KR102623097B1 - Laser beam drilling device - Google Patents

Abstract

The present invention relates to a laser drilling device. This laser drilling device includes a variable focus module that changes the focal length of the laser beam; When the optical axis at which the laser beam passing through the variable focus module is incident is referred to as a reference optical axis, an optical axis moving unit moves a predetermined distance with respect to the reference optical axis to emit the laser beam; a first driving unit that rotates the optical axis moving unit; A first focusing lens for focusing the laser beam that has passed through the optical axis moving unit, wherein the optical axis moving unit is rotated by the driving unit and the focal length of the laser beam is gradually changed to longer by the variable focus module. While doing so, the surface of the workpiece is drilled.

Description

Laser drilling device {Laser beam drilling device}

The present invention relates to a laser drilling device, and in particular, laser drilling that allows rapid hole processing by moving the optical axis of an incident laser beam to change the irradiated position on the surface of the workpiece and rotating the optical axis moving part. It's about devices.

Figure 1 shows an example of a laser drilling device according to the prior art. The laser drilling device according to the prior art includes a focus variable module (1) that changes the focus of the laser beam, a first scanner module (2) and a second scanner module (3) that change the irradiation position of the laser beam, and a laser beam. It is configured to include a focus lens module (f-theta lens) 4 that collects light. The laser beam that has passed through each of the above devices is irradiated to the irradiation surface 5 of a predetermined workpiece.

Such a conventional laser drilling device has limitations in implementing high-speed drilling because the first and second scanner modules 2 and 3 must be driven simultaneously to change the direction of the laser beam. In addition, when the area to which the laser beam is to be irradiated with respect to the workpiece is large, the laser beam must be irradiated while moving the workpiece placed below the focus lens module 4 using a stage, so it is necessary to move the workpiece. The disadvantage is that the cost of a separate stage increases and its installation is complicated. Additionally, the problem of controlling time delay to move the stage must be resolved.

The present invention was developed to solve the above-mentioned problems. In particular, the optical axis of the incident laser beam can be moved to change the irradiated position on the surface of the workpiece, and the optical axis moving part can be rotated to quickly perform hole processing. The purpose is to provide a laser drilling device that allows

A laser drilling device according to an embodiment of the present invention for achieving the above-described object includes a variable focus module that changes the focal length of a laser beam; When the optical axis at which the laser beam passing through the variable focus module is incident is referred to as a reference optical axis, an optical axis moving unit moves a predetermined distance with respect to the reference optical axis to emit the laser beam; a first driving unit that rotates the optical axis moving unit; A first focusing lens for focusing the laser beam that has passed through the optical axis moving unit, wherein the optical axis moving unit is rotated by the driving unit and the focal length of the laser beam is gradually changed to become longer by the variable focus module. , characterized by drilling the surface of the workpiece.

In addition, the optical axis moving unit preferably includes a first prism that refracts the incident laser beam, and a second prism that is spaced apart from the first prism and arranged upside down with respect to the first prism.

Additionally, it is preferable that the size of the hole formed in the workpiece increases as the distance the laser beam deviates from the reference optical axis increases.

In addition, it is preferable that a scanner that changes the direction of the laser beam irradiated to the surface of the workpiece is provided between the optical axis moving unit and the first focusing lens.

In addition, the first focusing lens is preferably a telecentric lens that irradiates the workpiece perpendicularly regardless of the position of the incident laser beam.

In addition, the first focusing lens is a telecentric lens that irradiates the workpiece perpendicularly regardless of the position of the incident laser beam, and a second focusing lens is provided between the telecentric lens and the workpiece. , Preferably, it includes a second driving unit that moves the second focusing lens so that the scanner moves the second focusing lens in conjunction with the direction in which the scanner irradiates the laser beam.

Additionally, it is desirable to change the position of the optical axis of the laser beam that has passed through the focusing lens by changing the distance between the first prism and the second prism.

The laser drilling device according to an embodiment of the present invention can quickly perform hole processing by moving the optical axis of an incident laser beam to change the irradiated position on the surface of the workpiece and rotating the optical axis moving part. In particular, according to an embodiment of the present invention, it provides the effect of quickly processing a tapered hole.

In addition, the optical axis of the laser beam is changed by the optical axis moving part, and the optical axis moving part is rotated by the first driving part, providing the effect of quickly and easily changing the direction in which the laser beam is irradiated.

In addition, according to an embodiment of the present invention, the area to which the laser beam is irradiated is secured widely using a telecentric lens, thereby providing the effect of securing a large processing area of the workpiece.

