JPWO2009145008A1 - Laser processing apparatus and laser processing method - Google Patents

Abstract

Provided are a laser processing method and a laser processing apparatus using a cooling method based on solid contact that does not have a problem of metal powder generation and a problem of dirt adhering to a cooling member adhering to a substrate and does not generate scratches due to friction. A laser irradiation mechanism for forming a beam spot on a brittle material substrate, a substrate cooling mechanism for forming a cooling region, the beam spot, and the cooling region along the planned processing line set on the substrate. The substrate cooling mechanism includes a solid-phase refrigerant that is solidified by cooling a refrigerant material that is gas or liquid at room temperature, and a pressing mechanism that causes the solid-phase refrigerant to contact the substrate. Consists of.

Description

The present invention relates to a processing method and a processing apparatus for a brittle material substrate by laser irradiation, and more particularly, a laser processing method and a laser for generating cracks by applying thermal stress to the brittle material substrate by heating by laser irradiation and cooling immediately thereafter. It relates to a processing apparatus.
Here, the brittle material substrate refers to a glass substrate, a sintered ceramic material, a single crystal silicon, a semiconductor wafer, a sapphire substrate, a ceramic substrate, or the like.

Using laser scribing, which irradiates a brittle material substrate such as a glass substrate with a laser beam, scans the beam spot formed on the substrate, heats it in a line, and blows and cools the coolant immediately after heating. Compared with mechanical processing using a wheel or the like, the occurrence of cullet can be reduced, and the end face strength can be improved.
For this reason, laser scribing is employed in various manufacturing processes and the like that require cutting of glass substrates and the like including flat panel displays.

  In general, in laser scribing processing, a virtual line to be processed (referred to as a processing scheduled line) is set. Then, an initial crack (trigger) is formed on the substrate end, which is the starting end of the planned processing line, with a cutter wheel or the like, and a beam spot by laser beam irradiation is scanned along the planned scribe line from the position of the initial crack formed at the starting end. . Subsequently, cooling is performed by spraying a coolant on the processing scheduled line immediately after the beam spot passes. At this time, a stress gradient is generated based on the temperature distribution (depth direction temperature distribution or front-rear direction temperature distribution) generated in the vicinity of the processing line, resulting in a finite depth crack (called a scribe line) or the back surface of the substrate. And a crack (referred to as a full cut line) that completely divides the substrate is formed (see Patent Document 1, Patent Document 2, and Patent Document 3).

  In order to accurately form a crack along the planned processing line by laser scribing, it is necessary to generate a large thermal stress on the planned processing line, and it is necessary to form a steep temperature gradient along the planned processing line. is there. Laser scribing may be performed under conditions that allow the formation of cracks (scribe lines) with a finite depth as deeply as possible, or conditions that allow the formation of cracks (full cut lines) that can be completely cut off. For this purpose, it is necessary to form a temperature gradient as large as possible by cooling after heating. However, the method of spraying a gas (which may contain a liquid) in a non-contact state, which is a cooling method generally performed so far, may not be sufficiently cooled.

Therefore, as a cooling method for generating a large temperature gradient, a method is disclosed in which the cooling member is mechanically brought into contact with the substrate surface after the beam spot has passed.
For example, a cooling method is disclosed in which a cooling pipe in which a coolant circulates is brought into contact with a substrate (see Patent Document 4).

Further, a method is disclosed in which the tip of a roller-shaped cooling member (solid), a spherical cooling member (solid), or a rod-shaped cooling member is cooled to come into contact with the substrate surface at a low temperature (Patent Document 5). ).
In addition, a volatile liquid composed of a solvent having a vapor pressure higher than that of water at room temperature is infiltrated into a cooling member made of a material such as sponge or felt, and the cooling member (sponge or the like) is brought into contact with the substrate to make it volatile. It is also disclosed that the liquid is applied and cooled using the heat of vaporization when the volatile liquid evaporates (see Patent Document 5).
JP 2001-130921 A JP 2006-256944 A WO2003 / 008352 Publication JP 2002-100590 A JP 2002-362933 A

  In this way, the cooling pipe or roller-shaped cooling member is contacted, or the cooling member such as sponge or felt infiltrated with the volatile liquid is contacted, and the solid material is mechanically brought into contact with the substrate for cooling. If it carries out, it will become possible to cool efficiently along a process schedule line, and a crack can be formed accurately and reliably along a process schedule line.

