JP2012054163A - Light source device and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device excellent in a heat dissipation property and an electronic equipment equipped with such a light source device.SOLUTION: The light source device 1 is provided with a mounting substrate 2, and a light-emitting device 4 fitted on one surface side of the mounting substrate 2 and equipped with a light-emitting diode element 42. The mounting substrate 2 is provided with a plurality of through-holes 251 penetrating in its thickness direction and making air circulated. The plurality of through-holes 251 are fitted to a vicinity part in the vicinity from the light-emitting device 4 in a plane direction of the mounting substrate 2. A ratio of an area occupied by the through-holes 251 to the area of the vicinity part of the mounting substrate 2 in plane view is 0.01% or more and 50% or less.

Description

  The present invention relates to a light source device and an electronic apparatus.

  For example, a light source device using a light emitting diode (LED) element as a light emitting element is known (for example, see Patent Document 1). In such a light source device, generally, a surface mount type light emitting device including an LED chip (LED element) is mounted on one surface side of a substrate.

  Such a light source device is used for, for example, a lighting fixture or a backlight of a liquid crystal display in a state where a substrate (mounting substrate) on which LED elements are mounted is housed in the housing together with the LED elements.

  However, the conventional light source device has a problem in that the heat dissipation is not sufficient, and the heat generated by the light emission of the LED element causes deterioration of the LED element, deterioration of connection reliability with the mounting substrate, and the like. In particular, when a high luminance is required for the LED element, a large current flows through the LED element, so that the amount of heat generated from the LED element is large, and this problem becomes significant.

JP 2009-93926 A

  The objective of this invention is providing the light source device excellent in heat dissipation, and an electronic device provided with this light source device.

Such an object is achieved by the present invention described in the following (1) to (18).
(1) a substrate;
A light-emitting device provided on one surface side of the substrate and including a light-emitting element;
The light source device according to claim 1, wherein the substrate is provided with a plurality of ventilation holes that pass through the substrate in the thickness direction and allow gas to flow therethrough.

  (2) The light source device according to (1), wherein the plurality of vent holes are provided in a proximal portion proximal to the light emitting device in a surface direction of the substrate.

  (3) The light source device according to (2), wherein a ratio of an area occupied by the vent hole to an area of the proximal portion of the substrate in a plan view is 0.01% or more and 50% or less.

(4) The plurality of vent holes are provided in a proximal portion proximal to the light emitting device and a distal portion distal to the light emitting device in the surface direction of the substrate,
The light source device according to any one of (1) to (3), wherein a density of arrangement of the vent holes in the proximal portion is higher than a density of arrangement of the vent holes in the distal portion.

(5) The light source device according to any one of (2) to (4), wherein a distance from a center of the light emitting device to an outer peripheral edge of the proximal portion in a surface direction of the substrate is 5 mm or more and 100 mm or less.
(6) The light source device according to any one of (1) to (5), wherein each of the vent holes has a circular cross-sectional shape.

(7) The light source device according to (6), wherein each of the air holes has a diameter of 0.1 mm to 5 mm.

(8) The light source device according to any one of (1) to (5), wherein a cross-sectional shape of each of the vent holes is a belt shape.

(9) The light source device according to (8), wherein a width of each air hole is 0.01 mm or more and 5 mm or less.

(10) When the distance between the air holes is L [mm] and the thickness of the substrate is t [mm], L × t is 0.1 or more and 50 or less (1) to (1) to The light source device according to any one of (7).

(11) The light source device according to any one of (1) to (10), wherein a gas is circulated from the opposite side of the substrate to the light emitting device side with respect to the air holes.

(12) The light source device according to any one of (1) to (11), further including a pressure difference generating unit that generates a pressure difference between a space on one surface side and a space on the other surface side with respect to the substrate.

(13) The light source device according to (11) or (12), wherein each of the air holes has a portion where a cross-sectional area gradually increases from the light emitting device side to the opposite side of the substrate.

(14) The surface of the substrate opposite to the light emitting device is in contact with an inner peripheral surface of a housing that houses the light emitting device together with the substrate.
Each said vent is a light source device in any one of said (1) thru | or (13) penetrated with the wall part of the said housing | casing.

(15) The light source device according to any one of (1) to (14), wherein an inner metal layer made of a metal material is formed on an inner peripheral surface of each vent hole.

(16) The light source device according to (15), wherein a metal layer made of a metal material is provided on at least one surface of the substrate in contact with the internal metal layer.

(17) The light source device according to (16), wherein a portion of the metal layer that is in contact with the internal metal layer is not electrically connected to the light emitting element.

(18) The light source device according to any one of (1) to (17), which is used as a backlight of a liquid crystal display device.

  According to the light source device of the present invention, gas can be circulated from the space on the one surface side to the space on the other surface side through the air holes provided in the substrate on which the light emitting device is mounted. Thereby, the temperature rise of the atmosphere around the light emitting element can be suppressed, and the heat generated in the light emitting element can be efficiently radiated. Therefore, the light source device of the present invention is excellent in heat dissipation.

  In addition, according to the electronic apparatus of the present invention, since the light source device having excellent heat dissipation is provided, the light source device exhibits excellent light emission characteristics over a long period of time and is excellent in reliability.

