JP2010105016A - Laser beam machining method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for halving by laser which can reduce a problem of staining of a focus lens and a workpiece caused by generated transpired gas, in halving a resin film by laser. <P>SOLUTION: When a film with a resin layer formed on an electromagnetic wave shield layer is irradiated with a laser beam converged by a lens, and a part of the film in the thickness direction is removed, the periphery of an optical path of the laser beam passed through the lens is covered with a casing that has an irradiation port of the laser beam, and the irradiation port is separated from the film at least by 10 mm, and while air is supplied into the casing, the transpired gas is exhausted outside the casing, so that a pressure inside the casing is set to +0.02 MPa to +0.05 MPa relative to the pressure of the atmosphere in which the film is disposed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a processing method and apparatus that can be particularly suitably used for half-cut processing in which only a part of a workpiece such as a resin film is melted and evaporated using a laser. More specifically, the present invention relates to a technique for preventing evaporation from adhering to a laser optical system (particularly, the final focus lens surface), and further preventing damage to the optical system due to adhesion of evaporation and adhesion of transpiration to a workpiece.

  In recent years, laser (light amplification by stimulated emission of radiation) light has a high energy density with respect to the irradiation region, and the irradiation region can be designed based on an optical design. Furthermore, YAG (Yttrium Aluminum Garnet), carbon dioxide (CO2) ) Along with the realization of laser oscillation tubes that can oscillate high energy such as lasers and their price reductions, the applications have been expanded to applications that were previously unthinkable, such as ablation processing for half-cutting resin film laminates. It has come to be widely used for processing (Patent Document 1).

  Although it is a laser processing having the above characteristics, it is known that when used for ablation processing, the work piece melts and evaporates to generate a transpiration gas, which causes the following problems. That is, there are problems in the case where the generated transpiration gas has toxicity, flammability, and the like, and various problems caused by the attachment of the transpiration gas.

  Especially in the case where transpiration gas adheres, the transpiration gas is solidified by lowering to a temperature below its melting point in the atmosphere, and it adheres as a suspended or adhering substance, or the work piece or the processing apparatus itself as it is in the gas state. It may come into contact with the surrounding environment and be cooled and solidified directly on the surface. The former is simply adhesion to the surface, and its removal is easy, but in the latter, the transpiration is generated and grown by vapor phase growth, and therefore the adhesion and adhesion are very strong.

  More specifically, in the laser processing apparatus, the laser optical system, particularly the focus lens closest to the workpiece, is exposed to the vaporized gas immediately after generation. For this reason, the transpiration gas is solidified on the lens surface, and a coating layer is formed on the lens surface, and the internal stress of the coating layer causes distortion / cracking of the lens or peeling of the optical coating applied to the lens. Sometimes. Furthermore, the optical transparency is lost due to the coating layer of the transpiration material generated on the lens surface, and the laser beam may be absorbed and diffused by the lens. In particular, when laser light is absorbed, the absorbed energy is transferred to the lens as thermal energy, which may lead to thermal destruction of the lens.

  Further, when the transpiration gas stays in the vicinity of the processing portion, the transpiration gas absorbs or reflects the laser beam, which may cause the laser energy to be attenuated in the optical path. In this case, the laser beam cannot obtain a predetermined energy in processing, and is in a state where the processing capability expected in processing speed, depth, width, etc. cannot be exhibited.

  To solve these problems, attempts have been made to solve the problems described in Patent Documents 2 to 4 from the viewpoint of preventing evaporation from adhering to a laser optical system, particularly a focus lens.

  These are: (i) a gas injection nozzle and a gas suction nozzle arranged oppositely between the lens and the workpiece to prevent the evaporation from adhering to the lens; (ii) the laser processing apparatus. Injecting gas to the laser irradiation port of the laser head, which can be an intrusion port for transpiration gas, to form an air flow from the inside of the laser head to the outside, or (iii) Transmitting laser light to the laser irradiation port of the laser head By providing a transparent glass or a periclic membrane of cellulose polymer, the opening for the transpiration gas is closed to prevent intrusion.

  However, these methods cannot prevent the transpiration gas generated in the workpiece irradiated with the laser from touching the surface of the workpiece, and as a result, the evaporation from the workpiece. That is, in the method (i), there is a risk that an air flow containing a transpiration gas may be blown onto the work piece due to a swirling flow caused by an upper gas and a lower gas being entrained in an air flow from a nozzle arranged oppositely. There is. Further, in the method (ii), since the air flow including the transpiration gas is blown onto the work piece by the air flow generated by the gas injection, the attachment of the transpiration material to the work piece may become more conspicuous. Further, in the method (iii), the attachment to the window member occurs instead of the attachment to the focus lens so far.

  As described above, according to the proposed method, the contamination of the optical system due to the transpiration gas seems to be a temporary solution, but it cannot be a device that can simultaneously solve the contamination generated on the workpiece and other members. The problem with transpiration gas still remains.

  On the other hand, there has been proposed a method of sucking and exhausting a vaporized gas in the vicinity of a work piece where the gas is generated in laser irradiation for silicon wafer cleaving.

  For example, in Patent Document 5, high-pressure gas is blown out from a laser irradiation port of a nozzle to prevent invasion of vaporized gas into the laser head, thereby preventing contamination of the optical system and exhausting to the outer periphery of the laser irradiation port of the nozzle. A method of simultaneously preventing contamination of the optical system inside the laser head and the workpiece by a method of providing a nozzle for gas and simultaneously discharging gas from the laser head and exhausting the vaporized gas is described.

