JP2001130921A - Method and device for processing brittle substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely break a brittle substrate by generating fine cullet in a breaking process carried out at the last step in a laser processing machine. SOLUTION: In this invention a brittle substrate is completely broken without forcing external stress by irradiating laser after carrying out a usual processing by laser irradiation and coolant spraying.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for processing a brittle substrate by laser irradiation. Brittle substrates include semiconductor wafers and glass substrates.

[0002]

2. Description of the Related Art In a glass scriber using a glass cutter wheel, scribing is performed on a glass substrate which is a brittle substrate, whereby the glass substrate is bent so that cracks generated on the surface of the glass substrate are further accelerated. Is breaking on the scribed line.

[0003] A scribing method using a laser has been put to practical use instead of the conventional scribing method. This is because, as shown in FIG. 17, the laser beam from the laser 102 is applied to the glass substrate 101 moving in the direction of the arrow by the laser spot
The region heated by the laser beam irradiation is then cooled by the coolant jet 104, thereby generating internal strain stress in the glass substrate 101 and causing a crack (in this case, the crack is visually observed). Is called a blind crack because it cannot be confirmed). Thereafter, the glass substrate is bent in the same manner as in the conventional scribing method to break along the blind crack line.

[0004]

In the processing using the laser, no cullet is generated at the time of forming a blind crack, but fine cullet is generated in a breaking step performed by applying a mechanical external force. In the production line, there is a problem that the substrate breaking step must be performed in a space separated from the clean room.

Further, when the brittle substrate is thin and the moving speed of the table is slow, the brittle substrate can be cut by one laser irradiation, but there is a problem that the processing time is long and the production efficiency is poor.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method and an apparatus for processing a brittle substrate in which no cullet is generated.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a coolant is sprayed after laser irradiation to form a blind crack on the surface of a brittle substrate, and then laser irradiation is further performed to accelerate the formation of the blind crack. The brittle substrate is completely broken (hereinafter referred to as full body processing). The first irradiation laser beam is an ellipse whose major axis coincides with the moving direction of the brittle substrate, but the second irradiation laser beam may be an ellipse as in the first case, Alternatively, one or more pairs of beam spots may be applied to both sides of the blind crack. Alternatively, irradiation may be performed with an odd or even number of symmetrically arranged beam spots across a line in which a blind crack is formed.

[0008]

FIG. 9 is a front view of a laser processing apparatus BS showing a first embodiment of the present invention. Pedestal 1
By rotating the ball screw 2 in the direction perpendicular to the plane of the drawing by the motor 3, the ball screw 2 moves along the two rows of rails 4 and 5 in the direction perpendicular to the plane of the drawing (Y direction). On the upper surface of the pedestal 1, a guide 6 and a ball screw 8 that is rotated by a motor 7 in the left-right (X) direction are provided. The ball screw 8 is screwed into a ball nut 10 provided on the second pedestal 9, whereby the pedestal 9 moves in the X direction along the guide 6 when the motor 7 rotates. A table 12 is provided on the pedestal 9 via a θ rotation mechanism 11, and a glass substrate 13 is suction-fixed on the table 12.

Reference numeral 14 denotes a laser oscillating unit. The laser light oscillated here is guided to a lens barrel unit 15 having a lens unit inside via a mirror, and an ellipse (the ellipse) narrowed down to a desired size by the lens unit. The glass substrate 13 is irradiated with a beam spot whose major axis coincides with the scribe direction.

A support unit 16 extending in the X direction is provided at a lower end of the lens barrel 15, and a cutter wheel tip 17 is rotatably held on the right side of the center axis of the lens barrel 15. A tip holder 18 is provided so as to be able to move up and down, and a nozzle 19 for blowing a water jet, He gas, N 2 gas or CO 2 gas as a coolant onto the glass substrate 13 is provided on the left side of the center axis of the lens barrel 15. It is installed at the spray angle.

