JP5738257B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device used for LED lighting or the like, and more particularly to a light emitting device including a semiconductor light emitting element that emits blue light, violet light, and ultraviolet light and a phosphor that converts the light into white light.

  In recent years, lighting devices using LEDs have been put into practical use and are being replaced by incandescent bulbs and fluorescent lamps as well as mercury lamps and halogen lamps. The reason is that the same brightness can be obtained with low power consumption, and it becomes a trump card for eco-products that can significantly reduce the amount of carbon dioxide emissions that cause global warming. For example, the equivalent brightness of a 60W class incandescent bulb can be realized with a 9W LED bulb. In this way, if all lighting is replaced by LED lighting, the reduction target of carbon dioxide emissions can be easily achieved, but the obstacle is that the price difference between the two lighting devices is still large. It is. Considering the lifespan, the price difference is quite small, so lighting in special places can be replaced with LED lighting because it can also reduce labor costs to replace it, but general lighting with the most needs However, the initial price gap is still large, which is preventing the spread.

There are two main reasons why LED bulbs are expensive. One of them is that the drive power source for LED bulbs is a DC constant current power source, and a converter from AC is required. The light emitting device (also referred to as a white LED device) itself is expensive. The reason why the white LED device is expensive is that the material cost is high and the yield is poor. The material cost of the white LED device is from the higher occupancy to the package, the LED element, the phosphor, and the resin, and the main factor that deteriorates the yield of the white LED device is chromaticity (or color temperature). ) Yield (that is, the non-defective product rate for obtaining the target chromaticity deteriorates due to variations in the amount of the phosphor). Companies selling white LED devices are making efforts to reduce prices from this perspective.

One example is the approach of CREE as shown in US Pat. Conventionally, after mounting a semiconductor light emitting element (also referred to as an LED element or LED chip) on the package, the light emitting device is manufactured by sealing the inside of the package with a resin mixed with phosphor powder. When the chromaticity inspection of the light emitting device is NG, the entire light emitting device including the package becomes NG, and even the most expensive package is discarded. In contrast, in Patent Document 1, as shown in FIG. 5 (a) (b), the light extraction surface, except for the wire bond pads 131 of the LED element 139 (Moshiku is included to the side surface of the LED element 139) The white LED element 130 on which the phosphor layer 138 is formed. In this case, the chromaticity inspection can be performed at the stage of the LED element 139 , and the expensive package indicated by reference numeral 134 in FIG. 5C is not discarded . Furthermore, since the phosphor is used only in the range of the surface of the LED element 139 , the phosphor can be saved. Furthermore, since the chromaticity is determined by the point light source of the LED element 139, the chromaticity variation due to the directivity angle of the white LED device is also improved.

Similar efforts are made in Patent Documents 2 and 3.
In Patent Document 2, as shown in FIG. 6A, a chip assembly 142 in which a phosphor chip 141 is bonded to a LED chip with a transparent resin is mounted on a package by a flip chip method, or in another example. Or wire bonding (mounting with the electrode surface facing up, and connecting to the substrate by wire bonding). Moreover, in patent document 3, as shown in FIG.6 (b), except a bump front-end | tip part of the LED chip which has the bump 146 in a mounting part (electrode part), it coat | covers with the resin which mixed fluorescent substance powder, and has a structure. The body 147 is mounted in a cavity having a reflection wall 148 using a conductive adhesive on the bump portion and sealed with a transparent resin. These two examples are also examples aiming at the same improvement as in Patent Document 1.

Special table 2010-517289 JP 2002-141559 A JP 2002-261325 A

  As shown in Patent Documents 1, 2, and 3, for the purpose of improving the variation in chromaticity depending on the directivity angle by saving phosphors, improving the yield of chromaticity, and white point light emitters, The concept of a white light emitting element (also referred to as a white LED element) has appeared. As shown in FIG. 5C, the white light emitting element 130 is mounted on a plate-shaped package substrate 133 (specifically, a ceramic aluminum oxide substrate) having a moderate thermal conductivity, and a resin lens. The light-emitting device 132 that is sealed with 134 and collects light in a target direction can be manufactured at low cost, and its structure is being established as a light-emitting device for illumination that also has brightness, heat dissipation, and reliability. . However, in terms of component configuration, the highest package substrate is reduced in size with the idea of being as cheap as possible without losing the characteristics as much as possible, eliminating the structure of the reflecting wall, and being replaced by condensing by the resin lens 134. However, the high package substrate 133 is still the largest size among the components.

