JP2006116508A - Light irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light irradiation device which is made smaller than a conventional device and is excellent in workability. <P>SOLUTION: The light irradiation device having a light source carrying out outgoing irradiation of light with which a photo-curable composition included in a coating, an adhesive or the like is irradiated and a casing storing the light source comprises the light source 110 consisting of a semiconductor light-emitting device, and the casing 101 providing means 102 for generating an air current blown to the photo-curable composition and having an opening part 111 for discharging emission of the semiconductor light-emitting device together with the air current. Further, an inert gas is supplied as the air current to accelerate curing of the photo-curable composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light irradiating device, and more particularly to a light irradiating device having a light emitting diode for irradiating light for curing a photocurable resin such as a paint or an adhesive.

  Some currently used paints and adhesives cure when irradiated with high energy light such as ultraviolet light in the wavelength range of 300 nm to 400 nm and visible light in the wavelength range of 400 nm to 500 nm. Some of them contain a photocurable material. As an apparatus for curing such paints, adhesives and the like by irradiation with high-energy light, an apparatus is known in which light from a light source such as a mercury lamp is guided by an optical fiber to be irradiated and cured.

  In particular, the ultraviolet irradiation device disclosed in Japanese Patent Application Laid-Open No. Sho 62-129802 has an optical fiber that guides light from the ultraviolet generation device, and the front end of the optical fiber has an ultraviolet ray derivation unit that emits ultraviolet light, And a hot-radiation part that emits hot air. The curing rate of the ultraviolet curable material can be improved by the hot air emitted from the heat ray radiating part.

Japanese Patent Laid-Open No. 62-129802.

  However, the conventional ultraviolet irradiation device has a problem that the device itself is enlarged. That is, the ultraviolet ray generator is composed of a mercury lamp, a reflecting mirror that is provided opposite to the mercury lamp and opens toward the light introducing portion of the optical fiber, and a filter that is disposed at a condensing position of the reflecting mirror. It is configured. In addition, a fan device is arranged at the rear of the ultraviolet ray generator, and the airflow that has become hot air by cooling the ultraviolet ray generator is from a main body of the ultraviolet ray irradiator to the ultraviolet ray irradiator by a hot air guide rod provided in the vicinity of the optical fiber. Be guided. As described above, the conventional ultraviolet irradiation apparatus not only increases the size of the apparatus itself, but also has a problem that the power consumption in the mercury lamp is large and it is difficult to finely adjust the irradiation intensity using a filter. In addition, it takes a certain amount of time to stably irradiate ultraviolet rays having a predetermined intensity, thereby reducing workability.

  Therefore, an object of the present invention is to provide a light irradiation apparatus that is smaller than the conventional one and has excellent workability.

  In order to achieve the above object, a light irradiation apparatus according to the present invention is a light irradiation apparatus having a light source that emits light irradiated to a photocurable composition, and a housing that houses the light source, The light source is composed of a semiconductor light emitting element, and the housing includes means for generating an air current to be sprayed on the photocurable composition, and has an opening for emitting light emitted from the semiconductor light emitting element together with the air current. Features. Thereby, it can be set as the light irradiation apparatus reduced in size rather than before and excellent in workability.

  Moreover, it is preferable that an inert gas is supplied to the said airflow. Thereby, the hardening rate of a photocurable composition can be improved and it can be set as the light irradiation apparatus excellent in workability | operativity.

  The opening of the housing is preferably tapered. Thereby, the light from the light source is condensed at the opening of the housing, and the wind from the means for generating the airflow is converged. Therefore, light and airflow can be reliably irradiated to the photocurable composition, and workability in the step of curing the photocurable composition can be improved.

  The inner wall surface of the housing is preferably a light reflecting surface. Thereby, the light from a light source can be efficiently guide | induced to an opening part.

  Moreover, it is preferable that the means for generating the air flow is disposed on the side opposite to the light emitting direction of the semiconductor light emitting element. Thereby, while improving the heat dissipation of a semiconductor light-emitting device, the airflow heated by the semiconductor light-emitting device can be discharge | released to a photocurable composition. Therefore, hardening of a photocurable composition is accelerated | stimulated and it can be set as the light irradiation apparatus excellent in workability | operativity.

  The means for generating the airflow is preferably an electric fan. Thereby, an airflow can be generated efficiently.

