JP5660766B2 - Light emitting device - Google Patents

Description

  The present invention relates to a display device and a light emitting device that can be used as a light source of a lighting fixture.

  Research on light-emitting devices (LEDs) that use semiconductor light-emitting elements (hereinafter simply referred to as light-emitting elements) as a new light source to replace fluorescent lamps and incandescent bulbs that have been used in the past as light sources for display devices and lighting devices It has been. Since this LED has a longer life than the above light source and can emit light with energy saving, it is highly expected as a light source for next generation illumination.

  In particular, white light emitting devices are expected to be most in demand, and are equipped with red, blue, and green light emitting elements to emit white light, and light emitting elements, which are excited to become complementary colors. One that emits white light using a phosphor capable of emitting color is known.

  When used as general illumination, when a red, blue, or green light emitting element is used, the color rendering property is lowered. Therefore, a white light emitting device using a phosphor is preferred. In particular, a blue light emitting element and white using a YAG phosphor are well known.

  Since this YAG phosphor has a yellow body color, there is no particular problem during light emission, but the yellow color is visible when the light is turned off. When using a mobile phone or general lighting, in addition to functions such as brightness and color rendering, shape and design are also important factors when selecting, so it may be avoided to see such yellow color. .

  Therefore, there are known methods such as mixing a diffusing material that fades yellow, or covering with a cap containing a diffusing material.

JP 2005-183193 A

    However, the structure as described above can improve the visibility somewhat, but is not sufficient. Further, a structure that improves the visibility by covering the light emitting device itself with another member can be used, but the number of members increases, there is a limit to downsizing, and the cost also increases.

In order to achieve the above object, a light-emitting device according to claim 1 of the present invention includes a substrate, a light-emitting element placed on the substrate, and a wavelength conversion member whose body color is chromatic, and emits light. A sealing member that covers the element, and a translucent member that is bonded onto the substrate and encloses the sealing member via the hollow portion, and the translucent member includes two or more translucent members. It is characterized in that the achromatic member of the body color of the wavelength conversion member is sandwiched between them.

  In the light emitting device according to claim 3 of the present invention, the sealing member preferably has an outer surface similar in shape to the inner surface of the translucent member.

  In the light emitting device according to claim 4 of the present invention, it is preferable that the distance between the outer surface of the sealing member and the inner surface of the translucent member is substantially equal over the entire circumference.

In the light emitting device according to claim 5 of the present invention, it is preferable that the achromatic member includes at least one of SiO ₂ and Al ₂ O ₃ .

  According to the present invention, it is possible to obtain a light-emitting device that is difficult to visually recognize a chromatic color caused by a phosphor and has excellent design. Furthermore, since it is possible to obtain a light emitting device with reduced color unevenness and orientation color temperature difference, it is possible to obtain a miniaturized light emitting device that does not require a separate member.

FIG. 1A is a perspective view showing the whole and the inside of a light emitting device according to the present invention. 1B is a cross-sectional view of the light emitting device according to FIG. 1A taken along the line A-A ′.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the form shown below illustrates the light-emitting device for embodying the technical idea of the present invention, and is not limited to the following.

  Further, the present specification by no means specifies the member shown in the claims as the member of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention only to the extent that there is no specific description. It is just an example. It should be noted that the size and positional relationship of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate.

  A light-emitting device 100 of the present embodiment is shown in FIGS. 1A and 1B. 1A is a perspective view showing the whole and the inside of the light emitting device 100, and FIG. 1B is a cross-sectional view of the light emitting device 100 shown in FIG.

  In this embodiment mode, the light-emitting device 100 includes a light-emitting element 103, a substrate 101 having a conductive member 102 that is electrically connected to the light-emitting element 103, and the light-emitting element 103, as shown in FIGS. 1A and 1B. And a sealing member 104 covering the surface. Further, a translucent member 105 that encloses the sealing member 104 via the hollow portion X is bonded onto the substrate 101. In the present invention, the sealing member 104 has a wavelength conversion member whose body color is chromatic, and the translucent member 105 makes it difficult to visually recognize the body color of the wavelength conversion member from the outside. It has a non-achromatic member.

  In the present specification, the “body color” means an emission color emitted by being excited by ultraviolet light to blue light under sunlight or general illumination (for example, standard light D65) containing ultraviolet light to blue light components. Indicates a color that is visible.

(Translucent member)
In the present invention, the translucent member is positioned on the uppermost surface of the light emitting device, and is visually recognized as a light emitting portion when energized (when emitting light), and has an internal presence when turned off (when not emitting light). It has an achromatic member for achromatic (whitening) so that the color is not visually recognized.

