KR101650076B1

KR101650076B1 - Machining method of substrate of fragile material

Info

Publication number: KR101650076B1
Application number: KR1020140069907A
Authority: KR
Inventors: 최동광
Original assignee: 한국미쯔보시다이아몬드공업(주)
Priority date: 2014-06-10
Filing date: 2014-06-10
Publication date: 2016-08-22
Also published as: TWI658016B; CN105312775B; JP2015231739A; CN105312775A; TW201546004A; KR20150141342A

Abstract

The present invention provides a method of manufacturing a brittle material substrate, the method comprising: laser processing a front surface of a substrate to a predetermined depth along a guide line spaced apart from a processing line of the brittle material substrate; And laser processing the substrate from the back surface to the front side of the substrate along a processing line of the substrate, thereby suppressing the occurrence of chipping of the substrate upon cutting the brittle material substrate The defective rate can be lowered and the production efficiency can be improved.

Description

TECHNICAL FIELD [0001] The present invention relates to a brittle material substrate,

The present invention relates to a method of processing a brittle material substrate, and more particularly, to a brittle material substrate processing method capable of suppressing chipping of a substrate when cutting a brittle material substrate.

Generally, when cutting a brittle material substrate such as a glass substrate or a semiconductor wafer, an indeterminate rupture called normal chipping occurs along the edge of the cut line.

On the other hand, in recent years, a method using a laser beam has been widely used as a non-contact type processing method when cutting a brittle material substrate.

In the method of processing a substrate using a laser beam, the substrate is processed by irradiating the substrate with a laser beam emitted from a laser oscillator through a laser optical system. In the method of processing a brittle material substrate using a laser beam, a beam spot is formed on a portion to be processed of the substrate, and the substrate is processed by applying heat energy, so that precision processing is possible and the processing time can be reduced.

However, in the method of processing a brittle material substrate using such a laser beam, when cutting a brittle material substrate, chipping may occur at the edge of the substrate where the cutting process is terminated due to energy condensation due to thermal conduction have.

Accordingly, an object of the present invention is to provide a method of processing a brittle material substrate capable of suppressing chipping of a substrate when cutting a brittle material substrate.

According to an aspect of the present invention, there is provided a machining method for preventing chipping from occurring around a machining line of a brittle material substrate using a laser beam, the machining method comprising: Laser processing the front surface of the substrate into a groove having a predetermined depth along a guide line; And a laser processing step of performing cutting in a thickness direction of the substrate from the rear surface (rear surface) of the substrate to the front side along the processing line.

The method of processing the brittle material substrate may further include moving the beam spot of the laser to the back surface of the substrate after laser processing the entire surface of the substrate to a predetermined depth along the guide line.

In the laser processing step, the substrate can be processed by moving the beam spot of the laser beam by the laser optical system while the substrate is fixed.

The laser used in the laser processing may be a nano second pulsed laser.

The guide line may be spaced apart from the processing line by 40 to 100 占 퐉 based on the beam spot size of the laser.

The processing depth of the guide line may be 40 to 60 탆.

The guide lines may be provided on both sides of the processing line at a predetermined interval.

According to the method for processing a brittle material substrate of the present invention, it is possible to suppress the occurrence of chipping of the substrate when cutting a brittle material substrate.

Thereby, there is an effect that the defective rate can be lowered and the production efficiency can be improved when cutting the brittle material substrate.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view showing a surface of a substrate processed by a method of processing a brittle material substrate according to an embodiment of the present invention; FIG.
2 is a cross-sectional view taken along the line II-II in Fig.
Fig. 3 is a view for explaining the crack diffusion preventing effect in the substrate of Fig. 1. Fig.
4 is a flowchart of a method of processing a brittle material substrate according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals as in the drawings denote like elements, unless they are indicated on other drawings. In addition, the preferred embodiments of the present invention will be described below, but it is needless to say that the technical idea of the present invention is not limited thereto, and various modifications may be made by those skilled in the art.

FIG. 1 is a view showing a surface of a substrate processed by a brittle material substrate processing method according to one embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 1 and FIG. 2 conceptually show only the main feature parts in order to conceptually clearly understand the present invention.

4 is a flowchart of a method of processing a brittle material substrate according to an embodiment of the present invention.

Referring to FIG. 4, a method of processing a brittle material substrate according to an embodiment of the present invention includes laser processing a front surface of a substrate to a predetermined depth along a guide line spaced apart from a processing line of a brittle material substrate (S200) of moving the beam spot of the laser to the rear surface of the substrate (S100); and laser-processing the substrate in the front direction from the back surface of the substrate (S300) along the processing line of the substrate.

In step S100 of laser processing the front surface of the substrate to a predetermined depth along the guide line, grooves having a predetermined depth are formed on the entire surface of the substrate along the guide line by the laser processing apparatus.

Referring to FIGS. 1 and 2, the guide line is spaced apart from the machining line by a predetermined distance. The machining line is a line in which the substrate is actually machined, and the guide line is a line for forming a groove with a predetermined depth at a certain distance from the machining line.

The processing line shown in Fig. 1 is a line formed for hole cutting a part of the substrate.

A laser processing apparatus (not shown) used in this embodiment processes a substrate by irradiating a substrate with a laser beam emitted from a laser oscillating section through a laser optical system. The control unit of the laser processing apparatus controls the laser optical system to form a beam spot of the laser on a portion of the substrate to be processed, thereby processing the substrate.

That is, the laser processing apparatus controls the laser optical system while moving the brittle material substrate to be processed in the fixed position, and moves the beam spot along the guide line to process the substrate.

In the laser machining apparatus, the beam spot can be moved by the laser optical system also in the X, Y and Z-axis directions (the thickness direction of the substrate) shown in Figs. 1 and 2. Therefore, the laser machining apparatus moves the beam spot along the guide lines in the X and Y axes to process the substrate, while moving the Z axis to move the entire surface of the substrate to a certain depth.