It is a perspective view of the liquid crystal television which incorporated the light source device which concerns on 1st Embodiment of this invention. FIG. 2 is a schematic partial cross-sectional view of the liquid crystal television shown in FIG. 1. It is a top view which shows the light source device with which the liquid crystal television shown in FIG. 2 was equipped. FIG. 4 is an enlarged detail view of a light emitting device of the light source device shown in FIG. 3 and its periphery. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is an enlarged detail drawing of the light-emitting device of the light source device which concerns on 2nd Embodiment of this invention, and its periphery. It is a typical cross section of the liquid crystal television which incorporated the light source device which concerns on 3rd Embodiment of this invention. It is sectional drawing (enlarged sectional drawing of a mounting substrate and a housing | casing) of the light source device with which the liquid crystal television shown in FIG. 8 was equipped. It is a top view which shows 4th Embodiment of the light source device of this invention. It is a top view which shows 5th Embodiment of the light source device of this invention. It is sectional drawing (enlarged sectional drawing of a mounting substrate and a housing | casing) of the light source device which concerns on 6th Embodiment of this invention. It is sectional drawing (enlarged sectional drawing of a mounting substrate and a housing | casing) of the light source device which concerns on 7th Embodiment of this invention. It is sectional drawing (enlarged sectional drawing of a mounting substrate and a housing | casing) of the light source device which concerns on 8th Embodiment of this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, a light source device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<First Embodiment>
1 is a perspective view of a liquid crystal television incorporating a light source device according to the first embodiment of the present invention, FIG. 2 is a schematic partial sectional view of the liquid crystal television shown in FIG. 1, and FIG. 3 is a liquid crystal television shown in FIG. FIG. 4 is a plan view showing the light source device provided in FIG. 4, FIG. 4 is an enlarged detailed view of the light emitting device of the light source device shown in FIG. 3 and its surroundings, FIG. FIG. 5 is a sectional view taken along line BB in FIG. 4. In the following description, for convenience of explanation, the upper side of FIGS. 1, 2, 5 and 6 is referred to as “upper”, the lower side is referred to as “lower”, and the left side of FIGS. "The right side is called" Back ".

  As shown in FIG. 1, the light source device 1 is built in a liquid crystal television 100 which is a liquid crystal display device, and can be used as a backlight thereof.

  The liquid crystal television 100 includes a light source device 1, a display unit (liquid crystal cell) 101 disposed on the front side of the light source device 1, a housing 102 that houses the light source device 1 and the display unit 101, and legs that support the housing 102. Part (stand) 103.

  As shown in FIG. 2, the display unit 101 includes a polarizing plate 104, a glass substrate 105, a color filter 106, a protective film 107, a liquid crystal unit 108, a glass substrate 109, and a polarizing plate 110 in order from the front side. . Furthermore, between the polarizing plate 110 and the light source device 1, various optical films (not shown) such as a diffusion plate, a diffusion sheet, a prism sheet, a brightness enhancement film, and a reflection type deflection plate may be provided. The liquid crystal unit 108 includes a thin film transistor (TFT) as a switching element and a liquid crystal layer made of a quasi-isotropic liquid crystal material or the like. The display unit 101 generates an electric field in the thin film transistor and changes the alignment state of the liquid crystal material in the liquid crystal layer by the electric field, thereby changing the color tone to be visually recognized. And the light from the light source device 1 which is a backlight permeate | transmits the display part 101, and the image displayed on the said display part 101 can be visually recognized.

  As shown in FIGS. 3 and 4, the light source device 1 includes a plurality of light emitting devices 4 and a mounting substrate (substrate) 2 on which these light emitting devices 4 are mounted together. Hereinafter, the configuration of each unit will be described.

  Since each light-emitting device 4 has the same configuration, one light-emitting device 4 will be representatively described below.

  The light emitting device 4 generates light emission by electroluminescence (EL) effect and light emission by fluorescence.

  As shown in FIG. 5, the light emitting device 4 includes a package 41 having a recess 411, a light emitting diode element (LED chip) 42 that is a light emitting element provided on the bottom surface of the recess 411 of the package 41, and a light emitting diode element 42. And a pair of external terminals 44 provided at the bottom of the package 41.

  The package 41 is a small piece made of an insulating material such as a resin material or a ceramic material. The package 41 is provided with wiring (not shown) that electrically connects the light emitting diode element 42 and the pair of external terminals 44.

  The light emitting diode element 42 is formed by forming a semiconductor such as GaAlN, ZnS, ZnSe, SiCGaP, GaAlAs, AlN, InN, AlInGaP, InGaN, GaN, and AlInGaN on the package 41 as a light emitting layer. In the present embodiment, the light emitting diode element 42 that emits light having a wavelength that can excite a phosphor material contained in the light-transmitting resin portion 43 described later is used. More specifically, the light emitting diode element 42 that emits blue light is used.

  The translucent resin portion 43 is composed mainly of a resin material such as an epoxy resin, a modified epoxy resin, a silicone resin, a modified silicone resin, an acrylate resin, a urethane resin, or a polyimide resin having transparency.

  In the present embodiment, the translucent resin portion 43 includes a phosphor material that is excited by the light from the light emitting diode element 42 and emits yellow light.

  The translucent resin portion 43 has a function of protecting the light emitting diode element 42 from external force, dust, moisture, and the like.

  The pair of external terminals 44 is composed of a conductive material as a main material. One external terminal 44 is an anode electrode (anode), and the other external terminal 44 is a cathode electrode (cathode). . Each external terminal 44 is composed mainly of a metal material such as Al, Ti, Fe, Cu, Ni, Ag, Au, and Pt. Each external terminal 44 is electrically connected (contacted) to a circuit pattern 231 (first metal layer 23) provided on the mounting substrate 2 by solder (not shown). Furthermore, the circuit pattern 231 is electrically connected to a power source (not shown).

  In such a light emitting device 4, when a voltage is applied to the light emitting diode element 42 via the pair of external terminals 44, light emission based on the electroluminescence effect occurs in the light emitting diode element 42. By this light emission, the light is transmitted through the translucent resin portion 43 and emitted to the outside. At this time, a part of the light is reflected on the inner wall surface of the recess 411 of the package 41, then passes through the translucent resin portion 43 and is emitted to the outside.

  Further, the light emitting device 4 emits blue light by the EL effect of the light emitting diode element 42, and the translucent resin portion 43 is excited by a part of the blue light to emit yellow light by fluorescence, and has a complementary color relationship. White light is emitted by mixing these blue light and yellow light.

  In addition, the light emitting diode element 42 is not limited to the above-mentioned thing, For example, a monochromatic light emitting diode element, such as red, blue, and green, may be sufficient. In this case, the phosphor material may be omitted from the translucent resin portion 43. The light emitting device 4 may have a plurality of light emitting diode elements. In this case, the emission colors may be the same or different from each other.

