15 The following is a plan view showing various application examples of the laser scanning processing pattern according to another modified example of the present invention.

[0041] Fig.16 The figure is a process picture showing the formation process of the through hole produced according to Comparative Example 1.

[0042] Fig.17 The figure is a process picture showing the formation process of the through hole manufactured according to Example 1. DETAILED DESCRIPTION

[0043] The advantages, features and methods of achieving the same will become clear with reference to the embodiments described in detail below in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in many other forms. This embodiment is only provided to make the disclosure of the present invention more complete and to inform the ordinary technicians in the technical field to which the present invention belongs of the scope of the invention. The present invention is only defined by the scope of the invention. Throughout the specification, the same figure numerals represent the same structural elements.

[0044] Hereinafter, a method for forming a rapid and precise through-hole using an infrared laser according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0045] Figures 1 to 4 1 is a cross-sectional view showing a process of forming a through hole using a conventional ultra-short infrared laser. Figure 5 is a schematic diagram for explaining a conventional laser Bessel beam optical modulation device, Figure 6For use Figure 5 Top view of the laser Bessel beam optical modulation device to form the laser processing point.

[0046] like Figure 1 , Figure 5 and Figure 6 As shown, after a conventional laser Bessel beam optical modulation device is aligned with the upper portion of the workpiece 110 , the Bessel beam BB emitted by the laser Bessel beam optical modulation device is irradiated onto the workpiece 110 to form a laser processing point 125 .

[0047] The laser beam LB emitted from the conventional laser Bessel beam optical modulation device is modulated into a Bessel beam BB when passing through the objective lens-based optical device 140, and the modulated Bessel beam BB is irradiated onto the workpiece 110 and forms a laser processing point 125. The optical device 140 may be a non-diffraction device for modulating the laser beam LB into the Bessel beam BB, but is not limited thereto. Therefore, when observed from the direction of beam travel, the laser beam LB may be modulated into a ring-shaped Bessel beam BB when passing through the objective lens-based optical device 140.

[0048] Then, if Figures 2 to 4 As shown, the workpiece 110 having the laser processing point 125 formed thereon is etched to form the through hole TH.

[0049] In this step, etching may be performed by wet etching using a fluorinated etchant, a non-fluorinated etchant, or the like, but this is merely exemplary, and any etchant that can etch a glass substrate may be used without limitation.

[0050] In this case, Figure 2 , the initial etching process is shown in FIG. 1 , and it can be confirmed that as the etchant penetrates into the portion whose properties are changed by the laser processing point 125 , etching gradually proceeds, thereby forming an etching groove E having a first width W1 .

[0051] Figure 3 The intermediate etching process is shown, and it can be confirmed that as time goes by, the etchant further penetrates along the etching groove E, and the size of the etching groove E expands to a second width W2 that is wider than the first width W1.

[0052] also, Figure 4 The later etching process is shown. As time goes by, due to the reaction with the etchant, the workpiece 110 will gradually move along the etching groove ( Figure 3 E) is removed, the diameter of the etching groove is expanded, and finally the upper and lower etching grooves are connected to form a through hole TH.

[0053] In the above-mentioned general through-hole forming method, in order to form a micron-sized fine through-hole TH on a workpiece 110 made of a transparent and brittle material, an infrared laser is usually used to irradiate a modulated Bessel light beam BB onto the workpiece 110 to form a laser processing point 125 in each through-hole forming area to change the properties, and then the wet etching time is adjusted to form the desired final size.

[0054] However, the general through-hole forming method adopts a step-and-repeat processing method by moving a workbench for placing the workpiece 110 and irradiating the Bessel beam BB in each through-hole forming area. When the workbench is moved to the through-hole forming area, the total time including the acceleration and deceleration time and the stabilization time is usually 100ms to 1000ms, which takes a considerable time. Therefore, the larger the size of the workpiece 110 used for laser processing, the larger the size of the workbench needs to be, and the longer the acceleration and deceleration and stabilization time. Ultimately, when the size of the workpiece 110 increases, the overall laser processing time will increase significantly, resulting in a decrease in production efficiency. In addition, as the number of through holes TH increases, the acceleration and deceleration and stabilization time also increase, thereby greatly increasing the processing time and resulting in a decrease in production efficiency.

[0055] Furthermore, in a general through-hole forming method, since the Bessel beam BB irradiates each through-hole forming region of the workpiece 110, the Bessel beam BB irradiated along the thickness direction of the workpiece 110 performs intensive laser processing on only one processing position. Therefore, if there are surface defects such as foreign matter or stains on the workpiece 110 at the processing position, it is likely that the internal properties of the workpiece 110 made of brittle material cannot be uniformly changed. This will eventually lead to poor through-holes TH during wet etching, which will not only affect the uniformity of the size or shape of the multiple through-holes TH located in each through-hole forming region, but also make the size between the surface diameter d1 of the through-hole TH and the center diameter d2 of the through-hole TH during wet etching uneven, thereby becoming a factor that reduces the taper angle θ and leads to a decrease in product quality.

