KR101547806B1 - Device for processing brittle substrate using aspherical lens having multi focus - Google Patents

Abstract

The present invention relates to a brittle substrate processing apparatus using a laser with an improved processing speed. A brittle substrate processing apparatus according to the present invention includes a laser generating unit for emitting a laser beam, a reflecting mirror for reflecting the laser beam emitted from the laser generating unit and changing the traveling direction of the emitted laser beam, A beam expander for changing the light beam, and a multi-focal lens unit for irradiating a laser beam passed through the beam expander to a plurality of focal points.

Description

TECHNICAL FIELD [0001] The present invention relates to a brittle substrate processing apparatus using a multi-focal aspherical lens,

The present invention relates to a brittle substrate processing apparatus using an aspheric lens having a multi-focal point, and more particularly, to a brittle substrate processing apparatus for improving a processing speed by simultaneously processing two or more points using a multi-focal point.

2. Description of the Related Art Recently, as the importance of the display industry for displaying various information on the screen has increased, studies on flat panel displays capable of high resolution and portable display have been actively conducted.

Such a flat panel display is generally manufactured in the form of a plurality of matrices on a brittle substrate such as a semiconductor chip such as a large-scale integrated circuit, and is manufactured through a process of cutting the substrate into individual devices or modules.

In this case, scribing, blade dicing, laser cutting, stealth dicing, and the like can be used as a method of cutting and separating a brittle substrate composed of glass, silicon, And Thermal Laser Separation (TLS).

Among them, scribing and blade dicing are mechanical cutting methods, and stealth dicing and TLS methods are laser non-contact cutting methods. When machining using the conventional mechanical cutting method, a large amount of chips and residual stress are left in the workpiece, and there is a possibility that the thin film is severely damaged when a thin film having a thickness of 100 μm or less is processed.

As a noncontact cutting method using a conventional laser, there is a heat transfer based machining method. The laser processing method has a merit that thin thin film can be processed without breakage, but it has a disadvantage that it requires a long processing time.

Another object of the present invention is to provide a brittle substrate processing apparatus capable of simultaneously cutting at least two points in a vertical direction in a laser processing apparatus.

An object of the present invention is to provide a brittle substrate processing apparatus for improving a processing speed in a laser processing apparatus.

An object of the present invention is to provide a brittle substrate processing apparatus using a laser, which is excellent in quality of a cutting surface and has improved mass productivity.

A brittle substrate processing apparatus according to the present invention includes: a laser generation unit for emitting a laser beam; A reflecting mirror for reflecting the emitted laser beam from the laser generating unit and changing a traveling direction of the emitted laser beam; A beam expander for changing the light beam of the laser beam reflected by the reflecting mirror; And a multi-focal lens unit that irradiates the laser beam passed through the beam expander to a plurality of focal points.

In an embodiment, the plurality of focal points are located on the same vertical line.

In an embodiment, the plurality of focal vertical lines are on the optical axis of the laser beam passing through the beam expander.

In an embodiment, the distance between the plurality of focal points is adjustable according to the thickness of the object on which the plurality of focal points are located.

In an embodiment, the plurality of focal points are two different focal points.

In an embodiment, the laser beam is a pulse wave laser beam.

In an embodiment, the laser beam is a continuous wave (CW) laser beam.

In an embodiment, the focus lens unit includes a first lens; And a second lens having a refractive index different from that of the first lens, wherein the second lens includes a plurality of spherical regions divided by a plurality of concentric circles having the same center and different radii, and the plurality of spherical regions Each of which is characterized by including a spherical portion configured to have a different curvature.

In an embodiment, the size of the second lens or the plurality of spherical regions may be adjusted according to the magnification of the second lens or the plurality of spherical regions.

In an embodiment, each of the plurality of spherical regions is configured to have the same horizontal cross-sectional area.

The brittle substrate processing apparatus according to the present invention can simultaneously process at least two points in the vertical direction.

Further, the processing speed in the laser processing method can be remarkably improved.

An object of the present invention is to provide a brittle substrate processing apparatus using a laser, which is excellent in quality of a cutting surface and has improved mass productivity.

