JP2010044872A - Illuminating device of security-increase explosion-proof structure - Google Patents

Abstract

An illumination device having a safety explosion-proof structure using a light emitting diode as a light source is provided.
In a lighting device 100, a substrate 1 having a plurality of lamp structures 10 provided on a surface thereof is provided at an appropriate position in a box-shaped casing 101 having an opening on one surface. A transparent window 103 using tempered glass or the like is provided in the opening. A synthetic rubber packing 104 is provided on the upper and lower surfaces of the edge of the transparent window 103, and the transparent window 103 is fixed to the housing 101 with the front frame 102. The lamp structure 10 includes a synthetic resin sealing part that wire-bonds an LED chip mounted on the substrate 1 and an electrode part provided on the substrate with a wire, and seals the LED chip, the wire, and the electrode part.
[Selection] Figure 1

Description

  The present invention relates to an explosion-proof illuminating device used in a hazardous area such as a factory or business office that handles flammable gas or flammable liquid, and more particularly, a lighting device having a safety explosion-proof structure using a light emitting diode (LED) as a light source. About.

  In recent years, lighting devices that use light-emitting diodes (LEDs) as light sources instead of incandescent lamps and fluorescent lamps have been commercialized from the viewpoint of energy saving and environmental considerations. There is a growing demand for such lighting devices to be installed not only in general homes and offices, but also in factories and offices that handle flammable gases and flammable liquids.

  Electrical equipment installed in such a hazardous area is required to have a structure with safety measures, and two explosion-proof structures, a flameproof structure and a safety explosion-proof structure, are used. The explosion-proof construction is resistant to internal explosions in explosive atmospheres that have infiltrated containers of electrical equipment without being damaged, and to external explosive atmospheres through all joints or structural openings of the containers. An explosion-proof structure for electrical equipment that can prevent ignition. In addition, the safety explosion-proof structure is an explosion-proof structure that is applied to electrical equipment that does not generate arcs or sparks during normal use, which may cause abnormal arcs and sparks and excessive temperature rise. On the other hand, it refers to an explosion-proof structure for electrical equipment that is provided with measures to increase safety.

  With the explosion-proof construction, there is no explosion-proof requirement for the contents contained in the electrical equipment if the electrical equipment container is made the explosion-proof construction. Since it is required, the shape of the lighting device increases, the weight increases, and the cost also increases. In contrast, the safety-explosion-proof structure has less stringent requirements on the strength of the container than the explosion-proof structure, so the container can be made smaller and lighter, resulting in smaller and lighter electrical equipment and lower costs. Can be realized.

On the other hand, lighting devices using light-emitting diodes are those in which surface-mounted light-emitting diodes are soldered on the circuit board, or light-emitting diode lamp lead frames are inserted and soldered on the circuit board. (See Patent Document 1).
JP 2003-133594 A

  However, in the lighting device disclosed in Patent Document 1, in general, when an electronic component (for example, an LED) is mounted on a substrate, the terminals of the electronic component are connected to the substrate by soldering. , Can not meet the requirements of safety explosion-proof structure. In addition, the electrical insulation distance (for example, the insulation space distance and creepage distance) on the substrate is determined by the outer shape of the LED or the like, and it is difficult to satisfy the requirements for the safety explosion-proof structure. In addition, in an explosion-proof lighting device using a light emitting diode, there has been a demand for adopting a safety-explosion-proof structure that can realize a reduction in size and weight and cost.

  This invention is made | formed in view of such a situation, and it aims at providing the illuminating device of the safety explosion-proof structure which uses a light emitting diode as a light source.

  An illumination device having a safety explosion-proof structure according to a first aspect of the present invention includes a substrate and an LED chip mounted on the substrate, wherein the electrode portion provided on the substrate and the LED chip are wire-bonded, A sealing portion made of a synthetic resin for sealing the LED chip and the electrode portion is provided.

