Near-inorganic packaging structure of deep ultraviolet LED

Abstract

The invention provides a near-inorganic packaging structure of a deep ultraviolet LED, which comprises a packaging bracket, an optical lens and at least one deep ultraviolet LED chip, and is characterized in that the packaging bracket comprises a supporting substrate and a box dam, the box dam is annularly arranged at the edge of the supporting substrate, the center of the supporting substrate is provided with a placement groove, the deep ultraviolet LED chip is fixed at the bottom of the placement groove, and the deep ultraviolet LED chip is fixed at the bottom of the placement groove. The optical lens is located above the supporting substrate and completely covers the placing groove, a sealing material layer is sprayed on a peripheral supporting plane of the supporting substrate, and at least one part of the sealing material layer is clamped between the box dam and the optical lens; the sealing material layer comprises at least two inorganic adhesive layers and at least one waterproof coating, the waterproof coating is located between the two adjacent inorganic adhesive layers, and the waterproof coating is formed by spraying and curing a waterborne polyurethane high polymer material; the near-inorganic packaging structure provided by the invention not only overcomes the defects of the existing semi-inorganic and inorganic packaging, but also has multiple advantages of ultraviolet resistance, water resistance, simple process and controllable cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor optoelectronics, and in particular to a near-inorganic packaging structure of a deep ultraviolet LED. BACKGROUND

[0002] A deep ultraviolet LED (Light-Emitting Diode) is a light source with a wavelength of 200nm-280nm, which has a good sterilization function and a very broad application prospect. The current packaging methods of deep ultraviolet LEDs are mainly semi-inorganic packaging and inorganic packaging. The main difference between semi-inorganic packaging and inorganic packaging is the fixing method of the lens. Semi-inorganic packaging uses traditional organic glue to bond and seal the lens and the support, while inorganic packaging requires metalizing solder on the edge of the lens first, and then using laser sealing and bonding. However, the above two packaging processes have their own advantages and disadvantages: the advantages of semi-inorganic packaging are mature technology, easy mass production, and very low cost, and the disadvantage is that when the ultraviolet energy reaches a certain intensity, the adhesive will yellow and crack; the advantages of inorganic packaging are high reliability and no influence of ultraviolet radiation, and the disadvantages are relatively complex process, high cost, and low efficiency.

[0003] The core problem of the existing deep ultraviolet LED packaging technology is that the organic glue of semi-inorganic packaging is easily damaged by ultraviolet light, and the process of inorganic packaging is complex, the cost is high, and both cannot achieve a balance between reliability, cost and production efficiency, which limits the large-scale application of deep ultraviolet LEDs (especially in civilian scenarios).

[0004] Therefore, there is an urgent need for a near-inorganic packaging structure of a deep ultraviolet LED to solve the above technical problems. SUMMARY

[0005] The purpose of the present application is to provide a near-inorganic packaging structure of a deep ultraviolet LED, which solves the technical problem that the packaging structure of the prior art deep ultraviolet LED is difficult to reduce the packaging cost while having high packaging reliability.

[0006] To solve the above technical problems, the present application provides a near-inorganic packaging structure of a deep ultraviolet LED, which comprises a packaging support, an optical lens and at least one deep ultraviolet LED chip, the packaging support comprises a support substrate and a dam, the dam is annularly arranged at the edge of the support substrate, a placing groove is formed at the center of the support substrate, the deep ultraviolet LED chip is fixed at the bottom of the placing groove, and the optical lens is located above the support substrate and completely covers the placing groove. The outer periphery support plane of the support substrate is sprayed with a sealing material layer, and at least part of the sealing material layer is clamped between the dam and the optical lens; the sealing material layer comprises at least two inorganic adhesive layers and at least one waterproof coating layer, the waterproof coating layer is located between the two adjacent inorganic adhesive layers, and the waterproof coating layer is formed by spraying and curing of a water-based polyurethane polymer material.

[0007] Preferably, the optical lens is arranged on the outer periphery support plane of the support substrate, and the optical lens and the support substrate combine to form a first sealed cavity, and the deep ultraviolet LED chip is located in the first sealed cavity.

[0008] Preferably, the inner wall of the dam, the outer surface of the optical lens, and the outer periphery support plane of the support substrate form an annular groove, and the sealing material layer is filled in the annular groove.

[0009] Preferably, at least part of the bottom surface of the optical lens is in contact with the sealing material layer, and the optical lens, part of the sealing material layer, and the support substrate combine to form a second sealed cavity, and the deep ultraviolet LED chip is located in the second sealed cavity.

[0010] Preferably, at least part of the bottom surface of the optical lens is in contact with the inorganic adhesive layer in the sealing material layer.

