JP5258024B2 - Laser cutting method and workpiece - Google Patents

Description

  The present invention relates to a laser cutting method and an object to be cut for cutting a substrate such as thin glass used for a thin liquid crystal panel, for example.

  2. Description of the Related Art In recent years, there has been a rapid movement toward thinning displays typified by liquid crystal and organic EL. With this trend, development of processing technology suitable for thin displays has been actively conducted. The glass substrate is thinned by a method such as chemical etching. On the other hand, a method of cutting a glass substrate is generally a method of thinning after cutting into a panel size before etching the glass substrate because of problems such as yield and processing speed. However, if thin glass can be cut with high yield and high speed, it is very advantageous in terms of the process.

  Conventionally, as a method for laser cutting a glass substrate, as disclosed in JP-A-11-104869, a groove is formed in advance by chemical etching on a breaking line, and then laser irradiation is performed, As disclosed in Japanese Patent No. 35710, the surface of a workpiece is modified with a first laser beam and the modified portion is irradiated with a second laser beam for processing, or disclosed in Japanese Patent Laid-Open No. 2007-238438. As described above, when irradiating the laser beam along the planned cutting line of the glass substrate, a method of changing the cutting condition from the start to the end of the cutting, and further, this report describes the upper and lower sides of the glass substrate bonding panel. In the same manner, a method for cutting a panel by irradiating two lasers is described. Each of these methods utilizes a phenomenon in which thermal stress generated by a temperature gradient of a glass substrate caused by laser irradiation causes a crack in the thickness direction of the substrate.

  However, if the thickness of the glass substrate is reduced, this method simply makes it difficult for cracks to propagate in the thickness direction.Therefore, cracks remain at the edge of the cut out substrate after cleaving, or the substrate breaks during cleaving. Or cut with good yield. Furthermore, since these methods utilize the progress of cracks, they cannot be processed into complex shapes or arbitrary shapes.

In addition, as a method of cutting glass by laser pulse oscillation, there is a report on laser cutting of soda glass disclosed in Japanese Patent Laid-Open No. 7-16769. This is the thickness of the substrate when scribing and cutting. The scribing depth is adjusted below and finally the stress is applied to divide the substrate along the scribing hole, so it cannot be applied to thin glass, and it is difficult to process into any shape. is there.
JP-A-11-104869 JP 2006-35710 A JP 2007-238438 A Japanese Patent Laid-Open No. 7-16769

  As described above, in the conventional laser cutting method, it has been impossible to laser-cut a substrate or a panel such as thin glass into an arbitrary shape at high speed without causing a crack.

  In view of the above problems, the object of the present invention is to efficiently produce a thin glass, a film-laminated substrate, or a panel obtained by laminating these substrates in an arbitrary shape without causing defects such as cracks. The present invention proposes a laser cutting method and an object to be cut that can be cut into two pieces.

  In order to solve the above-described problems and achieve the object, the present invention is configured as follows.

The invention according to claim 1 is a method of cutting a glass substrate or a composite substrate supported by laminating a film on the glass substrate by irradiating with a pulsed pulse laser.
A hole penetrating the glass substrate by one pulse laser irradiation, and a hole processed by a continuous pulse laser is irradiated and cut at a position separated by a distance greater than the hole diameter,
Furthermore, in order to cut out an arbitrary processed shape, the periphery of the processed shape is circulated while being irradiated with a plurality of times of pulse laser, and a hole is made and cut.
Holes to be machined in the n-th round are characterized in that all holes around the machined shape are finally connected and cut by irradiating a pulse laser between the holes that have been bored in the previous round. This is a laser cutting method.

  The invention according to claim 2 is the laser cutting method according to claim 1, wherein the pulse laser is a carbon dioxide gas laser.

The invention according to claim 3 is a panel configured by stacking and bonding two sheets of the glass substrate or the composite substrate and the film substrate, the glass substrate or the composite substrate in combination,
For the panel,
The laser cutting method according to claim 1 or 2, wherein the panel is cut by irradiating the pulse laser.

  According to a fourth aspect of the invention, the glass substrate, the composite substrate, or the film substrate is a substrate for holding liquid crystal, according to any one of the first to third aspects. This is a laser cutting method.