[0056] Therefore, in a general through-hole forming method, the quality of the multiple final through-holes TH formed in each through-hole forming area of ​​the workpiece 110 is inevitably greatly affected by the etching performance, so there are limitations in ensuring uniform quality of the through-holes TH. Depending on the final size of the through-hole TH, more than several hours of etching time is required, and mass production is restricted.

[0057] Furthermore, the general through-hole forming method is sensitively affected by the surface conditions of the workpiece 110 , such as whether foreign matter and stains are removed from the surface, and therefore has limitations in ensuring the uniformity of the quality of the plurality of through-holes TH arranged on the entire workpiece 110 .

[0058] Furthermore, in a general through-hole forming method, a Bessel beam BB is irradiated on each through-hole forming area of ​​the workpiece 110 to form a laser processing point 125, and the through-hole TH is formed by gradually expanding the hole size of the laser processing point 125 by wet etching using an etchant. Therefore, there are limitations in the shape diversification of the through-hole TH.

[0059] In order to solve the above problems, the method for forming through holes quickly and precisely using infrared laser in an embodiment of the present invention utilizes a mirror structure combined with at least one driving unit to scan and irradiate a modulated Bessel light beam to the workpiece in sequence, thereby quickly and precisely micro-machining the workpiece into various sizes or shapes.

[0060] As described above, the method for forming a fast and precise through-hole using an infrared laser in an embodiment of the present invention adopts a scanning method for laser processing by moving a mirror structure combined with at least one driving unit. Therefore, unlike a general through-hole forming method in which only a workbench is moved, not only can the stabilization time during laser processing be shortened to less than about 10ms, more preferably, it can be shortened to less than 1ms, and it will not be affected by the size of the workpiece being processed by the laser.

[0061] Therefore, compared with a general through-hole forming method, the rapid and precise through-hole forming method using infrared laser according to an embodiment of the present invention can rapidly perform laser processing at a speed more than 100 times faster, thereby greatly improving production efficiency.

[0062] In addition, the rapid and precise through-hole forming method using infrared laser in the embodiment of the present invention can quickly and precisely control the processing position of the workpiece, and can perform wet etching while partially changing the internal properties of the workpiece so that it has the same or similar size or shape as the through-hole. This can significantly shorten the etching time and thereby reduce the etching agent consumption cost. Therefore, it is possible to improve the uniformity of the quality of multiple through-holes formed on the entire workpiece while improving production efficiency.

[0063] Hereinafter, a method for forming a rapid and precise through hole using an infrared laser according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0064] Figure 7 To illustrate a process flow chart of a method for forming a rapid and precise through hole using an infrared laser according to an embodiment of the present invention, Figure 8 Schematic diagram of an infrared laser device according to an embodiment of the present invention. Fig. 9 To illustrate the use Figure 8 A top view of a laser scanning processing pattern formed by an infrared laser device. Figures 10 to 12The figure is a cross-sectional view showing a process of forming a rapid and precise through-hole using an infrared laser according to an embodiment of the present invention.

[0065] like Figure 7 As shown, the method for forming a fast and precise through hole using infrared laser according to an embodiment of the present invention includes an infrared laser device alignment step S210, a laser beam modulation step S220, a laser scanning processing pattern formation step S230, and a through hole formation step S240 based on wet etching.

[0066] Aiming infrared laser device

[0067] like Figure 7 and Figure 8 As shown, in the infrared laser device alignment step S210 , the infrared laser device 200 is aligned with the upper portion of the workpiece 210 .

[0068] The workpiece 210 may have a flat plate shape, but is not limited thereto. In addition, the workpiece 210 may be a transparent glass substrate of a brittle material that is difficult to process. However, the workpiece 210 is not limited to a transparent glass substrate, and may include a variety of materials such as an opaque substrate, a metal material, and a semiconductor wafer.

[0069] Modulating laser beams

[0070] like Figure 7 and Figure 8 As shown, in the laser beam modulation step S220, the laser beam LB emitted by the infrared laser device 200 is modulated into a Bessel beam BB.

[0071] The infrared laser device 200 may include a laser unit 220 , a first optical unit 240 and a second optical unit 260 .

[0072] The laser unit 220 emits a laser beam LB for processing the workpiece 210. Such a laser unit 220 can generate a laser with pulses and emit it in the form of a beam. In this case, the emitted laser beam LB can have a pulse of wavelength, energy and duration suitable for processing the workpiece 210, that is, an ultra-short pulse or a burst pulse. More specifically, the laser beam LB can use an ultra-short laser with a wavelength of 900nm to 1200nm and a pulse width of 50 femtoseconds to 50 picoseconds. In addition, when observed from the emission direction, the laser beam LB can have a circular shape or a Gaussian beam shape.

[0073] The first optical unit 240 is disposed on the path of the laser beam LB and modulates the incident laser beam LB into a Bessel beam BB. To this end, the first optical unit 240 may include a first optical device 242 for modulating the laser beam LB into a Bessel beam BB and a second optical device 244 disposed behind the first optical device 242.

[0074] The first optical device 242 may be a non-diffractive device for modulating the laser beam LB into the Bessel beam BB, but is not limited thereto. Such a first optical device 242 may also be a diffractive device for modulating the laser beam LB into a beam that can form a filament through nonlinear absorption.

