JP2011159770A - White-light emitting semiconductor device - Google Patents

Abstract

A white semiconductor light emitting device in which light emitting diode elements are integrated at a high density and a large luminous flux can be extracted is provided.
A wiring board;
A plurality of light emitting diode elements mounted directly on the wiring board and having an emission wavelength in the range of 360 nm to 480 nm;
A white semiconductor light-emitting device having a phosphor-containing layer containing a phosphor that emits light when excited by light emitted from the light-emitting diode element,
100 or more of the light emitting diode elements are integrated and mounted on a 10 cm ² region on the wiring board,
The number per unit area of the light emitting diode elements is integrated and mounted at 16 / cm ² or more and 1000 / cm ² or less,
A white semiconductor light-emitting device, wherein the light-emitting diode element mounted in an integrated manner is covered with the phosphor-containing layer.
[Selection] Figure 1

Description

  The present invention relates to a novel white semiconductor light-emitting device that can be used for various lighting devices and the like and can extract a large luminous flux even if it is small.

  A semiconductor light emitting device is widely used as a display device for home appliances, an indoor lighting device, and the like, including a portable terminal. A semiconductor light emitting device is configured, for example, by providing a pair of positive and negative electrodes on a substrate provided with a predetermined wiring pattern, and mounting a light emitting diode element (hereinafter also referred to as “LED chip” as appropriate) on the electrodes. Is done. In addition, for example, by incorporating a phosphor in a sealing part such as a silicone resin and placing it on the LED chip or around the LED chip, the wavelength of light emitted from the LED chip is converted, and different wavelengths are obtained. It is also possible to emit light (for example, Patent Documents 1 to 3).

JP-A-11-168235 JP2003-110144A International Publication No. 2008-018548 Pamphlet

  In recent years, semiconductor light emitting devices are required to extract a large luminous flux, and are required to input high power. In particular, there is a need to provide a white semiconductor light emitting device that is small and can extract a large luminous flux for the purpose of replacing the conventional lighting fixture. However, when LED chips are densely integrated for the purpose of downsizing and a phosphor-containing layer containing a phosphor is laminated on the LED chip, it is difficult to obtain a large luminous flux from the entire light emitting device. there were.

  Conventionally, it has been considered that the above-mentioned problem is caused by the fact that the LED chips are integrated at a high density, whereby the heat generated by the LED chips is easily trapped in the semiconductor light emitting device, and the light emission efficiency of the LED chips is reduced. .

As a result of studies by the present inventors, when the distance between the light-emitting diode elements to be integrated and mounted is changed and covered with a transparent sealant, the radiation flux emitted from the entire light-emitting diode elements that are integrated and mounted is large. I found no change. That is, it has been found that the above problem is likely to occur when a phosphor-containing layer is laminated on a light emitting diode element. As a result of further diligent research conducted by the present inventors, the structure of the white semiconductor light-emitting device is a chip-on-board type, and a predetermined number or more of light-emitting diode elements are formed at a predetermined density in a predetermined region. It was found that a large luminous flux can be taken out from a white semiconductor light emitting device by integrating mounting and covering with a phosphor-containing layer, and the present invention has been completed.
The gist of the present invention is as follows.

(1) A wiring board, a plurality of light emitting diode elements mounted directly on the wiring board and having an emission wavelength in the range of 360 nm to 480 nm, and a phosphor that emits light when excited by light emitted from the light emitting diode elements A white semiconductor light emitting device having a phosphor-containing layer containing 100 or more of the light emitting diode elements integratedly mounted in a 10 cm ² region on the wiring substrate, and the light emitting diode element per unit area The white semiconductor is characterized in that the number of LEDs is integrated and mounted at 16 / cm ² or more and 1000 / cm ² or less, and the light-emitting diode elements that are integrated and mounted are covered with the phosphor-containing layer. Light emitting device.

(2) The white semiconductor light-emitting device according to (1), wherein the light-emitting diode element is flip-mounted.
(3) The gap between adjacent light-emitting diode elements of the light-emitting diode elements mounted in an integrated manner is 0.05 mm or more and 2.0 mm or less, according to (1) or (2) White semiconductor light emitting device.
(4) The white semiconductor light-emitting device according to any one of (1) to (3), wherein the light-emitting diode elements mounted in an integrated manner are electrically connected in series and parallel.
(5) The white semiconductor light-emitting device according to any one of (1) to (4), wherein the concentration of the phosphor in the phosphor-containing layer is 5% by weight or more and 90% by weight or less.
(6) The white semiconductor light-emitting device according to any one of (1) to (5), wherein a distance between centers of adjacent light-emitting diode elements is 0.1 mm or more and 2.0 mm or less.
(7) The white semiconductor light-emitting device according to any one of (1) to (6), wherein the area of each light-emitting diode element is 20000 μm ² or more and 360000 μm ² or less.

(8) The white semiconductor light-emitting device according to any one of (1) to (7), wherein the wiring board is a heat dissipation board.
(9) The phosphor-containing layer is excited by light emitted from the light-emitting diode element, and excited by light emitted from the light-emitting diode element and a layer containing a red phosphor that emits red light. A layer containing a green phosphor that emits green light, and a layer containing a blue phosphor that is excited by the light emitted from the light emitting diode element to emit blue light, from the light emitting diode element side. The white semiconductor light-emitting device according to any one of (1) to (8), which is stacked in this order.
(10) An illumination device comprising the white semiconductor light-emitting device according to any one of (1) to (9).

  According to the present invention, since the light emitting diode elements are integrated and mounted at a predetermined density in a certain area at a predetermined density, the phosphors in the phosphor-containing layer can be excited efficiently, and the light emitting diode elements A large luminous flux can be obtained from the region where the components are integrated and mounted. Accordingly, it is possible to provide a white semiconductor light emitting device that can extract a large luminous flux even when it is a small device.

It is the schematic which shows an example of the white semiconductor light-emitting device of this invention, (a) is a schematic plan view when it observes from the light extraction surface side, (b) is (alpha) -alpha part in (a). It is a schematic sectional drawing. It is a schematic sectional drawing which shows the other example of the white semiconductor light-emitting device of this invention. It is a schematic sectional drawing which shows the other example of the white semiconductor light-emitting device of this invention. It is a schematic plan view showing an example of the wiring board used for the white semiconductor light-emitting device of this invention. It is a schematic plan view showing the other example of the wiring board used for the white semiconductor light-emitting device of this invention. It is a schematic plan view showing the other example of the wiring board used for the white semiconductor light-emitting device of this invention. It is a schematic plan view showing the other example of the wiring board used for the white semiconductor light-emitting device of this invention. It is a graph which shows the relationship between a drive current amount and a total radiant flux about the white semiconductor light-emitting device of Examples 1-4. It is a graph which shows the relationship between a drive current amount and a total luminous flux about the white semiconductor light-emitting device of Examples 1-4.

  Hereinafter, although an embodiment of the present invention is described in detail, the present invention is not limited to the following contents, and can be arbitrarily changed and implemented without departing from the gist thereof.

  A schematic diagram of an example of the white semiconductor light-emitting device of the present invention is shown in FIG. FIG. 1A is a schematic plan view of the white semiconductor light emitting device observed from the light extraction surface side, and FIG. 1B is a schematic cross-sectional view of the α-α portion in FIG. . However, these drawings are schematically shown for explaining the white semiconductor light emitting device of the present invention, and do not accurately show the scale of each member.

  As shown in FIG. 1, a white semiconductor light emitting device 10 according to the present invention includes a wiring board 1, a plurality of light emitting diode elements 2 arranged on the wiring board 1, and a phosphor-containing layer 3 containing a phosphor. In the present invention, the light emitting diode elements 2 are integratedly mounted in a predetermined range in a predetermined number or more, and the number per unit area is in the predetermined range, and further integratedly mounted. It is characterized in that the light emitting diode element 2 is covered with the phosphor-containing layer 3.

