Light-emitting diode packaging body and light-emitting device

Abstract

The invention provides a light-emitting diode packaging body and a light-emitting device, in the light-emitting device, the light-emitting surface of an LED chip forms a roughened surface, a first packaging layer and a second packaging layer are sequentially formed above the LED chip, and the refractive index of the first packaging layer is smaller than that of the second packaging layer. The packaging layers with different refractive indexes enable light emitted by the LED chip to be emitted from the packaging layers as much as possible, and the light emitting efficiency of the light emitting device is improved. Besides, by adjusting the thickness of the first packaging layer and the refractive index difference between the second packaging layer and the first packaging layer, the light emitted by the LED chip can be emitted from the packaging layers as much as possible, the light extraction rate of the light-emitting device is improved, and the brightness of the light-emitting device is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and in particular to a light emitting diode package and a light emitting device. Background Art

[0002] The biggest problem facing the LED packaging field has always been the release of the optoelectronic performance of LED chips. In the field of MicroLED direct display applications, as the number of LEDs continues to increase, the requirements for substrate flatness and process accuracy are increasing. COG (Chip on glass) technology is based on glass substrate technology, and it highlights its advantages in flatness, line width and line spacing, heat resistance, etc. At the same time, thanks to the development of mass transfer technology, the yield problem has been improved. However, the packaging structure is still plagued by the problem of light output efficiency.

[0003] In order to improve the light output efficiency, the LED chip is usually processed by forming a DBR structure, surface roughening and other process methods. On the packaging side, due to the refractive index difference between the protective layer and the air, a large amount of light is "trapped" in the protective layer, which is the biggest cause of light performance loss. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the light extraction efficiency of the Micro LED chip packaging end in the prior art, the present application provides a light-emitting diode package and a light-emitting device. In the light-emitting diode package of the present invention, the light-emitting surface of the LED chip is formed as a roughened surface, and a first packaging layer and a second packaging layer are sequentially formed above the LED chip, and the refractive index of the first packaging layer is smaller than the refractive index of the second packaging layer. The packaging layers with different refractive indices enable the light emitted by the LED chip to be emitted from the packaging layer as much as possible, thereby improving the light extraction efficiency of the light-emitting diode package.

[0005] To achieve the above-mentioned and other related purposes, the present invention provides a light emitting diode package, which at least comprises:

[0006] substrate;

[0007] An LED chip is located above the substrate, a light emitting surface of the LED chip is located on a side away from the substrate, and the light emitting surface has a patterned structure;

[0008] A first packaging layer, located above the substrate and covering the LED chip;

[0009] The second encapsulation layer is located above the first encapsulation layer and covers the first encapsulation layer, and the refractive index of the second encapsulation layer is greater than the refractive index of the first encapsulation layer.

[0010] Another aspect of the present invention provides a light emitting diode package, which at least comprises:

[0011] A first transparent layer having a first surface and a second surface oppositely disposed;

[0012] A plurality of LED chips, wherein the LED chips are arranged on the first surface of the first transparent layer from the light emitting surface side;

[0013] The second transparent layer is formed on the light emitting surface side of the LED chip, and the refractive index of the second transparent layer is smaller than the refractive index of the first transparent layer.

[0014] Another aspect of the present invention provides a light-emitting device, which includes a driving substrate and a plurality of light-emitting bodies, wherein the driving substrate is formed with a driving device layer and a driving circuit layer, the light-emitting body includes the light-emitting diode package provided by the present invention, and the driving circuit layer is connected to the circuit layer of the light-emitting diode package.

[0015] As described above, the light emitting diode package and the light emitting device provided by the present invention have at least the following beneficial technical effects:

[0016] In the light-emitting diode package of the present invention, the light-emitting surface of the LED chip is formed as a roughened surface, and a first encapsulation layer and a second encapsulation layer are sequentially formed above the LED chip, and the refractive index of the first encapsulation layer is less than the refractive index of the second encapsulation layer. The encapsulation layers with different refractive indices allow the light emitted by the LED chip to be emitted from the encapsulation layer as much as possible, thereby improving the light extraction efficiency of the light-emitting diode package. In addition, by adjusting the thickness of the first encapsulation layer and the refractive index difference between the first encapsulation layer and the second encapsulation layer, the light emitted by the LED chip can be emitted from the encapsulation layer as much as possible, thereby improving the light extraction rate of the light-emitting diode package and improving its brightness.

[0017] Secondly, a reflective structure is formed on the side of the LED chip in the light-emitting diode package of the present invention that is opposite to the light-emitting surface, so as to increase the light emission efficiency from the light-emitting surface of the LED chip and improve the light extraction rate from the chip end, thereby further improving the light extraction rate of the light-emitting diode package. At the same time, a porous transparent layer can be formed between the light-emitting surface side of the LED chip and the first encapsulation layer, and the refractive index of the porous transparent layer is lower than the refractive index of the first encapsulation layer, thereby forming a structure with a gradual change in refractive index from the porous transparent layer, the first encapsulation layer, and the second encapsulation layer, thereby increasing the light extraction rate of the light-emitting diode package and improving the brightness of the light-emitting diode package. At the same time, the porous transparent layer can also prevent the LED chip from directly contacting the encapsulation glue layer that forms the first encapsulation layer, thereby protecting the LED chip and improving the reliability of the light-emitting diode package. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a light emitting diode package in the prior art.

