Ultraviolet irradiation device

Abstract

To provide an ultraviolet light irradiation device that can increase the number of LED chips that can be mounted and obtain a large light output. [Solution] In an ultraviolet light irradiation device 1 using multiple LED chips 2 that emit ultraviolet light, each LED chip 2 is directly mounted on a mounting substrate 3. Compared to conventional devices in which each LED chip is packaged and mounted on the substrate, the number of mountable LED chips is increased, and a large light output can be obtained.

Description

【Technical Field】 【0001】 The present invention relates to an ultraviolet light irradiation device using a plurality of LED chips. 【Background Art】 【0002】 As an ultraviolet light irradiation device using a plurality of ultraviolet LED chips, for example, one provided in the insect killing device described in Patent Document 1 is known. In the ultraviolet light irradiation device described in Patent Document 1, each LED chip is packaged, and a plurality of LED packages are mounted on a flat panel. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2001-86916 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 However, when packaging each LED chip as in Patent Document 1, there is a problem that the number of LED chips that can be mounted on the ultraviolet light irradiation device is limited and the light output cannot be increased. 【0005】 The present invention has been made in view of the above circumstances, and an object thereof is to provide an ultraviolet light irradiation device capable of increasing the number of LED chips that can be mounted and obtaining a large light output. 【Means for Solving the Problems】 【0006】 In the present invention, a plurality of LED chips that emit ultraviolet light, and a mounting substrate on which each of the LED chips is directly mounted, are provided in an ultraviolet light irradiation device. 【0007】 In the above-described ultraviolet light irradiation device, the peak wavelength of each LED chip is preferably 360 nm or more and 375 nm or less. 【0008】 In the above-described ultraviolet light irradiation device, it is preferable that the mounting substrate has at least two constant current diodes connected in series with the LED chips. 【0009】 In the above-described ultraviolet light irradiation device, the mounting substrate is preferably an aluminum-based substrate. 【0010】 In the above ultraviolet light irradiation device, when viewed from a direction perpendicular to the mounting surface of the LED chip on the mounting substrate, the entire device has a length of 1 cm 2 A light output of 72mW or more per unit is preferable. 【0011】 In the above ultraviolet light irradiation device, when viewed from a direction perpendicular to the mounting surface of the LED chip on the mounting substrate, the entire device has a length of 1 cm 2 A light output of 432mW or more per unit is preferable. [Effects of the Invention] 【0012】 According to the ultraviolet light irradiation device of the present invention, the number of LED chips that can be mounted can be increased, and a large light output can be obtained. [Brief explanation of the drawing] 【0013】 [Figure 1] This is a front view of an ultraviolet light irradiation device showing one embodiment of the present invention. [Figure 2] This is a circuit diagram of an ultraviolet light irradiation device. [Figure 3] This is a partial cross-sectional view of an ultraviolet light irradiation device. [Figure 4] This is a front view of a modified ultraviolet light irradiation device. [Modes for carrying out the invention] 【0014】 Figures 1 to 3 show one embodiment of the present invention, with Figure 1 being a front view of an ultraviolet light irradiation device. As shown in Figure 1, the ultraviolet light irradiation device 1 includes a plurality of LED chips 2 that emit ultraviolet light and a mounting substrate 3 on which each LED chip 2 is directly mounted. The mounting substrate 3 is formed in a square shape, and each LED chip 2 is mounted in a predetermined direction. In this embodiment, 10 LED chips 2 arranged horizontally form a series connection section 5 together with a constant current diode 4, and two series connection sections 5 are arranged vertically with a gap between them near the vertical center of the mounting substrate 3. 【0015】 Each LED chip 2 can be of any size, for example, 300 μm × 300 μm or 350 μm × 350 μm in plan view, and is mounted on the mounting substrate 3 at predetermined intervals. By directly mounting each LED chip 2, a highly integrated structure of each LED chip 2 is realized. In this embodiment, the mounting substrate 3 is 5 cm × 5 cm in plan view. The mounting interval of each LED chip 2 is arbitrary, but for example, it can be 20 μm or more and 1000 μm or less. From the viewpoint of high integration, the mounting interval of each LED chip 2 is preferably 200 μm or less, and more preferably 100 μm or less. 