JP2015012194A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device capable of effectively using the light emitted from a side surface of a light emitting element for excitation of a fluophor.SOLUTION: A light emitting device comprises: a package having a concave X; a light emitting element 20 mounted in the concave X of the package; a translucent member 30 provided above the light emitting element 20; an encapsulation resin 40 for encapsulating the concave X of the package; and fluophors 50 in the encapsulation resin 40. The fluophors 50 are distributed in the side of the light emitting element 20 more than above the light emitting element, and the side surface of the light emitting element 20 is exposed to the encapsulation resin 40.

Description

  The present invention relates to a light emitting device.

  Conventionally, a light emitting device has been proposed in which a phosphor is provided in a recess of a package on which a light emitting element is mounted (see Patent Document 1).

JP 2008-103688 A

  However, the conventional light emitting device has a problem that it is difficult to take out light emitted from the upper surface of the light emitting element from the concave opening of the package because the amount of the phosphor distributed above the light emitting element is large.

  In addition, since the conventional light emitting device has a small amount of phosphor distributed on the side of the light emitting element, the light emitted from the side surface of the light emitting element passes through the recess side wall of the package without being used for excitation of the phosphor. There was a problem that it was easy to get out of the package.

  Therefore, the present invention provides a light emitting device in which a larger amount of phosphor is distributed on the side of the light emitting element than above the light emitting element, and light emitted from the side surface of the light emitting element can be efficiently used for excitation of the phosphor. For the purpose.

  According to the present invention, the above problem is solved by the following means.

  A package having a recess; a light emitting element mounted in the recess of the package; a translucent member provided above the light emitting element; a sealing resin for sealing the recess of the package; and the sealing A phosphor contained in a resin, wherein the phosphor is distributed more to the side of the light emitting element than above the light emitting element, and the side surface of the light emitting element is sealed A light-emitting device that is exposed to resin.

It is a schematic diagram which shows schematic structure of the light-emitting device which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows schematic structure of the light-emitting device which concerns on Embodiment 2 of this invention. It is a schematic diagram which shows schematic structure of the light-emitting device which concerns on Embodiment 3 of this invention. It is a schematic diagram of the side view type light-emitting device which can apply Embodiments 1-3 of this invention preferably. It is a schematic diagram of the top view type light-emitting device which can preferably apply Embodiments 1-3 of the present invention.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated, referring attached drawing.

[Light Emitting Device According to Embodiment 1 of the Present Invention]
FIG. 1 is a schematic diagram illustrating a schematic configuration of a light-emitting device according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the light emitting device according to Embodiment 1 of the present invention is provided above a package 10 having a recess X, a light emitting element 20 mounted in the recess X of the package 10, and the light emitting element 20. The light emitting device includes a translucent member 30, a sealing resin 40 that seals the recess X of the package 10, and a phosphor 50 contained in the sealing resin 40. The light emitting device is distributed more on the side of the light emitting element 20 than above the element 20, and the side surface of the light emitting element 20 is exposed to the sealing resin 40.

  Hereinafter, it demonstrates in order.

(Package 10)
Examples of the package 10 include thermoplastic resins such as PPA (polyphthalamide), PPS (polyphenylene sulfide), liquid crystal polymer, and nylon, epoxy resins, silicone resins, modified epoxy resins, modified silicone resins, urethane resins, or In addition to thermosetting resins such as acrylate resins, glass epoxy resins, ceramics, glass, and the like can be used. As the ceramic, it is preferable to use alumina, aluminum nitride, mullite, silicon carbide, silicon nitride, or the like. In particular, highly reflective and inexpensive alumina and mullite are preferable.

  The recess X included in the package 10 has a bottom surface X3 that is flat enough to mount the light emitting element 20 and has a shape that can be filled with the sealing resin 40. An example of such a recess X is a trapezoidal recess (see FIG. 1). According to the package 10 having the trapezoidal concave section (see FIG. 1), the light emitted from the light emitting element 20 is reflected by the concave section side wall X2 toward the concave section opening X1, thereby improving the light extraction efficiency of the light emitting device. .

(Light emitting element 20)
For the light emitting element 20, for example, a light emitting diode can be used. For example, a light emitting diode having an insulating and translucent growth substrate (eg, sapphire substrate) and a laminated structure including an active layer formed on the growth substrate is used. it can. Note that the stacked structure including the active layer is formed of various semiconductors (eg, nitride semiconductors such as InN, AlN, GaN, InGaN, AlGaN, and InGaAlN, III-V compound semiconductors, II-VI compound semiconductors). be able to.