[0019] Figure 2a Shown is a schematic structural diagram of a light emitting device provided in Embodiment 1 of the present invention.

[0020] Figure 2b The diagram shows a schematic structural diagram of a light emitting device of an optional embodiment of the first embodiment.

[0021] Figure 3 Display as Figure 2a The schematic diagram of the structure of the LED chip in the second light emitting device is shown.

[0022] Figure 4 The graph shows the influence of the refractive index of the second encapsulation layer on the brightness of the light-emitting device when the second encapsulation layer is provided alone.

[0023] Figure 5 The graph shows the influence of the refractive index of the first encapsulation layer on the brightness of the light-emitting device when the first encapsulation layer is provided alone.

[0024] Figure 6 It shows a curve diagram showing the influence of the refractive index of the second encapsulation layer on the brightness of the light-emitting device when the first encapsulation layer and the second encapsulation layer are provided at the same time.

[0025] Figure 7 The graph shows the effect of the thickness of the first encapsulation layer on the brightness of the light-emitting device when the first encapsulation layer and the second encapsulation layer are provided at the same time.

[0026] Figure 8a Shown is a schematic structural diagram of a light emitting device provided in Embodiment 2 of the present invention.

[0027] Figure 8b The diagram shows a schematic structural diagram of a light emitting device of an optional embodiment of the second embodiment.

[0028] Fig. 9 Shown is a schematic structural diagram of a light emitting diode package provided in Embodiment 3 of the present invention.

[0029] Fig.10 Displayed as having Fig. 9 A simulation diagram of the light emission effect of structures with different layers is shown.

[0030] Fig.11 Shown is a schematic structural diagram of a light-emitting device provided in Embodiment 4 of the present invention.

[0031] Fig.12 Display as Fig.11 Schematic diagram of the cross-sectional structure along the CC line.

[0032] Reference numerals

[0033] 11. Glass substrate; 12. LED chip; 13. Lead-out circuit; 14. Packaging glue.

[0034] 100, light emitting diode package; 110, substrate; 120, LED chip; 121, epitaxial structure; 1211, first semiconductor layer; 1212, active layer; 1213, second semiconductor layer; 122, current spreading layer; 123, electrode structure; 124, reflective structure; 1231, first electrode; 1232, second electrode; 130, circuit layer; 131, lead-out electrode; 140, first packaging layer; 150, second packaging layer; 160, porous transparent layer.

[0035] 200, light-emitting diode package; 210, first transparent layer; 2101, first surface; 2102, second surface; 220, second transparent layer; 230, filling layer; 240, bonding layer; 250, insulating layer; 260, circuit layer; 261, wiring layer; 262, pad layer.

[0036] 300, light-emitting device; 301, driving substrate; 302, light-emitting body; 303, driving circuit layer; 304, driving device layer; 305, housing. DETAILED DESCRIPTION

[0037] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0038] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Although the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation, the form, quantity, positional relationship and proportion of each component in actual implementation can be changed at will under the premise of realizing the technical solution of this party, and the component layout form may also be more complicated.

[0039] like Figure 1As shown, the existing micro LED packaging structure includes a glass substrate 11, an LED chip 12 located above the glass substrate, and a packaging layer 14 located above the glass substrate 11 and wrapping the LED chip 12. The LED chip 12 is led out to the driving end through the lead-out line 13 in the glass substrate 11. The above-mentioned packaging layer 14 is mostly a transparent adhesive layer. There is a large refractive index difference between the refractive index of the transparent adhesive layer and the refractive index of the external air, which causes most of the light emitted by the LED chip 12 to be trapped in the packaging layer and unable to be emitted, resulting in defects such as poor light emission effect and low brightness of the device. In order to solve this problem, the present invention provides a light-emitting diode package and a light-emitting device. It is now described in detail through the following specific embodiments.

[0040] Embodiment 1

[0041] This embodiment provides a light emitting device, such as Figure 2a As shown, the light emitting device 100 of this embodiment at least includes a substrate 110 , a plurality of LED chips 120 located above the substrate 110 , and a first packaging layer 140 and a second packaging layer 150 located above the substrate 110 and encapsulating the LED chips 120 .

[0042] Optionally, the substrate 110 may be a driving substrate such as a glass substrate, a PCB substrate, etc. In this embodiment, the substrate 110 is a glass substrate.

