JP2000176670A - Optical processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical processing device capable of making miniaturization compatible with the improvement of a processing speed by preventing the generation of variance of a processing dimension and a finished state or the like and reducing the diameter of a light beam while controlling the reduction of light beam power without using an optical system such as a mirror having many restrictions on a layout. SOLUTION: This device is provided with a YAG laser 1, a step index side optical fiber 2 which guides a light beam emitted from the laser 1 up to the vicinity of a substrate 3 being a workpiece while uniformizing energy density by refraction and reflection in an internal optical transmission line, a lens 20 for irradiating the substrate 3 by squeezing the light beam emitted from the light emitting end of the optical fiber 2 into a spot shape, and a mounting pedestal 5b on which the substrate 3 is placed and moreover which is driven and controlled in the direction crossing with the irradiating direction of the light beam. At least the end part 2c of the light emitting end side of the optical fiber 2 is formed so that the cross section area of a core 2a becomes narrow as the end part advances toward the downstream side in the advancing direction of the light beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of irradiating a conductive film formed on an insulating substrate with a light beam in order to form an electrode pattern on the surface of the insulating substrate such as a touch panel or a liquid crystal panel. The present invention relates to an optical processing apparatus that performs processing for removing a part of the conductive film, and processing for forming a through hole or a concave portion by irradiating a plastic material or the like with a light beam.

[0002]

2. Description of the Related Art Conventionally, a touch panel has been used as a means for a user to input information to various electronic devices. In addition, a liquid crystal panel is used as a display unit of the electronic device. Such a touch panel and a liquid crystal panel have a structure in which a pair of insulating substrates each having a transparent electrode made of a transparent conductive film formed on a surface thereof are bonded so that the transparent electrodes face each other. In the case of a touch panel,
The set of substrates is opposed to each other via a spacer having a predetermined height (for example, 9 to 12 μm) so that the transparent electrodes do not contact in a normal state.

The transparent electrodes formed on the surface of the insulating substrate are separated by slit-shaped gaps so as not to contact each other. Conventionally, the wiring pattern of the transparent electrode on the insulating substrate has been mainly formed by a photolithography method including an etching process. In this photolithography method, a conductive film is formed on the entire surface of an insulating substrate by vacuum evaporation or the like, a resist pattern is formed on the conductive film, and then the exposed portion of the conductive film is dissolved with an etchant. After removal, an insulating pattern is formed to form a wiring pattern of a conductive film.

[0004]

However, when the above-described photolithography method is used, a waste liquid such as a developing solution or an etching solution for the photoresist is generated, which is not preferable from the viewpoint of environmental protection. Also, when changing the pattern shape of the transparent electrode, a new mask for photolithography must be created, resulting in poor processing efficiency.
It was difficult to cope with low-volume production of other products and to reduce costs.
In particular, even when a few slits are formed in a conductive film on an insulating substrate such as a hybrid touch panel, the same photolithography process as in a digital touch panel that forms several hundred slits is performed. Since it becomes necessary, it is difficult to reduce the waste liquid and reduce the cost even though the number of processed parts is small.

[0005] Therefore, there is no need for waste liquid treatment as in the case of using the photolithography method including the above-mentioned etching treatment. Processing using a beam is conceivable. The inventor of the present invention has conducted intensive experiments and the like on the processing of the conductive film by the laser irradiation. As a result of the energy distribution in the cross section of the laser beam, the width of the slit after processing was irregular and wavy. It has been found that problems such as a shape, a part of the conductive film remaining, and an insulative substrate being dug deep at a position corresponding to the center of the laser beam may occur.

In an apparatus configured to guide the light beam of the light source to a processing portion of an object to be processed by an optical system using a mirror or a lens, there is not much freedom in arrangement of the mirror and the like, and the light source, the optical system and There are many restrictions on the layout of the mounting table, and it has been difficult to reduce the size of the apparatus. In order to reduce the size of the apparatus, it is conceivable to use a small-diameter lens or the like by reducing the diameter of the light beam. However, if it is attempted to reduce the diameter of the light beam by the light shielding shape of the aperture, the light beam Power may decrease, and a predetermined processing speed may not be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and an object of the present invention is to prevent the occurrence of variations in processing dimensions and finished states due to non-uniform energy distribution in a cross section of a light beam, and to improve layout. Light that can achieve both miniaturization of the apparatus and improvement of the processing speed by reducing the diameter of the light beam without using an optical system including mirrors and lenses with many restrictions and while suppressing the decrease in the light beam power It is to provide a processing device.