  According to a fifth aspect of the present invention, an XY stage that can move at an arbitrary speed and at an arbitrary distance is used to irradiate the arbitrary position with a pulse laser. It is a laser cutting method given in any 1 paragraph.

  A sixth aspect of the present invention is the laser cutting method according to any one of the first to fifth aspects, wherein the glass substrate has a thickness of 200 μm or less.

  According to a seventh aspect of the present invention, in the laser according to any one of the first to sixth aspects, the processing position accuracy of irradiating the arbitrary position with a pulse laser is ± 10 μm or less. Cutting method.

  According to an eighth aspect of the present invention, the cut surface of the workpiece after being cut by the laser cutting method according to any one of the first to seventh aspects has a shape of a hole processed by a pulse laser. It is a to-be-cut object characterized by having a continuous periodic pattern shape.

  With the above configuration, the present invention has the following effects.

  In the first aspect of the present invention, the holes to be machined are irradiated with a pulse laser between the holes that have been formed so far, so that all the holes around the machined shape are finally connected and cut. Without causing defects such as cracks, it is possible to efficiently cut a thin glass, a film-laminated substrate, or a panel obtained by laminating these substrates into an arbitrary shape. In addition, since the laser ON and OFF times can be controlled by using a pulse laser, it is possible to cut without applying excessive heat to the substrate. Moreover, a high peak output can be easily obtained with a pulse laser, and cutting can be performed without causing an extra thermal effect.

  In the second aspect of the present invention, the pulse laser is a carbon dioxide gas laser, which can easily obtain a high output and has a high absorptance in glass and resin, so that it can be easily melted and cut by heat.

  In the invention according to claim 3, a panel is constituted by combining two glass substrates or composite substrates and a film substrate, glass substrate or composite substrate and bonding them together, and the panel is irradiated with a pulse laser. Can be cut off.

  In the invention according to claim 4, the glass substrate, the composite substrate, and the film substrate are substrates for holding the liquid crystal, and are easily melted and cut by heat.

  In the invention described in claim 5, by using an XY stage capable of moving at an arbitrary speed and at an arbitrary distance in order to irradiate a pulse laser at an arbitrary position, it can be cut into an arbitrary shape at a high speed. .

  In the invention described in claim 6, the glass substrate has a thickness of 200 μm or less and can be easily melted and cut by the heat of the pulse laser.

  In the invention described in claim 7, the processing position accuracy of irradiating a pulse laser to an arbitrary position is ± 10 μm or less, and cutting can be performed with high accuracy.

  In the invention described in claim 8, the cut surface of the object to be cut after being cut by the laser cutting method has a periodic pattern shape in which the shapes of the holes processed by the pulse laser are continuous, and can be efficiently formed into an arbitrary shape. Can be cut.

  Embodiments of a laser cutting method and an object to be cut according to the present invention will be described below. The embodiment of the present invention shows the most preferable mode of the present invention, and the present invention is not limited to this.

  As shown in FIGS. 1A and 1B, the present invention irradiates a pulsed laser 4 that pulsates a glass substrate 1 or a composite substrate 3 that is supported by bonding a film 2 to the glass substrate 1. It is a method of cutting by doing.

  As shown in FIG. 2, the hole 1 a penetrating the glass substrate 1 is formed by one irradiation of the pulse laser 4, and the hole 1 a processed by the continuous pulse laser 4 has a distance L equal to or larger than the hole diameter D. It is cut by irradiating a position separated from each other.

  Further, in order to cut out an arbitrary processing shape, as shown in FIG. 3, the periphery of the processing shape is circulated while irradiating a plurality of times of the pulse laser 4 to cut the hole 1a, and the processing is performed at the n-th turn. The holes 1a to be formed are irradiated with the pulse laser 4 between the holes 1a that have been opened so far, so that all the holes 1a around the processed shape are finally connected and cut.

  For example, when a shape such as a circle or a rectangle is cut out, the first round hole 1a, the second round hole 1a,..., The nth round hole 1a are sequentially formed. , N-1 rounds are formed between the holes 1a that have already been opened, and finally the holes 1a are connected to form an arbitrary shape.

  By using the pulse laser 4, the laser ON and OFF times can be controlled, so that it is possible to cut without applying excessive heat to the substrate. Further, the pulse laser 4 can easily obtain a high peak output, and the peak output is high, so that the pulse laser 4 can be cut without causing an excessive heat effect.