In the case of FIG. 5 (c), specifically speaking, the main cause for having to enlarge the package substrate (ceramic aluminum oxide substrate or aluminum nitride substrate) is that the light from the white LED element 130 is directed in a certain direction. In order to collect the light, it is indispensable to form a lens. In the conventional method, the lens is formed on the package substrate 133. Therefore, the lens cannot be formed unless the package substrate is made the largest.
Further, even when the reflection wall is formed as shown in FIG. 6B, the package substrate is the largest because it is formed on the substrate.
From the viewpoint of effective use of light, the function of directing light in a certain direction is an important element for ecological lighting, and this function is more effective as it is placed closer to the light source. That is, it is more effective to place the reflecting wall in the light emitting device than to place the reflecting wall around the light emitting device. Therefore, a light collecting function is given to the package in the light emitting device.

Further, if the size of the package substrate 133 is evaluated from the viewpoint of heat dissipation, the thermal conductivity of the ceramic aluminum oxide substrate or the aluminum nitride substrate is isotropic, so if it is considered that heat spreads around the same distance as the thickness When the size of the heat dissipation electrode of the LED element is a square with a side of 1 mm and the thickness of the substrate is 0.5 mm, the size of the package substrate necessary for heat dissipation is sufficient with a square with a side of 2.0 mm. It is. However, the size of the package substrate 133 of the light-emitting device shown in FIG. 5 is as large as a square with a side of 3.45 mm.

  Thus, the package substrate has a resin structure in which the LED element is molded (that is, a phosphor-containing resin mixed with a phosphor powder covering the LED element, a transparent resin or a phosphor-containing resin filled in the reflection wall) The white resin mixed with the white pigment forming the reflection wall, and the transparent resin forming the lens, etc.) must be larger.

  The present invention has been made in view of the above circumstances, and in particular, the size of a package substrate having a high share of material cost is made as small as possible (in a range that satisfies heat dissipation), and an LED element is molded. The resin structure is larger than the package substrate, and the characteristics are also improved by making the light emitted from the LED element focused in a certain direction and the light extraction efficiency better than before. Another object of the present invention is to provide a light-emitting device that is more inexpensive.

The present invention relates to a light emitting device in which a semiconductor light emitting element is flip-chip mounted on a substrate, and the semiconductor light emitting element is formed in a trapezoidal shape with a light extraction surface smaller than an electrode forming surface facing the substrate, and the side surface is inclined. On the light extraction surface of the semiconductor light-emitting element, a substantially central portion of a phosphor-containing film piece larger than the substrate is attached, and from the peripheral part of the phosphor-containing film piece that protrudes from the semiconductor light-emitting element , In the meantime, a resin transparent to the light emitted from the semiconductor light-emitting element is filled to form an inverted quadrangular pyramid structure, and a white resin is filled outside the structure, so that the structure The light emitting device is characterized in that a reflecting wall is formed at the interface between the white resin and the white resin .
As a result , the size of the package substrate having a high share of the material cost is made as small as possible (in a range satisfying heat dissipation), and the resin structure in which the LED element is molded is formed to be larger than the package substrate. By adopting a structure in which the light emitted from the element is condensed at a level equal to or higher than that of the conventional structure, characteristics can be improved and a light-emitting device can be obtained at lower cost.

As a method of obtaining white light using a semiconductor light emitting element, YAG phosphor powder that emits yellow light having a complementary color with blue light was used in the early days. However, the pseudo white light produced by the blue light of the semiconductor light emitting device and the yellow light of the YAG phosphor has a low average color rendering index Ra of about 70 units, and reproduces the natural color of the object by the illumination. Was impossible. Therefore, as a second step, phosphor powder that emits green light and red light, which are the three primary colors of blue light, is used, and the blue light of the semiconductor light emitting element and the broad light from the two types of phosphors are used. White light is composed of green light and red light having a spectrum, the average color rendering index Ra is improved to 93, and the color reproducibility by illumination is considerably improved. If the brightness of the semiconductor light emitting element emitting violet light or ultraviolet light further increases, three kinds of phosphor powders that emit three primary colors of light with violet light or ultraviolet light are used. Moreover, in order to improve color reproducibility, a plurality of phosphors may be mixed.
In order to obtain a white light emitting device for illumination, a resin portion containing the above-described phosphor may be placed in the resin structure.
Of course, a light emitting device that emits light from a semiconductor light emitting element without using a phosphor may be used.