[0008]

To achieve the above object, according to the present invention, a light source for emitting a light beam and a light beam emitted from the light source are refracted by an internal optical transmission line. An optical fiber that guides the vicinity of the processing object while making the energy density uniform by reflection, and an irradiation optical member for irradiating the processing object by narrowing the light beam emitted from the light emitting end of the optical fiber into a spot shape. A mounting table on which the processing object is mounted and which can be driven and controlled in a direction intersecting with the irradiation direction of the light beam, wherein at least an end portion of the optical fiber on a light emitting end side. To
The cross section of the optical transmission path is formed to be narrower toward the downstream side in the traveling direction of the light beam.

In the processing apparatus of the first aspect, when the light beam emitted from the light source is guided by the optical fiber, the light beams incident at different angles are multiplexed on the optical transmission line inside the optical fiber. By being refracted or reflected, the energy density in the cross section of the light beam emitted from the optical fiber becomes uniform. In addition, since the cross-sectional area of the optical transmission line becomes narrower at least at the light emitting end of the optical fiber toward the downstream side in the traveling direction of the light beam, the light beam is cut off at the optical transmission line. When passing through a portion having a reduced area, the diameter of the light beam is reduced with less power reduction than when an aperture is used. The light beam having a uniform energy density and a reduced diameter is radiated to a processing object by being narrowed down into a spot by an irradiation optical member, and the processing object is processed.

A second aspect of the present invention is the optical processing apparatus according to the first aspect, wherein a step index type optical fiber having a core at a shaft core is used as the optical fiber.

In the processing apparatus according to the first aspect, when the light beam emitted from the light source is guided by the optical fiber, the light beams of the light beam incident at different angles are reflected multiplely by the core inside the optical fiber. Thereby, the energy density in the cross section of the light beam emitted from the optical fiber becomes uniform. Moreover, since the cross-sectional area of the core decreases at least at the light emitting end of the optical fiber toward the downstream side in the traveling direction of the light beam, the cross-sectional area of the core decreases. When passing through the portion where the light beam passes, the diameter of the light beam becomes smaller with less power reduction than when an aperture is used. The light beam having a uniform energy density and a reduced diameter is radiated to a processing object by being narrowed down into a spot by an irradiation optical member, and the processing object is processed.

According to a third aspect of the present invention, in the optical processing apparatus of the first or second aspect, instead of providing the irradiation optical member,
The light emitting end of the optical transmission line of the optical fiber is formed in a convex lens shape.

In the processing apparatus according to the third aspect, the light beam emitted from the optical transmission line of the optical fiber is processed by being narrowed down to a spot shape at a portion of the light emitting end of the optical transmission line which is formed in a convex lens shape. The object is irradiated.

Incidentally, a graded index type optical fiber can be used as the optical fiber. Further, a light-blocking member may be provided for passing only the central portion of the light beam emitted from the light emitting end of the optical fiber, where the energy density is uniform. In this case, the energy density of the light beam applied to the workpiece is made more uniform,
The energy distribution can be sharply changed at the outer peripheral end in the cross section of the light beam, and the occurrence of variations in processing dimensions and finished state can be more reliably prevented.

Further, the above-mentioned invention can be applied to a case where a slit is formed in a transparent conductive film on a transparent insulating substrate. In the case of this processing, a light beam whose energy distribution emitted from the step index type optical fiber is uniform and whose diameter is reduced is narrowed down into a spot shape by an irradiation optical member, and is formed on the transparent insulating substrate. By irradiating the transparent conductive film,
The conductive film is processed into a slit shape. A light beam having a uniform energy distribution can be applied to a transparent conductive film on a transparent insulating substrate. Accordingly, variation in the width of the slit formed in the conductive film, a part of the conductive film remaining in the slit, damage to the insulating substrate in the slit, and the like can be reduced, and the edge of the slit can be reduced. The unevenness can be reduced, and the visibility of the slit can be reduced.