  In addition, it is preferable to use a carbon dioxide laser as the pulse laser 4. By using a carbon dioxide laser, a high output can be easily obtained, and the glass or resin of the material can have a high absorption rate. It's easy to do.

  Further, the processing position accuracy of irradiating the pulse laser 4 to an arbitrary position is ± 10 μm or less, and cutting can be performed with high accuracy.

  Further, the glass substrate 1 has a thickness of 200 μm or less and can be easily melted and cut by the heat of the pulse laser 4.

  In this laser cutting method, as shown in FIG. 1, it is preferable to use an XY stage 10 that can move at an arbitrary speed and at an arbitrary distance in order to irradiate a pulse laser 4 at an arbitrary position. By using it, it can be cut into an arbitrary shape at high speed.

  In this laser cutting method, the panel 20 is cut by irradiating the panel 20 with the pulsed laser 4 as shown in FIG. As shown in FIG. 4, the panel 20 is configured by combining two glass substrates 1 or a composite substrate 3 and a film substrate 21, a glass substrate 1 or a composite substrate 3 and bonding them together. The panel 20 may be a liquid crystal panel in which a liquid crystal layer, an alignment film, an electrode, and the like are formed between two substrates. The glass substrate 1, the composite substrate 3, and the film substrate 21 are substrates for holding liquid crystal, and can be easily melted and cut by heat by irradiating the pulse laser 4 to the substrate or panel.

  In this way, the hole 1a to be machined is irradiated with the pulse laser 4 between the holes 1a that have been drilled so far, so that all the holes 1a around the machined shape are finally connected, cut, and cracked. The thin glass, the film-laminated substrate, or the panel obtained by laminating these substrates can be efficiently cut into any shape without causing problems such as these.

  The to-be-cut object 30 of this invention is cut | disconnected by the laser cutting method, and the cut end 30a of the to-be-cut object 30 after this cutting | disconnection is a continuous form of the shape of the hole 1a processed by the pulse laser 4, as shown in FIG. Therefore, it can be cut into an arbitrary shape efficiently.

Example 1
Embodiments of the present invention will be described below with reference to the drawings. FIG. 6 is an overall view of a laser processing apparatus to which the laser cutting method of the present invention is applied. In FIG. 6, 41 is a carbon dioxide laser oscillator, 42 is an external optical unit having a reflecting mirror 42a and a condenser lens 42b, 43 is an assist gas, 44 is a workpiece, 45 is an XY stage, and 46 is numerically controlled (NC). Device.

  The workpiece 44 is a glass substrate having a thickness of 200 μm or less, a composite substrate in which a film is bonded to and supported by the glass substrate, or a panel formed by stacking and bonding two of these substrates.

  The operation of the XY stage 45 is controlled by a numerical control (NC) device 46, thereby guaranteeing a machining position accuracy of ± 10 μm.

  The carbon dioxide laser oscillator 41 irradiates the pulse laser 4 with pulse oscillation, and focuses the light through the external optical system unit 42 so as to focus on the surface of the workpiece 44. At this time, according to the program set by the numerical control (NC) device 46, the XY stage 45 is moved and the workpiece 44 is cut. At this time, the assist gas 43 is blown out from the nozzle tip toward the cutting portion. At this time, exhausting from the bottom of the XY stage 45 and the peripheral portion of the nozzle prevents contamination of the condenser lens 42b.

  Using the laser processing apparatus having the above configuration, a substrate in which OA10 glass was thinned by chemical etching to 30 to 300 μm was used as the workpiece 1.

  A pulse carbon dioxide laser with a laser spot diameter of 100 μm and an output of 225 W was irradiated for 60 μs to form a through hole in the workpiece 1, and then the next through hole was formed at a position shifted by 120 μm.

  In order to cut out a square object having a side of 40 mm, irradiation was performed while circulating a pulse laser around the object to be cut four times.

  At this time, with respect to the position of the hole in the first round, the second round was shifted by 60 μm with respect to the cutting progress direction, the first through hole was opened, and then the through holes were made at a pitch of 120 μm as in the first round. In the third round, the first through holes were made by shifting by 30 μm from the position of the first round holes, and then through holes were similarly made at a pitch of 120 μm. In the 4th round, the first through hole was made by shifting by 90 μm from the position of the 1st round hole, and then through holes were similarly made at a pitch of 120 μm. In this way, an object to be cut 1 was obtained. The moving speed of the XY stage at this time was 1000 mm / min.

