JP2010073464A - Lighting system - Google Patents

Abstract

An object of the present invention is to provide an illuminating device that can improve the heat dissipation performance of a semiconductor light emitting device and can easily obtain desired white light by suppressing leakage light.
The invention according to claim 1 includes a substrate portion 3 having a first surface, a second surface parallel to the surface, and a peripheral surface extending over these surfaces, and an electrically insulating and translucent substrate, and the substrate portion. A substrate 2 provided with a light shielding portion 40 provided on the peripheral surface of the substrate and a heat radiating portion 4 formed of a material having a high thermal conductivity by the substrate portion; and disposed on the first surface having an element electrode. A plurality of semiconductor light-emitting elements; and a phosphor layer provided on substantially the entire first surface so as to cover the plurality of semiconductor light-emitting elements.
[Selection] Figure 2

Description

  The present invention relates to a lighting device having a semiconductor light emitting element such as a plurality of LED (light emitting diode) chips and used for, for example, a lighting fixture or a display.

  For example, an LED backlight described in Japanese Patent Application Laid-Open No. 2006-98500 is mainly composed of a light guide plate and a light source body disposed on an end face of the light guide plate. That is, the light guide plate side includes a lens sheet, a diffusion sheet, and a reflection sheet, and the light source body includes an LED light source that is a light emitting diode module, an insulating substrate, a heat sink substrate having a heat sink function, and a heat conductive elastic sheet. Furthermore, one main surface (surface from which light is emitted) of the light guide plate is disposed so as to face the display area of the liquid crystal display panel.

The light guide plate constituting the LED backlight is made of a transparent resin substrate, and a reflective sheet for diffusing and reflecting light is disposed on the other main surface of the light guide plate. This reflection sheet is for radiating light propagating through the light guide plate to the one main surface side. In addition, you may form the groove | channel for diffusing and reflecting directly on the other main surface instead of a reflection sheet, and may form the coating film which has a spreading | diffusion / reflection function in the other main surface. Moreover, you may form this reflection sheet also in three end surfaces except the end surface in which an LED light source is arrange | positioned among four end surfaces of a light-guide plate.
JP 2006-98500 A (paragraphs 0045-0047, FIG. 1)

  In the LED backlight described in Patent Document 1, the light emitted from the LED light source disposed on the end face of the light guide plate enters the light guide plate, and is repeatedly reflected and applied to the liquid crystal display panel. The reflection sheet is for radiating light propagating through the light guide plate to one main surface side, and is intended to prevent light from leaking from unnecessary portions.

  However, in a lighting device in which a plurality of semiconductor light emitting elements that emit blue light are disposed on a translucent substrate, this element is covered with a phosphor layer that emits yellow light, and both are colored to emit white light in a planar shape. The white light is obtained by constituting a predetermined phosphor layer with respect to a predetermined blue light, and a light-shielding body is disposed on the peripheral surface of the translucent substrate so as to reduce leakage light. It's not a good thing.

  In such an illuminating device, the intensity of blue light and yellow light is controlled within a predetermined range so that the light emitting portion of blue light has approximately the same area as the phosphor layer, and blue light is not reduced under these conditions. In addition, it is required to suppress leakage and improve heat dissipation.

  The objective of this invention is providing the illuminating device which can improve the thermal radiation performance of a semiconductor light-emitting element, and also can suppress desired light and can obtain desired white light easily.

  According to a first aspect of the present invention, there is provided an electrically insulating and translucent substrate portion having a first surface, a second surface parallel to the first surface, and a peripheral surface extending over both surfaces, and provided on the peripheral surface of the substrate portion. A light-shielding portion formed thereon, and a substrate provided with a heat-dissipating portion formed of a material having a high thermal conductivity by the substrate portion; a plurality of semiconductor light-emitting elements disposed on the first surface having element electrodes; And a phosphor layer provided on substantially the entire first surface so as to cover the plurality of semiconductor light emitting elements.

  In the first aspect of the invention, examples of the electrically insulating / translucent insulating material for the substrate portion include transparent glass, transparent acrylic resin, and translucent ceramic. Further, it is specified that the phosphor layer is provided on almost the entire first surface. For example, in the case where a frame for forming the phosphor layer is provided at the end of the substrate portion. In some cases, the installation area of the phosphor layer may be slightly narrower than the area of the first surface of the substrate portion, which is acceptable.

