阅读说明：本技术 发光二极管封装结构及封装方法 (Light emitting diode packaging structure and packaging method ) 是由 陈雨叁 刘莹莹 王艳刚 于 2018-06-01 设计创作，主要内容包括：本申请涉及发光二极管领域,公开了一种发光二极管封装结构及封装方法。该封装结构包括第一波长转换层,第二波长转换层和第三光学层；第一波长转换层位于第二波长转换层和发光二极管之间；第二波长转换层远离第一波长转换层的一侧设置有第三光学层,第三光学层包括导光层和/或者第三波长转换层；其中,第一波长转换层用于将发光二极管发出的光转换为第一波长的光,第二波长转换层用于将发光二极管发出的光转换为第二波长的光,第一波长与第二波长不同,第三波长转换层用于将发光二极管发出的光转换为第三波长的光。通过上述方式,可以高效的提高封装后的发光二极管显色指数的同时保证可靠性。(The application relates to the field of light emitting diodes and discloses a light emitting diode packaging structure and a packaging method. The packaging structure comprises a first wavelength conversion layer, a second wavelength conversion layer and a third optical layer; the first wavelength conversion layer is positioned between the second wavelength conversion layer and the light emitting diode; a third optical layer is arranged on one side, away from the first wavelength conversion layer, of the second wavelength conversion layer, and comprises a light guide layer and/or a third wavelength conversion layer; the first wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a first wavelength, the second wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a second wavelength, the first wavelength is different from the second wavelength, and the third wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a third wavelength. By the method, the reliability of the packaged light-emitting diode is guaranteed while the color rendering index of the packaged light-emitting diode is efficiently improved.)

1. The packaging structure of the light emitting diode is characterized by comprising a first wavelength conversion layer, a second wavelength conversion layer and a third optical layer;

The first wavelength conversion layer is positioned between the second wavelength conversion layer and the light emitting diode; the third optical layer is arranged on one side, away from the first wavelength conversion layer, of the second wavelength conversion layer and comprises a light guide layer and/or a third wavelength conversion layer;

The first wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a first wavelength, the second wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a second wavelength, the first wavelength is different from the second wavelength, and the third wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a third wavelength.

2. The package structure of claim 1, wherein a thermal conductivity of the first wavelength converting layer and/or the third optical layer is greater than a thermal conductivity of the second wavelength converting layer.

3. The package structure of claim 1, wherein the first wavelength conversion layer and/or the third wavelength conversion layer is at least one of a fluorescent ceramic or a fluorescent glass.

4. The package structure of claim 1, wherein the second wavelength conversion layer is at least one of a fluorescent ceramic, a fluorescent glass, a silica gel phosphor layer, a resin phosphor layer, and a quantum dot film.

5. the package structure according to claim 4, wherein the phosphor particle size in the resin phosphor layer and/or the silica gel phosphor layer is greater than 0 and less than or equal to 10 μm.

6. The package structure of claim 4, wherein the thickness of the silica gel phosphor layer and/or the resin phosphor layer is greater than 0 and less than or equal to 50 microns.

7. the package structure according to claim 4, wherein a ratio of phosphor to resin or silica gel in the resin phosphor layer and/or the silica gel phosphor layer is 1: 1 to 1: 10.

8. The package structure of claim 1, wherein the first wavelength is less than the second wavelength.

9. A light emitting diode packaging method is characterized by comprising the following steps:

Sequentially laminating and stacking a first wavelength conversion layer, a second wavelength conversion layer and a third optical layer on the light emitting diode; or, the first wavelength conversion layer, the second wavelength conversion layer and the third optical layer are sequentially laminated and superposed, and then are laminated and arranged on the light emitting diode, and the first wavelength conversion layer is close to the light emitting diode;

The attaching mode adopts colorless transparent optical glue for attaching;

The third optical layer comprises a light guide layer and/or a third wavelength conversion layer;

The first and third wavelength converting layers comprise at least one of a fluorescent ceramic or a fluorescent glass;

The light guide layer comprises at least one of transparent ceramic or glass;

The second wavelength conversion layer comprises at least one of fluorescent ceramic, fluorescent glass, a silica gel fluorescent layer, a resin fluorescent layer and a quantum dot film.

10. The method of packaging of claim 9, further comprising at least one of:

The preparation of the silica gel fluorescent layer or the resin fluorescent layer comprises the following steps: mixing silica gel or resin with fluorescent powder, then carrying out dispensing or blade coating, and curing to form the silica gel fluorescent layer or the resin fluorescent layer;

The preparation of the fluorescent glass comprises the following steps: mixing fluorescent powder, glass powder and an organic carrier, then carrying out dispensing or blade coating, and then carrying out melt molding to form the fluorescent glass;

the preparation of the fluorescent ceramic comprises the following steps: and cutting and processing the fluorescent ceramic into a flake shape.

