TWI599078B - Wafer-level package light-emitting device with moisture barrier structure - Google Patents

Description

Wafer-level package light-emitting device with moisture barrier structure

The present invention relates to a light-emitting device, and more particularly to a light-emitting device having a moisture barrier structure and applying an LED chip.

LED (Light Emitting Diode) wafers are commonly used to provide illumination, display or indication light sources, and LED chips are typically disposed in a package structure to form a light emitting device, wherein the package structure can include a photoluminescence A material (fluorescent material or light conversion material) to partially convert light (eg, blue light) emitted by the LED wafer to other wavelengths (eg, yellow light), and light of different wavelengths is mixed to form white light. The spectrum characteristics of the photoluminescent materials to be used vary depending on the application.

For example, in current liquid crystal displays, LED light-emitting devices are mostly used as backlight sources, and in this application, if the photo-luminescence material has a narrow half-height width (FWHM) light-emitting spectrum, the color purity of the display can be improved (color Purity), which allows it to have a wider color gamut to provide consumers with a more vivid color experience. On the other hand, in lighting applications, if the LED lighting device uses a photoluminescent material with a narrower emission spectrum (for example, emitting red light), it can effectively improve the color rendering (CRI) of the light and avoid sacrificing excessive light conversion efficiency. Make it high The color-developing illuminating device still has good luminous efficiency as a whole.

Among the existing photoluminescent materials, there are several kinds of spectrums which can provide a narrow half-height width spectrum, such as a fluoride fluorescent material or a quantum dot light-converting material, which attracts the attention of the LED industry. However, these light converting materials are quite sensitive to moisture. For example, a fluoride fluorescent material contains an active element (for example, manganese) which is easily oxidized, and when it is exposed to moisture in the air, it is easily oxidized to form an oxide; these oxides cause the active element to lose the function of light conversion, and thus cannot Provides light of the expected brightness (or expected wavelength). In other words, these fluorescent materials are prone to deteriorating performance due to moisture. Therefore, the industry has also proposed a solution to reduce the impact of moisture on these fluorescent materials.

For example, in the solution of the U.S. Patent No. (U.S. Patent No. 8,057,706 B1), a protective layer can be formed on the surface of the fluoride fluorescent material, which is a manganese-free fluorescent material, thereby reducing water. Gas permeation leads to oxidation of the active element; in a solution of another US patent (Patent No. US 9,120,972 B2), a protective layer is also formed on the surface of the fluoride fluorescent material, the protective layer being a lower concentration Fluorescent material of manganese. Both of these solutions reduce the degradation of the phosphorescent material due to moisture due to the reduced chance of oxidation of the manganese element. However, the above method only reduces the performance degradation caused by moisture of the fluorescent material, and the attenuation cannot be completely avoided. At the same time, each of the fluoride fluorescent material particles is completely coated with a manganese-free (or The protective layer of low concentration manganese is very difficult and will increase the production cost. Furthermore, the presence of the protective layer will also reduce the light conversion efficiency of the fluoride fluorescent material.

In the package structure of the LED lighting device, there are also proposals to improve the operational stability of the light-emitting device by improving the influence of moisture on the fluorescent material. For example, in a solution of the U.S. Patent Application (Patent No. US 2015/0270451), a stent type (PLCC-type) is disclosed. In the illuminating device, the underside and the periphery of the LED chip are covered by the bracket structure, and the illuminating surface of the front surface is easily subjected to moisture penetration. Therefore, the application adds a silicone overlayer to the bracket. The front side of the illuminating device can reduce the layer of fluorescent material that penetrates from the outside to the inside of the illuminating device; in the solution of another US patent application (Patent No. US 2015/0270452), a bracket type illuminating device is also disclosed. The phosphor material is mixed with the silicone rubber to form a blend, and the mixture is disposed in the groove formed by the stent structure, and in the mixture, the silicone rubber accounts for a larger weight percentage relative to the fluorescent material, and more silicone rubber is used. It can increase the ability to block moisture to reduce the impact of fluorescent materials on moisture.

The above solution for blocking moisture from the package structure is directed to the bracket type illuminating device. However, the use of the bracket increases the package size of the LED chip, and a thicker enamel cover layer or more enamel content is used to improve the moisture barrier effect. The overall size of the illuminating device is further increased. Such a solution is disadvantageous for the LED to be applied to light and thin electronic products such as LED backlight sources for mobile devices or televisions. In order to meet the needs of such applications, LED light-emitting devices must have a small size, and in the continuous development of small-sized light-emitting devices, chip-scale package (CSP) light-emitting devices have the most advantages, and are also attracting the most attention. The reduction of the size of the LED package makes the blocking of external moisture more difficult. So far, the existing LED technology still has no good moisture barrier scheme applicable to the CSP illumination device.

Therefore, how to make the CSP LED illuminating device have good moisture barrier ability when using moisture sensitive photoluminescent materials to improve various performances, and still can not increase the CSP LED package size, which is the current LED industry to be solved urgently. The problem.

It is an object of the present invention to provide a light-emitting device having various moisture barrier mechanisms to reduce or prevent moisture in the outside air from affecting the moisture-sensitive photoluminescent material within the light-emitting device. In addition, the moisture barrier mechanism does not cause a substantial increase in the package size of the light-emitting device, so the light-emitting device can still be realized as a wafer-level package.

In an embodiment of the present invention, the light emitting device may include: a blue LED chip; a photoluminescent structure disposed on the blue LED chip and including a first light a light emitting layer and a second photoluminescent layer, wherein the first photoluminescent layer is disposed on the second photoluminescent layer, the first photoluminescent layer comprises a first polymer material and is mixed with the first high One of the molecular materials is a non-moisture sensitive photoluminescent material, and the second photoluminescent layer comprises a second polymeric material and a moisture sensitive photoluminescent material mixed in the second polymeric material And a reflective structure surrounding the blue LED chip and the photoluminescent structure, the reflective structure comprising a third polymer material and one of the third high-division material non-moisture-sensitive optical scattering particles.