Further, the above-mentioned invention can be applied to a case where processing is performed so as to form a slit for insulation between wirings around a wiring pattern made of conductive paste on the surface of a conductive film on an insulating substrate. . In the case of this processing, a light beam whose energy distribution emitted from the step index type optical fiber has been made uniform and whose diameter has been reduced is narrowed into a spot shape by an irradiation optical member, and the conductive material on the insulating substrate is electrically conductive. Irradiation is performed on a film having a wiring pattern made of a conductive paste formed on the surface, and the film is processed so as to form a slit for wiring insulation around the wiring pattern on the conductive film. The light beam having the uniform energy distribution can be applied to a conductive film on an insulating substrate having a wiring pattern formed of a conductive paste on the surface. Therefore, it is possible to reduce the variation in the width of the slit for wiring insulation formed in the conductive film, the remaining of a part of the conductive film in the slit, the damage of the insulating substrate in the slit, and the like.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which the present invention is applied to a processing apparatus for forming a transparent electrode by removing a part of a conductive film in a slit shape on a transparent insulating substrate in a hybrid type touch panel. explain.

FIG. 1A is a schematic configuration diagram of a processing apparatus according to the present embodiment. This processing apparatus guides a YAG laser 1 as a light source controlled by a Q switch 1a and a near-infrared laser beam (wavelength λ = 1064 nm) as a light beam emitted from the YAG laser 1 to the vicinity of a processing target. And a step index type optical fiber 2. An insulating substrate 3 made of a transparent plastic material (for example, PET or polycarbonate) having a conductive film 4 as a processing object made of a transparent material (for example, ITO) formed on a surface thereof is a linear motor of an XY stage 5. (For example, a servomotor or a stepping motor), which is fixed on a mounting table 5b driven by a 5a, and is movable two-dimensionally in the horizontal direction in the figure. The YAG laser 1 and the XY stage 5 are controlled by a control unit 6 as control means including a computer 6a, a sequencer 6b, and a control circuit board 6c for synchronously linked operation. For example, the control unit 6
The AG laser 1 is controlled, whereby the repetition period, pulse width, and the like of the laser beam are changed. The XY stage 5 is provided with a linear sensor (for example, a linear encoder or a linear scale) for detecting the moving distance of the mounting table 5b, and the mounting table 5b is feedback-controlled based on the output of the linear sensor. You may comprise.

FIG. 1B is an enlarged sectional view of an end of the optical fiber 2 on the light emitting end side. The optical fiber 2 is composed of a core at the center of the axis and a clad at the outer periphery having a smaller refractive index than the core. The end of the optical fiber 2 on the light incident end side is connected to the light emitting portion 1b of the YAG laser 1, and laser light from the laser is incident on the core of the optical fiber 2 by an optical member such as a lens (not shown). . As shown in FIG. 1B, a tapered portion 2c is formed at the light emitting end of the optical fiber 2 so that the cross-sectional area of the core 2a becomes smaller toward the downstream side in the traveling direction of the laser light. ing. As described above, since the cross-sectional area of the core 2a becomes narrower toward the emission end side, the laser beam that is multiply reflected and guided in the core 2a has a beam diameter without decreasing the light beam power. It gets smaller.

The distal end of the optical fiber 2 is held by a holding member 21 attached to the apparatus body.
A lens 20 as an irradiation optical member is mounted inside the holding member 21. Core 2 of optical fiber 2
The small-diameter laser light emitted from a is condensed by the lens 20 and is irradiated on the conductive film 4 in a spot shape through the beam passage opening 21 a of the holding member 21. The conductive film 4 is heated and evaporated by selectively irradiating the conductive film 4 with the laser light condensed by the lens 20, and thereby the conductive film 4 is heated.
Can be partially peeled off. Since the processing for removing a part of the transparent conductive film 4 on the insulating substrate 3 by irradiating the laser beam is performed as described above, the waste liquid processing such as the case of using the photolithography method including the etching processing is performed. Without this, it is possible to produce a touch panel having a transparent electrode at a low cost in a small amount of other types.