  According to the first aspect of the present invention, the area of the substrate portion is such that the blue light emitting portion has an area substantially equal to that of the phosphor layer so that the intensity of blue light and yellow light is controlled within a predetermined range. In order not to reduce light, leakage light is suppressed by the light shielding portion, and heat dissipation is improved by the heat dissipation portion.

  According to a second aspect of the present invention, in the illumination device according to the first aspect, the heat radiating portion is a plurality of heat exhaust members disposed inside the second surface or the substrate portion. .

  When a substrate provided with a heat exhausting member is used inside the substrate section or on the surface where the semiconductor light emitting element is not mounted, heat conducted from each semiconductor light emitting element to the substrate is exhausted in a state where the plurality of semiconductor light emitting elements emit light. It can guide | induct with a thermal member and can discharge | emit it to the exterior of a board | substrate from the edge part of these exhaust heat members. Thereby, as the temperature rise of the substrate having the substrate portion can be suppressed, the heat radiation from the semiconductor light emitting element to the substrate is maintained, and the temperature rise of each semiconductor light emitting element can be suppressed.

  According to the illuminating device of the first and second aspects of the invention, it is possible to improve the heat dissipation performance of the semiconductor light emitting element, further suppress leakage light, and easily obtain desired white light.

  A first embodiment of the present invention will be described with reference to FIGS. Reference numeral 1 in FIGS. 1 and 2 denotes an illumination device that forms an LED package. The lighting device 1 includes a substrate 2, a plurality of semiconductor light emitting elements such as LED chips (hereinafter abbreviated as LEDs) 7, metal conductors such as bonding wires 11 and 12, a first frame body 14, a second frame body 16, The first phosphor layer 18 and the second phosphor layer 20 are provided.

  The planar view shape of the substrate 2 is, for example, a quadrangle as shown in FIG. The substrate 2 includes a substrate portion 3, a plurality of heat exhausting members 4 as heat radiating portions 4, a pair of electrode patterns 5, and a light shielding portion 40.

  As shown in FIG. 2, the substrate part 3 has a first surface 3a, a second surface 3b parallel to the first surface 3a, and a peripheral surface 3c extending over both surfaces. This board | substrate part 3 has electrical insulation and translucency, and is made from an electrical insulation material, for example, a transparent glass plate. Specifically, a thickness of 0.5 mm to 1.5 mm is provided so as to withstand the first phosphor layer 18 and the second phosphor layer 20 as the phosphor layers at 100 ° C. to 150 ° C. The substrate part 3 is made of transparent quartz glass. The second surface of the quartz glass substrate portion 3 may be subjected to a frost treatment to provide a light diffusion portion (light diffusion layer) or may be subjected to prism cut. As a result, the afterimage (crushing feeling) of the blue light emitted from the LED 7 is alleviated.

  In this embodiment, the light-shielding part 40 is provided with a light-shielding / heat-dissipating member 40 having light-shielding and heat-dissipating properties on the peripheral surface 3 c of the substrate 3. The end 4 a of the heat exhausting member 4 is mechanically connected to the light shielding / radiating member 40. Therefore, the light from each LED 7 is repeatedly reflected inside the substrate 3, but the light shielding / heat dissipating member 40 provided on the peripheral surface 3 c of the substrate 3 radiates the reflected light from the peripheral surface 3 c to the outside. Suppress. Further, the light shielding / radiating member 40 can radiate the heat conducted from the heat exhausting member 4. In addition, the light-shielding part 40 does not need to have heat dissipation in particular.

  The plurality of heat exhaust members 4 are made of metal wires having a circular or square cross section, and are embedded in the substrate portion 3 at regular intervals in the vertical and horizontal directions as shown in FIG. It is arranged. Therefore, as shown in FIG. 1, the grid of grids formed by the exhaust heat members 4 arranged vertically and horizontally, in other words, a space between the adjacent heat exhaust members 4 forms a square. The end 4a of each heat exhaust member 4 protrudes with respect to the peripheral surface 3c.

  In order to prevent the heat removal member 4 and the substrate portion 3 from being peeled off, the linear expansion coefficients of the heat removal member 4 and the substrate portion 3 are substantially the same. Specifically, a tungsten wire whose surface is oxidized is adopted as the exhaust heat member 4.

