Light emitting diode packaging structure
By employing a deep isolation trench design and an insulating protective layer in COB packaging, the corrosion problem of GaN epitaxial structure caused by KSF powder hydrolysis was solved, improving the stability and luminous efficacy of LED packaging.
Patent Information
- Application Number
- CN202423074972.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2034-12-12
AI Technical Summary
In COB packaging, harmful ions generated after the hydrolysis of KSF phosphor react chemically with the GaN epitaxial structure, leading to corrosion, affecting the electrical and optical performance of the LED chip, and shortening its service life.
A deep isolation trench design is adopted down to the substrate layer, and an insulating protective layer is covered on the side and front of the epitaxial structure of the LED chip to prevent moisture from directly contacting the GaN epitaxial structure. At the same time, insulating protective layer materials such as SiO2, Al2O3, and SiNx are used, and the width of the isolation trench and the thickness of the protective layer are controlled to ensure effective protection.
It effectively prevents the reaction between harmful ions and the GaN epitaxial structure, improves the long-term stability and luminous efficacy of LED packaging, and protects the epitaxial structure from corrosion.
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Figure CN223681444U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to diode technical field especially is a kind of light-emitting diode packaging structure. BACKGROUND
[0002] With the rapid development of semiconductor technology, light-emitting diode (LED) as energy-efficient light source, has been widely used in lighting, display and other fields. In order to further enhance the light efficiency and performance of LED, chip on board (Chip on Board, COB) packaging technology because of its superior heat dissipation performance and high integration, become one of the mainstream LED packaging methods. In COB packaging, the application of fluorescent powder is particularly key, which can effectively convert the blue light or ultraviolet light emitted by LED chip, and improve the overall light efficiency.
[0003] In recent years, KSF (fluoride) powder because of its excellent fluorescent conversion efficiency and stability, is widely incorporated into COB packaging to enhance the light efficiency performance of LED. The application of KSF powder in COB packaging not only can significantly improve the light output efficiency, but also can optimize the light color quality, meet the diversified lighting needs. However, in the long-term aging test process, researchers found that when the fluorescent adhesive layer in COB packaging is invaded by water vapor, the peripheral protective film of KSF powder is damaged. This damage leads to hydrolysis reaction of KSF powder, generating harmful ions such as fluoride ion (F⁻) and hydroxyl ion (OH⁻). After the conventional vertical LED chip is cut, the GaN epitaxial structure on the side is exposed. Under external light conditions, the generated OH⁻ ion reacts with GaN material, causing corrosion of GaN epitaxial structure. This corrosion not only weakens the electrical and optical performance of LED chip, but also eventually leads to performance failure of LED device, shortening its service life. SUMMARY
[0004] Therefore, the utility model provides a kind of light-emitting diode packaging structure, the chip in the COB containing KSF powder is protected with insulating protective layer to the epitaxial structure side using isolation groove, effectively solve the problem that GaN epitaxial structure corrosion is caused due to KSF fluorescent powder hydrolysis in prior art.
[0005] To solve the above technical problems, the utility model provides a kind of light-emitting diode packaging structure, including package body and at least one LED chip being packaged in the package body, each the LED chip includes:
[0006] Substrate;
[0007] Epitaxial structure, disposed on the surface of the substrate, including buffer layer, first semiconductor layer, active layer and second semiconductor layer arranged in sequence;Wherein, the epitaxial structure side is further provided with the step from the second semiconductor layer to the first semiconductor layer.
[0008] a back reflector disposed on the back surface of the substrate;
[0009] a first isolation groove disposed on one side surface of the epitaxial structure and extending from the second semiconductor layer to the surface of the substrate;
[0010] a second isolation groove disposed on the other side surface of the epitaxial structure and extending from the first semiconductor layer to the surface of the substrate;
[0011] a current blocking layer disposed on the surface of the second semiconductor layer;
[0012] a transparent conductive layer disposed on the surface of the second semiconductor layer and extending to the surface of the current blocking layer;
[0013] a pad structure including a first pad and a second pad, the first pad being in contact with the transparent conductive layer and the surface of the second semiconductor layer after penetrating the current blocking layer, and the second pad being in contact with the surface of the first semiconductor layer on the step;
[0014] an insulating protective layer covering the first isolation groove, the second isolation groove, the pad structure and the transparent conductive layer;
[0015] wherein the package includes a package substrate bearing each of the LED chips and a package layer covering each of the LED chips, and the package layer is provided with KSF phosphor.