Technical Field

The present disclosure relates to the field of light emitting diodes, and more particularly, to a light emitting diode package structure and a light emitting diode package method.

Background

at present, the light emitting diode is widely used as an energy-saving and environment-friendly light source to replace the traditional light source in various indoor and outdoor places (such as home indoor lighting, market decorative lighting, stage lighting, outdoor street lamps, square lighting lamps, advertisement display boards, building exterior wall decorative lighting, traffic lights and the like). In the field of white light emitting diode illumination, people continuously pursue high luminous efficiency and high brightness so as to achieve the highest efficiency of energy conversion and benefit improvement.

in the development process, the application requirements of high power and high brightness are more and more, and the requirements on the packaging process and materials of the high power light emitting diode are gradually increased along with the continuous improvement of the brightness of the high power light emitting diode. The high-power light-emitting diode can adopt fluorescent ceramic to replace the encapsulation of a silica gel fluorescent layer or a resin fluorescent layer (mixing fluorescent powder and adhesive). Compared with an organic packaging silica gel fluorescent layer or a resin fluorescent layer, the fluorescent ceramic has better heat dissipation and heat resistance, but lower conversion efficiency. The light emitting diode packaged by the fluorescent ceramic has better reliability, but still has the problem of lower color rendering index.

In order to solve the problem, the prior art proposes a package structure formed by bonding red and yellow double-layer fluorescent ceramics, wherein after being excited by blue light emitted by a light emitting diode, the yellow fluorescent ceramics generates yellow light, and the red fluorescent ceramics generates red light, which is mixed with the blue light not excited by the fluorescent ceramics to form white light. The red light in the double-layer fluorescent ceramic packaged light-emitting diode can supplement the spectrum missing part, so that the color rendering index is improved, but the conversion efficiency of the fluorescent ceramic is low and is not easy to regulate and control, so that the light-emitting effect is not ideal.

Disclosure of Invention

The technical problem mainly solved by the application is to provide a light emitting diode packaging structure and a packaging method, which can solve the problem of low color rendering index of a packaged light emitting diode and ensure reliability.

In order to solve the technical problem, the application adopts a technical scheme that: providing a light emitting diode packaging structure, wherein the packaging structure comprises a first wavelength conversion layer, a second wavelength conversion layer and a third optical layer; the first wavelength conversion layer is positioned between the second wavelength conversion layer and the light emitting diode; a third optical layer is arranged on one side, away from the first wavelength conversion layer, of the second wavelength conversion layer, and comprises a light guide layer and/or a third wavelength conversion layer; the first wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a first wavelength, the second wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a second wavelength, the first wavelength is different from the second wavelength, and the third wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a third wavelength.

In order to solve the above technical problem, another technical solution adopted by the present application is: sequentially laminating and stacking a first wavelength conversion layer, a second wavelength conversion layer and a third optical layer on the light emitting diode; or, first, laminating and stacking a first wavelength conversion layer, a second wavelength conversion layer and a third optical layer in sequence, and then laminating and arranging the first wavelength conversion layer on the light-emitting diode, wherein the first wavelength conversion layer is close to the light-emitting diode; the attaching mode adopts colorless transparent optical glue for attaching; the third optical layer comprises a light guide layer and/or a third wavelength conversion layer; the first and third wavelength converting layers comprise at least one of a fluorescent ceramic or a fluorescent glass; the light guide layer comprises at least one of transparent ceramic or glass; the second wavelength conversion layer comprises at least one of fluorescent ceramic, fluorescent glass, a silica gel fluorescent layer, a resin fluorescent layer and a quantum dot film.

The beneficial effect of this application does: in contrast to the prior art, the present application provides a light emitting diode package structure, which includes a first wavelength conversion layer, a second wavelength conversion layer, and a third optical layer; the first wavelength conversion layer is positioned between the second wavelength conversion layer and the light emitting diode; a third optical layer is arranged on one side, away from the first wavelength conversion layer, of the second wavelength conversion layer, and comprises a light guide layer and/or a third wavelength conversion layer; the first wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a first wavelength, the second wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a second wavelength, the first wavelength is different from the second wavelength, and the third wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a third wavelength. The light with the second wavelength different from the first wavelength and emitted by the second wavelength conversion layer can make up for the missing part in the spectrum, and the color rendering index of the packaged light-emitting diode is improved. Meanwhile, the third optical layer can adjust the uniformity of surface light emission, can realize the isolation of the first wavelength conversion layer and the second wavelength conversion layer from external environments such as air and the like, can avoid the deterioration and failure of the first wavelength conversion layer and/or the second wavelength conversion layer at higher temperature, improves the reliability of the light emitting diode, and particularly ensures the reliability under the conditions of higher power and temperature.