  The present invention uses a light emitting diode or a semiconductor laser element as a light source. Further, the housing has an opening for releasing the airflow generated by the airflow generating means together with the light from the light source. Therefore, the present invention can be a light irradiation apparatus that is smaller than the conventional ultraviolet irradiation apparatus and has excellent workability.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the form shown below illustrates the light irradiation apparatus for embodying the technical idea of the present invention, and the present invention does not limit the light irradiation apparatus below. Further, the present specification by no means specifies the members shown in the claims as the members of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention only to a specific description unless otherwise specified. It is just an example. Note that the size and positional relationship of the members shown in the drawings may be exaggerated for the sake of clarity.

  In order to solve the above-described problems, a light irradiation apparatus according to the present invention includes a light source including a semiconductor light emitting element that emits light irradiated onto a photocurable composition. By using a semiconductor light emitting device such as a light emitting diode or a semiconductor laser device as a light source, the device itself can be made smaller than conventional ultraviolet irradiation devices, reducing power consumption and finely adjusting the light irradiation intensity. Becomes easy. In addition, by using the semiconductor light emitting element as a light source, it is possible to shorten the time required for stably irradiating light having a certain intensity and to improve workability.

  Furthermore, the light irradiation apparatus concerning this invention has the airflow production | generation means which produces | generates the airflow sprayed on the said photocurable composition, It is characterized by the above-mentioned. Thereby, the cure rate of a photocurable composition can be improved and workability | operativity can be improved. For example, by removing moisture generated at the stage of the curing reaction of the photocurable resin from the periphery of the photocurable resin, the curing rate of the photocurable resin can be improved.

  More specifically, as shown in FIG. 1, the light irradiation device according to the present invention includes a light source composed of a light emitting diode or a semiconductor laser element, and an airflow generating means for generating an airflow sprayed on the photocurable composition. And a suction port for introducing outside air into the housing and a discharge port for discharging an air current blown to the photocurable composition. Here, the airflow generation means in the present embodiment refers to a device that can cause a gas flow inside the housing. For example, compressed air from an electric fan or a compressor can be used.

  Moreover, the said housing | casing has a channel | path which guide | induces light emission of a semiconductor light-emitting device to a photocurable composition with the airflow from an airflow production | generation means. The inner wall surface of the passage formed in the housing is preferably a light reflecting surface. Thereby, the light emitted from the light source can be efficiently guided to the discharge port. Furthermore, it is preferable that the passage is gradually tapered toward the photocurable composition. Thereby, the light emitted from the light source can be efficiently condensed and guided to the emission port. Further, the airflow from the airflow generating means can be converged and released.

  The inert gas that can be supplied to the airflow generated by the airflow generating means is an inert gas that does not adversely affect the curing reaction of the photocurable composition, such as nitrogen gas or argon gas. Such an inert gas is supplied from a suction port provided in the casing by a device such as a compressor. By supplying such a gas, the oxygen concentration around the photocurable composition can be reduced. For example, the surface of the photocurable resin applied to the adhesive surface may have a functional group that reacts with oxygen to generate moisture. By spraying an inert gas on the surface of such a photocurable resin, the oxygen concentration can be reduced, stickiness of the surface of the photocurable resin can be prevented, and the curing rate can be increased. The position where such an inert gas is supplied can be between the airflow generating means and the light source composed of the semiconductor light emitting element. Thereby, an inert gas can be efficiently discharged | emitted toward the photocurable composition.

  When it is desired to accelerate the curing of the photocurable composition by applying not only the light energy from the light source but also the heat energy to the photocurable composition, an air flow generating means such as an electric fan is operated. Then, outside air is introduced into the passage in the casing through the suction port provided at the rear end of the casing. The outside air introduced in this way is heated in the vicinity where the semiconductor light emitting element is disposed to become hot air, and is discharged from the discharge port toward the photocurable composition. Hereinafter, each structure of this form is explained in full detail.

(Semiconductor light emitting device)
The semiconductor light emitting element in this embodiment is a light emitting diode or a semiconductor laser that emits light capable of curing the photocurable composition. Examples thereof include those capable of emitting ultraviolet rays in the wavelength range of 300 nm to 400 nm, visible light in the wavelength range of 400 nm to 500 nm, and the like. Examples of the semiconductor light emitting element constituting such a light emitting diode include those using various semiconductors such as ZnSe and GaN. In particular, the above-mentioned short wavelength of the nitride semiconductor capable of emitting light _{(In X Al Y Ga 1-} X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is preferably exemplified. Examples of the semiconductor structure include a homostructure having a MIS junction, a PIN junction, and a pn junction, a heterostructure, and a double heterostructure. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal. In addition, a single quantum well structure or a multiple quantum well structure in which the semiconductor active layer is formed in a thin film in which a quantum effect is generated can be used.