In the present invention, space saving is realized by flip-chip mounting, preferably in a so-called chip-on-board type, in which the wiring board 1 which is a heat dissipation board and the light-emitting diode element 2 are directly connected. Yes. That is, a predetermined number or more of light emitting diode elements 2 can be integrated per unit area. Moreover, by setting it as such an integration density, the fluorescent substance in the fluorescent substance containing layer 3 can be excited efficiently. The reason why a large luminous flux can be obtained from the white semiconductor light emitting device 10 by setting the predetermined density is as follows. Sufficient heat dissipation is possible even at a predetermined density, and a decrease in light emission efficiency of the light emitting diode element can be suppressed. Further, since there is a certain distance between the adjacent light emitting diode elements 2, the phosphor-containing layer 3 is likely to enter the gap, and the excitation efficiency of the phosphor is improved. Further, light emitted from the adjacent light emitting diode element 2 can be reduced from being reabsorbed by the light emitting diode element 2, and the light emitted from the light emitting diode element 2 is absorbed by the phosphor-containing layer 3 to convert the wavelength. Alternatively, since it is scattered in the phosphor-containing layer 3, it is considered that wavelength conversion by the phosphor-containing layer 3 can be efficiently advanced. Further, a layer containing a red phosphor that emits red light that is excited by the light emitted from the light emitting diode element 2 and the green light that is excited by the light emitted from the light emitting diode element 2 are emitted. A green phosphor containing layer and a layer containing a blue phosphor excited by light emitted from the light emitting diode element 2 to emit blue light are laminated in this order from the light emitting diode element 2 side. As a result, cascade excitation can be reduced, and wavelength conversion by the phosphor-containing layer 3 can be efficiently advanced.
Hereinafter, each structure of the white semiconductor light-emitting device of this invention is demonstrated.

1. Light emitting diode element (emission wavelength)
As the light emitting diode element, a light having a peak wavelength of 300 nm or more and 480 nm or less, that is, a light emitting from the near ultraviolet wavelength region to the blue region is used. Specifically, an ultraviolet light emitting diode element that emits ultraviolet light (emission peak wavelength: 300 to 400 nm), a purple light emitting diode element that emits violet light (emission peak wavelength: 400 to 440 nm), and a blue light emitting diode element that emits blue light (light emission). For example, a peak wavelength of 440 nm to 480 nm can be applied. The light-emitting diode element is capable of emitting light that can excite a phosphor or a fluorescent component (hereinafter also simply referred to as “phosphor”) contained in a phosphor-containing layer described later. There are no particular restrictions on the type. The peak wavelength of light emitted from the light-emitting diode element is more preferably 370 nm or more, and further preferably 380 nm or more. More preferably, it is 420 nm or less, More preferably, it is 415 nm or less.

(Number per unit area)
The number of light emitting diode elements per unit area in the white semiconductor light emitting device is usually 16 / cm ² or more, preferably 20 / cm ² or more, more preferably 25 / cm ² or more. Moreover, it is 1000 pieces / cm < ² > or less normally, Preferably it is 625 pieces / cm < ² > or less, More preferably, it is 400 pieces / cm < ² > or less, More preferably, it is 256 pieces / cm < ² > or less. By setting the number per unit area to be equal to or less than the upper limit value, a large luminous flux can be easily obtained from the white semiconductor light emitting device, and by setting the number per unit area to be equal to or greater than the lower limit value, the white semiconductor light emitting device can be miniaturized. The number per unit area is the number of light emitting diode elements included per unit area when the surface of the white semiconductor light emitting device projected from the light extraction surface side is observed.

In the white semiconductor light emitting device, it is preferable that 49 or more light emitting diode elements are integrated in a region of 10 cm ² or more, more preferably 64 or more, further preferably 100 or more, and particularly preferably 121. That's it. Moreover, it is 900 or less normally, Preferably it is 625 or less, More preferably, it is 400 or less. As a result, a large luminous flux can be extracted from the white semiconductor light emitting device. The plurality of light emitting diode elements may be randomly arranged in the white semiconductor light emitting device, but it is usually preferable to regularly arrange them from the viewpoint of high integration and control of the light emitting diode elements. In particular, as shown in FIG. 1A, the light emitting diode elements 2 are preferably arranged in a matrix.

  A gap between adjacent light emitting diode elements (for example, a distance represented by t and t ′ in FIG. 1A; a distance obtained by subtracting the length of one side of the light emitting diode element from the distance between the centers of the light emitting diode elements) is, for example, When the shape of the light emitting diode element when the surface projected from the light extraction surface side of the white semiconductor light emitting device is observed is a rectangle, and the length of the long side of the rectangle is 350 μm, the gap is 0.01 mm or more. More preferably, it is 0.03 mm or more, More preferably, it is 0.05 mm or more, Most preferably, it is 0.15 mm or more. Moreover, it is 2.0 mm or less normally, it is preferable that it is 0.4 mm or less, More preferably, it is 0.3 mm or less, More preferably, it is 0.2 mm or less. In the case where a step is provided on the wiring board, the distance between the light emitting diode elements is a three-dimensional distance, which is a value measured along the shape of the wiring board.

  The gap is appropriately selected depending on the shape of the light emitting diode element when the surface of the white semiconductor light emitting device projected from the light extraction surface side is observed. For example, when the shape of the light emitting diode element is rectangular, the gap is The length of the long side of the rectangle is preferably 3% or more, more preferably 10% or more, and still more preferably 20% or more. Further, it is usually 500% or less, preferably 250% or less, and more preferably 200% or less. By having a gap within the above range, a large luminous flux can be obtained from the white semiconductor light emitting device.

  Furthermore, the distance between the centers of adjacent light emitting diode elements, that is, the distance between the adjacent light emitting diode elements from the center of each light emitting diode element is preferably 0.1 mm or more, more preferably 0.2 mm or more, Preferably it is 0.3 mm or more, Most preferably, it is 0.5 mm or more. Moreover, it is 2.0 mm or less normally, Preferably it is 1.0 mm or less, More preferably, it is 0.8 mm or less. By setting the lower limit value or more, a large luminous flux can be easily obtained from the white semiconductor light emitting device. Moreover, by setting it as an upper limit value or less, it becomes possible to integrate light emitting diode elements at high density. The central portion of the light emitting diode element means a central portion of the shape in which each light emitting diode element is projected from the light extraction surface side of the white semiconductor light emitting device. For example, the projected shape is also a rectangular shape, for example. Is the intersection of diagonal lines of the rectangle. Further, the distance between the centers of adjacent light emitting diode elements refers to a length that minimizes the length between the central portions of the adjacent light emitting diode elements.

  The area occupation ratio of the light emitting diode elements in the integrated mounting region is preferably 2% or more, more preferably 5% or more, and further preferably 10% or more. Moreover, 90% or less is preferable, More preferably, it is 80% or less, More preferably, it is 70% or less. By setting the occupied area, it is easy to efficiently obtain a large luminous flux from the white semiconductor light emitting device. The integrated mounting area refers to a series of areas in which light emitting diode elements are integratedly mounted, which is covered with a phosphor-containing layer when the white semiconductor light emitting device is observed from the light extraction surface side. . The area occupancy is a value obtained by dividing the total area of the light emitting diode elements present in the integrated mounting region by the area of the integrated mounting region when the white semiconductor light emitting device is observed from the light extraction surface side.

  Further, the total perimeter of each light emitting diode element present in the integrated mounting region is preferably 30 mm or more, more preferably 50 mm or more, and further preferably 100 mm or more. Moreover, 1000 mm or less is preferable normally, More preferably, it is 500 mm or less, More preferably, it is 400 mm or less. By setting it as the above range, it is easy to efficiently obtain a large luminous flux from the white semiconductor light emitting device. The peripheral length of each light emitting diode element means the peripheral length of each light emitting diode element when the white semiconductor light emitting device is observed from the light extraction surface side.

(shape)
The shape of the light-emitting diode element (the shape when the white semiconductor light-emitting device is projected from the light extraction surface side) may be any shape as long as the effects and objects of the present invention are not impaired, for example, a rectangular shape or a polygonal shape. However, from the viewpoint of ease of processing of the light emitting diode element substrate, it is usually in a rectangular shape or a shape close thereto. In addition, the shape of all the light emitting diode elements arrange | positioned in a white semiconductor light-emitting device may be the same, and may differ.