Drawings

Fig. 1 is a schematic structural diagram of a first embodiment of a light emitting diode package structure according to the present application;

FIG. 2 is a schematic structural diagram of a second embodiment of the light emitting diode package structure of the present application;

FIG. 3 is a schematic structural diagram of a third embodiment of the light emitting diode package structure of the present application;

FIG. 4 is a schematic structural diagram of a fourth embodiment of the light emitting diode package structure of the present application;

Fig. 5 is a schematic structural diagram of a fifth embodiment of the light emitting diode package structure of the present application;

Fig. 6 is a schematic structural diagram of a sixth embodiment of a light emitting diode package structure according to the present application;

FIG. 7 is a schematic flow chart diagram illustrating an embodiment of a method for packaging a light emitting diode according to the present application;

FIG. 8 is a schematic flow chart diagram illustrating another embodiment of a method for packaging a light emitting diode according to the present application;

FIG. 9 is a schematic diagram illustrating the effect of a prior art LED packaging scheme;

Fig. 10 is a schematic diagram illustrating an effect of an embodiment of a packaging scheme of a light emitting diode according to the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the embodiments described below in the present application are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Non-conflicting ones of the following embodiments may be combined with each other.

Fig. 1 is a schematic structural diagram of a first embodiment of a light emitting diode package structure according to the present application.

Referring to fig. 1, 101 is a light emitting diode, 102 is a first wavelength conversion layer, 103 is a silica gel phosphor layer or a resin phosphor layer, and 104 is a third wavelength conversion layer.

The light emitting diode 101 may be a blue light emitting diode 101, may be a single light emitting diode 101, may also be a light emitting diode group formed by a plurality of light emitting diodes 101, and may also be other light emitting diodes 101, which is not limited herein.

The first wavelength conversion layer 102 is located between the silica gel fluorescent layer or resin fluorescent layer 103 and the light emitting diode 101, the first wavelength conversion layer 102 is used for converting light emitted by the light emitting diode 101 into light with a first wavelength, the silica gel fluorescent layer or resin fluorescent layer 103 is used for converting light emitted by the light emitting diode 101 into light with a second wavelength, and the first wavelength is different from the second wavelength.

The light of the first wavelength, the light of the second wavelength and the light emitted by the light emitting diode 101 and not absorbed may be mixed to obtain white light. In general, white light can also be obtained by mixing light of the first wavelength with light emitted by the light emitting diode 101 and not absorbed. Compared with the two white lights, the two white lights are added with the light with the second wavelength, and the missing part in the spectrum can be supplemented, so that the color rendering index is improved. For example, the light emitted by the light emitting diode is blue light, the light of the first wavelength may be yellow light, and the light of the second wavelength may be red light. It is understood that the first wavelength is less than the second wavelength; in this embodiment, the yellow light with the first wavelength has a wavelength smaller than the red light with the second wavelength, and the yellow light in this embodiment cannot excite the red light phosphor, and the red light phosphor is excited by the light with the shorter wavelength emitted by the light emitting diode, specifically, the red light phosphor may be blue light or ultraviolet light, so that the high luminous efficiency of the whole light emitting device is ensured.

The first wavelength conversion layer 102 has a thermal conductivity greater than that of the silica gel fluorescent layer or the resin fluorescent layer 103, and thus heat generated from the silica gel fluorescent layer or the resin fluorescent layer 103 can be diffused through the first wavelength conversion layer 102.

First wavelength-converting layer 102 includes at least one of a fluorescent ceramic or a fluorescent glass, wherein the fluorescent ceramic layer may be a pure phase fluorescent ceramic layer or a complex phase fluorescent ceramic layer.

The silica gel fluorescent layer comprises silica gel and fluorescent powder, wherein the silica gel is used as an adhesive phase to encapsulate the fluorescent powder in the silica gel fluorescent layer. The fluorescent glass layer comprises fluorescent powder and glass, wherein the glass is used as a bonding phase to encapsulate the fluorescent powder. The pure-phase fluorescent ceramic layer is generally composed of pure-phase fluorescent ceramic and does not contain other components serving as bonding phases; such as cerium doped yttrium aluminum garnet pure phase fluorescent ceramics (YAG: Ce). The complex-phase fluorescent ceramic layer comprises fluorescent powder and a ceramic material, wherein the ceramic material is used as a bonding phase to encapsulate the fluorescent powder therein, such as common ceramic material aluminum oxide, undoped yttrium aluminum garnet and the like; in some embodiments, the fluorescent ceramic may be YAG Ce & Al2O3, i.e., a complex phase fluorescent ceramic with cerium-doped yttrium aluminum garnet phosphor and aluminum oxide as the binder phase. It can be understood that the ratio of silica gel to phosphor in the silica gel phosphor layer can be adjusted, the ratio of phosphor to glass frit in the phosphor glass layer can be adjusted, the ratio of yttrium aluminum garnet to cerium in the pure phase ceramic layer can be adjusted, and the ratio of yttrium aluminum garnet, cerium and alumina in the complex phase phosphor ceramic layer can be adjusted. The color temperature can be adjusted according to the specific color temperature requirement, and the detailed description is omitted here.