  However, a metal (copper, aluminum) having a high thermal conductivity capable of cooling the contact surface to a low temperature is used for the cooling pipe or the roller-shaped cooling member. When such a cooling member moves while being in mechanical contact with the substrate, metal powder remains on the substrate due to friction, and the substrate is contaminated. In particular, when a small scratch occurs on the contact surface of the cooling member for some reason, metal powder is likely to be generated from the scratched portion. Further, since the scratched portion has a high coefficient of friction, the substrate is easily scratched by coming into contact with this portion.

  On the other hand, when using a cooling member such as sponge or felt infiltrated with volatile liquid, there is no problem of scratches due to metal powder or friction, but there is a risk that part of the sponge or felt may peel off and adhere to the substrate There is. Moreover, if dirt adheres to the sponge or felt, the dirt adheres to the substrate that comes into contact thereafter.

  Therefore, the present invention provides a problem that metal powder is generated from the cooling member itself and dirt attached to the cooling member on other substrates when the solid cooling member is mechanically contacted with the cooling after heating in the laser scribing process. It is an object of the present invention to provide a laser processing method and a laser processing apparatus using a cooling method that does not have a problem of adhesion and does not cause scratches due to friction.

The laser processing apparatus of the present invention made to solve the above-mentioned problems has been made by devising the property that a solid material to be brought into mechanical contact with a substrate as a cooling member must have.
In other words, the laser processing apparatus of the present invention is a laser processing apparatus for a brittle material substrate, and includes a laser irradiation mechanism for forming a beam spot on the substrate to perform local heating by irradiating the laser beam, and a local substrate. And a substrate cooling mechanism for forming a cooling region to be cooled automatically, and further, a beam spot irradiated by the laser irradiation mechanism and a cooling region formed by the substrate cooling mechanism are aligned with a planned processing line set on the substrate. And a scanning mechanism that relatively moves in the order of the beam spot and the cooling region. The substrate cooling mechanism uses a solid-phase refrigerant that is solidified by cooling a refrigerant material that becomes a gas or a liquid at room temperature, and includes a contact mechanism that contacts the solid-phase refrigerant with the substrate.

Here, the scanning mechanism that relatively moves the beam spot and the cooling region may move the substrate with the laser spot and the cooling region at a fixed position, or the laser irradiation mechanism with the substrate position fixed. The beam spot and the cooling region by the substrate cooling mechanism may be moved with respect to the substrate.
The “normal temperature” of the “refrigerant material that becomes a gas or liquid at normal temperature” refers to the normal temperature (room temperature) of the surrounding space where the laser scribing process is performed, specifically 5 ° C. to 40 ° C. Refers to the temperature range.

  According to the present invention, the substrate cooling mechanism brings the solid-phase refrigerant that has been solidified by cooling the refrigerant material that becomes a gas or a liquid at room temperature into contact with the substrate by the pressing mechanism. The solid-phase refrigerant is scanned along the scheduled processing line heated immediately before, while one end surface is in contact with the substrate. As a result, the processing line of the substrate is efficiently and accurately cooled by the contact surface of the solid-phase refrigerant, and the contact surface of the solid-phase refrigerant is vaporized, liquefied, and consumed.

  According to the present invention, efficient cooling can be performed on the contact surface with the solid-phase refrigerant, and the solid-phase refrigerant is not damaged by friction, so that the substrate is hardly damaged. In addition, since the contact surface is vaporized or liquefied during cooling, it will be consumed, so even if the substrate is cooled one after another with the same solid phase refrigerant, the dirt adhering to the contact surface of the solid phase refrigerant will adhere to the next substrate. It will not be attached.

In the above invention, any one of ice, solid state alcohol, and dry ice may be used as the solid-phase refrigerant.
When ice is used as the solid-phase refrigerant and this is brought into contact with a heated substrate, a part of the ice is liquefied to become water. Further, when solid-state alcohol is used as the solid-phase refrigerant, a part thereof becomes liquid alcohol or gaseous alcohol. In addition, when dry ice is used as the solid phase refrigerant, a part thereof is vaporized into carbon dioxide. None of these materials contain a solid substance such as metal powder or sponge, so that they remain as solids on the substrate and do not damage or contaminate the substrate. Further, since it is a material that naturally evaporates at room temperature, it does not need to be removed, and even if it is attached in a liquid state that has not evaporated, it can be easily removed by washing with pure water.
Further, when ice, alcohol, or dry ice is brought into contact with the substrate as a solid-phase refrigerant, the solid temperature can be lowered as the temperature of the ice is reduced. Therefore, by cooling the solid-phase refrigerant to a low temperature, the cooling efficiency can be further increased, and a steep temperature gradient can be formed to perform accurate processing.