However, in this method, only a very limited region of a high-melting-point work piece (the melting point of the silicon wafer in Patent Document 5 is 1410 ° C.), such as when forming a scratch as a starting point for cleaving a silicon wafer, is used. Although it may be a useful method in processing to be performed, when processing a resin film having a coating layer for a PDP filter to form a linear groove having a width of 500 μm, a depth of 30 μm, and a length of 500 mm, for example The amount of transpiration gas generated increases, and the melting point of the coating layer is about 150 to 200 ° C., so it is difficult to exhaust all of the transpiration gas generated from the workpiece, and the transpiration was not sucked. The gas hits the surface of the workpiece by the high-speed flow of high-pressure gas blown out from the laser irradiation port (increased by the nozzle effect) There is a possibility that the surface of the workpiece is cooled and solidified and firmly adhered to form a coating layer. That is, it may be unavoidable that the transpiration material adheres to the surface of the workpiece.
JP 2004-327720 A JP-A-62-187591 JP-A-5-228680 Japanese Patent Application Laid-Open No. 08-066790 Japanese Patent Laid-Open No. 2005-88068

In the present invention, the amount of transpiration gas generated by laser irradiation is large, and even when the work piece has a low melting point, the transpiration gas is cooled and solidified on the surface of the optical system and the work piece. It is an object of the present invention to provide a method and an apparatus capable of sufficiently preventing an object from adhering to the surfaces.

The above object of the present invention has been basically achieved by any of the following inventions (1) to (4).
(1) When a film having a resin layer provided on an electromagnetic wave shielding layer is focused with a lens and irradiated with a laser beam, a part of the thickness direction of the film is removed. Cover the periphery with a casing provided with a laser light irradiation port, separate the irradiation port from the film by at least 10 mm, and exhaust the vaporized gas outside the casing while supplying air to the inside of the casing. Is a laser processing method in which the pressure is +0.02 MPa to +0.05 MPa with respect to the pressure of the atmosphere in which the film is disposed.
(2) A laser processing apparatus for irradiating a film having a resin layer on an electromagnetic wave shielding layer with laser light and removing a part of the film in the thickness direction, a laser oscillator for generating laser light, and a laser A lens for condensing the light on the film, a casing that fixes the lens and covers the periphery of the optical path of the laser light that has passed through the lens, an air supply means to the inside of the casing, and the outside of the casing A transpiration gas exhaust means, and the casing is disposed such that the laser light irradiation port is at least 10 mm away from the film.
(3) The laser processing apparatus according to (2), further including a plate-like member having an opening serving as a laser light path between the laser light irradiation port and the film.
(4) A film in which a resin layer is provided on an electromagnetic wave shielding layer is irradiated with a laser by the method described in (1) above or the apparatus described in (2) or (3) above to remove the resin layer. A method for manufacturing a filter for PDP.

  According to the present invention, even when the amount of transpiration gas generated by laser irradiation is large and the melting point of the workpiece is low, the transpiration gas is cooled and solidified on the surface of the optical system and the workpiece. Since this can be sufficiently prevented, the transpiration can be prevented from sticking to the surfaces. Therefore, if a film with a resin layer provided on an electromagnetic wave shielding layer is irradiated with a laser by the method or apparatus of the present invention and half-cut, the problem of contamination of the optical system in the laser head due to ablated gas generated by ablation In addition, laser half-cut without the problem of contamination of the workpiece due to adhesion of transpiration gas can be realized, and a PDP filter can be manufactured efficiently.

  The laser processing apparatus of the present invention uses a film in which a resin layer is provided on an electromagnetic wave shielding layer as a workpiece, and irradiates the film with laser light to remove a part in the thickness direction of the film. This is a so-called half-cut processing device. In addition, half-cut processing is processing which cuts and removes a part in the thickness direction on the processed surface side of the workpiece, and in the present invention, the entire thickness is partially cut and removed. Are also included.

  In the film to be processed, an electromagnetic wave shielding layer is provided on a base film serving as a base material, and a resin layer that exhibits various functions is further provided thereon. As the base film to be a base material, for example, a plastic film is preferable, and as a resin constituting the plastic film, a polyester resin such as polyethylene terephthalate and polyethylene naphthalate, a cellulose resin such as triacetyl cellulose, polyethylene, polypropylene, polybutylene, and the like Polyolefin resin, acrylic resin, polycarbonate resin, arton resin, epoxy resin, polyimide resin, polyetherimide resin, polyamide resin, polysulfone resin, polyphenylene sulfide resin, polyether sulfone resin, and the like. Among these, polyester resins, polyolefin resins, and cellulose resins are preferable, and polyester resins are particularly preferably used. As the thickness of the plastic film, a range of 50 to 300 μm is appropriate, but a range of 90 to 250 μm is particularly preferable from the viewpoint of cost and ensuring the rigidity of the display laminate. Moreover, it is preferable to provide an undercoat layer (primer layer) for enhancing adhesion (adhesive strength) with an electromagnetic wave shielding layer or a near infrared shielding layer described later.