  Such a light emitting device 4 is mounted on the mounting substrate 2. As shown in FIG. 3, the mounting substrate 2 has a long plate shape. The light emitting devices 4 are arranged at equal intervals along the longitudinal direction of the mounting substrate 2.

  As shown in FIGS. 5 and 6, the mounting substrate 2 includes a first base material layer (base material layer) 21 and second base material layers (bases) formed on both surfaces of the first base material layer, respectively. Material layers) 22a and 22b, a first metal layer (metal layer (front side metal layer)) 23 formed on the upper surface (one surface) of the second base material layer 22a, and a second base material layer 22b It is the laminated board which has the 2nd metal layer (back side metal layer) 24 formed in the lower surface (other side) of this. This mounting substrate 2 is an example using a so-called glass composite substrate “CEM-3”.

  Each of the first base material layer 21, the second base material layer 22a, and the second base material layer 22b is a layer (insulating layer) formed by impregnating a fiber base material with a resin material.

  The fiber substrate is not particularly limited, and examples thereof include glass fiber substrates such as glass woven fabrics, glass nonwoven fabrics, and glass papers, and woven fabrics and nonwoven fabrics composed of organic fibers such as paper (pulp), aramid, polyester, and fluororesin. Woven fabrics, nonwoven fabrics, mats and the like made of metal fibers, carbon fibers, mineral fibers and the like. These substrates may be used alone or in combination. In particular, it is preferable to use a glass nonwoven fabric for the first base material layer 21 and a glass woven fabric for the second base material layers 22a and 22b.

  The resin material to be impregnated into the fiber base material is preferably a thermosetting resin, such as an epoxy resin, a phenol resin, a urea resin, a melamine resin, a polyester (unsaturated polyester) resin, a polyimide resin, a silicone resin, and a polyurethane resin. Among them, one or two or more of these can be mixed and used, and among these, an epoxy resin is more preferable.

  Further, when the fiber base material constituting the first base material layer 21 is impregnated with a resin material, the resin material includes, for example, a metal oxide such as alumina, a metal hydroxide such as aluminum hydroxide, and nitriding. It is also possible to fill an electrically insulating and highly heat conductive filler (inorganic filler) typified by a nitride such as boron.

  In the mounting substrate 2, the heat generated as each light emitting device 4 emits light is transmitted from the first metal layer 23 to the second base material layer 22 a, the first base material layer 21, and the second base material layer. It is reliably transmitted in the order of 22b, that is, in the direction away from the light emitting device 4 (the surface direction and the thickness direction of the mounting substrate 2).

  Further, as described above, it is preferable to use a glass nonwoven fabric for the first base material layer 21 and a glass woven fabric for the second base material layers 22a and 22b. Since the glass nonwoven fabric can carry a larger amount of a resin material having a higher thermal conductivity than the glass woven fabric, the first nonwoven fabric layer 21 located on the innermost side of the mounting substrate 2 is used to emit light in particular in the surface direction. The heat from the device 4 is diffused. Thereby, heat dissipation efficiency improves.

The average thickness t _total of the entire mounting substrate 2 is not particularly limited, and is preferably 0.1 mm or more and 2.0 mm or less, and more preferably 0.4 mm or more and 1.2 mm or less.

The first average of the base layer 21 thickness t ₁ and the second base layer 22a, the magnitude relation of the average thickness t ₂ of 22b is not particularly limited, the thickness direction of the mounting substrate 2 From the viewpoint of improving the thermal conductivity at, it is preferable that t ₁ ≧ t ₂ .

The thickness _{t 1,} not particularly limited, for example, is preferably at 0.1mm or more 1.2mm or less, more preferably 0.2mm or more 0.8mm or less.

The thickness _{t 2,} not particularly limited, for example, is preferably at 0.4mm less than 0.04 mm, and more preferably 0.1mm or more 0.2mm or less.

  A first metal layer 23 is laminated on the second base material layer 22a, and a second metal layer 24 is laminated on the second base material layer 22b. Each of the first metal layer 23 and the second metal layer 24 is a layer made of a metal material.

  The metal material constituting the first metal layer 23 is not particularly limited, and for example, one type selected from the group consisting of copper, iron, aluminum, indium, tin, lead, silver, zinc, bismuth, and antimony or Examples thereof include conductive materials obtained by combining two or more kinds, and among these, copper is particularly preferable. Copper is excellent not only in electrical conductivity but also in thermal conductivity, and can reliably transfer the heat from each light emitting device 4 to the second base material layer 22 a under the first metal layer 23.

  The metal material constituting the second metal layer 24 is not particularly limited. For example, the same metal material as that constituting the first metal layer 23 can be used, but copper and aluminum are used. preferable. Aluminum and copper are excellent in thermal conductivity, and can reliably dissipate heat transmitted through the second base material layer 22b.

  The first metal layer 23 and the second metal layer 24 may be made of the same metal material or may be made of different metal materials. In the case where the first metal layer 23 and the second metal layer 24 are made of the same metal material, for example, each of the first metal layer 23 and the second metal layer 24 can be made of copper. One metal layer 23 can be made of copper, and the second metal layer 24 can be made of aluminum.

  Further, the method for forming the first metal layer 23 and the second metal layer 24 is not particularly limited, and examples thereof include metal foil bonding (adhesion), metal plating, vapor deposition, sputtering, and printing. .

  As shown in FIG. 4, the first metal layer 23 is patterned into a predetermined shape. Thereby, the 1st metal layer 23 can be divided into the circuit pattern 231 which functions as an electric circuit, and the heat transfer pattern 232 which has a heat transfer function. The circuit pattern 231 is electrically connected to the external terminal 44 of each light emitting device 4 via, for example, solder. Thereby, power is supplied via the circuit pattern 231. The heat transfer pattern 232 is in contact with (in contact with) the back surface of the package 41 of each light emitting device 4. Thereby, the heat generated in each light emitting device 4 can be reliably transmitted to each ventilation portion 25 described later via the heat transfer pattern 232.