In the above invention, the substrate cooling mechanism further includes: a refrigerant supply unit that supplies the refrigerant material; and a solidification unit that cools the supplied refrigerant material to a temperature equal to or lower than a temperature at which the refrigerant material solidifies to form a solid phase refrigerant. You may make it prepare.
According to this, when a part of the solid-phase refrigerant is vaporized or liquefied and consumed, the exhausted solid-phase refrigerant is supplied by supplying the refrigerant material from the refrigerant supply unit and cooling to the solidification temperature to form the solid-phase refrigerant. Can be added, and cooling can be performed continuously. Moreover, even if the solid-phase refrigerant is damaged, it can be repaired.

Here, the refrigerant supply unit includes a nozzle for injecting the refrigerant material, and the solidification unit is provided with an end surface facing the substrate and the core material arranged so that the refrigerant material injected from the nozzle adheres to the end surface And a core material cooling section that cools the end face of the core material to a temperature equal to or lower than the temperature at which the refrigerant material is solidified.
According to this, the refrigerant material adhering to the end face of the core material is solid by injecting the refrigerant material from the nozzle onto the end face of the core material (for example, a copper rod having a rounded front end face) cooled by the core material cooling unit. The solid-state refrigerant can be formed by being cooled to a temperature equal to or lower than the conversion temperature and solidifying and adhering to the end surface of the core material, and covering the end surface of the core material.
And the board | substrate can be cooled efficiently by making the solid-phase refrigerant adhering to a core material end surface contact a board | substrate mechanically. At this time, since the core material itself does not directly contact the substrate, a part of the core material is not peeled off and the metal powder or the like does not remain.

In the above invention, the pressing mechanism may include a support member that removably supports the solid-phase refrigerant in a state where one end surface of the solid-phase refrigerant is opposed to the substrate.
According to this, the solid-phase refrigerant detachably attached by the support member is pressed against the substrate by the pressing mechanism. When the solid-phase refrigerant is consumed due to contact with the substrate, the used solid-phase refrigerant is removed and replaced with a new solid-phase refrigerant. Thereby, it can cool by a solid-phase refrigerant | coolant subsequently.

In the above invention, the substrate cooling mechanism may further include a shaping mechanism for shaping a contact surface of the solid phase refrigerant that contacts the substrate with respect to the solid phase refrigerant.
Here, the shape shaped by the shaping mechanism is not particularly limited. Specifically, the tip may be shaped into a hemisphere or may be shaped into a square shape. Further, it may be shaped into an ellipse so that it can be easily aligned with the planned processing line direction.

  Further, in order to solve the above-mentioned problem, the laser processing method of the present invention, which has been made from another viewpoint, scans a beam spot formed by laser beam irradiation along a planned processing line set on a brittle material substrate. Is a laser processing method of a brittle material substrate that forms a crack due to thermal stress along a planned processing line by cooling the substrate immediately after passing through the beam spot, and cooling the substrate at room temperature. The cooling is performed by bringing a solid-phase refrigerant that is solidified by cooling a refrigerant material that becomes a gas or a liquid into contact with the substrate.

  According to the present invention, efficient cooling can be performed on the contact surface with the solid-phase refrigerant, and the solid-phase refrigerant is not damaged by friction, so that the substrate is hardly damaged. In addition, since the contact surface is vaporized or liquefied during cooling, it will be consumed, so even if the substrate is cooled one after another with the same solid phase refrigerant, the dirt adhering to the contact surface of the solid phase refrigerant will adhere to the next substrate. It will not be attached.

In the above method, any one of ice, solid alcohol, and dry ice may be used as the solid-phase refrigerant.
Since these materials do not contain a solid substance such as metal powder or sponge, they can be processed without remaining as a solid on the substrate and damaging or soiling the substrate. Further, since it is a material that naturally evaporates at room temperature, it does not need to be removed, and even if it is attached in a liquid state that has not evaporated, it can be easily removed by washing with pure water.

