JP5437333B2 - Glass substrate scribing method and processing apparatus - Google Patents

Description

  The present invention relates to a glass substrate scribing method, and more particularly to a glass substrate scribing method for scribing tempered glass having a tempered layer having a compressive stress on its surface along a scribe line. Moreover, it is related with the processing apparatus which scribes tempered glass.

  As a method of forming a scribe groove for dividing a glass substrate, there is a method of forming a scribe groove using a laser beam. In this case, laser light is irradiated along the scribe line, and a part of the substrate is melted and evaporated to form a scribe groove. However, in this method, a part of the dissolved and evaporated substrate may adhere to the surface of the substrate, which may be accompanied by deterioration of quality. In addition, the scar formed in the melted and evaporated part causes a reduction in the strength of the substrate end face.

  Therefore, as another method of forming the scribe groove, there is a method as shown in Patent Document 1 or 2. Here, an initial crack is formed at a location that becomes the starting point of the scribe groove of the glass substrate, and the initial crack is irradiated with laser light. As a result, thermal stress is generated in the laser irradiation portion, and the crack progresses to form a scribe groove.

  Further, in the method of forming a scribe groove by irradiating a laser beam, the scribe groove has a tendency to deepen at the peripheral edge of the glass substrate. If the glass substrate is divided along the scribe groove in this state, there arises a problem that the quality of the divided section is deteriorated and a problem that the scribe groove is not formed straight.

  Therefore, Patent Document 3 discloses a laser scribing method in which a region where no scribe groove is formed is formed at the end of a scribe line. According to this method, it is described that the quality of a section after division at the terminal portion of the glass substrate can be improved without complicated control.

Japanese Patent Laid-Open No. 3-489 JP-A-9-1370 Republished patent WO2007 / 094348

  By the way, in the recent FPD (flat panel display) industry, since the strength of the substrate end face is regarded as important, chemically tempered glass having a tempered layer formed on the surface is mainly used as a glass substrate. This chemically tempered glass has a layer (strengthening layer) whose surface is given compressive stress by ion exchange treatment, and tensile stress exists inside. Such chemically tempered glass has recently been used for a cover glass such as a touch panel in which end face strength is particularly required.

  Among the tempered glasses, the present inventor has recently developed a scribe groove by using a laser scribing method, particularly in a tempered glass having a high surface, and mainly from the end of the scribe groove to the scribe groove. Experiments have found that deep cracks propagate along and are naturally divided. Here, the natural division is a phenomenon in which the glass substrate is divided along the scribe groove without performing the division step after the scribe groove is formed.

  Natural division is considered to be caused by deep cracks in the scribe groove at the peripheral edge of the glass substrate, and this deep crack is considered to develop along the scribe groove. And the following reason can consider that the crack of a scribe groove | channel becomes deep in the peripheral part of a glass substrate.

  -Since the end surface is not restrained in the terminal part of the glass substrate in which the scribe groove is formed, both sides of the scribe groove are easily opened.

  -In the terminal part of the glass substrate in which the scribe groove is formed, there is no place for heat to escape from there, and heat is accumulated in the terminal part.

  When natural separation occurs due to the above-described causes, it becomes difficult to process the subsequent process.

  In view of this, it is conceivable to shield the laser light by attaching an aluminum tape to the end of the planned scribe line so that the scribe groove is not formed on the peripheral edge of the glass substrate. However, this method is not practical from the viewpoint of productivity.

  Further, it is conceivable that the scribe groove does not reach the end of the scribe line by controlling the laser light irradiation so that the heat treatment and the cooling treatment are not performed on the peripheral portion of the glass substrate. . However, with this method, it is difficult to stop the scribe groove at a desired position, and there is no stability.

  An object of the present invention is to form a desired scribe groove easily and stably in a tempered glass and prevent natural division.

A scribing method for a glass substrate according to a first invention is a method of scribing glass having a reinforced layer having a compressive stress on a surface along a plurality of scribe lines that are orthogonal to each other , and includes the following steps. doing.

First step: Glass is placed on a table having a plurality of suction holes for holding a substrate, and the entire outer peripheral edge of the glass is sucked with a stronger suction pressure than other regions .

  Second step: An initial crack is formed on the surface of the glass.

Third step: The surface of the glass is heated by irradiating a laser beam, the heated region is cooled, and cracks are propagated along a plurality of scribe lines orthogonal to each other to form scribe grooves.