  As will be described later, the plurality of heat exhaust members 4 disposed in the lateral (left-right) direction in FIG. As shown in FIG. 2, the substrate portion 3 is buried at a position approximately half the thickness direction. At the same time, the plurality of heat exhausting members 4 disposed so as to extend in the vertical (vertical) direction in FIG. 1 with respect to the substrate unit 3 are the heat exhausting members 4 extending in the lateral direction as shown in FIG. It is buried between the second surface 3b.

  Accordingly, the distance between the first surface 3 a and each heat exhaust member 4 is larger than the distance between the second surface 3 b and the heat exhaust member 4. Accordingly, the first surface 3a on which the LED 7 is mounted becomes flat by suppressing the portion of the first surface 3a corresponding to the portion directly above the heat exhaust member 4 from swelling due to the heat exhaust member 4. It is like that.

  The pair of electrode patterns 5 are respectively provided at the left and right end portions of the first surface 3 a of the substrate portion 3. These electrode patterns 5 are made of copper foil or the like, and are formed in a comb shape as shown in FIG. One electrode pattern 5 is for the positive electrode, and the other electrode pattern 5 is for the negative electrode. These electrode patterns 5 are connected to electric wires (not shown) for guiding a direct current supplied from a power supply circuit (not shown).

  For each LED 7, for example, a double wire type using a nitride semiconductor is employed. These LEDs 7 are formed by providing a semiconductor light emitting layer on one surface of a translucent element substrate made of sapphire or the like. The semiconductor light emitting layer emits blue light, for example. The LED 7 emitting blue light has a pair of element electrodes for positive electrode and negative electrode (not shown) on the semiconductor light emitting layer side.

  As shown in FIG. 1, the LEDs 7 are two-dimensionally arranged in rows and columns on the first surface 3 a of the substrate unit 3. Each LED 7 is mounted on the substrate portion 3 by using a light-transmitting die bond material (not shown) on the other surface of the element substrate that is parallel to one surface on which the semiconductor light emitting layer is stacked and on which the semiconductor light emitting layer is not stacked. 1 is bonded to the surface 3a.

  As described above, these LEDs 7 are arranged so as to face the center portion of the grid of the grid as shown in FIG. 1 in the positional relationship with the heat exhaust members 4 arranged in a grid pattern. It is installed. The distance L between each heat exhaust member 4 and the LED 7 (represented by the distance between the lower heat exhaust member 4 and the LED 7 in FIG. 2) is preferably 0.2 mm or more. By doing in this way, even if the first surface 3a is swollen due to the heat exhausting member 4 embedded in the substrate section 3, the LED 7 can be mounted at a position deviated from the swollenness. Thereby, since mounted LED7 does not tilt according to the said swelling, the desired light distribution can be obtained.

  The bonding wires 11 and 12 are made of fine metal wires such as Au wires. The LEDs 7 arranged between the electrode patterns 5 and arranged in the horizontal direction of the substrate 2 are electrically connected in series with bonding wires 11 connected to the element electrodes by wire bonding. .

  Thus, the element electrode of the LED 7 positioned at one end of the LED array formed by the plurality of LEDs 7 connected in series by the bonding wire 11 and the comb-tooth portion of the one electrode pattern 5 are electrically connected by the bonding wire 12. Yes. Similarly, the element electrode of the LED 7 positioned at the other end of each LED row and the comb tooth portion of the other electrode pattern 5 are also electrically connected by the bonding wire 12.

  As shown in FIG. 1, the first frame body 14 has a square frame shape that is large enough to accommodate all LEDs 7 with an electrically insulating material such as a synthetic resin, and is formed on the first surface 3 a of the substrate portion 3. It is mounted using an adhesive. The first frame body 14 is bonded to the first surface 3 a across the comb tooth portions of the pair of electrode patterns 5.

  The second frame 16 is also made of an electrically insulating material such as a synthetic resin. The second frame body 16 is the same size as the first frame body 14, but its thickness is thinner than that of the first frame body 14. The second frame 16 is attached to the second surface 3b of the substrate unit 3 using an adhesive.

  The first phosphor layer 18 is filled in the first frame body 14 in a substantially full state, and seals all the LEDs 7 and bonding wires 11, 12, etc. accommodated in the first frame body 14. Thus, these are protected from moisture, outside air, and the like to prevent a decrease in the lifetime of the lighting device 1. The phosphor layer 18 is provided on almost the entire first surface 3a. In the present embodiment, when the frame body 14 for forming the phosphor layer 18 is disposed at the end of the substrate unit 3, the installation area is slightly larger than the area of the first surface 3 a of the substrate unit 3. This degree can be tolerated.

