Optical processing device and optical processing method

Abstract

To provide an optical processing apparatus that has high processing performance, and can perform homogeneous surface modification.SOLUTION: An optical processing apparatus comprises: at least one light source which irradiates ultraviolet light that belongs to a wavelength band of 205 nm or less; a lamp house which covers the at least one light source, and has an opening in an emitting direction of the ultraviolet light; a conveying body which conveys material to be processed in one direction so as to cross a position opposing the opening while keeping a gap from the lamp house; a heater which is arranged downstream the lamp house, and raises the temperature of the conveying body; and a control part which performs control so as to convey the material to be processed while irradiating the material to be processed with the ultraviolet light, where the control part controls the heater to raise the temperature of the conveying body so as to suppress temperature drop of the conveying body whose temperature risen by the at least one light source.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical processing device and an optical processing method. [Background technology]

[0002] There is known a surface modification method in which the surface of a material to be treated is irradiated with ultraviolet light to modify the surface. For example, Patent Document 1 describes a surface modification method in which the surface of a fluororesin is modified by irradiating the surface with ultraviolet light while supplying a treatment gas to the surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 024882 Summary of the Invention [Problem to be solved by the invention]

[0004] As surface modification technology using ultraviolet light advances, there is a demand for improvements in light treatment equipment. The present invention aims to provide a light treatment equipment and a light treatment method that have high processing capacity and can perform uniform surface modification. [Means for solving the problem]

[0005] The light treatment device of the present invention comprises at least one light source that irradiates ultraviolet light belonging to a wavelength band of 205 nm or less; a lamp house that covers the at least one light source and has an opening in a direction in which the ultraviolet light is emitted; a conveying body that conveys the material to be treated in one direction so as to cross a position facing the opening while leaving a gap between the conveying body and the lamp house; a heater disposed downstream of the lamp house and configured to heat the conveying body; a control unit that controls the transport of the workpiece while irradiating the workpiece with the ultraviolet light, The control unit controls the heater to increase the temperature of the transport body so as to suppress a decrease in the temperature of the transport body, which has been increased by the light source.

[0006] Ultraviolet light in the wavelength range of 205 nm or less is called vacuum ultraviolet (VUV) light. Ultraviolet light in this wavelength range generates oxygen radicals and ozone from oxygen molecules in the environment. The oxygen radicals and ozone react with the surface of the material to be treated and have the ability to modify the surface. On the other hand, ultraviolet light in the wavelength range of 205 nm or less has a high optical absorption by oxygen molecules. The material to be treated is moved by a conveyor across a position opposite the opening of the lamp house.

[0007] The position facing the opening of the lamp house is the position directly below the lamp house where the light emitted from the light source arranged inside the lamp house reaches. The material to be treated is passed across the position where the light emitted from the light source arranged inside the lamp house reaches. This allows the material to be modified continuously, and the modification process to be carried out over a large area in a short time. The "transport body" is a transport means for placing the material to be treated and moving it. Details will be described later, but specific examples of the "transport body" include a belt conveyor and a movable stage.

[0008] The light source emits not only ultraviolet light in the wavelength band of 205 nm or less, but also infrared light. In the position facing the lamp house opening, i.e., directly below the lamp house, the temperature of the carrier rises due to the optical energy of the infrared light. On the other hand, outside the position directly below the lamp house where the infrared light does not reach, the carrier is not affected by the infrared light.

[0009] The inventors realized that the conveying body may bend when it is transported from inside the lamp house to outside. This is because when part of the conveying body is located directly below the lamp house and the other part is located outside the lamp house, temperature variations occur inside the conveying body, and bending occurs due to differences in thermal expansion. When bending occurs in the conveying body, the distance between the light source and the material to be treated changes, making it impossible to pass the conveying body in one direction while maintaining a constant distance from the light source, and the desired modification treatment cannot be performed uniformly.

[0010] Therefore, the inventors have positioned a heater downstream of the lamp house to heat the transported body as it leaves the lamp house. This reduces temperature variations within the transported body and minimizes deflection due to differences in thermal expansion, even when part of the transported body is located directly below the lamp house and the rest is located outside the lamp house. As a result, the transported body can pass in one direction while maintaining a distance from the light source, allowing the desired modification process to be performed uniformly.

[0011] The conveying body may be an endless belt stretched between a first pulley arranged upstream of the lamp house and a second pulley arranged downstream of the lamp house.

[0012] The heater may radiate infrared rays toward the conveying body.

[0013] The heater may inject a heated fluid toward the conveying body.

[0014] The heater may indirectly increase the temperature of the endless belt by increasing the temperature of the surface of the second pulley.

[0015] The light treatment device may further include a second heater disposed upstream of the lamp house for heating the conveyor, thereby reducing deflection and maintaining a better distance between the light source and the material to be treated.