  A lighting device having a safety explosion-proof structure according to a second aspect of the present invention is the lighting device according to the first aspect, further comprising a conductive portion connected to the electrode portion through a conductive pattern formed on the substrate, It is mechanically connected.

  In the first invention, the LED chip mounted on the substrate and the electrode portion provided on the substrate are wire-bonded, and the sealing portion made of synthetic resin for sealing the LED chip and the electrode portion is provided. As a result, the LED chip as the light emitting part can be prevented from directly touching the explosive atmosphere, and the sealed part in which the LED chip is sealed can be regarded as a lamp structure. Can meet the matter.

  In the second invention, a conductive part connected to the electrode part through a conductive pattern formed on the substrate is provided, and an electric wire is mechanically connected to the conductive part. The mechanical connection is, for example, a connection method such as screw tightening, rivet tightening, or crimping connection with a loose stop. As a result, it is possible to prevent contact failure due to heat generation or vibration at the connection portion between the conductive portion of the substrate on which the LED chip is provided and the electric wire for supplying power to the LED chip, and the safety explosion-proof structure of the conductive portion can be prevented. The requirements can be met.

  ADVANTAGE OF THE INVENTION According to this invention, the illuminating device of a safe explosion-proof structure using a light emitting diode as a light source is realizable.

  Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a schematic diagram showing an example of the structure of a lighting apparatus 100 having a safety explosion-proof structure according to the present invention. In the lighting device 100, a substrate 1 having a plurality of lamp structures 10 provided on a surface thereof is provided at an appropriate position in a box-shaped casing 101 having an opening on one surface. The substrate 1 is arranged so that the lamp structure 10 faces the opening. A transparent window 103 using a flame retardant material having a strength equal to or higher than that of tempered glass or tempered glass is provided in the opening. A synthetic rubber packing 104 is provided on the upper and lower surfaces of the edge of the transparent window 103, and the transparent window 103 is fixed to the housing 101 with the front frame 102.

  In addition, the structure of the above-described lighting device 100 is an example, and is not limited thereto, and the shape viewed from above the transparent window 103 may be a square, a rectangle, or a circle. In addition, in the example of FIG. 1, the configuration is such that one substrate 1 is provided. It is also possible to provide a plurality of openings in the housing 101 and provide the transparent window 103 in each opening.

  Note that the safety-explosion-proof lighting device must satisfy the following requirements. That is, to ensure an electrical insulation distance (creeping distance and insulation space distance) on the substrate and to satisfy the connection method of the conductive parts.

  FIG. 2 is a cross-sectional view showing an example of the lamp structure 10. In FIG. 2, reference numeral 1 denotes a substrate such as an aluminum plate. The substrate 1 may be an aluminum alloy. Further, the substrate 1 may be a substrate or may be anodized. At least the surface of the substrate 1 on which the LED chip (bare chip) 2 as the light emitting portion is mounted (the periphery of the LED chip 2 after mounting) is glossy and can reflect the light emitted by the LED chip 2.

  On the board | substrate 1, the thermoplastic resin film board | substrate 3 which has the opening part 9 for arrange | positioning LED chip 2 is mounted | worn with the hot press. The hot pressing can be performed at a relatively low temperature of about 200 ° C., for example. Further, the thermoplastic resin film substrate 3 can be mounted on the substrate 1 by hot pressing.

  The thermoplastic resin film substrate 3 is obtained by forming a copper foil 3b on the surface of an insulating film 3a. The copper foil 3b has a circuit pattern (conductive pattern) formed in advance before the thermoplastic resin film substrate 3 is mounted on the substrate 1 by hot pressing by deleting unnecessary portions. In addition, as the electrical insulation distance on the thermoplastic resin film substrate 3, for example, the creeping distance is 1.8 mm or more. Further, the creepage distance can be appropriately determined according to the power supply voltage for supplying power to the LED chips 2.