By the way, there are various resin structures in which the semiconductor light emitting element is molded. For example, in the case of FIG. 1, a phosphor-containing resin (phosphor-containing film piece) 3 on the upper surface of the LED chip 2, a transparent resin 7 on the side surface, and a white resin (reflective) mixed with fine titanium oxide powder on the outside. Wall) 6. Moreover, in FIG. 2, it is comprised by the fluorescent substance containing film piece 13 of the upper surface of LED chip 2, the reflective wall 16 of a side surface, and the resin lens 18 which consists of transparent resin on it. Further, in FIG. 3, the trapezoidal LED chip 32 is configured with a phosphor-containing film piece 33 on the upper surface, a transparent resin 37 on the inclined surface, and a reflection wall 36 on the outer side (in FIG. 4, a transparent resin lens 38 on the upper side). Has been.
In particular, in FIGS. 3 and 4 according to the present invention, the resin structure for molding the semiconductor light emitting element is a combination of a transparent resin portion having an inverted quadrangular pyramid shape and a white resin portion mixed with a white pigment. Such resin structure is formed by protruding a substrate 3 4, the reflecting wall and the transparent resin lens can be made large formed without being limited to the substrate 3 4, is possible to improve the light extraction efficiency it can.

Specifically, the flip chip mounting emits blue light, violet light, or ultraviolet light, has two main surfaces facing each other, one main surface is a light extraction surface, and the other main surface is an electrode formation surface, The semiconductor light emitting device having bumps on the electrode forming surface has two main surfaces that are equal to or larger than the electrode forming surface, and a pair of chip mounting electrodes (+ electrode and − electrode) on one main surface. A pair of external substrate mounting electrodes (+ electrode and − electrode) are formed on the other main surface, and the + electrode and the − electrode on each main surface are conductively connected by through holes. It consists of a double structure mounted on the chip mounting electrode via the bump . Therefore, in the present invention, the has two major surfaces larger face than the light extraction surface of the double structure, the one main surface and the light incident surface, fluorescent powders you the other main surface and the light exit surface A phosphor-containing resin mixed with (referred to as a phosphor-containing film piece) is disposed so that the light extraction surface and the light incident surface are opposed to each other, and from the semiconductor light emitting element in the phosphor-containing film piece A space between the protruding peripheral portion and the substrate is filled with a resin transparent to the light emitted from the semiconductor light emitting element to form an inverted quadrangular pyramid-shaped structure, and on the outside of the structure, the double layer is formed. Exposed surfaces other than the main surface (or the main surface and the vicinity thereof) on which the external substrate mounting electrode of the structure is formed, and the light exit surface (or the light output surface and the vicinity thereof) of the phosphor-containing film piece are White resin mixed with white pigment (with reflective wall Covered with that), the interface between the structure and the said white resin Ru Tei is formed reflecting wall. By adopting such a structure, an expensive substrate can be minimized, and the light extraction efficiency can be improved without limiting the reflecting wall to the substrate size.

And most of the light emitted from the pn junction of the double-structured LED chip comes out from the light extraction surface, and from the light incident surface of the phosphor-containing film piece arranged to overlap the surface. Then, the phosphor enters the phosphor-containing film piece, causes the phosphor to emit light, and the total light exits from the light exit surface and is used as white light for illumination. In addition, the phosphor concentration of the phosphor-containing film piece is adjusted appropriately, and most of the light emitted from the LED chip is converted into the light emission peculiar to the phosphor. It can also be set as the light-emitting device which emits a color or red.

In the present invention, you and forming a resin lens having a diameter which encloses the outer shape of the output light surface on the light exit surface of the phosphor-containing film piece. According to this configuration , the light extraction efficiency is further improved, the luminous flux value is increased by about 7 to 8%, and high luminance can be achieved.