The positions of the alignment marks photographed by the CCD cameras 20 and 21 for photographing the alignment marks imprinted on the glass substrate 13 are recognized by an image recognition device. Can be known. 22, 2
Reference numeral 3 denotes a monitor for displaying images captured by the CCD cameras 20 and 21.

FIG. 12 shows the operation of the laser processing apparatus BS.
It will be described according to. In step (A), the alignment mark of the glass substrate 13 is read, in step (B), a notch is formed in the end of the glass substrate 13, and in step (C), laser irradiation and refrigerant spraying are performed. Then, the table 12 is returned to the original position, and then the table 12 is moved to the left again. At this time, only the laser irradiation is performed, and the refrigerant is not sprayed.

In the laser processing apparatus BS shown in FIG. 9 and a laser processing apparatus W3 shown in FIG. 5 described later, when the coolant is sprayed at the time of the second laser irradiation, there is an effect of further promoting the formation of blind cracks.

Further, the laser processing apparatus BS can change the traveling direction of the beam by 90 ° by changing the mounting position of the laser oscillating section, changing the lens system of the lens barrel section 15, and the like. The device configuration is such that the optimal beam traveling direction can be selected according to the shape and dimensions of the target brittle substrate and the line arrangement.

FIG. 10 shows a system configuration using a laser processing apparatus BS. When the glass substrate 13 is a single plate, the processed glass substrate 13 is carried out to a stocker 54 by a transfer robot 52. In the case where 13 is bonded, the processed glass substrate 13 is placed on the intermediate table 53 by the transfer robot 52, and the glass substrate 13 is reversed (sucked on the opposite surface) to be turned upside down. In this state, the table is reset and the steps (A) to (D) of FIG. 12 are repeated.

FIG. 11 shows a system configuration for processing both surfaces of a glass substrate. The laser processing device BS1 performs one-body processing on one surface of the glass substrate, and then reverses the surface using a reverse intermediate table 53. The same full body processing is performed on the glass substrate that has been made in the second laser processing apparatus BS2.

FIG. 12 shows an example in which the second laser irradiation is performed successively every time one blind crack is formed by laser irradiation. However, after forming a plurality of blind cracks, each blind crack is formed. The second laser irradiation may be performed. In the second laser irradiation, the above-mentioned multi-point spot may be used.

When the blind crack is to be machined in a direction orthogonal to the direction, the table 12 is rotated by 90 °, and before and after the blind crack is formed, a cut is made by the cutter wheel chip 17 at the intersection of the street where the blind crack is to be formed. I will attach it.

In addition, a pulse laser may be used to make a cut at the intersection of the street where the blind crack is to be formed.

FIG. 13 shows a laser irradiation apparatus L according to a second embodiment of the present invention. This apparatus L is the same as the laser processing apparatus BS shown in FIG. 9 except that the chip holder 18 and the coolant spray nozzle 19 are removed. This laser irradiation device L is not used alone,
As shown in the system diagram of 5, the laser processing equipment BS and BS
1. Used in combination with BS2.

FIG. 14 is a system diagram for processing a single glass substrate. The system includes, from the left, a stocker 51, a laser processing device BS, a laser irradiation device L, and a stocker 54. And a robot 52a for transferring the glass substrate from the table to the intermediate table 53, and supplying the glass substrate of the intermediate table 53 to the table of the laser irradiation device L.
4 comprises a robot 52b to be carried out.

The operation of these devices BS and L will be described with reference to FIG. In step (A), the CCD camera 2
At 0 and 21, the alignment marks on the glass substrate 13 are read. In step (B), a cut is made at the end of the glass substrate 13. Subsequently, blind cracking is performed by laser irradiation and refrigerant spraying. The glass substrate 13 is transferred to the laser irradiation device L by the robot 52b. (C) After the alignment marks are read by the CCD cameras 20 ′ and 21 ′ of the device L and the position of the table 12 is corrected based on the alignment marks, in step (D), only the laser irradiation is performed by the lens barrel 15 ′. Full body processing is performed.

