Laser processing apparatus

Abstract

This laser processing apparatus (100) performs laser processing in which laser light (3) is condensed by an fθ lens (4) to irradiate a workpiece (25). The laser processing apparatus (100) comprises a protection window (5), a holder (6), a first air nozzle (7) for ejecting first air (A1), and a dust collection device (40) including: a dust collection duct (12) having a first opening (12a), a second opening (12b), a second air nozzle (9) for ejecting second air (A2), and a duct exhaust port (11); and a suction device (20) for sucking the second air (A2). The first opening (12a) and the second opening (12b) have an opening shape capable of surrounding the protection window (5), and the second air nozzle (9) ejects the second air (A2) to a range wider than the diameter of the protection window (5).

Description

Laser Processing Equipment

[0001] The present disclosure relates to a laser processing apparatus.

[0002] Laser processing machines that perform high-speed drilling or cutting on workpieces such as printed wiring boards are equipped with a lens and a protective window to protect the lens in the processing head. Such laser processing machines focus the laser light output from the laser oscillator with a focusing lens to perform laser processing on the workpiece. The protective window shields the lens from spatter, interfering gas, and dust generated during laser processing. Exposure to spatter, interfering gas, and dust can cause the surface of the protective window to deteriorate or become damaged, resulting in cleaning, replacement, or processing defects.

[0003] Patent Document 1 discloses a laser cutting device that includes a cover glass that protects a focusing lens from debris that scatters when a workpiece is laser-processed, an air injection nozzle that injects air toward the cover glass to remove the debris, a downflow generating unit that generates a downflow that prevents debris from entering the cover glass, an outside air introduction path, and a suction path. The air injection nozzle and the downflow generating unit guide debris that has scattered upward downward without reaching the cover glass, and the debris is collected in the suction path.

[0004] Japanese Patent Application Laid-Open No. 2022-046068

[0005] In Patent Document 1, an air curtain is used that introduces outside air using a configuration that includes an outside air introduction path and a suction flow path, but because the air does not flow in a straight line and the air volume is small, there is variation in the protective ability of the air curtain and the protective performance of the protective window is reduced.

[0006] The present disclosure has been made in view of the above, and has an object to provide a laser processing device that improves the protective performance of a protective window and achieves stable laser processing.

[0007] To solve the above-mentioned problems and achieve the object, a laser processing apparatus according to the present disclosure performs laser processing by focusing laser light with a focusing lens and irradiating the focused light onto a workpiece. The laser processing apparatus includes a protective window provided downstream of the focusing lens in the optical path, a holder for holding the focusing lens and the protective window, a first air nozzle for spraying first air toward the protective window, a dust collection duct having a first opening and a second opening downstream of the first opening in the optical path through which the laser light passes, a second air nozzle for spraying second air, and a duct exhaust port serving as a recovery port for the second air, and a dust collection device for sucking the second air from the duct exhaust port. The first opening and the second opening have opening shapes large enough to surround the protective window. The second air nozzle sprays second air over an area wider than the diameter of the protective window.

[0008] The laser processing apparatus of the present disclosure has the effect of improving the protective performance of the protective window and realizing stable laser processing.

[0009] FIG. 1 is a diagram showing a schematic configuration of a laser processing apparatus according to an embodiment; FIG. 2 is a bottom view showing a configuration of a dust collection duct of the laser processing apparatus according to an embodiment;

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A laser processing apparatus according to an embodiment will be described in detail below with reference to the accompanying drawings.

[0011] FIG. 1 is a diagram illustrating a schematic configuration of a laser processing apparatus 100 according to an embodiment. FIG. 2 is a bottom view illustrating the configuration of a dust collection duct 12 of the laser processing apparatus 100 according to the embodiment. The laser processing apparatus 100 includes a laser oscillator 1, a reflecting mirror 2, an fθ lens 4 as a condenser lens, a protective window 5, a holder 6 as a first holder, a dust sensor 13, a Z-axis box 16 as a second holder, a dust collection device 40, a first high-pressure air supply source 21 as a first air supply source, a second high-pressure air supply source 22 as a second air supply source, a control device 24, and an XY table 26. The dust collection device 40 includes a dust collection duct 12 and a suction device 20. The laser processing apparatus 100 performs laser processing by condensing a laser beam 3 with an fθ lens 4 and irradiating the laser beam 3 onto a workpiece 25. FIG. 1 illustrates an X, Y, and Z coordinate system. While the Z direction is described as the up-down direction, other implementations are possible.