  Next, examples of the electromagnetic wave shielding layer include a transparent conductive mesh. The electromagnetic shielding layer made of a conductive mesh preferably has a lower surface resistance, preferably has a surface resistance of 3Ω / □ or less, more preferably 1Ω / □ or less, and particularly preferably 0.5Ω / □ or less. The lower limit surface resistance value is about 0.01Ω / □.

  The conductive mesh is (A) a method of etching a metal thin film, (B) a method of plating on a printing pattern, (C) a method of using a photosensitive silver salt, and (D) a metal film laminated on the printing pattern. It can be formed by a method of developing later, etc. Among them, (A) It is preferable to form by a method of etching a metal thin film. In particular, the formation of a metal thin film, a known gas such as sputtering, ion plating, vacuum deposition, or plating with a metal (eg, silver, gold, palladium, copper, indium, tin, or an alloy of silver and other metals). After performing using the layer growth method, it is preferable to perform pattern formation by the etching process by the photolithographic method.

  Examples of the mesh pattern of the conductive mesh include a lattice mesh pattern made up of squares, rectangles, rhombuses, etc., a mesh pattern made up of triangles, pentagons or more polygons, a mesh pattern made up of circles, ellipses, and the above composite shapes And a random mesh pattern. Among these, a grid mesh pattern is preferable from the viewpoint of productivity and ease of product management, and a grid mesh pattern made of a square is particularly preferable.

  The conductive mesh preferably has a line width in the range of 3 to 30 μm, and the line pitch in the range of 50 to 500 μm. The opening ratio of the conductive mesh is preferably 70% or more, particularly preferably 80% or more. The upper limit of the aperture ratio is about 95%. Here, the opening ratio of the conductive mesh means an area ratio occupied by the opening portion in the projected area of the conductive mesh.

  The conductive mesh is preferably blackened. The blackening treatment can be performed by oxidation treatment or black printing. For example, the methods described in JP-A Nos. 10-41682 and 2005-317703 can be used. The blackening treatment is preferably performed on the surface and both side surfaces of the conductive mesh on the viewing side, and it is further preferable to blacken both surfaces and both side surfaces of the conductive mesh.

  The resin layer provided on the electromagnetic wave shielding layer as described above is a resin layer (functional layer) that provides at least one function selected from, for example, a hard coat function, an antireflection function, and an antiglare function.

  For example, a layer having a hard coat function (hard coat layer) is provided for preventing scratches, and is composed of an acrylic resin, a urethane resin, a melamine resin, an epoxy resin, an organic silicate compound, a silicone resin, or the like. be able to. In particular, silicone resins and acrylic resins are preferable in terms of hardness and durability. Further, in terms of curability, flexibility, and productivity, those made of an active energy ray-curable acrylic resin or a thermosetting acrylic resin are preferable. In the hard coat layer, various additives can be further blended as necessary within the range in which the effects of the present invention are not impaired. For example, stabilizers such as antioxidants, light stabilizers, ultraviolet absorbers, surfactants, leveling agents and antistatic agents can be used, and the silicone leveling agent has polydimethylsiloxane as a basic skeleton, Those having a polyoxyalkylene group added are preferred, and a dimethylpolysiloxane-polyoxyalkylene copolymer (for example, SH190 manufactured by Toray Dow Corning Co., Ltd.) is preferred.

  The hard coat layer can be provided with an antireflection function by forming a high refractive index layer. The high refractive index of the hard coat layer is obtained by adding ultra-fine particles of a metal or metal oxide having a high refractive index to the resin composition for forming the hard coat layer or including molecules and atoms of a high refractive index component. This is achieved by using a resin.

The ultrafine particles having a high refractive index preferably have a particle size of 5 to 50 nm and a refractive index of about 1.65 to 2.7. Specifically, for example, ZnO (refractive index 1.90) , TiO ₂ (refractive index 2.3 to 2.7), CeO ₂ (refractive index 1.95), Sb ₂ O ₅ (refractive index 1.71), SnO ₂ , ITO (refractive index 1.95), Y Fine powders such as ₂ O ₃ (refractive index 1.87), La ₂ O ₃ (refractive index 1.95), ZrO ₂ (refractive index 2.05), Al ₂ O ₃ (refractive index 1.63), and the like. It is done.

  Examples of molecules and atoms contained in the resin for improving the refractive index include halogen atoms other than F, S, N, and P atoms, and aromatic rings.

  And as a layer (antireflection layer) which has an antireflection function, what laminated two or more layers of a high-refractive-index layer and a low-refractive-index layer so that a low-refractive-index layer may become a visual recognition side can be used. The refractive index of the high refractive index layer is preferably in the range of 1.5 to 1.8, particularly preferably in the range of 1.6 to 1.7. The refractive index of the low refractive index layer is preferably in the range of 1.25 to 1.45, particularly preferably in the range of 1.3 to 1.4.

Materials for forming the high refractive index layer include those obtained by polymerizing and curing urethane (meth) acrylate, polyester (meth) acrylate, etc., or those obtained by crosslinking and curing a silicone-based, melamine-based, or epoxy-based crosslinkable resin material. And organic materials such as indium oxide containing titanium oxide as a main component, or inorganic materials such as Al ₂ O ₃ , MgO, and TiO ₂ . Among these, organic materials are preferable.