FIG. 15 shows a system for double-sided processing, which is provided with a laser processing device BS1, a laser irradiation device L1, a laser processing device BS2, and a laser irradiation device L2 from the left. Then, one surface of the glass substrate is subjected to full body processing by laser irradiation twice, and the glass substrate is placed on the intermediate table 53b.
, And the other surface is similarly subjected to full-body processing by laser irradiation twice on the other surface in the laser processing device BS2 and the laser irradiation device L2.

In this case, a second laser irradiation is performed on each of the blind cracks after forming the blind cracks.

FIG. 1 is a front view of a laser processing apparatus W according to a third embodiment of the present invention. The configuration further includes a laser oscillation unit 31 and a lens barrel 32 which are equivalent to the laser oscillation unit 14 and the lens barrel 15 of the laser processing apparatus BS. Other components are the same as those of the first embodiment shown in FIG.

FIG. 2 shows a system diagram employing the present laser processing apparatus W. The stocker includes a stocker 51 for stocking unprocessed glass substrates, a transfer robot 52 for transferring glass substrates, an intermediate table 53 used for turning over glass substrates, and a stocker 54 for stocking processed glass substrates.

FIG. 4 shows a processing procedure in the present laser processing apparatus W. In step (A), the transfer robot 52
Substrate 13 supplied from stocker 51 by
However, the movement of the table 12 causes the CCD cameras 20, 21 to move.
, And the alignment mark of the glass substrate 13 is read, whereby the displacement at the time of setting the glass substrate 13 is recognized. In order to correct the shift amount, movement of the table 12 in the Y direction, movement of the table 12 in the X direction, and θ rotation of the table 12 by the θ rotation mechanism 11 are performed.

In step (B), the table 12 moves at a predetermined speed to the left in the figure with the chip holder 18 lowered by a predetermined amount. As a result, when the cutter wheel chip 17 rides on the glass substrate 12, a cut is made at the end of the glass substrate. After this, the chip holder 18 immediately rises.

In the step (C), while the glass substrate 13 passes below the lens barrel 15, a blind crack is formed by laser irradiation and blowing of a coolant. Steps
In (D), when the glass substrate 13 passes below the second barrel 32, laser irradiation is performed again, and the formation of the blind crack is promoted, whereby the glass substrate is completely broken.

In the case of performing a plurality of breaks, the above-described series of operations is repeated each time the table 12 is moved in one direction of X or Y, or a plurality of blind cracks are formed first. A second laser irradiation is performed on each blind crack. When processing is also performed in a direction orthogonal to the blind cracks, the table 12 is rotated by 90 °, and before and after the blind cracks are formed, the intersection of the streets forming the blind cracks is cut by the cutter wheel chip 17. .

In addition, a pulse laser may be used to make a cut at the intersection of the street where the blind crack is formed.

When the glass substrate 13 is a single plate, the processed glass substrate 13 is carried out to the stocker 54 by the transfer robot 52. When the glass substrate 13 is bonded, the processed glass substrate 13 is used. Is placed on the intermediate table 53 by the transfer robot 52, and the glass substrate 13 is replaced (sucked on the opposite surface),
The table 12 is set again with the front and back reversed, and the steps (A) to (D) of FIG. 4 are repeated again.

FIG. 3 shows a second system configuration.
The laser processing apparatus W shown in FIG.
A table is installed, an intermediate table 53 is installed between both machines, and a stocker 51 and a transfer robot 52 are installed for the apparatus W1.
a, and a stocker 54 and a transfer robot 52b are provided for the apparatus W2. These transfer robots 52a and 52b are the same as the transfer robot 52 of FIG.

In the laser processing apparatus W, a plurality of laser oscillators can be mounted, and the mounting position of the laser oscillator can be changed,
By changing the lens system of the lens barrel, it is possible to change the running direction of the laser beam by 90 °. When two laser oscillating units are mounted and the running speed of the beam is slow, two laser beams are full. It is possible to perform body machining. In addition, after forming a plurality of blind cracks two by two, a second laser irradiation may be sequentially performed two by two to perform full body processing. Alternatively, by changing the traveling direction of the 90 ° beam, 2
The apparatus is configured so that laser irradiation can be performed synchronously at a location.