[0016] The light processing device may further include an exhaust chamber at least either upstream of the lamp house or downstream of the lamp house, which makes it easier to control the oxygen concentration and humidity inside the lamp house.

[0017] The endless belt may be mainly made of stainless steel, which has high corrosion resistance against ultraviolet light. The endless belt may have through holes that penetrate the endless belt in the thickness direction.

[0018] The optical processing device may further include a guide roller facing the opening, and the endless belt may be sandwiched between the opening and the guide roller. The guide roller may be made of metal or resin. The guide roller may be divided in the width direction.

[0019] The optical processing device may further include a sensor for measuring the temperature of the transport body before or after the temperature is increased by the heater, or the amount of heat radiated by the heater. The control unit may control the heater based on the temperature result obtained from the sensor.

[0020] The optical treatment method of the present invention comprises conveying a material having a resin on its surface in one direction by a conveying body, irradiating the material with ultraviolet light in a wavelength band of 205 nm or less emitted from a light source in a lamp house where oxygen is present, The material to be treated that has been carried out of the lamp house is heated to a temperature of the conveying body so as to prevent a decrease in the temperature of the conveying body that has been heated by the light source. [Effects of the Invention]

[0021] It is possible to provide an optical treatment device and an optical treatment method that have high treatment capacity and can perform uniform surface modification. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram illustrating a first embodiment of an optical processing device. [Figure 2] FIG. 2 is an enlarged view of the area from the rear portion of the lamp house to the second pulley. [Figure 3] 1A and 1B are diagrams showing the surface of a workpiece before surface modification and the surface of the workpiece after surface modification. [Figure 4] FIG. 4 is a diagram showing the shape of a first pulley. [Figure 5] FIG. 3 is a diagram showing a guide roller according to the present embodiment. [Figure 6] FIG. 10 is a diagram illustrating a second embodiment of the optical processing device. [Figure 7] 7 is an enlarged view of the area from the first pulley to the front part of the lamp house in FIG. 6. FIG. [Figure 8] FIG. 10 is a diagram illustrating a third embodiment of the light processing device. DETAILED DESCRIPTION OF THE INVENTION

[0023] The embodiments will be described with reference to the drawings. Note that the drawings disclosed in this specification are merely schematic illustrations. That is, the dimensional ratios on the drawings do not necessarily match the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily match.

[0024] In the following, each drawing will be described with reference to the XYZ coordinate system. In this specification, when a direction is expressed and a distinction is made between positive and negative directions, it is described with a positive or negative sign, such as "+X direction" and "-X direction." When a direction is expressed without distinguishing between positive and negative directions, it is simply described as "X direction." In other words, in this specification, when simply referring to "X direction," it includes both "+X direction" and "-X direction." The same applies to the Y direction and the Z direction. In the embodiments described below, the direction of gravity is the -Z direction, the conveying direction in which the workpiece is conveyed on the conveying body is the +Y direction, and the width direction of the workpiece is the X direction.

[0025] First Embodiment [Outline of optical processing equipment] A first embodiment of a light treatment device is shown in Figure 1. The light treatment device 100 includes three light sources 3 that irradiate ultraviolet light in a wavelength band of 205 nm or less, a lamp house 2 that is arranged to cover the three light sources 3, and a carrier that carries a material to be treated 4. As will be described in detail later, in this embodiment, a conveyor belt 1 (hereinafter sometimes simply referred to as "belt 1") is used as the carrier.

[0026] The ultraviolet light L1 emitted by the light source 3 is vacuum ultraviolet light, more specifically, ultraviolet light belonging to a wavelength band of at least 205 nm or less. As used herein, "ultraviolet light belonging to a wavelength band of at least 205 nm or less" refers to light that exhibits an emission intensity at least at 205 nm or less in the emission spectrum of the light source 3. Such light includes, for example, (1) light that exhibits an emission spectrum that exhibits intensity over a broad wavelength band and has a peak emission wavelength of at most 205 nm or less, (2) light that exhibits an emission spectrum that exhibits multiple maximum intensities (multiple peaks), with any one of the multiple peaks being within the wavelength range of at most 205 nm, and (3) light in which light at 205 nm or less accounts for at least 30% of the total integrated intensity in the emission spectrum.

[0027] In this embodiment, the inner wall of the lamp house 2 has a plurality of gas supply ports 8 for supplying an inert gas. The plurality of gas supply ports 8 are connected to a gas supply source 9. In this embodiment, nitrogen is used as the inert gas. Nitrogen is supplied from the gas supply source 9 to the gas supply ports 8, and then blown out from the gas supply ports 8 into the lamp house 2. As will be described in detail later, this reduces the oxygen concentration inside the lamp house 2. Note that the oxygen concentration inside the lamp house 2 can also be reduced by, for example, placing the lamp house 2 itself in an environment with a large amount of inert gas. Therefore, the gas supply ports 8 provided inside the lamp house 2 are not an essential component of the present invention.