[0043] In this embodiment, the LED chip 120 is a micro LED chip, and its thickness is about 5 μm to 15 μm. Figure 3As shown, the LED chip 120 includes an epitaxial structure 121, which includes a first semiconductor layer 1211, an active layer 1212 and a second semiconductor layer 1213 arranged in sequence from bottom to top. The epitaxial structure 121 can be a structure that can radiate light of any color, for example, it can be an AlGaInP red light epitaxial structure, a GaN green light epitaxial structure, a GaN blue light epitaxial structure, a GaN ultraviolet light epitaxial structure, etc. The first semiconductor layer 1211 can be an N-type semiconductor layer, and the second semiconductor layer 1213 can be a P-type semiconductor layer, or vice versa. The active layer 1212 can be a single quantum well structure or a multiple quantum well structure composed of a quantum well layer and a quantum barrier layer. The side of the first semiconductor layer 1211 away from the active layer 1212 forms the light-emitting side of the LED chip 120. In order to increase the light-emitting effect at the end of the LED chip 120, in this embodiment, a patterned structure is formed on the light-emitting surface of the LED chip 120. The patterned structure may be a patterned structure (PSS pattern) formed when the first semiconductor layer 1211 is formed on the patterned substrate when the epitaxial structure 121 is formed, or may be a roughened surface obtained by performing a separate roughening treatment on the light-emitting surface side after the epitaxial structure 121 is formed. The formation of the patterned structure can increase the reflection and refraction of the light radiated by the active layer 1212, thereby increasing the light emission rate from the light-emitting surface, and improving the light extraction efficiency at the end of the LED chip 120 and the brightness of the LED chip 120.

[0044] like Figure 3 As shown, a current spreading layer 122 is formed on one side of the second semiconductor layer 1213 of the epitaxial structure 121 away from the active layer 1212, and the current spreading layer 122 covers at least a portion of the surface of the second semiconductor layer 1213, and further, can also completely cover the surface of the second semiconductor layer 1213. The current spreading layer 122 can increase the lateral diffusivity of the current and improve the uniformity of light output.

[0045] Likewise Figure 3 As shown, a reflective structure 124 is formed on one side of the epitaxial structure 121 opposite to the light emitting surface. The reflective structure 124 covers the current spreading layer 122 above the second semiconductor layer 1213 and the surface of the epitaxial structure 121 not covered by the current spreading layer 122. Furthermore, the reflective structure 124 also covers the sidewalls of the epitaxial structure 121. Figure 3 As shown, the epitaxial structure 121 is formed with an electrode table, which exposes the first semiconductor layer 1211 and is used to form a first electrode 1231 connected to the first semiconductor layer 1211. The above-mentioned reflective structure 124 covers the surface and sidewalls of the electrode table at the same time. In an optional embodiment, the above-mentioned reflective structure 124 can be a DBR structure formed by alternately stacking material layers with different refractive indices, such as SiO2 layers, SiN x Layer, SiOx N y The DBR structure can be formed by alternating any two layers of Ti2O3 layer and TiO2 layer. It can also be a total reflection structure formed by a DBR structure and a metal layer. For example, the total reflection structure formed by the above DBR structure and metal Ag, Al, Au, etc., so as to reflect as much light radiated thereto as possible to the light-emitting surface side for emission.

[0046] Also refer to Figure 3 , the LED chip 120 also includes an electrode structure 123, which includes a first electrode 1231 and a second electrode 1232 located above the reflective structure 124 and spaced apart. The first electrode 1231 is formed on the electrode table and connected to the first semiconductor layer 1211, and the second electrode 1232 is formed on the epitaxial structure 121 and connected to the second semiconductor layer 1213. Optionally, the electrode structure 123 includes a metal adhesion layer material such as evaporated Cr, Ti, and a barrier layer material such as Ni, Pt, and Au, Sn, Sn63-Pb37 alloy, Sn-Ag3-Cu 0.5 (SAC305) alloy, Sn-Ag3-Cu 0.7 (SAC307) alloy or other metal materials. The thickness of the electrode structure 123 is between 1 μm and 2.5 μm, for example, 1 μm, 1.5 μm, 2 μm, etc.

[0047] like Figure 2a As shown, a circuit layer 130 is provided in the substrate 110 of the light-emitting device 100 of this embodiment, and the circuit layer 130 includes a plurality of groups of lead-out electrodes 131, and each group of lead-out electrodes 131 is connected to an electrode structure 123 of an LED chip, thereby realizing electrical connection between the LED chip 120 and the circuit layer 130, and then being led out to the driving end by the above-mentioned circuit layer 130.

[0048] Refer again Figure 2a In the light emitting device 100 , a first encapsulation layer 140 and a second encapsulation layer 150 are disposed above the LED chip 120 . The first encapsulation layer 140 is located above the LED chip 120 , that is, the first encapsulation layer 140 covers the light emitting surface of the LED chip 120 .