In the laser processing apparatus W of FIG. 1, the lens barrel 15 and the second lens barrel 32 are arranged in the scribe (X) direction, but the lens barrels are arranged in the (Y) direction orthogonal to the scribe direction. Is also good. In that case, after laser irradiation by the lens barrel 15,
The table 12 is moved in the Y direction so that the same location can be irradiated with the laser beam by the second lens barrel 32.

The laser processing apparatus W3 shown in FIG. 5 has the same support unit 33 as the support unit 16
However, the tip holder 34 and the cutter wheel tip 35 are provided left and right opposite to those in the support unit 16.

In the laser processing apparatus W3, the table 12
When moving to the left, the same operation as the device in FIG.
(Only laser irradiation is performed in the second lens barrel 32).
When the table moves rightward, the second lens barrel 3
Laser irradiation and refrigerant spraying are performed in 2
By performing only laser irradiation, full-body processing can be performed by laser irradiation twice even when the table 12 moves in any direction.

In the laser processing apparatus W3 shown in FIG.
The second lens barrel 32 and the second lens barrel 32 are arranged in the (X) direction parallel to the paper surface.
By changing the lens systems 5 and 32, the oblong direction of the beam emitted from them is rotated by 90 °. By doing so, it becomes possible to select a mode of another laser processing method with the same processing apparatus. That is, in the initial arrangement of FIG. 1, after forming one BL, the same BL
In the processing apparatus after rotating the lens system by 90 °, the first laser irradiation is performed simultaneously in two places (two rows) at the same time. 2
The BLs of the book are formed in parallel at the same time, and the next second laser irradiation is performed simultaneously in two places (two rows) at the same time, and the cutting is performed simultaneously in two places.

FIG. 6 shows a positional relationship between beam spots in the laser processing apparatus W of FIG. B1 and C
Is a beam spot by the lens barrel 15 and a cooling spot by blowing the coolant, B2 is a beam spot by the second lens barrel 32, and both are located on the blind crack BL. The beam spot is an ellipse in this case.

FIG. 7 shows a multipoint spot B3 instead of the beam spot B2 in FIG. In the multipoint spot B3, each spot is not on the blind crack BL, and two pairs of spots are irradiated on both sides thereof. When such a multipoint spot B3 is used, a better scribe result may be obtained. The above multi-point spot,
As in B3 ', an odd number may be arranged symmetrically in the blind crack BL.

In order to obtain a multi-point spot, a beam splitter 38 may be attached to the lower end of the second lens barrel 32 as shown in the laser scribe device of FIG. The beam splitter 38 divides one laser beam into a plurality of beams using a plurality of half mirrors. By changing the position and angle of each half mirror, the distance a from the cooling spot C and the intervals b and c between the spots can be adjusted.

[0042]

As described above, according to the present invention, the brittle substrate is formed by further performing laser irradiation after performing ordinary blind crack processing by laser irradiation and refrigerant spraying to further promote the formation of blind cracks. Since the break is completely performed without applying a mechanical external stress, no cullet is generated because no mechanical break process is involved, and the break can be performed in a clean environment. Further, the brittle substrate can be cut efficiently by completely cutting the brittle substrate by two laser irradiations, and the processing time can be shortened.

[Brief description of the drawings]

FIG. 1 is a front view of a laser processing apparatus showing one embodiment of the present invention.

FIG. 2 is a system configuration diagram of the apparatus of FIG. 1;

FIG. 3 is another system configuration diagram of the apparatus of FIG. 1;

FIG. 4 is a diagram showing a flow of an operation in the apparatus of FIG. 1;

FIG. 5 is a front view of a laser processing apparatus showing another embodiment of the apparatus shown in FIG. 1;

FIG. 6 is a diagram showing a positional relationship between beam spots in the apparatus shown in FIG. 1;

FIG. 7 is a diagram showing a positional relationship between beam spots in the apparatus shown in FIG. 8;

FIG. 8 is a front view of a laser processing apparatus showing another embodiment of the apparatus shown in FIG. 1;

FIG. 9 is a front view of a laser processing apparatus according to a second embodiment of the present invention.