  In addition, it does not specifically limit as a patterning method to the 1st metal layer 23, For example, methods, such as an etching, printing, masking, can be used. By such a patterning method, the circuit pattern 231 and the heat transfer pattern 232 can be collectively formed.

  Further, for example, the occupation ratio of the first metal layer 23 with respect to the entire upper surface of the mounting substrate 2 is preferably 50% or more, and more preferably 80% or more and 99% or less. Thereby, the area of the heat transfer pattern 232 can be ensured to such an extent that the heat generated in each light emitting device 4 can be reliably transmitted to each ventilation portion 25. Further, when etching is used as a patterning method for the first metal layer 23, the portion of the first metal layer 23 to be removed by the etching is relatively small. Can do.

  On the other hand, the second metal layer 24 does not function as an electric circuit. That is, the second metal layer 23 is not electrically connected to the circuit pattern 231 of the first metal layer 23 described above, and is not used for transmission of an electric signal (current). The second metal layer 24 may be divided into a plurality of parts so as to be separated from each other, and the circuit pattern 231 may be electrically connected to a part of the second metal layer 24. In this case, a part thereof may be grounded.

The thickness _{t 3} of the first metal layer 23, the thickness _{t 4} of the second metal layer 24, respectively, is not particularly limited, a degree more than 30μm or less 5 [mu] m.

  Now, as shown in FIG. 3, the mounting substrate 2 is provided with a large number of ventilation portions 25 arranged in a matrix. Each ventilation part 25 distribute | circulates gas (specifically the air around the light source device 1), respectively. In the present embodiment, each ventilation portion 25 also has a function of transferring heat generated in the light emitting device 4 to the lower surface side of the mounting substrate 2, that is, to the second metal layer 24. That is, each ventilation part 25 is a thermal via configured similarly to a heat transfer part 28 described later.

  As shown in FIGS. 5 and 6, each of the ventilation portions 25 includes a through hole (vent hole) 251 that penetrates the mounting substrate 2 in the thickness direction along with the first metal layer 23, and an inside of the through hole 251. It is comprised with the internal metal layer 252 formed in the surrounding surface. The inner metal layer 252 is connected (contacted) to the first metal layer 23 and the second metal layer 24, respectively.

  The ventilation portion 25 having such a configuration allows gas to flow from the space on one surface side to the space on the other surface side with respect to the mounting substrate 2 through each through hole 251 provided in the mounting substrate 2 on which the light emitting device 4 is mounted. It can be distributed. Thereby, the temperature rise of the atmosphere around the light emitting diode element 42 can be suppressed, and the heat generated in the light emitting diode element 42 can be efficiently radiated. Therefore, the light source device 1 is excellent in heat dissipation.

  In the present embodiment, the heat from each light emitting device 4 is reliably transmitted to the second metal layer 24 through the internal metal layer 252 and is radiated by the second metal layer 24. . Further, by providing the through hole 251, the surface area of the second metal layer 24 (or the first metal layer 23) is improved, and the heat dissipation efficiency of the light emitting device 4 is improved. Furthermore, the heat of the internal metal layer 252 is taken away by the gas flowing through the through hole 251. From such a thing, the heat dissipation of the light source device 1 can be improved.

  Further, as shown in FIG. 6, the internal space of the liquid crystal television 100 (more specifically, the internal space of the housing 102) is partitioned into a front-side space 111 and a back-side space 112 by the mounting substrate 2. . When each light emitting device 4 generates heat by light emission, the air in the front space 111 is heated. At this time, a temperature difference occurs between the front side space 111 and the back side space 112. In the present embodiment, due to the temperature difference (temperature gradient), the air in the back space 112 flows into the front space 111 through the ventilation portions 25 of the high density region 26. This reliably prevents heat from being accumulated in the front space 111.

  The cross-sectional shape of each through-hole 251 is circular. Each vent hole 251 having such a cross-sectional shape can be formed relatively easily.

  In addition, although the shape (transverse cross-sectional shape) of each through-hole 251 in a plan view is a circle in the present embodiment, the shape is not limited thereto, and may be, for example, a polygon such as an ellipse or a quadrangle. .

  In the present embodiment, each through-hole 251 has a constant diameter (width) over the entire area of the mounting substrate 2 in the thickness direction. That is, in this embodiment, each through hole 251 has a cylindrical shape.

  A method for forming the through hole 251 is not particularly limited, and examples thereof include drilling, router processing, punching processing, and laser processing.

  The internal metal layer 252 is made of a metal material, and for example, the same material as that of the first metal layer 23 and the second metal layer 24 can be used. A method for forming the internal metal layer 252 is not particularly limited, and examples thereof include metal plating, vapor deposition, and sputtering.

  Further, the diameter (inner diameter) of each through hole 251 is not particularly limited as long as the gas can be circulated between the space 111 and the space 112 as described above, but is 0.1 mm or more and 5 mm or less. Preferably, it is 0.2 mm or more and 4 mm or less, more preferably 0.3 mm or more and 3 mm or less. Thereby, the gas can be smoothly circulated through each through-hole 251 while ensuring the area necessary for circuit formation of the mounting substrate 2 and the mechanical strength that can withstand the use.

  As shown in FIG. 1, in the ventilation part 25 having the above-described configuration, the arrangement density changes stepwise along the surface direction of the mounting substrate 2, that is, the arrangement density is high or low (dense / dense). There is. Accordingly, the mounting substrate 2 is divided into a high density region 26 in which the ventilation portion 25 is disposed at a high density and a low density region 27 in which the ventilation portion 25 is disposed at a lower density than the high density region 26. The high density region 26 is a proximal portion proximal from the light emitting device 4 in the surface direction of the mounting substrate 2, and the low density region 27 is a distal portion distal to the light emitting device 4.

  And the arrangement density of the ventilation part 25 in the high density area | region 26 (proximal part) is 1.1 times or more and 100 times or less of the arrangement density of the ventilation part 25 in the low density area | region 27 (distal part). It is preferable that it is 2 times or more and 25 times or less. In addition, the number of the ventilation parts 25 is not limited to the thing of illustration.