[0049] In an optional embodiment, if Figure 2bAs shown, the first encapsulation layer 140 is not only formed above the light emitting surface of the LED chip 120, but also formed above the substrate 110 between the LED chips 120 and completely covers the LED chips 120. In an optional embodiment, in order to better cover the LED chip 120, the thickness of the first encapsulation layer 140 is greater than the thickness of the LED chip 120. In an optional embodiment, the thickness of the above-mentioned LED chip 120 is approximately 5μm to 15μm. The thickness of the first encapsulation layer 140 is between 5μm and 100μm, further between 10μm and 50μm, and further between 20μm and 40μm, for example, 15μm, 30μm, 35μm, etc. The refractive index of the first encapsulation layer 140 is between 1.0 and 1.5, and further between 0.8 and 1.3. The first encapsulation layer 140 is a transparent adhesive layer, for example, it can be a porous material (for example, aerogel, porous silicon oxide layer, etc.), a fluorine-containing material, methyl silicone, etc. The thickness of the first encapsulation layer 140 can be determined comprehensively according to the overall size of the light emitting device 100 and the material selection of the first encapsulation layer 140. For example, when the first encapsulation layer 140 is aerogel, its thickness ranges from 5 μm to 20 μm; when the first encapsulation layer 140 is a fluorine-containing material or a methyl material, its thickness ranges from 10 μm to 100 μm.

[0050] Also refer to Figure 2a and Figure 2b , the second encapsulation layer 150 is located above the first encapsulation layer 140 and completely covers the first encapsulation layer 140. The thickness of the second encapsulation layer 150 is greater than the thickness of the first encapsulation layer 140, and its refractive index is greater than the thickness of the first encapsulation layer 140. In an optional embodiment, the thickness of the second encapsulation layer 150 is between 20μm and 500μm, further, between 50μm and 300μm, and further, between 100μm and 200μm, such as 40μm, 45μm, 50μm, 60μm, 70μm, 100μm, 200μm, 300μm, etc. The thickness of the second encapsulation layer 150 can be selected according to the product thickness requirements of the light-emitting diode. The refractive index of the second encapsulation layer 150 is between 1.4 and 2.0, and is greater than the refractive index of the first encapsulation layer 140. The difference in refractive index between the second encapsulation layer 150 and the first encapsulation layer 140 is between 0.1 and 0.5, and further is about 0.2. The second encapsulation layer is also a transparent adhesive layer, for example, it can be various resins such as phenyl silicone, epoxy resin, acrylic resin, etc. or glass.

[0051] In an optional embodiment, in order to obtain light of a desired color, a light conversion agent may be provided in the first encapsulation layer 140 and / or the second encapsulation layer 150. For example, phosphors or quantum dots dispersed in the first encapsulation layer 140 and / or the second encapsulation layer 150 may be provided.

[0052] In order to further obtain the optimal thickness and refractive index selection of the above-mentioned first encapsulation layer 140 (A) and the second encapsulation layer 150 (B), this embodiment simulates the influence of the thickness and refractive index of each of the first encapsulation layer 140 and the second encapsulation layer 150 on the brightness of the light-emitting device 100, and the influence of the two together on the brightness of the light-emitting device 100. Specifically, an optical simulation analysis is performed on the structure of the MicroLED-COG direct display technology. To simplify the simulation, the glass substrate is omitted, and the package size of a single unit is set to 0.2mm*0.2mm, the chip thickness is 6um, and taking a GaN-based chip with a refractive index of 2.3 as an example, the energy of the light source emitted from the chip surface is 100W, the thickness of the second encapsulation layer 150 is 50μm, and the transmittance between each layer is 1; the energy of the lost light in the positive direction of the Z axis (the thickness direction of the LED chip 120) is taken as a consideration indicator for the above simulation.

[0053] like Figure 4 As shown, it shows that when the light emitting device 100 does not have the first encapsulation layer 140, but only has the second encapsulation layer 150, and the thickness of the second encapsulation layer 150 is 50 μm, the refractive index of the second encapsulation layer 150 affects the brightness of the light emitting diode encapsulation layer. The relevant data of the simulation are shown in Table 1 below. Figure 4 As shown in Table 1, as the refractive index of the second encapsulation layer 150 increases, the brightness of the light emitting device 100 decreases, especially after the refractive index reaches 1.5, the brightness of the light emitting device 100 decreases significantly, and is basically below 50% of the chip energy. Therefore, in this embodiment, the refractive index of the second encapsulation layer 150 is preferably not less than 1.5.

[0054] Table 1 Refractive index N(B) of the second encapsulation layer and brightness (E / W) of the light-emitting device and brightness data of the light-emitting diode encapsulation layer

[0055] N(B) E / W 1.0 100 1.1 95.966 1.2 83.941 1.3 74.766 1.4 66.967 1.5 58.379 1.6 50.638 1.7 45.259 1.8 53.353 1.9 44.886 2.0 41.418