FIG. 10 is a system configuration diagram of the apparatus of FIG. 9;

11 is another system configuration diagram of the apparatus of FIG. 9;

FIG. 12 is a diagram showing a flow of an operation in the apparatus of FIG. 9;

FIG. 13 is a front view of a laser irradiation apparatus according to a third embodiment of the present invention.

14 is a system configuration diagram of the apparatus of FIG.

FIG. 15 is another system configuration diagram of the apparatus of FIG.

FIG. 16 is a diagram showing a flow of an operation in the apparatus of FIG. 13;

FIG. 17 shows a scribe method using a laser.

[Explanation of symbols]

 Reference Signs List 1 pedestal 11 θ rotation mechanism 12 table 13 glass substrate 14, 31 laser oscillation unit 15, 32 lens barrel unit 17 cutter wheel tip 18 chip holder 19 nozzle 20, 21 CCD camera 22, 23 monitor 38 beam splitter

Continuation of the front page (72) Inventor Masahiro Fujii 2-6-5 Esakacho, Suita-shi, Osaka F-term (reference) in Samsung Diamond Industrial Co., Ltd. 4E068 AD00 CB06 CD04 CE01 CE11 CH08 DA10 DB13 4G015 FA06 FB02 FC10 FC11 FC14

Claims (12)