  Here, the glass to be processed is first placed on a table. The table is provided with a plurality of suction holes, and the glass is sucked through the suction holes and held at a predetermined position of the table. At this time, the glass end portion on the terminal side of the scribe line is sucked and held with a stronger force than other regions. Then, after the initial crack is formed, the glass surface is irradiated with laser light and heated, and the heated region is cooled. By this heating and cooling treatment, the initial crack propagates along the scribe line and a scribe groove is formed.

  In this method, the glass end portion on the terminal side of the scheduled scribe line is held on the table with a stronger suction force. Therefore, the glass end portion is not easily deformed when the heating and cooling processes are performed. For this reason, it becomes difficult to open a crack in a glass edge part, it can suppress that a deep crack is formed, and a natural division can be avoided. Further, a complicated operation such as applying an aluminum tape is unnecessary, and the formation of the scribe groove can be stably stopped at a desired position.

The glass substrate processing apparatus according to the second invention is an apparatus for scribing glass having a reinforced layer with compressive stress on the surface along a scribe line, a table, an irradiation unit, a cooling unit, A moving means and an adsorption pressure control unit are provided. The table has a plurality of suction holes, and sucks and holds the glass placed on the surface. The irradiation unit irradiates the glass with a laser beam. The cooling unit cools the region heated by the irradiation unit. The moving means relatively moves the irradiation unit and the cooling unit along a scheduled scribe line set in the glass. The adsorption pressure control unit controls the adsorption pressure at the table so that at least the end portion of the glass at the end of the scribe line is stronger than the central portion.

The glass substrate processing apparatus according to a third aspect of the present invention is the processing apparatus of the second aspect, wherein the adsorption pressure control unit uses the adsorption pressure in the table to determine the end of the glass scribe line on the start end side and the end end side. Control is performed so that the portion is stronger than the central portion.

For example, when the groove depth of the initial crack is deep, in the scribe groove forming process, the deep crack progresses from the initial crack toward the direction opposite to the scanning direction of heating and cooling, that is, toward the glass edge, May cause natural fragmentation.

Therefore, in the third aspect of the invention, in addition to the end portion on the end side of the scheduled scribe line, the end portion on the start end side is held with a strong suction force. Thereby, the deformation | transformation in the glass edge part at the time of formation of a scribe groove | channel is suppressed, and it can also suppress that a crack progresses toward the start end side of a scribe plan line. For this reason, natural division from the start end side can be avoided.

A glass substrate processing apparatus according to a fourth aspect of the present invention is the processing apparatus of the second aspect, wherein the scribe grooves are formed along a plurality of scribe lines that are orthogonal to each other. And an adsorption pressure control part controls all the outer periphery edge parts of glass so that it becomes strong compared with another area | region.

Here, in the case of performing cross scribing, it is possible to suppress the formation of deep cracks at the glass edge as in the case described above, and natural fragmentation can be avoided.

  As described above, in the present invention, the progress of cracks can be stopped easily and stably before the end portion of the planned scribe line with respect to the glass having the reinforcing layer having a compressive stress on the surface. Accordingly, it is possible to prevent the glass from being naturally divided when the scribe groove is formed in the glass.

The schematic block diagram of the apparatus for enforcing the scribe method by one Embodiment of this invention. The figure which shows the relationship between the board | substrate adsorption pressure to a table, and a scribe process.

[Device configuration]
FIG. 1 is a diagram showing a schematic configuration of a scribing apparatus for carrying out a method according to an embodiment of the present invention. The scribe device 1 is a device for dividing a mother glass substrate into a plurality of unit substrates used for an FPD (flat panel display), for example. As the glass substrate here, chemically strengthened glass having a tempered layer formed on the surface is mainly used. As described above, this chemically strengthened glass has a tempered layer having a compressive stress on the surface by an ion exchange treatment.

  The scribing device 1 includes a table 2 on which a glass substrate G is placed, a cutter wheel 3, a laser irradiation unit 4, a cooling unit 5, a drive mechanism 6, two suction pumps 7a and 7b, and a control unit 8. And.

  The table 2 is formed with a plurality of through-holes 10 whose upper portions are released from the table surface. The through-hole 10a formed in the position corresponding to the outer peripheral edge part of the glass substrate G among the several through-holes 10 is connected to the 1st suction pump 7a via the 1st channel | path 11 shown as a continuous line. Further, the plurality of through holes 10b other than the through hole 10a are connected to the second suction pump 7b via the second passage 12 indicated by a one-dot chain line.

