JP2002103063A - Marking method for color filter substrate and color filter substrate marked thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a marking method for irradiating a color filter substrate under a constant laser irradiation condition while scanning a laser beam emitted from a laser light source to form a character, a figure or a symbol, in a later step. Not to occur. SOLUTION: In the marking method, a laser irradiation condition is a condition where a fibrous substance is not generated at an edge portion of a processing spot 7 which is processed when a laser beam is irradiated.
Specifically, the laser irradiation condition is such that the energy density is 10
A range in which a color filter film of 0 J / cm ² or less can be processed is set, and the area of the spot 6 of the laser beam and the area of the processed spot 7 are made equal. Other laser irradiation conditions are such that the area of the laser beam irradiation spot 6 is larger than the area of the processing spot 7 and the energy density at this time is 200 J /
cm ² or less, in which the color filter film can be processed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystal or PDP.
Characters, numbers, barcodes or 2 with information such as date and serial number on the color filter substrate of display devices such as panels
The present invention relates to a method of marking a dimensional code using a laser and a color filter substrate marked thereby.

[0002]

BACKGROUND ART characters with information such as the date, serial number, to the workpiece, numbers, as a marking device for marking a bar code or two-dimensional code, a carbon dioxide gas laser or Nd laser light source: YAG, Nd: YVO ₄ or the like Using a solid-state laser, emitting laser light from this laser light source,
By irradiating the workpiece with the laser beam while scanning by the scanning means, the surface of the workpiece undergoes a physical change (for example, peeling of the surface or surface layer, vaporization, burning,
It is generally known to perform marking by causing foaming, bulging, discoloration / bleaching, etc.). However, when the workpiece is a color filter substrate of a display device such as a liquid crystal or a PDP panel, there is a problem that when carbon dioxide is used as a laser light source, the glass substrate of the color filter substrate is damaged. In addition, Nd: YAG, Nd:
When using the solid-state laser of YVO ₄ or the like, a color filter film has a problem that the scattered particles are generated during marking.

In order to solve these problems, the present inventors have previously invented a device having a structure shown in FIG. 10 as a marking device for a color filter substrate (Japanese Patent Application No. 2000-2000).
No. 8374). In FIG. 10, 1 is a semiconductor laser used as a laser light source, 2 and 3 are scanner mirrors, 4 is a condenser lens, and 5 is a liquid crystal or a color filter substrate of a display device such as a PDP panel. The color filter substrate 5 generally has a color filter film 52 formed on the surface of a glass substrate 51 or a transparent resin substrate. This marking device is characterized in that particles are not generated at the time of marking by using a semiconductor laser as the laser light source 1.

Next, an operation for marking a two-dimensional code on the color filter substrate 5 using the marking device of FIG. 10 will be described. First, the scanner mirrors 2 and 3 rotate. After the positioning of the scanner mirrors 2 and 3, the scanner mirrors 2 and 3 stop. When the laser beam 8 is irradiated from the laser light source 1, the temperature of the irradiation spot 6 of the color filter film 52 rises and causes a physical change, so that the processing spot 7 is formed and becomes the first segment. Thereafter, the above operation is repeated until the final segment is formed, thereby forming a two-dimensional code. In the conventional marking method, the laser irradiation condition only needs to be higher than the energy density at which the processing spot 7 can be formed on the color filter film 52, and the upper limit is not particularly defined. Further, the conventional color filter substrate has been manufactured by the above-described marking device or marking method.

[0005]

However, when marking is performed on a color filter substrate of a liquid crystal display or a plasma display by a conventional marking method, particles are not generated at the time of marking. There was a problem that occurred. Electron microscope observation revealed that the cause of the particles was fibrous substances generated at the boundary between the processed part and the non-processed part. FIG.
Fig. 1 shows an electron micrograph of a processed spot marked on a color filter substrate for a liquid crystal display by a conventional marking method. Therefore, when a color filter substrate that has been marked by a conventional marking method is used, the fibrous substance peels off to form particles, which causes a problem that the product yield of a liquid crystal display or a plasma display is deteriorated. Therefore, an object of the present invention is to prevent particles from being generated in a subsequent process by marking so that a fibrous substance is not generated.