In addition, the second focusing lens disposed at the rear end of the telecentric lens makes the focal length of the laser beam shorter than when only the telecentric lens is used, thereby increasing the angle of the laser beam incident on the surface of the workpiece. This provides the effect of facilitating hole processing in a tapered shape with a large inclination.

1 is a conceptual diagram of a conventional laser drilling device,
Figure 2 is a conceptual diagram of a laser drilling device according to an embodiment of the present invention;
Figure 3 is a diagram showing the optical axis moving part rotated 180 degrees in Figure 2;
Figure 4 is a plan view showing the drilling state from Figure 2 to Figure 3;
Figure 5 is a side view of the drilling state in which the optical axis moving part is rotated in Figure 2;
Figure 6 is a diagram showing a state in which the focal length of the laser beam in Figure 2 is changed to f2;
Figure 7 is a side view of the drilling state in which the optical axis moving part is rotated in Figure 6;
Figure 8 is a diagram showing a state in which the focal length of the laser beam in Figure 6 is changed to f3;
Figure 9 is a side view of the drilling state in which the optical axis moving part is rotated in Figure 8;
10 is a conceptual diagram of a laser drilling device according to another embodiment of the present invention;
Figure 11 is a perspective view of a scanner employed in another embodiment of the present invention;
12 is a conceptual diagram of a laser drilling device according to another embodiment of the present invention;
Figure 13 is a block diagram of the main configuration adopted in Figure 12.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings.

Figure 2 is a conceptual diagram of a laser drilling device according to an embodiment of the present invention. Figure 3 is a diagram showing the optical axis moving part rotated 180 degrees in Figure 2, Figure 4 is a plan view showing the drilling state from Figure 2 to Figure 3, and Figure 5 is a diagram showing the optical axis moving part rotated in Figure 2. This is a side view of the drilled state. Figure 6 is a diagram showing a state in which the focal length of the laser beam in Figure 2 has been changed to f2, and Figure 7 is a side view of the state in which the optical axis moving part in Figure 6 has been rotated and drilled. Figure 8 is a diagram showing a state in which the focal length of the laser beam has been changed to f3 in Figure 6, and Figure 9 is a side view of the state in which the optical axis moving part in Figure 8 has been rotated and drilled.

The laser drilling device according to an embodiment of the present invention includes a variable focus module 10, an optical axis moving unit 20, a first driving unit 30, and a first focusing lens 40.

The variable focus module 10 is provided to change the focal length of the laser beam. The variable focus module 10 includes a plurality of lenses whose distances between each other are variable. By adjusting the distance between the lenses, the focal length of the laser beam passing through the variable focus module 10 can be varied.

For example, the variable focus module 10 may include a concave lens and a convex lens arranged side by side in the optical path direction of the laser beam, and a moving module (not shown) that moves the position of the concave lens or the convex lens. . Accordingly, by adjusting the distance between the concave lens and the convex lens, the focal length of the laser beam passing through the variable focus module 10 can be adjusted. The laser beam passing through the variable focus module 10 may proceed in parallel, divergence, or focus.

When the optical axis at which the laser beam passing through the variable focus module 10 is incident is called the reference optical axis (RA), the optical axis moving unit 20 is moved by a predetermined distance with respect to the reference optical axis (RA). It is provided to emit the laser beam. The laser beam is refracted while passing through the optical axis moving unit 20, and the path of the laser beam is changed.

Specifically, according to this embodiment, the optical axis moving unit 20 includes a first prism 21 and a second prism 22.

As shown in Figure 2, the first prism 21 refracts the incident laser beam. Based on Figure 2, the laser beam is refracted downward by a predetermined angle while passing through the first prism 21. The second prism 22 is arranged to be spaced apart from the first prism 21, and is arranged upside down with respect to the first prism 21. That is, the second prism 22 is arranged in an axisymmetric structure with respect to the first prism 21.

The laser beam that has passed through the first prism 21 is secondarily refracted at the second prism 22. As shown in Figure 2, the optical axis of the laser beam that has passed through the second prism 22 is moved away from the reference optical axis (RA) by a predetermined distance d1, thereby changing the path of the laser beam. .

Figure 2 shows a case where the laser beam passing through the variable focus module 10 proceeds horizontally, and the optical axis of the laser beam passing through the optical axis moving unit 20 is a predetermined distance d1 from the reference optical axis RA. moves in parallel. In Figure 2, the width of the two-dot chain line is a simplified illustration of the size of the laser beam, and the optical axis of the laser beam that is refracted while passing through the optical axis moving unit 20 is indicated by a dotted line. Meanwhile, according to this embodiment, the first and second prisms 21 and 22 have a trapezoidal cross-section, but the first and second prisms 21 and 22 may have a triangular cross-section.