[0011] Preferably, the inorganic adhesive layer is formed by mixing and curing of a non-transparent inorganic adhesive and water, and the inorganic adhesive comprises at least one of a phosphate, a silicate, a borate, a sulfate, and a metal oxide.

[0012] Preferably, the sealing material layer comprises three inorganic adhesive layers and two waterproof coating layers, and the thickness of the waterproof coating layer is less than the thickness of the inorganic adhesive layer.

[0013] Preferably, the depth of the placement groove is greater than or equal to the thickness of the deep ultraviolet LED chip.

[0014] Preferably, the transmittance of the optical lens to ultraviolet light is ≥70%.

[0015] Preferably, the spherical shape of the optical lens comprises any one of a planar shape, a hemispherical shape, an ellipsoidal shape, a Fresnel spherical shape, and a polyhedral spherical shape.

[0016] The beneficial effects of the present application are: different from the prior art, the present application provides a near-inorganic packaging structure of deep ultraviolet LED, including a packaging support, an optical lens and at least one deep ultraviolet LED chip, the packaging support includes a support substrate and a dam, the dam is annularly arranged at the edge of the support substrate, a placing groove is formed at the center of the support substrate, the deep ultraviolet LED chip is fixed to the bottom of the placing groove, and the optical lens is located above the support substrate and completely covers the placing groove, wherein a sealing material layer is sprayed on the peripheral support plane of the support substrate, and at least part of the sealing material layer is clamped between the dam and the optical lens; the sealing material layer includes at least two inorganic adhesive layers and at least one waterproof coating layer, the waterproof coating layer is located between the two adjacent inorganic adhesive layers, and the waterproof coating layer includes a water-based polyurethane polymer material; in the present application, the sealing material layer adopts a laminated structure of "at least two inorganic adhesive layers + at least one water-based polyurethane waterproof coating layer", wherein the inorganic adhesive layer avoids the problem of yellowing and cracking failure of traditional organic glue in the presence of ultraviolet light due to its own ultraviolet resistance, and guarantees the bonding strength and stability of the packaging structure under deep ultraviolet irradiation; and the water-based polyurethane waterproof coating layer can effectively isolate moisture and prevent water vapor from eroding the deep ultraviolet LED chip by means of a process similar to epitaxial growth, thereby further improving the waterproof performance and providing good environmental protection for the chip; in addition, the structure is realized by a spraying process, which simplifies the process flow compared with the complex laser sealing and bonding and metallization treatment in inorganic packaging, and is expected to reduce production cost and improve production efficiency. Therefore, the near-inorganic packaging structure not only overcomes the shortcomings of existing semi-inorganic and inorganic packaging, but also realizes the multiple advantages of ultraviolet resistance, waterproofness, simple process and controllable cost, can provide reliable protection for the deep ultraviolet LED chip, and expand its application in high-reliability fields such as medical disinfection and water treatment. BRIEF DESCRIPTION OF DRAWINGS Figure 1 is a structural schematic diagram of the near-inorganic packaging structure of deep ultraviolet LED provided by the embodiment 1 of the present application; Figure 2 is a structural schematic diagram of the near-inorganic packaging structure of deep ultraviolet LED provided by the embodiment 2 of the present application; In the brief description of drawings: 100 is a near-inorganic packaging structure of deep ultraviolet LED; 10 is a packaging support; 11 is a support substrate; 12 is a dam; 111 is a placing groove; 20 is a deep ultraviolet LED chip; 30 is an optical lens; 40 is a sealing material layer; 401 is an annular groove; 41 is an inorganic adhesive layer; and 42 is a waterproof coating layer. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0018] In view of the deficiencies of the prior art, the present application provides a near-inorganic packaging structure of a deep ultraviolet LED, which not only overcomes the shortcomings of the existing semi-inorganic and inorganic packaging, but also realizes multiple advantages of ultraviolet resistance, waterproofness, simple process and controllable cost, can provide reliable protection for the deep ultraviolet LED chip, and expand its application in the fields of high reliability requirements such as medical disinfection and water treatment. Because this near-inorganic packaging structure is mainly inorganic material, only part of the interlayer uses organic sealant, so it is called near-inorganic packaging process.

[0019] The technical solutions of the present application will be described in conjunction with specific embodiments.