[0006]

In order to solve the above-mentioned problems, the present invention irradiates a color filter substrate with a constant laser irradiation condition while scanning a laser beam emitted from a laser light source, thereby forming a character, figure or symbol. In the marking method for forming a laser beam, the laser irradiation condition is a method for marking a color filter substrate under a condition that a fibrous substance is not generated at an edge of a processing spot processed when the laser light is irradiated. The laser irradiation conditions include the magnitude of the irradiation output of laser light, irradiation time or irradiation energy, irradiation energy density, and the like. By adjusting the laser irradiation conditions, there are conditions under which no fibrous substance is generated, and if marking is performed under these laser irradiation conditions, particles can be prevented from being generated during and after the marking. As specific laser irradiation conditions, an energy density of 100 J / cm
There is a marking method in which marking is performed by setting the color filter film in a range in which ^two or less color filter films can be processed, and making the spot area of the laser beam equal to the area of the processed spot. Further, as another laser irradiation condition, there is a marking method for performing marking by making the irradiation area of the laser light larger than the area of the processing spot. Specifically, the energy density is set to a range in which a color filter film having a density of 200 J / cm ² or less can be processed. In this way, by irradiating the laser beam to a portion wider than the required processing spot, the temperature gradient near the edge of the processing spot is reduced, and without generating a fibrous substance at the edge of the processing spot. Marking can be performed. Further, the present invention is a color filter substrate on which a character, a number, a barcode or a two-dimensional code is marked by the above-mentioned marking method. In the color filter substrate of the present invention, since no fibrous substance is attached to the edge of the processing spot, particles are not generated in the manufacturing process after marking.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS It has been found by observing with an electron microscope that fibrous substances are generated at the boundary between a processed portion and a non-processed portion when marking is performed on a color filter substrate by a conventional marking method. The result is an electron micrograph of FIG. It has been found that this fibrous substance is the cause of the generation of particles from the marking formation part in the process after marking. Next, it was found out that laser irradiation conditions that do not generate the fibrous substance exist. By the marking method for marking the color filter substrate under the laser irradiation condition in which the fibrous substance is not generated, it is possible to prevent particles from being generated during and after the marking. The laser irradiation conditions include the magnitude of the irradiation output of laser light, irradiation time or irradiation energy, irradiation energy density, and the like.
Laser irradiation conditions can also be adjusted by changing the size of the laser irradiation spot or the scanning speed of the scanning means.

FIG. 1 shows a marking method in which the size of an irradiation spot is changed and a portion wider than a required processing spot is irradiated with a laser beam. In FIG. 1, 1 is a laser light source, 2 and 3 are scanner mirrors used as scanning means, 4 is a condenser lens, and 5 is a color filter substrate. The difference from the conventional marking method of FIG. 10 is that the irradiation spot 6 of the laser beam 8 is configured to be larger than the required processing line width or processing spot 7. Specifically, the color filter film 52 is shifted from the position of the beam waist 9 of the laser light as shown in FIG.
The irradiation spot 6 may be enlarged by arranging. Alternatively, as shown in FIG. 3, a color filter film 52 is arranged so that the beam waist 9 coincides with the irradiation spot 6, and a light source used to make the beam waist 9 larger than the required processing line width or the processing spot 7. The size or the lateral magnification of the lens system may be designed. Normally, the intensity of the laser beam is high at the center of the beam and low at the periphery. Therefore, when laser irradiation is performed in the state shown in FIG. 2 or 3, the temperature of the irradiation spot becomes the highest at the center as shown in FIG. Even if the center of the irradiation spot is heated to a temperature sufficient to cause a physical change, the temperature gradient near the edge of the processing spot remains small. Therefore, the boundary between the processed portion and the processed portion at the edge of the processed spot is formed gently, and marking can be performed without generating a fibrous substance.

[0009]