[0012] A laser oscillator 1 emits laser light 3 as a pulse wave. The laser light 3 emitted from the laser oscillator 1 is guided to an fθ lens 4 via a reflecting mirror 2. The reflecting mirror 2 reflects the laser light 3 and guides it downstream on the optical path. The reflecting mirrors 2 are arranged at various positions on the optical path within the laser processing apparatus 100.

[0013] The fθ lens 4 focuses the laser beam 3 onto the workpiece 25. The workpiece 25, which is the object to be processed, is placed on an XY table 26. The workpiece 25 is, for example, a printed wiring board. The XY table 26 can be moved two-dimensionally in the X and Y directions by a drive mechanism (not shown). The workpiece 25 is drilled or cut by irradiating the laser beam 3 onto the workpiece 25.

[0014] A holder 6 is housed and fixed in the Z-axis box 16. The holder 6 is, for example, cylindrical in shape. The fθ lens 4 and protective window 5 are attached inside the holder 6, and the holder 6 holds the fθ lens 4 and the protective window 5. The protective window 5 is provided below the fθ lens 4, downstream in the optical path. The protective window 5 is provided between the fθ lens 4 and the workpiece 25. The protective window 5 shields the fθ lens 4 from spatter B1, interfering gas B2, or dust B3 generated during processing of the workpiece 25, thereby protecting the fθ lens 4.

[0015] A plurality of first air nozzles 7 are provided on the side of the holder 6. The plurality of first air nozzles 7 are connected to a first high-pressure air supply source 21 via a first air pipe 18. The first air nozzles 7 spray first air A1 toward the protective window 5. That is, the plurality of first air nozzles 7 are provided below the protective window 5 and are inclined obliquely so that high-pressure air is sprayed from diagonally below the protective window 5 toward the protective window 5. This cools the protective window 5 and prevents changes in the refractive index of the protective window 5 due to heat input from the laser beam 3 and resulting processing defects. The first air A1 reflected by the protective window 5 changes direction downward and pushes back spatter B1, interfering gas B2, or dust B3 generated from the workpiece 25.

[0016] A dust collection duct 12 is provided below the holder 6 to prevent spatter B1, interference gas B2, or dust B3 from being released to the outside. The dust collection duct 12 is attached to the underside of the Z-axis box 16 by a first bolt joint 14 and a second bolt joint 15, and is not in contact with the holder 6. That is, a gap 8 is provided between the holder 6 and the dust collection duct 12. Preventing direct contact between the dust collection duct 12 and the holder 6 prevents negative pressure vibrations from a suction device 20, described below, from being transmitted to the fθ lens 4. The distance between the dust collection duct 12 and the Z-axis box 16 can be adjusted by adjusting the vertical nut positions of the first bolt joint 14 and the second bolt joint 15.

[0017] The dust collection duct 12 has a first opening 12a on the upper side through which the laser beam 3 passes and a second opening 12b on the lower side through which the laser beam 3 passes, so that the laser beam 3 can be irradiated onto the workpiece 25. The first opening 12a and the second opening 12b are openings perpendicular to the optical axis of the laser beam 3. FIG. 2 shows the dust collection duct 12 as viewed from below. The dust collection duct 12 includes a second air nozzle 9, which is an outlet for the second air A2, and a duct exhaust port 11, which is an outlet for recovering the second air A2. The second air nozzle 9 is connected to a second high-pressure air supply source 22 via a second air piping 19. Clean second air A2 is supplied from the second high-pressure air supply source 22 to the second air nozzle 9 via the second air piping 19. The clean second air A2 is sprayed from the second air nozzle 9 into the dust collection duct 12 in the X direction so as to intersect with the laser beam 3.