Here, the solid phase refrigerant may contain a surfactant or a cleaning agent as an additive.
By containing a surfactant, the surfactant is applied to the cracks formed along the planned processing line when cooled with a solid-phase refrigerant, and as a result, the surfaces of the cracks adhere to each other. Can be prevented. Further, by including the cleaning agent, the cleaning agent is applied to the processing scheduled line when cooled by the solid phase refrigerant, and as a result, the cleaning can be performed easily and efficiently.

1 is an overall configuration diagram of a substrate processing apparatus according to an embodiment of the present invention. The partial block diagram which shows the structure of the board | substrate cooling mechanism which is a part of the board | substrate processing apparatus of FIG. The block diagram which shows the control system of the board | substrate processing apparatus of FIG. The figure which shows the process operation procedure by the board | substrate processing apparatus of FIG. The whole block diagram of the board | substrate processing apparatus which is 2nd embodiment of this invention. The figure which shows the structure of the heating block in FIG. The figure which shows the operation | movement procedure of the shaping mechanism in the board | substrate processing apparatus of FIG. The whole block diagram of the substrate processing apparatus which is 3rd embodiment of this invention. The partial block diagram which shows the structure of the board | substrate cooling mechanism which is a part of board | substrate processing apparatus of FIG.

2 Slide table 7 Base (scanning mechanism)
12 rotary table 13 laser device (laser irradiation mechanism)
14 Optical holder (laser irradiation mechanism)
20, 20a Substrate cooling mechanism 21 Core material (solidification part)
21a End surface 22 Core material cooling part 24 Lifting rod 25 Pressing mechanism 26 Lifting mechanism 27 Nozzle (refrigerant supply part)
50 Shaping mechanism 51 Heating block 52 Moving mechanism 61 Support member A Glass substrate (brittle material substrate)
Cr crack CL solid phase refrigerant

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram of a substrate processing apparatus LS1 that can implement the processing method of the present invention. FIG. 2 is a partial configuration diagram showing a configuration of a substrate cooling mechanism that is a part of the substrate processing apparatus LS1.
In the present embodiment, a case where a glass substrate is processed will be described as an example, but the same applies to a brittle material substrate such as a silicon substrate. Although the case where ice is used as the solid phase refrigerant will be described, the same applies to other solid phase refrigerants (in the case of solid alcohol, liquid alcohol is used, and in the case of dry ice, liquefied carbon dioxide gas is used).

  First, the overall configuration of the substrate processing apparatus LS1 will be described. A slide table 2 that reciprocates in the front-rear direction (hereinafter referred to as the Y direction) in FIG. 1 is provided along a pair of guide rails 3 and 4 arranged in parallel on a horizontal base 1. A screw screw 5 is disposed between the guide rails 3 and 4 along the front-rear direction, and a stay 6 fixed to the slide table 2 is screwed to the screw screw 5. The slide table 2 is formed so as to reciprocate in the Y direction along the guide rails 3 and 4 by forward and reverse rotation (not shown).

  A horizontal base 7 is arranged on the slide table 2 so as to reciprocate in the left-right direction (hereinafter referred to as X direction) in FIG. A screw screw 10 that is rotated by a motor 9 is threaded through a stay 10a fixed to the pedestal 7, and the pedestal 7 is moved along the guide rail 8 in the X direction by rotating the screw screw 10a forward and backward. Move back and forth.

  On the pedestal 7, a turntable 12 that is rotated by a rotation mechanism 11 is provided. On the turntable 12, the glass substrate A is attached in a horizontal state. The glass substrate A is a mother substrate for cutting out a small unit substrate, for example. The rotation mechanism 11 is configured to rotate the rotary table 12 around a vertical axis, and is configured to be able to rotate at an arbitrary angle with respect to a reference position. Further, the glass substrate A is fixed to the rotary table 12 by a suction chuck.

Above the turntable 12, a laser device 13 and an optical holder 14 constituting a laser irradiation mechanism are held by an attachment frame 15.
As the laser device 13, a general device for processing a brittle material substrate may be used. Specifically, an excimer laser, a YAG laser, a carbon dioxide gas laser, a carbon monoxide laser, or the like is used. For processing the glass substrate A, it is preferable to use a carbon dioxide gas laser that oscillates light having a wavelength with high energy absorption efficiency of the glass material.

