KR20200094335A - Apparatus for drilling hole using laser - Google Patents

Abstract

According to one embodiment of the present invention, provided is a laser hole processing apparatus capable of processing a hole of a high-aspect ratio by using a laser beam, and controlling the diameter of the processed hole in real time. Here, the laser hole processing apparatus, which is a laser hole processing apparatus for processing a hole on a substrate by radiating a laser beam, includes a first lens, a condensing lens, a second lens and a first driving part. The first lens has a concave exit plane, forms a laser beam emitted from the exit plane such that the beam has a ring-shaped cross section shape and makes the diameter of the laser beam get larger as the laser beam gets farther from the exit plane. The second lens has a convex incidence plane and is provided between the condensing lens and the focus position, and enables the laser beam to have a beam path having an increasing diameter and form a ring-shaped cross section shape by changing a path such that the laser beam emitted from the condensing lens intersects more ahead than the focus position. The first driving part enables the diameter of the ring-shaped cross section shape of the laser beam to be periodically changed on the focus position by reciprocating the second lens in a direction getting closer to or farther from the condensing lens.

Description

Laser hole processing equipment {APPARATUS FOR DRILLING HOLE USING LASER}

The present invention relates to a laser hole processing apparatus, and more specifically, a laser hole processing apparatus capable of processing a high aspect ratio hole using a laser beam and controlling the size of the diameter of the processed hole in real time. It is about.

In general, a method of forming a hole in a material includes mechanical drilling, dry or wet etching, and laser drilling. Among them, the laser perforation method has an advantage of less dust generation and a smoother cutting surface than the mechanical perforation method, and has a short process time as well as a simple process device, etc., compared to the etching method.

Accordingly, in recent years, in fields where precision processing is required, such as semiconductors and displays, there are increasing cases of using laser processing devices when forming or cutting holes in materials such as silicon, glass, and ceramics.

The laser processing device processes the material by focusing the laser beam emitted from the laser light source to the material through a focusing lens.

1 to 3 is an exemplary view showing a conventional laser drilling method.

First, as shown in (a) and (b) of FIG. 1, when the diameter D1 of the hole 11 to be formed in the substrate 10 is larger than the focal diameter D2 of the laser beam 20, The laser beam 20 is processed by reciprocating in the radial direction of the hole 11. However, since the diameter of the laser beam 20 increases toward the upper side of the focus, the energy loss of the laser beam 20 is generated as the laser beam 200 continuously contacts the edge surface 12 of the hole 11. Can. And as a result of this energy loss, as shown in Figure 1 (c), the hole 11 is formed to be tapered (13). Accordingly, a diameter D3 smaller than the desired diameter D1 is formed at the lower end of the hole 11, and there is a problem that a hole with a high aspect ratio cannot be obtained.

As a method for overcoming this, a trepanning processing optical system as shown in FIG. 2(a) was introduced.

The traning process optical system is provided with a plurality of wedges 31 and 32 to periodically change the path of the laser beam 20 so that the laser beam 20 is incident on the hole 11 in an outward direction, thereby making the substrate 10 ) To process the hole (11).

However, this processing method requires a rotational configuration for rotating the wedges 31 and 32, and is affected by vibrations generated due to the structural characteristics of the rotational configuration. As a result, as shown in (b) of FIG. 2, even if the hole 11 is formed in a garden, the edge surface of the hole 11 has an irregular shape, or, in FIG. As shown in ), there is a problem in that the hole 11 has an elliptical shape and the processing quality is deteriorated.

On the other hand, as shown in Figure 3, in the conventional laser drilling method, when processing a plurality of holes having different diameters, there is a hassle of resetting the equipment to match the diameter of the holes.

That is, in the case of processing holes 11a having different diameters on the substrate 10, the conventional laser drilling method has a problem in that it is difficult to process these holes in one continuous process.

Republic of Korea Patent Publication No. 2018-0108086 (released on October 4, 2018)

In order to solve the above problems, the technical problem to be achieved by the present invention is a laser hole that can process a high aspect ratio hole using a laser beam and control the diameter size of the hole to be processed in real time. It is to provide a processing device.