The area of each light-emitting diode element, preferably 20000Myuemu ² or more, more preferably 40000Myuemu ² or more, further preferably 80000Myuemu ² or more. Moreover, it is usually 360,000 μm ² or less, preferably 250,000 μm ² or less, more preferably 200000 μm ² or less. By setting the lower limit value or more, light can be efficiently emitted by flip mounting, and by setting the lower limit value or less, the light emitting diode elements can be arranged in the target number per unit area. Note that the area of the light emitting diode element in the present invention means an area of a shape obtained by projecting the light emitting diode element from the light extraction surface side of the white semiconductor light emitting device.

  In addition, when the light emitting diode element is rectangular (square or rectangular), the length of one side is usually 100 μm or more, preferably 200 μm or more, more preferably 250 μm or more, and still more preferably. Is 300 μm or more. Moreover, it is preferable that it is 600 micrometers or less, More preferably, it is 500 micrometers or less, More preferably, it is 400 micrometers or less. By setting it within the above range, the light emitting diode elements can be arranged in the number per unit area per unit area per target unit area.

  Usually, a light-emitting diode element is manufactured by cutting a light-emitting diode element substrate or the like to a desired size, but if the shape of the cut surface is uneven, the light-emitting diode elements can be arranged close to each other. It can be difficult. Therefore, the side surface of the light emitting diode element is preferably highly planar. As a method for increasing the planarity of the side surface of the light-emitting diode element, a method of cutting the light-emitting diode element substrate or the like with a laser scriber or the like can be given.

(Concrete example)
Specifically, a light emitting diode (hereinafter abbreviated as “LED”) or a semiconductor laser diode (hereinafter abbreviated as “LD”) can be used as the light emitting diode element.
Among them, as the light emitting diode element, a GaN LED or LD in which a GaN compound semiconductor layer is formed on a light emitting diode element substrate is preferable. This is because GaN-based LEDs and LDs have significantly larger light emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are combined with phosphors in the phosphor-containing layer described later. This is because very bright light emission can be obtained with low power. For example, for a current load of 20 mA, GaN-based LEDs and LDs usually have a light emission intensity 100 times or more that of SiC-based. GaN-based LEDs and LDs preferably have an Al _X Ga _Y N light emitting layer, a GaN light emitting layer, or an In _X Ga _Y N light emitting layer. Among the GaN-based LEDs, those having an In _X Ga _Y N light emitting layer are particularly preferable because the light emission intensity is very strong. Of the GaN-based LDs, those having a multiple quantum well structure of an In _X Ga _Y N layer and a GaN layer are particularly preferred because the emission intensity is very strong.

  In the above, the value of X + Y is usually a value in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics.

As a GaN-based LED, usually, the light emitting layer, the p layer, the n layer, the electrode, and the substrate for the light emitting diode element can be used as basic components, and the light emitting layer is composed of n-type and p-type Al _X. Those having a heterostructure sandwiched between Ga _Y N layers, GaN layers, In _X Ga _Y N layers, etc. have high luminous efficiency, and those having a hetero structure in a quantum well structure emit light. Higher efficiency and more preferable. These stacking methods can be the same as the general method for forming a light-emitting diode element.

  The light-emitting diode element used in the present invention has a power consumption during operation of usually 5 W or less, preferably 4 W or less, more preferably 3 W or less, usually 0.060 W or more, preferably 0.065 W or more. More preferably, it is 0.070 W or more. If the amount of power during operation is too small, the light output generally tends to be low and disadvantageous in terms of cost, and if it is too large, it is difficult to dissipate the phosphor, and the sealing agent contained in the phosphor and the phosphor-containing layer, There is a possibility that a light emitting diode element or the like is thermally deteriorated or a failure due to electrode migration is induced. Moreover, the lifetime of the obtained white semiconductor light-emitting device may become short by these.

  In the white semiconductor light emitting device of the present invention, the light emitting diode element is directly mounted on a wiring board. The method for connecting the light emitting diode element and the wiring board described later is not particularly limited. For example, when the light emitting diode element substrate is made of a conductive material such as SiC or GaN, the number of electrodes on the upper surface is one (for example, Single wire bonding) configuration. When the light emitting diode element substrate is made of a low refractive index insulating material such as sapphire, for example, the light emitting layer is the upper surface and the light emitting diode element substrate is the lower surface. , N2 electrodes are provided and bonded to the substrate with a gold wire or the like (double wire bonding), or the light emitting layer is the bottom surface and the light emitting diode element substrate side is the top surface and is bonded to a wiring substrate described later (flip chip mounting) ) And the like.

  In the present invention, among the above configurations, a configuration in which the light-emitting diode element is directly flip-chip mounted on the wiring board is preferable. Thereby, space saving can be achieved easily.

  Further, the ratio of the light emitted toward the light emitting surface and the side surface of the light emitting diode element may be adjusted according to the purpose of use of the light emitting diode element. These can be controlled by the cut shape of the light emitting surface or side surface of the light emitting diode element. For example, by cutting the side surface of the light emitting diode element into a shape that suppresses total reflection of light emitted from the light emitting layer, it is possible to increase the ratio of light emitted toward the side surface and improve light extraction efficiency. .

2. Wiring Substrate The wiring substrate in the white semiconductor light emitting device of the present invention is not particularly limited as long as it has a wiring pattern. For example, a printed wiring made of metal is applied on an insulating substrate or film. In addition, the surface of the insulating substrate or the side opposite to the wiring of the film can be a structure in which it is bonded to a metal plate.

  4 to 7 are schematic plan views showing examples of the wiring board. However, the present invention is not limited to these. 4 to 7 show examples in which a wiring pattern 10 is provided by plating on an insulating substrate (not shown) such as aluminum nitride. Moreover, the unit of the dimension shown in FIGS. 4-7 is mm. 4 to 7, 11 × 11 light emitting diode elements are mounted, and the mounting position of the light emitting diode elements is, for example, a quadrilateral of the wiring pattern shown by a in FIG. 4. Are mounted so as to straddle a quadrilateral pattern (convex portion) formed at an intermediate position of one side (in the figure, a indicates only three places, but the same applies to other patterns). Since one side of the quadrilateral has a quadrilateral pattern (convex portion), the position of the light-emitting diode element to be flip-mounted can be easily recognized. In addition, it is difficult in terms of the accuracy of the wiring pattern to shorten the interval between the electrodes as one side of the quadrilateral. However, the interval between the electrodes can be made shorter than the interval between the quadrilaterals by providing the convex portions. 4 shows the case where the distance between the centers of adjacent light emitting diode elements is 2.0 mm, FIG. 5 shows the case of 1.5 mm, FIG. 6 shows the case of 1.0 mm, and FIG. 7 shows the case of 0.6 mm. is there. Although not shown in the wiring boards of FIGS. 4 to 7, parallel wiring or the like is also possible inside.

(Insulating substrate)
Examples of the insulating substrate or film include a ceramic substrate, a resin substrate, a glass epoxy substrate, and a composite resin substrate containing a filler in the resin. In particular, in order to efficiently dissipate heat generated by the light emitting diode element, it is preferable that the wiring board is a heat dissipation board. As the heat dissipation substrate, for example, a ceramic substrate such as alumina or aluminum nitride, a composite resin substrate containing a filler having high thermal conductivity, or the like can be suitably used.

  The shape of the insulating substrate is not limited to a flat plate shape, and various shapes can be adopted according to the type and application of the white semiconductor light emitting device. For example, a step may be provided on an insulating substrate. Specifically, there is a substrate in which the region where each light emitting diode element is mounted is a concave portion and the region between each light emitting diode element is a convex portion. In this case, light is retransmitted between adjacent light emitting diode elements. It can be assumed that there is no absorption, and a larger luminous flux can be obtained. As a method of providing a step on the substrate, a general method can be used. For example, the step can be provided by stacking the substrates.