  The layer having an antiglare function (antiglare layer) prevents glare in the image, and a film having minute irregularities on the surface is preferably used. As the antiglare layer, for example, particles are dispersed in a thermosetting resin or a photocurable resin and coated and cured on a support, or a thermosetting resin or a photocurable resin is applied to the surface. For example, a material that is cured and pressed after a mold having a desired surface state to form irregularities is used. Therefore, for example, the antiglare function can be provided by setting the surface shape of the hard coat layer to a predetermined shape. By setting the surface roughness Ra, which is an index indicating the surface irregularity shape, to 0.01 to 0.1 μm, a preferable haze value (JISK 7136; 2000) of 0.5 to 20% can be realized.

  It is also a preferable aspect to use a layer having both an antireflection function and an antiglare function.

  Furthermore, an antifouling layer can be provided as the functional layer. The antifouling layer prevents the oily substance from adhering to the display laminate by touching it with a finger, or prevents dust and dirt in the atmosphere from adhering to them. It is a layer for facilitating the removal even if it adheres. As such an antifouling layer, for example, a fluorine coating agent, a silicone coating agent, a silicon / fluorine coating agent, or the like is used. The thickness of the antifouling layer is preferably in the range of 1 to 10 nm.

  In addition to the resin layer as described above, the workpiece preferably includes a layer that exhibits a near-infrared shielding function, a color tone adjustment function, or a visible light transmittance adjustment function.

  The layer exhibiting the near-infrared shielding function is preferably adjusted so that the maximum value of light transmittance in the wavelength range of 800 to 1100 nm is 15% or less.

  The layer that expresses the near-infrared shielding function may be a layer that absorbs or reflects near-infrared rays, for example, may be provided by providing a plastic film in which a near-infrared absorbing dye, pigment, or metal is kneaded, You may provide by coating and drying the coating material which disperse | distributed or melt | dissolved the near-infrared absorption pigment | dye, the pigment, and the metal in the resin binder. Or you may make the adhesive layer for affixing the laminated body for a display to a display contain the said near-infrared absorption pigment | dye, a pigment, and a metal.

  Examples of the near infrared absorbing dye include known dyes such as a phthalocyanine compound, an anthraquinone compound, a dithiol compound, and a diimonium compound.

  The layer that expresses the color tone adjustment function is a layer that absorbs light of a specific wavelength emitted from the display to improve color purity and adjust the color tone of the display, such as white balance, and a dye that absorbs light of a specific wavelength. You may provide the layer to contain separately, and may make the said pigment | dye contain in the layer which expresses the above-mentioned near-infrared shielding function, and the below-mentioned contact bonding layer.

  As the toning dye, for example, a phthalocyanine dye is known as a dye absorbing near 600 nm.

  In particular, it is preferable to shield orange light that lowers the color purity of red light emission, and it is preferable to contain a dye having an absorption maximum in a wavelength range of 580 to 620 nm. Furthermore, it is also preferable to contain a pigment having an absorption maximum at a wavelength of 480 to 500 nm.

  When providing the layer which expresses the near-infrared shielding function and the layer which expresses the color tone adjustment function described above, the layer is provided between the base film and the electromagnetic wave shielding layer or on the opposite side of the electromagnetic wave shielding layer with respect to the base film. And the latter is particularly preferred.

  The functional layer is preferably a single layer and has a plurality of functions. In particular, the present invention is a single functional layer in order to increase production efficiency because the resin layer is suitably used when a film formed by direct coating on an electromagnetic wave shielding layer is used as a workpiece. Is preferred. In this case, a single layer including at least a hard coat function is preferable.

  And in this invention, it is preferable that the film in which the resin layer was provided on the electromagnetic wave shielding layer has the cover film laminated | stacked on the resin layer for the purpose of the protection of the said resin layer and a connection part. In addition, it is preferable that a cover film is laminated | stacked so that the resin layer coating surface and the substantially whole surface of a connection part may be coat | covered, for example after resin layer coating.

Various plastic films can be used as the cover film. For example, polyester films such as polyethylene terephthalate, polyolefin films such as polyethylene film, polypropylene film, polybutylene film, polyacetyl cellulose film, polyacryl film, polycarbonate film, epoxy film, polyurethane film, etc. A film or a polyolefin film is preferably used.
Since the cover film is finally peeled off from the display filter, the cover film is laminated via a peelable adhesive or adhesive. However, an adhesive material or the like is not necessary when a film having adhesiveness alone is used as the cover film.

  Furthermore, when the workpiece is a PDP filter, it is preferable to provide an adhesive layer on the outermost surface of the base film opposite to the conductive mesh. Such an adhesive layer can be provided with the above-described near-infrared shielding function, color tone adjusting function, or visible light transmittance adjusting function. Moreover, it is a preferable aspect to provide the adhesive layer with an impact relaxation function for protecting the display from impact.

  The present invention is implemented using a film in which a resin layer is provided on the electromagnetic wave shielding layer as described above as a workpiece. Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. However, the contents of the present invention are not limited to the following embodiments.

  As shown in FIG. 1, for example, the laser processing apparatus of the present invention includes a laser oscillation tube 1 for generating laser light, a focus lens 8 for condensing the laser light on a film, and fixing the focus lens 8 together with the focus lens 8. A laser head or the like covering the periphery of the optical path of the laser light transmitted through the lens 8 is provided. The laser head includes an inner cylinder 10 (casing) provided with a laser light irradiation port 5, an air supply means such as an air supply port 7 for supplying air into the inner cylinder 10, An outer cylinder 9 and an exhaust port 6 for exhausting outside are provided. The inner cylinder 10 provided with the laser beam irradiation port 5 is arranged so as to face the film as the workpiece, and is arranged so that the laser beam irradiation port 5 is at least 10 mm away from the film as the workpiece. Established. Further, the air supply means to the inside of the inner cylinder 10 can set the pressure inside the inner cylinder 10 to a pressure of +0.02 MPa to +0.05 MPa with respect to the pressure of the atmosphere in which the film is arranged. is there.