The silica gel fluorescent layer or the resin fluorescent layer 103 includes fluorescent powder including silica gel, and the resin fluorescent layer includes resin including at least one of cyan fluorescent powder, green fluorescent powder, and red fluorescent powder. The red phosphor may be a red nitride phosphor such as (Sr, Ca) AlSiN3: Eu2 +. It can be understood that, in the fluorescent layer using silica gel or resin as the binder phase, the particle size of the phosphor particles can be larger, and the ratio of the binder phase to the phosphor can be adjusted in a larger range, so that the conversion efficiency of the silica gel fluorescent layer or the resin fluorescent layer is higher than that of the fluorescent ceramic or the fluorescent glass of the same color.

The particle size of the phosphor is greater than 0 and less than or equal to 10 microns. The ratio of the fluorescent powder to the silica gel or the resin is 1: 1 to 1: 10. the thickness of the silica gel fluorescent layer or resin fluorescent layer 103 is greater than 0 and less than or equal to 50 micrometers, and the optimum thickness of the silica gel fluorescent layer or resin fluorescent layer 103 is greater than or equal to 40 micrometers and less than or equal to 50 micrometers.

The third wavelength conversion layer 104 is located on the silica gel fluorescent layer or the resin fluorescent layer 103, and the third wavelength conversion layer 104 is used for converting the light emitted by the light emitting diode 101 into light of a third wavelength, which may be the same as or different from the first wavelength/the second wavelength.

The third wavelength conversion layer 104 has a thermal conductivity greater than that of the gel or resin fluorescent layer 103, and thus heat generated from the gel or resin fluorescent layer 103 can be diffused through the third wavelength conversion layer 104. It will be appreciated that in some embodiments, the first and second wavelength-converting layers are the primary light-emitting regions, and the resulting output light is largely composed of light of the first and second wavelengths, and therefore the first and second wavelength-converting layers generate more heat; in particular the second wavelength converting layer, generates more heat due to its lower conversion efficiency relative to other wavelength converting materials; only a small part of light emitted by the light emitting diode is converted into third-wavelength light through the third wavelength conversion layer, so that the heat generated by the third wavelength conversion layer is smaller than that generated by the second wavelength conversion layer; meanwhile, since the third wavelength is converted into a material having a high thermal conductivity, such as a fluorescent ceramic or a fluorescent glass, the heat generated from the fluorescent silica layer or the fluorescent resin layer 103 can be diffused through the third wavelength conversion layer 104.

Third wavelength-converting layer 104 includes at least one of a fluorescent ceramic or a fluorescent glass, and the structure of third wavelength-converting layer 104 may be the same as that of first wavelength-converting layer 102.

The above embodiments are merely illustrative and do not limit the scope of the present application.

Fig. 2 is a schematic structural diagram of a second embodiment of the light emitting diode package structure of the present application.

The first embodiment and the second embodiment of the light emitting diode package structure of the present application are mainly different in that the second wavelength conversion layer of the first embodiment is a silica gel fluorescent layer or a resin fluorescent layer, and the second wavelength conversion layer of the second embodiment is a quantum dot thin film.

Referring to fig. 2, 201 is a light emitting diode, 202 is a first wavelength conversion layer, 203 is a quantum dot thin film layer, and 204 is a third wavelength conversion layer.

The first wavelength conversion layer 202 is located between the quantum dot thin film layer 203 and the light emitting diode 201, the first wavelength conversion layer 202 is used for converting light emitted by the light emitting diode 201 into light with a first wavelength, the quantum dot thin film layer 203 is used for converting light emitted by the light emitting diode 201 into light with a second wavelength, and the first wavelength is different from the second wavelength.

The first wavelength conversion layer 202 has a thermal conductivity greater than that of the quantum dot thin film layer 203, and thus heat generated from the quantum dot thin film layer 203 can be diffused through the first wavelength conversion layer 202.

The third wavelength conversion layer 204 is located on the quantum dot thin film 203, and the third wavelength conversion layer 204 is used for converting light emitted by the light emitting diode 201 into light of a third wavelength, which may be the same as or different from the first wavelength/the second wavelength.

The third wavelength conversion layer 204 has a thermal conductivity greater than that of the quantum dot thin film 203, and thus heat generated from the quantum dot thin film 203 can be diffused through the third wavelength conversion layer 204.