  A reflective member for reflecting the light emitted from the light emitting diode element may be formed on the insulating substrate. The reflecting member is not particularly limited in its formation position and shape as long as it does not impair the object and effect of the present invention. The reflective member may be, for example, a layer made of a metal printed at the same time as a wiring pattern described later, or a metal such as ceramic, silver, or aluminum, or Kovar, an alloy such as silver-platinum or silver-palladium, or white. It may be a layer made of a solder resist or the like. These may be used in combination.

  Furthermore, a heat radiating member for radiating heat generated from the light emitting diode element may be formed on the insulating substrate. The heat radiating member may be, for example, a layer made of a metal such as copper or aluminum, or may be a resin in which a high heat radiating metal or a ceramic filler is dispersed at a high density.

(Wiring pattern)
The wiring pattern is not particularly limited and may be appropriately selected according to the type and purpose of the white semiconductor light emitting device, and may be, for example, a pad pattern, a power feeding land pattern, and a pattern connecting them.

  The power feeding land pattern is usually formed outside the integrated mounting region, that is, a region not covered with the phosphor-containing layer, and is electrically connected to an external power source and used to receive power from the external power source. A plurality of pad patterns are provided corresponding to the plurality of light emitting diode elements described above, and are connected to the electrodes on the light emitting diode element side. In addition, the power feeding land pattern and the pad pattern are connected via a conductor pattern. The shape of these patterns is appropriately selected according to the purpose, and may be, for example, a multilayer wiring or the like.

Here, as described above, when the light emitting diode elements are arranged in a matrix, it is possible to use a pattern in series and parallel (connected in series and parallel) to control the driving voltage and the light emitting diode elements. From the aspect, it is preferable. Examples of such a method include a method in which the row directions of light emitting diode elements arranged in a matrix are connected in series and the column directions are connected in parallel.
In addition, since the voltage at the time of connecting in series is a value obtained by multiplying the Vf value of each light emitting diode by the number of series, the light emitting diode elements should be connected so that the voltage is usually less than 300V, preferably less than 250V. Is preferred.

  In the present invention, it is preferable that the material used for the wiring pattern has a high reflectance. Specifically, the reflectance of light having a wavelength of 400 nm is preferably 70% or more, more preferably 75% or more, and further preferably 80% or more. Thereby, the brightness | luminance of a white semiconductor light-emitting device can be made favorable.

  The method of measuring the reflectance is preferably a method that uses an integrating sphere or the like to include both regular reflection light and diffuse reflection light. For example, the reflectance can be measured using a spectrocolorimeter CM2600d manufactured by Konica Minolta Sensing Co., Ltd. I can do it.

  Moreover, as a material used for a wiring pattern, gold | metal | money, silver, copper, aluminum etc. are normally mentioned, Among these, gold | metal | money, silver, and copper are preferable from the surface that the brightness | luminance improvement and the maintenance effect of a brightness | luminance are easy to be acquired. These may use only 1 type and may use it in combination of 2 or more type.

3. Phosphor-containing layer The phosphor-containing layer of the present invention covers the wiring board and the light-emitting diode element described above, and includes a phosphor that emits light when excited by light emitted from the light-emitting diode element. There is no particular limitation on the type. Usually, a sealing member for sealing a light emitting diode element and a wiring board, and an inorganic or organic phosphor that absorbs light emitted from the light emitting diode element and converts the wavelength to an arbitrary wavelength are included. be able to. Furthermore, the phosphor-containing layer may contain a thixotropic agent, a refractive index adjusting agent, a light diffusing agent, and the like as necessary.

  When the emission wavelength of the light emitting diode element is ultraviolet or purple, light of three primary colors of RGB (red, green and blue) is generated by using a red phosphor, a green phosphor and a blue phosphor as a phosphor, or , BY (blue and yellow), RG (red and green), and the like, white light can be obtained by generating light having a complementary color relationship. When the emission wavelength of the light emitting diode element is blue, yellow (Y) light is generated by the yellow phosphor, or RG (red and green) light is generated by the red phosphor and the green phosphor (purpose) Depending on the above, Y (yellow) light may be further generated by the yellow phosphor), and white light is obtained by mixing with the blue light emission of the light emitting diode element.

  The film thickness of the phosphor-containing layer is usually 20 μm or more, preferably 50 μm or more, and more preferably 75 μm or more. Moreover, it is 3000 micrometers or less normally, Preferably it is 2000 micrometers or less, More preferably, it is 1500 micrometers or less. Thereby, absorption of excitation light and reabsorption of phosphors can be prevented. In the case where the phosphor-containing layer has a layer structure in which a plurality of layers are laminated, it is preferable that each of these film thicknesses is in the above range.

  The shape of the phosphor-containing layer is not particularly limited as long as the wiring board and the light-emitting diode element can be sealed. Particularly, for example, as shown in FIG. 3, the gap between adjacent light-emitting diode elements 2 is not limited. It is preferable that the phosphor-containing layer (3R, 3G, and 3B) is in a shape.

  Further, the layer structure of the phosphor-containing layer is not particularly limited as long as the object and effect of the present invention are not impaired. For example, as an embodiment of the phosphor-containing layer, at least as shown in FIG. A single layer 3 containing one kind, preferably a plurality of kinds of phosphors can be formed. These phosphors are contained in the phosphor-containing layer uniformly or with a continuous concentration distribution.

  The phosphor-containing layer contains a plurality of types of phosphors having different emission colors (emission wavelength peaks), and in particular, the phosphors are unstable with respect to electricity, heat, and light under lighting use conditions. When the phosphor is included, a layer structure in which only the specific phosphor is separated from the light emitting diode element and another stable phosphor is disposed in the vicinity of the light emitting diode element may be employed.

  As another embodiment of the phosphor-containing layer, for example, as shown in FIGS. 2 and 3, the phosphor-containing layer contains a red phosphor that is excited by light emitted from the light-emitting diode element 2 and emits red light. Layer 3R (hereinafter also referred to as “red phosphor-containing layer” as appropriate) and layer 3G (hereinafter, referred to as “red phosphor containing layer”) containing green phosphor that is excited by light emitted from the light emitting diode element 2 and emits green light. And a layer 3B containing a blue phosphor that is excited by light emitted from the light emitting diode element 2 and emits blue light (hereinafter referred to as “blue phosphor” as appropriate). It is also referred to as a “containing layer”). The order of lamination of the above-described color phosphor-containing layers is not particularly limited as long as the object and effect of the present invention are not impaired, but in particular, from the light emitting diode element 2 side, the red phosphor-containing layer 3R, the green phosphor-containing layer 3G, And the blue phosphor-containing layer 3B are particularly preferably laminated in this order from the viewpoint of luminous efficiency and color rendering properties of the luminescent color of the white semiconductor light emitting device. When the phosphor-containing layer whose wavelength after conversion by the phosphor is a short wavelength is arranged on the light emitting diode element side, the light of the wavelength after the conversion is used to excite the phosphor of the phosphor-containing layer on the surface side. May contribute.

  In the present invention, the phosphor is substantially not contained between the phosphor-containing layer and the light-emitting diode element, and is emitted from the light-emitting diode element without changing the wavelength of light from the light-emitting diode element. A light guide layer or the like that guides light to the phosphor-containing layer may be formed. By interposing a light guide layer between the light emitting diode element and the phosphor containing layer, the phosphor is separated from the light emitting diode element as compared with a white semiconductor light emitting device having a layer structure in which the light emitting diode element is directly covered with the phosphor containing layer. Can be arranged. As a result, deterioration of the phosphor due to ultraviolet rays can be reduced, and a white semiconductor light emitting device having a stable function for a long time can be obtained. Further, since the light guide layer substantially does not contain a phosphor, even if the temperature of the light guide layer rises due to heat generation of the light emitting diode element, the influence on the phosphor is small. Therefore, deterioration of the phosphor due to temperature can also be suppressed. Specifically, the light guide layer may be a layer containing a sealing member to be described later. The light guide layer may contain a thixotropic agent, a refractive index adjusting agent, a light diffusing agent, or the like as necessary.

(Sealing member)
The sealing member used for the phosphor-containing layer is not particularly limited, and a curable material that can be molded over the wiring board and the light-emitting diode element can be usually used. The curable material is a fluid material that is cured by performing some kind of curing treatment. Here, the fluid state means, for example, a liquid state or a gel state.