  The LED chip 2 is mounted on the substrate 1 so as to be disposed in the opening 9 of the thermoplastic resin film substrate 3. For mounting the LED chip 2, for example, a transparent paste can be used. A wire 5 is used for wire bonding between the electrode of the LED chip 2 and the electrode portion of the copper foil 3b. In addition, the gold plating is performed beforehand in the location (electrode part) of the copper foil 3b wire-bonded by the gold wire 5. FIG.

  A resist layer 4 is formed on the surface of the copper foil 3b except for the portion where the gold plating of the copper foil 3b is applied. A silicon material 6 such as translucent silicon is provided around the opening 9 of the thermoplastic resin film substrate 3, and a region surrounded by the silicon material 6 is filled with a silicon potting material 8 such as transparent silicon. It is. The silicon potting material 8 has a function as a sealing portion that seals a portion (electrode portion) where the gold plating of the LED chip 2, the gold wire 5 and the copper foil 3b as the light emitting portion is performed.

  A phosphor sheet 7 is bonded to the upper part of the silicon material 6. With the phosphor sheet 7, for example, a function as a white light emitting diode that generates white light can be realized.

  With the configuration as described above, the LED chip 2 as the light emitting unit can be prevented from directly touching the explosive atmosphere, and the LED chip 2 on the substrate 1 is hermetically sealed (the LED chip 2 and the gold wire 5). Further, the gold-plated portions of the copper foil 3b and the silicon potting material 8) for sealing them can be regarded as the lamp structure 10, and the requirements for the safety explosion-proof structure of the light emitting part can be satisfied.

  The lamp structure including the LED chip as the light emitting unit is not limited to the above-described example, and may have another configuration. Next, another lamp structure will be described. FIG. 3 is a cross-sectional view showing an example of the lamp structure 20. As shown in FIG. 3, the lamp structure 20 includes an insulating layer 21 formed on a substrate 1 such as an aluminum substrate or a copper substrate, and a circuit pattern (conductive pattern) made of a copper foil 22 is formed on the surface of the insulating layer 21. ing. Then, the LED chip 2 is mounted on the circuit pattern made of the copper foil 22, and wire bonding is performed between the LED chip 2 and the gold-plated portion (electrode part) of the copper foil 22 with the gold wires 5 and 5. .

  A resist layer 24 is formed on the surface of the circuit pattern of the copper foil 22 excluding the mounting portion of the LED chip 2 (peripheral portion of the LED chip 2) and the wire bonding portion (electrode portion). Note that the material of the substrate 1 may be a metal other than aluminum or copper, a resin, a ceramic, or the like.

  A surrounding portion 26 is provided on the upper surface of the resist layer 24 so as to surround the LED chip 2. The surrounding portion 26 has a predetermined height dimension so as to be higher than the height of the LED chip 2 and the gold wire 5, and can be formed in an annular shape or a rectangular shape having a predetermined width in plan view. For example, the surrounding part 26 can be formed by applying a high-viscosity resin around the LED chip 2 while maintaining a predetermined height with a dispenser, and curing the applied resin. For the surrounding portion 26, for example, a translucent resin such as an epoxy resin or a silicon resin can be used.

  In order to seal the LED chip 2, the gold wire 5, and the wire bonding part (electrode part) inside the enclosure part 26, a light-transmitting resin is filled to form a sealing part 28. The sealing portion 28 is formed in a convex shape in which the thickness of the central portion near the LED chip 2 is higher than the height of the surrounding portion 26, and has, for example, a dome shape.

  The LED chip 2 is an LED chip that generates blue light, and a phosphor that converts blue light into light having a longer wavelength is mixed in the resin that forms the sealed portion 28. Thereby, a part of the blue light generated by the LED chip 2 is wavelength-converted by the phosphor contained in the sealing portion 28 and functions as a white LED that emits white light.