In the high-density region 26, when the distance between the through holes 251 is L [mm] and the thickness of the mounting substrate (t ₂ + t ₁ + t ₂ shown in FIG. 5) is t [mm], L × t is preferably 0.1 or more and 50 or less, and more preferably L × t is 0.5 or more and 10 or less. When L × t is in the range as described above, the gas can be smoothly circulated in each through-hole 251 while ensuring the area necessary for circuit formation of the mounting substrate 2 and the mechanical strength that can withstand use. it can.

  In addition, for example, when the light emitting device 4 has a side of 5 mm or more and 20 mm or less, the high density region 26 is preferably a region within a range of 5 mm or more and 100 mm or less centering on the light emitting device 4. It is more preferable that the region be in the range of 50 mm or less. That is, the distance from the center of the light emitting device 4 to the outer peripheral edge of the high-density region 26 (proximal portion) in the surface direction of the mounting substrate 2 is preferably 5 mm or more and 100 mm or less, and is preferably 10 mm or more and 50 mm or less. More preferred. Thereby, the temperature rise of the light-emitting device 4 vicinity can be suppressed effectively.

  By providing a plurality of through holes 251 in such a high-density region 26, a temperature rise in the vicinity of the light emitting device 4 can be effectively suppressed.

  Further, since the arrangement density of the plurality of through holes 251 is high or low, the temperature rise in the vicinity of the light emitting device 4 is effectively suppressed, and the temperature rise is suppressed over a wide range in the surface direction of the mounting substrate 2. be able to. Further, in the present embodiment, since the inner metal layer 252 is provided on the inner peripheral surface of the through-hole 251, the light emitting device 4 has a high density region 26 in which the light emitting device 4 is disposed. Heat transfer to the layer 24 is facilitated. Then, due to the synergistic effect of this heat transfer promotion and the heat transfer action to the second metal layer 24 in the first base material layer 21 and the second base material layers 22a and 22b described above, It is reliably transmitted by the second metal layer 24 and radiated by the second metal layer 24. Thus, the light source device 1 is extremely excellent in heat dissipation.

  Further, as shown in FIG. 4, in the high density region 26, three heat transfer portions 28 that overlap the light emitting device 4 in a plan view are provided. These heat transfer units 28 preferably have an occupation ratio with respect to the area of the light emitting device 4 in plan view of 0.01% or more, and more preferably 0.02% or more and 50% or less. Thereby, the heat from the light emitting device 4 can be directly guided to the heat transfer section 28, and thus the thermal conductivity in the high density region 26 is improved. In addition, although the number of the heat-transfer parts 28 is three in the structure shown in FIG. 4, it is not limited to this, For example, one, two, or four or more may be sufficient. Further, the heat transfer section 28 may be omitted. Further, in the present embodiment, each heat transfer section 28 includes a through hole 281 and an internal metal layer 282, similar to each ventilation section 25 described above. Each of the heat transfer units 28 has a main purpose of promoting heat transfer from the light emitting device 4 to the second metal layer 24. However, the heat transfer unit 28 may have a function of circulating a gas in the same manner as the ventilation unit 25 described above. it can. In this case, for example, a gap may be provided between the heat transfer unit 28 and the light emitting device 4.

  Further, the ratio of the area occupied by the through holes 251 to the area of the high density region 26 (proximal portion) of the mounting substrate 2 in plan view (the total area of the through holes 251 existing in the high density region 26) is 0.01. % Or more and 50% or less is preferable, and 0.02% or more and 50% or less is more preferable. Thereby, the gas can be smoothly circulated through each vent hole 251 while ensuring the area necessary for circuit formation of the mounting substrate 2 and the mechanical strength that can withstand the use. Further, in the present embodiment, heat generated from each light emitting device 4 (light emitting diode element 42) can be reliably conducted outward.

  On the other hand, the ratio of the area occupied by the through holes 251 to the area of the low density region 27 (distal portion) of the mounting substrate 2 in a plan view (the total area of the through holes 251 existing in the low density region 27) is 0.01. % Or more and 50% or less is preferable, and 0.02% or more and 10% or less is more preferable.

  According to the light source device 1 as described above, the space on the one surface side with respect to the mounting substrate 2 through the through holes 251 (air holes) of the ventilation portions 25 provided in the mounting substrate 2 on which the light emitting device 4 is mounted. Gas can be circulated from the space to the space on the other surface side. Thereby, the temperature rise of the atmosphere around the light emitting diode element 42 (around the light emitting device 4) can be suppressed, and the heat generated in the light emitting diode element 42 can be efficiently radiated. Therefore, the light source device 1 is excellent in heat dissipation. Thereby, the luminous efficiency of each light-emitting device 4 can be improved, and the drive voltage can be lowered. That is, it is possible to provide the light source device 1 with high brightness and long life.

  Moreover, the liquid crystal television 100 (electronic device) provided with such a light source device 1 exhibits excellent light emission characteristics over a long period of time, and is excellent in reliability.

Second Embodiment
FIG. 7 is an enlarged detailed view of the light emitting device of the light source device according to the second embodiment of the present invention and its periphery.

  Hereinafter, the second embodiment of the light source device of the present invention will be described with reference to this drawing, but the description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted.

  The present embodiment is the same as the first embodiment described above except that the configuration of the ventilation holes (venting portions) is different.

  As shown in FIG. 7, in the light source device 1A of the present embodiment, the light emitting device 4 is mounted on the mounting substrate 2A, and the mounting substrate 2A is provided with a plurality of ventilation portions 25A having a band shape in plan view. It has been.

  Each ventilation portion 25A has a through hole (vent hole) 251A that penetrates the mounting substrate 2A in the thickness direction together with the first metal layer 23, and an inner metal layer 252A formed on the inner peripheral surface of the through hole 251A. It consists of and.