The technical problem to be achieved by the present invention is not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the following description. There will be.

In order to achieve the above technical problem, an embodiment of the present invention is a laser hole processing apparatus for processing a hole in a substrate by irradiating a laser beam, having a concave emission plane, and a laser beam emitted from the emission plane is in the form of a ring A first lens formed to have a cross-sectional shape of and to increase in diameter as it moves away from the exit plane; A condensing lens that causes the laser beam incident after being emitted from the first lens to be focused at a focal position formed on the substrate; A beam path having a convex incidence plane and provided between the condenser lens and the focal position, and modifying a path so that the laser beam emitted from the condenser lens intersects in front of the focal position, thereby increasing the diameter of the laser beam. A second lens having a ring-shaped cross-sectional shape; And a first driving unit that reciprocally moves the second lens in a direction closer to or away from the condensing lens to periodically change the cross-sectional shape diameter of the ring shape at the focal position. A hole processing device is provided.

In an embodiment of the present invention, the first driving unit is continuous between the first diameter corresponding to the diameter of the hole in the cross-sectional shape of the ring shape at the focal position, and the second diameter smaller than the first diameter. The substrate can be surface-machined by repeating the increase and decrease.

In an embodiment of the present invention, further comprising an output control unit for controlling the output of the laser beam incident on the first lens, the output control unit is closer to the distance between the condensing lens and the second lens, the focus position The larger the diameter of the cross-sectional shape of the ring shape, the larger the output of the laser beam, and the distance between the condensing lens and the second lens increases, and the smaller the diameter of the cross-sectional shape of the ring shape at the focal position. It is possible to make the energy density of the laser beam constant at the focal position by reducing the output of the laser beam.

In an embodiment of the present invention, the first lens is provided so that the distance from the condensing lens is variable, and the closer the distance between the first lens and the condensing lens is, the laser beam emitted from the second lens The convergence angle of becomes smaller, and as the distance between the first lens and the condensing lens increases, the convergence angle of the laser beam emitted from the second lens may increase.

According to the embodiment of the present invention, since the laser beam irradiated to the substrate has a ring-shaped cross-sectional shape, the hole formed in the substrate may have a high aspect ratio.

In addition, according to an embodiment of the present invention, since the laser beam irradiated to the substrate has a shape in which the diameter of the cross-sectional shape of the ring shape is increased, the laser beam is formed only at the corner portion of the bottom surface of the hole as in the prior art when machining holes. To reach. Therefore, it is possible to reduce the energy loss of the laser beam at the edge surface of the hole, to make the edge surface of the hole clean, and to process a high aspect ratio hole.

In addition, according to an embodiment of the present invention, since the laser beam irradiated on the substrate can be continuously irradiated and the diameter of the laser beam can be changed at the same time, holes in which different diameters are stepped are processed by one continuous process. can do.

Further, according to an embodiment of the present invention, the convergence angle of the laser beam emitted from the second lens may be adjusted by adjusting the distance between the first lens and the condensing lens. By using this, when the thickness of the substrate is thick, the convergence angle of the laser beam emitted from the second lens is reduced, so that the laser beam between the second lens and the crossing position is not interfered by the edge of the hole and energy loss does not occur. have.

In addition, according to an embodiment of the present invention, the output control unit increases the output of the laser beam as the diameter of the cross-sectional shape of the ring shape of the laser beam increases at the focus position, and the diameter of the cross-sectional shape of the ring shape of the laser beam at the focus position The smaller the output, the smaller the output power of the laser beam. Through this, even if the diameter of the laser beam is different at the focal position, the energy density of the laser beam may be constant.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 to 3 is an exemplary view showing a conventional laser drilling method.
4 is an exemplary view schematically showing a laser hole processing apparatus according to an embodiment of the present invention.
5 is an exemplary view showing a cross-sectional shape of the laser beam in the focal point of FIG. 4.
6 is an exemplary view showing an operation example of the laser hole processing apparatus of FIG. 4.
7 is an exemplary view showing a hole processing example using the laser hole processing apparatus of FIG. 4.
8 is an exemplary view showing another operation example of the laser hole processing apparatus of FIG. 4.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and thus is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part is “connected (connected, contacted, coupled)” with another part, it is not only “directly connected”, but also “indirectly connected” with another member in between. ”Also includes the case. Also, when a part “includes” a certain component, this means that other components may be further provided instead of excluding other components, unless otherwise stated.

The terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms “include” or “have” are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 is an exemplary view schematically showing a laser hole processing apparatus according to an embodiment of the present invention, Figure 5 is an exemplary view showing a cross-sectional shape of the laser beam of Figure 4, Figure 5 (a) of Figure 4 The cross-sectional shape of the A-A' line is shown, and FIG. 5(b) shows the cross-sectional shape of the B-B' line of FIG. 4.

4 and 5, the laser hole processing apparatus according to the present invention may have a first lens 100, a condensing lens 200, a second lens 300 and a first driving unit 400.

The first lens 100 may have a concave emission plane 110. The first lens 100 may be formed such that the laser beam 20 emitted from the emission plane 110 has a ring-shaped cross-sectional shape. That is, even if the laser beam 20 incident on the first lens 100 has a solid cross-sectional shape (see FIG. 5(a) ), the exit plane of the first lens 100 The laser beam 20 emitted from 110 may have a ring-shaped cross-sectional shape (see FIG. 5(b) ).

In addition, the first lens 100 may allow the diameter of the laser beam 20 emitted from the exit plane 110 to increase as the distance from the exit plane 110 increases.

The condenser lens 200 may allow the laser beam 20 incident after being emitted from the first lens 100 to be focused at the focal position P1. That is, the focal position P1 of the laser beam 20 emitted from the first lens 100 may be determined by the condensing lens 200.

The second lens 300 may be provided between the condensing lens 200 and the focal position P1, and may have a convex incident plane 310.

The second lens 300 may modify the path of the laser beam 20 such that the laser beam 20 emitted from the condensing lens 200 intersects in front of the focal position P1. That is, the laser beam 20 whose path is modified by the second lens 300 may be provided with an intersecting position P2 intersecting each other in front of the focal position P1. Thereafter, the diameter of the laser beam 20 increases as the distance from the crossing position P2 increases, and focus may be formed at the focus position P1. Therefore, the laser beam 20 may have a ring-shaped cross-sectional shape even at the focal position P1.

The first lens 100 and the second lens 300 may be Axicon lenses.

Since the condensing lens 200 converges the laser beam 20 emitted from the first lens 100 to focus at the focal position P1, the laser beam 20 is not provided without the second lens 300. It can have a beam path with decreasing diameter. However, the second lens 300 makes the convergence angle of the laser beam 20 smaller than the convergence angle at which the laser beam 20 converges by the condensing lens 200, so that the laser in front of the focal position P1 The beam 20 can be crossed, and thus, the laser beam 20 passing through the crossing position P2 may have a beam path with an increased diameter.

The first driving unit 400 may reciprocate the second lens 300 in a direction closer to or away from the condensing lens 200. The first driving part 400 may allow the second lens 300 to periodically reciprocate, and through this, the diameter of the ring-shaped cross-sectional shape of the laser beam 20 at the focal position P1 is also periodically changed. can do.

The first driving unit 400 may include a piezo optical element or a piezo actuator.

6 is an exemplary view showing an operation example of the laser hole processing apparatus of FIG. 4. Hereinafter, it will be further described with reference to FIG. 6.

6, the second lens 300 is moved by the first driving unit 400, the closer the distance between the condensing lens 200 and the second lens 300 is, the second lens The intersection position P2 at which the laser beam 20 emitted from the 300 intersects may be distant from the focal position P1. That is, the closer the distance between the condenser lens 200 and the second lens 300 is, the more the crossing position P2 can be moved forward. And, the diameter of the cross-sectional shape of the ring shape of the laser beam 20 at the focal position P1 may be gradually increased.

That is, in the state where the laser beam 20 is formed with the first diameter D4 at the focal position P1 as shown in FIG. 6A, the second lens 300 as shown in FIG. 6B. When moving further away from the condenser lens 200, the crossing position P2 is further moved in the direction of the focal position P1. Then, the diameter of the laser beam 20 at the focal position P1 is further reduced from the first diameter D4 to the second diameter D4'. Then, when the second lens 300 is moved closer to the condenser lens 200, the cross position P2 is moved toward the condenser lens 200, and the diameter of the laser beam 20 at the focal position P1 is It increases from the second diameter (D4') to the first diameter (D4).