A quantum dot is a low dimensional semiconductor material whose dimensions in all three dimensions are no greater than twice the exciton bohr radius of its corresponding semiconductor material. Quantum dots are generally spherical or spheroidal, often between 2 and 20 nanometers in diameter. The quantum dots in the quantum dot thin film 203 may be red light quantum dots such as cadmium-based compounds including cadmium selenide and zinc sulfide, cadmium-based compounds including cadmium selenide and cadmium zinc sulfide, and non-cadmium-based compounds including copper indium sulfide and zinc sulfide, and the blue light absorption rate may be reduced by adjusting the quantum dot formulation and thickness.

The above embodiments are merely illustrative and do not limit the scope of the present application.

fig. 3 is a schematic structural diagram of a third embodiment of the light emitting diode package structure of the present application.

Referring to fig. 3, 301 is a light emitting diode, 302 is a first wavelength conversion layer, 303 is a silica gel fluorescent layer or a resin fluorescent layer, and 304 is a light guide layer.

The third embodiment of the light emitting diode package structure of the present application is mainly different from the first embodiment in that the first embodiment is a third wavelength conversion layer located on the silica gel fluorescent layer or the resin fluorescent layer, and the third embodiment is a light guide layer located on the silica gel fluorescent layer or the resin fluorescent layer.

The first wavelength conversion layer 302 is located between the silica gel fluorescent layer or resin fluorescent layer 303 and the light emitting diode 301, the first wavelength conversion layer 302 is used for converting light emitted by the light emitting diode 301 into light with a first wavelength, the silica gel fluorescent layer or resin fluorescent layer 303 is used for converting light emitted by the light emitting diode 301 into light with a second wavelength, and the first wavelength is different from the second wavelength.

304 light guide layer is located on silica gel fluorescent layer or resin fluorescent layer 303, and light guide layer 304 can constitute by sapphire, and light guide layer 304 surface can be done the microstructure, also can plate one deck antireflection coating, improves the extraction efficiency (light-emitting efficiency) of surperficial light, and in addition, light guide layer 304 can play the effect of leaded light, can make light-emitting efficiency increase substantially like this. It is understood that the light guide layer may also be made of other transparent ceramic materials, such as yttrium aluminum garnet (Y3Al5O12), magnesium aluminum spinel (MgAl2O4), aluminum nitride (AlN), aluminum oxynitride (AION), and the like; in other embodiments, the light guiding layer may also be glass. The light guide layer has high heat conductivity coefficient, and meanwhile, no heat generated by wavelength conversion is generated, so that the heat dissipation of the second wavelength conversion layer can be well realized, and the heat stability of the second wavelength conversion layer is improved.

the above embodiments are merely illustrative and do not limit the scope of the present application.

Fig. 4 is a schematic structural diagram of a fourth embodiment of the light emitting diode package structure of the present application.

Referring to fig. 4, 401 is a light emitting diode, 402 is a first wavelength conversion layer, 403 is a quantum dot film, and 404 is a light guide layer.

The main difference between the fourth embodiment and the second embodiment of the light emitting diode package structure of the present application is that the second embodiment is a third wavelength conversion layer located on the quantum dot thin film, and the fourth embodiment is a light guide layer located on the quantum dot thin film.

A first wavelength conversion layer 402 is positioned between the quantum dot thin film 403 and the light emitting diode 401, the first wavelength conversion layer 402 for converting light emitted by the light emitting diode 401 to light of a first wavelength, the quantum dot thin film 403 for converting light emitted by the light emitting diode 401 to light of a second wavelength, the first wavelength being different from the second wavelength.

the light guide layer 404 is located on the quantum dot thin film layer 403.

The above embodiments are merely illustrative and do not limit the scope of the present application.

fig. 5 is a schematic structural diagram of a fifth embodiment of the light emitting diode package structure of the present application.

Referring to fig. 5, 501 is a light emitting diode, 502 is a first wavelength conversion layer, 503 is a silica gel fluorescent layer or a resin fluorescent layer, 504 is a third wavelength conversion layer, and 505 is a light guide layer.

the main difference between the fifth embodiment and the first embodiment of the light emitting diode package structure of the present application is that the fifth embodiment has one more light guiding layer than the first embodiment.

the first wavelength conversion layer 502 is located between the silica gel fluorescent layer or resin fluorescent layer 503 and the light emitting diode 501, the first wavelength conversion layer 502 is used for converting the light emitted by the light emitting diode 501 into the light with the first wavelength, the silica gel fluorescent layer or resin fluorescent layer 503 is used for converting the light emitted by the light emitting diode 501 into the light with the second wavelength, and the first wavelength is different from the second wavelength.

The third wavelength conversion layer 504 is located on the silica gel fluorescent layer or the resin fluorescent layer 503, and the third wavelength conversion layer 504 is used for converting the light emitted by the light emitting diode 501 into light with a third wavelength, which may be the same as or different from the first wavelength/the second wavelength.