As the curable material, any of an inorganic material, an organic material, and a mixture of both can be used.
As the inorganic material, for example, a solution obtained by hydrolytic polymerization of a solution containing a metal alkoxide, a ceramic precursor polymer or a metal alkoxide by a sol-gel method, or a combination thereof is solidified (for example, a siloxane bond). Inorganic materials having

  On the other hand, examples of the organic material include a thermosetting resin and a photocurable resin. Specific examples include (meth) acrylic resins such as poly (meth) acrylic acid methyl; styrene resins such as polystyrene and styrene-acrylonitrile copolymers; polycarbonate resins; polyester resins; phenoxy resins; butyral resins; Cellulose resins such as cellulose acetate and cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins and the like.

  Conventionally, an epoxy resin has been generally used as a phosphor dispersion material for a white semiconductor light emitting device. However, in the present invention, there is little deterioration with respect to light emission from the light emitting diode element, and heat resistance is also improved. It is preferred to use an excellent silicon-containing compound.

  A silicon-containing compound refers to a compound having a silicon atom in the molecule, organic materials such as polyorganosiloxane (silicone-based materials), inorganic materials such as silicon oxide, silicon nitride, and silicon oxynitride, and borosilicates and phosphosilicates. Examples thereof include glass materials such as salts and alkali silicates. Among these, silicone materials are preferable from the viewpoint of transparency, adhesiveness, ease of handling, and the point that the cured product has stress relaxation force. Regarding silicone resins for semiconductor light emitting devices, for example, use as a sealant in JP-A-10-228249, JP-A-2927279, JP-A-2001-36147, etc., and JP-A 2000-123981 to wavelength adjustment coating. The use of is being tried.

  From the aspect of light extraction efficiency, the resin contained in the phosphor-containing layer preferably has a light transmittance of 80% or more, more preferably 85% or more at an emission wavelength of 350 nm to 500 nm at a film thickness of 1 mm. It is usually 98% or less.

  As long as the effect of the present invention is not significantly impaired, the sealing member can be used by further mixing other components with the above-described inorganic material and / or organic material. In addition, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and ratios.

(Phosphor)
Examples of the phosphor used in the white semiconductor light-emitting device of the present invention include the following red, yellow, green, and blue phosphors excited by light from the light-emitting diode element, that is, near-ultraviolet light. One or more selected can be used alone, or two or more can be used in any combination and in any ratio.

There is no particular limitation on the composition of the phosphor, but a metal oxide represented by Y ₂ O ₃ , YVO ₄ , Zn ₂ SiO ₄ , Y ₃ Al ₅ O ₁₂ , Sr ₂ SiO _4, etc., which becomes a base crystal, Metal nitrides typified by (Ca, Sr) AlSiN _{3 and the} like, phosphates typified by Ca ₅ (PO ₄ ) ₃ Cl and the like, sulfides typified by ZnS, SrS, CaS and the like, Y ₂ O ₂ Rare earth metal ions such as Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Ag, Cu, and the like such as oxysulfides represented by S, La ₂ O ₂ S, etc. , Au, Al, Mn, Sb, and other metal ions may be combined as activators or coactivators. Table 1 shows specific examples of preferred crystal matrixes.

In the illustration of the present invention, phosphors that are different only in part of the structure are omitted as appropriate. For example, “Y ₂ SiO ₅ : Ce ³⁺ ”, “Y ₂ SiO ₅ : Tb ³⁺ ” and “Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ ” are changed to “Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ ”, “ “La ₂ O ₂ S: Eu”, “Y ₂ O ₂ S: Eu” and “(La, Y) ₂ O ₂ S: Eu” are collectively shown as “(La, Y) ₂ O ₂ S: Eu”. ing. Omitted parts are separated by commas (,).

  However, the parent crystal and the activator element or coactivator element are not particularly limited in element composition, and can be partially replaced with elements of the same family, and the obtained phosphor absorbs near ultraviolet light. Any material that emits visible light can be used.

  Specifically, the following phosphors can be used, but these are merely examples, and phosphors that can be used in the present invention are not limited to these. In the following examples, as described above, phosphors that differ only in part of the structure are omitted as appropriate.

[Orange to red phosphor]
Any orange or red phosphor can be used as long as the effects of the present invention are not significantly impaired.
At this time, the emission peak wavelength of the orange to red phosphor, which is the same color combination phosphor, is usually 570 nm or more, preferably 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, preferably 700 nm or less, more preferably 680 nm. It is preferable to be in the following wavelength range.

Among these, as red phosphors, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr , Ba) AlSi (N, O) ₃ : Eu, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu, (La, Y) ₂ O ₂ S: Eu, Eu (dibenzoylmethane) ) ₃ · 1,10-phenanthroline complexes of β- diketone Eu complex, a carboxylic acid Eu _complex, K 2 _SiF 6: Mn is _{preferred, (Ca, Sr, Ba)} 2 Si 5 (N, O) 8: Eu, (Sr, Ca) AlSi (N, O): Eu, (La, Y) ₂ O ₂ S: Eu, and K ₂ SiF ₆ : Mn are more preferable.

As the orange phosphor, (Sr, Ba) ₃ SiO ₅ : Eu, (Sr, Ba) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, ( Ca, Sr, Ba) AlSi (N, O) ₃ : Ce is preferred.

[Blue phosphor]
When using blue fluorescent substance, the said blue fluorescent substance can use arbitrary things, unless the effect of this invention is impaired remarkably. At this time, the emission peak wavelength of the blue phosphor is usually 420 nm or more, preferably 430 nm or more, more preferably 440 nm or more, and usually less than 500 nm, preferably 490 nm or less, more preferably 480 nm or less, more preferably 470 nm or less, It is particularly preferable that the wavelength range is 460 nm or less.

Among these, as the blue phosphor, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, (Ba , Ca, Mg, Sr) ₂ SiO ₄ : Eu, (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : Eu are preferred, and (Ba, Sr) MgAl ₁₀ O ₁₇ : Eu, (Ca, Sr, Ba) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, Ba ₃ MgSi ₂ O ₈ : Eu are more preferable, and Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, BaMgAl ₁₀ O ₁₇ : Eu is particularly preferable.

[Green phosphor]
When the green phosphor is used, any green phosphor can be used as long as the effect of the present invention is not significantly impaired. At this time, the emission peak wavelength of the green phosphor is preferably in the range of usually 500 nm or more, particularly 510 nm or more, more preferably 515 nm or more, and usually less than 550 nm, especially 542 nm or less, more preferably 535 nm or less. If this emission peak wavelength is too short, it tends to be bluish, while if it is too long, it tends to be yellowish, and the characteristics as green light may deteriorate.

Among these, as the green phosphor, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, CaSc ₂ O ₄ : Ce, Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce, (Sr, Ba) ₂ SiO ₄ : Eu, (Si, Al) ₆ (O, N) ₈ : Eu (β-sialon), (Ba, Sr) ₃ Si ₆ O ₁₂ : N ₂ : Eu, SrGa ₂ S ₄ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Mn is preferred.

[Preferred combinations]
When the white semiconductor light-emitting device of the present invention is used in an illumination device, (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu is used as a red phosphor, and (Ca, Sr, Ba) MgAl ₁₀ is used as a blue phosphor. O ₁₇ : Eu, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, CaSc ₂ O ₄ : Ce, Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce, (Sr, Ba) ₂ as a green phosphor A combination of SiO ₄ : Eu, (Si, Al) ₆ (O, N) ₈ : Eu (β-sialon) or (Ba, Sr) ₃ Si ₆ O ₁₂ : N ₂ : Eu is preferably used.