  When the cut end of the workpiece 1 was focused on the surface from the top and observed with a microscope at a magnification of 450 times, no cracks of 10 μm or more were observed as shown in FIG.

  The shape of the cut part of the workpiece 1 is shown in FIG. It was recognized that the cut end portion of the workpiece 1 has a continuous arc shape due to the continuous laser spot shape (circular shape).

(Example 2)
A laser processing apparatus similar to that in Example 1 is used, and a composite substrate obtained by bonding the object 1 used in Example 1 to a 100 μm-thick plastic film and an adhesive is used as object 2. This workpiece 2 was processed under the same conditions as in Example 1 except that a pulse carbon dioxide laser with an output of 225 W was irradiated for 75 μs.

  When the object 2 was observed with a microscope in the same manner as in Example 1, no cracks of 10 μm or more were observed.

  As for the shape of the cut part of the workpiece 2, a periodic pattern was recognized as in FIG. 8.

  (Example 3) Using the same laser processing apparatus as in Example 1, a composite substrate similar to that in Example 2 was processed under the same processing conditions as in Example 2 except that the movement speed of the XY stage was set to 2000 mm / min. did. The processed sample is defined as an object 3 to be cut.

  When the object 3 was observed with a microscope in the same manner as in Example 1, no cracks of 10 μm or more were observed.

  As for the shape of the cut portion of the workpiece 3, a periodic pattern was recognized as in FIG. 8.

Example 4
Using the same laser processing apparatus as in Example 1, a composite substrate similar to that in Example 2 was processed under the same processing conditions as in Example 2 except that the moving speed of the XY stage was set to 3000 mm / min. The processed sample is defined as a workpiece 4.

  When the object 4 was observed with a microscope in the same manner as in Example 1, no cracks of 10 μm or more were observed.

  As for the shape of the cut portion of the workpiece 4, a periodic pattern was recognized as in FIG. 8.

(Example 5)
As shown in FIG. 9, a sample processed into an alphabetic T shape is defined as an object to be cut 5 using the same laser processing apparatus as in Example 1 and the same composite substrate and processing conditions as in Example 2.

  When the object 5 was observed with a microscope in the same manner as in Example 1, no cracks of 10 μm or more were observed.

  As for the shape of the cut portion of the workpiece 5, a periodic pattern was recognized as in FIG. 2.

(Example 6)
As shown in FIG. 10, a sample processed into an R-shape of the alphabet is used as an object to be cut 6 as shown in FIG. 10 using the same laser processing apparatus as in Example 1 and the same composite substrate and processing conditions as in Example 2.

  When the object 6 was observed with a microscope in the same manner as in Example 1, no cracks of 10 μm or more were observed.

  As for the shape of the cut portion of the workpiece 6, a periodic pattern was recognized as in FIG. 2.

(Example 7)
Using the same laser processing apparatus as in Example 1, two of the objects to be cut 2 used in Example 2 were bonded together with a sealant through a 5 μm spacer, and an ITO electrode pattern and polyimide were formed on the inside of the substrate. A 40 mm square cell (range outside the sealant) into which the alignment film and liquid crystal were injected was defined as the object 7 to be cut.

  The workpiece 2 was processed under the same conditions as in Example 1 except that a pulse carbon dioxide laser with an output of 225 W was irradiated for 100 μs.

  When the cut object 7 was observed with a microscope on the upper and lower end portions of the cell in the same manner as in Example 1, no cracks of 10 μm or more were observed on the glass surface.

  As for the shape of the cut portion of the workpiece 7, a periodic pattern was recognized as in FIG. 2.

(Comparative Example 1)
Using the same laser processing apparatus as in Example 1, the object to be cut used in Example 2 was irradiated with a pulse carbon dioxide laser with a laser spot diameter of 100 μm and an output of 225 W for 75 μs, and a through hole was made in the object to be cut. The next through hole was opened at a position shifted by 30 μm. In order to cut out a square cut object having a side of 40 mm, the cut object 8 was obtained by irradiating with a pulse laser around the cut object once round. The moving speed of the XY stage at this time was 250 mm / min.