1 is a block diagram showing a brittle substrate processing apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram specifically illustrating the multi-focal lens unit of FIG. 1. FIG.
3 is a view for explaining a basic principle for forming a multi-focus using a lens according to the present invention.
4 is a cross-sectional view (a) and a plan view (b) of a multifocal lens of the multifocal lens unit of FIG. 2 according to an embodiment of the present invention.
5 is a plan view specifically showing a method for constructing the multi-focal lens shown in Fig.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

1 is a block diagram showing a brittle substrate processing apparatus according to an embodiment of the present invention. Referring to FIG. 1, a brittle substrate processing apparatus 100 includes a laser generating unit 110, a reflecting mirror 120, a beam expander 130, and a multi-focal lens unit 140.

The laser generating unit 110 functions as a laser light source for generating and emitting a laser beam. The laser beam emitted from the laser generation unit 110 proceeds to the reflection mirror 120. The general construction and principle of the laser generating portion 110 are well known in the art, and a description thereof will be omitted here.

In an embodiment, the laser beam emitted by the laser generating unit 110 may be a pulse wave laser beam or a continuous wave (CW) laser beam.

The reflection mirror 120 reflects the laser beam emitted from the laser generator 110 to change the traveling direction of the laser beam. Here, the reflective mirror 120 is represented as a mirror, but not limited thereto, and any other object or material that can reflect the laser beam and change the traveling direction of the laser beam can be used as the reflective mirror 120.

As an embodiment, the reflection mirror 120 can freely control the traveling direction of the reflected laser beam by adjusting the incident angle and the reflection angle of the laser beam.

As an example, the reflective mirror 120 may be disposed parallel to the laser generator 110.

As an example, the reflective surface of the reflective mirror 120 may be planar.

As an example, the reflection mirror 120 may be configured such that the incident angle and the reflection angle of the incident laser beam are respectively 45 degrees.

The beam expander 130 produces a parallel light beam with the size of the laser beam reflected from the reflective mirror 120. The beam expander 130 converts a small light beam, such as light from a laser, into a thick parallel light beam. The beam expander 130 may be disposed on the traveling line of the laser beam reflected from the reflecting mirror 120.

In an embodiment, the beam expander 130 may be composed of two sets of lenses whose focal positions are matched to change the beam width of the laser beam (or the diameter of the laser beam).

The multi-focus lens unit 140 causes the laser beam passed through the beam expander 130 to be divided into two or more focuses. The multi-focal lens unit 140 allows a laser beam to be divided into two or more focal points located on the same vertical line using a multi-focal lens forming a plurality of focal points. At this time, the brittle substrate processing apparatus 100 can cut or punch the processing point of the object to be processed by matching the focal points irradiated with the laser beam with the processing point of the object.

As an example, the plurality of foci formed by the multi-focal lens unit 140 may be located on the optical axis of the laser beam passing through the beam expander 130.

In an embodiment, the multi-focal lens unit 140 may include a focal length adjusting unit that adjusts a focal distance between a plurality of focal points formed by the multi-focal lens unit 140. The details of the focal length adjusting unit for adjusting the distance between two or more focal points are well known in the art, and a description thereof will be omitted here.

As an example, the multi-focal lens section 140 may include a multi-focal lens (not shown) having a plurality of focal points, wherein the size of the multi-focal lens can be changed according to the magnification of the multi-focal lens

As an embodiment, the multi-focal lens section 140 divides and irradiates a laser beam that has passed through the beam expander 130 to two foci 10 and 20 formed on the optical axis of the laser beam.

The configuration and operation of the multi-focus lens unit 140 will be described later in more detail with reference to FIG.

According to the above configuration, the brittle substrate processing apparatus 100 according to the present invention can irradiate a laser beam toward at least two focal points in the vertical direction. Therefore, the brittle substrate processing apparatus 100 can simultaneously process two or more points, thereby significantly improving the processing speed.

In addition, the brittle substrate processing apparatus 100 according to the present invention cuts the brittle substrate in a non-contact manner using a laser beam, so that the quality and mass productivity of the processed substrate surface can be further improved.

FIG. 2 is a block diagram specifically illustrating the multi-focal lens unit of FIG. 1. FIG. Referring to FIG. 2, the multi-focal lens unit 140 divides an incident laser beam into two focal points 10 and 20. At this time, the sum of the energy of the laser beams divided into the two focal points 10 and 20 is equal to the energy of the laser beam incident on the multi-focal lens unit 140. That is, the multi-focal lens unit 140 disperses the energy of the incident laser beam into two focal regions and irradiates the focal regions.