When the white semiconductor light emitting device of the present invention is used for an image display device, (Ca, Sr, Ba) AlSiN ₃ : Eu is used as a red phosphor, and (Sr, Ca, Ba, Mg) ₁₀ ( PO ₄ ) ₆ (Cl, F) ₂ : Eu, green phosphor (Sr, Ba) ₂ SiO ₄ : Eu, (Si, Al) ₆ (O, N) ₈ : Eu (β-sialon), (Ba , Sr) ₃ Si ₆ O ₁₂ : N ₂ : Eu, SrGa ₂ S ₄ : Eu, and BaMgAl ₁₀ O ₁₇ : Eu, Mn are preferably used in combination.
[Other phosphors]
As the phosphor, it is possible to contain a phosphor other than those described above. For example, the phosphor-containing layer itself can be formed of a fluorescent resin in which an ionic fluorescent material or an organic / inorganic fluorescent component is dissolved and dispersed uniformly and transparently.

[Particle size of phosphor]
The particle size of the phosphor in the phosphor-containing layer is preferably a particle size at which light from the light emitting diode element is sufficiently scattered.
The particle size of the phosphor is not particularly limited, but is the median particle size (D ₅₀ ) and is usually 0.1 μm or more, preferably 2 μm or more, more preferably 5 μm or more. Moreover, it is 100 micrometers or less normally, Preferably it is 50 micrometers or less, More preferably, it is 20 micrometers or less. When the median particle diameter (D ₅₀ ) of the phosphor is in the above range, the light emitted from the light emitting diode element is sufficiently scattered in the phosphor-containing layer. Further, since the light emitted from the light emitting diode element is sufficiently absorbed by the phosphor particles, the wavelength conversion is performed with high efficiency and the light emitted from the phosphor is irradiated in all directions. Thereby, primary light from a plurality of types of phosphors can be mixed to obtain a desired color (for example, white), and uniform color and illuminance can be obtained. On the other hand, when the median particle diameter (D ₅₀ ) of the phosphor is larger than the above range, the phosphor cannot sufficiently fill the space of the phosphor-containing layer, so that the light emitted from the light emitting diode element is sufficiently fluorescent. May not be absorbed by the body. Moreover, when the median particle diameter (D ₅₀ ) of the phosphor is smaller than the above range, the luminous efficiency of the phosphor is lowered, and the illuminance may be lowered.

  The particle size distribution (QD) of the phosphor particles is preferably smaller in order to align the dispersion state of the particles in the phosphor-containing layer, but in order to reduce the particle size, the classification yield is lowered and the cost is increased. 0.03 or more, preferably 0.05 or more, more preferably 0.07 or more. Moreover, it is 0.4 or less normally, Preferably it is 0.3 or less, More preferably, it is 0.2 or less.

The median particle size (D ₅₀ ) and particle size distribution (QD) can be determined from a weight-based particle size distribution curve. The weight-based particle size distribution curve can be obtained by measuring the particle size distribution by the laser diffraction / scattering method.

[Phosphor mixing method]
The mixing method when the phosphor particles are contained in the sealing member is not particularly limited. For example, if the dispersed state of the phosphor particles is good, it only needs to be post-mixed with the above curable material. That is, a layer may be formed by mixing a curable material and a phosphor and coating them. Further, for example, when hydrolysis / polycondensation of alkylalkoxysilane is used as a curable material, if the phosphor particles are likely to aggregate in the curable material, a reaction solution containing a raw material compound before hydrolysis ( If appropriate, the phosphor particles are mixed in advance in a “pre-hydrolysis solution” below) and subjected to hydrolysis and polycondensation in the presence of the phosphor particles, and the surface of the phosphor particles is partially silane-coupled, The dispersed state of the phosphor particles is improved.

  Some phosphors are hydrolyzable, but when the above-mentioned alkylalkoxysilane hydrolyzate / polycondensate is used as a curable material, the moisture in the fluid state before coating is silanol. Since it exists potentially as a body and there is almost no free water, such a phosphor can be used without being hydrolyzed. Further, if the curable material after hydrolysis / polycondensation is used after being subjected to dehydration / dealcoholation treatment, there is also an advantage that the combined use with such a phosphor becomes easy.

  In addition, when the hydrolyzate / polycondensate of the above alkylalkoxysilane is used as a curable material and phosphor particles or inorganic particles are contained in the curable material, an organic coating is used on the particle surface to improve dispersibility. It is also possible to perform modification with a ligand. Other addition-type silicone resins are susceptible to curing inhibition by such organic ligands, and there are cases where particles subjected to such surface treatment cannot be mixed and cured. This is because platinum-based curing catalysts used in addition-reactive silicone resins have a strong interaction with these organic ligands, tend to lose hydrosilylation ability and cause poor curing. . Such poisonous substances include organic compounds containing multiple bonds, such as organic compounds containing N, P, S, etc., ionic compounds of heavy metals such as Sn, Pb, Hg, Bi, As, acetylene groups, etc. Amines, vinyl chloride, sulfur vulcanized rubber) and the like. On the other hand, the hydrolysis / polycondensation product of the alkylalkoxysilane is based on a condensation-type curing mechanism that hardly causes inhibition of curing by these poisoning substances. For this reason, the hydrolysis / polycondensation products of the above alkylalkoxysilanes have a high degree of freedom in mixing with fluorescent components such as phosphor particles and inorganic particles whose surface has been modified by organic ligands, and complex phosphors. It is large and has excellent characteristics as a phosphor binder and a transparent material with high refractive index nanoparticles.

[Phosphor concentration]
In the integrated mounting region, the concentration of the phosphor in the phosphor-containing layer is preferably a concentration at which light from the light emitting diode element is sufficiently absorbed.
Specifically, the concentration of the phosphor in the curable material is arbitrary as long as the effects of the present invention are not significantly impaired, and can be freely selected depending on the application form. However, the total amount (concentration) of the phosphor in the phosphor-containing layer is usually 5% by weight or more, preferably 6% by weight or more, more preferably 7% by weight or more, and usually 90% by weight or less, preferably 70% by weight. Below, more preferably 40% by weight or less, still more preferably 25% by weight or less, more preferably 20% by weight or less. In the region closest to the light emitting diode, the phosphor concentration in the phosphor-containing layer is preferably 20% by weight or more in order to absorb and disperse the emitted light from the light emitting diode well.

  Further, the concentration of the phosphor in the fluid curable material may be set so that the concentration of the phosphor in the curable material falls within the above range. Therefore, when the fluid curable material does not change in weight in the curable material curing step, the concentration of the phosphor in the curable material is the same as the concentration of the phosphor in the phosphor-containing layer. In addition, when the curable material changes in weight in the curable material curing process, such as when the fluid curable material contains a solvent or the like, the concentration of the phosphor in the curable material excluding the solvent or the like is What is necessary is just to make it become the same as the density | concentration of the fluorescent substance in a fluorescent substance containing layer. When the phosphor-containing layer is composed of a plurality of layers, the above-mentioned phosphor concentration is a value of the average phosphor concentration in the entire phosphor-containing layer.

The phosphor concentration and concentration distribution in the phosphor-containing layer can be calculated from the preparation, and the phosphor-containing layer cured product is chemically dissolved to perform ICP analysis of elements specific to the phosphor, and the cross-section of the cured product is prepared. It can be obtained by performing image processing after taking a picture. An example of obtaining the density distribution by image processing is shown below.
(1) The phosphor-containing layer is peeled off from the LED and cut with a cutter knife or the like to produce a cross section that can be observed in the depth direction.
(2) The cross section of the phosphor-containing layer is irradiated with black light, and a photograph is taken in a state where the phosphor emits light in each color.
(3) The cross-sectional photograph is processed by image processing software, the image is decomposed for each RGB component to obtain an image in which each phosphor is emphasized, and the number of phosphor particles is counted.
(4) A concentration distribution in the depth direction is obtained.

4). Structure of White Semiconductor Light Emitting Device As described above, the white semiconductor light emitting device of the present invention has at least a wiring board, a light emitting diode element, and a phosphor-containing layer that covers these, and the light emitting diode element is a predetermined element. The structure is not particularly limited as long as a predetermined number or more are integrated and mounted in a certain range at an integration density, and may have, for example, a reflection portion or the like. For example, the shape of the phosphor-containing layer may be a dome shape, for example. Further, the phosphor-containing layer may be further covered with a visible light transmissive resin in a dome shape so as to have a lens function.