  The cutter wheel 3 is a tool for forming an initial crack serving as a starting point for scribing at the end of the glass substrate G. This cutter wheel 3 mainly has a holder and a scribing wheel supported by the holder.

The laser irradiation unit 4 includes a laser oscillator (for example, a CO ₂ laser) that irradiates a laser beam, and irradiates the laser beam as a beam spot on the glass substrate G through an optical system. The cooling unit 5 forms a cooling spot by injecting a coolant (for example, water and air, helium gas) supplied from a coolant source (not shown) through a nozzle.

  The drive mechanism 6 is a mechanism that moves the cutter wheel 3, the laser irradiation unit 4, and the cooling unit 5 along the rail 14. By this driving mechanism 6, the cutter wheel 3, the laser irradiation unit 4, and the cooling unit 5 are moved along a scheduled scribe line set on the glass substrate G.

  The control unit 8 controls the cutter wheel 3, the laser irradiation unit 4, the cooling unit 5, the drive mechanism 6, and the two suction pumps 7a and 7b. Specifically, the controller 8 controls the pressing force of the cutter wheel 3 on the glass substrate G, the laser output, the refrigerant injection amount, the driving speed (scanning speed), and the rotation speed (adsorption pressure) of the suction pumps 7a and 7b. Be controlled.

[Relationship between substrate adsorption pressure and scribe]
The scribing results are shown below when the laser output and the scanning speed are changed and the adsorption pressure is changed under the respective conditions. A summary of each experimental example is shown in FIG.

<Experimental example 1>
Adsorption pressure of glass substrate G to table 2 (kPa): 5, 10, 20
Laser output: 140W
Scanning speed: 190mm / s
In Experimental Example 1, scribing was possible at a low adsorption pressure of 5 kPa (indicated by “◯” in FIG. 2), but scribing was not possible at high adsorption pressures of 10 and 20 kPa (“×” in the figure). ”).

<Experimental example 2>
Adsorption pressure of glass substrate G to table 2 (kPa): 5, 10, 20
Laser output: 160W
Scanning speed: 230mm / s
In Experimental Example 2, scribing was possible at adsorption pressures of 5 and 10 kPa, but scribing was not possible at adsorption pressure of 20 kPa.

<Experimental example 3>
Adsorption pressure of glass substrate G to table 2 (kPa): 5, 10, 20
Laser output: 170W
Scanning speed: 250mm / s
In Experimental Example 3, scribing was possible at adsorption pressures of 5 and 10 kPa, but scribing was not possible at adsorption pressure of 20 kPa.

<Experimental example 4>
Adsorption pressure of glass substrate G to table 2 (kPa): 5, 10, 20
Laser output: 180W
Scanning speed: 260mm / s
In Experimental Example 4, scribing was possible at adsorption pressures of 5 and 10 kPa, but scribing was not possible at adsorption pressure of 20 kPa.

  As is clear from the above experimental examples, it is understood that when the adsorption pressure is increased, that is, the suction force is increased to suppress the deformation of the glass substrate during the formation of the scribe groove, the progress of the crack is stopped.

[Scribe method]
Based on the above knowledge, in this embodiment, a scribe groove | channel is formed with the following scribe methods.

  First, the glass substrate G to be processed is placed on the table 2. Then, the first suction pump 7 a and the second suction pump 7 b are driven to suck the glass substrate G onto the table 2. At this time, the control unit 8 controls the number of rotations of the suction pumps 7a and 7b so that the suction pressure by the first suction pump 7a is 20 kPa or more, and the suction pressure by the second suction pump 7b is 10 kPa or less. Control to be.

  Next, an initial crack serving as a starting point for scribing is formed at the end of the glass substrate G using the cutter wheel 3.

  Next, the laser beam is irradiated from the laser irradiation unit 4 to the glass substrate G. This laser beam is irradiated onto the glass substrate G as a beam spot. Then, the laser beam emitted from the laser irradiation unit 4 is scanned along the scribe line. The glass substrate G is heated to a temperature lower than the softening point of the glass substrate G by the beam spot. Further, the cooling spot is made to follow behind the moving direction of the beam spot.