[0056] like Figure 5 As shown, it shows the influence of the refractive index of the first encapsulation layer 140 on the brightness of the light-emitting device 100 and the brightness ratio of the light-emitting device 100 when the light-emitting device 100 is provided with a first encapsulation layer 140 and a second encapsulation layer 150, the thickness of the first encapsulation layer 140 is 1 μm, the thickness of the second encapsulation layer 150 is 50 μm, and the refractive index is 1.5. The relevant data of the simulation are shown in Table 2 below, in which NoA represents the brightness and brightness ratio of the light-emitting device 100 when the first encapsulation layer 140 is not present, and the Ratio column represents the brightness ratio of the light-emitting device 100 with different refractive indices and the light-emitting device 100 without the first encapsulation layer 140. By Figure 5As shown in Table 2, as the refractive index of the first encapsulation layer 140 increases, the brightness of the light-emitting device 100 also decreases, especially after the refractive index is greater than 1.6, the brightness of the light-emitting device 100 decreases significantly, basically below 50% of the chip energy. However, the brightness of the light-emitting diode does not increase with the increase of the refractive index of the first encapsulation layer 140, but decreases with the increase of the refractive index of the first encapsulation layer 140. After the refractive index is greater than 1.3, the brightness gradually becomes less than 100%. Therefore, in this embodiment, the refractive index of the first encapsulation layer 140 is preferably less than 1.3.

[0057] Table 2 Data of the refractive index N(A) of the first encapsulation layer and the brightness (E / W) and brightness ratio (Ratio) of the light-emitting device

[0058] N(A) E / W Ratio NoA 58.379 100.00％ 1.0 85.187 145.92％ 1.1 74.675 127.91％ 1.2 66.123 113.27％ 1.3 60.081 102.92％ 1.4 58.175 99.65％ 1.5 58.814 100.75％ 1.6 53.625 91.86％ 1.7 48.875 83.72％ 1.8 42.428 72.68％ 1.9 37.277 63.85％ 2.0 33.629 57.60％

[0059] like Figure 6 As shown, it shows that when the light-emitting device 100 is provided with a first encapsulation layer 140 and a second encapsulation layer 150, the first encapsulation layer 140 has a thickness of 1 μm, a refractive index of 1.3, and the second encapsulation layer 150 has a thickness of 50 μm, the effect of the refractive index of the second encapsulation layer 150 on the brightness of the light-emitting device 100 and the brightness ratio of the light-emitting device 100. The relevant data of the simulation are shown in Table 3 below. In Table 3, E / W (NoA) represents the brightness of the light-emitting device 100 when the first encapsulation layer 140 is not present, and the Ratio column represents the brightness ratio of the light-emitting device 100 having the first encapsulation layer 140 and the second encapsulation layer 150 with different refractive indices to the light-emitting device 100 having no first encapsulation layer 140 but having a second encapsulation layer 150 with different refractive indices. Figure 6 As shown in Table 3, when the refractive index of the second encapsulation layer 150 is less than 1.5, the brightness of the light-emitting device 100 is slightly improved, but the brightness ratio is not significantly increased compared with the light-emitting device 100 without the first encapsulation layer 140. When the refractive index of the second encapsulation layer 150 is greater than 1.5, the brightness of the light-emitting device 100 is slightly reduced, but the reduction is less than 10, but the brightness ratio is significantly increased compared with the light-emitting device 100 without the first encapsulation layer 140. Considering the above two aspects, the refractive index of the second encapsulation layer 150 in this embodiment is selected to be about 1.5.

[0060] Table 3 Data of refractive index N(B) of the second encapsulation layer and brightness (E / W) and brightness ratio (Ratio) of the light emitting device

[0061] N(B) E / W E / W(NOA) Ratio 1.0 66.24 100 66.24％ 1.1 74.617 95.966 77.75％ 1.2 77.347 83.941 92.14％ 1.3 75.288 74.766 100.70％ 1.4 65.729 66.967 98.15％ 1.5 60.081 58.379 102.92％ 1.6 57.234 50.638 113.03％ 1.7 55.719 45.259 123.11％ 1.8 54.757 53.353 102.63％ 1.9 53.09 44.886 118.28％ 2.0 52.076 41.418 125.73％

[0062] like Figure 7As shown, it shows the effect of the thickness of the first encapsulation layer 140 on the brightness of the light-emitting device 100 and the brightness ratio of the light-emitting device 100 when the light-emitting device 100 is provided with a first encapsulation layer 140 and a second encapsulation layer 150, the refractive index of the first encapsulation layer 140 is 1.3, the thickness of the second encapsulation layer 150 is 50μm, and the refractive index is 1.5. The relevant data of the simulation are shown in Table 4 below. The Ratio column in Table 4 represents the brightness ratio of the light-emitting device 100 with different first encapsulation layers 140 and the light-emitting device 100 without the first encapsulation layer 140 (that is, the thickness of the first encapsulation layer 140 is 0). Figure 7 As shown in Table 4, as the thickness of the first encapsulation layer 140 increases, the brightness of the light emitting device 100 also increases. However, considering the overall size of the light emitting diode and the protection of the LED chip 120, in this embodiment, the first encapsulation layer 140 is aerogel, and its thickness should not be too thick. In this embodiment, the thickness of the first encapsulation layer 140 is less than 20 μm, and is further controlled to be about 10 μm.