  In this embodiment, each through-hole 251A has a strip shape extending straight in a plan view, and the plurality of such through-holes 251 are formed to extend in the same direction. Each through hole 251A may have, for example, a curved or bent portion in plan view.

  Such a through hole 251 having a cross-sectional shape can be formed relatively easily. Further, the through-hole 251A having such a cross-sectional shape can generate a curtain-like airflow. Therefore, it is possible to easily generate convection that flows in a desired direction suitable for heat dissipation.

  Further, the width of each through-hole 251A is more preferably 0.01 mm or more and 5 mm or less, and further preferably 0.2 mm or more and 4 mm or less. Thereby, the gas can be smoothly circulated through each through hole 251A while ensuring the area necessary for circuit formation of the mounting substrate 2A and the mechanical strength that can withstand the use.

  Even with the light source device 1A according to the second embodiment as described above, the temperature increase of the atmosphere around the light emitting device 4 is suppressed by the flow of the gas in the ventilation portion 25A, and the heat generated in the light emitting diode element 42 is efficiently generated. Heat can be released.

<Third Embodiment>
FIG. 8 is a schematic cross-sectional view of a liquid crystal television incorporating a light source device according to a third embodiment of the present invention, and FIG. 9 is a cross-sectional view of the light source device provided in the liquid crystal television shown in FIG. FIG.

  Hereinafter, the third embodiment of the light source device of the present invention will be described with reference to this figure, but the description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted.

  This embodiment is the same as the first embodiment described above, except that a through hole is provided integrally with a housing containing the light source device.

  As shown in FIG. 8, the liquid crystal television 100B of the present embodiment includes a light source device 1B, a display unit (liquid crystal cell) 101 disposed on the front side of the light source device 1B, and a housing that houses the light source device 1B and the display unit 101. The body 102B and the pressure difference generating means 3 are provided.

  The light source device 1B includes a mounting substrate 2 and a plurality of light emitting devices 4, and the housing 102B accommodates the light emitting device 4 together with the mounting substrate 2. Further, the surface of the mounting substrate 2 opposite to the light emitting device 4 is in contact with the inner peripheral surface of the housing 102B.

  As shown in FIG. 9, the housing 102 </ b> B is formed with through holes 1022 that communicate with the through holes 251 of the mounting substrate 2. This through hole 1022 is formed integrally with the corresponding through hole 251. That is, each through-hole 251A penetrates the wall 1021 of the housing 102B. Thereby, even when the mounting substrate 2 is in contact with the inner peripheral surface of the housing 102 </ b> B, the gas can be circulated through each through hole 251 through each through hole 1022.

  In the present embodiment, an internal metal layer 1024 is formed on the inner peripheral surface of each through hole 1022. The inner metal layer 1024 is in contact with the inner metal layer 252 of the ventilation portion 25. Thereby, even if the housing 102B is made of, for example, a resin material and has low thermal conductivity, the heat of the light emitting device 4 can be released to the outside of the housing 102B. Note that the inner metal layer 1024 and the inner metal layer 252 may be integrally formed.

  Further, the housing 102B is provided with an exhaust port 1023 for exhausting gas (air) in the internal space, and the pressure difference generating means 3 is provided in the vicinity of the exhaust port 1023.

  In the present embodiment, the pressure difference generating means 3 is constituted by an exhaust fan, and exhausts the gas in the housing 102B from the exhaust port 1023. Thereby, the pressure difference generating means 3 can generate a pressure difference inside and outside the housing 102B. That is, the pressure difference generating means 3 generates a pressure difference between the space on one surface side of the mounting substrate 2 and the space on the other surface side.

  More specifically, by the operation of the pressure difference generating means 3, the pressure in the space 111 </ b> B (the internal space of the housing 102 </ b> B) on the light emitting device 4 side with respect to the mounting substrate 2 is changed to the side opposite to the light emitting device 4 with respect to the mounting substrate 2. The pressure is made lower than the pressure in the space 112B (the outer space of the housing 102B) (set to a negative pressure). Thereby, gas can be circulated through each of the through holes 251 and 1022 in a desired direction (in this embodiment, from the outer space side to the inner space side of the housing 102B). Further, since the gas is forcibly circulated by the pressure difference generating means 3 as described above, it is possible to increase the flow rate of the gas or increase the flow rate of the gas. Therefore, the heat dissipation effect (cooling effect) of the light emitting device 4 is enhanced.

  In particular, in this embodiment, the gas is circulated from the opposite side (that is, the back surface side) of the mounting substrate 2 to the light emitting device 4 side (that is, the front surface side) with respect to the through holes 251 and 1022. The relatively cool gas in the external space of the housing 102B can be introduced near the light emitting device 4 in the housing 102B. Therefore, a temperature rise near the light emitting device 4 can be efficiently suppressed.

  Even with the light source device 1B according to the third embodiment as described above, the temperature of the atmosphere around the light emitting device 4 is suppressed by the circulation of the gas in the ventilation portion 25, and the heat generated in the light emitting diode element 42 is efficiently generated. Heat can be released.

<Fourth embodiment>
FIG. 10 is a plan view showing a fourth embodiment of the light source device of the present invention.

  Hereinafter, the fourth embodiment of the light source device of the present invention will be described with reference to this drawing. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.

This embodiment is the same as the first embodiment except that the arrangement of the light emitting devices is different.
As shown in FIG. 10, in the light source device 1 </ b> C, four light emitting devices 4 are arranged in a matrix of 2 rows and 2 columns in the high density region 26. The two light emitting devices 4 on the diagonal side emit green monochromatic light. Of the remaining two light emitting devices 4, one light emitting device 4 emits red monochromatic light, and the other light emitting device 4 emits blue monochromatic light. And these four light-emitting devices 4 can light-emit white light as a whole by light-emitting simultaneously. Further, the color temperature of these four light emitting devices 4 can be adjusted by adjusting each of the light emitting devices 4.

  Even with the light source device 1C according to the fourth embodiment as described above, the temperature of the atmosphere around the light emitting device 4 is suppressed by the circulation of the gas in the ventilation portion 25, and the heat generated in the light emitting diode element 42 is efficiently generated. Heat can be released.