  In the apparatus shown in FIG. 1, for the purpose of improving safety in the laser optical path between the laser oscillation tube 1 and the focus lens 8, a beam extension comprising a plurality of lenses is provided downstream of the laser oscillation tube 1. A panda 2 is arranged and configured to increase the beam diameter of the laser light. A bend mirror 4 that bends the optical path of the laser light is also arranged downstream of the beam expander 2.

  Hereinafter, each element constituting the apparatus of FIG. 1 will be described in detail.

(Laser tube 1)
The laser oscillation tube generates stimulated emission from the excited molecules inside the laser oscillation tube and induces laser oscillation.
Inside the laser oscillation tube, the laser medium is excited, and further, inversion distribution is taken out, and stimulated emission is taken out from the laser medium. The stimulated emission light is amplified and oscillated as laser light.

As the laser medium, YAG (Yttrium Aluminum Garnet), AlGaAs, sapphire, YVO ₄ , carbon dioxide (CO ₂ ), or the like can be used. In particular, when a PDP filter film is used as a workpiece, the processability for the resin layer and the protective film to be removed, and the resistance of the copper constituting the mesh that is desired to be exposed as it is without ablation Furthermore, it is preferable to use carbon dioxide gas (CO ₂ ) because of the large output obtained at a relatively low cost compared to other methods. The wavelength of the laser light depends on the laser medium. For example, the Nd: YAG laser using neodymium-added YAG is 1,064 nm, and the carbon dioxide laser is 10,600 nm. In addition to this, a different wavelength may be used by generating a harmonic with respect to the original wavelength.

  The transmission mode of the laser oscillation tube includes continuous and pulse transmission, and can be selected as necessary.

(Beam expander 2, bend mirror 4, focus lens 8)
The laser light extracted from the laser oscillation tube 1 is adjusted to a predetermined beam diameter by the beam expander 2 and then guided to the laser head. Since the focused laser beam has a very high energy density and is dangerous, and even if it is a laser beam, it shows a diffraction phenomenon when the beam diameter is small. Therefore, in the optical path for guiding the laser beam to the laser head, The beam diameter is preferably increased by the expander 2.

  Further, the bend mirror 4 allows the optical path to be bent through the bend mirror 4.

  The optical system such as the beam expander 2, the condensing lens 8, and the bend mirror 4 is preferably provided with a coating for preventing reflection as necessary. For example, in the case of an ultraviolet to infrared laser, calcium fluoride or the like is used as a coating material for preventing reflection.

  The laser beam guided to the laser head is condensed by the focus lens 8 inside the head and irradiated onto the workpiece. At this time, the focus lens 8 is used to change the laser focus position to an appropriate position with respect to the workpiece, that is, the focus state of the laser beam on the workpiece surface from just to defocus. It is possible to adjust the spread of the laser irradiation area. Thereby, a processing area can be made into a predetermined size. For example, when the focus position of the laser beam is exactly the workpiece surface position (just focus), the laser irradiation portion has the minimum area, and the processing trace is thin and extremely sharp. On the other hand, when the focus position of the laser beam is set above the workpiece (generally), the laser irradiation area is expanded compared to the irradiation at the just focus position, while the ablation is relative to the laser irradiation area. Since the processing trace is obtained according to the laser light intensity distribution, the upper side, which is the irradiation surface side, becomes wider as it goes to the bottom side due to the energy density reduction due to the diffusion of the laser light, and compared with the case of just focus. Wide trapezoidal shape.

  Furthermore, the processing width, depth, edge shape, and the like can be adjusted by combining the output of the laser beam irradiated to the focus position, the processing speed, and the laser oscillation method (pulse length).

Specifically, for example, the laser focus position is set to 15 mm above the surface of the workpiece, the laser output and the processing speed are set to 25% and 700 mm / second of the oscillation tube output, and pulse oscillation with an oscillation frequency of 25 kHz, respectively. Machining results can be obtained (laser head)
The laser head is provided with a focus lens 8 inside the head, and protects the focus lens 8 from the external environment. By introducing gas here, the inside of the laser head is kept at a positive pressure against the outside atmosphere. , Can prevent the intrusion of transpiration gas into the interior.

  Specifically, an inner cylinder 10 having a laser light irradiation port 5 that covers at least the focus lens and covers the periphery of the optical path of the laser light that has passed through the focus lens is disposed, and the inner cylinder 10 is provided by an air supply means. Introduce gas into the interior. At this time, in order to minimize the air flow injected from the inside of the inner cylinder 10 through the irradiation port 5, the inside of the inner cylinder 10 is +0.02 MPa to +0. The pressure is set to 05 MPa to prevent the invading gas from entering the inside.