  As the visible light transmissive resin, for example, an acrylic resin, a silicone resin, or the like can be used, and among these, a silicone resin is particularly preferable. These can be used alone or in combination of two or more. Furthermore, you may make visible light translucent resin contain 1 type, or 2 or more types of additives, such as a viscosity modifier, a diffusing agent, and an ultraviolet absorber, in arbitrary ratios and combinations as needed.

Further, the area of the integrated mounting region in the white semiconductor light emitting device of the present invention is preferably 25 mm ² or more, more preferably 100 mm ² or more, and further preferably 150 mm ² or more. The normally 3600 mm ² or less, preferably 2500 mm ² or less, more preferably 2000 mm ² or less. By setting it within the above range, the apparatus can be miniaturized and a sufficient luminous flux can be obtained.

5. Optical / Electrical Characteristics of White Semiconductor Light Emitting Device The white semiconductor light emitting device of the present invention can emit light in any white color by appropriately determining the type and amount of the phosphor used.
In the semiconductor light emitting device of the present invention, the total luminous flux is 80 (lm) or more, preferably 90 (lm) or more, more preferably 100 (lm) or more.

  Optical / electrical properties are measured by first measuring the white semiconductor light-emitting device to be measured, except for the white semiconductor light-emitting device facing the inside of the integrating sphere (wiring board, heat sink, etc.). Use a spectrophotometer with an integrating sphere, etc. that has a high reflective efficiency such as white. Examples of the spectrophotometer include “USB2000” manufactured by Ocean Optics Co., Ltd. The reason why the integrating sphere is used is to measure and integrate light emitted from the white semiconductor light emitting device in all directions, that is, to eliminate light that is not measured and leaks out of the measurement system.

Next, this white semiconductor light-emitting device is turned on, and its emission spectrum and total luminous flux (lm) are measured. The measured spectrum is usually observed by overlapping the light from the light emitting diode element for excitation leaking from the phosphor-containing layer (hereinafter simply referred to as “excitation light”) and the light wavelength-converted by the phosphor. Is done.
The total luminous flux (lm) can be obtained by integrating the luminous flux for each wavelength in the entire wavelength region where the emission spectrum is observed. The power consumption (W) can be obtained by taking the product of the current (A) flowing through the white semiconductor light emitting device and the voltage (V).
The luminous efficiency can also be obtained by dividing the total luminous flux (lm) obtained as described above by the power consumption (W).

  Further, the input power amount in the white semiconductor light emitting device is obtained by, for example, when n light emitting diode elements are mounted, the input power amount (W) = voltage Vf × current If × n (pieces). Note that the current can be normally set to about 0 (mA) or more and 200 mA or less.

  Further, the average color rendering index Ra of the white semiconductor light-emitting device of the present invention is preferably 80 or more, more preferably 90 or more, and further preferably 95 or more. Thereby, it can be made very excellent in color rendering. For the average color rendering index, Ra is measured according to JIS Z 8726.

  The color temperature of the light emitted from the white semiconductor light emitting device is appropriately selected according to the application and the like, but is usually 2000K or higher, preferably 2500K or higher, more preferably 2700K or higher, and usually 12000K or lower. Preferably it is 10,000K or less, More preferably, it is 7000K or less. By setting it within this range, the appearance of cold and warm colors is good, and it is suitable for applications such as lighting devices.

  Of the light emitted from the white semiconductor light emitting device, the peak intensity of the light emitted from the light emitting diode element is usually not more than twice the maximum value of the visible light spectrum of the emitted light, preferably not more than 1.5 times. is there. By setting it as the above range, the light emission efficiency can be optimized. The light intensity is measured from the spectrum.

6). Use of white semiconductor light-emitting device The use of the white semiconductor light-emitting device of the present invention is not particularly limited, and can be used in various fields in which ordinary light-emitting devices are used. As specific examples of the use of the white semiconductor light emitting device of the present invention, for example, a light source for various illumination devices such as a lamp as a substitute for a conventional illumination lamp such as a halogen lamp, a thin illumination, a light source for an internally illuminated signboard (back Light).

  EXAMPLES Hereinafter, the present invention will be further described with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified without departing from the gist of the present invention. .

[Reference example]
(Production of wiring board)
A plurality of wiring boards having 121 (11 × 11) pad patterns formed in a matrix on a 25 mm × 35 mm aluminum nitride substrate were prepared. The matrix pad patterns were connected such that the column direction was parallel and the row direction was serial, that is, 11 series and 11 parallel.
The position of the pad pattern was adjusted so that the number per unit area per unit area of the light emitting diode element was the value shown in Table 2.

(Formation of light emitting diode element)
As a light emitting diode element (hereinafter referred to as a bare chip or a chip), an InGaN semiconductor having a peak wavelength of 405 nm and a half width of 30 nm as a light emitting layer was used. The main specifications of this bare chip are as follows, and were manufactured as follows.
Structure of light emitting part: MQW structure in which 6 pairs of InGaN well layer / GaN barrier layer are stacked Dislocation density reduction method: facet LEPS method Outline of bare chip: 350 μm × 350 μm square

  Striping patterning with a photoresist was performed on a C-plane sapphire substrate, and etching was performed with a RIE apparatus so as to have a square cross section up to a depth of 1.5 μm, thereby obtaining a substrate having a striped pattern on the surface. The specifications of the pattern were a convex part width of 3 μm, a period of 6 μm, and the longitudinal direction of the stripes in the <11-20> direction for the GaN-based crystal grown on the substrate.

  After removing the photoresist, the substrate was mounted on a normal horizontal atmospheric pressure metalorganic vapor phase epitaxy (MOVPE), and the temperature was raised to 1100 ° C. in a nitrogen gas main component atmosphere to perform thermal cleaning. The temperature is lowered to 500 ° C., trimethylgallium (hereinafter referred to as TMG) as a Group III material, ammonia is flowed as an N material, and a GaN low temperature growth buffer layer having a thickness of 30 nm is formed on a C-plane sapphire substrate on which surface irregularities are formed. Grew.

  Subsequently, the temperature was raised to 1000 ° C., a raw material (TMG, ammonia) and a dopant (silane) were flowed, and an n-type GaN layer (contact layer) was grown on the GaN low-temperature growth buffer layer. The growth of the GaN layer at this time is a growth in which the entire surface is formed without forming a cavity in the concave portion after generating from a top surface of the convex portion and a bottom surface of the concave portion as a ridge-like crystal having a mountain-shaped cross section and including a facet surface. there were.

  A flat GaN buried layer is grown via the facet structure, and then an n-type AlGaN cladding layer, an InGaN light emitting layer (MQW structure), a p-type AlGaN cladding layer, and a p-type GaN contact layer are formed in this order, and the emission wavelength Using an epitaxial substrate for LED of 405 nm, etching processing for exposing an n-type contact layer, electrode formation, and element separation into 350 μm × 350 μm chips were performed to obtain bare-chip light-emitting diode elements.

A stud bump was formed on each wiring board by a bump bonder corresponding to the electrode position of the light emitting diode element, and the light emitting diode element was mounted on the stud bump using a flip chip bonder. Table 2 shows the number per unit area per unit area and the gap between each light emitting diode element. As a sealing material containing no phosphor, only the following sealing material liquid (solvent-free silicone resin) was applied to the entire surface of the chip mounting region by 1.2 mm.
Since the drive current value per light emitting diode element is set to 20 mA, 11 light emitting diode elements are connected in series to each wiring board, so that a current of 220 mA flows (the input power amount at this time is About 8W). Table 2 shows the voltage (Vf), radiant flux (W), and external quantum efficiency (%) during energization.

The optical / electrical properties were measured using a 10 inch integrating sphere LMS-100 manufactured by Labosphere.
The external quantum efficiency was obtained from calculation by dividing the measured total radiant flux by the applied energy (eV equivalent to 405 nm).

[Example]
-Encapsulant liquid Momentive Performance Materials Japan GK ending terminal silanol dimethyl silicone oil XC96-723 385g, methyltrimethoxysilane 10.28g, and zirconium tetraacetylacetonate powder as catalyst. 791 g was weighed into a 500 ml three-necked Kolben equipped with a stirring blade, a fractionating tube, a Dimroth condenser, and a Liebig condenser, and stirred at room temperature for 15 minutes until the coarse particles of the catalyst were dissolved. Thereafter, the temperature of the reaction solution was raised to 100 ° C. to completely dissolve the catalyst, and initial hydrolysis was performed while stirring at 500 rpm for 30 minutes at 100 ° C. under total reflux.