Embodiments of the present invention will be described below. FIG. 5 shows a marking method according to the first embodiment of the present invention. In FIG. 5, 1 is a laser light source, 10 is a fiber, 2 and 3 are scanner mirrors, 4 is a condenser lens, 5 is a color filter substrate, 11 is a collimator lens, and 12 is a stop. As the laser light source 1, a gas laser such as a semiconductor laser, a carbon dioxide laser, a He—Cd laser, an Ar laser, or an excimer laser, a YAG laser, YVO ₄ , Y
A harmonic laser light source that emits a laser beam having a wavelength of a harmonic component can be used in combination with a solid-state laser such as an LF laser, a glass laser, or a fiber laser, a liquid laser such as a dye laser, or a nonlinear optical crystal. Generally, a carbon dioxide laser and Nd: YAG or Nd: YVO ₄ are used as the processing laser. The oscillation wavelength of 10 μm of the carbon dioxide gas laser deviates greatly from the absorption wavelength of the color filter substrate 5, so that high-power laser light must be irradiated, and the glass is damaged. Nd: YAG or N used for marking
The oscillation wavelength of a solid-state laser such as d: YVO ₄ is 1.06 μm.
m, which is also longer than the absorption wavelength of the color filter substrate 5, so that it is necessary to irradiate laser light with a pulse using a Q switch or the like. Therefore, particles are generated at the time of marking.

Therefore, in the embodiment of the present invention, a semiconductor laser is used as the laser light source 1. Since the absorption wavelength of the color filter substrate 5 is in the visible region or the near infrared region,
By using a semiconductor laser that outputs laser light in this wavelength range, marking can be efficiently performed with low-output laser light, and marking can be performed without generating particles. In addition, the use of a semiconductor laser makes the configuration very simple and the marking device can be downsized. Furthermore, semiconductor lasers are much more efficient than other laser light sources,
There is an advantage that the power consumption of the marking device can be reduced. The rotation of each of the scanner mirrors 2 and 3 used as scanning means can be controlled by a scanner motor (not shown). As the scanning means, an XY stage can be used so that the relative position between the laser light emitted from the marking device and the color filter substrate 5 changes. Between the laser light source 1 and the scanner mirror 2,
Arbitrary optical components such as a collimator lens and a beam expander can be arranged. As the condenser lens 4, an fθ lens was used. The color filter substrate 5 has a color filter film 52 formed on a glass substrate 51.

In the marking device having the above structure, in order to form a 20 × 20 matrix two-dimensional code with a segment diameter of 100 μm, the irradiation spot of the laser beam has the same size as the required processing spot of 100 μm. The aperture 12 is made of the fiber 10 and the collimator lens 1
1 to perform marking. First, when marking was performed under the initial conditions of a laser output of 1.6 W and an irradiation time of 100 ms, that is, an energy density of 500 J / cm ² , a fibrous substance was generated at the edge of the processing spot. By shortening the laser irradiation time while keeping the laser output unchanged, the irradiation time is 10 ms or less, that is, the energy density
Laser irradiation conditions were found in which no fibrous material was generated at the edge of the processing spot of 0 J / cm ² or less. By performing marking under these laser irradiation conditions, it was possible to prevent particles from being generated during and after the marking. A test was conducted on 20 color filter substrates marked by this marking method using a transfer device simulating a liquid crystal display production line, but no particles were generated.

FIG. 6 shows a marking method according to a second embodiment of the present invention. The marking device of the present invention shown in FIG. 6 irradiates a laser beam to a portion wider than a required processing spot. In order to form a 20 × 20 matrix two-dimensional code with a segment diameter of 100 μm, a processing spot of 100 μm where a laser light irradiation spot is required
The position of the color filter substrate 5 was displaced from the beam waist so as to be 200 μm, which is twice as large as that of FIG. When conditions are set in this state, the laser output is 1.6 W, the irradiation time is 20 ms or less, that is, the energy density is 200 J / c.
A condition was found in which no fibrous material was generated at the edge of the processing spot at m ² or less. The reason why fibrous substances are no longer generated even when the energy density is higher than in the first embodiment will be discussed below. As shown in FIG. 4, the temperature is highest at the center of the irradiation spot, and gradually decreases toward the periphery. Even if the center of the irradiation spot is heated to a temperature sufficient to cause a physical change, the heating temperature changes gradually with a gradient. Therefore, the boundary between the processed portion and the processed portion at the edge of the processed spot is formed gently without abrupt state change, and marking can be performed without generating a fibrous substance. As described above, since the allowable energy density at which no fibrous substance is generated becomes large, as shown in FIG. 7, the condition area where the fibrous substance is not generated and the marking can be performed is widened, so that the laser irradiation condition that can process reliably can be selected. Become like Therefore, irradiating the laser beam over a wider area than the required processing spot as in the second embodiment is a preferable method for performing reliable marking.