  Although the mounting method of the light emitting element 20 is not particularly limited, for example, the light emitting element 20 can be mounted in the recess X of the package 10 with the growth substrate side as a mounting surface. In this case, the light emitting element 20 is electrically connected to the external electrode of the package 10 by wire bonding, for example. On the other hand, the light emitting element 20 can be mounted in the recess X of the package 10 with the stacked structure side including the active layer as a mounting surface. In this case, the light emitting element 20 is electrically connected to the external electrode of the package 10 by, for example, flip chip mounting.

  The side surface of the light emitting element 20 is exposed to the sealing resin 40. Even if the phosphor 50 is distributed more on the side of the light emitting element 20 than above the light emitting element 20, if the translucent member 30 covers the side surface of the light emitting element 20, the light is emitted from the side surface of the light emitting element 20. Since the light is reflected (particularly totally reflected) by the translucent member 30, the light emitted from the side surface of the light emitting element 20 cannot be efficiently used for exciting the phosphor 50. However, if the side surface of the light emitting element 20 is exposed to the sealing resin 40, the side surface of the light emitting element 20 is not covered with the translucent member 30, so that light emitted from the side surface of the light emitting element 20 is phosphor 50. It can be used efficiently for excitation of.

(Translucent member 30)
As the translucent member 30, a member having a property of transmitting light from the light emitting element 20 is used. Although the degree of transmission is not particularly limited, the translucent member 30 is, for example, about 70% or more, about 80% or more, or about 90% or more in addition to a member that transmits 100% of light emitted from the light emitting element 20. Alternatively, it is preferable to use a member having a property of transmitting about 95% or more.

  As the translucent member 30, it is preferable to use a member having light resistance and insulation in addition to the property of transmitting light from the light emitting element 20. Examples of members having such properties include silicone resins, epoxy resins, urea resins, fluororesins, and organic substances such as hybrid resins containing at least one or more of these resins (eg, silicone resin compositions, modified silicone resin compositions). Product, epoxy resin composition, modified epoxy resin composition, acrylic resin composition) and the like.

  The translucent member 30 only needs to be provided above the light emitting element 20, but the phosphor distributed in a region sandwiched between the translucent member 30 and the light emitting element 20 among the light emitting element 20. 50 is preferably provided at a position where the amount is reduced, and more preferably provided on the upper surface of the light emitting element 20 as shown in FIG. Thereby, since the amount of the phosphor 50 distributed above the light emitting element 20 decreases (or becomes 0), the frequency at which the light emitted from the upper surface of the light emitting element 20 is reflected by the phosphor 50 decreases, It becomes easy to take out the light emitted from the upper surface of the light emitting element 20 from the recess opening X1 of the package 10.

  As the translucent member 30, a member having a surface that prevents the phosphor 50 from being deposited is preferably used. Thereby, since the amount of the phosphor 50 distributed above the light emitting element 20 decreases (or becomes 0), the frequency at which the light emitted from the upper surface of the light emitting element 20 is reflected by the phosphor 50 decreases, It becomes easy to take out the light emitted from the upper surface of the light emitting element 20 from the recess opening X1 of the package 10.

  Further, the translucent member 30 includes a member that protrudes with respect to the recess opening X1 of the package 10 (see FIG. 1), a member that has a height close to the recess opening X1 of the package 10 (see FIG. 2), and light emission. In addition to a member that protrudes with respect to the element 20 (eg, inverted trapezoidal shape), it is preferable to use a member in which these shapes are combined.

  The member that is convex with respect to the concave opening X1 of the package 10 has a trapezoidal shape, a dome shape, and a semi-cylindrical shape (the curved surface of the bisected cylinder is directed to the concave opening X1 of the package 10, and the planar side is the light emitting element. However, it is preferable to use a member having a shape in which the light from the light emitting element 20 is difficult to totally reflect. As an example of such a member, when the height of the sealing resin 40 is about 100 μm, a lens-type member having a curvature radius of 0.66 mm in the long side and 0.16 mm in the short side can be mentioned. .

  The member that is convex with respect to the concave opening X1 of the package 10 is preferably provided by potting and curing a thermosetting resin on the upper surface of the light emitting element 20, for example. If it does in this way, the convex surface will become a shape which prevents deposition of the fluorescent substance 50 by the surface tension of a thermosetting resin.