As such, the first driving unit 400 moves the second lens 300 to adjust the distance between the condensing lens 200 and the second lens 300, and through this, the focal position P1 according to the diameter of the hole to be processed. In the diameter of the cross-sectional shape of the ring shape of the laser beam 20 can be easily adjusted. Therefore, there is an advantage that additional configuration of a separate optical system for adjusting the diameter of the laser beam or replacement of the optical system is unnecessary.

7 is an exemplary view showing a hole processing example using the laser hole processing apparatus of FIG. 4.

Referring to further including FIG. 7, the first driving unit 400 has a first diameter (D4) in which the diameter of the ring-shaped cross-sectional shape of the laser beam 20 at the focal position P1 corresponds to the diameter of the hole 11. ) And the second diameter D4' smaller than the first diameter D4 may be repeated continuously.

Since the laser beam at the focal position P1 has a ring-shaped cross-sectional shape, the focal position P1 is applied to the substrate 10 so that the diameter is repeated with the first diameter D4 and the second diameter D4'. When the laser beams 20 and 20' are irradiated, a portion where the laser beams 20 and 20' are irradiated is surface-processed, and a hole having a first diameter D4 may be formed.

According to this embodiment, the laser beam 20 irradiated to the substrate 10 from the beginning has a ring-shaped cross-sectional shape, and is irradiated while the diameter is periodically varied to process the hole 11 in the substrate 10. have.

In addition, when referring to FIG. 7, the laser beam 20 irradiated with the first diameter D4 forms a shape in which the diameter of the cross-sectional shape of the ring shape is enlarged. ) Does not touch the edge of the hole. Therefore, the energy loss of the laser beam can be reduced at the edge surface 12 of the hole 11, the edge surface 12 of the hole 11 has a clean shape, and a high aspect ratio hole can be processed.

In addition, since the diameter of the cross-sectional shape of the ring shape of the laser beam can be changed while allowing the laser beam irradiated to the substrate 10 to be continuously irradiated, different diameters are stepped as shown in FIG. 3. Holes can also be processed in one continuous process.

Meanwhile, in FIG. 7, the laser beam 20 ′ is illustrated to have a second diameter D4 ′, but this is for illustration purposes, and the laser beam 20 ′ may be focused to a point. Alternatively, the second diameter D4' of the laser beam 20' may be larger than that shown. In this case, the substrate of the inner portion of the second diameter D4' may not be processed by the laser beam 20', but as a result, the unprocessed portion is finally separated from the hole 11 as a result. Can obtain a hole 11 of the form shown in Figure 7 (c).

Referring to FIG. 4 again, the laser hole processing apparatus may further include an output control unit 500.

The output control unit 500 may control the output of the laser beam 20 irradiated from the irradiation unit 90 and incident on the first lens 100.

The output control unit 500 is closer to the distance between the condenser lens 200 and the second lens 300, the larger the diameter of the cross-sectional shape of the ring shape of the laser beam 20 at the focal position P1, the larger the laser beam 20 becomes. Can increase the output of In addition, the output control unit 500 increases the distance between the condenser lens 200 and the second lens 300, the smaller the diameter of the cross-sectional shape of the ring shape of the laser beam at the focal point P1 is, the smaller the diameter of the laser beam is. It can be made small.

Through this, even if the diameter of the laser beam is different at the focal position P1, the energy density of the laser beam may be constant.

8 is an exemplary view showing another operation example of the laser hole processing apparatus of FIG. 4.

As shown in FIG. 8, in the laser hole processing apparatus according to the present invention, the first lens 100 may be provided to have a variable distance from the condensing lens 200.

As the distance between the first lens 100 and the condensing lens 200 increases, the convergence angle at which the laser beam 20 emitted from the second lens 300 converges may increase.