When the distance between the first prism 21 and the second prism 22 changes, the position of the optical axis of the laser beam changes. Referring to Figure 2, when the distance D between the first and second prisms increases, the distance d1 between the optical axis VA of the laser beam passing through the optical axis moving unit 20 and the reference optical axis RA becomes It increases further, and thus the position of the optical axis passing through the first focusing lens 40 changes.

The first driving unit 30 is provided to rotate the optical axis moving unit 20.

According to this embodiment, the first driving unit 30 rotates the optical axis moving unit 20 with the reference optical axis RA as the central axis. Figure 3 shows a state in which the first driving unit 30 rotates the optical axis moving unit 20 by 180°.

As shown in Figure 3, when the optical axis moving unit 20 is rotated by 180° by the first driving unit 30, the optical axis VA of the laser beam passing through the second prism 22 is In the state before the optical axis moving unit 20 rotates 180° (state of FIG. 2), it rotates half a turn around the reference optical axis RA and is positioned on the opposite side. That is, the optical axis VA of the laser beam rotates by 180° with respect to the reference optical axis RA. Figure 4 shows a state in which the optical axis (VA) of the laser beam is rotated by 180° and drilled as a semicircle.

When the first driving unit 30 continuously rotates the optical axis moving unit 20, the optical axis VA of the laser beam rotates around the reference optical axis RA, and the laser beam is transmitted to the workpiece ( The surface of the workpiece 80 is drilled while drawing a circle on the surface of the workpiece 80.

By adjusting the distance between the first prism 21 and the second prism 22, the distance d1 at which the optical axis VA of the laser beam deviates from the reference optical axis RA can be adjusted. For example, if the distance between the first prism 21 and the second prism 22 is increased, the optical axis VA of the laser beam moves farther to the reference optical axis RA.

Therefore, as the distance the laser beam deviates from the reference optical axis (RA) increases, the size of the hole formed in the workpiece 80 can be processed to be larger. That is, after moving the optical axis of the laser beam from the reference optical axis (RA), when the optical axis moving unit 20 is rotated by the first driving unit 30, the optical axis of the laser beam is separated from the reference optical axis (RA). A hole with a radius can be machined on the surface of the workpiece 80.

The first focusing lens 40 is provided to focus the laser beam that has passed through the optical axis moving unit 20. The first focusing lens 40 refracts and focuses the laser beam that has passed through the optical axis moving unit 20 to form a focus on the surface of the workpiece 80. The first focusing lens 40 may adopt a known configuration.

With this configuration, the laser drilling device according to an embodiment of the present invention rotates the optical axis moving unit 20 by the first driving unit 30 and moves the laser beam by the variable focus module 10. While gradually changing the focal length to longer, the surface of the workpiece 80 is drilled.

Specifically, the description will be made with reference to the drawings.

Figures 2, 3, and 5 show that a hole with a radius of R1 is drilled on the surface of the workpiece 80 with respect to the reference optical axis RA. 2, 3, and 5, the focal length of the laser beam is f1, and the focus is formed on the surface (front) 81 of the workpiece 80. As the optical axis moving unit 20 rotates, the laser beam rotates to form a groove in the workpiece 80 with a radius of R1 and substantially the size of the laser beam when it is focused.

Figures 6 and 7 show the focal length of the laser beam being changed to become longer. 6 and 7, the focal length of the laser beam is f2 (f2 > f1), and the focus is formed inside the workpiece 80. Figures 6 and 7 show that when the focal length of the laser beam is retracted and the optical axis moving part 20 is rotated compared to Figure 3, the laser beam rotates to form a groove in the workpiece 80. It was done. The groove is formed continuously to drill the workpiece 80.

The focus of the laser beam in Figure 6 is adjusted to form on the optical axis of the laser beam in Figure 3. The groove formed in FIG. 7 is on an extension of the groove formed in FIG. 5, and since the focal distance is receding, the radius R2 in FIG. 7 is larger than the radius R1 in FIG. 5.

Figures 8 and 9 show drilling performed by changing the focal length of the laser beam to be longer than that in Figure 6. In FIG. 8, the focal length of the laser beam is adjusted to form on the optical axis of the laser beam in FIG. 3, as in FIG. 6.