As a result of a test in which the position of the color filter substrate 5 is changed, the same effect is confirmed when laser light is irradiated to 1.2 to 2.5 times the required processing spot. . When it was smaller than 1.2 times, a fibrous substance was generated from the same energy density as in the first embodiment. If it is larger than 2.5 times, the magnitude of the energy density for generating the fibrous substance becomes constant, and there is no merit of further expanding the irradiation range. FIG. 8 shows an electron micrograph of the processed spot 7 formed under the laser irradiation condition in which the substance in the fiber place is not generated in the second embodiment. No fibrous material is generated at the edge 71 of the processing spot 7. Under this laser irradiation condition, the segment diameter is 100μ.
The result of forming a 20 × 20 matrix with m is shown in FIG. A marking test was performed 500 times or more with the marking device of FIG. 1, and the marking was successfully performed. A transport test was performed on 500 color filter substrates that had been marked by the marking apparatus of the present invention, but no particles were generated.

[0014]

As described above, when the color filter substrate of a liquid crystal display or a plasma display is marked by the marking method of the present invention, no fibrous substance is generated at the edge of the processing spot. Therefore, no particles are generated at the time of marking and at the time of a post-process.
Furthermore, by using the marking method of the present invention, by irradiating a laser beam to a portion wider than the required processing spot, a fibrous shape is formed on the edge of the processing spot in a state where the temperature gradient near the edge of the processing spot is small. Marking can be performed without generating any substance. Therefore, it is possible to sufficiently irradiate the laser so that a processing spot can be formed, and marking can be performed reliably. When a color filter substrate that has been marked by the marking apparatus or the marking method of the present invention is used, particles due to the marking are not generated, so that the product yield of a liquid crystal display or a plasma display using the color filter substrate is improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a marking method according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a first laser irradiation method according to the embodiment of the present invention.

FIG. 3 is a sectional view showing a second laser irradiation method according to the embodiment of the present invention.

FIG. 4 is a sectional view of a color filter during laser irradiation according to the embodiment of the present invention.

FIG. 5 is a schematic view showing a marking method according to the first embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating a marking method according to a second embodiment of the present invention.

FIG. 7 is a schematic diagram showing a process of forming a processing spot in the embodiment of the present invention when laser irradiation is performed using the marking device of the present invention so as not to generate a fibrous substance.

FIG. 8 is an electron micrograph of a processing spot formed by the marking device of the present invention.

FIG. 9 shows a marking device according to an embodiment of the present invention.
This is a two-dimensional code marked on the liquid crystal color filter substrate.

FIG. 10 is a schematic diagram showing a conventional marking device.

FIG. 11 is an electron micrograph of a processing spot formed by a conventional marking device.

[Explanation of symbols]

Reference Signs List 1 laser light source, 2 scanner mirror, 3 scanner mirror, 4 condenser lens, 5 color filter substrate, 51
Glass substrate, 52 color filter film, 6 irradiation spot, 7 processing spot, 71 edge of processing spot,
8 laser beam, 9 beam waist, 10 fiber, 1
1 collimator lens, 12 aperture

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hirotoshi Hayakawa 2-1 Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu City, Fukuoka Prefecture (72) Inventor Jin Wakisako 2-1 Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu City, Fukuoka Prefecture No. F-term in Yaskawa Electric Corporation (reference) 4E068 AB00 CA02 CA11 DA11

Claims (5)

[Claims] 1. A marking method for irradiating a color filter substrate with a constant laser irradiation condition while scanning a laser beam emitted from a laser light source to form a character, a figure, or a symbol. A method for marking on a color filter substrate, characterized in that the condition is such that no fibrous substance is generated at the edge of a processing spot processed when light is irradiated. 2. The laser irradiation condition is such that an energy density is in a range in which a color filter film having a density of 100 J / cm ² or less can be processed, and a spot area of the laser beam is made equal to an area of the processed spot. The method for marking on a color filter substrate according to claim 1, wherein: 3. The method for marking on a color filter substrate according to claim 1, wherein the laser irradiation condition is such that an irradiation area of the laser beam is larger than an area of the processing spot. 4. The method for marking on a color filter substrate according to claim 3, wherein the laser irradiation conditions are such that the energy density is within a range in which a color filter film having a density of 200 J / cm ² or less can be processed. 5. A color filter substrate on which a character, a numeral, a barcode or a two-dimensional code is marked by the marking method according to claim 1.