  As shown in FIGS. 1A and 1B, the translucent member 105 is bonded to the upper surface of the substrate 101 so as to be separated from the sealing member 104, and is provided so as to enclose the sealing member 104 through the hollow portion X. It has been. The achromatic member (not shown) may be provided at least on the outer surface, the inner surface, or the inner portion of the translucent member 105, and is preferably provided on the inner surface of the translucent member.

  The shape and size of the translucent member 105 can be variously selected according to the purpose and application, and the outer shape is hemispherical (dome shape), cube, rectangular parallelepiped, cylinder, polygonal column, cone, etc. It can be set as the shape which combined. Preferably, the translucent member has a hemispherical outer shape as shown in FIGS. 1A and 1B. The inner shape can be variously selected in the same manner as the outer shape, and the inner shape and the outer shape can be the same shape (similar shape) or different shapes. Preferably, the outer shape and the inner shape are similar, and as shown in FIG. 1A, the outer shape is preferably a hemispherical shape, and the inner shape is also preferably a hemispherical shape. By doing so, the thickness of the translucent member can be made uniform, so that a light-emitting device with little alignment unevenness can be obtained.

  As a preferable material of the translucent member, a material that easily transmits light from the light-emitting element and has a strength that can withstand normal use is preferable. Examples thereof include glass, epoxy resin, and silicone resin. In particular, glass is preferred.

As the achromatic member provided in such a translucent member, it is preferable that the light from the light emitting element or the wavelength conversion member is not easily absorbed during light emission and is easily reflected. What is visually recognized as white) is preferable. Specifically, fine powders such as SiO ₂ , TiO ₂ , and Al ₂ O ₃ can be mentioned, and those having a particle size of about 0.5 μm to 50 μm are particularly preferable. These may be used alone, or may be used by mixing or laminating a plurality, and the particle size, concentration, mixing ratio, etc. of each member can be appropriately selected.

  The achromatic member is preferably provided so as to obtain an equivalent achromatic effect over almost the entire area of the translucent member, and is preferably provided with a uniform film thickness, concentration, and the like.

  When it is provided on the outer or inner surface of the translucent member, a wet method such as a dispersion method in which the achromatic member is dispersed in a solvent is dropped, sprayed, and then the solvent is scattered by heating, a sol-gel method, a sheet shape For example, a method of attaching a film or a dry method such as sputtering can be used, and the film thickness can be controlled by adjusting the conditions. The preferred film thickness depends on the composition and particle size of the achromatic member to be used, but it is necessary to adjust so that the internal chromatic color is not visually recognized and the light from the light emitting element is not extremely blocked, For example, it is preferably about 0.1 mm to 0.5 mm, more preferably about 0.2 mm to 0.3 mm.

  When the achromatic member is provided on the inner surface of the translucent member, it is provided before the translucent member is joined to the substrate. By providing it on the inner surface, the achromatizing member is unlikely to be peeled off or damaged during bonding to the substrate, and when it is handled as a light emitting device, it can be prevented from being peeled off or damaged because it is not directly touched.

  When the achromatic member is provided on the outer surface of the translucent member, it can be formed in any step before or after the translucent member is joined to the substrate. In particular, when the achromatic member is provided after bonding to the substrate, the achromatic member can also be provided on the upper surface of the substrate. For example, to recognize the bonding position of the translucent member as shown in FIG. 1A. The mark 106 on the upper surface of the substrate to be provided can be covered.

  When the achromatic member is provided inside the translucent member, it is mixed at the time of forming the translucent member, or two or more translucent members are overlapped, and the achromatic member is sandwiched between them. Can be used. In the case of mixing, it is necessary to consider the concentration of the achromatic member so that the light transmittance from the light emitting element is not extremely lowered during light emission.

(substrate)
The substrate is a base on which electronic components such as a light emitting element and a translucent member are placed, and is provided with a conductive member for conducting to the light emitting element. The size and shape of the substrate can be set arbitrarily according to the purpose and application. For example, as shown in FIG. 1A, in addition to a substantially square shape in top view, a rectangle, a polygon, a circle, and a combination thereof. Shapes can be used. Preferred materials include glass epoxy resins, ceramics, thermosetting resins, thermoplastic resins, Al, Cu, etc., and combinations thereof, for example, those in which Cu is embedded in ceramics, etc. Can do. A glass epoxy resin is preferable. Further, a surface treatment such as covering the upper surface with a member that hardly absorbs light may be performed.