In accordance with another embodiment of the present invention, the light emitting device can include: a blue LED chip; a photoluminescent structure disposed on the blue LED chip and including a first light a photoluminescent layer and a second photoluminescent layer, the first photoluminescent layer is coated on the second photoluminescent layer; and a transparent encapsulating structure disposed on the photoluminescent structure; wherein the A photoluminescent layer comprises a first polymer material and a non-moisture sensitive photoluminescent material mixed in the first polymer material, and the second photoluminescent layer comprises a second polymer material and A moisture sensitive photoluminescent material is mixed in the second polymer material, and the transparent package structure comprises a transparent polymer material.

In order to achieve the above object, according to still another embodiment of the present invention, a moisture-shielding layered photoluminescence structure applied to a stent type LED light-emitting device using a moisture-sensitive photoluminescence material, the light-emitting device comprising: a blue LED chip; a package structure comprising a lead frame and a lead frame a reflective body partially covering the lead frame and including a recess, the blue LED chip being disposed in the recess and electrically connected to the first electrode and the second electrode of the lead frame; a photoluminescent structure disposed above the blue LED chip and in the recess, and including a first photoluminescent layer and a second photoluminescent layer, the first photoluminescent layer being disposed on the second light The first photoluminescent layer comprises a first polymer material and a non-moisture sensitive photoluminescent material mixed in the first polymer material, and the second photoluminescent layer comprises a second polymer material and a moisture sensitive photoluminescent material mixed in the second polymer material.

Therefore, the light-emitting device proposed by the present invention can provide at least the following beneficial technical effects: the first photoluminescent layer can block the passage of moisture, so that the moisture does not easily penetrate the moisture-sensitive light of the second photoluminescent layer. The luminescent material; the reflective structure, the transparent package structure or the package structure can also block the passage of moisture, and reduce the influence of moisture on the moisture-sensitive photoluminescent material. In this way, the moisture-sensitive photoluminescent material is shielded by the structure having the moisture barrier property, and the photoluminescent material can be reduced in the performance degradation caused by the environmental moisture.

In addition, in the first photoluminescent layer, in addition to the first polymer material can hinder the passage of moisture, the non-moisture-sensitive photoluminescent material can further hinder the external environment moisture in addition to providing the function of the original light conversion. Penetration, so the first polymer material does not need a large thickness to make the first photoluminescent layer have a good ability to block moisture as a whole, and achieve the purpose of protecting the inner layer moisture sensitive photoluminescent material. In this way, under the mechanism of moisture blocking, the overall size of the illuminating device can still meet the requirements of miniaturization of the package size.

In another aspect, the light emitting device may further comprise a moisture absorbing layer, a moisture absorbing material and/or a moisture blocking structure to have better moisture barrier or moisture removal capability, so that moisture is more difficult to penetrate from the external environment to moisture. Sensitive photoluminescent material.

The above objects, technical features and advantages will be more apparent from the following description.

1, 2, 3, 4, 5‧‧‧ illuminating devices

10, 10'‧‧‧Blue LED chip, LED chip

11‧‧‧ upper surface

12‧‧‧ Lower surface

13‧‧‧Facade

14‧‧‧Electrode group

20, 20'‧‧‧Photoluminescent structure, PL structure

201’‧‧‧ top

202’‧‧‧

203’‧‧‧ side

201‧‧‧ top surface

202‧‧‧ bottom

203‧‧‧ side

21‧‧‧First photoluminescent layer, first PL layer

211‧‧‧First polymer material

212‧‧‧ Non-moisture sensitive photoluminescent materials, non-moisture sensitive materials

22‧‧‧Second photoluminescent layer, second PL layer

221‧‧‧Second polymer material

222‧‧‧ Moisture sensitive photoluminescent materials, moisture sensitive materials

23‧‧‧ Third photoluminescent layer, third PL layer

231‧‧‧ Third polymer material

232‧‧‧ Non-moisture sensitive photoluminescent materials, moisture sensitive materials

24‧‧‧Moisture absorbing layer

241‧‧‧Transparent polymer materials

242‧‧‧Hydrautical materials

30‧‧‧Reflective structure

31‧‧‧ Third polymer material

32‧‧‧Optical scattering particles

40‧‧‧Substrate

50‧‧‧Light transparent moisture barrier

60‧‧‧Moisture barrier structure

61‧‧‧ fourth polymer material

70‧‧‧Transparent package structure

71‧‧‧Transparent polymer materials

80‧‧‧Package structure

81‧‧‧ lead frame

811‧‧‧First electrode

812‧‧‧second electrode

82‧‧‧ reflector

821‧‧‧ Groove

83‧‧‧Transparent polymer materials

1A and 1B are cross-sectional views showing various aspects of a light-emitting device according to a first preferred embodiment of the present invention; and FIGS. 2A to 2D are light-emitting devices according to a second preferred embodiment of the present invention; 3 is a schematic cross-sectional view of a light emitting device according to a third preferred embodiment of the present invention; and FIGS. 4A and 4B are light emitting devices according to a fourth preferred embodiment of the present invention; FIG. 5A and FIG. 5B are schematic cross-sectional views showing various types of light-emitting devices according to a fifth preferred embodiment of the present invention.

Please refer to FIG. 1A, which is a schematic diagram of a light-emitting device 1 according to a first preferred embodiment of the present invention. The illuminating device 1 can include a blue LED chip 10, a photoluminescent structure 20, and a reflective structure 30. The technical contents of each component will be described below.