  Therefore, the blue light emitting portion (first surface 3a of the substrate unit 3) from the LED 7 has an area substantially equal to that of the phosphor layer 18, and the blue light of the LED 7 and the yellow light of the phosphor layer 18 The intensity can be controlled within a predetermined range. Furthermore, while the light shielding part 40 suppresses the blue light leakage of the LED 7, the heat radiation part 4 can improve the heat radiation performance of the LED 7 and easily obtain desired white light.

  The first phosphor layer 18 is made of a translucent material such as a translucent resin, specifically, a thermosetting silicone resin. The first phosphor layer 18 is cured by being injected into the first frame 14 in a non-cured liquid state and then heated in a heating furnace. In the first phosphor layer 18, phosphors (not shown) are preferably mixed in a uniformly dispersed state. The phosphor is excited by a part of the light emitted from each LED 7 and emits light of a color different from the color of the light emitted from the LED 7, and thereby the color of the illumination light emitted from the illumination device 1. Is used to define In the present embodiment, in order to change the color of the illumination light emitted from the illumination device 1 to white light, a phosphor that emits yellow light that is complementary to the blue light emitted by each LED 7 is used. Has been.

  The translucent substrate 30 is made of quartz glass and is provided so as to cover the first phosphor layer 18. Further, on the surface side (outside) of the quartz glass 30, a light diffusing portion (light diffusing layer) may be provided by performing a frost treatment, or a prism cut may be performed. Then, the afterimage (crushing feeling) of the blue light emitted from the LED 7 is alleviated, and moisture or the like is prevented from adhering to the LED 7 and the first phosphor layer 18.

  The second phosphor layer 20 is filled in the second frame 16 in a substantially full state. The second phosphor layer 20 is made of a translucent material, for example, a translucent resin, specifically, a thermosetting silicone resin. The second phosphor layer 20 is cured by being heated in a heating furnace after being injected into the second frame 16 by a predetermined amount in an uncured liquid state.

  Also in the second phosphor layer 20, phosphors (not shown) are preferably mixed in a uniformly dispersed state. In order to change the color of the illumination light emitted from the illumination device 1 to white light in the same manner as the phosphor mixed in the first phosphor layer 18, the phosphor is made of blue light emitted from each LED 7. Thus, a phosphor that emits yellow light having a complementary color relationship is used. Quartz glass may be provided so as to cover the second phosphor layer 20. In this case, moisture or the like can be prevented from adhering to the second phosphor layer 20. Although not shown, a metal heat radiating member formed in a frame shape larger than the substrate 2 may be provided, and the end 4a of the exhaust heat member 4 may be connected to the heat radiating member.

  By supplying power to each LED row of the illumination device 1 having the above-described configuration through the electrode pattern 5, a plurality of LEDs 7 included in these LED rows emit light all at once. Therefore, the blue light emitted upward in FIG. 2 from each LED 7 and the yellow light emitted from the phosphor excited in the first phosphor layer 18 by a part thereof are mixed. 2 is emitted upward in FIG. 2.

  At the same time, since the blue light emitted downward from each LED 7 in FIG. 2 passes through the transparent die-bonding material and the transparent substrate portion 3, the second phosphor is formed by the blue light and a part thereof. White light generated by mixing yellow light emitted from the phosphor excited in the layer 20 is emitted downward in FIG.

  As described above, since the lighting device 1 can extract white light from both surfaces of the substrate 2, it can be suitably used for lighting applications that require such double-sided light emission.

  In this illuminating device 1, the LEDs 7 are disposed so as to face the eyes of the grid pattern formed by the plurality of heat exhaust members 4. Not. Therefore, light can be efficiently taken out from the second surface 3b side of the substrate 2 without being obstructed by the heat exhausting member 4.

  During the above illumination, each LED 7 generates heat. The heat generated by these LEDs 7 is conducted to the electrically insulating substrate 3, and the heat exhaust member 4 is embedded in the substrate 3 in a lattice shape. Therefore, the heat conducted from each LED 7 to the substrate 2 can be guided by the lattice-shaped heat exhaust member 4, and can be quickly discharged from the end 4 a of the heat exhaust member 4 to the heat radiating member outside the substrate 2. Thereby, as the temperature rise of the substrate 2 having the electrically insulating substrate portion 3 can be suppressed, the heat dissipation from the LED 7 to the substrate 2 is maintained, and the temperature rise of each LED 7 can be suppressed. Therefore, a decrease in light emission efficiency of each LED 7 is suppressed.