FIG. 1C is an enlarged cross-sectional view of the tip end of the optical fiber 2 and the holding member 21. Holding member 2
1 has a gas inlet 21b for introducing an assist gas near the lens 20. A part of the assist gas introduced from the inlet 21b flows along the surface of the lens 20 as shown by an arrow in the figure, and the beam passing port 21a
Is discharged from This assist gas prevents dust from adhering to the lens surface and prevents a part of the conductive film 4 peeled off from the insulating substrate 3 by laser light irradiation from entering the inside of the holding member 21.

FIG. 2 is a sectional view of a touch panel processed by the present processing apparatus. FIGS. 3A and 3B are an exploded perspective view and a plan view of the touch panel, respectively.
As shown in FIG. 2, the touch panel has a pair of upper and lower touch panel substrates 7 and 8 at a predetermined height (eg, 9
.mu.m). When the touch panel is pressed from above in FIG. 2, the upper touch panel substrate 7 is deformed as shown by a two-dot chain line, and the transparent electrodes of the upper and lower panels 7 and 8 are in contact with each other.
From the change in resistance between the upper and lower transparent electrodes due to this contact, it is possible to know whether or not the pressing has been performed and the pressed position. This touch panel is a hybrid type combining an analog type and a digital type. As shown in FIG. 3, slits 7a, 8a orthogonal to each other are formed on each of the upper and lower touch panel substrates 7, 8, respectively. ing.

The processing apparatus according to this embodiment forms the slits of the conductive film 4 shown in FIG. The insulating substrate 3 having the conductive film 4 (thickness: about 500 Å) formed on the surface thereof by vacuum deposition, ion plating, sputtering, or the like, is placed on the XY stage 5 toward the upper side of the conductive film 4. Is set to And
The laser beam L is moved to one direction by the XY stage 5 while irradiating the conductive film 4 on the insulating substrate 3 with the laser beam L being focused to a predetermined spot diameter, so that the width is 500 to 1000 μm.
To this extent, the conductive film 4 is removed by being evaporated by heating with a laser beam, and a slit for insulating each electrode region is formed.

Here, the energy distribution in the cross section of the laser beam L emitted from the YAG laser 1 is shown in FIG.
As shown in (a), the center has the strongest mountain-shaped profile. The level indicated by the symbol Eo in FIG.
It shows the threshold value for the removal processing of the conductive film 4 by laser light. When the conductive film 4 on the insulating substrate 3 was removed by directly irradiating a laser beam having the energy distribution of such a profile, the slit 10 was formed as shown in FIGS. 4B and 4C. Is not constant,
It became wavy. Therefore, leakage due to moisture or leakage due to adhesion of the conductive foreign matter 102 is likely to occur,
The wavy edge of the slit 10 is notable in that the transparent electrode is easily visible. In addition, slit 10
It is difficult to control the width of the conductive film, and the processing residue 101 in which a part of the conductive film remains is easily generated. The visibility is also increased by the unprocessed portion 101. Further, as shown in FIG. 4B, the insulating substrate 3 is dug deep at a position corresponding to the center of the laser beam L, or the processed portion is scorched and colored, thereby increasing the visibility of the slit. There was also a problem of rolling.

In order to solve various problems caused by the energy distribution of the laser light, in the present embodiment, an optical system for guiding the laser light from the light source 1 to the conductive film 4 is provided.
The above-described step index type optical fiber 2 which can make the energy distribution in the cross section of the laser beam L uniform is used.

As shown in FIG. 5A, the insulating substrate 3 is used by using the step index type optical fiber 2.
By making the energy distribution in the cross section of the laser beam L applied to the upper conductive film 4 uniform at a level slightly exceeding the threshold value Eo, the slit is formed as shown in FIGS. 5B and 5C. The width of 10 can be fixed to a predetermined width. Therefore, leakage due to moisture or conductive foreign matter 10
Leakage due to adhesion of 2 is less likely to occur, and the edge of the slit 10 is less noticeable. In addition, the width of the slit 10 can be easily controlled, and processing residue with a part of the conductive film 4 remaining hardly occurs. Further, as shown in FIG. 5B, the insulating substrate 3 is not dug deep at a position corresponding to the center of the laser beam L. Further, since the processed portion is not scorched and colored, the visibility of the slit does not increase.