Furthermore, in the present invention, it characterized by using a transparent resin film pieces instead of the phosphor-containing film piece. According to this configuration, it is possible to provide a light emitting device that emits the light color of the LED chip as it is, and by appropriately selecting the light emission color of the LED chip, the LED chip emits light with high output that can be used for various applications. Thus, an inexpensive light emitting device of ultraviolet light, visible light, or infrared light having a sharp spectrum can be obtained. A light-emitting device that emits high-power infrared light can also be used as a heating device with low power consumption.

Moreover, in this invention, the area | region of the said fluorescent substance containing film piece is divided | segmented, and one fluorescent substance is selected among blue fluorescent substance, green fluorescent substance, red fluorescent substance, and yellow fluorescent substance for every divided | segmented area | region. One assigned, characterized in that it constitutes a phosphor-containing film piece.
According to said structure, when an LED element is blue light, when a green fluorescent substance and a red fluorescent substance are mixed and manufactured to the said fluorescent substance containing film piece, interaction arises between these fluorescent substances. That is, the green light having a broad spectrum from the green phosphor excited by the light from the LED element is again absorbed by the red phosphor and the intensity thereof is greatly reduced. To prevent this, for example, as shown in FIG. 7, the area of the phosphor-containing film piece is divided into multiple divided areas 71 of the region 72 and the red phosphor of the green phosphor is formed (isolation phosphor by serial and film piece), the interaction can be prevented, correspondingly, Ki out to improve the color rendering of the light emitting device (Ra and R9), it is possible to also improve luminance. When the LED element is ultraviolet light or violet light, a blue phosphor is also used, so the interaction between the blue phosphor and the green phosphor, the yellow phosphor, the red phosphor, etc. becomes remarkable, so the separation type effect Will increase further.

In the light emitting device of the present invention, the size of the package substrate having a high share of the material cost is made as small as possible (to the extent that heat dissipation is satisfied), and the resin structure in which the LED chip is molded is smaller than the package substrate. The light emitting device can be formed in a large size and has a function for condensing light emitted from a light emitting element in a certain direction and a light extraction efficiency that is as good as or better than conventional ones. Can be provided.
Further, since the phosphor-containing film piece is placed on the light extraction surface of the semiconductor light-emitting device, the white light-emitting device saves the use of an extra phosphor and is a white point light emitter. The chromaticity variation due to the directivity angle can also be improved.
Furthermore, the exposed surface other than the light emitting surface of the phosphor-containing film piece and the surface where the external substrate mounting electrode is formed on the double-structured substrate are covered with a reflecting wall, and light that travels in directions other than the light emitting surface direction (especially semiconductors) The light going to the side surface of the light emitting element, the light going to the side surface of the phosphor-containing film piece, etc. are dispersed and reflected by the reflecting wall and collected in a certain direction. Further, since the reflecting wall is formed in close contact with the light emitting source (that is, at a short distance), the reflecting wall can be efficiently reflected and condensed, and the brightness can be increased. Further, the light extraction efficiency is further improved by the resin lens.
Further, the region of the phosphor-containing film piece is divided into several parts, and a blue phosphor, a green phosphor, a red phosphor, and a yellow phosphor are separated and formed for each divided region (referred to as a separated phosphor film piece). Thus, the interaction between the phosphors can be prevented, and the color rendering properties and luminance of the light emitting device can be improved.

Moreover, by applying the structure of the present invention not only to a white light emitting device but also to a single color semiconductor light emitting device, a high output light emitting device corresponding to the three primary colors of light having a broad spectrum peculiar to phosphor emission, an LED It becomes possible to manufacture a high-power light emitting device with ultraviolet light, visible light, or infrared light having a sharp spectrum peculiar to chip light emission.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure of the light-emitting device of 1st Embodiment of this invention, Comprising: (a) is the top view seen from the top, (b) is the top view seen from the bottom, (c) is sectional drawing in line AA It is. It is a figure of the light-emitting device of 2nd Embodiment of this invention, Comprising: (a) is the top view seen from the top, (b) is the top view seen from the bottom, (c) is sectional drawing in line BB It is. It is sectional drawing of the light-emitting device of 3rd Embodiment of this invention. It is sectional drawing of the light-emitting device of 4th Embodiment of this invention. It is a figure which shows the light-emitting device of a prior art, Comprising: (a) (b) is a white light emitting element, (c) is a light-emitting device. It is sectional drawing which shows the light-emitting device of a prior art. It is a figure which shows the separation type phosphor film piece of this invention.