The light guiding layer 505 is located above the third wavelength conversion layer 504.

The above embodiments are merely illustrative and do not limit the scope of the present application.

Fig. 6 is a schematic structural diagram of a sixth embodiment of a light emitting diode package structure according to the present application.

Referring to fig. 6, 601 is a light emitting diode, 602 is a first wavelength conversion layer, 603 is a quantum dot film, 604 is a third wavelength conversion layer, and 605 is a light guide layer.

The main difference between the sixth embodiment and the second embodiment of the light emitting diode package structure of the present application is that the sixth embodiment has one more light guiding layer than the second embodiment.

A first wavelength conversion layer 602 is positioned between the quantum dot film 603 and the light emitting diode 601, the first wavelength conversion layer 602 is configured to convert light emitted from the light emitting diode 601 into light of a first wavelength, and the quantum dot film 603 is configured to convert light emitted from the light emitting diode 601 into light of a second wavelength, the first wavelength being different from the second wavelength.

The third wavelength conversion layer 604 is located on the quantum dot thin film 603, and the third wavelength conversion layer 604 is used for converting light emitted by the light emitting diode 601 into light of a third wavelength, which may be the same as or different from the first wavelength/the second wavelength.

The light guiding layer 605 is located on the third wavelength conversion layer 604.

The above embodiments are merely illustrative and do not limit the scope of the present application.

The application provides a light emitting diode packaging structure, which comprises a first wavelength conversion layer, a second wavelength conversion layer and a third optical layer; the first wavelength conversion layer is positioned between the second wavelength conversion layer and the light emitting diode; a third optical layer is arranged on one side, away from the first wavelength conversion layer, of the second wavelength conversion layer, and comprises a light guide layer and/or a third wavelength conversion layer; the first wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a first wavelength, the second wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a second wavelength, the first wavelength is different from the second wavelength, and the third wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a third wavelength. The second wavelength conversion layer comprises at least one of fluorescent ceramic, fluorescent glass, a silica gel fluorescent layer, a resin fluorescent layer and a quantum dot film, and the emitted light with the second wavelength can make up for the missing part in the spectrum and has higher conversion efficiency, so that the color rendering index of the packaged light-emitting diode is improved. Meanwhile, as the heat conductivity coefficients of the first wavelength conversion layer and the third optical layer are larger than that of the second wavelength conversion layer, the heat generated by the second wavelength conversion layer can be diffused out through the first wavelength conversion layer and the third optical layer, and the reliability of the light emitting diode is ensured.

Fig. 7 is a flowchart illustrating an embodiment of a method for packaging a light emitting diode according to the present application.

A first wavelength converting layer is disposed over the light emitting diode S10.

The first wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a first wavelength.

The light emitting diode may be a blue light emitting diode, a single light emitting diode, a light emitting diode group formed by a plurality of light emitting diode groups, or other light emitting diodes, and is not limited specifically herein.

At least one of fluorescent ceramic or fluorescent glass is arranged on the light-emitting diode to form a first wavelength conversion layer, wherein the fluorescent ceramic layer can be a pure-phase fluorescent ceramic layer or a complex-phase fluorescent ceramic layer.

The silica gel fluorescent layer comprises silica gel and fluorescent powder, wherein the silica gel is used as an adhesive phase to encapsulate the fluorescent powder in the silica gel fluorescent layer. The fluorescent glass layer comprises fluorescent powder and glass, wherein the glass is used as a bonding phase to encapsulate the fluorescent powder. The pure-phase fluorescent ceramic layer is generally composed of pure-phase fluorescent ceramic and does not contain other components serving as bonding phases; such as cerium doped yttrium aluminum garnet pure phase fluorescent ceramics (YAG: Ce). The complex-phase fluorescent ceramic layer comprises fluorescent powder and a ceramic material, wherein the ceramic material is used as a bonding phase to encapsulate the fluorescent powder therein, such as common ceramic material aluminum oxide, undoped yttrium aluminum garnet and the like; in some embodiments, the fluorescent ceramic may be YAG Ce & Al2O3, i.e., a complex phase fluorescent ceramic with cerium-doped yttrium aluminum garnet phosphor and aluminum oxide as the binder phase. It can be understood that the ratio of silica gel to phosphor in the silica gel phosphor layer can be adjusted, the ratio of phosphor to glass frit in the phosphor glass layer can be adjusted, the ratio of yttrium aluminum garnet to cerium in the pure phase ceramic layer can be adjusted, and the ratio of yttrium aluminum garnet, cerium and alumina in the complex phase phosphor ceramic layer can be adjusted.