[0063] Table 4 Data on the thickness T of the first encapsulation layer and the brightness (E / W) and brightness ratio (Ratio) of the light-emitting device

[0064] T / um E / W Ratio 0 58.379 100.00％ 1 60.081 102.92％ 3 64.189 109.95％ 5 66.462 113.85％ 7 68.006 116.49％ 9 67.517 115.65％ 11 69.885 119.71％ 13 72.035 123.39％

[0065] A comprehensive analysis of the above four simulation results shows that when the refractive index of the first encapsulation layer 140 is about 1.3 and the thickness is about 7 μm, the refractive index of the second encapsulation layer 150 is about 1.5 and the thickness is about 50 μm, and the refractive index of the first encapsulation layer 140 is about 0.2 lower than the refractive index of the second encapsulation layer 150, the brightness of the light-emitting device 100 can be increased to about 116.49%.

[0066] Embodiment 2

[0067] This embodiment also provides a light emitting device, such as Figure 8a As shown, the second light emitting device 100 also includes a substrate 110, an LED chip 120 located above the substrate 110, and a first packaging layer 140 and a second packaging layer 150 located above the substrate 110 and covering the LED chip 120. The same points as those in the first embodiment are not repeated here, and the difference is that:

[0068] like Figure 8aAs shown, in this embodiment, a porous transparent layer 160 is further formed above the LED chip 120 and between the first packaging layer 140. The porous transparent layer 160 is a material layer with a lower refractive index than the first packaging layer 140, for example, it can be an aerogel or a porous SiO2 layer, and its refractive index is less than 1.4, and further, less than 1.3. The porous transparent layer 160 is formed above the LED chip 120 to isolate the light emitting surface of the LED chip 120 from the first packaging layer 140. Optionally, the porous transparent layer 160 can also be formed on the light emitting surface and side wall of the LED chip 120 at the same time, that is, the porous transparent layer 160 wraps the entire LED chip 120, isolating it from the first packaging layer 140 and the second packaging layer 150.

[0069] like Figure 8a As shown, the first encapsulation layer 140 is formed on the porous transparent layer 160, and the second encapsulation layer 150 is formed on the first encapsulation layer 140 and on the exposed substrate 110. In an optional embodiment, as Figure 8b As shown, the first encapsulation layer 140 is not only formed on the porous transparent layer 160, but also formed on the exposed substrate 110, and the second encapsulation layer 150 is formed on the first encapsulation layer 140. As described above, since the porous transparent layer 160 covers at least the light-emitting surface of the LED chip 120, the light-emitting surface of the LED chip 120 is at least isolated from the first encapsulation layer 140, ensuring that the light-emitting surface of the LED chip remains in a roughened state, which is beneficial to improving the light-emitting effect. When the porous transparent layer 160 covers the light-emitting surface and sidewall of the LED chip 120 at the same time, it can avoid contact between the LED chip 120 and the first encapsulation layer 140, while ensuring the light-emitting effect of the LED chip, it can also effectively improve the reliability of the product. In an optional embodiment, the thickness of the porous transparent layer 160 is between 0.5μm and 5μm, and further, between 1μm and 3μm, for example, 1μm, 1.5μm, 2μm, 3μm, etc.

[0070] When the refractive index of the first encapsulation layer 140 is about 1.3 and the thickness is about 7μm, and the refractive index of the second encapsulation layer 150 is about 1.5 and the thickness is about 50μm, and the refractive index of the first encapsulation layer 140 is about 0.2 lower than the refractive index of the second encapsulation layer 150, the thickness of the porous transparent layer 160 is set to about 1μm and the refractive index is set to about 1.2. The light emission simulation of the light emitting diode shows that under the above conditions, the forward lost light energy of the light emitting diode in the Z axis is 71.33W, and the brightness is increased to 122.18.

[0071] Embodiment 3

[0072] This embodiment provides a light emitting diode package, such as Fig. 9As shown, the light emitting diode package 200 of this embodiment includes a first transparent layer 210, a plurality of LED chips 120 located on one side of a first surface 2101 of the first transparent layer 210, and a second transparent layer 220 formed on one side of a light emitting surface of the LED chips. Specifically, the first transparent layer 210 can be a packaging glue layer or a transparent material such as sapphire. In this embodiment, the first transparent layer 210 is sapphire.

[0073] The first transparent layer 210 has a first surface 2101 and a second surface 2102, wherein the second surface 2102 is the light emitting side of the light emitting diode package 200, and the LED chip is fixed on the first surface 2101. In order to fix the above-mentioned LED chip on the first surface 2101 side, an adhesive layer 240 is formed on the first surface 2101 of the first transparent layer 210, and the adhesive layer 240 adheres to the light emitting side of the LED chip to fix the LED chip to the first transparent layer 210. The above-mentioned LED chip is the same as the LED chip described in the first embodiment. In this embodiment, the light emitting diode package 200 preferably includes three LED chips, namely a red light chip, a green light chip and a blue light chip, to form a single pixel package.