Specifically, the focus of the laser beam in FIG. 8 recedes back on the optical axis of the laser beam in FIG. 6 and is formed on the bottom of the workpiece 80. In other words, the focal length of the laser beam is given as f3 (f3 > f2). The groove formed in FIG. 9 is on an extension of the groove formed in FIG. 7, and since the focal distance is receding, the radius R3 in FIG. 9 is larger than the radius R2 in FIG. 7.

As a result, a tapered hole is machined in the workpiece 80 through the processes of FIGS. 2, 6, and 8. At this time, each process in FIGS. 2, 6, and 8 is described discontinuously for convenience of explanation, but in reality, drilling of the hole is performed while the focus of the laser beam is continuously retreated. In this way, according to an embodiment of the present invention, the focus of the laser beam is formed while retreating from the optical axis of the laser beam initially irradiated to the surface of the workpiece 80, thereby enabling hole processing in a tapered form. Additionally, the scanner 50 of FIG. 11 may be placed at the front of the first focusing lens 40 to irradiate a laser beam to a desired location on the workpiece 80 to perform drilling.

Figure 10 shows another embodiment of the present invention. This embodiment, like the embodiment according to FIG. 2, includes a variable focus module 10, an optical axis moving unit 20, a first driving unit 30, and a first focusing lens 40. Since the configuration of the variable focus module 10, the optical axis moving unit 20, and the first driving unit 30 is the same as that of the above-described embodiment, detailed description thereof will be omitted.

However, this embodiment is different in that a telecentric lens is used as the first focusing lens 40. The telecentric lens allows the laser beam to be irradiated perpendicularly to the workpiece 80 regardless of the position of the incident laser beam.

As shown in Figure 10, when the laser beam that has passed through the optical axis moving unit 20 is incident on the telecentric lens, the laser that has passed through the telecentric lens is regardless of the angle at which the laser beam is incident. The beam is irradiated vertically to the workpiece 80. Since the telecentric lens itself has a known configuration, its detailed description will be omitted.

In this embodiment, by using a telecentric lens as the first focusing lens 40, the diameter of the hole formed in the workpiece 80 can be enlarged, and by using the telecentric lens, the workpiece (80) can be enlarged. Holes with the same diameter on the front 81 and the rear 82 of 80 can be easily processed.

According to another embodiment of the present invention, like the embodiment according to Figure 2, it includes a variable focus module 10, an optical axis moving unit 20, a first driving unit 30, and a first focusing lens 40. , a scanner 50 that changes the direction of the laser beam irradiated to the surface of the workpiece 80 may be provided between the optical axis moving unit 20 and the first focusing lens 40. In this embodiment, the configuration of the variable focus module 10, the optical axis moving unit 20, the first driving unit 30, and the first focusing lens 40 is the same as that of the above-described embodiment, so the specific The explanation is omitted.

The scanner 50 operates to radiate a laser beam continuously or intermittently to a desired location along a predetermined path across the entire surface of the predetermined workpiece 80.

As shown in Figure 11, the scanner 50 may include a first mirror module 51 and a second mirror module 52. The first and second mirror modules 51 and 52 may be so-called X-Y scanner devices.

Figure 11 shows the first and second mirror modules 51 and 52 according to this embodiment. The first mirror module 51 may include a first mirror 511 that reflects a laser beam, and a first motor 512 that rotates the first mirror 511. In addition, the second mirror module 52, like the first mirror module 51, includes a second mirror 521 that reflects the laser beam, and a second motor that rotates the second mirror 521 ( 522).

In this way, the rotation of the first mirror 511 and the second mirror 521 constituting the scanner 50 are combined to allow the laser beam to be irradiated to a desired location. Since the operation of the scanner device using the mirror and motor may be based on prior art, detailed description will be omitted.

The scanner 50 can be applied to the embodiment of FIG. 10. The scanner 50 can be used to move the laser beam to the edge of the telecentric lens. In this case, the telecentric lens can use the entire lens surface, securing a large processing area on the workpiece 80. It can provide possible effects.

Figure 12 shows another embodiment of the present invention. This embodiment can be implemented by changing the embodiment in which the scanner 50 is applied in FIG. 10. Specifically, this embodiment includes a variable focus module 10, an optical axis moving unit 20, a first driving unit 30, a telecentric lens, and a scanner 50, and in addition, a second focusing lens 90 ) and a second driving unit 60. Since the configuration of the variable focus module 10, the optical axis moving unit 20, the first driving unit 30, the telecentric lens, and the scanner 50 are the same as those of the above-described embodiment, detailed description thereof will be omitted.