the preparation of the fluorescent glass comprises the following steps: and mixing the fluorescent powder, the glass powder and the organic carrier, then carrying out dispensing or blade coating, and then carrying out melt molding to form the fluorescent glass layer. Wherein the melting temperature is specifically set according to the selected glass powder and the fluorescent powder. Further, the melt molding further comprises a preparation step of a demolding layer, which comprises the following specific steps: firstly, uniformly mixing at least one powder of boron nitride, titanium dioxide and aluminum oxide with an organic carrier to form demolding slurry, coating the slurry on a ceramic substrate to form a demolding layer, and then uniformly scraping the mixed slurry of fluorescent powder, glass powder and the organic carrier on the demolding layer; then, melt molding is performed. The ceramic substrate may be at least one of an aluminum nitride substrate, an aluminum oxide substrate, and the like. The arrangement of the demoulding layer can facilitate the fluorescent glass to be easily separated from the ceramic substrate after the fluorescent glass is melted and formed; the subsequent operation is convenient.

The preparation of the fluorescent ceramic comprises the following steps: and cutting the fluorescent ceramic into a flaky fluorescent ceramic layer. In some embodiments, the finished phosphor ceramic is cut directly to desired thickness and size phosphor ceramic layers as desired. The fluorescent ceramic can be further polished according to the requirement.

The first wavelength conversion layer and the light emitting diode can be bonded together by colorless transparent optical cement or by silica gel.

A second wavelength converting layer is disposed over the first wavelength converting layer S11.

The second wavelength conversion layer is used for converting light emitted by the light emitting diode into light with a second wavelength, the first wavelength is different from the second wavelength, and the second wavelength conversion layer comprises at least one of a silica gel fluorescent layer or a resin fluorescent layer and a quantum dot film.

the light of the first wavelength, the light of the second wavelength and the light emitted by the light emitting diode and not absorbed may be mixed to obtain white light. In general, white light can also be obtained by mixing light of the first wavelength with light emitted by the light emitting diode and not absorbed. Compared with the two white lights, the two white lights are added with the light with the second wavelength, and the missing part in the spectrum can be supplemented, so that the color rendering index is improved. For example, the light emitted by the light emitting diode is blue light, the light of the first wavelength may be yellow light, and the light of the second wavelength may be red light.

Mixing silica gel and fluorescent powder to form a silica gel fluorescent layer, and mixing resin and fluorescent powder to form a resin fluorescent layer, wherein the fluorescent powder comprises at least one of cyan fluorescent powder, green fluorescent powder and red fluorescent powder. The red phosphor may be a red nitride phosphor such as (Sr, Ca) AlSiN3: Eu2 +. The conversion efficiency of the silica gel fluorescent layer or the resin fluorescent layer is higher than that of fluorescent ceramic or fluorescent glass with the same color.

the particle size of the phosphor is larger than 0 and less than or equal to 10 microns; the ratio of the fluorescent powder to the adhesive is 1: 1 to 1: 10; the thickness of the silica gel fluorescent layer or the resin fluorescent layer is larger than 0 and smaller than or equal to 50 micrometers.

the preparation process of the silica gel fluorescent layer or the resin fluorescent layer comprises the steps of uniformly mixing silica gel or resin and fluorescent powder, then placing the mixture in a vacuum environment to remove bubbles, coating the mixture on the surface of the mixture on the poly-terephthalic acid plastic without adhesion enhancement treatment, baking the mixture at 150 ℃ for 5 to 10 minutes, carrying out demolding treatment, and baking the mixture to completely cure the coating. It is understood that in other embodiments, light curing or other curing methods may be used depending on the specific type of the silicone or resin.

The first wavelength conversion layer has a thermal conductivity greater than that of the second wavelength conversion layer, and thus heat generated from the second wavelength conversion layer can be diffused through the first wavelength conversion layer.

And S12, arranging a third optical layer on the side, far away from the first wavelength conversion layer, of the second wavelength conversion layer, wherein the third optical layer comprises a light guide layer and/or a third wavelength conversion layer.

The second wavelength conversion layer may be provided with only the third wavelength conversion layer, or the second wavelength conversion layer may be provided with the third wavelength conversion layer and the light guide layer may be provided on the third wavelength conversion layer, and the light guide layer may be made of sapphire. The third wavelength conversion layer is used for converting the light emitted by the light emitting diode into light with a third wavelength, and the third wavelength may be the same as or different from the first wavelength/the second wavelength.

The third wavelength-converting layer has a thermal conductivity greater than the second wavelength-converting layer.

The third wavelength conversion layer may be prepared in the same manner as the first wavelength conversion layer, and the structure of the third wavelength conversion layer may be the same as the first wavelength conversion layer.