  When the cut object 8 was observed with a microscope at the upper and lower end portions of the cell in the same manner as in Example 1, an infinite number of cracks of 100 μm or more were observed on the glass surface, as shown in FIG.

  The periodic pattern of the shape of the cut portion of the workpiece 8 was not recognized as in FIG.

(Comparative Example 2)
Using the same laser processing apparatus as in Example 1, the object to be cut used in Example 2 was irradiated with a pulse carbon dioxide laser with a laser spot diameter of 100 μm and an output of 225 W for 75 μs, and a through hole was made in the object to be cut. The next through hole was opened at a position shifted by 30 μm. In order to cut out a square cut object having a side of 40 mm, the cut object 9 was obtained by irradiating a pulse laser around the cut object once around. The moving speed of the XY stage at this time was set to 125 mm / min.

  When the upper and lower surface ends of the cell 9 were observed with a microscope in the same manner as in Example 1, countless cracks of 100 μm or more were observed on the glass surface.

  The periodic pattern of the shape of the cut portion of the workpiece 9 was not recognized as in FIG.

  The present invention can be applied to a laser cutting method for cutting a substrate such as a thin glass used for a thin liquid crystal panel or the like, and an object to be cut, and without causing defects such as cracks, a thin glass and a film bonded substrate. Or the panel which bonded these board | substrates can be efficiently cut | disconnected in arbitrary shapes.

It is a figure explaining the laser cutting method of this invention. It is a figure explaining irradiation of a pulse laser. It is a figure explaining the cutting | disconnection by irradiation of a pulse laser. It is a figure explaining the structure of a panel. It is a figure which shows the cutting state of a to-be-cut object. 1 is an overall view of a laser processing apparatus. It is a figure which shows the cutting state of a to-be-cut object. It is a figure which shows the periodic pattern of a cutting | disconnection edge part. It is a figure which shows the to-be-cut object processed into the T shape of the alphabet. It is a figure which shows the to-be-cut object processed into the R shape of the alphabet. It is a figure which shows the cutting state of the to-be-cut object of a comparative example.

Explanation of symbols

1 Glass substrate
1a hole 2 film 3 composite substrate 4 pulse laser 10 XY stage 20 panel 21 film substrate 30 workpiece 41 carbon dioxide laser oscillator 42 external optical unit 43 assist gas 44 workpiece 45 XY stage 46 numerical control (NC) device

Claims (8)

A method of cutting a glass substrate or a composite substrate supported by laminating a film on the glass substrate by irradiating a pulsed pulsed laser,
A hole penetrating the glass substrate by one pulse laser irradiation, and a hole processed by a continuous pulse laser is irradiated and cut at a position separated by a distance greater than the hole diameter,
Furthermore, in order to cut out an arbitrary processed shape, the periphery of the processed shape is circulated while being irradiated with a plurality of times of pulse laser, and a hole is made and cut.
Holes to be machined in the n-th round are characterized in that all holes around the machined shape are finally connected and cut by irradiating a pulse laser between the holes that have been bored in the previous round. Laser cutting method.   The laser cutting method according to claim 1, wherein the pulse laser is a carbon dioxide laser. The glass substrate or the composite substrate and the film substrate, the glass substrate or the composite substrate is combined to form a panel by stacking and bonding two sheets,
For the panel,
The laser cutting method according to claim 1, wherein the panel is cut by irradiating the pulse laser.   The laser cutting method according to any one of claims 1 to 3, wherein the glass substrate, the composite substrate, and the film substrate are substrates for holding liquid crystal.   The laser cutting according to any one of claims 1 to 4, wherein an XY stage capable of moving at an arbitrary speed and at an arbitrary distance is used to irradiate the arbitrary position with a pulse laser. Method.   The laser cutting method according to claim 1, wherein the glass substrate has a thickness of 200 μm or less.   The laser cutting method according to any one of claims 1 to 6, wherein a processing position accuracy of irradiating the arbitrary position with a pulsed laser is ± 10 µm or less. The cut surface of the object to be cut after being cut by the laser cutting method according to any one of claims 1 to 7 has a periodic pattern shape in which the shapes of holes to be processed by a pulse laser are continuous. A workpiece to be cut.