(Conductive member)
The conductive member is a pair of positive and negative electrodes for energizing the light emitting element or the like, and is provided so as to be exposed on the upper surface and the lower surface of the substrate and to be continuous inside or on the surface of the substrate. The shape and size of the conductive member can be arbitrarily selected according to the size of the light emitting device and the number and size of the light emitting elements to be mounted. In FIG. 1A, the light emitting element 103 and the protective element 107 are placed on the conductive member 102 and are joined so as to be electrically connected via a conductive wire (not shown). Further, as shown in FIG. 1A, it is preferable that the upper surface of the substrate is provided (exposed) at a position where it is covered with the sealing member 104, whereby the conductive wire can be protected by the sealing member. The shape of the conductive member can be made difficult to visually recognize by the sealing member. In addition, it is preferable to cover the translucent member 105 with an insulating member or the like at a position where the translucent member 105 is bonded, and also on the upper surface of the substrate outside the bonding position of the translucent member 105 with an insulating member or the like. It is preferable to coat it.

  Specific materials for the conductive member include metals such as copper, aluminum, gold, silver, tungsten, iron, nickel, and cobalt, or eutectic such as iron-nickel alloy, phosphor bronze, iron-containing copper, molybdenum, and Au-Sn. Examples thereof include solder, solder such as SnAgCu and SnAgCuIn, and ITO. Among these solder materials, those that are adjusted to a composition that is not re-dissolved during additional heat treatment such as reflow mounting, especially when the composition is controlled and once melted and solidified by the reaction between the solder particles and the first metal part are preferable.

(Sealing member)
The sealing member is a member that protects electronic components such as a light emitting element, a light receiving element, a protective element, and a conductive wire from dust, moisture, and external force. In the present invention, the sealing member contains a wavelength conversion member. Is.

  As a material for the sealing member, a material having a light-transmitting property capable of transmitting light from the light-emitting element and having light resistance that is not easily deteriorated by them is preferable. Specific examples of the material include a silicone resin composition, a modified silicone resin composition, an epoxy resin composition, a modified epoxy resin composition, and an acrylic resin composition. A composition can be mentioned. Furthermore, a silicone resin, an epoxy resin, a urea resin, a fluororesin, and a hybrid resin containing at least one of these resins can also be used. Furthermore, it is not limited to these organic materials, and inorganic materials such as glass and silica sol can also be used. In addition to such a material, in addition to the wavelength conversion member (fluorescent member), a colorant, a light diffusing agent, a light reflecting material, various fillers, and the like can be included as desired. The filling amount of the sealing member may be an amount that covers the electronic component.

  Further, when a translucent member having an achromatic member is used, the chromaticity may change as compared with a case where the translucent member is not used. This is considered to be caused by the fact that the light reflected by the achromatic member or the like is easily irradiated with the wavelength conversion member again, that is, the amount of light that is wavelength-converted increases. It is done. Therefore, the amount of the wavelength conversion member can be reduced as compared with the case where the achromatic member is not used to emit light having the same color tone.

  The shape of the outer surface of the sealing member can be variously selected according to the light distribution characteristics. In FIG. 1A, the cylindrical sealing member 104 is used. However, the present invention is not limited to this. For example, the directivity can be adjusted by making the upper surface into a convex lens shape, a concave lens shape, a Fresnel lens shape, or the like. . Particularly preferred is an outer surface similar in shape to the inner surface of the translucent member, which makes it easier to obtain uniform orientation characteristics. In addition, it is preferable that the distance between the outer periphery of the sealing member and the inner surface of the translucent member be substantially equal over the entire periphery, which makes it easy to obtain an achromatic effect evenly.

(Joining member)
The joining member is an adhesive member for placing and connecting an element such as a light emitting element, a light receiving element, a protective element, or a light transmitting member on a conductive member. In the case of an element such as a light emitting element, the bonding member can be either insulating or conductive, and can be appropriately selected depending on the element substrate to be used. As the insulating bonding member, an epoxy resin composition, a silicone resin composition, a polyimide resin composition, a modified resin thereof, a hybrid resin, or the like can be used. As the conductive bonding member, a conductive paste such as silver, gold or palladium, a solder such as Au—Sn eutectic, or a brazing material such as a low melting point metal can be used.

  The bonding member for bonding the translucent member to the substrate is preferably one that easily transmits or reflects light from the light emitting element or the wavelength conversion member, and particularly preferably has a transmittance of 70% or more. Moreover, what has a value close | similar to the thermal expansion coefficient of a board | substrate and a translucent member is preferable. Specifically, an epoxy resin composition, a silicone resin composition, a polyimide resin composition, a modified resin thereof, a hybrid resin, or the like can be used. Moreover, you may mix the achromatic member provided in a translucent member, etc. in this joining member.

(Conductive wire)
Examples of the conductive wire (not shown) for connecting the electrode of the light emitting element and the conductive member provided on the substrate include conductive wires using metals such as gold, copper, platinum, and aluminum, and alloys thereof. In particular, it is preferable to use gold excellent in thermal resistance.