  The laser beam emitted from the laser device 13 has a beam spot having a long axis (elliptical shape, oval shape, etc.) on the glass substrate A by an optical holder 14 incorporating a lens optical system for adjusting the beam shape. Formed. Here, the shape of the beam spot is made into an ellipse so that it can be efficiently heated along the scribe line.

  The mounting frame 15 is provided with a substrate cooling mechanism 20 in the vicinity of the optical holder 14. As shown in FIG. 2, the substrate cooling mechanism 20 is mainly composed of two structures: a core member 21 made of a rod-like body and a nozzle 27 that ejects water (water vapor) that becomes liquid at room temperature. The core material 21 is formed of a metal having good heat conductivity (for example, copper or aluminum). The end surface 21a on the lower side of the core material 21 is a mirror surface with no unevenness. The end surface 21a is adapted to adhere the cooling medium ejected from the nozzle 27. Although the end surface 21a is hemispherical, it may have another shape, and may be an appropriate shape according to the shape and width of the beam spot to be scanned. Fins 21b are provided on the upper side of the core material 21 so that the core material 21 can be efficiently cooled via the fins 21b.

  A box-shaped core material cooling section 22 is provided around the fins 21b of the core material 21, and the cooling medium is introduced and discharged through the circulation channels 22a and 22b. The cooling medium used is a low-temperature fluid that can cool the temperature of the end face 21a to a desired temperature. For example, when water is ejected from the nozzle 27 as a refrigerant material, the end surface 21a only needs to be below the freezing point (0 ° C.), and therefore, a lower temperature gas (a freon gas cooled at a refrigeration circuit) or a liquid (a liquefied carbonic acid). The core material 21 is cooled using gas, liquid nitrogen). The core material 21 may be cooled by using a Peltier element in the core material cooling unit 22.

A heat insulating material 23 (for example, a ceramic plate) is attached to the upper surface of the core material cooling unit 22, and a lifting rod 24 is fixed to the upper surface of the heat insulating material 23. The heat insulating material 23 is attached to prevent the cooling heat of the core material cooling unit 22 from being transmitted to the lifting rod 24.
The lifting rod 24 is connected to a pressing mechanism 25 for bringing the core material 21 into contact with the substrate A. The pressing mechanism 25 moves the elevating rod 24 up and down by an elevating mechanism 26 composed of a coil spring and an electromagnetic valve (not shown) to elevate and lower the core material 21. When the core member 21 is lowered and is in contact with the substrate A, the end surface 21a is adjusted so as to press the substrate A with an appropriate force by the coil spring.

  The nozzle 27 has an injection direction directed toward the core material 21, and water (water vapor) supplied via the on-off valve 28 is injected from the nozzle 27 and adheres to the end surface 21 a. The water adhering around the core material 21 becomes ice and covers the end surface 21a because the core material 21 is cooled to 0 ° C. or less. Accordingly, when the core material 21 in this state is lowered and brought into contact with the substrate A, the ice portion adhering to the end surface 21a comes into contact with the substrate A, and the substrate A is thereby cooled.

Further, a cutter wheel 18 is attached to the attachment frame 15 via an elevating mechanism 17 on the side opposite to the substrate cooling mechanism 20 in the vicinity of the optical holder 14.
The cutter wheel 18 is used so as to temporarily descend from above when an initial crack is formed in the glass substrate A.

  Further, the substrate processing apparatus LS1 is equipped with a camera 19 capable of detecting a positioning alignment mark engraved on the glass substrate A. From the position of the alignment mark detected by the camera 19, the positional relationship between the position of the scheduled scribe line set on the substrate A and the rotary table 12 is obtained, and the position where the cutter wheel 18 is lowered and the position where the beam spot is irradiated are scribed. It can be positioned accurately so that it is on the planned line.

Next, a control system of the substrate processing apparatus LS1 will be described. FIG. 3 is a block diagram showing a control system of the substrate processing apparatus LS1. In the substrate processing apparatus LS1, each drive system of the laser / optical system drive unit 31, the substrate cooling mechanism drive unit 32, the scanning mechanism drive unit 33, the trigger mechanism drive unit 34, and the camera drive unit 35 is configured by a computer (CPU). The control unit 40 is controlled.
The control unit 40 is connected to an input unit 41 including input devices such as operation buttons, a keyboard, and a mouse, and a display unit 42 including a display screen for performing various displays, and necessary messages are displayed on the display screen. Necessary operations, instructions and settings can be input.