The blue LED chip (hereinafter referred to as LED chip) 10 may be a flip chip type LED chip including an upper surface 11, a lower surface 12, a vertical surface 13 and an electrode group 14. The upper surface 11 and the lower surface 12 are oppositely and oppositely disposed, and the elevation surface 13 is formed between the upper surface 11 and the lower surface 12 and connects the upper surface 11 and the lower surface 12, in other words, the elevation 13 along the upper surface 11 The rim is formed with the edge of the lower surface 12, so the façade 13 is annular (e.g., a rectangular ring) with respect to the upper surface 11 and the lower surface 12.

The electrode group 14 is disposed on the lower surface 12 and may have more than two electrodes. Electrical energy (not shown) may be supplied to the LED wafer 10 through the electrode assembly 14 to cause the LED wafer 10 to emit light in accordance with the wavelength range of the blue light; most of the light may be emitted from the upper surface 11 and the elevation 13.

The photoluminescent (PL) structure 20, after being irradiated by the blue light emitted by the LED chip 10, can absorb part of the blue light to generate light of different wavelengths (for example, red light and green light), and then the blue light and When other light rays are mixed, they can form light of a desired color (for example, white light).

Appearance, the photoluminescent structure (hereinafter referred to as PL structure) 20 includes a top surface 201, a bottom surface 202 and a side surface 203. The top surface 201 and the bottom surface 202 are opposite and oppositely disposed, and the side surface 203 is formed on the top surface 201 and the bottom surface. Between 202, and connecting the top surface 201 and the bottom surface 202, in other words, the side surface 203 is annular (e.g., a rectangular ring) with respect to the top surface 201 and the bottom surface 202.

Positionally, the PL structure 20 is disposed on the LED wafer 10, that is, the bottom surface 202 of the PL structure 20 is on the upper surface 11 of the LED wafer 10, and the bottom surface 202 can be overlaid on the upper surface 11. In other possible aspects, the bottom surface 202 is spaced from the upper surface 11 to indicate that other structures or materials (not shown) may be disposed between the PL structure 20 and the LED wafer 10. In addition, the bottom surface 202 may be slightly larger than the upper surface 11, but is not limited thereto. Structurally, the PL structure 20 includes a first photoluminescent layer (hereinafter simply It is referred to as a first PL layer 21 and a second photoluminescent layer (hereinafter simply referred to as a second PL layer) 22; the first PL layer 21 is disposed on the second PL layer 22, and the two may be stacked, or two They may be spaced apart for other structures or materials to be placed therebetween.

The first PL layer 21 may include a first polymer material 211 and a non-moisture sensitive photoluminescent material (hereinafter referred to as non-humidity sensitive material) 212. The non-humidity sensitive material 212 may be uniformly mixed and fixed to the first layer. In the polymer material 211. The non-humidity sensitive material 212 can generate light of other wavelengths (eg, green light) after being exposed to blue light. The non-humidity sensitive material 212 may not contain an active element which is easily oxidized, so that it is less likely to form an oxide upon contact with moisture (the formation of an oxide may cause the generation of light or the wavelength of the generated light does not conform to the desired wavelength). In other words, the non-humidity sensitive material 212 can also generate light of a desired wavelength after being exposed to moisture, and is not susceptible to moisture to change its light conversion characteristics. The non-humidity sensitive material 212 may include, but is not limited to, an inorganic fluorescent material or an oxynitride green fluorescent material, and the oxynitride green fluorescent material is more β-SiAlON.

In addition to being less susceptible to moisture, the non-humidity sensitive material 212 can also impede the passage of moisture. The following table shows the measurement data of the water vapor transmission rate of the film. The silicone film A consists only of tannin gel, and the measured water vapor permeability is 10.51 (g/m ² /day); the silicone film B except the tannin extract In addition, a 60% by weight non-moisture sensitive fluorescent material is included to reduce the water vapor transmission rate to 8.31 (g/m ² /day). Therefore, when the first polymer material 211 contains the non-moisture sensitive material 212, the water vapor permeability of the first PL layer 21 can be further reduced.

When the weight percentage of the non-humidity sensitive material 212 in the first PL layer 21 is larger, that is, the higher the stack density, the effect of hindering moisture is better. Therefore, preferably, the weight percentage of the non-humidity sensitive material 212 in the first PL layer 21 is not less than 50%, not less than 60% or not less than 70%. In order to have a higher packing density of the non-humidity sensitive material 212, the median value (D50) of the particle diameter of the non-humidity sensitive material 212 is preferably no greater than 30 microns, no greater than 20 microns, or no greater than 10 microns.

The first polymer material 211 may be used in addition to the non-humidity sensitive material 212 that hinders the passage of moisture. The first polymer material 211 can be selected to have a lower water vapor transmission rate (WVTR), for example, not more than 10 g/m ² /day, to increase the effectiveness of blocking moisture. The first polymer material 211 may include, but is not limited to, a resin material or a silicone material.

In summary, the first polymer material 211 and the non-humidity material 212 of the first PL layer 21 can block the passage of moisture, so that the first PL layer 21 as a whole reduces the influence of moisture on the second PL layer 22 underneath. .

The second PL layer 22 may include a second polymer material 221 and a moisture sensitive photoluminescent material (hereinafter referred to as a humidity sensitive material) 222. The moisture sensitive material 222 may be uniformly mixed and fixed to the second polymer material. 221. The moisture sensitive material 222 can generate light of other wavelengths (for example, red light) after being irradiated with blue light, and preferably has a narrower spectrum of light emission.

The moisture sensitive material 222 is a fluorescent material containing a oxidizable active activator or a quantum dot photoluminescent material, and moisture easily causes the moisture sensitive material 222 to be difficult to generate light or generated. The wavelength of the light does not match the required. However, the first PL layer 21 may hinder the passage of moisture, reducing the possibility of moisture penetrating into the moisture sensitive material 222. Therefore, the moisture sensitive material 222 The service life can be longer. The second polymer material 221 can also be selected to have a low water vapor permeability (for example, a resin having a low water vapor permeability or a silicone material), further reducing the possibility of moisture penetrating into the moisture sensitive material 222.