In step S200 of moving the beam spot of the laser to the rear surface of the substrate, after the groove machining is completed along the guide line on the entire surface of the substrate, the laser processing apparatus controls the laser optical system with the laser output turned off The position at which the beam spot is formed is moved onto the processing line on the back side of the substrate. At this time, since the position of the beam spot is moved only by the laser optical system while the substrate is fixed, it is possible to perform precise machining without misalignment due to the movement of the substrate.

In step S300 of laser-processing the substrate from the rear side to the front side of the substrate along the processing line of the substrate, the substrate is cut from the rear side to the front side along the processing line by the laser processing device.

In this step S300, the substrate remains fixed, and the substrate is processed while the beam spot is moved along the back surface processing line of the substrate by the laser optical system of the laser processing apparatus. The substrate is moved along the processing line and the Z-axis is moved toward the front side from the rear surface of the substrate at a constant speed, so that the substrate is cut along the processing line.

The function of the brittle material substrate processing method having such a structure will be described below.

The grooves having a predetermined depth formed along the guide line on the front surface of the substrate are formed such that chipping or cracks generated along the edge of the cutting line in the portion where the cutting processing of the substrate is completed when the substrate is cut along the processing line .

Fig. 3 is a view for explaining the crack diffusion preventing effect in the substrate of Fig. 1. Fig.

Referring to FIG. 3, the processed guide line on the front surface of the pre-formed substrate prevents the crack generated along the edge of the front part processing line of the substrate on which the cutting of the substrate is completed from spreading out of the guide line.

Accordingly, there is an effect that the chipping can be minimized and the defect rate of the product can be reduced.

The chipping generated at the edge of the cutting line at the time of cutting the substrate using the laser mainly occurs at the edge of the point where the cutting process ends because of energy condensation due to heat conduction. Therefore, the processed guide line is formed with grooves in advance in the front portion where the cutting process of the substrate is finished, thereby preventing the crack from spreading during the occurrence of chipping, thereby reducing the product defect rate.

The guide line is spaced apart from the machining line in consideration of the beam spot size of the laser. If the guideline is too close to the machining line, the preformed groove along the guideline can be laser machined together at the machining along the machining line. Also, when the guide line is too far from the machining line, there may be no effect of preventing the spread of chipping occurring at the edge of the machining line. Therefore, it is preferable that the guideline has an interval of 40 to 100 mu m with the processing line in consideration of such conditions.

The machining depth of the guide line is determined in consideration of the area where chipping mainly occurs. In addition, if there is an enhancement layer on the substrate, the enhancement layer is prone to chipping and is processed to a depth enough to penetrate the enhancement layer. Generally, it is preferable to process the guide line to a depth of 40 to 60 탆 considering the processing efficiency.

The method of working a brittle material substrate of the present invention has the following effects.

First, as described above, it is possible to prevent the chipping or cracks spreading along the edge of the cutting line when cutting the brittle material substrate, thereby reducing the product defect rate and improving the productivity.

Second, since the substrate is fixed and the laser optical system is controlled to move only the beam spot of the laser, the processing accuracy is high.

Third, it is possible to reduce the production cost by using a nanosecond pulse laser when laser processing a brittle material substrate. A pico second pulse laser may be used to reduce thermal damage to the substrate during laser processing of the brittle material substrate and to reduce chipping and cracking. However, the processing equipment using the picosecond pulsed laser has a higher cost than the processing equipment using the nanosecond pulsed laser, which increases the manufacturing cost. However, in the case of using the processing method of the present invention, the defective rate can be reduced even by the processing equipment using the nanosecond pulsed laser, thereby reducing the production cost.

On the other hand, in the above-described embodiments, although the invention has been described with respect to a processing line for performing a hole cutting process on a certain area of a brittle material substrate, various modifications are possible.

For example, the machining method of the present invention can be used not only for cutting a certain area of a substrate but also for cutting a substrate. In this case, guide lines may be provided on both sides of the processing line of the substrate at a predetermined interval. That is, in the hole cutting process, since the hole-cut portion is discarded, it is not necessary to form the guide line at the portion where the hole is to be cut. However, if both sides of the machining line are used, Is formed and processed.

It will be apparent to those skilled in the art that various modifications, substitutions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. will be. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are to be construed as illustrative rather than limiting, and the scope of the present invention is not limited by these embodiments and the accompanying drawings . It is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

10: substrate
11: Processing line
12: Guidelines

Claims

As a processing method for preventing occurrence of chipping around a processing line of a substrate at the time of cutting a brittle material substrate using a laser beam,
Laser processing a front surface of the substrate into a groove having a predetermined depth along a guide line spaced apart from the processing line; And
And performing laser cutting along a thickness direction of the substrate from the rear surface of the substrate to the front along the processing line.

The method according to claim 1,
After laser processing the front surface of the substrate to a predetermined depth along the guide line,
Further comprising moving a beam spot of the laser to the backside of the substrate.

3. The method according to claim 1 or 2,
In the laser processing step,
Wherein the substrate is processed by moving a beam spot of the laser by a laser optical system while the substrate is fixed.

3. The method according to claim 1 or 2,
Wherein the laser used in the laser processing is a nanosecond pulsed laser.

3. The method according to claim 1 or 2,
Wherein the guide line is spaced apart from the machining line by a distance of 40 to 100 占 퐉 based on a beam spot size of the laser.

3. The method according to claim 1 or 2,
And the working depth of the guide line is 40 to 60 占 퐉.

3. The method according to claim 1 or 2,
Wherein the guide lines are provided on both sides of the processing line at a predetermined interval.