[0028] The opening of the lamp house 2 is located close to the belt 1. The optical processing device 100 has an exhaust space forming device 5 and an exhaust port 24 on the opposite side of the belt 1 from the opening of the lamp house 2. Most of the inert gas supplied from the gas supply port 8 flows around the belt 1, is collected in the exhaust space forming device 5, and is exhausted from the exhaust port 24.

[0029] In this embodiment, the belt 1 is endless because it is circular. The belt 1 is stretched between a first pulley 11 positioned relatively in the -Y direction and a second pulley 12 positioned relatively in the +Y direction. The belt 1 moves the material 4 to cross a position facing the opening of the lamp house 2 while leaving a gap between the belt 1 and the lamp house 2.

[0030] Positions Y1 and Y2 are located above (on the +Z side of) the belt 1. Position Y1 is located upstream (on the -Y side) of the lamp house 2 and position Y2. Position Y2 is located downstream (on the +Y side) of position Y1 and the lamp house 2. At position Y1, the material 4 to be treated is placed on a portion of the belt 1, and the placed material 4 to be treated moves downstream (in the +Y direction) together with the portion of the belt 1. The material 4 to be treated is modified just below the lamp house 2, and the material 4 to be treated is released from the belt 1 at position Y2. The material 4 to be treated may be placed on the belt 1 or released from the belt 1 by a handling robot or another conveyor belt (not shown).

[0031] The light processing device 100 has a plurality of guide rollers 13 that support the belt 1 between the first pulley 11 and the second pulley 12. In order to reduce fluctuations in the gap between the light source 3 and the material 4 to be processed, it is preferable to arrange a large number of guide rollers 13, particularly near the light source 3. In this embodiment, six guide rollers 13 are provided below the opening of the lamp house 2. The light processing device 100 also has a dancer roller 14 that applies a constant tension to the belt 1.

[0032] [Heating device] The optical processing device 100 has a heater that heats the belt 1 located downstream of the lamp house 2. In this embodiment, the heater is a heater 21 built into the second pulley 12 and a heating gas supply unit 22. The heater 21 built into the second pulley 12 located downstream of the lamp house 2 heats the surface of the second pulley 12. This heats the belt 1 that is in contact with the second pulley 12.

[0033] Heating gas 23 is blown from the heating gas supply unit 22 toward the belt 1. This heats the belt 1 downstream of the lamp house 2. The material 4 to be treated may be present between the heating gas supply unit 22 and the belt 1. By raising the temperature of the material 4 to be treated, the temperature of the belt 1 can be raised indirectly. The same applies when the material 4 to be treated is present between the belt 1 and a heater other than the heating gas supply unit 22 (details will be described later).

[0034] The operation of the heaters (21, 22) will be described with reference to FIG. 2. FIG. 2 is an enlarged view of the area from the rear portion of the lamp house 2 to the second pulley 12 in FIG. 1. However, FIG. 2 shows a state in which the heaters (21, 22) are not operating. That is, the second pulley 12 is not heated, and the heating gas supply unit 22 does not blow heating gas 23 onto the belt 1. With the heaters (21, 22) not operating, the light source 3 is turned on, and ultraviolet light L1 is irradiated onto the belt 1. As a result, as shown in FIG. 2, the belt 1 may develop a wavy deflection D1, which has periodic bulges in the +Z direction in the Y direction. In FIG. 2, the dashed-dotted line 25 tangent to the guide roller 13 indicates the position of the belt 1 when there is no deflection D1.

[0035] This deflection D1 is presumed to occur based on the following mechanism. First, the light source 3 emits not only ultraviolet light L1 in the wavelength band of 205 nm or less, but also infrared light. When the light source 3 is turned on, the infrared light heats the belt 1 directly below the lamp house 2, causing the belt 1 to expand. The expansion of the belt 1 occurs in the length, width, and thickness directions of the belt 1. Next, when the heated belt 1 leaves the lamp house 2 and runs for a while, the belt 1 is naturally cooled, and the expanded belt 1 contracts. In other words, a thermal expansion difference occurs within the belt 1.

[0036] Between the first pulley 11 and the second pulley 12, the belt 1 moves at a constant speed. Therefore, if a difference in thermal expansion occurs inside the belt 1 moving at a constant speed, a wavy deflection D1 appears in the belt 1. Note that while FIG. 2 only shows the deflection D1 appearing in the YZ plane of the belt 1, the belt 1 also deflects in the width direction (X direction). The magnitude of such deflection can reach 3 mm in the +Z direction relative to the position of the dashed dotted line 25 when there is no deflection. Note that when the optical processing device 100 is in an environment of room temperature (approximately 20°C), the belt 1 near the light source 3 is heated by the light source 3 when it is turned on, and the surface of the belt 1 can reach 50°C.