  When a nitride semiconductor is used, a material such as sapphire, spinel, SiC, Si, ZnO or the like is preferably used for the semiconductor substrate. In order to form a nitride semiconductor with good crystallinity with high productivity, it is preferable to use a sapphire substrate. A nitride semiconductor can be formed on the sapphire substrate by MOCVD or the like. A buffer layer of GaN, AlN, GaAlN or the like is formed on the sapphire substrate, and a nitride semiconductor having a pn junction is formed thereon.

  As an example of a light emitting device having a pn junction using a nitride semiconductor, a first contact layer formed of n-type gallium nitride, a first clad layer formed of n-type aluminum nitride / gallium on a buffer layer, Examples include a double hetero structure in which an active layer formed of indium / gallium nitride, a second cladding layer formed of p-type aluminum nitride / gallium, and a second contact layer formed of p-type gallium nitride are sequentially stacked. .

  Nitride semiconductors exhibit n-type conductivity without being doped with impurities. When forming a desired n-type nitride semiconductor, for example, to improve luminous efficiency, it is preferable to appropriately introduce Si, Ge, Se, Te, C, etc. as an n-type dopant. On the other hand, when forming a p-type nitride semiconductor, the p-type dopants such as Zn, Mg, Be, Ca, Sr, and Ba are doped. Since nitride semiconductors are not easily converted to p-type by simply doping with a p-type dopant, it is preferable to reduce resistance by heating in a furnace or plasma irradiation after introducing the p-type dopant.

  The p-type semiconductor layer is provided with a diffusion electrode for spreading the current input to the light emitting element over the entire surface of the p-type semiconductor layer. Furthermore, a p-side pedestal electrode and an n-side pedestal electrode connected to a conductive member such as a bump or a conductive wire are provided on the diffusion electrode and the n-type semiconductor layer, respectively. Here, examples of the material of the bump include Au, Au—Sn eutectic, and lead-free solder. Moreover, as a material of an electroconductive wire, the fine wire which consists of Al, Au, Cu, or the alloy containing them is mentioned, for example.

  The diffusion electrode, the p-side pedestal electrode, and the n-side pedestal electrode are formed by an evaporation method or a sputtering method after exposing the n-type semiconductor by a method such as etching. Further, the shape of the diffusion electrode or the p-side pedestal electrode may be various shapes so that the current spreads uniformly over the entire surface of the light emitting element.

  In this embodiment, the material for the p-side and n-side pedestal electrodes preferably contains at least one of the materials contained in the bumps and conductive wires. That is, when the bump or the conductive wire is made of Au, the material of the p-side and n-side pedestal electrode, particularly the uppermost layer that becomes the bonding surface with the bump or the conductive wire is Au or an alloy containing Au. And For example, the p-side and n-side pedestal electrodes are made of W / Pt / Au or Rh / Pt / Au, and the thickness of each metal is several hundred to several thousand. In this specification, the symbol “A / B” indicates that the metal A and the metal B are sequentially laminated by a method such as sputtering or vapor deposition.

  The diffusion electrode formed on the entire surface of the p-type semiconductor layer is preferably made of a material that reflects light emitted from the light-emitting element toward the light-transmitting substrate of the light-emitting element. For example, Ag, Al, Rh, Rh / Ir can be mentioned. Furthermore, in combination with these materials, or alone, an oxide conductive film such as ITO (complex oxide of indium (In) and tin (Sn)), ZnO, Ni / Au, etc. on the entire surface of the p-type semiconductor. The metal thin film can be formed as a translucent electrode.

  A semiconductor light emitting device according to another embodiment is composed only of a nitride semiconductor layer, and counter electrodes are formed on the upper surface and the lower surface of the semiconductor layer. The semiconductor light emitting element having such a counter electrode is fixed via a conductive adhesive so that one electrode faces the support substrate according to this embodiment. Therefore, one electrode of the light emitting element is electrically connected to the conductor wiring of the support substrate, and the other electrode is connected to the conductor wiring having a polarity different from that of the conductor wiring through the conductive wire. Examples of the material for the conductive adhesive include silver paste, and eutectic materials such as Au—Sn and Ag—Sn.

  Hereinafter, a method for forming a semiconductor light emitting device having such a counter electrode structure will be described. First, after laminating an n-type nitride semiconductor layer and a p-type nitride semiconductor layer in the same manner as the semiconductor element described above, an insulating film is formed on the p-type nitride semiconductor layer other than the p-electrode serving as the first electrode and the p-electrode. Form. On the other hand, a support substrate to be bonded to the semiconductor layer is prepared. Specific materials for the support substrate include Cu—W, Cu—Mo, AlN, Si, SiC, and the like. A structure having an adhesion layer, a barrier layer, and a eutectic layer on the bonding surface is preferable. For example, a metal film such as Ti—Pt—Au or Ti—Pt—AuSn is formed. Such a metal film is alloyed by eutectic and becomes a conductive layer in a later step.