  Hereinafter, embodiments of a light-emitting device of the present invention will be described in detail in the order of first to sixth embodiments with reference to the drawings.

First, the light-emitting device of 1st Embodiment is shown in FIG.
This light-emitting device 1 emits blue light, and has a plating bump of 10 μm thickness on an n-side electrode (−electrode) and a p-side electrode (+ electrode) (Au strike plating on a 10 μm-thick Ni plating). The 3W-class blue LED element 2 on which is formed is mounted on the chip mounting electrodes (E1, F1) of the ceramic aluminum oxide substrate (or aluminum nitride substrate) 4 via plating bumps to form a double structure. The size of the substrate 4 is about 0.5 mm in thickness in consideration of heat dissipation, and the size is a square having a side of about 2 mm (in consideration of cost) and is slightly larger than the LED chip. The chip mounting electrodes (E1, F1) formed on the double structure substrate and the external substrate mounting electrodes (E2, F2) E1-E2 and F1-F2 are conductively connected by through holes.
On the upper surface (light extraction surface) of the blue LED element 2 of the double structure, the light incident surface of the phosphor-containing film piece 3 made by mixing phosphor powder into silicon resin and having a rectangular shape is bonded with silicon resin. The size of the phosphor-containing film piece 3 is a square having a thickness of about 0.1 mm and a side of about 2.4 mm.
On the side surface of the blue LED element 2, an inverted quadrangular pyramid-shaped structure 7 having a phosphor-containing film piece 3 as a bottom surface is formed of silicon resin.
Further, the external substrate mounting electrode forming surface of the double-structured substrate 4 and the exposed surface other than the light exit surface of the phosphor-containing film piece 3 are covered with a white resin 6 in which a fine powder of titanium oxide is mixed with a silicon resin, and a reflecting wall To form a light emitting device 1.
This structure is different from the conventional structure in which the substrate 4 is embedded in white resin and the resin structure is formed on the conventional substrate. The board | substrate 4 mounts the LED element 2, is stopped to the minimum magnitude | size required in order to thermally radiate the heat | fever which generate | occur | produces in the LED element 2, and can suppress the material cost of an expensive board | substrate.
The luminance (light flux: lumen value) of the light emitting device 1 having this structure greatly depends on the size (width) of the phosphor-containing film piece 3. For example, in the case of a 3W-class LED element 2, the size of the phosphor-containing film piece 3 is most bright and bright (the lumen value is large) when the side of the square is 2.4 mm to 3.0 mm square. )Become. Below that, the light extraction efficiency becomes poor and dark (the lumen value is small). In other words, the phosphor-containing film piece 3 needs to be larger than the substrate, and this is possible with the structure of the present invention, and the luminance and other optical characteristics can be equal to or higher than those of the conventional structure. is there.

  The LED element 2 emits a GaN-based compound semiconductor film from the substrate side on the surface of a translucent crystal substrate (for example, sapphire substrate, SiC substrate, GaN substrate, etc.), and emits blue light. The p-type electrode was laminated on the p-type layer surface, the p-type electrode was formed on the surface of the p-type layer, and the p-type layer and the light-emitting layer were partially selectively etched to form the n-type electrode on the exposed portion of the n-type layer. However, the p-side electrode and the n-side electrode are formed on substantially the same plane, although there are steps of several μm. The surfaces of these electrodes are Au films, and when they are in a wafer state, they can be electrolessly plated in the order of Pd, Ni, Au (for surface protection), and have a height of approximately 10 μm (preferably 20 μm). Form bumps. Most of the height is Ni.

The phosphor-containing film piece 3 is obtained by, for example, mixing two types of phosphor powders with resin-type silicone, forming a film and curing it, and dividing it into a rectangular shape. Is a phosphor that is excited by blue light and emits green light (for example, CaSc ₂ O ₄ : Ce), and the other phosphor is a phosphor that is excited by blue light and emits red light (for example, (SrCa) AlSiN ₃ : Eu). The blending amount is adjusted to, for example, a color temperature of about 3000 K, which is close to a light bulb color. The color temperature can be selected by changing the blending amount. Resin-type silicone has a high refractive index (1.5 to 1.55), a hardness of Shore D (40 to 70, preferably 60 to 70), and good transparency (for example, a light transmission wavelength of 450 nm). When the thickness of the resin is 1 mm, 95% or more, preferably 99% or more) is used.