[0037] The wavy deflection D1 of the belt 1 narrows the gap between the material 4 to be treated and the light source 3. If the gap between the light source 3 and the material 4 to be treated becomes too narrow, the desired modification process cannot be performed uniformly. Furthermore, if the deflection D1 of the belt 1 becomes particularly large, the material 4 to be treated placed on the belt 1 may interfere with the light source 3 or with the lamp house 2 when being transported out of the lamp house 2.

[0038] Therefore, the inventors decided to use heaters (21, 22) to raise the temperature of the belt 1 so that the temperature of the heated belt 1 does not decrease after it leaves the lamp house 2. This allows the thermal expansion of the belt 1 to continue from the lamp house 2 to the second pulley 12, thereby suppressing variations in the thermal expansion of the belt 1. As a result, the wavy deflection D1 becomes smaller, and the position of the belt 1 approaches the dashed-dotted line 25 or overlaps with the dashed-dotted line 25. This maintains the distance between the light source 3 and the material 4 to perform the desired modification treatment uniformly.

[0039] [Heater control] As shown in FIG. 1, the light treatment device 100 includes a control unit 19 that controls the heaters (21, 22). The control unit 19 controls the heaters (21, 22) to heat them to a desired temperature. In this embodiment, the light treatment device 100 includes a temperature sensor 18. The temperature sensor 18 is located downstream of the lamp house 2 and upstream of the heaters (21, 22). The temperature sensor 18 is used to detect the temperature of the belt 1 at a position downstream of the lamp house 2 and upstream of the heaters (21, 22). In this embodiment, a sensor (radiation thermometer) that detects the amount of radiant heat from the belt 1 is used as the temperature sensor 18. This allows the temperature of the moving belt 1 to be detected in a non-contact manner.

[0040] Fig. 1 shows how the heaters (21, 22), temperature sensor 18, and control unit 19 are connected by power lines. The temperature sensor 18 measures the temperature of the belt 1 before or after it is heated by the heaters (21, 22). An electric signal detected by the temperature sensor 18 is sent to the control unit 19, which can determine the output of the heaters (21, 22) based on the detected temperature. Note that the power lines are omitted from Fig. 2.

[0041] Furthermore, instead of controlling the temperature using the control unit 19 shared with the other heaters (21, 22), individual temperature sensors may be attached to the heaters (21, 22). The heaters (21, 22) may be controlled based on detection signals from the individual temperature sensors. The temperature sensors may be thermocouples, resistance thermometers, or the like.

[0042] Note that not all power lines (electrical communication lines) are shown in Fig. 1. The control unit 19 may perform operation control of the optical processing device 100 (for example, drive control of the first pulley 11, lighting control of the light source 3, and control of the supply amount of inert gas).

[0043] The control unit 19 may be a dedicated control unit provided for the optical processing device 100, or may be a control unit shared with other devices or systems. The control unit may be a programmable logic controller (or sequencer), a personal computer, or a general-purpose computer.

[0044] Although the heaters in this embodiment are described as the heater 21 and the heated gas supply unit 22 built into the second pulley 12, the present invention is not limited to this. The heaters (21, 22) may be heaters separate from the second pulley 12, for example. In addition, infrared radiation heaters may be used as the heaters (21, 22). Furthermore, although the present embodiment includes two heaters (21, 22), it is sufficient to include at least one heater.

[0045] After a partial region of the belt 1 passes around the second pulley 12, the partial region of the belt 1 returns toward the first pulley 11. At this time, the partial region of the belt 1 is naturally cooled. Therefore, even after the circular belt 1 has made one revolution around the first pulley 11 and the second pulley 12, the belt 1 needs to be heated by a heater.

[0046] A method for determining whether the heaters (21, 22) are preventing a drop in the temperature of the belt 1 will be described. The temperature of the belt 1 is measured both when the heaters (21, 22) are operating and when the heaters (21, 22) are not operating. If the temperature of the belt 1 when the heaters (21, 22) are operating is higher than the temperature of the belt 1 when the heaters (21, 22) are not operating, it is confirmed that the heaters (21, 22) are preventing a drop in the temperature of the belt 1.

[0047] [Material to be treated] The material 4 to be treated used in this embodiment is a resin sheet called a prepreg, which is made by impregnating a base material such as paper or glass with a resin. An interlayer insulating film is formed from a copper-clad laminate (CCL) that is formed by bonding copper foil to the resin sheet and curing it. Interlayer insulating films are used for high-frequency circuit boards and the like. When bonding copper foil to the resin sheet, the above-mentioned surface modification treatment is used to increase the bonding strength of the resin sheet to the copper foil.