[0018] As shown in FIG. 2 , the second air nozzle 9 has an opening that extends elongately in the Y direction, and the length of the opening of the second air nozzle 9 in the Y direction is greater than the diameter of the protective window 5. That is, the second air nozzle 9 sprays the second air A2 along the surface of the protective window 5 over an area wider than the diameter of the protective window 5. This allows the second air A2 to be sprayed from the second air nozzle 9 parallel to the protective window 5 over an area wider than the outer diameter of the protective window 5. The second air nozzle 9 has an angle adjustment mechanism with respect to the Z direction, which allows adjustment to an optimal air emission angle. As shown in FIG. 2 , it is desirable for the duct exhaust port 11 to have an opening that extends elongately in the Y direction, similar to the second air nozzle 9.

[0019] The duct exhaust port 11 is connected to a suction device 20 via an air pipe 17. The suction device 20 generates a suction force (negative pressure). The suction device 20 generates a negative pressure A3 from the duct exhaust port 11 and collects spatter B1, interfering gas B2, and dust B3 in the dust collection duct 12. In this way, the second air nozzle 9, the duct exhaust port 11, and the suction device 20 realize an air curtain function.

[0020] As shown in FIG. 2 , the upper first opening 12a has a circular shape, and the lower second opening 12b has a shape that combines a semicircular shape and a rectangular shape. The upper first opening 12a has a circular shape with a diameter larger than the diameter of the protective window 5. The lower second opening 12b has a semicircular shape on the left side (−X side) with a diameter larger than the diameter of the protective window 5, and a rectangular shape on the right side (+X side) with two sides in the Y direction larger than the diameter of the protective window 5 and two sides in the X direction larger than the radius of the protective window 5. In this way, the first opening 12a and the second opening 12b have opening shapes large enough to surround the protective window 5.

[0021] As shown in FIG. 2 , the second opening 12b is formed so that the area of ​​the opening region on the right side (+X side) of the center line 30 extending through the protective window 5 in the Y direction is larger than the area of ​​the opening region on the left side (−X side) of the center line 30. Regarding the second opening 12b, as long as the opening area on the duct exhaust port 11 side of the center line 30 is larger than the opening area on the second air nozzle 9 side of the center line 30, other shapes may be used for the opening shape on the duct exhaust port 11 side of the center line 30 and the opening shape on the second air nozzle 9 side of the center line 30. The center line 30 is a straight line extending in the ±Y directions from the X-direction position through which the laser light 3 passes. The center line 30 can also be considered to be a straight line extending in the ±Y directions from the circular center of the protective window 5. When the first opening 12a has a circular shape, the center line 30 can also be considered to be a straight line extending in the ±Y directions from the circular center of the first opening 12a.

[0022] The dust sensor 13 measures the amount of dust in the dust collection duct 12. The dust to be measured includes spatter B1, interference gas B2, and dust B3. It is preferable to install the dust sensor 13 near the duct exhaust port 11. The amount measured by the dust sensor 13 is input to the control device 24. The control device 24 is connected to the dust sensor 13, the suction device 20, the first high-pressure air supply source 21, and the second high-pressure air supply source 22. The control device 24 stores information about the laser processing conditions and the workpiece 25. The information about the workpiece includes the material and thickness of the workpiece. The control device 24 controls the air volume of the first air nozzle 7 from the first high-pressure air supply source 21, the air volume of the second air nozzle 9 from the second high-pressure air supply source 22, and the suction force (negative pressure) of the suction device 20 based on the measurement value of the dust sensor 13, the laser processing conditions, and the workpiece information.

[0023] In this embodiment, the first opening 12a and the second opening 12b have an opening shape large enough to surround the protective window 5. Furthermore, the second air nozzle 9 sprays the second air A2 along the surface of the protective window 5 over an area wider than the diameter of the protective window 5. Therefore, in this embodiment, the second air A2 travels more linearly, the air volume increases, the protective ability of the air curtain is stabilized, and the protective performance of the air curtain for the protective window 5 is improved.

[0024] Furthermore, at the second opening 12b, the opening area on the duct exhaust port 11 side of the center line 30 is larger than the opening area on the second air nozzle 9 side of the center line 30, so that the generation of turbulence on the duct exhaust port 11 side in the dust collection duct 12 can be suppressed, and a decrease in dust collection efficiency and air curtain strength can be prevented.

[0025] In addition, in this embodiment, a gap 8 is provided between the dust collection duct 12 and the holder 6 to prevent direct contact between the dust collection duct 12 and the holder 6. This prevents negative pressure vibrations from the suction device 20 from being transmitted to the fθ lens 4, thereby preventing processing defects.