[0075] As an example, the first optical device 242 may be a conical prism or an axicon lens for modulating the laser beam LB into the Bessel beam BB. Therefore, when viewed from the beam traveling direction, the laser beam LB may be modulated into a ring-shaped Bessel beam BB when passing through the first optical device 242.

[0076] The first optical device 242 is not limited to a conical prism or an axicon lens, but may be a variety of optical devices that can modulate the laser beam LB into a Bessel beam BB. For example, a diffractive optical element or other diffractive optical element, a spatial light modulator or other optical devices may be used as the first optical device 242.

[0077] In addition, a second optical device 244 may be installed behind the first optical device 242 to limit the expansion of the irradiation area of ​​the Bessel beam to be suitable for processing the workpiece 210 after the laser beam LB is modulated into the Bessel beam BB by the first optical device 242 .

[0078] That is, the second optical device 244 may be an optical device for parallelizing the optical axis of the Bessel light beam BB modulated by the first optical device 242. As an example, the second optical device 244 may be a collimating lens or a collimating lens. The optical axis of the Bessel light beam BB passing through the second optical device 244 may be parallelized and then incident on the second optical unit 260.

[0079] By appropriately selecting or adjusting the optical properties, arrangement intervals, etc. of the first optical device 242 and the second optical device 244 , the light beam is emitted into the second optical unit 260 through the second optical device 244 .

[0080] The second optical unit 260 is used to reflect the Bessel light beam BB modulated by the first optical unit 240 onto the workpiece 210 , and may include a mirror structure 262 and a focusing lens 264 .

[0081] The mirror structure 262 is combined with at least one driving unit. Thus, the reflection angle of the mirror structure 262 can be adjusted in real time by at least one driving unit, so that the Bessel beam BB can be quickly reflected in the direction of the workpiece 210. The mirror structure 262 can be a fine steering mirror (FSM) combined with one driving unit or a scanner combined with two or more driving units.

[0082] The mirror structure 262 can move the path of the Bessel light beam BB modulated by the first optical unit 240. That is, the mirror structure 262 can continuously change the optical axis direction of the Bessel light beam BB modulated by the first optical unit 240 within a predetermined angle range, thereby, the Bessel light beam BB modulated by the first optical unit 240 can be sequentially irradiated on each through hole forming area on the workpiece 210 in a scanning manner.

[0083] The mirror structure 262 may include at least one mirror with an adjustable angle. Thus, the Bessel light beam BB incident on the mirror structure 262 is reflected by the mirror, and the reflection angle of the reflected Bessel light beam BB can be adjusted. For example, the mirror structure 262 may include a plurality of mirrors rotatable along a rotation axis arranged in at least two axial directions, and may be composed of a galvano mirror. The mirror structure 262 as described above is not limited to a galvano mirror.

[0084] The Bessel light beam BB whose path is changed by the mirror structure 262 may be focused on the workpiece 210 by the focusing lens 264 .

[0085] The focusing lens 264 may be disposed behind the scanner 262 and above the workpiece 210 . Thus, the Bessel beam BB emitted from the mirror structure 262 may be irradiated onto each through-hole forming region of the workpiece 210 in a scanning manner through the focusing lens 264 .

[0086] Forming laser scanning processing pattern

[0087] like Figures 7 to 10 As shown, in the laser scanning processing pattern forming step S230, laser processing is performed by scanning each through hole forming area of ​​the workpiece 210 and sequentially irradiating the modulated Bessel beam BB to form a laser scanning processing pattern 225 that locally changes the properties of the workpiece 210.

[0088] Such laser scanning processing patterns 225 are arranged in respective through-hole forming regions.

[0089] In this case, the present invention uses a mirror structure 262 combined with at least one driving unit to scan and sequentially irradiate the workpiece 210 with a modulated Bessel beam to perform laser processing.

[0090] Therefore, in the present invention, a Bessel light beam BB modulated by adjusting the reflection angle of the mirror structure 262 combined with at least one driving unit is irradiated in a scanning manner, so that the laser scanning processing pattern 225 can be formed quickly and accurately.

[0091] As described above, the present invention adopts a scanning method for laser processing by adjusting the reflection angle of the mirror structure 262 combined with at least one driving unit. This means that the acceleration, deceleration and stabilization time when moving to the through hole TH formation area is less than 10ms, which is significantly shorter than the time of only moving the worktable to the through hole formation area. Therefore, it will not be affected by the size of the workpiece 210 to be processed by laser processing.

[0092] Therefore, compared with a general through-hole forming method, the rapid and precise through-hole forming method using infrared laser according to an embodiment of the present invention can rapidly perform laser processing at a speed more than 100 times faster, thereby greatly improving production efficiency.

[0093] Preferably, in the laser scanning processing pattern 225, the individual dots formed by laser processing are spaced at regular or irregular intervals of 20 μm or less in plane view, thereby having a shape corresponding to a through hole, but the invention is not limited thereto. That is, in the laser scanning processing pattern 225, the individual dots formed by laser processing can also be spaced at irregular intervals of 20 μm or less in plane view, thereby having a shape corresponding to a through hole.

[0094] Among them, Fig. 9 As shown, viewed from a plane, in the laser scanning processing pattern 225, the modulated Bessel light beam can be used to irradiate the through hole forming area of ​​each workpiece 210 in a scanning manner using a mirror structure combined with at least one driving unit, so that a plurality of laser processing points separated by regular intervals form a circular arrangement structure.