  The surface of the translucent member 30 is preferably provided with a fine structure such as irregularities and microlenses. In this way, since reflection at the interface between the translucent member 30 and the sealing resin 40 is reduced, the light extraction efficiency of the light emitting device is improved. In addition, since the sealing resin 40 is not yet cured in the formation process and easily spreads around, the phosphor 50 does not accumulate on the light-transmitting member 30 even if the light-transmitting member 30 is uneven (see FIG. Or only a small amount is collected).

(Sealing resin 40)
For the sealing resin 40, for example, a material similar to the above-described translucent member 30 can be used.

  The sealing resin 40 is provided, for example, by curing a resin potted in the recess X of the package 10.

  The height of the light emitting element 20, the height of the translucent member 30, and the height of the sealing resin 40 are (the height of the sealing resin 40−the height of the light emitting element 20−the translucent member 30. It is preferable to have a relationship of (height) ≦ 300 μm, and (the height of the sealing resin 40−the height of the light emitting element 20−the height of the light-transmitting member 30) ≦ 150 μm. More preferably, the relationship of (height of sealing resin 40−height of light emitting element 20−height of translucent member 30) ≦ 50 μm is more preferable. Thereby, since the amount of the phosphor 50 distributed above the light emitting element 20 decreases (or becomes 0), the frequency at which the light emitted from the upper surface of the light emitting element 20 is reflected by the phosphor 50 decreases, It becomes easy to take out the light emitted from the upper surface of the light emitting element 20 from the recess opening X1 of the package 10.

(Phosphor 50)
More phosphors 50 are distributed on the side of the light emitting element 20 than above the light emitting element 20. As a result, the amount of the phosphor 50 distributed above the light emitting element 20 is smaller than the amount of the phosphor 50 distributed to the side of the light emitting element 20 (or becomes 0). The frequency with which the emitted light is reflected by the phosphor 50 is reduced, and the light emitted from the upper surface of the light emitting element 20 is easily extracted from the recess opening X1 of the package 10. In addition, since the amount of the phosphor 50 distributed on the side of the light emitting element 20 is larger than the amount of the phosphor 50 distributed above the light emitting element 20, the light emitted from the side surface of the light emitting element 20 is emitted from the phosphor 50. It can be used efficiently for excitation. In addition, when the light emitted from the side surface of the light emitting element 20 is efficiently used for excitation of the phosphor 50, the light emitted from the side surface of the light emitting element 20 is difficult to reach the recess side wall X2 of the package 10. It is possible to suppress the light emitted from the side surface 20 from passing through the recess side wall X2 of the package 10 and going out of the package 10.

  As an example of the distribution, a form in which the phosphor 50 is deposited on the bottom surface X3 of the recess 10 of the package 10 as shown in FIG. Such a form can be formed, for example, by precipitating the phosphor 50 in the recess X of the package 10 before the sealing resin 40 is cured.

  For the phosphor 50, a fluorescent material that emits light when excited by light emitted from the light emitting element 20 can be used. As the fluorescent material, a material that emits light having a shorter wavelength than the light emitted from the light emitting element 20 can be used, but a material that emits light having a longer wavelength is more preferably used. In this way, since the phosphor can be made to emit light efficiently, the light extraction efficiency of the light emitting device is improved.

  Examples of the phosphor that emits light having a longer wavelength than the light emitted from the light emitting element 20 include nitride phosphors and oxynitride phosphors mainly activated by lanthanoid elements such as Eu and Ce. Specifically, Eu activated α or β sialon phosphors, various alkaline earth metal nitride silicate phosphors, lanthanoid elements such as Eu, alkalis mainly activated by transition metal elements such as Mn Earth metal halogen apatite phosphor, alkaline earth halosilicate phosphor, alkaline earth metal silicate phosphor, alkaline earth metal borate phosphor, alkaline earth metal aluminate phosphor, alkaline earth metal Lanthanoid elements such as acid salts, alkaline earth metal sulfides, alkaline earth metal thiogallate, alkaline earth metal silicon nitride, germanate, and Ce Organic and organic complexes mainly activated by lanthanoid elements such as rare earth aluminate, rare earth silicate or Eu which are mainly activated can be used. However, fluorescent materials having the same performance and effects as these fluorescent materials can also be used. When a nitride semiconductor light emitting element is used as the light emitting element 20, for example, a phosphor (fluorescent substance) such as a YAG fluorescent substance (yellow fluorescent substance) or a LAG fluorescent substance (yellow fluorescent substance) is used. Is preferred.