[0026] Furthermore, in the embodiment, clean first air A1 and second air A2 are supplied from the first high-pressure air supply source 21 and the second high-pressure air supply source 22, so that clean first air A1 and second air A2 can be supplied even when the outside air is filled with spatter, interfering gases, and dust, thereby reducing the risk of damage to the protective window 5.

[0027] Furthermore, in the embodiment, the control device 24 controls the air volume of the first air nozzle 7 from the first high-pressure air supply source 21, the air volume of the second air nozzle 9 from the second high-pressure air supply source 22, and the suction force (negative pressure) of the suction device 20 based on the measurement value of the dust sensor 13, the laser processing conditions, and information about the workpiece to be processed, thereby optimizing the protective capability of the protective window 5. By optimizing the protective capability of the protective window 5 when the processing conditions, the workpiece to be processed, or the factory environment change, it is possible to prevent damage to the protective window 5 and the accumulation of spatter B1, interfering gas B2, and dust B3 in the environment or on the workpiece 25.

[0028] The configurations shown in the above embodiments are examples of the contents of the present disclosure, and may be combined with other known technologies, or embodiments may be combined with each other, and some of the configurations may be omitted or modified within the scope of the gist of the present disclosure.

[0029] 1 Laser oscillator, 2 Reflecting mirror, 3 Laser light, 4 fθ lens, 5 Protective window, 6 Holder, 7 First air nozzle, 8 Gap, 9 Second air nozzle, 11 Duct exhaust port, 12 Dust collection duct, 12a First opening, 12b Second opening, 13 Dust sensor, 14 First bolt joint, 15 Second bolt joint, 16 Z-axis box, 17 Air piping, 18 First air piping, 19 Second air piping, 20 Suction device, 21 First high-pressure air supply source, 22 Second high-pressure air supply source, 24 Control device, 25 Workpiece, 26 XY table, 30 Center line, 40 Dust collection device, 100 Laser processing device, A1 First air, A2 Second air, B1 Spatter, B2 Interfering gas, B3 Dust.

Claims

1. A laser processing apparatus for performing laser processing by focusing laser light with a focusing lens and irradiating the laser light on a workpiece, comprising: a protective window provided downstream of the optical path of the focusing lens; a holder for holding the focusing lens and the protective window; a first air nozzle for spraying first air toward the protective window; a dust collection duct having a first opening and a second opening downstream of the optical path from the first opening through which the laser light passes, a second air nozzle for spraying second air, and a duct exhaust port which is a recovery port for the second air; and a dust collection device having a suction device for sucking the second air from the duct exhaust port, wherein the first opening and the second opening have an opening shape large enough to surround the protective window, and the second air nozzle sprays the second air over an area wider than the diameter of the protective window.

2. The laser processing device according to claim 1, characterized in that the second air nozzle injects the second air along the surface of the protective window.

3. The laser processing device according to claim 1 or 2, characterized in that the second opening has an opening area from the center line to the duct exhaust port side larger than an opening area from the center line to the second air nozzle side.

4. A laser processing device as described in any one of claims 1 to 3, characterized in that the first holder, which is the holder, is stored and fixed in the second holder, and the dust collection duct is fixed to the downstream side of the optical path of the second holder with a gap between it and the first holder.

5. A laser processing apparatus as described in any one of claims 1 to 4, characterized in that it comprises: a first air supply source which supplies clean first air to the first air nozzle; and a second air supply source which supplies clean second air to the second air nozzle.

6. A laser processing apparatus as claimed in any one of claims 1 to 5, characterized in that it comprises: a dust sensor which measures the amount of dust in the dust collection duct; and a control device which controls the air volume of the first air nozzle, the air volume of the second air nozzle and the suction force of the dust collection device based on the measurement value of the dust sensor, the processing conditions of the laser processing and information on the workpiece.

7. The laser processing device according to claim 4, further comprising a mechanism for adjusting the distance between the second holder and the dust collection duct.

8. A laser processing device as claimed in any one of claims 1 to 7, characterized in that it has a mechanism for adjusting the angle of the second air with respect to a direction perpendicular to the surface of the protective window.

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