[0095] As described above, when the laser scanning processing patterns 225 are spaced at regular intervals or irregular intervals to form a circular arrangement structure, the area of ​​the workpiece 210 where the properties are changed can be increased by irradiating the Bessel beam BB on each through hole forming area of ​​the workpiece 210 respectively.

[0096] Therefore, the area of ​​the workpiece 210 where the properties are changed increases proportionally with the number of points in the laser scanning processing pattern 225, thereby increasing the number of points in the laser scanning processing pattern 225 where fine holes are formed on the workpiece 210 by laser processing during wet etching, thereby increasing the area that is easy for the etchant to penetrate, thereby significantly reducing the etching time.

[0097] on the other hand, Fig.13 The following are top views showing various application examples of the laser scanning processing pattern according to the embodiment of the present invention.

[0098] like Fig.13 As shown, the modulated Bessel beam is irradiated on the workpiece in a scanning manner and arranged at regular or irregular intervals so that the laser scanning processing pattern 225 has the same or similar shape as the shape of the through hole finally formed after wet etching.

[0099] Therefore, since the shape of the through hole is determined by the arrangement shape of the laser scanning processing pattern 225, when the arrangement shape of the laser scanning processing pattern 225 is changed in various ways, various through holes can be formed in corresponding shapes.

[0100] That is, Fig.13 As shown in part (a), in the laser scanning processing pattern 225, the plurality of laser processing points may have a circular arrangement structure when viewed from a plane.

[0101] And, if Fig.13 As shown in parts (b), (c) and (d), in the laser scanning processing pattern 225, the plurality of laser processing points may respectively have a star-shaped, quadrilateral and triangular arrangement structure when viewed from a plane.

[0102] However, the laser scanning processed pattern 225 is not limited to the above-mentioned arrangement structure. That is, the laser scanning processed pattern 225 can be applied to an arrangement structure in which a plurality of laser processing points are arranged in a polygonal shape such as a pentagon, hexagon, octagon, or an elliptical shape.

[0103] Fig.14 The present invention is a top view showing various application examples of laser scanning processing patterns according to a modified example of the present invention.

[0104] like Fig.14 As shown in parts (a) to (d), from a planar perspective, the laser scanning processing pattern 225 may include: first laser scanning processing patterns 225a, which are arranged at regular or irregular intervals to have a shape corresponding to the above-mentioned through holes; and at least one second laser scanning processing pattern 225b, which is arranged on the inner side of the first laser scanning processing pattern 225a.

[0105] In this case, Fig.14 Part (a) shows, as an example, a first laser scanning pattern 225a and two second laser scanning patterns 225b arranged in an annual ring shape inside the first laser scanning pattern 225a.

[0106] As described above, the second laser scanning processed pattern 225b may have an arrangement structure having the same shape as the first laser scanning processed pattern 225a.

[0107] And, in Fig.14 Part (b) shows, as an example, a first laser scanning pattern 225a and a second laser scanning pattern 225b having a spiral structure arranged inside the first laser scanning pattern 225a.

[0108] And, in Fig.14 Part (c) shows, as an example, a first laser scanning pattern 225a and a second laser scanning pattern 225b having a cross structure arranged inside the first laser scanning pattern 225a.

[0109] And, in Fig.14 Part (d) shows, as an example, a first laser scanning pattern 225a and a second laser scanning pattern 225b arranged radially and intersecting inside the first laser scanning pattern 225a.

[0110] like Fig.14 As shown in parts (b) to (d) of FIG. 1 , the second laser scanning processed pattern 225 b may also have an arrangement structure with a shape different from that of the first laser scanning processed pattern 225 a .

[0111] As reference Fig.14 As described in parts (a) to (d) of the present invention, when the laser scanning processing pattern 225 is designed to have a first laser scanning processing pattern 225a and at least one second laser scanning processing pattern 225b, the number of points of the laser scanning processing pattern 225 can be increased, thereby further increasing the number of regions where the properties of the workpiece 210 are changed to increase the channels that are easier to penetrate the etchant, thereby further shortening the etching time. Ultimately, not only can the etching time be significantly shortened, but also the consumption of the etchant can be significantly reduced, thereby maximizing the production efficiency.

[0112] and, Fig.15 The following is a plan view showing various application examples of the laser scanning processing pattern according to another modified example of the present invention.

[0113] like Fig.15As shown in parts (a) to (c) of FIG. 1 , from a plane perspective, the laser scanning processing pattern 225 may have an arrangement structure of straight lines or curves in which a plurality of points are connected to each other, thereby having a shape corresponding to the through hole.

[0114] In this case, if Fig.15 As shown in part (a) of FIG. 2 , from a plane view, the laser scanning processing pattern 225 may have a straight line shape in which a plurality of points are connected to each other, thereby having a shape corresponding to the through hole. The straight line is not limited to being arranged along the x-axis direction or the y-axis direction, and not only an oblique line, but also any straight line arranged along any specific direction can be applied without restriction.