[0048] Materials other than resin sheets can also be used for the material to be treated 4. Modification treatment can also be performed for purposes other than improving bonding strength. The material to be treated 4 may alternatively be a thick, rigid plate-like substrate, a long flexible film, or a three-dimensional shape that is not plate-like. The length of the material to be treated 4 in the Y direction may be shorter or longer than the length of the lamp house 2 in the Y direction. The width of the material to be treated 4 in the X direction is shorter than the width of the lamp house 2 in the X direction.

[0049] [Modification mechanism] The mechanism of surface modification in this embodiment will be described. The ultraviolet light hν used in this embodiment, which belongs to a wavelength band of at least 205 nm or less, reacts with oxygen molecules in the environment to generate atomic oxygen. O( 1 D) is a highly reactive atomic oxygen (oxygen radical) and has an oxidizing effect. O( 3 P) represents the ground state of atomic oxygen, which is shown in equation (1). hν+O2→ O( 1 D)+O( 3 P) ···(1)

[0050] Ground state atomic oxygen, O( 3 P) combines with oxygen molecules in the presence of a third body M to produce ozone (O3), which is shown in equation (2). Ozone has an oxidizing effect. O( 3 P) + O2 + M → O3 + M (2)

[0051] Water vapor contained in the air also generates hydroxyl radicals (·OH), which have oxidizing properties, according to the following equations (3) and (4): hν+H2O → OH+H (3) O( 1 D) + H2O → 2( OH) ··· (4)

[0052] FIG. 3 is a diagram showing a schematic view of the surface of a prepreg, which is a material to be treated 4. The material to be treated 4a represents the surface of a resin sheet before modification treatment. Hydrocarbon groups are exposed on the surface of the resin sheet. In this embodiment, only a portion of the hydrocarbons in the polymer exposed on the surface of the resin sheet is shown in a simplified manner. Such a surface exhibits hydrophobicity.

[0053] The treated material 4b represents the surface of the prepreg after the modification treatment. Oxygen radicals (O( 1 D), ozone (O3), or hydroxyl radicals (·OH) oxidize hydrocarbon groups on the resin surface, generating hydroxyl and carboxyl groups. Hydrophilic hydroxyl and carboxyl groups improve bonding with copper.

[0054] [Oxygen concentration] Oxygen molecules are O( 1 However, in the vicinity of the surface of the treated material 4b, O( 1 In order to allow ultraviolet light hν, which is easily absorbed by oxygen molecules, to reach the surface, the oxygen concentration must be reduced to reduce the number of oxygen molecules in the light path. To achieve this, the lamp house 2 is filled with an inert gas.

[0055] The oxygen concentration in the lamp house 2 is preferably 10% or less, and more preferably 5% or less. For example, when 172 nm ultraviolet light travels 4 mm through a space where the oxygen concentration is 10% or less, a light intensity of 50% or more can be ensured, and when 172 nm ultraviolet light travels 4 mm through a space where the oxygen concentration is 5% or less, a light intensity of 70% or more can be ensured. However, as mentioned above, oxygen molecules are O( 1Since it is a raw material for producing D) or O3, in order to ensure oxygen molecules as a raw material, the oxygen concentration is preferably 1% or more, and more preferably 3% or more.

[0056] Oxygen radical (O( 1 The source of oxygen molecules and water molecules for obtaining oxygen radicals (O), ozone (O), or hydroxyl radicals (·OH) is the air outside the lamp house 2. As shown in FIGS. 1 and 2, there is a gap between the lamp house 2 and the belt 1. This gap is, for example, 3 to 4 mm. Oxygen molecules and water molecules flow into the lamp house 2 from outside the lamp house 2 through the gap between the lamp house 2 and the belt 1. In order to adjust the oxygen concentration inside the lamp house 2, it is advisable to control at least one of the amount of inert gas supplied from the gas supply port 8, the gas suction force from the exhaust port 24, and the gap between the lamp house 2 and the belt 1.

[0057] [Transport body] The belt 1, which is a conveying body, is mainly made of stainless steel. Stainless steel has a high resistance to oxygen radicals (O( 1 D)), ozone (O3), or hydroxyl radical (·OH). Belt 1 may be made of other metals or resins.

[0058] The belt 1 of this embodiment is sheet-shaped. The width of the belt 1 in the X direction is larger than the width of the material 4 to be treated in the X direction. The width of the belt 1 in the X direction is preferably 380 mm or more and 580 mm or less. The thickness of the belt 1 in the Z direction is preferably 0.1 mm or more and 0.5 mm or less. If the belt 1 is thick, it is less likely to be heated and to bend. On the other hand, if the belt 1 is thin, it is easier to move the belt 1 smoothly. The moving speed of the belt 1 is preferably 1 m / min to 5 m / min.