Next, an operation performed by each drive unit controlled by the control unit 40 will be described.
The laser / optical system drive unit 31 operates and stops the laser device 13 to perform the laser beam irradiation operation and the stop operation. When the laser beam is irradiated, an elliptical beam spot is formed on the substrate A through the lens optical system in the optical holder 14.

  The substrate cooling mechanism drive unit 32 first performs an operation of injecting the refrigerant from the nozzle 27 by controlling the on-off valve 28, and lowers the core material 21 by the control of the pressing mechanism 25 to adhere to the end surface 21a of the core material 21. An operation of bringing the ice layer into contact with the substrate A is performed.

  The scanning mechanism driving unit 33 drives the slide table 2, the pedestal 7, and the rotating mechanism 11 to perform the operation of moving the substrate A.

The trigger mechanism driving unit 34 drives the lifting mechanism 17 of the cutter wheel 18 to perform an operation of forming an initial crack in the substrate A.
The camera driving unit 35 operates to drive the camera 20 and display the position of the substrate A on the display unit 42.

  Next, the processing operation by the substrate processing apparatus LS1 will be described. FIG. 4 is a diagram showing a processing operation procedure of laser scribe processing by the substrate processing apparatus LS1.

First, as shown in FIG. 4A, the glass substrate A is placed on the turntable 12 and fixed by a suction chuck. An alignment mark (not shown) engraved on the glass substrate A is detected by the camera 20 (FIG. 1), and based on the detection result, the position of the processing scheduled line and the rotary table 12, the slide table 2, and the base 7 are detected. Are related. Then, the rotary table 12 and the slide table 2 are operated, and the position is adjusted so that the cutting edge direction of the cutter wheel 18 is aligned with the direction of the processing scheduled line. Further, in a state where the lifting mechanism 17 is operated and the cutter wheel 18 is lowered, the base 7 is operated, and the cutter wheel 18 is brought into contact with the end portion of the substrate A on the rotary table 12 so as to form an initial crack. To. After the initial crack is formed, the lifting mechanism 17 is operated to avoid the cutter wheel 18 from hitting the substrate A.
While performing the above operations, water (water vapor) is jetted from the nozzle 27 in parallel to adhere to the end surface 21a of the low-temperature core material 21, thereby forming an ice layer covering the end surface 21a. .

  Subsequently, as shown in FIG. 4B, the rotary table 12 (pedestal 7) is once moved to the original position, and then the laser light source 13 is operated to irradiate the laser beam. Then, the injection of water (water vapor) from the nozzle 27 is stopped. In this state, the base 7 is driven to start the movement of the rotary table 12.

  Subsequently, as shown in FIG. 4C, the substrate A passes through just below the laser beam by the movement of the turntable 12 (base 7). At this time, a beam spot is formed on the substrate A and heated. Furthermore, the ice adhering to the end surface 21a of the core member 21 comes into contact with the position immediately after the heating, so that it is efficiently cooled. At this time, a part of the ice melts, but it only becomes water, and no metal powder or the like that causes damage to the substrate is generated. Therefore, no scratch is formed on the substrate A. Then, a large temperature difference is formed by the contact of the solid phase refrigerant, so that a crack is formed along the planned processing line (that is, the line where the beam spot and ice have moved).

  Then, as shown in FIG. 4D, as a result of the movement of the beam spot and the ice on the processing line of the substrate A, a crack Cr is formed on the processing line of the substrate A. Note that the crack Cr becomes a scribe line composed of cracks of a finite depth depending on heating conditions, cooling conditions, and the thickness of the substrate, and also serves as a full cut line composed of cracks that completely divide the substrate.

(Embodiment 2)
FIG. 5 is an overall configuration diagram of the substrate processing apparatus LS2 according to the second embodiment of the present invention. In the figure, the same components as those of the substrate processing apparatus LS1 (FIG. 1) are denoted by the same reference numerals and description thereof is omitted. The substrate processing apparatus LS2 is different from the first embodiment in that it includes a shaping mechanism 50 for adjusting the size and shape of ice formed on the end surface 21a of the core member 21. This is the same as the embodiment. The control system is different in that the substrate cooling mechanism driving unit 32 is also driven for the up-and-down movement and the rotational movement of the shaping mechanism 50. Other controls are the same as those of the substrate processing apparatus LS1.