[Claims] 1. A method in which a coolant is sprayed after laser irradiation to form a blind crack on the surface of a brittle substrate, and further laser irradiation is performed to promote the formation of the blind crack and completely break the brittle substrate. Processing method for brittle substrates. 2. A brittle substrate processing apparatus (BS) comprising a table on which a brittle substrate is set, a table moving mechanism for moving the table, and a laser irradiating means and a coolant spraying means along a moving direction of the table. In), while moving the table in one direction, after performing laser irradiation and coolant spraying by the laser irradiation means and coolant spraying means, return the table to its original position, when moving the table again An apparatus for processing a brittle substrate, wherein the apparatus is controlled to perform only laser irradiation. 3. A brittle substrate processing apparatus (BS) comprising a table on which a brittle substrate is set, a table moving mechanism for moving the table, and a laser irradiation unit and a coolant spraying unit along a moving direction of the table. A laser irradiation device (L) used in addition to the above, comprising: a table on which a brittle substrate is set; a table moving mechanism for moving the table; and a laser irradiation for the brittle substrate on the moving table. A laser irradiation device comprising a laser irradiation unit. 4. A laser beam emitted by said laser irradiating means is radiated as a multipoint beam by a beam splitter.
An apparatus for processing a brittle substrate as described in the above. 5. A table on which a brittle substrate is set, a table moving mechanism for moving the table, a first laser irradiating unit, a coolant spraying unit, and a second laser irradiating unit. An apparatus (W) for processing a brittle substrate, wherein the brittle substrate is subjected to laser irradiation by a first laser irradiating unit and sprayed with a refrigerant, and then to laser irradiation by a second laser irradiating unit. 6. An apparatus for processing a brittle substrate according to claim 5, wherein the laser beam emitted from the second laser irradiating means is irradiated as a multipoint beam by a beam splitter. 7. A table on which a brittle substrate is set, a table moving mechanism for moving the table, a first laser irradiating unit, a coolant spraying unit, and a second laser irradiating unit. A brittle substrate processing apparatus (W) for performing laser irradiation by a first laser irradiation unit and spraying a coolant on a brittle substrate, and then performing laser irradiation by a second laser irradiation unit; and an intermediate table for brittle substrate inversion ( 53), setting an unprocessed brittle substrate on the table, turning the brittle substrate having one surface processed on an intermediate table (53), setting the brittle substrate on the table, and setting the other surface Robot (5) to discharge the processed brittle substrate to the next process
2) A processing line comprising: 8. A table on which a brittle substrate is set, a table moving mechanism for moving the table, a first laser irradiating unit, a coolant spraying unit, and a second laser irradiating unit. Two processing apparatuses (W1 and W2) for performing laser irradiation by the first laser irradiation unit and refrigerant spraying on the brittle substrate and then performing laser irradiation by the second laser irradiation unit; A table (53), a robot (52a) for setting an unprocessed brittle substrate on the table of the processing device (W1), and placing the brittle substrate having one surface processed on the intermediate table (53); A robot (52b) for setting the brittle substrate in (53) in an inverted state on a table of the processing apparatus (W2) and discharging the brittle substrate having the other surface processed to the next step. Processing line 9. A table on which a brittle substrate is set, a table moving mechanism for moving the table, a laser irradiating unit and a refrigerant spraying unit along a moving direction of the table, and the table is moved in one direction. In the meantime, after the laser irradiation and the coolant spraying means perform the laser irradiation and the coolant spraying, the table is returned to the original position, and again, the brittle substrate which performs only the laser irradiation when the table is moved in one direction. A processing device (BS), an intermediate table (53) for brittle substrate inversion, and an unprocessed brittle substrate are set on the table, and the brittle substrate with one surface processed is inverted on the intermediate table (53). After that, the brittle substrate is set on the table, and the other surface of the processed brittle substrate is discharged to the next step by the robot (5).
2) A processing line comprising: 10. A table on which a brittle substrate is set,
A table moving mechanism for moving the table, a laser irradiating means and a refrigerant spraying means along a moving direction of the table, and a laser irradiating means and a refrigerant spraying means while moving the table in one direction; After the irradiation and the spraying of the refrigerant, the table is returned to the original position, and again, when the table is moved in one direction, the two processing apparatuses that perform only the laser irradiation
(BS1, BS2), an intermediate table (53) for brittle substrate reversal, and an unprocessed brittle substrate are set on the table of the processing apparatus (BS1), and the brittle substrate having one surface processed is placed on the intermediate table (53). ) And the brittle substrate on the intermediate table (53) are set on the table of the processing device (BS2) in a state where the brittle substrate is turned upside down. A processing line comprising a robot (52b) for discharging. 11. A table on which a brittle substrate is set,
A table moving mechanism for moving the table, a brittle substrate processing apparatus (BS) including a laser irradiation unit and a coolant spraying unit along a moving direction of the table, a table on which the brittle substrate is set, and the table Table moving mechanism for moving the substrate in one direction, a laser irradiation device (L) having laser irradiation means, an intermediate table (53) for reversing the brittle substrate, and a table of a processing device (BS) for processing the unprocessed brittle substrate. To the intermediate table (5)
3) a robot (52a) placed on the intermediate table (53), and a brittle substrate on the intermediate table (53) are set on a table of a laser irradiation device (L); A processing line comprising a robot (52b) for discharging to a next step. 12. A table on which a brittle substrate is set,
Two processing apparatuses (BS1, BS1) each including a table moving mechanism for moving the table, and a laser irradiation unit and a refrigerant spraying unit along a moving direction of the table.
2), a table on which the brittle substrate is set, a table moving mechanism for moving the table in one direction, and two laser irradiation devices (L1, L2) each provided with a laser irradiation unit; Intermediate table (53a, 53
c), an intermediate table for inverting the brittle substrate (53b), and setting the unprocessed brittle substrate on the table of the processing apparatus (BS1),
The robot (52a) placed on the (53a) and the brittle substrate on the intermediate table (53a) are set on the table of the laser irradiation device (L1), and the brittle substrate irradiated with the laser again on the one surface is set. A robot (52b) for placing the substrate on the intermediate table (53b), and setting the brittle substrate on the intermediate table (53b) in a reversed state on the table of the processing device (BS2), and processing the brittle substrate on the other surface A robot (52c) for placing the laser beam on the intermediate table (53c), and setting the brittle substrate on the intermediate table (53c) on the table of the laser irradiation device (L2), and the other surface is again irradiated with the laser. A robot (52d) for discharging the brittle substrate to the next step.