<Fifth Embodiment>
FIG. 11 is a plan view showing a fifth embodiment of the light source device of the present invention.

  Hereinafter, the fifth embodiment of the light source device of the present invention will be described with reference to this drawing. However, the difference from the above-described embodiment will be mainly described, and description of similar matters will be omitted.

This embodiment is the same as the first embodiment except that the arrangement of the heat transfer section is different.
As shown in FIG. 11, in the light source device 1 </ b> D, a large number of ventilation portions 25 are arranged radially around the light emitting device 1, and the arrangement density gradually changes along the surface direction of the mounting substrate 2. Yes.

  Even with the light source device 1D according to the fifth embodiment as described above, the temperature of the atmosphere around the light emitting device 4 is suppressed by the circulation of the gas in the ventilation portion 25, and the heat generated in the light emitting diode element 42 is efficiently generated. Heat can be released.

<Sixth Embodiment>
FIG. 12 is a cross-sectional view (enlarged cross-sectional view of the mounting substrate and the housing) of the light source device according to the sixth embodiment of the present invention.

  Hereinafter, the sixth embodiment of the light source device of the present invention will be described with reference to this drawing. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.

  This embodiment is the same as the first embodiment described above, except that a through hole is provided integrally with a housing containing the light source device. Further, the present embodiment is the same as the third embodiment described above except that the shape of the air holes (through holes) provided in the housing is different.

  As shown in FIG. 12, in the light source device 1 </ b> E of the present embodiment, a through hole 1022 </ b> E communicating with each through hole 251 of the mounting substrate 2 is formed in the wall 1021 </ b> E of the housing 102 </ b> E that houses the light emitting device 4 together with the mounting substrate 2. Is formed. In the present embodiment, an internal metal layer 1024E is formed on the inner peripheral surface of each through hole 1022E.

  In particular, in the present embodiment, the width of the through hole 1022E of the housing 102E is gradually reduced from the back surface side (outside) to the front surface side (inside). The through hole 1022E is formed so as to be continuously connected to the through hole 251. Thereby, the gas outside the housing 102E can be smoothly introduced into the through hole 1022E. The flow rate of the gas flowing from the outside to the inside through the through hole 1022E is increased. Therefore, the flow rate of the gas flowing through the through hole 251 is also increased, and the heat dissipation effect of the light emitting device 4 can be improved.

  Even with the light source device 1E according to the sixth embodiment as described above, the temperature of the atmosphere around the light emitting device 4 is suppressed by the flow of the gas in the ventilation portion 25, and the heat generated in the light emitting diode element 42 is efficiently generated. Heat can be released.

<Seventh embodiment>
FIG. 13 is a cross-sectional view (an enlarged cross-sectional view of a mounting substrate and a housing) of a light source device according to a seventh embodiment of the present invention.

  Hereinafter, the seventh embodiment of the light source device of the present invention will be described with reference to this drawing. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.

  This embodiment is different from the shape of the vent hole (through hole) provided in the light source device, and the first embodiment described above except that the through hole is provided integrally with the housing incorporating the light source device. It is the same. Further, the present embodiment is the same as the sixth embodiment described above except that the shape of the vent hole (through hole) provided in the light source device is different.

  As shown in FIG. 13, in the light source device 1F of the present embodiment, a plurality of light emitting devices 4 are mounted on a mounting substrate 2F, and these are housed in a housing 102E.

  The mounting board 2F is provided with a plurality of ventilation portions 25F. Each of the ventilation portions 25F includes a through hole (vent hole) 251F that penetrates the mounting substrate 2F in the thickness direction together with the first metal layer 23, and an internal metal layer 252F formed on the inner peripheral surface of the through hole 251F. It consists of and.

  In the present embodiment, each through hole 251F has a width (inner diameter) that gradually increases from the side opposite to the light emitting device 4 of the mounting substrate 2F toward the light emitting device 4 side.

  The narrow end (end opposite to the light emitting device 4) of each through hole 251F is connected to the inner end of the through hole 1022E provided in the wall 1021E of the housing 102E. Thereby, the through-hole 251F and the through-hole 1022E are connected.

  In such a light source device 1F, since the through-hole 251F and the through-hole 1022E have a form like a Laval nozzle, the compressed gas is circulated through the through-hole 1022E from the outside to the inside effectively in the through-hole 251F. Adiabatic expansion is possible. Therefore, the temperature of the gas discharged from the through hole 251F into the housing 102E can be lowered, and the heat dissipation effect of the light emitting device 4 can be improved.

  Also with the light source device 1F according to the seventh embodiment as described above, the temperature increase of the atmosphere around the light emitting device 4 is suppressed by the circulation of the gas in the ventilation portion 25F, and the heat generated in the light emitting diode element 42 is efficiently performed. Heat can be released.

<Eighth Embodiment>
FIG. 14 is a cross-sectional view (enlarged cross-sectional view of a mounting substrate and a housing) of a light source device according to an eighth embodiment of the present invention.

  Hereinafter, the eighth embodiment of the light source device of the present invention will be described with reference to this drawing. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.

  This embodiment is different from the shape of the vent hole (through hole) provided in the light source device, and the first embodiment described above except that the through hole is provided integrally with the housing incorporating the light source device. It is the same. Further, the present embodiment is the same as the third embodiment described above except that the shape of a vent hole (through hole) provided in the light source device is different.

  As shown in FIG. 14, in the light source device 1G of the present embodiment, a plurality of light emitting devices 4 are mounted on a mounting substrate 2G, and these are housed in a housing 102G.

  A plurality of ventilation portions 25G are provided on the mounting substrate 2G. Each ventilation portion 25G has a through hole (vent hole) 251G that penetrates the mounting substrate 2G in the thickness direction together with the first metal layer 23, and an internal metal layer 252G formed on the inner peripheral surface of the through hole 251G. It consists of and.

  In the present embodiment, the width (inner diameter) of each through hole 251G gradually decreases from the side opposite to the light emitting device 4 of the mounting substrate 2G toward the light emitting device 4 side.

