TW201805098A - Laser scribing apparatus - Google Patents

Abstract

The present invention relates to a laser scribing apparatus capable of easily changing a focal length of a laser beam when using the laser beam to cut a brittle material substrate. The present invention provides a laser scribing apparatus for performing scribing on a substrate by emitting a laser beam to the substrate, the laser scribing apparatus including: a laser source which generates the laser beam; and a laser emitting unit which receives the laser beam from the laser source and emits the laser beam to the substrate, in which the laser emitting unit includes an optical element that changes a focal length of the laser beam emitted to the substrate.

Description

Laser scoring device

The invention relates to a laser scribing device. More specifically, the present invention relates to a laser scoring device capable of easily changing the focal length of a laser beam when cutting a brittle material substrate using the laser beam.

In some cases, by using a method of cutting an object, a laser beam is used to accurately cut the object to be cut. This method of cutting objects by using a laser beam is also used to cut brittle materials, such as plates made of glass and metal materials.

As one example, a panel for a flat panel display such as a liquid crystal display device is cut by using a laser beam. In the related art, a scribe device for cutting a liquid crystal display device cuts a substrate by a process in which a scribe wheel made of diamond or hard metal is pressed against a surface of a substrate with a predetermined pressure, and then the scribe wheel is rotated and moved To form a scribe line on the surface of the substrate, and perform a chipping process on the substrate.

In contrast, a scoring device using a laser beam forms a crack in the substrate by emitting a laser beam to the substrate and cooling the substrate by using a cooling gas or the like, thereby generating a thermal stress. As an alternative, a method of cutting a substrate by sequentially emitting different laser beams to the substrate has been proposed. Meanwhile, in some cases, after using a laser beam to cut a sealant that joins two substrates constituting a liquid crystal display device or to cut a black matrix formed on a substrate, a scribing wheel is used to Cut the substrate.

However, when the substrate to be cut is uneven or the irradiation depth of the laser beam needs to be adjusted, there is a problem that it is difficult to immediately adjust the irradiation depth of the laser beam.

As an example, published on November 9, 2005, entitled " Apparatus for cutting Nonmetallic Material and Method of Controlling cutting depth When cutting Nonmetallic material ) "Korean Published Patent Application No. 10-2005-0106156 discloses a configuration that measures the distance to a substrate and adjusts the focal length.

However, such a configuration in the related art mechanically controls the height of the emitting device for emitting the laser beam, and has the disadvantage that the response speed is low and it is difficult to increase the substrate cutting speed. If the substrate cutting speed is increased, there is a disadvantage that it is difficult to emit a laser beam to an accurate point (position).

The present invention has been made in an effort to provide a laser scribing device capable of quickly controlling a height by easily changing a focal length of a laser beam.

An exemplary embodiment of the present invention provides a laser scribing device that performs scribing (operation) on a substrate by emitting a laser beam to a substrate. The laser scribing device includes a laser source that generates a laser A light beam; and a laser emission unit that receives a laser beam from a laser source and emits the laser beam to a substrate, wherein the laser emission unit includes an optical element that changes a focal length of the laser beam emitted to the substrate.

In an exemplary embodiment, the laser emitting unit may include: a reflecting mirror that reflects a laser beam propagating from a laser source in a predetermined direction; and a variable-focus mirror that is to be replaced by a reflecting mirror The reflected laser beam is reflected to the substrate, and the focal length is changed by changing the curvature of the reflecting surface; and a condenser lens that collects the laser beam reflected by the variable-angle mirror.

The variable-focus mirror may have a reflecting surface formed of a plurality of micromirrors in the form of an array, and the curvature of the reflecting surface may be changed by changing the positions or angles of the plurality of micromirrors.

The variable focus mirror may include: a pressure chamber into which the fluid is supplied; a reflecting surface that defines one surface of the pressure chamber; and a valve that supplies the fluid into the pressure chamber, and may be Amount or pressure to change the curvature of the reflecting surface.