[0016] In an embodiment of the present application, the width of the first isolation groove and / or the width of the second isolation groove is 2-20 μm.
[0017] In an embodiment of the present application, the ratio of the width of the first isolation groove to the width of the second isolation groove is 0.1-10.
[0018] In an embodiment of the present application, the material of the package layer includes fluorescent glue or silicone.
[0019] In an embodiment of the present application, the KSF phosphor is settled at the position of each of the LED chips.
[0020] In an embodiment of the present application, the KSF phosphor is located at the middle and lower part of the package layer.
[0021] In an embodiment of the present application, the material of the insulating protective layer includes SiO2, Al2O3 or SiNx.
[0022] In an embodiment of the present application, the thickness of the insulating protective layer is 100-500 nm.
[0023] In an embodiment of the utility model, the insulating protective layer adopts double-layer structure, and alkali adsorbent is embedded in the middle of the double-layer structure.
[0024] In an embodiment of the utility model, the alkali adsorbent adopts zirconium oxide nanosphere.
[0025] Compared with the prior art, the above technical scheme of the utility model has the following advantages:
[0026] The LED packaging structure of the utility model, in the COB packaging containing KSF powder, adopts the deep isolation groove design to the LED chip, until the substrate layer. Meanwhile, through covering an insulating protective layer (such as SiO2, Al2O3, SiNx etc.) to the epitaxial structure side surface and the front of LED chip, effectively isolates the direct contact of water vapor and GaN epitaxial structure, prevents OH⁻ plasma and GaN material from reacting, protects the epitaxial structure from corrosion;In addition, the width of the isolation groove is designed between 2~20 μm, and the width ratio of the first isolation groove and the second isolation groove is controlled between 0.1~10, which ensures the isolation effect while maintaining the overall performance of the packaging;The thickness of the insulating protective layer is controlled between 100~500 nanometers, which not only ensures the effective protection effect, but also does not significantly affect the optical performance of LED. Through the above technical scheme, the utility model not only effectively prevents the corrosion of harmful ions generated after the hydrolysis of KSF powder to GaN epitaxial structure, but also improves the long-term stability and light efficiency of LED packaging. BRIEF DESCRIPTION OF DRAWINGS
[0027] In order to make the content of the utility model more easily understood, the utility model will be further explained in detail in the following according to the specific embodiments of the utility model and combining with the drawings.
[0028] Figure 1 It is the schematic diagram of the LED packaging structure in the utility model embodiment 1.
[0029] Figure 2 It is the schematic diagram of the LED chip in the LED packaging structure in the utility model embodiment 1.
[0030] Figure 3 It is the schematic diagram of the LED packaging structure in the utility model embodiment 2.
[0031] Figure 4 It is the schematic diagram of the LED chip in the LED packaging structure in the utility model embodiment 2.
[0032] EXPLANATION OF DRAWINGS IN THE SPECIFICATION:
[0033] 100, LED chip; 200, package; 300, package substrate; 400, package layer; 500, KSF phosphor;
[0034] 10, substrate;
[0035] 20, epitaxial structure; 21, buffer layer; 22, first semiconductor layer; 23, active layer; 24, second semiconductor layer; 25, step; 26a, first isolation groove; 26b, second isolation groove;
[0036] 30, back reflector;
[0037] 40, current blocking layer;
[0038] 50, transparent conductive layer;
[0039] 60a, first pad; 60b, second pad;
[0040] 70, insulating protective layer;
[0041] 80, zirconium oxide nanosphere;
[0042] 90, wire. DETAILED DESCRIPTION
[0043] The utility model will be further explained in connection with the drawings and specific embodiments, so that the person skilled in the art can better understand the utility model and can be implemented, but the embodiment is not as the limitation of the utility model.
[0044] In the utility model, if the direction (up, down, left, right, front and back) is described, it is only for the convenience of describing the technical scheme of the utility model, and is not indicated or implied that the indicated technical feature must have a specific orientation, structure and operation, so it cannot be understood as the limitation of the utility model.