  As described above, compressive stress is generated in the vicinity of the beam spot heated by the laser beam irradiation, but immediately after that, a cooling spot is formed by the injection of the refrigerant. Occurs. Due to this tensile stress, a vertical crack is formed along the scribe line from the initial crack formed at the end of the glass substrate G, and a desired scribe groove is formed.

  Here, in the step of forming the scribe groove, the start end portion and the end portion of the planned scribe line, that is, the end portion of the glass substrate G is held with a strong adsorption pressure (suction force). Therefore, the deformation of the glass substrate G due to the heating and cooling processes can be suppressed, and the progress of cracks can be suppressed. For this reason, it can suppress that a deep crack is formed in the edge part of the glass substrate G, and can prevent that a board | substrate is divided naturally.

[Feature]
In this embodiment, the end of the glass substrate is held on the table with a strong force to suppress deformation during processing, so that formation of deep cracks at the end of the glass substrate can be suppressed. For this reason, natural division of the substrate can be avoided.

  In addition, since the adsorption pressure of the substrate to the table is realized as a means for stopping the crack growth at the edge of the glass substrate, natural separation of the substrate can be avoided by a simple method.

[Other Embodiments]
The present invention is not limited to the above-described embodiments, and various changes or modifications can be made without departing from the scope of the present invention.

  (A) In the above embodiment, both the start side end and the end side end of the planned scribe line in the glass substrate are held on the table with a strong force, but the end side end of the planned scribe line You may make it hold | maintain only with strong force. Also, if the start side end is held with a strong force, the development of the initial crack is suppressed, and the scribe groove may not be formed, so the start side end is weak compared to the end side end, Further, it may be held stronger than the central portion.

  (B) In the above embodiment, the table is fixed and the laser irradiation unit and the like are moved. However, the laser irradiation unit and the like may be fixed and the table may be moved.

  (C) In the above embodiment, the cutter wheel for forming the initial crack is provided in the same apparatus together with the laser irradiation unit and the like. However, the cutter wheel may be provided in an apparatus different from the laser irradiation unit and the like. In this case, after forming an initial crack first, a glass substrate will be adsorb | sucked on a table. That is, the order of the initial crack forming step (second step) and the placing step of the glass substrate on the table (first step) is reversed from that of the above embodiment.

  (D) In the above-described embodiment, the cutter wheel is used to form the initial crack. However, the initial crack may be formed using laser processing such as laser ablation or modification. In this case, a laser irradiation mechanism using a UV laser or a green laser as a light source is provided for initial crack formation.

DESCRIPTION OF SYMBOLS 1 Scribe device 2 Table 3 Cutter wheel 4 Laser irradiation part 5 Cooling part 6 Drive mechanism 7a, 7b Suction pump 8 Control part 10 Through-hole
G Glass substrate

Claims (4)

A glass substrate scribing method for scribing a glass having a reinforcing layer having a compressive stress on a surface, along a plurality of scribing lines orthogonal to each other ,
A first step of placing the glass on a table having a plurality of suction holes for holding the substrate, and suctioning the entire outer peripheral edge of the glass with a stronger suction pressure than other regions ;
A second step of forming an initial crack on the surface of the glass;
A third step of irradiating and heating the surface of the glass with laser light, cooling the heated region, and developing a scribe groove by extending cracks along a plurality of scribe lines orthogonal to each other ;
A method for scribing a glass substrate. A glass substrate processing apparatus that scribes a glass having a reinforced layer having a compressive stress on a surface thereof along a scribe line.
A table having a plurality of suction holes and sucking and holding the glass placed on the surface;
An irradiation unit for irradiating the glass with a laser beam;
A cooling unit for cooling the region heated by the irradiation unit;
Moving means for relatively moving the irradiation unit and the cooling unit along a scribe line set in the glass;
An adsorption pressure control unit for controlling the adsorption pressure in the table so that at least the end of the scribe line on the terminal side of the glass is stronger than the central part;
A glass substrate processing apparatus comprising: The suction pressure control unit controls the suction pressure in the table so that the end portion on the start end side and the end portion on the end side of the glass scribe line are stronger than the center portion. The processing apparatus of the glass substrate of description. The glass substrate processing apparatus is a glass substrate processing apparatus that scribes along a plurality of scribe lines orthogonal to each other,
The glass substrate processing apparatus according to claim 2, wherein the adsorption pressure control unit controls the adsorption pressure of the table so that the entire outer peripheral edge of the glass is stronger than other regions.

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