  When the phosphor 50 is deposited on the side of the light emitting element 20 lower than the active layer of the light emitting element 20, the light emitted from the side surface of the lower region (eg, growth substrate) of the light emitting element 20 than the active layer. Is incident on the phosphor 50 immediately after emission, so that the light emitted from the side surface of the region below the active layer (eg, the growth substrate) in the light emitting element 20 can be efficiently used for excitation of the phosphor 50. It becomes.

  On the other hand, when the phosphor 50 is deposited on the side of the light emitting element 20 higher than the active layer of the light emitting element 20, it is emitted from the side surface of the region below the active layer in the light emitting element 20 (eg, growth substrate). In addition to the emitted light, the light emitted from the side surface of the active layer of the light emitting element 20 is incident on the phosphor 50 immediately after the emission, and therefore, the side surface of the region below the active layer (eg, the growth substrate) in the light emitting element 20. The light emitted from the light and the light emitted from the side surface of the active layer of the light emitting element 20 can be efficiently used for excitation of the phosphor 50.

[Light Emitting Device According to Embodiment 2 of the Present Invention]
FIG. 2 is a schematic diagram showing a schematic configuration of a light emitting device according to Embodiment 2 of the present invention.

  As shown in FIG. 2, the light emitting device according to the second embodiment of the present invention has a point where the light emitting element 20 is flip-chip mounted and a height at which the translucent member 30 is close to the recess opening X1 of the package 10. This is different from the light emitting device according to Embodiment 1 of the present invention.

  In the light emitting device according to Embodiment 2 of the present invention, as in the light emitting device according to Embodiment 1 of the present invention, the phosphors 50 are distributed more on the side of the light emitting element 20 than above the light emitting element 20, The side surface of the light emitting element 20 is exposed to the sealing resin 40.

(Translucent member 30)
The translucent member 30 has a height close to the recess opening X1 of the package 10. Thereby, since the amount of the phosphor 50 distributed above the light emitting element 20 decreases (or becomes 0), the frequency at which the light emitted from the upper surface of the light emitting element 20 is reflected by the phosphor 50 decreases, Light emitted from the upper surface of the light emitting element 20 can be easily taken out from the recess opening X1 of the package 10.

  The distance between the upper surface of the translucent member 30 and the recess opening X1 of the package 10 is about 100 μm, or the distance between the translucent member 30 and the recess opening X1 of the package 10 is the thickness of the translucent member 30. If the distance between the translucent member 30 and the recess opening X1 of the package 10 is shorter than the thickness of the light emitting element 20, the translucent member 30 is close to the recess opening X1 of the package 10. It is an example in the case of having a thickness.

  The translucent member 30 is preferably affixed to the upper surface of the light emitting element 20. For example, when a light emitting diode having positive and negative electrodes on the same surface side is used, the translucent member 30 can be easily attached to the upper surface of the light emitting element 20.

[Light Emitting Device According to Embodiment 3 of the Present Invention]
FIG. 3 is a schematic diagram showing a schematic configuration of a light emitting device according to Embodiment 3 of the present invention.

  As shown in FIG. 3, the light emitting device according to Embodiment 3 of the present invention is different from the light emitting device according to Embodiment 1 of the present invention in that the phosphor 50 is not deposited on the bottom surface X3 of the recess 10 of the package 10. .

  In the light emitting device according to Embodiment 3 of the present invention, as in the light emitting device according to Embodiment 1 of the present invention, the phosphors 50 are distributed more on the side of the light emitting element 20 than above the light emitting element 20, The side surface of the light emitting element 20 is exposed to the sealing resin 40.

  As described above, in the light emitting devices according to Embodiments 1 to 3 of the present invention, the phosphor 50 is distributed more on the side of the light emitting element 20 than above the light emitting element 20, and the side surface of the light emitting element 20 is sealed with the sealing resin. 40, the light emitted from the upper surface of the light emitting element 20 can be easily taken out from the recess opening X1 of the package 10, and the light emitted from the side surface of the light emitting element 20 is efficiently used for exciting the phosphor 50. Can be used. Therefore, according to Embodiments 1 to 3 of the present invention, the light extraction efficiency of the light emitting device can be improved.

  The first to third embodiments of the present invention can be particularly preferably applied to a light emitting device in which an electrode such as a pad electrode or ITO is provided on the upper surface of the light emitting element 20. According to the first to third embodiments of the present invention, since the frequency of the light emitted from the upper surface of the light emitting element 20 being reflected by the phosphor 50 is reduced, the light reflected by the phosphor 50 above the light emitting element 20 is padded. The light extraction efficiency of the light-emitting device can be improved by suppressing absorption by an electrode such as an electrode or ITO.