[0115] And, if Fig.15 As shown in part (b) of FIG. 1 , from a plane view, the laser scanning processing pattern 225 may have a curve shape in which a plurality of points are connected to each other, thereby having a shape corresponding to the through hole. The curve is arranged in a shape that is bent at least once, and any part of the curve is applicable.

[0116] And, if Fig.15 As shown in part (c), from a plane view, the laser scanning processing pattern 225 can have a straight line shape in which multiple points are connected to each other, and has various structures such as at least two straight lines connected to or intersecting each other, thereby having a shape corresponding to the through hole.

[0117] As reference Fig.15 As described in parts (a) to (c) of the present invention, when the laser scanning processing pattern 225 is formed into a straight line or curve arrangement structure having a plurality of points connected to each other to have a shape corresponding to the through hole, the number of points of the laser scanning processing pattern 225 can be increased, and the number of regions where the properties of the workpiece 210 are changed can be further increased to increase the channels that are easier to penetrate the etchant, thereby further shortening the etching time. Ultimately, not only can the etching time be significantly shortened, but also the consumption of the etchant can be significantly reduced, thereby maximizing the production efficiency.

[0118] Forming through holes by wet etching

[0119] like Figure 7 , Fig.11 and Fig.12 As shown, in the through hole forming step S240 based on wet etching, the laser scanning processing pattern ( Fig.10 The workpiece 210 of 225) is etched to form through holes TH in each through hole forming area.

[0120] More specifically, the through hole forming step S240 based on wet etching can be subdivided into a process of forming a plurality of etching grooves and a process of forming a through hole.

[0121] In the process of forming multiple etching grooves, the etchant is infiltrated into the laser scanning processing pattern 225 of the workpiece 210 whose properties have been locally changed by laser processing, so that a portion of the exposed surface of the workpiece 210 is removed along the thickness direction, thereby forming multiple etching grooves E.

[0122] In this step, etching may be performed by wet etching using a fluorinated etchant, a non-fluorinated etchant, or the like, but this is merely exemplary, and any etchant that can etch the workpiece 210 may be used without limitation.

[0123] More preferably, the etching is preferably performed by wet etching using one or more etchants selected from the group consisting of hydrofluoric acid (HF), ammonium fluoride (NH4F), potassium hydroxide (KOH) and sodium hydroxide (NaOH).

[0124] Then, in the process of forming the through hole, as the etchant penetrates toward the center of the thickness of the workpiece 210 along the plurality of etching grooves E, the stacked portion S of the workpiece 210 whose properties are changed between the laser scanning processing patterns 225 naturally falls off or corrodes, thereby forming the through hole TH. For example, when the size of the properties changed by laser processing is large, the stacked portion S can be naturally fallen off and removed during the etching process, and when the size of the properties changed by laser processing is small, it will be naturally corroded.

[0125] As described above, in the present invention, as time goes by, since the multiple etching grooves E will be further etched by the etchant, the stack portion S of the workpiece 210 with changed properties located between the multiple etching grooves E will be removed due to natural falling off or corrosion. Therefore, compared with the general through-hole forming method, the through-hole TH of the desired size can be formed in a sufficiently short time.

[0126] The through holes TH located in each through hole forming region may be formed on the same plane. Also, the through holes TH located in each through hole forming region may be formed on different planes. In addition, the through holes TH located in each through hole forming region may be partially formed on the same plane and partially formed on different planes.

[0127] The through hole TH of the present invention may have a diameter of 1 μm to 50 cm, but is not limited thereto. In the present invention, the diameter not only means the maximum length of a circular through hole TH, but also can be broadly interpreted as the maximum length of a polygonal, elliptical, or other through hole TH.

[0128] The surface of the through hole TH may have a first diameter d1 , and the inner center may have a second diameter d2 smaller than the first diameter d1 . Finally, the inner wall of the through hole TH may have an acute taper angle relative to the horizontal plane of the workpiece 210 .

[0129] Furthermore, the surface portion of the through hole TH may have a first diameter d1, and the inner center portion may have a second diameter d2 larger than the first diameter d1. Finally, the inner wall of the through hole TH may have an obtuse taper angle relative to the horizontal plane of the workpiece 210. Therefore, the inner wall of the through hole TH may have an acute to obtuse taper angle relative to the horizontal plane of the workpiece 210.

[0130] That is, in a general through-hole forming method, since the Bessel beam irradiates each through-hole forming area of ​​the workpiece, the Bessel beam irradiated along the thickness direction of the workpiece performs intensive laser processing on only one processing position. Therefore, if there are surface defects such as foreign matter and stains on the workpiece at the processing position, it is likely that the internal properties of the workpiece made of brittle material cannot be uniformly changed. This will eventually lead to poor through-holes during wet etching, which will not only affect the uniformity of the size or shape of multiple through-holes located in each through-hole forming area, but also make the size between the surface diameter of the through-hole and the center diameter of the through-hole during wet etching uneven, thereby becoming a factor in reducing the taper angle and causing a decrease in product quality.

[0131] In contrast, the through hole forming method of the embodiment of the present invention performs wet etching in a state where each through hole forming area of ​​the workpiece 210 is irradiated with a Bessel beam BB in a scanning manner in a shape that is the same or similar to the shape of the through hole TH to form a laser scanning processing pattern 225. Therefore, a plurality of etching grooves E can be formed on the workpiece 210 with a minimum etching time.