(Wavelength conversion member)
The wavelength conversion member emits light having a different wavelength by absorbing at least part of the light from the light emitting element. In the present invention, at least the body color is red, blue, green, yellow or the like. It has a chromatic color.

  As the wavelength conversion member, it is more efficient to convert light from the light emitting element into a longer wavelength. However, the present invention is not limited to this, and various wavelength conversion members such as one that converts light from the light emitting element into a short wavelength or one that further converts light converted by another wavelength conversion member can be used. . As such a wavelength conversion member, only one type of wavelength conversion member may be used, or two or more types of wavelength conversion members may be mixed or laminated. Moreover, you may use the wavelength conversion member from which a body color and a light emission wavelength differ in that case.

For example, when a semiconductor light emitting device using a nitride semiconductor as a light emitting layer is used as the light emitting device, any light emitting device that absorbs light from the light emitting device and converts it into light of a different wavelength may be used. For example, nitride phosphors / oxynitride phosphors mainly activated by lanthanoid elements such as Eu and Ce, more specifically, Eu-activated α or β sialon phosphors, various alkaline earths Metal nitride silicate phosphors, lanthanoid elements such as Eu, alkaline earth metal halogenapatite phosphors mainly activated by transition metal elements such as Mn, alkaline earth halosilicate phosphors, alkaline earths Metal silicate phosphor, alkaline earth metal borate halogen phosphor, alkaline earth metal aluminate phosphor, alkaline earth metal silicate, alkaline earth metal sulfide, alkaline earth metal thiogallate, alkaline earth metal Rare earth aluminate, rare earth silicate or E mainly activated by lanthanoid elements such as silicon nitride, germanate, or Ce It is preferably at least one selected from organic and organic complexes mainly activated by a lanthanoid element such as u. Preferably, it is a rare earth aluminate phosphor mainly activated by a lanthanoid element such as Ce, and the body color is yellow, Y ₃ Al ₅ O ₁₂ : Ce, (Y _0.8 Gd _0.2 ) ₃ Al ₅ O ₁₂ : Ce, Y ₃ (Al _0.8 Ga _0.2 ) ₅ O ₁₂ : Ce, (Y, Gd) ₃ YAG fluorescence represented by the composition formula of (Al, Ga) ₅ O ₁₂ Is the body. Further, there are Tb ₃ Al ₅ O ₁₂ : Ce, Lu ₃ Al ₅ O ₁₂ : Ce, etc. in which a part or all of Y is substituted with Tb, Lu, or the like.

  Furthermore, phosphors other than the above phosphors and having the same performance, function, and effect can be used.

Table 1 below gives specific examples of the wavelength conversion member. Table 1 shows wavelength conversion members that are excited mainly by blue-based emission wavelengths as light-emitting elements.
(Table 1)

(Light emitting element)
The light emitting element is a light source for irradiating the wavelength conversion member with light to obtain a desired emission color, and has a structure in which positive and negative electrodes are formed on the same surface side, or a structure in which positive and negative electrodes are formed on different surfaces and growth. Semiconductor elements having various structures such as a structure in which a substrate different from the substrate is attached can be used.

The wavelength of the light emitting element can be selected from any wavelength according to the excitation wavelength of the wavelength conversion member to be used. Particularly it is preferable to use short wavelengths the wavelength conversion member can be excited efficiently, as such a light emitting element, a nitride semiconductor _{(In X Al Y Ga 1-} X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is preferable. The composition, emission color, size, number, and the like of the light emitting element to be used can be appropriately selected according to the purpose.

  The light emitting device according to the present invention can be a light emitting device in which a chromatic color is not visually recognized when the light is turned off, and can also be used for various display devices, lighting fixtures, and the like.

DESCRIPTION OF SYMBOLS 100 ... Light-emitting device 101 ... Board | substrate 102 ... Conductive member 103 ... Light emitting element 104 ... Sealing member 105 ... Translucent member 105a ... Inner surface 105b of translucent member ..Outer surface 106 of translucent member ... Mark 107 ... Protection element X ... Hollow part

Claims (4)

A substrate,
A light-emitting element placed on the substrate;
Having a wavelength conversion member whose body color is a chromatic color, and a sealing member covering the light emitting element;
A translucent member bonded onto the substrate and enclosing the sealing member through a hollow portion;
Have
The light-transmitting member is characterized in that two or more light-transmitting members are stacked, and a body color achromatic member of the wavelength conversion member is sandwiched therebetween.   The light emitting device according to claim 1, wherein the sealing member has an outer surface similar in shape to the inner surface of the translucent member.   The light-emitting device according to claim 1, wherein a distance between an outer surface of the sealing member and an inner surface of the translucent member is substantially equal over the entire circumference. 4. The light emitting device according to claim 1, wherein the achromatic member includes at least one of SiO ₂ and Al ₂ O ₃ .

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