The shaping mechanism 50 includes a heating block 51 and a moving mechanism 56 that moves the heating block 51 up and down and rotationally to avoid the heating block 51 from colliding with the rotary table 12.
As shown in FIG. 6, the heating block 51 is formed with a mold hole 52 and a discharge hole 53 for inserting and shaping the tip portion of the core material 21, and an embedded heater 54 is attached. By energizing the embedded heater 54, the heating block 51 is heated.

FIG. 7 is a diagram showing an example of the shaping operation by the substrate processing apparatus LS2.
First, as shown in FIG. 7A, when the turntable 12 on which the glass substrate A is placed is in a processing start position away from the substrate cooling mechanism 20, the moving mechanism 56 is operated to heat the heating block. 51 is placed directly under the core material 21.

  Subsequently, as shown in FIG. 7B, the heating block 51 is raised so that the core material 21 is inserted into the mold cavity 52. At this time, a part of the ice layer adhering to the periphery of the core material 21 melts and is discharged from the discharge hole 53. As a result, the ice layer adhering to the surface of the core material is shaped into a hemisphere that is the bottom shape of the mold cavity 52. The bottom shape of the mold cavity 52 may be other than a hemisphere. For example, when it is desired to make the area of the contact surface as small as possible, the contact surface may be sharpened (even in this case, since it is ice, it smoothly moves on the substrate A so that the substrate A is not damaged). On the other hand, when it is desired to increase the area of the contact surface, it may be a flat bottom surface.

When the shaping is finished, the heating block 51 is lowered and separated from the core material 21 as shown in FIG. Thereafter, the heating block 51 is returned to the avoidance position (the position shown in FIG. 7A) that does not collide with the turntable 12.
By incorporating the above shaping operation at the time of laser scribing (incorporated after FIG. 4A), the end face 21a on which the ice layer having a fixed shape is always in contact with the substrate A, so that the processing accuracy is further improved. Can be improved.

(Embodiment 3)
FIG. 8 is an overall configuration diagram of the substrate processing apparatus LS3 according to the third embodiment of the present invention. FIG. 9 is a partial configuration diagram showing the substrate cooling mechanism 20a in the substrate processing apparatus LS3. 8 and 9, the same components as those of the substrate processing apparatus LS1 (FIG. 1) are denoted by the same reference numerals, and the description thereof is omitted.

  In the substrate processing apparatus LS1 of the first embodiment and the substrate processing apparatus LS2 of the second embodiment, the substrate cooling mechanism 20 is solidified by cooling the cooling medium sprayed from the nozzles 27 to form a solid phase refrigerant. On the other hand, in the substrate processing apparatus LS3, a solid phase refrigerant for replacement is separately prepared and replaced with a new solid phase refrigerant when the used solid phase refrigerant is consumed. Specifically, columnar ice is formed and prepared by a separate refrigeration apparatus, and is replaced when necessary.

Therefore, the substrate processing apparatus LS3 includes a substrate cooling mechanism 20a including a support member 61 that can attach and remove the solid-phase refrigerant CL.
The support member 61 will be described. The support member 61 has a cylindrical housing 62 and the upper end of the ice (solid-phase refrigerant CL) shown in the figure with the lower end of the ice (solid-phase refrigerant CL) previously shaped into a columnar shape facing the substrate A. A grip part 63 that is fixed by a clip that is not used, a lift mechanism 64 for the grip part that lifts and lowers the grip part 63 in the housing 62, and a guide 65 that directs ice (solid-phase refrigerant CL) vertically downward. Ice (solid-phase refrigerant CL) is fixed by a clip of the gripping portion 63 by being inserted along the guide 65 from below the housing. The lifting mechanism 64 for the gripping portion is gradually lowered according to the amount of ice consumption, so that the lower end surface of the ice (solid phase refrigerant CL) is always exposed to the outside of the housing 62. The raising / lowering operation of the raising / lowering mechanism 64 may be performed in conjunction with counting the number of times the substrate A is cooled.