[0132] In this case, as time goes by, the multiple etching grooves E formed will be further etched by the etchant, and the stack part S of the workpiece 210 with changed properties located between the multiple etching grooves E will be removed due to natural falling off or corrosion. Therefore, compared with the general through-hole forming method, the through-hole TH of the required size can be formed in a very short time.

[0133] In addition, in the fast and precise through-hole forming method using infrared laser in an embodiment of the present invention, wet etching is performed while each through-hole forming area of ​​the workpiece 210 is sequentially irradiated with a Bessel beam BB in a scanning manner to form a laser scanning processing pattern 225. Therefore, even if a part of the laser processing points in each laser scanning processing pattern 225 located in each through-hole forming area is poor due to stains or foreign matter on the outside of the workpiece 210, causing part of the properties of the workpiece 210 to change unevenly, other laser processing points are arranged around it. Therefore, it will not be greatly affected during wet etching, thereby ensuring the product quality of the through hole TH.

[0134] Finally, the rapid and precise through-hole forming method using infrared laser according to the embodiment of the present invention can ensure that the diameter d1 of the surface portion of the through-hole TH and the diameter d2 of the center portion of the through-hole TH remain uniform during wet etching.

[0135] Furthermore, in a general through-hole forming method, a Bessel beam is irradiated on each through-hole forming area of ​​the workpiece to form a laser processing point, and the through-hole TH is formed by gradually expanding the hole size of the laser processing point through wet etching using an etchant. Therefore, there are limitations in the shape diversification of the through-hole TH.

[0136] On the contrary, the method for forming a through hole quickly and precisely using an infrared laser in an embodiment of the present invention implements wet etching by utilizing a laser scanning processing pattern 225 having an arrangement structure separated by regular or irregular intervals, so that the through holes having a shape that is actually the same as or similar to the laser scanning processing pattern 225 can also have a variety of shapes, thereby achieving diversification.

[0137] Accordingly, the method for forming a through hole quickly and precisely using an infrared laser according to an embodiment of the present invention can be applied to the fields of semiconductors, displays, solar cells, etc., but is not limited thereto. Obviously, as long as it is a field covered by the technology of forming through holes on brittle materials, it can be applied without restriction.

[0138] Through the above process (step S210 to step S240), the method for forming a rapid and precise through hole using an infrared laser according to an embodiment of the present invention can be completed.

[0139] As described above, the rapid and precise through-hole forming method using infrared laser in an embodiment of the present invention utilizes a mirror structure combined with at least one driving unit to scan and sequentially irradiate a modulated Bessel light beam to the workpiece to rapidly and precisely micro-process it into various sizes or shapes.

[0140] As described above, the method for forming a through hole quickly and precisely using an infrared laser in an embodiment of the present invention adopts a scanning method for laser processing by adjusting the reflection angle of a mirror structure combined with at least one driving unit. Therefore, unlike a general through hole forming method in which only a worktable is moved, not only can the stabilization time during laser processing be shortened to less than about 10ms, but also the method will not be affected by the size of the workpiece being processed by the laser.

[0141] Therefore, compared with a general through-hole forming method, the rapid and precise through-hole forming method using infrared laser according to an embodiment of the present invention can perform laser processing at a speed more than 100 times, thereby greatly improving production efficiency.

[0142] In addition, the fast and precise through-hole forming method using infrared laser in the embodiment of the present invention can quickly and precisely control the processing position of the workpiece, and can perform wet etching in a state where the internal properties of the workpiece are partially changed so that it has the same or similar size or shape as the through-hole, which can significantly shorten the etching time, thereby reducing the cost of etching agent consumption, and thus can improve the uniformity of the quality of multiple through-holes formed on the entire workpiece while improving production efficiency. Therefore, since the stacked body part of the workpiece with changed properties located between the multiple etching grooves in the present invention will be removed due to natural shedding or corrosion, compared with the general through-hole forming method, a through-hole of a desired size can be formed in a very short time.

[0143] In addition, the fast and precise through-hole forming method using infrared laser of the embodiment of the present invention performs wet etching in a state where a Bessel beam is sequentially irradiated to each through-hole forming area of ​​the workpiece in a scanning manner to form a laser scanning processing pattern. Therefore, in the present invention, even if a part of the laser scanning processing patterns located in each through-hole forming area is defective due to stains and foreign matter outside the workpiece, so that the partial properties of the workpiece change unevenly, other laser scanning processing patterns are arranged around it, so that it can be not greatly affected during wet etching, and the product quality of the through-hole is ensured.

[0144] Finally, the rapid and precise through-hole forming method using infrared laser according to the embodiment of the present invention can ensure that the diameter of the surface portion of the through-hole and the diameter of the center portion of the through-hole remain uniform during wet etching.

[0145] Furthermore, the method for forming a through hole quickly and precisely using an infrared laser in an embodiment of the present invention implements wet etching by using a laser scanning processing pattern having an arrangement structure separated by regular or irregular intervals, so that the through holes having a shape that is actually the same as or similar to the laser scanning processing pattern can also have a variety of shapes, thereby achieving diversification.