In this embodiment, the moisture sensitive material 222 may comprise a fluoride red fluorescent material, and the fluoride red fluorescent material comprises at least one of: (A) A ₂ [MF ₆ ]: M ⁴⁺ , wherein A Selected from Li, Na, K, Rb, Cs, NH ₄ and combinations thereof, M is selected from the group consisting of Ge, Si, Sn, Ti, Zr, and combinations thereof; (B) E ₂ [MF ₆ ]: M ⁴⁺ , wherein E Selected from Mg, Ca, Sr, Ba, Zn, and combinations thereof, M is selected from the group consisting of Ge, Si, Sn, Ti, Zr, and combinations thereof; (C) Ba _0.65 Zr _0.35 F _2.70 : M ⁴⁺ ; or (D) A ₃ [ZrF ₇ ]: M ⁴⁺ , wherein A is selected from the group consisting of Li, Na, K, Rb, Cs, NH ₄ and combinations thereof.

The formation of the first PL layer 21 and the second PL layer 22 can be achieved by spraying, dispensing, printing, molding, or the like. Taking the first PL layer 21 as an example, the uncured first polymer material 211 and the non-humidity sensitive material 212 are first mixed, and then deposited on a substrate or the like (not shown) by the above method; After the polymer material 211 is cured and the substrate is removed, the first PL layer 21 is formed.

Although the first PL layer 21 can be formed by spraying, dispensing, printing, molding, etc., it is difficult to form the non-moisture sensitive material 212 of the higher density stack, so that the moisture barrier is formed. The effect is poor. Preferably, the formation of the first PL layer 21 and the second PL layer 22 can be achieved by the method disclosed in the previously proposed US Patent Application Publication No. US 2010/0119839 (corresponding to Taiwan Patent No. I508331). This method allows the material to be uniformly deposited, so that the first PL layer 21 and the second PL layer 22 can have a uniform thickness. Further, the method can cause the material to be densely deposited, so the non-humidity sensitive material 212 of the first PL layer 21 can be not less than 50%, not less than 60%, or not less than 70% by weight.

It is to be noted that the first PL layer 21 and the second PL layer 22 are separately formed and are not integrally formed to prevent the moisture sensitive material 222 of the second PL layer 22 from being mixed into the first polymer material 211 of the first PL layer 21.

The reflective structure 30 surrounds the LED chip 10 and the PL structure 20 for reflecting the light generated by the LED chip 10 and the PL structure 20 to form a light reflecting layer; in other words, the light is mainly emitted upward from the top surface 201 of the PL structure 20. The reflective structure 30 can cover and directly contact the façade 13 of the LED wafer 10 and the side 203 of the PL structure 20.

The reflective structure 30 can also block the passage of moisture to reduce the likelihood of moisture contacting the moisture sensitive material 222. Therefore, a third polymer material 31 included in the reflective structure 30 and one of the optical diffusing particles 32 mixed with the third high-part material 31 may preferably be configured as follows: The third polymer material 31 may be optionally provided. Those having a lower moisture permeability (for example, not more than 10 g/m ² /day) may include, for example, a resin material or a silicone material. The weight percentage of the optically scattering particles 32 in the reflective structure 30 is not less than 30%. The optically scattering fine particles 32 may specifically be titanium oxide (TiO ₂ ), boron nitride (BN), cerium oxide (SiO ₂ ) or aluminum oxide (Al ₂ O ₃ ).

In fabrication, the reflective structure 30 can be formed by methods such as dispensing, printing, or molding. For example, the optical scattering particles 32 may be first mixed with the third high-division material 31 to fabricate the manufacturing material of the reflective structure 30, and then the manufacturing material of the reflective structure 30 may be surrounded by the wafer by means of dispensing, printing or molding. 10 and the periphery of the PL structure 20 are cured to form the reflective structure 30.

Please refer to FIG. 1B, which is another schematic diagram of a light-emitting device 1 according to a first preferred embodiment of the present invention. Optionally, the light emitting device 1 further includes a substrate 40, and the LED chip 10 and the reflective structure 30 are disposed on the substrate 40. The substrate 40 can include, but is not limited to: a ceramic substrate, a glass A glass substrate, a printed circuit board or a metal core PCB. In fabrication, the light-emitting device 1 shown in FIG. 1A can be bonded to the substrate 40 using eutectic soldering or reflow soldering.

Thereby, the light-emitting device 1 can have at least the following technical features:

1. The blue light generated by the LED chip 10 causes the first PL layer 21 and the second PL layer 22 to generate light of different wavelengths (for example, green light and red light), and then the light is mixed to form a specific spectrum of light. (eg white light).

2. The first PL layer 21 can block the moisture permeation from the upper portion of the second PL layer 22, in addition to generating light. The reflective structure 30 can block moisture from its surroundings, and the LED wafer 10 can also block the passage of moisture from beneath it. In other words, the three structures of the first PL layer 21, the reflective structure 30, and the LED wafer 10 encapsulate the second PL layer 22 therein to form a protection for the moisture sensitive material 222 of the second PL layer 22. The first to third polymer materials 211, 221, 31 may each have a low water vapor permeability to increase the protection of the moisture sensitive material 222.

3. The first PL layer 21 does not rely solely on the first polymer material 211 to block moisture, and the non-humidity material 212 can also block moisture, so the first polymer material 211 does not need a large thickness. In addition, the non-humidity sensitive material 212 may have a smaller particle size or a more dense distribution, such that when the weight percentage of the non-humidity sensitive material 212 is increased, the thickness of the first polymer material 211 does not increase proportionally, for example only Increased slightly. Thus, the first PL layer 21 can be made to have a low water vapor permeability while maintaining the first PL layer 21 at a similar thickness. Therefore, the overall size of the illuminating device 1 under the mechanism of retaining moisture can still meet the requirements of wafer level packaging.