The reflecting wall 6 is obtained by, for example, mixing a fine powder of titanium oxide having a particle diameter of 0.21 μm with resin-type silicone and curing it. Titanium oxide has a large dielectric constant and high light reflectivity, so it is often used as a reflection wall. However, because of its photocatalytic properties, it is excited by ultraviolet light or blue light, and acts on surrounding moisture and oxygen. ₂ H radicals and OH radicals are made, and the silicone resin is deteriorated and discolored. Therefore, the reflective wall around the blue LED element changes color from white, and the luminance deteriorates to 80% or less in several tens of hours. Therefore, the titanium oxide fine particles used here are those whose surface is coated with silica or alumina or whose properties of the photocatalyst are prevented by siloxane treatment. In addition, the blending ratio with the silicone resin is about 5 to 30% in terms of pigment volume concentration, and it is also necessary to prevent a decrease in reflectance due to the dense effect. Resin type silicone has a high refractive index (1.5 to 1.55), a hardness of Shore D (50 to 70, preferably 60 to 70), and good transparency (for example, light transmittance is high). When the resin thickness is 1 mm with respect to blue light having a wavelength of 450 nm, 95% or more, preferably 99% or more) is used. The thickness of the reflecting wall is about 60 μm or more on the side surface of the phosphor-containing film piece 3 and about 100 μm or more on the side surface side of the LED element 2. These values are merely examples and are not limited to these.

  Adhesion between the LED element 2 and the phosphor-containing film piece 3 uses resin-type silicone used for the phosphor-containing film piece. An appropriate amount of the phosphor for correcting chromaticity and color temperature may be mixed in the silicon resin.

Next, the light emitting device of the second embodiment is shown in FIG.
The light emitting device 10 has the same double structure as that of the first embodiment, but uses a resin lens 18 to increase the light extraction efficiency.
In the case of the first embodiment, the cone-shaped reflection wall 5 and the broad phosphor-containing film piece 3 are used in order to improve the light extraction efficiency. In the case of the second embodiment, the cone-shaped reflection is used. Although the wall is not used and the size of the phosphor-containing film piece 13 is slightly larger than that of the LED element 2, the light extraction efficiency can be improved by using a wider convex resin lens 18. This is better than the light emitting device 1 of the embodiment.

As in the first embodiment, a 3W-class blue LED element 2 is mounted on the substrate 4 to form the double structure, and then the upper surface (light extraction surface) of the blue LED element 2 contains a phosphor. The light incident surface of the film piece 13 is bonded with silicon resin. The size of the phosphor-containing film piece 13 is a square having a thickness of about 0.1 mm and a side of about 1.5 mm.
Further, the external substrate mounting electrode forming surface of the double structure substrate 4 and the exposed surface other than the light exit surface of the phosphor-containing film piece 13 are covered with a white resin to form the reflecting wall 16. At this time, the upper surface of the reflection wall 16 is flush with the light exit surface of the phosphor-containing film piece 13.
Further, a convex resin lens 18 having a diameter that encloses the light exit surface of the phosphor-containing film piece 13 is formed on the flush surface. The diameter of the convex resin lens 18 is about 2 mm to about 3 mm, which is larger than that of the phosphor-containing film piece 13 to improve the light extraction efficiency.
Due to the effect of the resin lens 18, the luminance (light flux: lumen value) of the light emitting device 10 having this structure becomes brighter than that of the light emitting device 1 of the first embodiment.
The size of the light emitting device 10 is determined by the size of the resin lens 18. For example, when the diameter of the resin lens 18 is about 2.0 mm, the size of the light emitting device 10 is a square having a side of about 2.4 mm. When the diameter is about 3 mm, one side is about 3.4 mm. The latter has better light extraction efficiency.