[0146] Example

[0147] The following will further describe the composition and function of the present invention in detail through the preferred embodiments of the present invention. However, these are only proposed as preferred embodiments of the present invention and should not be interpreted as limiting the present invention in any sense.

[0148] The contents not described here are contents that can be technically inferred by a person skilled in the art, so their description is omitted.

[0149] 1. Make a through hole test piece

[0150] Example 1

[0151] After the infrared laser device is directed to the upper portion of the glass substrate having a thickness of 0.55 mm, the laser beam emitted from the infrared laser device is modulated into a Bessel beam. Then, the modulated Bessel beam is sequentially irradiated to each through-hole forming area of ​​the glass substrate in a scanning manner to form a laser scanning processing pattern that changes the properties of the workpiece. In this case, the laser scanning processing pattern is controlled so that a plurality of laser processing points have a circular shape that is regularly spaced at a predetermined interval.

[0152] Then, the glass substrate on which the laser scanning pattern was formed was wet-etched at a rate of 2 μm / min for 13 minutes using a hydrofluoric acid etchant to form a through hole.

[0153] Example 2

[0154] The through-holes were formed in the same manner as in Example 1 except that the wet etching was performed at a rate of 1.5 μm / min for 18 minutes.

[0155] Example 3

[0156] The through-holes were formed in the same manner as in Example 1 except that the wet etching was performed at a rate of 2.5 μm / min for 9 minutes.

[0157] Comparative Example 1

[0158] After aligning the laser Bessel beam optical modulation device with the upper part of the glass substrate with a thickness of 0.65 mm, the laser beam emitted from the laser Bessel beam optical modulation device is modulated into a Bessel beam. Then, each through-hole forming area of ​​the glass substrate is irradiated with the modulated Bessel beam to form a laser processing point that changes the properties of the workpiece.

[0159] Then, the glass substrate on which the laser processing points were formed was wet-etched at a rate of 2 μm / min for 80 minutes using a hydrofluoric acid etchant to form through holes.

[0160] Comparative Example 2

[0161] Through holes were formed in the same manner as in Comparative Example 1 except that wet etching was performed at a rate of 2.5 μm / min for 68 minutes.

[0162] 2. Physical property evaluation

[0163] Table 1 shows the evaluation results of the physical properties of the through-hole test pieces prepared according to Examples 1 to 3 and Comparative Examples 1 and 2.

[0164] Table 1

[0165]

[0166]

[0167] As shown in Table 1, it can be confirmed that the through-hole test pieces prepared according to Examples 1 to 3 can form through-holes within an etching time of less than 20 minutes based on a glass substrate having a thickness of 0.55 mm before etching.

[0168] On the contrary, it was confirmed that the through-hole test pieces prepared according to Comparative Examples 1 and 2 required an etching time of more than 1 hour to form the through-holes based on the glass substrate having a thickness of 0.65 mm before etching.

[0169] 2. Observe microscopic tissues

[0170] Fig.16 The process picture is to show the formation process of the through hole made according to Comparative Example 1. Fig.17 The figure is a process picture showing the formation process of the through hole manufactured according to Example 1.

[0171] like Fig.16 As shown in part (a) of FIG. 1 , it can be confirmed that in Comparative Example 1, the modulated Bessel beam is irradiated onto the glass substrate 110 , and a laser processing spot 125 that changes the properties of the glass substrate 110 is formed along the thickness direction of the glass substrate 110 .

[0172] Afterwards, if Fig.16 As shown in part (b) of FIG. 1 , it can be confirmed that an etching groove E is formed as the etching agent gradually penetrates into the part where the properties of the glass substrate 110 where the laser processing point 125 is located. In this case, Fig.16 Part (b) shows the state after 10 minutes of wet etching. It can be confirmed that in the process of wet etching the part of the glass substrate 110 where the property is changed to form the etching groove E, although the etching speed of the part where the property is changed is significantly slow, part of the surface of the glass substrate 110 is etched and removed together.

[0173] Afterwards, if Fig.16 As shown in parts (c) and (d) of FIG. 1 , it can be confirmed that as the wet etching progresses over time, the etching groove gradually expands, and a through hole TH penetrating the interior of the glass substrate 110 is formed.

[0174] In this case, Fig.16 Parts (c) and (d) of FIG. 3 show the state after 80 minutes of wet etching. It can be confirmed that the wet etching radius required to form the through hole TH is large, and a lot of etching time is consumed.

[0175] On the contrary, Fig.17As shown in part (a), it can be confirmed that in Example 1, the modulated Bessel light beam is irradiated on the glass substrate 210 in a scanning manner, and a laser scanning processing pattern 225 that changes the properties of the glass substrate 210 is formed at regular intervals along the thickness direction of the glass substrate 210 at prescribed intervals.

[0176] Afterwards, if Fig.17 As shown in part (b) of FIG. 1 , it can be confirmed that an etching groove E is formed as the etching agent gradually penetrates into the part where the properties of the glass substrate 210 where the laser scanning processing pattern 225 is located. In this case, Fig.17 Part (b) shows the state after 10 minutes of wet etching. It can be confirmed that in the process of wet etching the part of the glass substrate 210 with changed properties to form the etching groove E, although the etching speed of the part with changed properties is significantly slow, part of the surface of the glass substrate 210 is etched and removed together.