【0016】 Figure 2 is a circuit diagram of the ultraviolet light irradiation device. As shown in Figure 2, each series connection section 5 is connected in parallel. Each LED chip 2 has, for example, an InGaN-based light-emitting layer and emits ultraviolet light. The voltage v1 applied to each series connection section 5 is arbitrary, but in this embodiment it is 45V. In this embodiment, the peak wavelength of each LED chip 2 is 365nm. The peak wavelength of each LED chip 2 is arbitrary, but can be set arbitrarily within the range of 360nm to 375nm. Also, in this embodiment, the light output of each LED chip 2 is 90mW. Since the ultraviolet light irradiation device 1 is equipped with 20 LED chips 2, the total light output of the device is 1800mW. That is, when viewed from a direction perpendicular to the mounting surface of each LED chip 2 on the mounting substrate 3, the total light output of the device is 1cm². 2The light output is 72 mW per unit area. In the present embodiment, since each series connection section 5 has each constant current diode 4, even if the performance such as Vf of each LED chip 2 varies, each LED chip 2 can be made to emit light stably. 【0017】 FIG. 3 is a partial cross-sectional view of the ultraviolet light irradiation device. As shown in FIG. 3, the mounting substrate 3 has an aluminum base 31, a resin layer 32 formed on the upper side of the aluminum base and made of resin, and a copper pattern 33 formed on the upper side of the resin layer 32. The aluminum base 31 is formed thicker than the resin layer 32 and the copper pattern 33. The resin layer 32 is made of, for example, polyimide resin, epoxy resin, liquid crystal polymer, etc., and insulates the conductive aluminum base 31 and the copper pattern 33. The copper pattern 33 is made of copper having a thin film of gold on the surface (upper surface), and is electrically connected to each LED chip 2 and the wire 6. In the present embodiment, each LED chip 2 is a face-up type and is electrically connected to the copper pattern 33 by the wire 6 respectively. The copper pattern 33 has a thin film of gold on the surface (upper surface). 【0018】 In the ultraviolet light irradiation device 1 configured as described above, since a plurality of LED chips 2 that emit ultraviolet light are directly mounted on the mounting substrate 3, the number of LED chips 2 that can be mounted can be increased, and a large light output can be obtained. In particular, when viewed from the direction perpendicular to the mounting surface of each LED chip 2 of the mounting substrate 3, as a whole device, it has a light output of 72 mW or more per 1 cm 2 By setting the light output to 72 mW or more per unit area, it far exceeds the light output of the conventionally known ultraviolet light irradiation device. Also, since the mounting substrate 3 is an aluminum base substrate, the heat dissipation is good, the heat generated by each LED chip 2 is accurately dissipated, and the decrease in luminous efficiency due to heat generation is suppressed. Incidentally, by using a copper base substrate for the mounting substrate 3, it is also possible to further improve the heat dissipation. 【0019】 In the above embodiment, a configuration with 20 LED chips 2 was shown, but the number of LED chips 2 can be arbitrarily changed. For example, as shown in Figure 5, the number of LED chips 2 mounted on the mounting substrate 103 can be 120. In the ultraviolet light irradiation device 101 of Figure 5, 12 series connection sections 5 are provided. In this case, the light output of the ultraviolet light irradiation device 101 is 10800mW, and when viewed from a direction perpendicular to the mounting surface of each LED chip 2 on the mounting substrate 103, the entire device has a power output of 1cm². 2 The light output is 432mW per unit. Thus, when viewed from a direction perpendicular to the mounting surface of each LED chip 2 on the mounting board 3, 1cm 2 It is even more preferable to have an optical output of 432mW or more per unit. 【0020】 Although embodiments of the present invention have been described above, the embodiments described above do not limit the invention as defined in the claims. Furthermore, it should be noted that not all combinations of features described in the embodiments are necessarily essential for solving the problem of the invention. [Explanation of symbols] 【0021】 1 Ultraviolet light irradiation device 2 LED chips 3. Implemented circuit board 4. Constant current diode 5. Series connection section 6 wires 101 Ultraviolet light irradiation device 103 Mounting board

Claims

[Claim 1] Multiple LED chips that emit ultraviolet light, An ultraviolet light irradiation device having a mounting substrate on which each of the aforementioned LED chips is directly mounted. [Claim 2] The ultraviolet light irradiation device according to claim 1, wherein the peak wavelength of each LED chip is 360 nm or more and 375 nm or less. [Claim 3] The ultraviolet light irradiation device according to claim 2, further comprising a constant current diode connected in series with at least two LED chips on the mounting substrate. [Claim 4] The ultraviolet light irradiation apparatus according to claim 3, wherein the mounting substrate is an aluminum-based substrate. [Claim 5] When viewed from a direction perpendicular to the mounting surface of the LED chip on the aforementioned mounting substrate, the entire device has a length of 1 cm. ２ The ultraviolet light irradiation device according to claim 4, wherein the light output is 72 mW or more per unit. [Claim 6] When viewed from a direction perpendicular to the mounting surface of the LED chip on the aforementioned mounting substrate, the entire device has a length of 1 cm. ２ The ultraviolet light irradiation device according to claim 4, wherein the light output is 432 mW or more per unit.

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