  With the configuration as described above, the LED chip 2 as the light emitting unit can be prevented from directly touching the explosive atmosphere, and the sealed portion 28 (LED chip 2, gold wire) that seals the LED chip 2 on the substrate 1 is sealed. 5, the place where the gold plating of the copper foil 22 and the sealed part thereof can be regarded as the lamp structure 20, and the requirements of the safety explosion-proof structure of the light emitting part can be satisfied.

  FIG. 4 is a cross-sectional view showing an example of the lamp structure 30. As shown in FIG. 4, the lamp structure 30 includes an insulating layer 31 formed on a substrate 1 such as an aluminum substrate or a copper substrate, and a circuit pattern (conductive pattern) formed of a copper foil 32 is formed on the surface of the insulating layer 31. ing. Then, the LED chip 2 is mounted on the circuit pattern made of the copper foil 32, and the wire bonding between the LED chip 2 and the gold-plated portion (electrode part) of the copper foil 32 is performed by the gold wires 5 and 5. .

  On the circuit pattern of the copper foil 32, an insulating substrate 34 such as a glass substrate having an opening opened so as to surround the LED chip 2, the gold wire 5, and the wire-bonded copper foil 32 is covered with an adhesive 33. Bonded. A resist layer 35 is formed on the surface of the insulating substrate 34.

  In the opening of the insulating substrate 34, the circuit pattern by the copper foil 32 is exposed and is surrounded by the side wall of the insulating substrate 34. The LED chip 2 is mounted in the opening, and the LED chip 2 and the gold-plated portion (electrode part) of the copper foil 32 are wire-bonded with gold wires 5 and 5.

  Then, in order to seal the LED chip 2, the gold wire 5, and the wire bonding part (electrode part) inside the opening, the sealing part 38 is formed by filling with a translucent resin. The LED chip 2 is an LED chip that generates blue light, and the resin constituting the sealed portion 38 is mixed with a phosphor that converts blue light into light having a longer wavelength. Thereby, a part of the blue light generated by the LED chip 2 is wavelength-converted by the phosphor contained in the sealing portion 38 and functions as a white LED that emits white light.

  With the above-described configuration, the LED chip 2 as the light emitting unit can be prevented from directly touching the explosive atmosphere, and the sealed portion 38 (LED chip 2, gold wire) that seals the LED chip 2 on the substrate 1 is used. 5, the gold-plated portion of the copper foil 32 and the sealed portion thereof) can be regarded as the lamp structure 30 and the requirements for the safety explosion-proof structure of the light emitting part can be satisfied.

  In the example of FIG. 3 or FIG. 4 described above, a phosphor sheet can be used as in the example of FIG. In the example of FIG. 2, the LED chip 2 and the like can be sealed with a resin containing a phosphor as in the example of FIG. 3 or FIG. 4 instead of the phosphor sheet 7.

  FIG. 5 is an explanatory diagram showing an example of the configuration of the conductive portion 50 of the substrate 1. The conductive portion 50 is a connecting portion that connects the copper foil 3 as a circuit pattern formed on the substrate 1 and the electric wire 60 from the power supply device (power supply portion) for supplying power to the LED chip 2 of the substrate 1. is there. In FIG. 5, the copper foil 3 is formed on both surfaces of the substrate 1, but only one surface may be used.

  As shown in FIG. 5, an insertion hole for inserting the screw 51 is formed in the substrate 1, and the screw 51 through the crimping terminal 61 that is crimped to the tip of the spring washer 53, the flat washer 52, and the electric wire 60 After passing through the insertion hole of the substrate 1, the plain washer 52 and the spring washer 53 are passed through the back side of the substrate 1 and tightened with the nut 54. By mechanically connecting with the screw 51, the nut 54, etc., the copper foil 3 of the board 1 and the electric wire 60 can be reliably connected, and the spring washer 53 functions to loosen. As a result, it is possible to prevent contact failure due to heat generation or vibration at the connection portion between the conductive portion 50 of the substrate 1 provided with the LED chip 2 and the electric wire 60 for supplying power to the LED chip 2. Can meet the requirements of the safety explosion-proof structure.