In an exemplary embodiment, the laser emitting unit may include: a second reflector that reflects the laser beam emitted from the laser source to the substrate; and a zoom lens that is located in the laser reflected by the second mirror The beam path, and change the focus.

The variable focus lens may be made of an electroactive polymer.

According to the present invention, there is an advantage in that the focal length of the laser beam can be controlled quickly according to the distance from the object (object) to be cut or the irradiation depth of the laser beam in the object to be cut.

The advantage of the present invention is that since the focal length of the laser beam can be adjusted without mechanically controlling the height of the laser emitting unit for emitting the laser beam, the responsiveness is high and the object can be cut quickly and accurately.

Therefore, the present invention is advantageous in that by changing the focal length of the laser beam according to the distance from the workpiece, it is possible to form a score line having a uniform depth in a workpiece such as a substrate.

The summary above is exemplary only, and is not intended to be limiting in any way. In addition to the exemplary schemes, embodiments, and features described above, other schemes, embodiments, and features of the invention will be readily appreciated by reference to the drawings and the following detailed description.

1‧‧‧Workbench

3‧‧‧ substrate

10‧‧‧Laser Launch Unit

12‧‧‧Mirror

14‧‧‧ variable mirror

16‧‧‧ condenser lens

18‧‧‧ Distance measuring device

19‧‧‧ measuring unit

20‧‧‧Laser source

22‧‧‧ base board

24‧‧‧Micromirror

26‧‧‧Pressure chamber

28‧‧‧Reflective surface

30‧‧‧ Valve

40‧‧‧Second Mirror

42‧‧‧ Variable Lens

d1, d2‧‧‧ distance

P1, P2‧‧‧Position

FIG. 1 is a view showing a laser scribing device according to a first exemplary embodiment of the present invention.

FIG. 2 is a view showing one example of a zoomable mirror of the scribe device according to the first exemplary embodiment of the present invention.

FIG. 3 is a view showing another exemplary embodiment of a zoomable mirror of a scoring device according to a first exemplary embodiment of the present invention.

FIG. 4 is a view showing a scribing device according to a second exemplary embodiment of the present invention.

It should be understood that these drawings are not necessarily drawn to scale, which present a somewhat simplified representation of the various features illustrating the basic principles of the invention. The specific design features of the invention disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, should be determined in part by the particular intended application and use environment.

In the figures, reference symbols refer to the same or equivalent parts of the invention in the various figures of the drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, for reference symbols indicating constituent elements in each view, it should be noted that even if the same constituent elements are shown in different drawings, they will be represented by the same reference symbols. Moreover, in the following description of the present invention, if it is considered that a detailed description of well-known configurations or functions contained herein may make the subject matter of the present invention unclear, the description will be omitted. Also, an exemplary embodiment of the present invention will be described below, but the technical spirit of the present invention is not limited to the embodiment, but may be modified by those skilled in the art and implemented in various ways.

FIG. 1 is a view showing a laser scribing device according to a first exemplary embodiment of the present invention.

The laser scoring device according to the first exemplary embodiment of the present invention is characterized by including a variable-focus mirror that changes focus and reflects a laser beam.

Referring to FIG. 1, a substrate 3 is loaded on a stage 1. In the ideal case, the substrate 3 has a uniform and flat surface, but the substrate may actually have a slight height difference. The depth of the emitted laser beam can be changed as required. The present invention enables the laser beam to be accurately emitted to a desired portion by changing the focal length of the laser beam. One substrate 3 is shown in FIG. 1, but the substrate 3 may be a plurality of substrates combined, where the two substrates are bonded together when the present invention is actually implemented. Also, the portion irradiated with the laser beam may be a point on the surface of the substrate or a point in the substrate, or may be a sealant for attaching a bonded substrate in some cases.

The laser scoring device according to this exemplary embodiment of the present invention includes: a laser source 20 that generates a laser beam; and a laser emitting unit 10 that receives the laser beam from the laser source 20 and applies the laser The beam is emitted to the substrate 3.