[0059] The belt 1 may have a plurality of through holes in the thickness direction of the belt 1. By having a plurality of through holes in the belt 1, part of the gas flowing from the lamp house 2 toward the exhaust space forming device 5 passes through the through holes without going around the belt 1. The through holes have the effect of suppressing turbulent gas flow. Furthermore, if the light processing device 100 has an adsorbent that adsorbs the material 4 to be processed through the through holes, the material 4 to be processed can be adsorbed and fixed to the belt 1. The adsorbent may be, for example, a suction mechanism that sucks the through holes.

[0060] [light source] In this embodiment, a xenon excimer lamp is used as the light source 3. A xenon excimer lamp is a discharge lamp in which xenon gas is sealed inside the arc tube. The peak emission wavelength of a xenon excimer lamp is 172 nm. The light source 3 may be a discharge lamp in which a gas other than xenon gas is sealed. The light source 3 may also be a solid-state light source such as an LED.

[0061] 1, three light sources 3 are arranged side by side in the Y direction, but it is sufficient to have at least one light source 3. Furthermore, the light sources 3 may be arranged side by side in the X direction, or the light sources 3 may be arranged side by side in both the X direction and the Y direction.

[0062] The width of the light source 3 in the X direction is preferably larger than the width of the material 4 in the X direction. The width of the light source 3 in the X direction is preferably, for example, 380 to 580 mm.

[0063] [Lamp House] The lamp house 2, which is arranged to cover the light source 3, has an opening in the direction (-Z direction) in which the ultraviolet light emitted by the light source 3 is emitted. This directs the light emitted from the light source 3 in the -Z direction. A reflector or reflective layer that reflects ultraviolet light may be formed on the inner wall of the lamp house 2.

[0064] The length of the lamp house 2 in the Y direction may be, for example, 300 mm to 500 mm. The distance in the Y direction between the end of the lamp house 2 on the +Y side and the center of rotation of the second pulley 12 may be, for example, 300 mm to 500 mm.

[0065] [Pulley] FIG. 4 shows the shape of the first pulley 11. In this embodiment, the first pulley 11 is a drive pulley for driving the belt 1. The first pulley 11 is a rotating body centered on an X1 axis extending in the X direction. The first pulley 11 has a crown shape in which a diameter R1 at the center in the X direction is slightly larger than a diameter R2 at an end in the X direction. The crown (radius of curvature) R3 of the first pulley 11 is preferably 100,000 mm or more, for example. The diameter R1 may be, for example, 50 mm to 170 mm. The shape of the first pulley 11 is not limited to this embodiment, and the first pulley 11 may have a cylindrical shape with a constant diameter in the X direction. The width direction length W1 of the first pulley 11 is larger than the width of the belt 1 in the X direction. The width direction length W1 of the first pulley 11 is preferably 400 mm to 600 mm.

[0066] The second pulley 12 is a driven pulley that moves due to friction with the driven belt 1. The shape and dimensions of the second pulley 12 may be the same as or different from the shape and dimensions of the first pulley 11. The distance between the rotation center of the first pulley 11 and the rotation center of the second pulley 12 may be 800 mm to 1200 mm. Note that the first pulley 11 may be the driven pulley and the second pulley 12 may be the driving pulley.

[0067] [Guide roller] FIG. 5 shows one of the guide rollers 13 of this embodiment. The guide roller 13 is used to support the belt 1 and move the belt 1 while reducing frictional resistance. The guide roller 13 is divided in the width direction. That is, it is configured with a plurality of small rollers 43 (only one small roller 43 is marked with a reference numeral in FIG. 5) lined up in the X direction. This reduces the contact area between the guide roller 13 and the belt 1, reduces the amount of heat transferred in both directions between the belt 1 and the guide roller 13, and makes it less likely that the belt 1 will be affected by the heat of the guide roller 13.

[0068] The guide roller 13 may be made of metal or resin. When the guide roller 13 is mainly made of a material with high thermal conductivity such as metal, it is particularly effective to use multiple small rollers 43. When using resin for the guide roller 13, it is preferable to use a resin that is resistant to deterioration by ultraviolet light (for example, polyimide resin, epoxy resin, or PTFE resin).

[0069] The shapes and dimensions of the multiple small rollers 43 are exemplified below. The multiple small rollers 43 are all rotating bodies centered on the X1 axis along the X direction. The diameter R3 of the small rollers 43 should be 50 mm to 150 mm. The width W2 of the small rollers 43 should be 20 mm to 100 mm. It is preferable that 2 to 20 small rollers 43 are lined up in the X direction.

[0070] The guide roller 13 may be configured as a single roller that is not divided in the width direction. The guide roller 13 may also be provided with a temperature adjustment element that enables adjustment of the temperature of the belt 1. The temperature adjustment element may include at least one of a heating element and a cooling element.

[0071] Although the optical processing device 100 of this embodiment does not have a guide roller outside the lamp house 2, it may have a guide roller outside the lamp house 2.