Next, FIG. 3 shows a cross-sectional view of the light emitting device of the third embodiment. This cross-sectional view is a cross-sectional view at a position corresponding to the line AA of the first embodiment.
The light emitting device 30 is substantially the same as the light emitting device 1 of the first embodiment, except that the 3W-class blue LED element 32 used is different. The blue LED element 32 has a trapezoidal shape in which the light extraction surface is smaller than the electrode formation surface and the side surface is inclined, and light extraction from this surface is also considered. Therefore, the structure 37 is formed in the same manner as the inverted quadrangular pyramid-shaped structure 7 of the light emitting device 1 of the first embodiment, and the light extraction from the inclined surface is made favorable.
In this case, the phosphor-containing film piece 33 has a thickness of about 0.1 mm and a side of about 2.4 mm to about 3.0 mm.

Next, FIG. 4 shows a cross-sectional view of the light emitting device of the fourth embodiment. This cross-sectional view is a cross-sectional view at a position corresponding to the line BB in the second embodiment.
The light emitting device 40 uses a trapezoidal 3W-class blue LED element 32 as in the light emitting device 30 of the third embodiment. A convex resin lens 38 having a lens diameter larger than that of the phosphor-containing film piece is formed on the phosphor-containing film piece 33 of the light emitting device 30 to further improve the light extraction efficiency.
The phosphor-containing film piece 33 used in the light emitting device 40 has a thickness of about 0.1 mm, a square with a side of about 2.4 mm, and a resin lens diameter of about 3.4 mm. is there.

Next, the light emitting device according to the fifth embodiment is the same as the light emitting device shown in FIGS. 1 to 4, instead of the phosphor-containing film pieces 3, 13, and 33, as shown in FIGS. It is a light-emitting device using the separate type | mold phosphor film piece as shown by.
This light-emitting device has almost no interference between phosphors (for example, in the case of a phosphor-containing film in which green phosphors and red phosphors are mixed, interference such that red phosphors absorb light emitted by green phosphors again). The color rendering index Ra or R9 showing the color rendering properties can be increased, and the light emission efficiency is improved because there is no two-stage absorption in which the red phosphor absorbs the light emitted from the green phosphor again.
The separation shape of the phosphor is shown in FIG. 7, but it may be a single circle or square as shown in (a) or (b), a plurality of circles or squares, or a shape other than a circle or square. good. Further, as shown in (c) and (d), it may be divided by a cross line or a horizontal or vertical line.

Next, the light emitting device according to the sixth embodiment is a transparent resin film made of a silicon resin in which no phosphor is mixed, instead of the phosphor containing film pieces 3, 13, and 33 in the light emitting devices of FIGS. 1 to 4. Is a light emitting device using
This light-emitting device is characterized by the light of the LED element itself that is used (ultraviolet light, visible light, infrared light) and a spectrum of light having a narrow half-value width unique to the LED element.

1, 10, 30, 40 Light-emitting device 2,32 Semiconductor light-emitting element (LED element or LED chip)
3,13,33 Phosphor-containing film piece 4,34 Substrate 5 Reflecting wall slope 6, 16, 36, 76 Reflecting wall 18, 38 Resin lens 71, 72 Divided area of phosphor-containing film piece E1, F1, E2, F2, G1, H1, G2, H2 electrodes

Claims (4)

In a light emitting device in which a semiconductor light emitting element is flip-chip mounted on a substrate,
The semiconductor light emitting element is formed in a trapezoidal shape with a light extraction surface smaller than the electrode formation surface facing the substrate, and the side surface is inclined,
On the light extraction surface of the semiconductor light emitting element, a substantially central portion of a phosphor-containing film piece larger than the substrate is attached,
A space between the substrate and a portion of the phosphor-containing film piece that protrudes from the semiconductor light emitting element is filled with a resin transparent to the light emitted from the semiconductor light emitting element to form an inverted quadrangular pyramid structure. ,
A light emitting device , wherein a white resin is filled outside the structure, and a reflection wall is formed at an interface between the structure and the white resin . Wherein on the light plane out of the phosphor-containing film piece, light-emitting device according to claim 1, wherein the forming a resin lens having a diameter which encloses the outer shape of the output light plane. The light emitting device according to claim 1 or 2 , wherein a transparent resin film piece is used instead of the phosphor-containing film piece. A region of the phosphor-containing film piece is divided, and for each divided region, one phosphor of blue phosphor, green phosphor, red phosphor, and yellow phosphor is allocated, and the phosphor The light-emitting device according to claim 1 , wherein the light-emitting device constitutes a containing film piece.

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