That is, when the distance between the condenser lens 200 and the second lens 300 is constant, the focal position P1 and the crossing position P2 may be constant. However, when the distance between the first lens 100 and the condensing lens 200 increases, the diameter when the laser beam 20 emitted from the first lens 100 enters the condensing lens 200 increases. do. Therefore, the convergence angle of the laser beam 20 emitted from the condensing lens 200 becomes large. However, since the second lens 300 needs to make the laser beam 20 emitted from the condensing lens 200 intersect at the crossing position P2, the second lens 300 has a laser beam 20 emitted from the second lens 300. The convergence angle becomes larger.

Accordingly, when the first lens 100 moves from the state shown in FIG. 8(a) to the state shown in FIG. 8(b) and the first lens 100 moves away from the condensing lens 200, the second lens The convergence angle emitted from 300 is increased from the first convergence angle CA1 to the second convergence angle CA2.

Reducing the convergence angle of the laser beam 20 emitted from the second lens 300 may be implemented by making the distance between the first lens 100 and the condensing lens 200 closer.

As such, the present invention can adjust the convergence angle of the laser beam 20 emitted from the second lens 300 by adjusting the distance between the first lens 100 and the condensing lens 200. When the thickness of the substrate is so thick that the cross position (P2) must be located inside the substrate in the process of hole processing on the substrate, the laser beam (20) between the second lens (300) and the cross position (P2) is the hole It can be interfered by the edge surface. In this case, the convergence angle of the laser beam 20 emitted from the second lens 300 is reduced so that the substrate is not processed by the laser beam 20 between the second lens 300 and the crossing position P2. Through this, it is possible to prevent the energy loss of the laser beam (20).

In addition, since the present invention can easily adjust the convergence angle of the laser beam 20 irradiated from the second lens 300 by adjusting the distance between the first lens 100 and the condensing lens 200, the laser beam There is an advantage that additional configuration of a separate optical system for adjusting the convergence angle of or the replacement of the optical system is unnecessary.

The above description of the present invention is for illustration only, and those skilled in the art to which the present invention pertains can understand that the present invention can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all modifications or variations derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

10: substrate 11: hole
12: edge surface 20,20': laser beam
100: first lens 110: exit plane
200: condensing lens 300: second lens
310: incident plane 400: first driving unit
500: output control unit

Claims (4)

As a laser hole processing device for processing a hole in a substrate by irradiating a laser beam,
A first lens having a concave emission plane, shaping the laser beam emitted from the emission plane to have a ring-shaped cross-sectional shape, and increasing the diameter as it moves away from the emission plane;
A condensing lens that causes the laser beam incident after being emitted from the first lens to be focused at a focal position formed on the substrate;
A beam path having a convex incidence plane and provided between the condenser lens and the focal position, and modifying a path so that the laser beam emitted from the condenser lens intersects in front of the focal position, thereby increasing the diameter of the laser beam. A second lens having a ring-shaped cross-sectional shape; And
And a first driving unit for reciprocating the second lens in a direction closer to or away from the condensing lens to periodically change the cross-sectional shape diameter of the ring shape at the focal position. Processing equipment. According to claim 1,
The first driving unit repeats a continuous increase/decrease between the first diameter corresponding to the diameter of the hole and the second diameter smaller than the first diameter at the focal position so as to repeat the increase and decrease of the substrate. A laser hole processing apparatus characterized in that this surface is processed. According to claim 1,
Further comprising an output control unit for controlling the output of the laser beam incident on the first lens,
The output control unit
The closer the distance between the condensing lens and the second lens is, the larger the diameter of the cross-sectional shape of the ring at the focal position is, the larger the output of the laser beam is,
As the distance between the condenser lens and the second lens increases, the smaller the diameter of the cross-sectional shape of the ring shape at the focal position, the smaller the output of the laser beam and the energy density of the laser beam at the focal position is constant. Laser hole processing apparatus characterized in that to make. According to claim 1,
The first lens is provided so that the distance from the condensing lens is variable,
The closer the distance between the first lens and the condensing lens is, the smaller the convergence angle of the laser beam emitted from the second lens is,
The longer the distance between the first lens and the condensing lens, the laser hole processing apparatus characterized in that the convergence angle of the laser beam emitted from the second lens increases.

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