Subsequently, the distillate was connected to the Liebig condenser side, nitrogen was blown into the liquid with SV20, and methanol, water, and low-boiling silicon components of by-products were distilled off with nitrogen accompanying at 100 ° C. and 500 rpm for 1 hour. Stir. The polymerization reaction was continued for 5.5 hours while the temperature was further raised and maintained at 130 ° C. while blowing nitrogen into the liquid with SV20 to obtain a reaction liquid having a viscosity of 389 mPa · s. Here, “SV” is an abbreviation for “Space Velocity” and refers to the volume of blown volume per unit time. Thus, SV20 refers to blowing N ₂ in a volume 20 times that of the reaction solution in one hour.

  Nitrogen blowing was stopped and the reaction solution was once cooled to room temperature, then transferred to an eggplant-shaped flask, and methanol and moisture remaining in a minute amount at 120 ° C. and 1 kPa for 20 minutes on an oil bath using a rotary evaporator. The low boiling silicon component was distilled off to obtain a solvent-free sealing material liquid having a viscosity of 584 mPa · s.

(Formation of phosphor-containing layer)
Each color phosphor-containing layer forming paste for covering the light emitting diode element and the wiring board similar to the reference example was prepared by the following composition.
Blue paste Blue phosphor 30.0% by weight
Green paste Green phosphor 12.5% by weight
Red paste Red phosphor 5.0% by weight
(Wt% is the ratio to thermosetting silicone sealing resin)
As a blue phosphor, Ba _0.7 Eu _0.3 MgAl ₁₀ O ₁₇ , a main emission peak peak wavelength of 457 nm, and a weight median diameter of 11 μm are used.
As a green phosphor, Ba _1.39 Sr _0.46 Eu _0.15 SiO ₄ , a peak wavelength of 525 nm of a main emission peak, and a weight median diameter of 20 μm are used.
As the red phosphor, (Sr _0.8 Ca _0.2 ) AlSiN ₃ : Eu, a main emission peak peak wavelength of 628 nm, and a weight median diameter of 13 μm were used.
The above-mentioned sealing material liquid was used as the silicone sealing resin.

After blending, in order to enhance dispersibility, the mixture was dispersed by a rotation / revolution type vacuum devolatilizer.
The coating of each color was performed using a vacuum printing apparatus in which the substrate on which the chip was mounted was brought into close contact with a mask cut into a planar shape to be coated, and the paste could be coated with a squeegee. First, a red paste is applied to the entire surface of the chip mounting area, heated at 100 ° C. for 1 minute to form a tack-free coating, then printed with a green paste, heated at 100 ° C. for 1 minute in the same manner as the red paste, and then A blue paste layer was formed in the same process. In addition, the film thickness of each paste can be adjusted with the thickness of a mask, and almost all the layers were 0.4 mm. Further, after that, the phosphor-containing layer having a three-layer structure of a blue phosphor layer, a green phosphor layer, and a red phosphor layer on the substrate on which the light emitting diode is mounted is heated at 150 ° C. for the main curing. Formed.
Since the drive current value per one light emitting diode element is set to 20 mA as in the reference example, 11 light emitting diode elements are connected in series to each wiring board, so that a current of 220 mA flows. Table 3 shows power consumption (W), radiant flux (W), luminous flux (lm), luminous efficiency (lm / W), color temperature (K), and average color rendering index (Ra) of the white semiconductor light emitting device in each example. Show.

Radiant flux and optical / electrical properties were measured using a 10 inch integrating sphere LMS-100 manufactured by Labosphere. Luminous efficiency was determined by dividing the luminous flux by the input power. The color temperature and average color rendering index were calculated from the spectrum.
When the phosphor was mixed in the sealing liquid, the radiant flux from the light emitting device decreased due to the conversion efficiency of the phosphor as compared with the case where the phosphor was coated with the transparent sealing material. However, it has been clarified that a desired radiant flux and luminous efficiency can be obtained while maintaining high color rendering properties by appropriately taking a gap distance between the light emitting diode elements.

上記結果から、駆動電流を増加させると、全放射束が電流にほぼ比例して、頭打ちとなることなく増加することがわかる。 Table 4 shows changes in the total radiant flux when the drive current is increased for each example. A graph showing these relationships is shown in FIG.

From the above results, it can be seen that when the drive current is increased, the total radiant flux increases substantially in proportion to the current without peaking.

上記結果から、駆動電流を増加させると、全放射束が電流にほぼ比例して、頭打ちとなることなく増加していることがわかる。 Table 5 shows changes in the total luminous flux when the drive current is increased for each example. A graph showing these relationships is shown in FIG.

From the above results, it can be seen that when the drive current is increased, the total radiant flux increases substantially in proportion to the current without peaking.

上記結果から、駆動電流を増加させても、色温度が安定していることがわかる。 Table 6 shows the change in color temperature when the drive current is increased for each example.

From the above results, it can be seen that the color temperature is stable even when the drive current is increased.

上記結果から、駆動電流を増加させても、平均演色評価数は安定していることがわかる。 Further, Table 7 shows changes in the average color rendering index when the drive current is increased for each example.

The above results show that the average color rendering index is stable even when the drive current is increased.

  The white semiconductor light-emitting device of the present invention is highly integrated with light-emitting diode elements, and is compact and capable of extracting a large luminous flux. Therefore, it is useful as a light source for various illumination devices such as an illumination lamp and a thin illumination, and a light source (backlight, front light, etc.) for an image display device such as a liquid crystal display.

DESCRIPTION OF SYMBOLS 1 ... Wiring board 2 ... Light emitting diode element 3 ... Phosphor containing layer 10 ... White semiconductor light-emitting device

Claims (10)

A wiring board;
A plurality of light emitting diode elements mounted directly on the wiring board and having an emission wavelength in the range of 360 nm to 480 nm;
A white semiconductor light-emitting device having a phosphor-containing layer containing a phosphor that emits light when excited by light emitted from the light-emitting diode element,
100 or more of the light emitting diode elements are integrated and mounted on a 10 cm ² region on the wiring board,
The number per unit area of the light emitting diode elements is integrated and mounted at 16 / cm ² or more and 1000 / cm ² or less,
A white semiconductor light-emitting device, wherein the light-emitting diode element mounted in an integrated manner is covered with the phosphor-containing layer. The white semiconductor light-emitting device according to claim 1, wherein the light-emitting diode element is flip-mounted. 3. The white semiconductor light emitting device according to claim 1, wherein a gap between adjacent light emitting diode elements of the integrally mounted light emitting diode elements is 0.05 mm or more and 2.0 mm or less. The white semiconductor light-emitting device according to claim 1, wherein the light-emitting diode elements integrated and mounted are electrically connected in series and parallel. 5. The white semiconductor light-emitting device according to claim 1, wherein the concentration of the phosphor in the phosphor-containing layer is 5 wt% or more and 90 wt% or less. The white semiconductor light-emitting device according to claim 1, wherein a distance between centers of adjacent light-emitting diode elements is 0.1 mm or more and 2.0 mm or less. 7. The white semiconductor light emitting device according to claim 1, wherein an area of each light emitting diode element is 20000 μm ² or more and 360000 μm ² or less. The white semiconductor light-emitting device according to claim 1, wherein the wiring board is a heat dissipation board. The phosphor-containing layer is
A layer containing a red phosphor that is excited by light emitted from the light emitting diode element and emits red light;
A layer containing a green phosphor that is excited by light emitted from the light emitting diode element and emits green light;
A layer containing a blue phosphor that is excited by light emitted from the light emitting diode element and emits blue light;
The white semiconductor light-emitting device according to claim 1, wherein the white semiconductor light-emitting devices are stacked in this order from the light-emitting diode element side. An illumination device comprising the white semiconductor light-emitting device according to claim 1.

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