  The mechanical connection is not limited to screw tightening with the above-described loosening prevention, but may be rivet tightening, crimp connection, or the like. Further, soldering (not only soldering) reinforced with a sleeve, a binding wire or the like may be used.

  In the above-described embodiment, the electrically conductive pattern portions other than the lamp structure (10, 20, 30) of the substrate 1 have an electrical insulation distance (for example, an insulation space distance or a creepage distance) that requires a safety explosion-proof structure. It satisfies the matter.

  FIG. 6 is a schematic diagram showing an example of the structure of the lighting device 200 having the safety explosion-proof structure according to the present invention. The difference from the example of FIG. 1 is that a power supply unit 203 for supplying power to the LED chip 2 on the substrate 1 is incorporated. The same parts as those in the example of FIG. As shown in FIG. 6, the power source unit 203 is accommodated in the container main body 201, and the container lid 202 is attached to the upper part, and the entire container (201, 202) has an explosion-proof structure (for example, a pressure-proof structure). Yes. Although not shown, the electric wire from the power supply unit 203 is connected to the substrate 1 as in the example shown in FIG. In addition, as shown in FIG. 1, a power supply part can also be separately installed outside the illuminating device 100 of a safety explosion-proof structure. In addition, the illumination device 100 in the example of FIG. 1 can achieve a reduction in size and weight and cost as compared with the illumination device 200 in the example of FIG.

  Thereby, it is not necessary to install a power supply unit (power supply device) separately from the illumination device, and a safety-explosion-proof illumination device incorporating the power supply unit can be provided.

  As described above, according to the present invention, it is possible to realize an illumination device having a safety explosion-proof structure using a light emitting diode as a light source. Since the lighting device can be manufactured with a simpler structure than the explosion-proof structure, the cost can be suppressed, and a compact, lightweight, and inexpensive explosion-proof lighting device can be provided.

  In the above-described embodiment, the LED chip as the light emitting part, the gold wire, the electrode part of the copper foil and the like are provided only in the peripheral part of the LED chip, so a plurality of LED chips are provided. In this case, the peripheral portion of each LED chip can have a lamp structure. For example, compared with the case where the whole substrate is sealed, the amount of the synthetic resin as the sealed portion can be reduced, and an increase in weight and cost increase can be suppressed. Moreover, although the sealing part requires an electrical insulating material for protecting the LED chip and the gold wire, it can be used together with this, and the cost can be reduced.

It is a schematic diagram which shows an example of the structure of the illuminating device of the safe explosion-proof structure which concerns on this invention. It is sectional drawing which shows an example of a lamp structure. It is sectional drawing which shows an example of a lamp structure. It is sectional drawing which shows an example of a lamp structure. It is explanatory drawing which shows an example of a structure of the electroconductive part of a board | substrate. It is a schematic diagram which shows an example of the structure of the illuminating device of the safe explosion-proof structure which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 LED chip 3 Thermoplastic resin film board | substrate 3a Insulation film 3b Copper foil (electrode part)
4 Resist layer 5 Gold wire
6 Silicone material 7 Phosphor sheet 8 Silicon potting material (sealed part)
10, 20, 30 Lamp structure 22, 32 Copper foil (electrode part)
28, 38 Sealed part 50 Conductive part 60 Electric wire 201 Container body 202 Container lid part 203 Power supply part

Claims (2)

A substrate,
An LED chip mounted on the substrate,
The electrode portion provided on the substrate and the LED chip are wire bonded,
A lighting device having a safety-explosion-proof structure, comprising a sealing portion made of a synthetic resin that seals the LED chip and the electrode portion. Comprising a conductive part connected to the electrode part via a conductive pattern formed on the substrate;
The conductive part is
The lighting device having a safety explosion-proof structure according to claim 1, wherein the electric wires are mechanically connected.

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