The above is a description of the technical content of the illuminating device 1. Next, the technical contents according to other embodiments of the present invention will be described, and the technical contents of the respective embodiments should be referred to each other, and the same portions will be omitted or simplified. Furthermore, the technical content of the embodiments should be applicable to each other.

Please refer to FIGS. 2A to 2D, which are schematic views of various types of the light-emitting device 2 according to the second preferred embodiment of the present invention. As shown in FIG. 2A, the light-emitting device 2 further includes a light-transparent moisture barrier layer 50 in addition to the LED wafer 10, the PL structure 20, and the reflective structure 30.

Specifically, the light transparent moisture barrier layer 50 is disposed on the PL structure 20 and may be further extended to the reflective structure 30. Alternatively, the light transparent moisture barrier layer 50 is disposed only on the PL structure 20 and is surrounded by the reflective structure 30 (not shown). The light transparent moisture barrier layer 50 does not block the passage of light, but can block moisture from passing therethrough, making it more difficult for moisture to penetrate to the moisture sensitive material 222. The light transparent moisture barrier layer 50 may include, but is not limited to, a transparent inorganic layer (such as glass) or a low water vapor permeability polymer layer (such as a polymer). In the production, the light-transparent moisture barrier layer 50 can be attached to the light-emitting device 1 to form the light-emitting device 2 as shown in Fig. 2A.

As shown in FIG. 2B, the PL structure 20 of the light-emitting device 2 may further include a transparent getter layer 24 interposed between the first PL layer 21 and the second PL layer 22. The majority of the moisture is blocked by the light transparent moisture barrier layer 50 and the first PL layer 21, but a little moisture may still pass through the moisture barrier structures, and the moisture may be absorbed by the moisture absorbing layer 24 at this time. The chance of the moisture sensitive material 222 of the second PL layer 22 being affected by moisture is further reduced.

The moisture absorbing layer 24 can be implemented as a transparent polymer material 241 and a getter material 242 mixed in the transparent polymer material. The transparent polymer material 241 can be, for example, a resin, a silicone rubber, a rubber or a An optically transparent material such as plastic, and preferably heat resistant without deterioration; the moisture absorbing material 242 may comprise a plurality of nanoparticles, for example, one or a combination of the following: zeolite (zeolite), zeolitic (zeolitic) Clays), calcium oxide (CaO), barium oxide (BaO), alumina, calcium, barium, titanium, metal alloys, water absorbing oxides, activated carbon, absorbent organic or Inorganic material Absorptive organic or inorganic materials, etc.; the particle size of the nanoparticles may be less than a quarter of the wavelength of visible light, such as less than 200 nanometers or less. In the production, for example, the moisture absorbing layer 24 can be formed by a method such as dispensing, printing, molding, or spray coating.

The moisture absorbing layer 24 can also be formed as a particle-free, that is, the moisture absorbing layer 24 can be cured by a transparent liquid hygroscopic material. The technical content of such a moisture absorbing layer 24 can be found at least in the U.S. Patent Application Publication No. US 2013/0181163 A1.

As shown in FIG. 2C, the first PL layer 21 and/or the second PL layer 22 of the PL structure 20 of the light-emitting device 2 may directly comprise a moisture absorbing material 242, that is, the moisture absorbing material 242 is directly mixed with A polymer material 211 and/or a second polymer material 221 . As shown in FIG. 2D, the reflective structure 30 can also include a moisture absorbing material 242, that is, the moisture absorbing material 242 is mixed in the third polymer material 31. Thus, the moisture entering the first polymer material 211, the second polymer material 221, and/or the third polymer material 31 can be absorbed by the moisture absorbing material 242 to be more difficult to contact the moisture sensitive material 222.

In summary, the illuminating device 2 transmits the light transparent moisture barrier layer 50, the moisture absorbing layer 24 or the moisture absorbing material 242 to further prevent moisture from contacting the moisture sensitive material 222.

Please refer to FIG. 3, which is a schematic diagram of a light-emitting device 3 according to a third preferred embodiment of the present invention. The light-emitting device 3 further includes a moisture blocking structure 60 in addition to the LED wafer 10, the PL structure 20, the reflective structure 30, and the light-transparent moisture barrier layer 50.

Specifically, although a low water vapor permeability polymer material may be selected to form the reflective structure 30 to obtain a better moisture barrier capability, a low water vapor permeability polymer material is generally more susceptible to ultraviolet light and The blue light is deteriorated by irradiation, and its thermal stability is poor, so it is not suitable for high-power LED light-emitting devices; to solve this problem, the light-emitting device 3 further includes a moisture blocking structure. 60, which surrounds the reflective structure 30 and can cover the outer side of the reflective structure 30, whereby the reflective structure 30 can be selected from a polymer material that is more heat-resistant and more resistant to blue light radiation but does not require low water vapor permeability, and provides The function of reflecting the blue light of the LED chip 10, and the moisture blocking structure 60 can use a polymer material with low water vapor permeability to provide a function of hindering the passage of moisture, so that the light-emitting device 3 can have better heat resistance at the same time. The moisture barrier layer 50 can also be extended to be disposed on the moisture barrier structure 60.

Since the moisture barrier structure 60 can block the passage of moisture, the fourth polymer material 61 included has a low water vapor permeability (for example, not more than 10 g/m ² /day); the fourth polymer material 61 may include, but is not limited to, a resin material or a silicone material, and the resin or silicone material may be selected to have a higher proportion of function groups, such as phenyl or the like, to reduce its water vapor permeability.