The lifting rod 24 is fixed to the upper surface of the housing 62. The lifting rod 24 is connected to a pressing mechanism 25 for bringing the support member 61 into contact with the substrate A. The pressing mechanism 25 moves the support member 61 up and down by moving the lifting rod 24 up and down by a lifting mechanism 26 composed of a coil spring and a solenoid valve (not shown). When the support member 61 is lowered and the ice (solid-phase refrigerant CL) is in contact with the substrate A, the solid-phase refrigerant CL is adjusted so as to press the substrate A with an appropriate force by the coil spring.
Regarding the control system of the substrate processing apparatus LS3, the substrate cooling mechanism driving unit 32 drives the lifting operation of the lifting mechanism 64 for the gripping unit. Other controls are the same as those of the substrate processing apparatus LS1. Note that the replacement of ice (solid-phase refrigerant CL) can be automated by the robot hand, but in this case, the substrate cooling mechanism driving unit 32 also controls the replacement operation by the robot hand.

  Processing operations by the substrate processing apparatus LS3 will be described. The first ice (solid-phase refrigerant CL) is attached to the support member 61, and the beam spot scan and the ice (solid-phase refrigerant CL) scan are executed in the same manner as in the first embodiment. A crack due to a temperature difference is formed on the substrate. As the first ice (solid-phase refrigerant CL) is consumed, the gripping part lifting mechanism 64 is operated to lower the ice (solid-phase refrigerant CL). When the initial ice (solid-phase refrigerant CL) is almost gone, the remaining ice is extracted and replaced with new ice (solid-phase refrigerant CL). In this way, laser scribing is continued.

  INDUSTRIAL APPLICABILITY The present invention can be used for a laser processing apparatus that can accurately form a crack along a planned processing line on a brittle material substrate such as a glass substrate.

Claims (10)

A laser irradiation mechanism for forming a beam spot on a brittle material substrate for local heating by irradiation with a laser beam;
A substrate cooling mechanism for forming a cooling region for locally cooling the substrate;
A scanning mechanism that relatively moves the beam spot and the cooling region in the order of the beam spot and the cooling region along a processing scheduled line set on the substrate;
A laser processing apparatus for a brittle material substrate that forms a crack due to thermal stress along the planned processing line by passing a cooling region immediately after a beam spot has passed,
The substrate cooling mechanism is composed of a solid-phase refrigerant that is solidified by cooling a refrigerant material that becomes a gas or a liquid at room temperature, and a pressing mechanism that brings the solid-phase refrigerant into contact with the substrate. Laser processing equipment.   The laser processing apparatus according to claim 1, wherein any one of ice, solid state alcohol, and dry ice is used as the solid phase refrigerant.   The substrate cooling mechanism further includes a refrigerant supply unit that supplies the refrigerant material, and a solidification unit that cools the supplied refrigerant material to a temperature at which the refrigerant material is solidified to be a solid phase refrigerant. The laser processing apparatus according to claim 1 or 2.   The refrigerant supply unit includes a nozzle that injects the refrigerant material, and the solidification unit is arranged so that an end surface facing the substrate is provided and the refrigerant material injected from the nozzle adheres to the end surface. The laser processing apparatus according to claim 3, further comprising: a core material that cools the end surface of the core material to a temperature equal to or lower than a temperature at which the refrigerant material is solidified.   3. The laser according to claim 1, wherein the pressing mechanism includes a support member that detachably supports the solid-phase refrigerant in a state where one end surface of the solid-phase refrigerant is opposed to the substrate. Processing equipment.   The laser processing apparatus according to claim 1, wherein the substrate cooling mechanism further includes a shaping mechanism that shapes a contact surface of the solid-phase refrigerant that contacts the substrate with respect to the solid-phase refrigerant. The substrate is heated by scanning a beam spot formed by laser beam irradiation along a scheduled processing line set on a brittle material substrate, and then cooled immediately after the beam spot passes to the planned processing line. A method of laser processing a brittle material substrate that forms a crack due to thermal stress along
The method for laser processing a brittle material substrate is characterized in that the substrate is cooled by bringing a solid-phase refrigerant solidified by cooling a refrigerant material that becomes a gas or a liquid at room temperature into contact with the substrate.   The laser processing method according to claim 7, wherein ice, solid alcohol, or dry ice is used as the solid-phase refrigerant.   The laser processing method according to claim 7, wherein the solid-phase refrigerant contains a surfactant as an additive.   The laser processing method according to claim 7, wherein the solid-phase refrigerant contains a cleaning agent as an additive.

Images