The two foci 10 and 20 formed by the multi-focal lens unit 140 may be positioned on the same vertical line. For example, the two foci 10, 20 may be located on the optical axis of the incident laser beam.

Two focal points 10 and 20 formed by the multi-focal lens section 140 may be located at the first processing point or the second processing point of the object to be processed. The multi-focus lens unit 140 divides the incident laser beam into two focal points 10 and 20, that is, first and second machining points, so that the first and second machining points of the workpiece are cut or punched .

Two focuses 10 and 20 formed by the multi-focus lens unit 140 can be adjusted according to the machining points of the object to be processed. For example, if the thickness of the object to be processed is large, the distance between the foci 10 and 20 can be adjusted such that the two foci 10 and 20 are farther apart from each other. On the other hand, if the thickness of the object to be processed is thin, the distance between the foci 10 and 20 can be adjusted such that the two foci 10 and 20 are closer to each other.

3 is a view for explaining the basic principle for forming a multi-focal point by using the multi-focal lens according to the present invention. Referring to FIG. 3, (a) shows a conventional focus lens 310 and (b) shows a multi-focal lens 320 according to the present invention.

The conventional focus lens 310 irradiates the incident light (or the laser beam) toward one focal point. Accordingly, the light irradiated through the conventional focus lens 310 is concentrated in a region where the depth of focus (DOF) is relatively shallow and the energy of the irradiated light is narrow.

On the other hand, the focus lens 320 according to the present invention irradiates incident light (or a laser beam) toward a plurality of foci (e.g., two foci). Therefore, the light irradiated through the focus lens 320 of the present invention has a deep depth of focus (DOF), and the energy of the irradiated light is divided into at least two regions.

4 is a cross-sectional view and a plan view showing a multi-focal lens of the multi-focal lens unit of FIG. 2 according to an embodiment of the present invention. Referring to FIG. 4, the multi-focal lens includes a body portion 410 and a spherical portion 420.

Referring to FIG. 6A, the body 410 advances the incident laser beam and transmits the laser beam to the spherical portion 420. The body portion 410 may include two lenses having different refractive indices. The first lens (white box) of the two lenses directs the incident laser beam to the second lens (the hatched box) of the two lenses. At this time, the transmitted laser beam is refracted at the boundary between the first lens and the second lens, and the traveling direction of the laser beam can be changed. The laser beam whose traveling direction is changed proceeds toward the center of the spherical portion 420 and allows the energy of the laser beam to be concentrated in a narrower region in the spherical portion 420.

The spherical portion 420 has a spherical surface configured to form a plurality of foci. The spherical surface of the spherical portion 420 is configured to have a first curvature at the edge, and is configured to have a second curvature at the center. Here, the spherical surface of the spherical portion 420 is represented by two regions having different curvatures, but is not limited thereto. The spherical surface of the spherical portion 420 may have three or more regions having different curvatures, so that three or more spherical portions 420 may form a focal point.

The laser beam reaching the region having the first curvature (hereinafter, referred to as the first spherical region) of the laser beam transmitted to the spherical portion 420 is directed toward the first focal point 10 formed according to the curvature of the first spherical region Refracted and inspected. On the other hand, the laser beam reaching the region having the second curvature (hereinafter referred to as the second spherical region) is refracted and irradiated toward the second focal point 20 formed according to the curvature of the second spherical region.

According to the configuration of the above-described multi-focal lens, the laser beam incident on the multi-focal lens unit 140 (see FIG. 1) is refracted and irradiated by the two focal points 10 and 20.

(b) Referring to the drawing, another embodiment of a multi-focal lens is shown. (a) In the drawing, a multi-focal lens is constituted by a single lens having an aspheric surface, while (b) a multi-focal lens in the drawing combines two lenses having different spherical surfaces to form spherical surfaces Resulting in an aspherical surface). At this time, the two lenses constituting the spherical portion may correspond to the first spherical region and the second spherical region in (a), respectively.

(b) In the embodiment shown in the drawings, the two lenses constituting the multi-focal lens can be respectively constituted and arranged in the form of a concentric circle having the same center and different radii.

5 is a plan view specifically showing a method for constructing the multi-focal lens shown in Fig. Referring to FIG. 5, the spherical portion of the multi-focal lens has two spherical regions divided into two concentric circles having the same center and different radii.