  Furthermore, it is preferable that an outer cylinder 9 having an exhaust port 6 is provided on the outer peripheral portion of the inner cylinder 10 so that the outer cylinder 9 acts as an exhaust nozzle. By doing so, it is possible to suck and remove the vaporized gas generated from the workpiece along with the laser processing, and exhaust the vaporized gas so that it does not drift around the processing site. Such exhaust means need not be a single cylindrical body as long as the gas around the inner cylinder 10 can be sucked and exhausted. For example, a plurality of exhaust nozzles are arranged around the inner cylinder 10 at equal intervals. Also good. Further, it is desirable that the exhaust has a capability of sufficiently sucking and exhausting the transpiration gas within a certain time, but it is not preferable that the workpiece is deformed and moved on the suction / fixed stage by suction.

  Here, at the irradiation port 5, by setting the pressure as described above, an air flow from the inside of the inner cylinder 10 toward the outside is generated. For this reason, the diameter of the irradiation port 5 is set to the lower limit of the laser optical path diameter so that the inside of the inner cylinder 10 is kept in a pressurized state and the blowout flow from the irradiation port 5 is easily diffused immediately after the blowout when the flow rate is constant. In addition, it is desirable that the opening diameter is very close to the lower limit.

  In the present invention, the irradiation port 5 needs to be separated by a distance that allows the airflow from the irradiation port 5 to sufficiently diffuse so that the airflow from the irradiation port 5 does not directly hit the workpiece. Specifically, it is necessary to arrange the irradiation port 5 so as to be separated from the workpiece by 10 mm or more. The upper limit of the distance is preferably the upper limit of the focal length of the focus lens 8, and is preferably 170 mm or less when a commonly used focus lens is used, but the diameter of the irradiation port 5 is determined. Considering the diameter of the laser optical path, it is desirable that the diameter is further 100 mm or less.

  Further, in the present invention, as shown in FIG. 2, a plate-like member 13 is provided on the downstream side of the laser head and the upstream side of the workpiece with a gap between the laser head and the workpiece. It is preferable. The plate-like member 13 serves as a baffle plate against the airflow blown from the irradiation port 5 and has a minimum opening that can serve as a laser beam path. Since the air flow blown out from the irradiation port 5 starts to diffuse immediately after the blowing, the plate-like member 13 is provided at a distance from the irradiation port 5 so that the workpiece can be irradiated with laser light while shielding the diffused air flow. . That is, it is possible to prevent the airflow from being blown to the workpiece, and thus to prevent the vaporized gas from being blown to the workpiece. On the other hand, the transpiration gas generated from the workpiece becomes a diffusion flow above the workpiece and toward the celestial sphere, but is blocked by a plate provided in front of the nozzle opening and cannot reach the nozzle opening.

  It is desirable that the irradiation port 5 of the laser head and the plate-like member 13 be separated from each other so that the airflow is sufficiently diffused. Therefore, the distance from the irradiation port 5 is preferably 3 mm or more, and more preferably 5 mm or more. The size of the plate-like member 13 is not particularly limited, but is desirably 10 mm or more.

  Further, it is desirable that the hole diameter of the opening serving as the laser optical path provided in the plate-like member 13 is as close to the lower limit as possible with the laser optical path diameter being the lower limit.

  The laser head irradiation port 5, the plate-like member 13, and the like are preferably made of a material that is resistant to laser irradiation because there is a possibility that the laser is irradiated by an erroneous operation. For example, when used for a carbon dioxide laser, a material having high laser reflectivity such as gold, silver, copper, and aluminum is desirable, and copper is particularly desirable because of its high laser reflectivity and ease of processing.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples.

<Laser processing equipment>
The processing apparatus is basically the apparatus having the configuration shown in FIG. 1, and further includes a stage for sucking and fixing a film as a workpiece, and an arm capable of moving the laser head to an arbitrary position on the stage. ing. In addition, a processing controller that controls the laser output, processing speed, oscillation frequency, laser nozzle position, etc., transport means for carrying the film in and out of the processing equipment, prevention of leakage of laser light and prevention of external diffusion of vaporized gas. It also has an enclosure.

<Laser tube>
As the laser oscillation tube 1, a carbon dioxide laser oscillator SCx20 series manufactured by rofin was used. The laser wavelength is 10.6 μm. This was used in a pulse oscillation mode with an oscillation frequency of 25 kHz and a pulse width of 40 μs.

<Laser head>
The inner cylinder 10 for fixing the focus lens 8 is shaped like a cone on the downstream side in the laser light transmission direction from the focus lens 8, and an opening of φ10 mm is provided at the tip thereof to form an irradiation port 5.

  Compressed air can be introduced into the inner cylinder 10 from an air supply port 7 provided on the downstream side of the focus lens 8, so that a portion of the inner cylinder 10 that contacts the downstream side of the focus lens can be pressurized. I made it.

  Furthermore, the outer cylinder was provided concentrically so as to cover the outer periphery of the inner cylinder, and slits with a spacing of 3 mm were formed between the irradiation holes of the inner cylinder. This slit portion was used as an exhaust nozzle for sucking transpiration gas. The exhaust nozzle is connected to an exhaust fan in the outer cylinder of the laser head, and the vaporized gas sucked from the slit portion is exhausted to the outside of the processing apparatus via the exhaust fan.

<Workpiece>
As a workpiece, a film made of a base material, an electromagnetic shield layer, a resin layer, and a cover film obtained as follows was used.