  In the first to third embodiments of the present invention, even if a reflecting member is provided, the light emitting device (e.g., the concave portion of the package 10) has a thin concave portion side wall X2 so that light passes through the concave portion side wall X2. The present invention can be particularly preferably applied to a light emitting device in which the thickness of the side wall X2 is about 0.1 mm. According to the first to third embodiments of the present invention, the light emitted from the side surface of the light emitting element 20 can be prevented from passing through the recess side wall X2 of the package 10 and coming out of the package 10. The light extraction efficiency can be improved in the light emitting device in which the thickness of the concave sidewall X2 is small.

  The first to third embodiments of the present invention can also be preferably applied to the light emitting element 20 using ceramics for the package 10. Ceramics is an inorganic material and has little deterioration and high reliability. However, the reflectance is lower than that of a resin material containing a light-reflecting member and the light from the light-emitting element 20 is easily transmitted. 1 to 3, since light emitted from the side surface of the light emitting element 20 can be prevented from passing through the recess side wall X <b> 2 of the package 10 and going out of the package 10, ceramics is used for the package 10. In the light emitting device, light extraction efficiency can be improved.

  FIG. 4 is a schematic view of a side-view type light emitting device to which Embodiments 1 to 3 of the present invention can be preferably applied. FIG. 4 (a) is a schematic plan view, and FIG. 4 (b) is a diagram (a). The schematic diagram of an AA cross section in FIG. 4, FIG.4 (c) is the schematic diagram of the BB cross section in (a).

  The embodiment of the present invention can also be applied to a side view type light emitting device as shown in FIG. 4, for example. In the side view type light emitting device shown in FIG. 4, the translucent member 30 is potted on the upper surface of the light emitting element 20 after electrically connecting the light emitting element 20 to the external electrode of the package 10 by wire bonding using the wire 60. The wire 60 protrudes from the translucent member 30.

  FIG. 5 is a schematic view of a top-view light-emitting device to which Embodiments 1 to 3 of the present invention can be preferably applied. FIG. 5 (a) is a schematic plan view, and FIG. 5 (b) is (a). FIG. 5C is a schematic diagram of the DD cross section in FIG. 5A.

  The embodiment of the present invention can also be applied to a top view type light emitting device as shown in FIG. 5, for example. The top view type light emitting device shown in FIG. 5 includes a plurality of light emitting elements 21 and 22, and the light emitting elements 21 and 22 are provided with translucent members 31 and 32, respectively. The light emitting elements 21 and 22 are connected in series using a wire 60, and both ends of the wire 60 connecting the light emitting element 21 and the light emitting element 22 are covered with translucent members 31 and 32, respectively. The phosphor 50 is distributed not only between the light emitting elements 21 and 22 and the side wall X2 of the package 10, but also between the light emitting element 21 and the light emitting element 22.

  As mentioned above, although embodiment of this invention was described, these description is related with an example of this invention, and this invention is not limited at all by these description.

DESCRIPTION OF SYMBOLS 10 Package 20 Light emitting element 21 Light emitting element 22 Light emitting element 30 Translucent member 31 Translucent member 32 Translucent member 40 Sealing resin 50 Phosphor 60 Wire X Recess X1 Recess opening X2 Recess side wall X3 Recess bottom

Claims (9)

A package having a recess; a light emitting element mounted in the recess of the package; a translucent member provided above the light emitting element; a sealing resin for sealing the recess of the package; and the sealing A light-emitting device comprising a phosphor contained in a resin,
A light emitting device characterized in that the phosphor is distributed more on the side of the light emitting element than above the light emitting element, and the side surface of the light emitting element is exposed to the sealing resin.   The light emitting device according to claim 1, wherein the phosphor is deposited on a bottom surface of the recess of the package.   The light-emitting device according to claim 1, wherein the translucent member has a surface that prevents deposition of the phosphor.   The light-emitting device according to claim 1, wherein the translucent member is convex with respect to a concave opening of the package.   5. The light emitting device according to claim 1, wherein the translucent member has a height close to a recess opening of the package.   The light emitting device according to claim 1, wherein the translucent member is provided on an upper surface of the light emitting element.   The light emitting device according to claim 6, wherein the translucent member is attached to an upper surface of the light emitting element.   The light emitting device according to claim 1, wherein the phosphor is deposited lower than an active layer of the light emitting element. The light emitting device according to any one of claims 1 to 7, wherein the phosphor is deposited higher than an active layer of the light emitting element.

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