In this embodiment, the two spherical areas of the multi-focal lens can be configured to have the same horizontal cross-sectional area when looked down from the plane. For example, the area of the horizontal section 510 of the first spherical region and the area of the horizontal section 520 of the second spherical region (i.e., the area obtained by subtracting the area of the outer concentric circle from the area of the inner concentric circle) .

That is, by making the areas of the horizontal sections of the first and second spherical regions equal to each other, the energy of the laser beam irradiated to the first focus 10 (see FIG. 1) and the second focus 20 The same can be achieved.

For example, the radius of the inner concentric circle forming the first spherical region is 5.3025 cm, and the radius of the outer concentric circle forming the second spherical region is 7.5 cm. Here, the areas of the end face 510 of the first spherical region and the end face 520 of the second spherical region are expressed by Equations (1) and (2), respectively.

According to Equations (1) and (2), it can be seen that the areas of the end face 510 of the first spherical region and the end face 520 of the second spherical region are equal to each other.

As an example, the area of the first and second spherical regions may be changed according to the size of the lens or the like.

As an embodiment, the ratio of the horizontal cross-sectional area of the first and second spherical regions may be different in order to make the ratio of the laser beam energy irradiated to the first and second focal points 10 and 20 different. For example, in order to focus more laser beam energy on the second focal spot 20 than the first focal spot 10, the horizontal cross-sectional area 510 of the first spherical area and the horizontal monotonic 520 of the second spherical surface Width ratio can be adjusted to be 1: 2.

According to the above configuration, the brittle substrate processing apparatus 100 according to the present invention can irradiate a laser beam toward at least two focal points in the vertical direction. Therefore, the brittle substrate processing apparatus 100 can simultaneously process two or more points, thereby significantly improving the processing speed.

Further, the brittle substrate processing apparatus 100 according to the present invention cuts the brittle substrate in a non-contact manner using a laser beam, so that the quality and mass productivity of the processed substrate surface can be further improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

In addition, although specific terms are used herein, they are used for the purpose of describing the present invention only and are not used to limit the scope of the present invention described in the claims or the claims. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by the claims equivalent to the claims of the present invention as well as the claims of the following.

100: brittle substrate processing device
110: laser generator
120: Reflective mirror
130: beam expander
140: Multi-focus lens unit
10, 20: Focuses
310, 320: Focus lens
410: body portion of a multi-focal lens
420: spherical portion of the multi-focal lens
510: a first spherical area of the multi-focal lens
520: second spherical area of the multi-focal lens

Claims (10)

A laser generator for emitting a laser beam;
A reflecting mirror for reflecting the emitted laser beam from the laser generating unit and changing a traveling direction of the emitted laser beam;
A beam expander for changing the light beam of the laser beam reflected by the reflecting mirror; And
And a multi-focal lens unit for dividing the laser beam passed through the beam expander into a plurality of focal points including two different focal points,
Wherein the beam expander is positioned between the reflective mirror and the multi-focal lens unit,
Wherein the multi-focal lens unit includes a body portion including two or more lenses having different refractive indices, and a spherical portion having a plurality of spherical regions divided by a plurality of concentric circles having the same center and different radii, Are each configured to have different curvatures,
Adjusting a width ratio of a horizontal cross-sectional area of the plurality of spherical areas to different ratios of the laser beam energy irradiated to the plurality of focal points,
Adjusting the width ratios of the horizontal cross-sectional areas of the plurality of spherical areas to be equal to each other to make the energy of the laser beams irradiated to the plurality of focal points equal to each other,
Wherein the beam expander is disposed on a traveling line of the laser beam reflected from the reflecting mirror and converts the light beam of the reflected laser beam into a thick parallel light beam,
Wherein the laser beam that has passed through the beam expander is refracted at the boundary between the two or more lenses of the body and concentrated at the center of the spherical portion.
The method according to claim 1,
Wherein the plurality of focal points are located on the same vertical line.
3. The method of claim 2,
Wherein the plurality of focal vertical lines are on the optical axis line of the laser beam passing through the beam expander.
The method of claim 3,
Wherein the distance between the plurality of focal points is adjustable according to the thickness of the object to which the plurality of focal points are located.
delete The method according to claim 1,
Wherein the laser beam is a pulse wave or a continuous wave (CW) laser beam. delete delete delete delete

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