<Base material>
As the substrate, a roll-shaped PET film (Lumirror (registered trademark) manufactured by Toray Industries, Inc.) having a thickness of 100 μm, a width of 1000 mm, and a length of 100 m was used.

<Formation of electromagnetic shielding layer>
A nickel layer (thickness: 0.02 μm) is formed by sputtering on the entire surface of the base material except for 10 mm each at both ends in the width direction, and a copper layer with a thickness of 2.5 μm is vacuumed thereon. It formed by the vapor deposition method. Next, an alkali development type high-sensitivity positive resist film was laminated on the surface of this copper layer, exposed using a semiconductor laser having a wavelength of 405 nm, and developed using a developer containing 1% by mass of sodium carbonate. Next, after etching with a ferric chloride solution, the resist layer is peeled off by treatment with a 3% by mass aqueous sodium hydroxide solution, and a continuous mesh pattern having a line width of 10 μm, a line pitch of 250 μm, and a thickness of 2.5 μm. A conductive mesh made of was formed over 980 mm in the width direction of the long base material and 90 m in the longitudinal direction. Subsequently, the conductive mesh was blackened using an oxidation treatment agent (adjusted at a ratio of Enplate MB-438A / B / pure water = 8/13/79 manufactured by Meltex Co., Ltd.).

<Coating of resin layer>
The following antiglare hard coat layer was applied as a functional layer on the conductive mesh of the PET film on which the conductive mesh was formed.

  The coating was performed using a slit die coater with a coating width of 960 mm.

<Anti-glare hard coat layer>
A commercially available hard coating agent (Opstar (registered trademark) Z7534 manufactured by JSR) was diluted with methyl ethyl ketone to a solid content concentration of 50% by mass, and acrylic fine particles having an average particle size of 1.5 μm (Chemisnow (Soken Chemicals) (Registered trademark) MX series) was added in an amount of 1% by mass based on the solid content of the hard coat agent to prepare a paint for an antiglare hard coat layer.
After coating the above-mentioned paint, it was dried at 80 ° C. and further irradiated with ultraviolet light 1.0 J / cm 2 to be cured, thereby providing an antiglare hard coat layer having a thickness of 6 μm.

<Lamination of cover film>
After forming a functional layer on the conductive mesh as described above, a cover film ("E-MASKIP300" manufactured by Nitto Denko Corporation) is laminated on a 38 μm PET film with a 5 μm slightly adhesive layer). It was laminated | stacked on the whole surface of the coating area | region and uncoated area | region.

<Lamination of near-infrared shielding layer>
On the surface opposite to the conductive mesh of the PET film, a paint in which an acrylic resin is mixed with a phthalocyanine dye and a diimonium dye as near-infrared absorbing dyes and a tetraazaporphyrin dye as an orange light absorbing dye is coated with a gravure coater. It was coated, dried and cured at 80 ° C., and a near infrared shielding layer having a dry thickness of 12 μm was provided.

<Lamination of adhesive layer>
The following adhesive layer was laminated on the near infrared shielding layer.

  The adhesive layer was previously laminated in a state sandwiched between separate films as described below, and was laminated on the near-infrared shielding layer by laminating one separate film while peeling off.

<Adhesive layer>
For the adhesive layer, UV curable urethane acrylate resin (Hybon (registered trademark) manufactured by Hitachi Chemical Polymer Co., Ltd.) is applied on a separate film by slit die coater, and then the coating film is cured using a UV irradiation device. Subsequently, a separate film was pasted to obtain an adhesive layer having a thickness of 300 μm sandwiched on the separate film.

Example 1
The workpiece was subjected to half-cut processing in which a carbon dioxide laser was irradiated linearly over a length of 500 mm to remove the cover film and the resin layer.

    At this time, the distance from the front end of the inner cylinder to the film is 12 mm, and the inner cylinder 10 is compressed air (pressure) so that the internal pressure is 0.05 MPa with respect to the atmospheric pressure at which the film is disposed. 0.05 MPa) was introduced. Moreover, the slit between the inner cylinder 10 and the outer cylinder 9 was made into the exhaust nozzle, and it exhausted at 3000 L / min. The introduction and exhaust of compressed air was performed only when the laser was oscillated and the film was being processed, and was stopped while the laser oscillation was not being processed. Further, the internal pressure of the inner cylinder 10 is measured with a pressure gauge (digital pressure switch ZSE30 / ISE30 series manufactured by SMC) provided near the air inlet 7 for measuring the gauge pressure, and the display value during laser processing is measured with the inner cylinder. An internal pressure of 10 was used. On the other hand, the pressure of the atmosphere in which the film is disposed was atmospheric pressure. The laser oscillation tube output was set to 25% of the maximum oscillation tube output, the processing speed was set to 700 mm / second, and the position where the laser beam focused was set to 15 mm above the film surface.

  After laser irradiation under the conditions as described above, when the vicinity of the half-cut mark of the film was observed, a bulge due to processing was seen on the processing edge part on the cover film, but adhesion such as dirt was observed. There wasn't. And when the cover film was peeled off and the surface of the resin layer was observed, no dirt was attached or raised by laser processing. Furthermore, when the inside of the inner cylinder 10 was observed from the irradiation port 5, adhesion of a transpiration was not recognized.