  Next, the surface of the support substrate on which the metal film is formed and the surface of the nitride semiconductor layer face each other, heat is applied while pressing and alloyed, and then an excimer laser is irradiated from the different substrate side or by grinding. Remove the dissimilar substrate. Thereafter, outer peripheral etching is performed by RIE or the like in order to form a nitride semiconductor element, thereby obtaining a nitride semiconductor element in a state where the outer peripheral nitride semiconductor layer is removed. In order to improve the light extraction effect, the exposed surface of the nitride semiconductor may be roughened (dimple processing) by RIE or the like. The cross-sectional shape of the unevenness includes a mesa shape and an inverted mesa shape, and the planar shape includes an island shape, a lattice shape, a rectangular shape, a circular shape, a polygonal shape, and the like. Next, an n electrode as a second electrode is formed on the exposed surface of the nitride semiconductor layer. Examples of the electrode material include Ti / Al / Ni / Au and W / Al / WPt / Au.

  The semiconductor light emitting element in this embodiment is preferably placed on a support member called a package. Thereby, the semiconductor element can be protected from dust and the like in the housing. Furthermore, it is preferable that the package has a recess for placing the semiconductor element. The electrode exposed in the recess and the semiconductor element disposed on the bottom of the recess are electrically connected by a conductive wire such as a gold wire or a conductive paste such as an Ag-containing epoxy resin.

(package)
The package in this embodiment has a conductor wiring or a lead electrode that holds the semiconductor light emitting element and is electrically connected to the semiconductor light emitting element, and protects the semiconductor light emitting element from the external environment.

  In particular, the package in this embodiment preferably has a semiconductor light emitting element arranged on the bottom surface of a recess formed in the package. Such a package is preferably formed using various resins such as epoxy resin, silicone resin, imide resin, acrylic resin, PBT (polybutylene terephthalate), liquid crystal polymer, and aromatic nylon.

  In this embodiment, a can package mainly made of a metal material is preferably used as a package for mounting a semiconductor element that emits high-energy light. The can package includes a stem on which the semiconductor light emitting element is placed and the lead electrode is fixed, and a cap having a glass transparent window portion. The stem and the cap are joined, and the semiconductor light emitting device is hermetically sealed.

  The package can be a ceramic package obtained by laminating and firing ceramic green sheets. Since the ceramic package is superior in heat resistance and light resistance as compared with a package made of a resin material, it can be a light source with high output and high reliability without causing coloring deterioration. Moreover, it is preferable that the ceramic package which has a recessed part makes the inner wall surface of the recessed part the reflective surface which consists of a metal material with a high light reflectance. As a result, light from the semiconductor light emitting element is not absorbed by the ceramics, so that a light emitting diode having excellent light extraction efficiency can be obtained. Moreover, it is preferable that the recessed part of the ceramic package is covered with translucent members, such as glass. Thereby, a semiconductor element can be protected from dust etc. in a housing.

(Mounting board)
The mounting substrate in this embodiment is a member on which a semiconductor light emitting element is mounted and arranged inside the housing. Alternatively, when the semiconductor light emitting device is mounted on the above-described package, the package (conductor wiring disposed in the package) can be electrically and mechanically connected. Further, the mounting substrate is provided with conductor wiring for supplying power to the semiconductor light emitting element. Such a mounting substrate can be suitably configured by a glass epoxy substrate on which a conductive pattern made of copper foil or the like is formed, a metal body bonded with an insulating resin, or the like. Alternatively, a conductive pattern can be applied to a metal material made of aluminum or copper via an insulating material. Moreover, in order to improve heat dissipation, the mounting substrate is preferably disposed in the housing via a heat dissipation sheet. Moreover, it is preferable that the mounting substrate has an opening through which airflow generated by the airflow generating means disposed behind the mounting substrate can pass in the direction of irradiating light from the semiconductor light emitting element. Furthermore, it is preferable that a heat radiating member such as a heat radiating fin is provided on the side receiving the air flow from the air flow generating means.