  Incidentally, as described above, the present embodiment in which a lighting device 1 in which a plurality of heat exhaust members 4 made of tungsten wire are embedded in a lattice pattern in a quartz glass substrate portion 3 is turned on by flowing a rated current (20 mA). Then, it was confirmed that the substrate temperature can be reduced by 10 ° C. to 20 ° C. as compared with the configuration without the exhaust heat member.

  Moreover, since each LED 7 is arrange | positioned facing the center part of the eye of the grid of the plurality of heat exhausting members 4 as described above, the vertical and horizontal positions located so as to surround one LED 7 are arranged. The distance between the exhaust heat member 4 and the LED 7 that it surrounds is equal. Therefore, the dispersion | variation in the heat dissipation from each LED7 to the exhaust heat member 4 is suppressed. As a result, variations in the temperature of each LED 7 are suppressed, and as a result, variations in the light emission luminance of each LED 7 can also be suppressed.

  3 and 4 show a second embodiment of the present invention. Since the second embodiment has the same configuration as that of the first embodiment except for the matters described below, the same components are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  In the second embodiment, the plurality of heat removal members 4 combined in a grid pattern are not embedded in the board part 3, but the surface of the board part 3 opposite to the LED mounting surface (first mounting surface), that is, The heat exhausting member 4 is disposed on the second surface 3b of the substrate unit 3 by adhesion. Therefore, a portion between both end portions 4 a of the heat exhausting member 4, that is, an intermediate portion located in the second frame body 16 is filled with the second phosphor layer 20.

  Furthermore, in 2nd Embodiment, each LED7 is arrange | positioned by the 1st surface 3a of the board | substrate 2 facing the heat exhausting member 4 extended in an up-down direction in FIG. Instead of this, the arrangement of each LED 7 can be arranged so as to oppose the intersecting portion of the vertical and horizontal heat exhaust members 4, and between the adjacent heat exhaust members 4 as in the first embodiment. It is also possible to arrange them facing each other.

  The configuration of the second embodiment is the same as that of the first embodiment except for the matters described above. Therefore, 2nd Embodiment can solve the subject of this invention for the reason already demonstrated in 1st Embodiment. Moreover, in the second embodiment, the flatness of the first surface 3a is easily ensured by disposing the heat exhausting members 4 on the second surface 3b in a lattice pattern. Further, since each LED 7 is disposed so as to face the heat exhausting member 4, the light extraction property from the second surface 3 b side is lowered, but the LED 7 efficiently passes through the substrate portion 3 to the heat exhausting member 4. It is preferable in that heat can be taken out and discharged.

The front view shown in the state which partly cut away the illuminating device which concerns on 1st Embodiment of this invention. Sectional drawing of the illuminating device shown along the arrow F2-F2 line | wire in FIG. The front view shown in the state which partly cut away the illuminating device which concerns on 2nd Embodiment of this invention. Sectional drawing of the illuminating device shown along the arrow F4-F4 line | wire in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 2 ... Board | substrate, 3 ... Board | substrate part, 3a ... 1st surface of a board | substrate part, 3b ... 2nd surface of a board | substrate part, 3c ... Peripheral surface of a board | substrate part, 4 ... Heat exhaust member (radiation part) 4a ... an end of the heat exhausting member, 7 ... an LED (semiconductor light emitting element), 11 ... a bonding wire, 18 ... a phosphor layer, 30 ... a translucent substrate, 40 ... a light shielding part.

Claims (2)

A first surface, a second surface parallel to the first surface, and a substrate portion having electrical insulation and translucency having a peripheral surface extending over both surfaces; a light shielding portion provided on the peripheral surface of the substrate portion; and A substrate provided with a heat dissipation portion formed of a material having a high thermal conductivity by the substrate portion;
A plurality of semiconductor light emitting devices having device electrodes and disposed on the first surface;
A phosphor layer provided on substantially the entire first surface so as to cover the plurality of semiconductor light emitting elements;
An illumination device comprising:   2. The lighting device according to claim 1, wherein the heat dissipating unit is a plurality of heat exhausting members disposed inside the second surface or the substrate unit.

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