(Example 2)
Laser processing was performed in the same manner as in Example 1 except that the plate-like members 3 were provided at intervals as shown in FIG. The plate member 3 was an aluminum disk having a thickness of 0.5 mm and an outer dimension of 20 mmφ, and the distance from the irradiation port 5 was 10 mm. The plate-like member 3 was provided with an opening of φ0.8 mm as a laser optical path.

  When the vicinity of the half-cut mark of the film was observed after the half-cut processing, swell due to the processing was observed on the processing edge portion on the cover film, but no adhesion such as dirt was observed. Further, when the cover film was peeled off and the coating surface was observed, there was no contamination due to laser processing or coating swell. Moreover, when the inside of the inner cylinder 10 was observed from the irradiation port, adhesion of transpiration was not recognized.

(Comparative Example 1)
Laser processing was performed in the same manner as in Example 1 except that compressed air was not introduced and exhausted.

  However, during laser processing, it was observed that the vaporized gas generated during laser processing drifted in the vicinity of the irradiated part. Further, in the vicinity of the apparatus, an unpleasant odor considered to be caused by ablation that was not observed in Examples 1 and 2 was confirmed.

  And when the half cut trace vicinity of the film was observed, the appearance that the transpiration material adhered to the peripheral cover film of the half cut part and it became whitish was seen. Although wiping was attempted using a wiping cloth, most of the wiping cloth could not be removed.

  Moreover, when the inside of the inner cylinder 10 was observed, adhesion of the powder which is the solidified product of the transpiration material was recognized in the vicinity of the irradiation port.

(Comparative Example 2)
Laser processing was performed in the same manner as in Example 1 except that the pressure inside the inner cylinder 10 was set to 0.07 MPa with respect to the atmospheric pressure.

  However, when the vicinity of the half-cut mark of the film was observed after the half-cut processing, a portion of the peripheral cover film of the half-cut portion was found to be whitish due to a transpiration material adhering in a range of about 1 mm around the half-cut portion. It was seen in some places. Although wiping with a wiping cloth was attempted, almost all but one part could not be removed.

  On the other hand, when the inside of the inner cylinder 10 was observed from the irradiation port 5, adhesion of transpiration was not observed.

(Comparative Example 3)
Laser processing was performed in the same manner as in Example 1 except that the pressure inside the inner cylinder 10 was made as close to 0 as possible with respect to the atmospheric pressure (actually, it fluctuated in the range of 0 to 0.01 MPa).

  After the half-cut processing, when the vicinity of the half-cut mark of the film was observed, no adhesion of transpiration was observed on the peripheral cover film of the half-cut portion. However, when the inside of the inner cylinder 10 was observed from the irradiation port 5, adhesion of the transpiration powder was observed.

(Comparative Example 4)
A 8.5 mm long truncated cone-shaped copper nozzle is added to the irradiation port 5, the distance from the copper nozzle tip to the film is 4.5 mm, and the pressure inside the inner cylinder 10 is 0.02 MPa with respect to the atmospheric pressure. Except that, laser processing was performed in the same manner as in Example 1.

  However, when the vicinity of the half-cut mark of the film was observed after the half-cut processing, the portion of the cover film around the half-cut portion was whitish due to the transpiration material adhering in a narrow range of about 1 mm around the half-cut portion. Was seen extensively. Although wiping with a wiping cloth was attempted, almost all but one part could not be removed.

  In both Examples and Comparative Examples, the processed film after laser irradiation had the cover film and the resin layer ablated in a range of length 500 mm × width 500 μm. In this portion, in the depth direction, the cover film and the resin layer were ablated over the entire thickness, and the PET film in contact with the resin layer was ablated for a depth of 10 μm, and a desired half-cut process was achieved.

It is a schematic diagram of the laser processing apparatus which shows one Embodiment of this invention. It is a schematic diagram of the laser processing apparatus which shows other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser oscillation tube 2 Condensing beam expander 3 Laser optical path 4 Bend mirror 5 Irradiation port 6 Exhaust port 7 Air supply port 8 Focus lens 9 Outer cylinder (laser head)
10 Inner cylinder (laser head)
12 Workpiece 13 Plate member

Claims (4)

  When a part of the film in the thickness direction is removed by condensing and irradiating a laser beam on a film with a resin layer on the electromagnetic wave shielding layer, a laser is passed around the optical path of the laser beam that has passed through the lens. Covered with a casing with a light irradiation port, the irradiation port is separated from the film by at least 10 mm, and the vaporized gas is exhausted outside the casing while supplying air to the inside of the casing. A laser processing method in which the pressure is +0.02 MPa to +0.05 MPa with respect to the pressure of the arranged atmosphere.   A laser processing apparatus for irradiating a film having a resin layer on an electromagnetic wave shielding layer with laser light and removing a part of the film in the thickness direction, a laser oscillator for generating laser light, and a laser light film A lens for condensing the lens, a casing having a laser beam irradiation port for fixing the lens and surrounding the optical path of the laser beam transmitted through the lens, a means for supplying air into the casing, and a vaporized gas outside the casing And a casing is disposed such that the laser light irradiation port is at least 10 mm away from the film.   Furthermore, the laser processing apparatus of Claim 2 which provides the plate-shaped member which has the opening used as a laser beam path between the irradiation port of a laser beam, and a film.   Production of a PDP filter for removing a resin layer by irradiating a film having a resin layer on an electromagnetic wave shielding layer with a laser according to the method according to claim 1 or the apparatus according to claim 2 or 3. Method.

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