As described above, according to the present embodiment, the laser beam applied to the conductive film 4 is guided by the step index type optical fiber 2, thereby making the energy distribution in the cross section of the laser beam uniform. Variations in processing dimensions, partial residue of the conductive film, damage to the insulating substrate, and the like can be reduced. Moreover, since the diameter can be reduced while suppressing the light beam power reduction without using an optical system including mirrors and lenses, which have many layout restrictions, it is possible to achieve both miniaturization of the apparatus and improvement of the processing speed. Can be.

A holding member 21 holding the lens 20
In the device for introducing the assist gas into the inside of the lens, the lens 20
Although a large temperature distribution occurs in the inside of the lens and thermal deformation easily occurs with time, the diameter of the lens 20 can be reduced in accordance with the reduction in the diameter of the laser beam in the apparatus of the present embodiment. The distribution can be reduced. Accordingly, thermal deformation of the lens 20 with time is unlikely to occur, and a stable irradiation optical system can be configured.

Further, by using the step index type optical fiber 2, the shape of the spot of the laser beam irradiated on the conductive film 4 becomes circular. , The wave of the edge of the slit 10 when moved in an oblique direction deviated from the Y direction is compared with a case where the energy distribution is made uniform using a normal kaleidoscope in which the spot shape of the laser beam is square. Then, it can be made smaller.

Also, when trying to reduce the beam diameter of the laser light using a kaleidoscope, the inclination angle of the light reflecting surface cannot be increased in order to prevent the laser light from going back to the light source side. Callide scope becomes elongated in a straight line. On the other hand, when the optical fiber 2 that can be freely bent within a predetermined curvature range as in the present embodiment is used, the total length of the optical fiber is reduced in order to reduce the diameter of the laser light and make the energy distribution uniform. Even if the length is long, the degree of freedom of the layout of the optical system and the XY stage is not limited, so that the device can be downsized and the device design becomes easy.

The laser light is a laser light of infrared light or visible light emitted from the YAG laser 1 as a heat laser, and a part of the conductive film 4 is mainly heated and evaporated. Therefore, the insulating substrate 3 (PET, polycarbonate, etc.) that is the base of the conductive film 4 is less colored and damaged.

Further, by using the Q-switch controlled YAG laser 1, the setting of the thermal energy applied to the conductive film 4 can be changed by changing the repetition period and irradiation time width (pulse width) of the laser light. The removal processing of the conductive film 4 is easily controlled.

In this embodiment, as shown in FIG. 1 (b), the cross-sectional area of the cladding 2b together with the core 2a and the core 2a is increased as the light emitting end of the optical fiber 2 moves downstream in the traveling direction of the laser light. 6A, the cross-sectional area of the clad 2 may be kept as it is, and only the cross-sectional area of the core 2a may be gradually narrowed as shown in FIG. Further, the cross-sectional area of the core 2a may be gradually reduced over the entire length of the optical fiber in addition to the end. Further, as shown in FIG. 6B, the light emitting end of the core 2a of the optical fiber 2 may be formed in a convex lens shape. In this case, even if the lens 20 is not provided, the laser light emitted from the core 2a can be focused and irradiated on the conductive film 4 in a spot shape.
The reflection surface of the laser beam is reduced, so that the reduction of the light beam power can be further prevented, and the size of the apparatus can be further reduced.

Further, in this embodiment, the step index type optical fiber 2 is used in which the diameter of the core gradually decreases as it goes to the light emitting end side, but the diameter of the shaft core portion where the refractive index is high is used. May be used as a graded index type optical fiber whose size gradually decreases toward the light emitting end. Further, a light-shielding member may be provided for passing only the central portion of the light beam emitted from the light emitting end of the optical fiber, where the energy density is uniform.

In this embodiment, YAG is used as a light source.
Although a laser is used, another laser such as a carbon dioxide laser or the like that can emit infrared light or visible laser light, or another light source such as a lamp may be used.

Further, in the above-described embodiment, the processing of forming a slit 10 for partitioning each transparent electrode by removing a part of the conductive film 4 to form a transparent electrode of the touch panel has been described. As shown in FIG. 7, the processing device (1) forms a slit 14 for insulating wiring between wirings around a wiring pattern 13 made of a conductive paste (for example, silver paste) formed on the surface of the conductive film 4 on the insulating substrate. It can be used also in the case of forming, and a similar effect can be obtained.