[0074] In this embodiment, a patterned structure is formed on the light-emitting surface of the LED chip, and the patterned structure can also be a patterned structure (PSS pattern) formed when an epitaxial structure is generated on a patterned substrate, or a roughened surface obtained by performing a separate roughening treatment on the light-emitting surface side after the epitaxial structure is formed. At the same time, a second transparent layer 220 is also formed on the light-emitting surface, and the refractive index of the second transparent layer 220 is less than the refractive index of the first transparent layer 210. The second transparent layer 220 has a similar configuration to the first encapsulation layer 140 in the light-emitting device provided in Example 1. Specifically, the thickness of the second transparent layer 220 is between 0.5 μm and 100 μm, between 20 μm and 40 μm, or between 0.5 μm and 5 μm, and further, between 1 μm and 3 μm. Its refractive index is between 1.0 and 1.5, and further between 0.8 and 1.3. The second transparent layer 220 can be, for example, a porous material (for example, aerogel or porous SiO2, etc.) layer, a fluorine-containing material, methyl silicone, etc. The thickness of the second transparent layer 220 can be determined comprehensively according to the overall size of the light-emitting diode package 200 and the material selection of the second transparent layer 220. For example, when the second transparent layer 220 is aerogel, its thickness ranges from 5μm to 20μm; when the second transparent layer 220 is a fluorine-containing material or a methyl material, its thickness ranges from 10μm to 100μm. Further, in order to ensure the patterned structure of the light-emitting surface of the LED chip, in this embodiment, the second transparent layer 220 is a porous transparent layer, the first transparent layer 210 is sapphire, and its refractive index is about 1.7, and the refractive index of the second transparent layer 220 formed by aerogel or a porous SiO2 layer is less than 1.4, and further less than 1.3. The second transparent layer 220 formed by the above material is formed into a loose and porous material layer, so the roughened structure of the light-emitting surface will not be filled, and the roughened state of the light-emitting surface will be maintained, thereby ensuring the favorable effect of the roughened structure on the light-emitting effect.

[0075] Refer again Fig. 9 The light emitting diode package 200 of this embodiment further includes a filling layer 230, which is filled between the LED chips and wraps the side walls of the LED chips. Furthermore, the filling layer 230 fills the gaps between the LED chips and wraps the side walls of the LED chips, while wrapping the side walls of the second transparent layer 220 and covering the bonding layer 240. The other side of the filling layer 230 exposes the electrode structure of the LED chip to facilitate subsequent electrical connection of the electrode structure.

[0076] An insulating layer 250 is also formed on the side of the filling layer 230 away from the bonding layer 240. The insulating layer 250 covers the filling layer 230 and the exposed LED chip portion, thereby protecting the light-emitting diode package 200. A circuit layer 260 is also formed between the insulating layer 250 and the filling layer 230. The circuit layer 260 includes a wiring layer 261 formed above the filling layer 230 and electrically connected to the electrode structure of the LED chip, and a pad layer 262 connected to the wiring layer 261. The insulating layer 250 covers the wiring layer 261 while exposing the pad layer 262. The wiring layer 261 can realize the series connection of the first electrodes of multiple LED chips, and at the same time, the first electrodes after the series connection are led out from the pad layer 262. The multiple second electrodes of the multiple LED chips are led out through the wiring layer 261 and the pad layer 262 respectively.

[0077] In order to verify the effect of the formation of the second transparent layer 220 on the light emission of the light emitting diode package 200, Fig. 9 The light-emitting effects of different structures of the luminous bodies were simulated. The simulation results are as follows Fig.10 As shown. Fig.10 As shown, compared with the bare LED chip, the formation of the filling layer 230 on the side wall of the LED chip has little effect on the brightness of the LED chip, but after the filling layer 230 is formed, the bonding layer 240 is directly formed, which will cause the brightness to drop significantly, especially when the light output angle is within the range of ±60 degrees. Then, after the first transparent layer 210 (sapphire) is formed on the bonding layer 240, the brightness effect of the light emitting diode package 200 is further reduced, especially when the light output angle is within the range of 20°~60°, -60°~-20°, the brightness reduction is more obvious. After the second transparent layer 220 (porous SiO2) layer is formed between the bonding layer 240 and the LED chip, the brightness of the light emitting diode is slightly reduced compared with the structure in which the filling layer 230 is formed between the bare LED chip and the LED chip, but the brightness of the light emitting diode package 200 is significantly improved compared with the structure in which the second transparent layer 220 is not provided. In particular, the brightness improvement is more obvious when the light output angle is within the range of 20°~60°, -60°~-20°.

[0078] Embodiment 4

[0079] This embodiment provides a light emitting device, such as Fig.11 and Fig.12 As shown, the light emitting device 300 includes a driving substrate 301 and a light emitting body 302 fixed on the driving substrate 301. In this embodiment, the light emitting body 302 may be the light emitting diode package 200 provided in the third embodiment.