The moisture barrier structure 60 may also include optically scattering particles (not shown) that are mixed into the fourth high-sort material 61 and have a weight percentage of not less than 10% in the moisture barrier structure 60. As such, the moisture barrier structure 60 can also appropriately reflect light, reduce the possibility of light being emitted from the side through the moisture barrier structure 60, and the moisture permeability of the moisture barrier structure 60 can be further reduced.

On the other hand, the reflective structure 30 can reflect most of the light generated by the LED chip 10 and the PL structure 20 (especially blue light or ultraviolet light), thereby reducing the dose of light penetrating into the moisture barrier structure 60, so here Under the structural design, the moisture barrier structure 60 is not easily deteriorated by high-dose blue light irradiation, and further, under the buffer of the reflective structure 30, the heat influence of the moisture barrier structure 60 can be reduced, so that material deterioration due to heat is less likely to occur. . At the same time, in order to avoid or reduce the material of the reflective structure 30, it is exposed to blue light and ultraviolet light or is affected by high temperature. Degraded, the resin or silicone material of the third polymer material 31 of the reflective structure 30 may be selected from those which are less susceptible to degradation by blue light and ultraviolet light, and those having better high temperature stability, for example, a functional group having a lower ratio (for example) For example, a resin such as phenyl or the like, or a silicone material.

In the production, the moisture barrier structure 60 can be formed by methods such as dispensing, printing or molding. For example, referring to the manufacturing method of the reflective structure 30 of the foregoing illuminating device 1, after the reflective structure 30 is completed, the manufacturing material of the moisture blocking structure 60 is surrounded by the reflective structure 30 by means of dispensing, printing or molding. It is surrounded and cured to form a moisture barrier structure 60. Further, the optically transparent moisture barrier layer 50 may be disposed on the PL structure 20 before or after the formation of the moisture barrier structure 60 as required by the process. Thus, the light-emitting device 3 having the moisture barrier structure 60 and the light-transparent moisture barrier layer 50 can be formed.

In summary, the light-emitting device 3 passes through the moisture barrier structure 60 to further prevent moisture from contacting the moisture-sensitive material 222.

Although the light-emitting devices 1 to 3 disclosed in the present invention can effectively improve the waterproofness of the wafer-level package light-emitting device, they are only applicable to a single-sided light-emitting chip-level package light-emitting device with a small light-emitting angle. The layered photoluminescence structure of the moisture barrier according to the present invention can also be applied to a five-sided light-emitting wafer level package light-emitting device using a moisture-sensitive photoluminescence material, which is suitable for applications requiring a large illumination angle.

Please refer to FIGS. 4A and 4B, which are schematic views of various types of light-emitting devices 4 according to a fourth preferred embodiment of the present invention. As shown in FIG. 4A, the light-emitting device 4 includes an LED chip 10, a PL structure 20', and a transparent package structure 70, wherein the PL structure 20' is different from the PL structure 20 in the foregoing embodiment (as shown in FIG. 1A). The PL structure 20 has a plate-like structure in appearance and does not cover the façade 13 of the LED chip 10, and the PL structure 20' exhibits a cap-like structure in appearance.

Specifically, the PL structure 20' includes a top portion 201', a vertical portion 202', and a side portion 203'. The top portion 201' is disposed on the upper surface 11 of the LED wafer 10, and the vertical portion 202' is lowered from the top portion 201' The façade 13 of the LED wafer 10 is extended and shielded, and the bottom surface of the pedestal 202' is flush with the lower surface 12 of the LED wafer 10; the side 203' extends outwardly from the pedestal 202'. Since the PL structure 20' is composed of the first PL layer 21 and the second PL layer 22, each of the top 201', the vertical portion 202', and the side portion 203' is composed of the first PL layer 21 and the second PL. A portion of the layer 22 is constructed.

The transparent package structure 70 is disposed on the PL structure 20', and can cover the top surface 201 of the top portion 201', the outer side surface of the vertical portion 202' and the upper surface of the side portion 203', and then the outer side of the transparent package structure 70 can be flush On the side 203 of the side portion 203'; in other possible aspects (not shown), the transparent package structure 70 may also cover the outer side of the side portion 203'. The transparent package structure 70 can comprise a transparent polymeric material 71 that preferably has a low moisture vapor permeability to block the passage of moisture.

As shown in FIG. 4B, the PL structure 20' may further include a third photoluminescent layer (third PL layer) 23, and the third PL layer 23 is disposed under the second PL layer 22, in other words, the second PL layer 22 It is sandwiched between the third PL layer 23 and the first PL layer 21. The third PL layer 23 includes a third polymer material 231 and a non-moisture sensitive photoluminescence material (non-humidity sensitive material) 232 mixed in the third polymer material 231, and the technical contents of the two can be referred to The technical contents of the first polymer material 211 and the non-humidity material 212 of the first PL layer 21.

In the production, the third PL layer 23 is sequentially formed on the LED wafer 10 by the method disclosed in the above-mentioned U.S. Patent Application Publication No. US 2010/0119839 (corresponding to Taiwan Patent No. I508331). The second PL layer 22 and the first PL layer 21 are then formed into a transparent package structure 70 by means of dispensing, printing or molding, and the light-emitting device 4 can be completed.

Thereby, the light generated by the LED chip 10 and the PL structure 20' in the light-emitting device 4 In addition to being able to be emitted upwards, it can also be emitted laterally toward the surroundings, so that the light-emitting device 4 has a wide range of light illumination. In addition, the first PL layer 21, the third PL layer 23, and the transparent encapsulation structure 70 can block the passage of moisture, and reduce the moisture contacting the moisture sensitive material 222 of the second PL layer 22.