  The wide end of each through hole 251G (the end opposite to the light emitting device 4) is connected to the inner end of the through hole 1022G provided in the wall 1021G of the housing 102G. Thereby, the through hole 251G and the through hole 1022G communicate with each other. In the present embodiment, an internal metal layer 1024G is formed on the inner peripheral surface of each through hole 1022G.

  In such a light source device 1G, the inner diameter (width) of the gas introduction side end (end opposite to the light emitting device 4) of the through hole 251G of the light source device 1G can be increased. Therefore, gas can be smoothly introduced into the through hole 251G through the through hole 1022G. In addition, the gas flow rate can be increased by passing the gas through the through-hole 251G.

  Even with the light source device 1G according to the eighth embodiment as described above, the temperature increase of the atmosphere around the light emitting device 4 is suppressed by the flow of the gas in the ventilation portion 25G, and the heat generated in the light emitting diode element 42 is efficiently generated. Heat can be released.

  The light source device of the present invention has been described above with respect to the illustrated embodiment. However, the present invention is not limited to this, and each part constituting the light source device has an arbitrary configuration that can exhibit the same function. Can be substituted. Moreover, arbitrary components may be added.

  Further, the light source device of the present invention may be a combination of any two or more configurations (features) of the above embodiments.

  In addition to the liquid crystal television, examples of the liquid crystal display device in which the light source device of the present invention can be built include a desktop or notebook personal computer monitor, a mobile phone, a digital camera, and a portable information terminal. Furthermore, the light source device of the present invention can be applied to a light bulb (lighting fixture) in addition to such a liquid crystal display device. In that case, for example, a streetlight (electric light), a traffic light, lighting of a signboard, an electric bulletin board It can be applied to a light emitting source such as.

In addition to the substrate using “CEM-3” which is a so-called glass composite substrate, for example, so-called “FR-4” having a layer formed by impregnating a glass woven fabric with an epoxy resin is used. It may be a thing.
The mounting board may be one in which the second metal layer is omitted.

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G Light source device 2, 2A, 2F, 2G Mounting substrate (substrate)
21 1st base material layer (base material layer)
22a, 22b Second base material layer (base material layer)
23 1st metal layer (metal layer (front side metal layer))
231 Circuit pattern 232 Heat transfer pattern 24 Second metal layer (back side metal layer)
25 Ventilation part 251,281 Through hole (ventilation hole)
252 Inner metal layer 253 Conductor post (Thermal conductive conductor post)
26 High Density Area 27 Low Density Area 28 Heat Transfer Part 282, 1024 Internal Metal Layer 3 Pressure Difference Generating Means 4 Light Emitting Device 41 Package 411 Recess 42 Light Emitting Diode Element (LED Chip)
43 Translucent resin part 44 External terminal 100 Liquid crystal television 101 Display part (liquid crystal cell)
102 Housing 103 Leg (stand)
104 Polarizing plate 105 Glass substrate 106 Color filter 107 Protective film 108 Liquid crystal part 109 Glass substrate 110 Polarizing plate 111 Front side space 112 Back side space 1022 Through hole 1023 Exhaust port t _total , t ₁ , t ₂ , t ₃ , t ₄ thickness The

Claims (18)

A substrate,
A light-emitting device provided on one surface side of the substrate and including a light-emitting element;
The light source device according to claim 1, wherein the substrate is provided with a plurality of ventilation holes that pass through the substrate in the thickness direction and allow gas to flow therethrough.   The light source device according to claim 1, wherein the plurality of vent holes are provided in a proximal portion proximal to the light emitting device in a surface direction of the substrate.   The light source device according to claim 2, wherein a ratio of an area occupied by the vent hole to an area of the proximal portion of the substrate in a plan view is 0.01% or more and 50% or less. The plurality of vent holes are provided in a proximal portion proximal to the light emitting device and a distal portion distal to the light emitting device in the surface direction of the substrate;
4. The light source device according to claim 1, wherein an arrangement density of the vent holes in the proximal portion is higher than an arrangement density of the vent holes in the distal portion.   5. The light source device according to claim 2, wherein a distance from a center of the light emitting device to an outer peripheral edge of the proximal portion in a surface direction of the substrate is 5 mm or more and 100 mm or less.   The light source device according to any one of claims 1 to 5, wherein each of the vent holes has a circular cross-sectional shape.   The light source device according to claim 6, wherein each of the air holes has a diameter of 0.1 mm to 5 mm.   The light source device according to claim 1, wherein a cross-sectional shape of each of the vent holes is a belt shape.   The light source device according to claim 8, wherein a width of each of the air holes is 0.01 mm or more and 5 mm or less.   8. The L × t is 0.1 or more and 50 or less when the distance between the air holes is L [mm] and the thickness of the substrate is t [mm]. The light source device according to 1.   The light source device according to any one of claims 1 to 10, wherein a gas is circulated from the opposite side of the substrate to the light emitting device side with respect to the air holes.   12. The light source device according to claim 1, further comprising a pressure difference generating unit that generates a pressure difference between a space on one surface side and a space on the other surface side of the substrate.   13. The light source device according to claim 11, wherein each of the vent holes has a portion in which a cross-sectional area gradually increases from the light emitting device side to the opposite side of the substrate. The surface of the substrate opposite to the light emitting device is in contact with the inner peripheral surface of a housing that houses the light emitting device together with the substrate.
The light source device according to claim 1, wherein each of the vent holes penetrates the wall portion of the housing.   The light source device according to claim 1, wherein an inner metal layer made of a metal material is formed on an inner peripheral surface of each of the vent holes.   The light source device according to claim 15, wherein a metal layer made of a metal material is provided on at least one surface of the substrate so as to be in contact with the internal metal layer.   The light source device according to claim 16, wherein a portion of the metal layer that is in contact with the internal metal layer is not electrically connected to the light emitting element.   The light source device according to claim 1, wherein the light source device is used as a backlight of a liquid crystal display device.

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