[0045] In the utility model, the meaning of "several" is one or more, and the meaning of "multiple" is two or more, "more than", "less than", "exceed" and the like are not included in the number; "above", "below", "within" and the like are included in the number. In the description of the utility model, if "first" and "second" are described, they are only used for distinguishing technical features for the purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.
[0046] In this utility model, unless otherwise explicitly defined, terms such as "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model based on the specific content of the technical solution.
[0047] Example 1
[0048] Reference Figure 1 , Figure 2 As shown, this embodiment provides a light-emitting diode (LED) packaging structure, including a package body 200 and at least one LED chip 100 packaged in the package body 200. Each LED chip 100 includes:
[0049] Substrate 10;
[0050] An epitaxial structure 20 (GaN epitaxy) is disposed on the surface of the substrate 10, including a buffer layer 21, a first semiconductor layer 22, an active layer 23, and a second semiconductor layer 24 disposed sequentially; wherein, the epitaxial structure 20 also has a step 25 extending from the second semiconductor layer 24 to the first semiconductor layer 22 on its side.
[0051] A rear reflector 30 is disposed on the back side of the substrate 10;
[0052] A first isolation trench 26a is disposed on one side of the epitaxial structure 20 and extends from the second semiconductor layer 24 to the surface of the substrate 10;
[0053] The second isolation trench 26b is disposed on the other side of the epitaxial structure 20 and extends from the first semiconductor layer 22 to the surface of the substrate 10;
[0054] A current blocking layer 40 is disposed on the surface of the second semiconductor layer 24;
[0055] A transparent conductive layer 50 is disposed on the surface of the second semiconductor layer 24 and extends to the surface of the current blocking layer 40;
[0056] The pad structure includes a first pad 60a and a second pad 60b. The first pad 60a contacts the transparent conductive layer 50 and penetrates the current blocking layer 40 before contacting the surface of the second semiconductor layer 24. The second pad 60b contacts the surface of the first semiconductor layer 22 located on the step 25.
[0057] An insulating protective layer 70 covers the first isolation groove 26a, the second isolation groove 26b, the pad structure, and the transparent conductive layer 50.
[0058] The package 200 includes a package substrate 300 carrying each LED chip 100 and a package layer 400 covering each LED chip 100, and the package layer 400 is provided with KSF fluorescent powder 500. The first pad 60a and the second pad 60b each have a solder joint lead wire 90 to the package substrate 300.
[0059] Specifically, the width of the first isolation groove 26a and / or the width of the second isolation groove 26b is 2-20 μm, and the ratio of the width (W1) of the first isolation groove 26a to the width (W2) of the second isolation groove 26b is 0.1-10. The isolation effect is ensured while maintaining the overall performance of the package.
[0060] Specifically, the material of the package layer 400 includes fluorescent glue or silicone glue.
[0061] Specifically, the KSF fluorescent powder 500 is settled at the position of each LED chip 100, or the KSF fluorescent powder 500 is located at the middle or lower part of the package layer 400.
[0062] Specifically, the material of the insulating protective layer 70 includes SiO2, Al2O3, or SiNx, and the thickness of the insulating protective layer 70 is 100-500 nm. The effective protection effect is ensured without significantly affecting the optical performance of the LED.
[0063] In the COB package containing KSF powder, a deep isolation groove design is adopted for the LED chip 100, which reaches the substrate 10 layer. At the same time, an insulating protective layer 70 is covered on the side and front of the epitaxial structure 20 of the LED chip 100, which effectively isolates the direct contact of water vapor and GaN epitaxial structure 20, prevents the reaction of OH⁻ plasma and GaN material, and protects the epitaxial structure 20 from corrosion.
[0064] Embodiment 2
[0065] Referring to Figure 3 , Figure 4 The embodiment provides a light emitting diode package structure, which is different from embodiment 1 in that the insulating protective layer 70 of the embodiment has a double-layer structure, and an alkali adsorbent is embedded in the middle of the double-layer structure. Specifically, the alkali adsorbent is a zirconia nanosphere 80. The rest of the structure is the same as that of embodiment 1.