In each of the above embodiments, the case where the present invention is applied to the processing of a conductive film for forming a transparent electrode of a touch panel has been described. However, the present invention is not limited to the touch panel, but may be, for example, a transparent electrode of a liquid crystal panel. The present invention can be applied to a case where a conductive film for forming is processed, and a similar effect can be obtained. The present invention can also be applied to a case where a process of forming a through hole or a concave portion by irradiating a light beam to a plastic material for a print mask or the like is performed.

[0038]

According to the first to third aspects of the present invention, the object to be processed is irradiated with the light beam having a uniform energy distribution in the cross section after passing through the step index type optical fiber. In this case, it is possible to prevent variations in processing dimensions due to non-uniform energy distribution in the cross section. Moreover, since the diameter can be reduced while suppressing the light beam power reduction without using an optical system including mirrors and lenses, which have many layout restrictions, it is possible to achieve both miniaturization of the apparatus and improvement of the processing speed. There is an effect that can be.

In particular, according to the third aspect of the present invention, the light beam emitted from the core of the optical fiber is focused to a spot and irradiated to the workpiece without providing an irradiation optical member such as an individual lens. Can be. Therefore, as compared with the case where an irradiation optical member such as an individual lens is provided, there is an effect that the reflection surface of the laser beam is reduced, the decrease in the light beam power is reduced, and the apparatus can be further downsized. .

[Brief description of the drawings]

FIG. 1A is a schematic configuration diagram of a processing apparatus according to an embodiment of the present invention. (B) is an enlarged sectional view of the end part of the optical fiber used in the processing apparatus on the light emitting end side. FIG. 3C is an enlarged cross-sectional view of the tip of the optical fiber and a holding member.

FIG. 2 is an enlarged sectional view of a touch panel.

FIG. 3A is an exploded perspective view of a touch panel. (B) is a plan view of the touch panel.

FIG. 4A is an explanatory diagram showing an energy distribution in a cross section of a laser beam immediately after emission from a YAG laser.
(B) is a perspective view of a conductive film on an insulating substrate when processed by the same laser beam. (C) is a plan view of a conductive film on the insulating substrate.

FIG. 5A is an explanatory diagram showing an energy distribution in a cross section of a laser beam after passing through an optical fiber. (B) is a perspective view of a conductive film on an insulating substrate processed by the laser light.
(C) is a plan view of a conductive film on the insulating substrate.

FIG. 6A is an enlarged cross-sectional view of an end portion on the light emitting end side of an optical fiber according to a modification. (B) is an expanded sectional view of the tip part of the optical fiber concerning other modifications.

FIG. 7 is an explanatory diagram of a wiring pattern at a peripheral end of a touch panel and slits around the wiring pattern.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 YAG laser 1a Q switch 1b Light emitting part 2 Optical fiber 2a Core 2b Cladding 2c Taper part 3 Insulating substrate (transparent substrate) 4 Conductive film 5 XY stage 5a Linear motor 5b Mounting table 6 Control part 13 Wiring pattern 14 Slit for wiring insulation 20 Lens 21 Holding member 21a Beam passing port 21b Gas inlet

Claims (3)

[Claims] A light source for emitting a light beam, and an optical fiber for guiding the light beam emitted from the light source to the vicinity of a workpiece while making the energy density uniform by refraction or reflection in an internal optical transmission line. An irradiation optical member for squeezing a light beam emitted from a light emitting end of the optical fiber into a spot shape and irradiating the processing object with the processing object; and the processing object is placed and intersects with the irradiation direction of the light beam. An optical processing apparatus comprising: a mounting table that can be driven and controlled in a direction, wherein at least an end of the optical fiber on the light emitting end side is cut off as the light beam travels downstream in the traveling direction of the light beam. An optical processing apparatus characterized in that the area is reduced. 2. An optical processing apparatus according to claim 1, wherein a step index type optical fiber having a core at a shaft core is used as said optical fiber. 3. The optical processing apparatus according to claim 1, wherein the light emitting end of the core of the optical fiber is formed in a convex lens shape instead of providing the irradiation optical member.