The layered photoluminescence structure of the moisture barrier according to the present invention can also be applied to a stent type LED light-emitting device using a moisture-sensitive photoluminescence material. Please refer to FIG. 5A and FIG. 5B, which are schematic views of various types of the light-emitting device 5 according to the fifth preferred embodiment of the present invention. As shown in FIG. 5A, the illuminating device 5 includes a blue LED chip (LED chip) 10', a package structure 80, and a PL structure 20. The LED chip 10' may be horizontal except for the flip chip. Wafer.

The package structure 80 can include a lead frame 81 and a reflector 82. The lead frame 81 can include a first electrode 811 and a second electrode 812, and can be formed by stamping a metal piece, and the two are electrically isolated from each other. . The reflector 82 partially includes the lead frame 81 such that the first and second electrodes 811 and 812 have exposed surfaces for electrically connecting the electrode groups 14 of the LED wafer 10'. The exposed surfaces of the first and second electrodes 811 and 812 are also electrically connectable between wires and electrodes (not shown) of other devices.

The reflector 82 also extends upwardly from the leadframe 81 to form a wall structure (or reflector cup) such that the reflector 82 includes a recess 821. The material composition of the reflector 82 can be referred to the reflective structure 30 (as shown in FIG. 1A), that is, the polymer material and the light-scattering particles are included, so that the reflector 82 can also have a low water vapor permeability; the reflector 82 can also be included. It is made of a material of a reflective resin, for example, polyphthalamide (PPA) or polycyclolexylene-di-methylene Terephthalate (Polycyclolexylene-di-methylene Terephthalate). PCT), Epoxy molding compound (EMC) or silicone tree Silicone molding compound (SMC).

The LED chip 10' is disposed in the recess 821 and electrically connected to the first and second electrodes 811 and 812. The PL structure 20 is disposed on the LED wafer 10' such that the bottom surface 202 of the PL structure 20 directly contacts the LED wafer 10. The upper surface 11 (the same manner as the LED wafer 10 and the PL structure 20 shown in FIG. 1A) is also disposed in the recess 821. Therefore, the light generated by the PL structure 20 and the LED chip 10' is reflected by the reflector 82 and can be emitted only upward. In other possible aspects (ie, as shown in FIG. 5A), the package structure 80 may further include a transparent polymer material 83 disposed between the PL structure 20 and the LED chip 10' such that the two are separated; The upper surface 11 of the LED wafer 10' will likely be connected by wire bonding.

In the fabrication, for example, the LED wafer 10' can be die bonded to the package structure 80, and the U.S. Patent Application No. US2010/0119839 (which corresponds to Taiwan Patent No. I508331). The disclosed method first forms the PL structure 20 and then attaches it to the LED wafer 10' such that the bottom surface 202 of the PL structure 20 directly contacts the upper surface 11 of the LED wafer 10'; or on the surface of the LED wafer 10' A transparent polymer material 83 is formed on the surface 11, and the PL structure 20 is bonded to the transparent polymer material 83 to form different light-emitting devices 5.

The light-emitting device 5 disclosed above is different from the prior art stent-type light-emitting device (for example, US Patent Application No. US 2015/0270451) in that the prior art adds a silicone overlayer to the support. The front side of the illuminating device is configured to reduce the penetration of moisture from the outside to the inner layer of the phosphor material; and the illuminating device 5 disclosed in the present invention replaces the covering layer with the first PL layer 21 including the non-moisture sensitive material 212 to enhance The moisture barrier capability achieves the purpose of protecting the moisture sensitive material 222 in the second PL layer 22, so that a thicker silicone coating layer is not needed, which avoids increasing the overall size of the light emitting device, and solves the disadvantages of the prior art. Used for shortcomings of thin and light electronic products.

As shown in FIG. 5B, the light-emitting device 5 can include a light-transparent moisture barrier layer 50 that can be disposed on the PL structure 20 and can be extended on the reflector 82. In addition, the PL structure 20 and/or the transparent polymer material 83 may also include a moisture absorbing material 242.

In summary, the light-emitting device proposed by the preferred embodiment of the present invention has various moisture blocking mechanisms (for example, PL structure, reflective structure, light transparent moisture barrier layer, moisture barrier structure, moisture absorbing layer, moisture absorbing structure, package) Structures, etc., to reduce or avoid the possibility of moisture permeating from the external environment to the moisture sensitive material; in addition, these moisture barrier mechanisms do not significantly increase the size and manufacturing cost of the light emitting device.

The technical content of the above-described embodiments is not intended to limit the scope of protection of the present invention. It is to be understood that the scope of the invention is to be construed as being limited by the scope of the invention.

1‧‧‧Lighting device

10‧‧‧Blue LED chip, LED chip

11‧‧‧ upper surface

12‧‧‧ Lower surface

13‧‧‧Facade

14‧‧‧Electrode group

20‧‧‧Photoluminescent structure, PL structure

201‧‧‧ top surface

202‧‧‧ bottom

203‧‧‧ side

21‧‧‧First photoluminescent layer, first PL layer

211‧‧‧First polymer material

212‧‧‧ Non-moisture sensitive photoluminescent materials, non-moisture sensitive materials

22‧‧‧Second photoluminescent layer, second PL layer

221‧‧‧Second polymer material

222‧‧‧ Moisture sensitive photoluminescent materials, moisture sensitive materials

30‧‧‧Reflective structure

31‧‧‧ Third polymer material

32‧‧‧Optical scattering particles

Claims (28)