As shown in FIG. 12, the second focusing lens 90 is provided between the telecentric lens and the workpiece 80. The second focusing lens 90 shortens the focal length of the laser beam passing through the telecentric lens. Referring to Figure 10, the focal length of the laser beam passing through the telecentric lens is f4, but the focal length of the laser beam is shortened to f5 due to the placement of the second focusing lens 90. In other words, the relationship f4 > f5 is established.

Therefore, the focal length of the laser beam is made shorter than when using only the telecentric lens, thereby securing a large angle of the laser beam incident on the surface of the workpiece 80, thereby creating a tapered shape with a larger inclination (extending the outer wall of the hole). This provides the effect of facilitating hole processing (securing a larger virtual vertex angle). In addition, it provides the effect of reducing the size of the equipment and allowing it to be configured compactly.

The second driving unit 60 is provided to move the second focusing lens 90 so as to move the second focusing lens 90 in conjunction with the direction in which the scanner 50 irradiates the laser beam. do. That is, the second driving unit 60 moves the second focusing lens 90 along the direction in which the laser beam is irradiated by the scanner 50. The second driving unit 60 moves the second focusing lens 90 according to the direction of the laser beam by the scanner 50, so that the workpiece 80 can be easily selected without the need to move it using a separate stage. It provides the effect of quickly processing holes by irradiating a laser beam to a specific location.

According to this embodiment, while the second focusing lens 90 is moved, holes can be machined at a plurality of positions on the workpiece 80. Referring to FIG. 12, the optical axis moving unit 20 rotates the optical axis of the laser beam, and the scanner 50 allows the laser beam to pass through the position of the second focusing lens 90 shown in FIG. 12. Then, the optical axis (VA) of the laser beam that has passed through the second focusing lens 90 rotates to machine a hole in the workpiece 80. At this time, by gradually increasing the focal length of the laser beam that has passed through the second focusing lens 90 by the variable focus module 10, a tapered hole is formed through a process similar to Figures 2, 6, and 8. Process.

When the scanner 50 wants to process a hole by radiating a laser beam to a different position of the workpiece 80, the second driving unit 60 corresponds to the position at which the scanner 50 is set to irradiate the laser beam. Move the second focusing lens 90 to the position. The subsequent hole processing is the same as described above, and through this process, holes can be quickly processed in multiple locations.

In the embodiment according to Figure 12, the control unit 70 controls the focal length of the laser beam by the variable focus module 10 and controls the operation of the scanner 50 to irradiate the laser beam to a set position. do. Additionally, the control unit 70 controls the operations of the first driving unit 30, which rotates the optical axis moving unit 20, and the second driving unit 60, which moves the second focusing lens 90. Since the control unit 70 can be implemented to control the operations of the variable focus module 10, the scanner 50, and the first and second driving units, techniques in the general control field can be applied, and detailed description thereof will be omitted.

In this way, the laser drilling device according to an embodiment of the present invention changes the position irradiated on the surface of the workpiece 80 by moving the optical axis of the incident laser beam, and rotates the optical axis moving unit 20 to change the optical axis of the laser beam. It provides the action or effect of quickly machining holes by rotating it.

Above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications may be made without departing from the scope of the present invention. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the appended claims.

10... Variable focus module 20... Optical axis moving part
21... first prism 22... second prism
30... first driving unit 40... first focusing lens
50... scanner 51... first mirror module
52... 2nd mirror module 511... 1st mirror
512... first motor 521... second mirror
522... second motor 60... second driving unit
70... Control unit 80... Workpiece
81... front 82... rear
90... Second focusing lens

Claims (1)

A variable focus module including a plurality of lenses each having a variable distance between them;
an optical axis moving unit that moves with respect to a reference optical axis when the laser beam passing through the variable focus module is incident, emits the laser beam, and is controlled to perform angular movement; and
It includes a first focusing lens that refracts and focuses the laser beam that has passed through the optical axis moving unit,
The optical axis moving unit is controlled to rotate around a rotation axis parallel to the reference optical axis while drilling is performed through the laser beam that has passed through the first focusing lens,
The optical axis moving unit includes a plurality of prisms spaced apart from each other,
The plurality of prisms of the optical axis moving unit are arranged to rotate around a rotation axis parallel to the reference optical axis through the driving unit,
Drilling a circular hole in a workpiece based on a central axis parallel to the rotation axis through the laser beam that has passed through the variable focus module, the optical axis moving unit, and the first focusing lens,
It further includes a second focusing lens disposed between the first focusing lens and the workpiece to be spaced apart from the first focusing lens and the workpiece to control the focal length of the laser beam passing through the first focusing lens. ,
A laser drilling device comprising moving the second focusing lens in conjunction with a second driving unit along a direction in which the laser beam is irradiated.