[0177] Afterwards, if Fig.17 As shown in parts (c) and (d), it can be confirmed that as the wet etching progresses further over time, the waste part S with changed properties inside the glass substrate 210 located between the multiple etching grooves E is removed due to natural falling off, forming a through hole TH.

[0178] In this case, Fig.17 Parts (c) and (d) of FIG. 3 show the state after the wet etching time is 18 minutes. It can be confirmed that the wet etching radius required to form the through hole TH is significantly reduced, so the etching time is significantly shortened.

[0179] Although the above description is centered on the embodiments of the present invention, a person skilled in the art may make various modifications and variations to the present invention. Such modifications and variations, as long as they do not exceed the scope of the technical concept provided by the present invention, belong to the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the attached invention claims.

[0180] Description of Reference Numerals

[0181] S210: Infrared laser device alignment steps

[0182] S220: Laser beam modulation steps

[0183] S230: Laser scanning processing pattern forming step

[0184] S240: through-hole forming step by wet etching.

Claims

1. A method for forming a rapid and precise through hole using an infrared laser, characterized in that: include: Step (a), aligning an infrared laser device with the upper portion of a workpiece; Step (b), modulating the laser beam emitted from the infrared laser device into a Bessel beam; Step (c), performing laser processing by sequentially irradiating each through hole forming area of ​​the workpiece with the modulated Bessel light beam in a scanning manner, thereby forming a laser scanning processing pattern that partially changes the properties of the workpiece; and Step (d) is to etch the workpiece on which the laser scanning processing pattern is formed to form through holes in each of the through hole forming regions.

2. The method for forming a rapid and precise through hole using an infrared laser according to claim 1, characterized in that: The laser beam uses ultrashort laser light having a wavelength of 900 nm to 1200 nm and a pulse width of 50 femtoseconds to 50 picoseconds.

3. The method for forming a rapid and precise through hole using an infrared laser according to claim 1, characterized in that: In the above-mentioned laser scanning processing pattern, the individual dots formed by the above-mentioned laser processing have an arrangement structure separated at regular or irregular intervals to form a shape corresponding to the above-mentioned through hole when viewed from a plane.

4. The method for forming a rapid and precise through hole using an infrared laser according to claim 3, characterized in that: Viewed from a planar perspective, in the above-mentioned laser scanning processing pattern, the individual points formed by the above-mentioned laser processing are separated by regular or irregular intervals of less than 20 μm and have an arrangement structure corresponding to the above-mentioned through holes in one or more shapes selected from polygons including triangles, quadrilaterals, pentagons, hexagons, octagons and stars, circles and ellipses.

5. The method for forming a rapid and precise through hole using an infrared laser according to claim 3, characterized in that: From a plane perspective, the above laser scanning processing patterns include: The first laser scanning processing pattern is arranged at regular or irregular intervals to have a shape corresponding to the through hole; and At least one second laser scanning processing pattern is arranged inside the first laser scanning processing pattern. 6 . According to the method for forming a rapid and precise through-hole using an infrared laser as claimed in claim 5 , the second laser scanning processing pattern has an arrangement structure having the same shape or a different shape from that of the first laser scanning processing pattern.

7. The method for forming a rapid and precise through hole using an infrared laser according to claim 1, characterized in that: When viewed from a plane, the laser scanning processing pattern has an arrangement structure of straight lines or curves in which a plurality of points are connected to each other, so as to have a shape corresponding to the through hole.

8. The method for forming a rapid and precise through hole using an infrared laser according to claim 1, characterized in that: The workpiece is a flat glass substrate.

9. The method for forming a rapid and precise through hole using an infrared laser according to claim 1, characterized in that: In the step (c), the scanning laser processing is performed by scanning using a mirror structure coupled with at least one driving unit, so that the scanning laser processing is performed within a stabilization time of 10 ms or less.

10. The method for forming a rapid and precise through hole using an infrared laser according to claim 1, characterized in that: In the above step (d), the through holes located in the through hole forming regions are formed on the same plane, or at least a part of them are formed on different planes.

11. The method for forming a rapid and precise through hole using an infrared laser according to claim 1, characterized in that: In the step (d), the etching is performed by wet etching using at least one etchant selected from a fluorinated etchant and a non-fluorinated etchant.

12. The method for forming a rapid and precise through hole using an infrared laser according to claim 1, characterized in that: The above step (d) comprises: Step (d-1), infiltrating an etchant into the laser scanning processing pattern of the workpiece whose properties have been locally changed by the laser processing, so that a portion of the exposed surface of the workpiece is removed along the thickness direction, thereby forming a plurality of etching grooves; and In step (d-2), as the etchant penetrates along the plurality of etching grooves toward the center of the thickness of the workpiece, the stacked portion of the workpiece with changed properties in the space between the laser scanning processing patterns naturally falls off or corrodes, thereby forming a through hole.

13. The method for forming a rapid and precise through hole using infrared laser according to claim 12, characterized in that: The inner wall of the through hole has a taper angle ranging from an acute angle to an obtuse angle relative to a horizontal plane of the workpiece.

Images