The laser source 20 may be selected according to need, and various laser sources may be used, such as a CO ₂ laser, a YAG laser, a pulse laser, and a femtosecond laser. If necessary, at least one optical element such as a beam expander and a collimator may be included between the laser source 20 and the laser emitting unit 10 or in the laser emitting unit 10.

The laser emitting unit 10 includes: a reflecting mirror 12 that reflects a laser beam emitted from the laser source 20 in a predetermined direction; and a zoomable reflecting mirror 14 that reflects the laser beam reflected by the reflecting mirror 12 and can change its reflection surface The curvature of the lens; and a condenser lens 16 that focuses the laser beam reflected by the variable-focus mirror 14 to form a focus at a predetermined position.

In this exemplary embodiment of the present invention, the laser emitting unit 10 may have a distance measuring device 18. The distance measurement device 18 may include a measurement unit 19. In this exemplary embodiment, the measurement unit 19 may be configured to measure a distance to the substrate 3 by emitting a laser toward the substrate 3 and then receiving a reflected laser.

The laser emitting unit 10 may be configured to be movable above the substrate 3 relative to the substrate 3, so that, in a state where the laser emitting unit 10 is fixed, the table 1 on which the substrate 3 is loaded can be moved, In a state where the stage 1 on which the substrate 3 is mounted is fixed, the laser emitting unit 10 can be moved, or both the laser emitting unit 10 and the stage 1 can be moved.

In this exemplary embodiment, the distance measuring device 18 may measure the distance to the substrate 3 before the laser emitting unit 10 emits a laser beam. That is, the distance measuring device 18 may be disposed in front of the laser emission unit 10 in the processing direction of the laser emission unit 10.

Referring to FIG. 1, the distance to the substrate 3 measured by the distance measuring device 18 is d1, and the position to be irradiated by the laser beam is P1. The control unit (not shown) of the scoring device according to the present invention changes the curvature of the reflecting surface of the variable-focus mirror 14 so that the laser beam generated by the laser source 20 is emitted to P1.

As shown on the right side of FIG. 1, when the laser beam is to be emitted to the position P2 of the substrate 3, the distance to the substrate 3 is d2. In this case, P2 is located at a higher position than P1, and the focal length of the laser beam at P2 needs to be shorter than that at P1. The control unit of the scoring device makes the curvature of the reflecting surface of the zoom mirror 14 at P2 smaller than the curvature at P1, so that the laser beam reflected by the zoom mirror 14 is emitted to the position P2.

FIG. 2 is a view showing one example of a zoomable mirror of the scribe device according to the first exemplary embodiment of the present invention.

Referring to FIG. 2, the zoom mirror 14 may include a base plate 22 and a plurality of micromirrors 24 provided on the base plate 22. The plurality of micromirrors 24 are arranged in the form of an array, and their angles or positions can be individually controlled. As the positions of the plurality of micromirrors 24 are adjusted, the focal length of the laser beam reflected by the micromirror array can be changed. The micromirror array controlled by the micromirror control system disclosed in Korean Patent No. 10-1208273 can be exemplified as an example of the micromirror array.

FIG. 3 is a view showing another exemplary embodiment of a zoomable mirror of a scoring device according to a first exemplary embodiment of the present invention.

Referring to FIG. 3, the zoom mirror 14 includes: a pressure chamber 26; a concave reflecting surface 28 formed on one side of the pressure chamber 26; and a valve 30 that supplies fluid into the pressure chamber 26. The valve 30 may be connected to a pressure source (not shown). The reflecting surface 28 may be made of a flexible material. The fluid to be supplied into the pressure chamber 26 may be a liquid phase fluid (such as water or oil) or a gas. The curvature of the reflecting surface 28 is controlled based on the amount or pressure of the fluid supplied through the valve 30.

Comparing FIG. 3A with FIG. 3B, the amount or pressure of the fluid supplied to the pressure chamber 26 in FIG. 3A is higher or greater than the amount or pressure of the fluid in FIG. 3B. Therefore, the curvature of the reflecting surface 28 in FIG. 3A is larger than that in FIG. 3B.