[0080] Also refer to Fig.11 and Fig.12The light emitting device 200 further includes a housing 305 to protect the plurality of light emitters. The driving substrate 301 is provided with a driving device layer 304 and a driving circuit layer 303 located above the driving device layer. The driving circuit layer 303 is electrically connected to each driving device in the driving device layer 304 .

[0081] The LED package 200 is connected to the driving circuit layer 303 via the pad layer 262 in the circuit layer 260 , so that the driving device in the driving device layer 304 can control the LED package 200 .

[0082] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A light emitting device, characterized in that: At least: substrate; A plurality of LED chips are located above the substrate, wherein the light emitting surfaces of the LED chips are located at a side away from the substrate, and the light emitting surfaces have a patterned structure; A first packaging layer, located above the LED chip and at least covering the light emitting surface of the LED chip; The second packaging layer is located above the first packaging layer, covers the first packaging layer and the exposed surface of the substrate, and the refractive index of the second packaging layer is greater than the refractive index of the first packaging layer.

2. The light emitting device according to claim 1, characterized in that: The refractive index of the first encapsulation layer is between 1.0 and 1.

5.

3. The light emitting device according to claim 1, characterized in that: The refractive index of the second encapsulation layer is between 1.4 and 2.

0.

4. The light emitting device according to any one of claims 1 to 3, characterized in that: The difference in refractive index between the second encapsulation layer and the first encapsulation layer is between 0.1 and 0.

5.

5. The light emitting device according to claim 1, characterized in that: The thickness of the first encapsulation layer is between 5 μm and 100 μm.

6. The light emitting device according to claim 1, characterized in that: The thickness of the second encapsulation layer is between 20 μm and 500 μm.

7. The light emitting device according to claim 1, characterized in that: It also includes a porous transparent layer, which is located between the LED chip and the first packaging layer, and at least covers the light emitting surface of the LED chip.

8. The light emitting device according to claim 7, characterized in that: The refractive index of the porous transparent layer is smaller than the refractive index of the first encapsulation layer.

9. The light emitting device according to claim 8, characterized in that: The thickness of the porous transparent layer is between 0.5 μm and 20 μm.

10. The light emitting device according to claim 7, characterized in that: The porous transparent layer is an aerogel or a porous silicon oxide layer.

11. The light emitting device according to claim 1, characterized in that: The LED chip comprises: An epitaxial structure, the epitaxial structure comprising a first semiconductor layer, an active layer and a second semiconductor layer arranged in sequence, wherein a side of the first semiconductor layer away from the active layer forms the light emitting surface; The electrode structure is located on a side of the second semiconductor layer away from the active layer. The LED chip is fixed to the substrate via one side of the electrode structure. The electrode structure includes a first electrode connected to the first semiconductor layer and a second electrode connected to the second semiconductor layer.

12. The light emitting device according to claim 11, characterized in that: A circuit layer is arranged in the substrate, and the electrode structure is connected to the circuit layer.

13. The light emitting device according to claim 11, characterized in that: A reflective structure is also formed on a side of the second semiconductor layer away from the active layer, and the electrode structure is located above the reflective structure.

14. The light emitting device according to claim 1, characterized in that: The plurality of LED chips include a plurality of pixel units consisting of red light chips, green light chips and blue light chips.

15. A light emitting diode package, characterized in that: At least: A first transparent layer having a first surface and a second surface oppositely disposed; A plurality of LED chips, wherein the LED chips are arranged on the first surface of the first transparent layer from the light emitting surface side; The second transparent layer is formed on the light emitting surface side of the LED chip, the refractive index of the second transparent layer is smaller than the refractive index of the first transparent layer, and the second transparent layer is a porous transparent layer.

16. The light emitting diode package according to claim 15, characterized in that: The second transparent layer is an aerogel or a porous silicon oxide layer.

17. The light emitting diode package according to claim 15, characterized in that: Also includes: A filling layer, formed between the plurality of LED chips and covering the side walls of the LED chips; an adhesive layer formed on the first surface of the first transparent layer to fix the plurality of LED chips; An insulating layer, located on a side of the filling layer away from the bonding layer; The circuit layer includes a wiring layer formed between the filling layer and the insulating layer, and a pad layer led out from the wiring layer, wherein the insulating layer wraps the side wall of the pad layer.

18. The light emitting diode package according to claim 14, characterized in that: The plurality of LED chips include a red light chip, a green light chip and a blue light chip.

19. The light emitting diode package according to claim 15, characterized in that: The refractive index of the second transparent layer is smaller than the refractive index of the first transparent layer.

20. The light emitting diode package according to claim 15, characterized in that: The thickness of the second transparent layer is between 0.5 μm and 5 μm.

21. A light emitting device, characterized in that: It comprises a driving substrate and a plurality of light-emitting bodies, wherein a driving device layer and a driving circuit layer are formed in the driving substrate, the light-emitting body comprises the light-emitting diode package according to any one of claims 15 to 20, and the driving circuit layer is electrically connected to the light-emitting diode package.

Images