A light-emitting device comprising: a blue LED chip; a photoluminescent structure disposed on the blue LED chip and comprising a first photoluminescent layer and a second photoluminescent layer, the first photoluminescent layer And disposed on the second photoluminescent layer, the first photoluminescent layer comprises a first polymer material and a non-moisture sensitive photoluminescent material mixed in the first polymer material, and the The second photoluminescent layer comprises a second polymer material and a moisture sensitive photoluminescent material mixed in the second polymer material; and a reflective structure surrounding the blue LED chip and the photoluminescent structure, The reflective structure includes a third polymer material and one of the third high-division material. The illuminating device of claim 1, wherein the non-moisture-sensitive photoluminescent material is not less than 50% by weight in the first photoluminescent layer. The light-emitting device of claim 1, wherein the non-moisture-sensitive photoluminescent material has a median diameter (D50) of not more than 30 μm. The light-emitting device of claim 1, wherein the optically scattering fine particles are not less than 30% by weight in the reflective structure. The light-emitting device according to claim 1, wherein the first polymer material and the third polymer material have a water vapor permeability (WVTR) of not more than 10 g/m ² /day. The illuminating device of claim 1, wherein the non-moisture-sensitive photoluminescent material is further an inorganic fluorescent material, and the moisture-sensitive photoluminescent material is more susceptible to oxidation. A fluorescent material of an activator or a quantum dot photoluminescent material. The illuminating device of claim 1, wherein the non-moisture-sensitive photoluminescent material comprises an oxynitride green fluorescent material, the oxynitride green fluorescent material is more β-SiAlON; and the moisture is sensitive The photoluminescent material comprises a fluoride red fluorescent material. The light-emitting device according to any one of claims 1 to 7, further comprising a light-transparent moisture barrier layer, wherein the light-transparent moisture barrier layer is disposed on the photoluminescent structure. The light emitting device of claim 8, wherein the light transparent moisture barrier layer comprises a transparent inorganic layer or a low water vapor permeability polymer layer. The light-emitting device of claim 8, wherein the light-transparent moisture barrier layer is further disposed on the reflective structure. The illuminating device of any one of claims 1 to 7, wherein the photoluminescent structure further comprises a transparent getter layer, the moisture absorbing layer being sandwiched between the first photoluminescent layer and Between the second photoluminescent layers. The illuminating device of any one of claims 1 to 7, wherein the first photoluminescent layer and/or the second photoluminescent layer further comprises a getter material, the moisture absorbing material is mixed In the first polymer material and/or the second polymer material. The light-emitting device according to any one of claims 1 to 7, wherein the reflective structure further comprises a moisture absorbing material mixed in the third polymer material. The light-emitting device according to any one of claims 1 to 7, further comprising a moisture barrier structure surrounding the reflective structure, the moisture barrier structure comprising a fourth polymer material, the fourth high The water vapor permeability of the sub-material is not more than 10 g/m ² /day. The light-emitting device of claim 14, the moisture barrier structure further comprising an optical scattering property And the optical scattering particles are mixed in the fourth high-division material, and the optical scattering particles are not less than 10% by weight in the moisture barrier structure. The illuminating device of any one of claims 1 to 7, further comprising a substrate, and the blue LED chip and the reflective structure are disposed on the substrate. A light emitting device comprising: a blue LED chip; a photoluminescent structure disposed on the blue LED chip and comprising a top portion, a vertical portion extending downward from the top portion, and an outward extending portion from the vertical portion The photoluminescent structure further includes a first photoluminescent layer and a second photoluminescent layer, the first photoluminescent layer is disposed on the second photoluminescent layer; and a transparent package structure Provided on the photoluminescent structure; wherein the first photoluminescent layer comprises a first polymer material and a non-moisture sensitive photoluminescent material mixed in the first polymer material, and the The second photoluminescent layer comprises a second polymer material and a moisture sensitive photoluminescent material mixed in the second polymer material, and the transparent encapsulating structure comprises a transparent polymer material. The illuminating device of claim 17, wherein the photoluminescent structure further comprises a third photoluminescent layer, the second photoluminescent layer being interposed between the third photoluminescent layer and the first photo-induced layer The third photoluminescent layer comprises a third polymer material and a non-moisture sensitive photoluminescent material mixed in the third polymer material. The illuminating device of claim 17, wherein the non-moisture sensitive photoluminescent material has a weight percentage of not less than 50% in the first photoluminescent layer or the third photoluminescent layer. The illuminating device of claim 17, wherein the non-moisture sensitive photoluminescent material has a median particle size of no greater than 30 microns. The light-emitting device according to claim 17, wherein the transparent polymer material contained in the transparent package has a water vapor permeability of not more than 10 g/m ² /day. The illuminating device of any one of claims 17 to 21, further comprising a substrate, and the blue LED chip and the photoluminescent structure are disposed on the substrate. A light-emitting device comprising: a blue LED chip; a package structure comprising a lead frame and a reflector, the lead frame comprising a first electrode and a second electrode, the reflective system partially covering the lead frame and including a recess, the blue LED chip is disposed in the recess and electrically connected to the first electrode and the second electrode of the lead frame; and a photoluminescent structure disposed on the blue LED chip and the a first photoluminescent layer and a second photoluminescent layer disposed in the recess, the first photoluminescent layer being disposed on the second photoluminescent layer, the first photoluminescent layer comprising a first a polymer material and a non-moisture sensitive photoluminescent material mixed in the first polymer material, and the second photoluminescent layer comprises a second polymer material and mixed with the second polymer material One of the moisture sensitive photoluminescent materials. The illuminating device of claim 23, wherein the non-moisture sensitive photoluminescent material has a weight percentage of not less than 50% in the first photoluminescent layer. The illuminating device of claim 23, wherein the non-moisture sensitive photoluminescent material has a median particle size of no greater than 30 microns. The light emitting device of claim 23, wherein the package structure further comprises a transparent polymer material disposed between the photoluminescent structure and the blue LED chip. The illuminating device of claim 23, further comprising a light transparent moisture barrier layer disposed on the photoluminescent structure. The illuminating device of claim 23 or 26, wherein the photoluminescent structure and/or the transparent polymer material further comprises a moisture absorbing material.