FIG. 4 is a view showing a scribing device according to a second exemplary embodiment of the present invention.

The scribing device according to the second exemplary embodiment of the present invention may include a laser emitting unit 10 and a laser source 20, and may further include a distance measuring device 18. The laser emitting unit 10 includes a second reflecting mirror 40 that reflects the laser beam propagated from the laser source 20 downward, and a variable focus lens 42 that is located in the optical path of the second reflecting mirror 40 and changes the focus.

The variable focus lens 42 is configured to be able to change the focus. The invention is characterized by variable The focus lens 42 changes the focus by changing the shape of the lens. In this exemplary embodiment, the variable focus lens 42 may be a variable focus fluid lens configured such that its interior is filled with fluid, and its shape is changed by adjusting the amount of fluid that fills its interior. Alternatively, the variable focus lens 42 may be an electroactive polymer (EAP), the shape of which changes with the voltage applied to the EAP. In this exemplary embodiment, EAP is manufactured by mixing polyvinyl chloride (PVC) and a plasticizer in a gel state. The advantage of using the variable focus lens 42 manufactured by EAP is that the shape can be changed quickly with the applied voltage, and the response speed can be improved.

As mentioned above, these exemplary embodiments have been described and illustrated in the specification and drawings. These exemplary embodiments were chosen and described in order to explain some specific principles of the invention and their practical applications, thereby enabling others skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications. . As apparent from the foregoing description, certain aspects of the present invention are not limited by the specific details set forth herein, and it is foreseen that those skilled in the art will be able to think of other modifications and applications or their equivalents. However, after considering the specification and drawings, those skilled in the art will readily appreciate many changes, modifications, and variations of the invention and other uses and applications. All such changes, modifications, and alterations without departing from the spirit and scope of the invention, as well as other uses and applications, are considered to be covered by the invention, and the invention is limited only by the scope of the accompanying patent applications.

1‧‧‧Workbench

3‧‧‧ substrate

10‧‧‧Laser Launch Unit

12‧‧‧Mirror

14‧‧‧ variable mirror

16‧‧‧ condenser lens

18‧‧‧ Distance measuring device

19‧‧‧ measuring unit

20‧‧‧Laser source

d1, d2‧‧‧ distance

P1, P2‧‧‧Position

Claims (6)

A laser scribing device performs a scribing operation on a substrate by emitting a laser beam to the substrate. The laser scribing device includes a laser source that generates the laser beam and a laser emission. A unit that receives the laser beam from the laser source and emits the laser beam to the substrate, wherein the laser emission unit includes an optical element that can change the laser emitted to the substrate The focal length of the beam. The laser scoring device according to claim 1, wherein the laser emitting unit includes: a reflecting mirror that reflects the laser beam propagating from the laser source in a predetermined direction; and a variable-focus mirror as the optical An element that reflects the laser beam reflected by the mirror to the substrate and changes the focal length by changing the curvature of a reflecting surface; and a condenser lens that focuses the laser beam reflected by the variable mirror . The laser scribing device according to claim 2, wherein the zoom mirror has the reflecting surface, the reflecting surface is formed of a plurality of micromirrors in an array, and the curvature of the reflecting surface is changed by changing the plurality of The position or angle of the micromirror is changed. The laser scoring device according to claim 2, wherein the zoom mirror includes: a pressure chamber into which the fluid is supplied; and the reflecting surface, which is flexible and defines a surface of the pressure chamber; And a valve that supplies the fluid into the pressure chamber, the curvature of the reflecting surface changing according to the amount or pressure of the fluid in the pressure chamber. The laser scoring device according to claim 1, wherein the laser emitting unit includes: A second reflector that reflects the laser beam propagating from the laser source to the substrate; and a variable focus lens as the optical element, which is located in the optical path of the laser beam reflected by the second mirror And change focus. The laser scoring device according to claim 5, wherein the zoom lens is made of an electroactive polymer, and when a voltage is applied to the electroactive polymer, the shape of the electroactive polymer changes to change the focus .