[0072] [Warm-up] Immediately after the light source 3 is turned on, the first pulley 11 and the second pulley 12 are at room temperature. Therefore, deflection D1 of the belt 1 is particularly likely to occur immediately after the light source 3 is turned on. As time passes after the light source 3 is turned on, the temperature of the members in contact with the belt 1, such as the second pulley 12, increases, and deflection D1 becomes smaller. Therefore, the light treatment device 100 may be warmed up. Warming up means operating the light treatment device 100 (i.e., turning on the light source 3 and rotating the belt 1 while operating the heater) before actually placing the material 4 to be treated on the belt 1 and starting the modification treatment. This causes the temperature of the belt 1 to increase, thereby preventing deflection D1 of the belt 1 from occurring. The warming up may be performed for, for example, 5 to 15 minutes.

[0073] Second Embodiment A second embodiment of the optical processing device will be described with reference to Fig. 6. The following description will focus on features that are different from the first embodiment. Points not described in the second embodiment can be implemented in the same way as the first embodiment. The same applies to a third embodiment described later.

[0074] The light processing device 200 of the second embodiment has a second heater upstream of the lamp house 2. The second heater is disposed upstream of the lamp house 2. The second heater heats the belt 1 located upstream of the lamp house 2. The second heater of this embodiment is a heater 41 and an infrared radiation heater 42 built into the first pulley 11. The heater 41 built into the first pulley 11 located upstream of the lamp house 2 heats the surface of the first pulley 11. This heats the belt 1 in contact with the first pulley 11. The infrared radiation heater 42 is disposed along the surface of the first pulley 11, sandwiching the belt 1 therebetween. The infrared radiation heater 42 radiates infrared rays toward the belt 1 to heat it. The infrared radiation heater 42 is particularly preferable as a heater for the belt 1 when the belt 1 is made of a material with high thermal emissivity, such as a resin.

[0075] The operation of the heaters (41, 42) will be described with reference to FIG. 7. FIG. 7 is an enlarged view of the area from the first pulley 11 to the front portion of the lamp house 2 in FIG. 6. However, FIG. 7 shows a state in which the heaters (41, 42) are not operating. When the light source 3 is turned on with the heaters (41, 42) not operating, the belt 1 may develop a wavy deflection D2 in which bulges in the +Z direction are periodically formed in the Y direction, as shown in FIG. 7. In FIG. 7, the dashed-dotted line 25 tangent to the guide roller 13 indicates the position of the belt 1 when there is no deflection D2.

[0076] Like deflection D1, this deflection D2 is presumably caused by a difference in the amount of thermal expansion within belt 1. Upstream of lamp house 2, the temperature of belt 1 is about room temperature, and belt 1 is in a contracted state. On the other hand, directly below lamp house 2, infrared rays from light source 3 heat up belt 1 near light source 3, causing it to expand.

[0077] When a difference in thermal expansion occurs inside the belt 1 moving at a constant speed, a wave-like deflection D2 appears in the belt 1. Note that while Figure 7 only shows the deflection D2 that appears in the YZ plane of the belt 1, the belt 1 also deflects in the width direction (X direction).

[0078] Therefore, the belt 1 is preliminarily heated before it enters the lamp house 2. This reduces the temperature rise of the belt 1 directly below the lamp house 2. As a result, the difference in thermal expansion between the belt 1 located upstream of the lamp house 2 and the belt 1 located directly below the lamp house 2 is reduced. As a result, the wavy deflection D2 is reduced, and the position of the belt 1 approaches the dashed-dotted line 25 or overlaps with the dashed-dotted line 25. This allows the distance between the light source 3 and the material 4 to be maintained, enabling the desired modification process to be performed uniformly.

[0079] 6 and 7, the optical processing device 200 is provided with a temperature sensor 45 that measures the temperature of the surface of the first pulley 11. Thus, by measuring the temperature of the surface of the first pulley 11, the temperature of the belt 1 immediately after it comes into contact with the first pulley 11 can be estimated. If the belt 1 is made of a material with low emissivity, such as metal, it is difficult to measure the amount of radiant heat of the belt 1. In this case, if the surface of the first pulley 11 is made of a material with relatively high emissivity, it is advisable to measure the amount of radiant heat of the first pulley 11 instead of the amount of radiant heat of the belt 1.

[0080] [Exhaust chamber] 6, the light processing device 200 includes an exhaust chamber 30 upstream of the lamp house 2 and an exhaust chamber 31 downstream of the lamp house 2. The exhaust chambers (30, 31) each have an exhaust port (32, 33) for discharging gas from the exhaust chambers (30, 31). Providing the exhaust chambers (30, 31) makes it easier to adjust the oxygen and humidity that flow into the lamp house 2 through the gap between the lamp house 2 and the belt 1. That is, the amount of exhaust air from the exhaust port (31, 32) may be controlled to adjust the oxygen concentration inside the lamp house 2.