[0066] The base adsorbent (such as zirconium oxide nanospheres) can effectively adsorb or neutralize the alkaline substances (such as OH⁻ ions) released by the encapsulating material (such as KSF powder hydrolysis). After embedding the base adsorbent, the double-layer insulation protective layer can further reduce the possibility of water vapor or alkaline substances penetrating the insulation layer. Even if a small amount of OH⁻ or other alkaline substances penetrates the first layer of insulation protective layer, it will be neutralized by the adsorbent before reaching the second layer of insulation layer, thereby preventing it from chemically reacting with the GaN epitaxy.
[0067] Therefore, the embodiment can further reduce the penetration of alkaline substances generated by KSF powder hydrolysis through the insulation layer to corrode the GaN epitaxy by the double-layer insulation protective layer 70, greatly reducing the risk of corrosive substances damaging the GaN epitaxial structure, and significantly improving the long-term stability and reliability of the LED package.
[0068] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, and they should be included in the scope of the claims of the present application.
Claims
1. A light emitting diode package structure, characterized by, The package (200) comprises at least one LED chip (100) encapsulated in the package (200), each LED chip (100) comprising: a substrate (10); an epitaxial structure (20) disposed on the surface of the substrate (10) and comprising a buffer layer (21), a first semiconductor layer (22), an active layer (23) and a second semiconductor layer (24) disposed in sequence; wherein the side surface of the epitaxial structure (20) is further provided with a step (25) extending from the second semiconductor layer (24) to the first semiconductor layer (22); a back reflector (30) disposed on the back surface of the substrate (10); a first isolation groove (26a) disposed on one side surface of the epitaxial structure (20) and extending from the second semiconductor layer (24) to the surface of the substrate (10); a second isolation groove (26b) disposed on the other side surface of the epitaxial structure (20) and extending from the first semiconductor layer (22) to the surface of the substrate (10); a current blocking layer (40) disposed on the surface of the second semiconductor layer (24); a transparent conductive layer (50) disposed on the surface of the second semiconductor layer (24) and extending to the surface of the current blocking layer (40); a pad structure comprising a first pad (60a) and a second pad (60b), the first pad (60a) being in contact with the transparent conductive layer (50) and the surface of the second semiconductor layer (24) after penetrating through the current blocking layer (40), and the second pad (60b) being in contact with the surface of the first semiconductor layer (22) on the step (25); an insulating protective layer (70) covering the first isolation groove (26a), the second isolation groove (26b), the pad structure and the transparent conductive layer (50); wherein the package (200) comprises a package substrate (300) carrying each LED chip (100) and a package layer (400) covering each LED chip (100), and the package layer (400) is provided with KSF phosphor (500).
2. The light emitting diode package structure of claim 1, wherein the first and second electrodes are formed on the first and second surfaces of the substrate, respectively. The width of the first isolation groove (26a) and / or the width of the second isolation groove (26b) is 2-20 μm.
3. The LED package structure of claim 1, wherein the phosphor layer is formed on the LED chip. The ratio of the width of the first isolation groove (26a) to the width of the second isolation groove (26b) is 0.1-10.
4. The LED package structure of claim 1, wherein the phosphor layer is formed on the LED chip. The material of the package layer (400) comprises fluorescent glue or silicone glue.
5. The LED package structure of claim 1, wherein the phosphor layer is formed on the LED chip. The KSF phosphor (500) is settled at the position of each LED chip (100).
6. The LED package structure of claim 1, wherein the phosphor layer is formed on the LED chip. The KSF phosphor (500) is located at the middle and lower part of the package layer (400).
7. The LED package structure of claim 1, wherein the phosphor layer is formed on the LED chip. The material of the insulating protective layer (70) comprises SiO2, Al2O3 or SiNx.
8. The LED package structure of claim 1, wherein the phosphor layer is formed on the LED chip. The thickness of the insulating protective layer (70) is 100-500 nm.
9. The LED package structure of claim 1, wherein the phosphor layer is formed on the LED chip. The insulating protective layer (70) adopts a double-layer structure, and an alkali adsorbent is embedded in the middle of the double-layer structure.
10. The light emitting diode package structure of claim 9, wherein the phosphor layer is formed on the surface of the light emitting diode chip. The alkali adsorbent adopts zirconia nanospheres (80).