(Casing)
The casing in this embodiment is one that houses at least the semiconductor light emitting element and the airflow generation means and can mechanically hold them. Furthermore, it has an inlet for introducing outside air and an outlet for releasing the introduced outside air into the photocurable composition. A passage is formed in the housing with the inlet and the outlet as openings. By this passage, the light emitted from the semiconductor light emitting element together with the outside air introduced from the suction port by the airflow generation means is guided toward the discharge port. A mounting substrate on which the semiconductor light emitting element is mounted is disposed inside the passage, and an airflow generating means is disposed between the mounting substrate and the suction port. Thereby, the external air introduced from the suction port can be efficiently blown onto the mounting board, and the heat dissipation of the semiconductor light emitting element mounted on the mounting board can be improved. Moreover, the airflow heated with the heat | fever of the semiconductor light-emitting element can be sprayed with respect to a photocurable composition.

  As the material for the housing in this embodiment, various materials such as resin and metal having high light resistance and heat resistance are preferably exemplified. For example, in consideration of improving heat dissipation from semiconductor light emitting elements, reducing the weight of light irradiation devices, and reflecting and guiding light from semiconductor light emitting elements, metals such as nickel, iron, copper, and aluminum, stainless steel, etc. These alloys are appropriately selected. In particular, since the inner wall surface of the passage formed in the housing is a light reflecting surface, it is preferable that a metal material having a high light reflectance such as silver (Ag) or aluminum (Al) is disposed. Further, the size and shape of the housing can be variously selected according to the size and shape of the electric fan or the light emitting diode.

  It is preferable that the shape of the discharge port provided at the front end portion of the housing in this embodiment is tapered. Thereby, the light from the light source is condensed, and the airflow from the airflow generating means is converged and emitted. Therefore, the photocurable composition arranged at a predetermined position can be efficiently cured.

  Examples according to the present invention will be described in detail below. Needless to say, the present invention is not limited to the following examples.

  FIG. 1 is a sectional view of a light irradiation apparatus according to an embodiment of the present invention. The light irradiation apparatus according to the present embodiment includes a cylindrical housing in which an irradiation source made of a light emitting diode is disposed, and an electric fan for generating an airflow inside the housing.

  The inner wall surface of the cylindrical casing is silver-plated to reflect light emitted from the light emitting diode in the direction of the emission port.

  The electric fan includes a propeller 102 and an electric motor 103 which is a driving means for driving the propeller.

  A switch 107 is disposed on the outer wall surface of the housing 101. Connected to the switch 107 are a wiring 105 connected to a power supply external to the light irradiation apparatus 100, a wiring 106 connected to the electric motor 103, and a wiring 108 connected to a conductor wiring provided on the mounting substrate 109. By switching ON / OFF of such a switch, a light emitting diode and / or an electric fan can be driven.

  The irradiation source made up of light emitting diodes is one in which a plurality of light emitting diodes having a main light emission peak wavelength of 350 nm to 500 nm are mounted on a mounting substrate provided with conductor wiring. Further, the mounting board is formed with a through hole through which airflow from the electric fan passes. Thereby, the airflow from the electric fan arranged behind the mounting board passes through the through hole, and the airflow can be guided toward the discharge port on the front surface of the light irradiation device. Moreover, the heat dissipation of the light emitting diode arranged on the mounting substrate can be improved. Moreover, the airflow heated with the light emitting diode can be sprayed on photocurable resin, and the curing reaction of photocurable resin can be accelerated.

  The present invention can be used as a light irradiation device for curing a photocurable material contained in, for example, a paint or an adhesive.

FIG. 1 is a schematic cross-sectional view of a light irradiation apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Light irradiation apparatus 101 ... Case 102 ... Airflow generation means 103 ... Drive apparatus 104 of airflow generation means ... Inlet 105, 106, 108 ... Wiring 107 ... Switch 109: Mounting substrate 110 ... Semiconductor element 111 ... Opening

Claims (6)

A light irradiation device having a light source that emits light irradiated to the photocurable composition, and a housing that houses the light source,
The light source is composed of a semiconductor light emitting element, and the housing includes means for generating an air current to be sprayed on the photocurable composition, and has an opening for emitting light emitted from the semiconductor light emitting element together with the air current. A light irradiation device characterized. The light irradiation apparatus according to claim 1, wherein an inert gas is supplied to the airflow. The light irradiation apparatus according to claim 1, wherein the opening of the housing is tapered. The light irradiation apparatus according to claim 1, wherein an inner wall surface of the housing is a light reflecting surface. 5. The light irradiation apparatus according to claim 1, wherein the means for generating the airflow is disposed on a side opposite to a light emitting direction of the semiconductor light emitting element. The light irradiation device according to claim 1, wherein the means for generating the airflow is an electric fan.

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