The first wavelength conversion layer and the second wavelength conversion layer can be bonded together by a colorless transparent optical adhesive, or can be bonded by a silicone adhesive, and similarly, the second wavelength conversion layer and the third wavelength conversion layer, the third wavelength conversion layer and the second wavelength conversion layer, the light guide layer and the second wavelength conversion layer, and the third wavelength conversion layer and the light guide layer can be bonded by a colorless transparent optical adhesive or a silicone adhesive.

Fig. 8 is a schematic flow chart of another embodiment of the light emitting diode packaging method of the present application.

S20, arranging a first wavelength conversion layer on the light emitting diode, arranging a second wavelength conversion layer on the first wavelength conversion layer, and arranging a third optical layer on the side of the second wavelength conversion layer far away from the first wavelength conversion layer, wherein the third optical layer comprises a light guide layer and/or a third wavelength conversion layer.

and S21, attaching the three-layer structure on the LED, wherein the first wavelength conversion layer is close to the LED.

It is understood that in other embodiments, the sequence of the operation steps of an embodiment of the light emitting diode packaging method of the present application may be appropriately adjusted according to the need. For example, the bonding method may be to bond at least one of the first wavelength conversion layer, the second wavelength conversion layer, the third wavelength conversion layer, and the light guide layer in sequence, then cut into blocks having the same size as the light emitting diode, and then bond the blocks on the light emitting diode.

Fig. 9 is a schematic view showing an effect of a packaging scheme of a light emitting diode in the prior art, in which a wavelength conversion layer employs silica gel to package phosphor, that is, a silica gel phosphor layer, as shown in fig. 9, a surface flatness of a packaging structure is low, which affects uniformity of light emitted from a surface. Since the light emitted from the light-emitting surface finally includes the light emitted from the unconverted light-emitting diode chip, the light emitted from the first wavelength conversion layer, and the light emitted from the second wavelength conversion layer (in this example, the light emitted from the silica gel fluorescent layer), the light from the three different sources can be sufficiently and uniformly mixed to obtain the light with uniform color and brightness, and the light-emitting surface with poor surface flatness can cause the light paths of the light at different positions to be different, so that the uniformity of the light at different positions is affected.

Fig. 10 is a schematic effect diagram of an embodiment of a packaging scheme of a light emitting diode according to the present application, wherein a third wavelength conversion layer is disposed on the second wavelength conversion layer, in this embodiment, the third wavelength conversion layer employs a fluorescent ceramic layer containing yttrium aluminum garnet and cerium, and the flatness of a light emitting surface of the third wavelength conversion layer is higher than that of the silica gel fluorescent layer in fig. 9, so that the light emitting uniformity of the packaging structure according to the present application is improved. Meanwhile, on one hand, as described above, the heat dissipation rate of the second wavelength conversion layer can be improved by using the third wavelength conversion layer having higher thermal conductivity, such as a fluorescent ceramic, and on the other hand, the third wavelength conversion layer prevents the second wavelength conversion layer from directly contacting with the external environment (such as air), so that the deterioration and failure of the second wavelength conversion layer at higher temperature can be avoided, and particularly, in the embodiment where the red phosphor is encapsulated by using organic substances, such as silica gel and resin, for the second wavelength conversion layer.

The application provides a light emitting diode packaging method, which comprises the steps of sequentially attaching and superposing a first wavelength conversion layer, a second wavelength conversion layer and a third optical layer on a light emitting diode; or, first, laminating and stacking a first wavelength conversion layer, a second wavelength conversion layer and a third optical layer in sequence, and then laminating and arranging the first wavelength conversion layer on the light-emitting diode, wherein the first wavelength conversion layer is close to the light-emitting diode; the attaching mode adopts colorless transparent optical glue for attaching; the third optical layer comprises a light guide layer and/or a third wavelength conversion layer; the first and third wavelength converting layers comprise at least one of a fluorescent ceramic or a fluorescent glass; the light guide layer comprises at least one of transparent ceramic or glass; the second wavelength conversion layer comprises at least one of fluorescent ceramic, fluorescent glass, a silica gel fluorescent layer, a resin fluorescent layer and a quantum dot film. . The light with the second wavelength emitted by the second wavelength conversion layer can make up for the missing part in the spectrum and has higher conversion efficiency, and the color rendering index of the packaged light-emitting diode is improved. Meanwhile, as the heat conductivity coefficients of the first wavelength conversion layer and the third optical layer are larger than that of the second wavelength conversion layer, the heat generated by the second wavelength conversion layer can be diffused out through the first wavelength conversion layer and the third optical layer, and the reliability of the light emitting diode is ensured.

It should be noted that the above-mentioned embodiments are only examples of the present application, and not intended to limit the scope of the present application, and all equivalent structures or equivalent flow transformations made by the contents of the specification and the drawings, such as the combination of technical features between the embodiments, or the direct or indirect application to other related technical fields, are also included in the scope of the present application.