[0081] Third Embodiment A third embodiment of the light treatment device will be described with reference to FIG. 8. In the light treatment device 300 of the third embodiment, the conveying body is not an endless belt but a plate 51 with ends. The plate 51 is long in the Y direction. Therefore, when a part of the plate 51 moves outside the lamp house 2 and is naturally cooled, the rest of the plate 51 is heated inside the lamp house 2. Therefore, a temperature difference can occur in the plate 51 in the Y direction. Furthermore, because the plate 51 is thin, a difference in thermal expansion due to a temperature difference in the Y direction can cause bending in the plate 51 in the Z direction.

[0082] Therefore, in order to reduce the deflection, it is effective to raise the temperature of the plate 51 by blowing the heating gas 23 from the heating gas supply unit 22 arranged downstream of the lamp house 2. Furthermore, as described in the second embodiment, it is also effective to preliminarily heat the plate 51 with the infrared radiation heater 42, which is the second heater arranged upstream of the lamp house 2.

[0083] The present invention is not limited to the above-described embodiments and their modifications, and the above-described embodiments and modifications may be combined as appropriate, or further modified.

[0084] Although the above-described optical processing device (100, 200, 300) has a single lamp house 2, a plurality of lamp houses 2 may be arranged in the transport direction (Y direction).

[0085] Although the above-described light treatment device (100, 200, 300) is shown as emitting ultraviolet light L1 in the same direction as the direction of gravity (-Z direction), the direction of emission of ultraviolet light L1 may be different from the direction of gravity. For example, ultraviolet light may be emitted horizontally to a transport body transported in the direction of gravity. [Explanation of symbols]

[0086] 1: Belt 2: Lamp House 3:Light source 4, 4a, 4b: Material to be treated 5: Exhaust space former 8: Gas supply port 9: Gas supply source 11: First pulley 12: Second pulley 13: Guide roller 14: Dancer Lola 18,45:Temperature sensor 19: Control section 21,41:Heater 22: Heating gas supply section 23: Heating gas 24, 32, 33: Exhaust port 30, 31: Exhaust chamber 42: Infrared radiation heater 43: Small Lola 51: Board 100, 200, 300: Optical processing equipment D1, D2: Deflection L1: Ultraviolet light

Claims

1. At least one light source that irradiates ultraviolet light in a wavelength band of 205 nm or less; a lamp house that covers the at least one light source and has an opening in a direction in which the ultraviolet light is emitted; a conveying body that conveys the material to be treated in one direction so as to cross a position facing the opening while leaving a gap between the conveying body and the lamp house; a heater disposed downstream of the lamp house and configured to heat the conveying body; a sensor for measuring the temperature of the conveyed body before or after the temperature is increased by the heater; a control unit that controls the transport of the workpiece while irradiating the workpiece with the ultraviolet light, The control unit controls the heater based on the results obtained from the sensor to heat the transport body so as to suppress a temperature drop of the transport body heated by the at least one light source.

2. 2. The light processing device according to claim 1, wherein the transport body is an endless belt stretched between a first pulley arranged upstream of the lamp house and a second pulley arranged downstream of the lamp house.

3. 3. The optical processing apparatus according to claim 1, wherein the heater radiates infrared rays toward the conveying body.

4. 3. The optical processing apparatus according to claim 1, wherein the heater injects a heated fluid toward the conveying body.

5. The optical processing device according to claim 2 , wherein the heater indirectly increases the temperature of the endless belt by increasing the temperature of the surface of the second pulley.

6. 3. The light processing device according to claim 1, further comprising a second heater disposed upstream of the lamp house for heating the conveying body.

7. 3. The light processing device according to claim 1, further comprising an exhaust chamber at least either upstream of said lamp house or downstream of said lamp house.

8. 6. The optical processing device according to claim 2, wherein the endless belt is mainly made of stainless steel.

9. 6. The optical processing device according to claim 2, wherein the endless belt has through holes that penetrate the endless belt in a thickness direction.

10. 6. The optical processing device according to claim 2, further comprising a guide roller disposed opposite the opening, and the endless belt is sandwiched between the opening and the guide roller.

11. 3. The optical processing device according to claim 1, further comprising a sensor for measuring the temperature of the transport body before or after the temperature is increased by the heater, or the amount of heat radiated by the heater.

12. While conveying a material having a resin on its surface in one direction by a conveyor, the material is irradiated with ultraviolet light in a wavelength band of 205 nm or less emitted from a light source in a lamp house in which oxygen is present; the material to be treated carried out from the lamp house is heated by the light source so as to suppress a decrease in the temperature of the material to be treated carried out from the lamp house; An optical processing method, characterized in that the temperature of the transport body is increased based on the results of measuring the temperature of the transport body before or after the temperature of the transport body is increased.

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