[0020] Embodiment 1 Please refer to Figure 1 , Figure 1 The structure diagram of the near-inorganic packaging structure of a deep ultraviolet LED provided by Embodiment 1 of the present application; wherein the near-inorganic packaging structure 100 of the deep ultraviolet LED comprises a packaging support 10, an optical lens 30 and at least one deep ultraviolet LED chip 20, the packaging support 10 comprises a support substrate 11 and a dam 12, the dam 12 is annularly arranged at the edge of the support substrate 11 and is integrally formed with the support substrate 11, a placing groove 111 is formed at the center of the support substrate 11, the deep ultraviolet LED chip 20 is fixed to the bottom of the placing groove 111, and the optical lens 30 is located above the support substrate 11 and completely covers the placing groove 111. Wherein, the outer peripheral support plane of the support substrate 11 is sprayed with a sealing material layer 40, at least a part of the sealing material layer 40 is clamped between the dam 12 and the optical lens 30; the sealing material layer 40 comprises at least two inorganic adhesive layers 41 and at least one waterproof coating layer 42, the waterproof coating layer 42 is located between the adjacent two inorganic adhesive layers 41, and the waterproof coating layer 42 is formed by spraying and curing of a water-based polyurethane polymer material.

[0021] Specifically, the deep ultraviolet LED near-inorganic packaging structure 100 realizes the dual optimization of performance and process through unique design and material combination: in terms of structure, the packaging support 10, the optical lens 30 and the deep ultraviolet LED chip 20 cooperate to form a basic frame, and the dam 12 and the placement groove 111 guarantee the fixation of the chip and the concentration of the light path; in terms of material, the sealing material layer 40 adopts a laminated structure of "at least two layers of inorganic adhesive layers 41 + at least one layer of water-based polyurethane waterproof coating 42", and the inorganic adhesive layer 41 avoids the problem of yellowing and cracking of organic glue in traditional semi-inorganic packaging due to ultraviolet radiation, thereby guaranteeing the bonding strength and stability of the packaging structure under deep ultraviolet radiation; the water-based polyurethane waterproof coating 42 is effectively isolated after being sprayed and cured, preventing water vapor from eroding the chip and further improving the waterproof performance; compared with the complex laser sealing and bonding process of traditional inorganic packaging, the spraying process simplifies the process and reduces the cost.

[0022] In this embodiment 1, the material of the support substrate 11 can be any one of aluminum nitride ceramic, aluminum oxide ceramic and zirconium oxide ceramic. The support substrate 11 is used to support the optical lens 30 and fix the deep ultraviolet LED chip 20.

[0023] In this embodiment 1, the optical lens 30 is arranged on the peripheral support plane of the support substrate 11, and the optical lens 30 and the support substrate 11 form a first sealed cavity, and the deep ultraviolet LED chip 20 is located in the first sealed cavity; wherein this design can realize multiple protection through physical sealing: on the one hand, the first sealed cavity and the sealing material layer 40 form a "structure + material" double sealing system, which can isolate the invasion of external water vapor, dust and other pollutants, and avoid the performance degradation of the deep ultraviolet LED chip 20 due to environmental erosion; on the other hand, the first sealed cavity can reduce the direct irradiation of ultraviolet light on the packaging material, cooperate with the ultraviolet resistance of the inorganic adhesive layer 41, further inhibit the yellowing and cracking of the sealing material, and improve the reliability of the device under high-intensity ultraviolet radiation; in addition, the first sealed cavity structure is sealed by spraying process without complex laser sealing, which simplifies the process and reduces the cost, and is suitable for medical disinfection, water treatment and other scenes with high requirements for sealing and durability.

[0024] In the present embodiment 1, the inner wall of the dam 12, the outer surface of the optical lens 30 and the peripheral support plane of the supporting substrate 11 form an annular groove, and the sealing material layer 40 is filled in the annular groove 401; wherein, the geometric structure of the annular groove 401 forms a physical limit frame, so that the sealing material layer 40 can be evenly distributed and the thickness can be controlled during filling, avoiding the problems of glue overflow or uneven thickness in the traditional glue coating process, thereby improving the consistency of the seal; at the same time, the annular closed space of the annular groove 401 and the laminated structure of the sealing material (the inorganic layer is UV-resistant and the water-based polyurethane is waterproof) form a double protection system of "space + material" - the inorganic adhesive layer 41 is in the annular groove 401. The annular groove 401 directly resists the damage of ultraviolet rays to the sealing interface. The water-based polyurethane coating is filled between the inorganic layers, which can effectively block water vapor from penetrating into the first closed cavity along the gap of the annular groove 401, thereby preventing the deep ultraviolet LED chip 20 from becoming moisture-damaged and failing. In addition, the annular groove 401, as a prefabricated structure, can guide the precise deposition of sealing materials in the spraying process and reduce material waste. Compared with the laser sealing of traditional inorganic packaging, this structure simplifies the process steps through "groove limiting + spray filling", reduces the equipment precision requirements, and optimizes the production cost while improving the packaging reliability. It is suitable for deep ultraviolet application scenarios that require high sealing and weather resistance.

[0025] In this first embodiment, the inorganic adhesive layer 41 is formed by curing a mixture of a non-transparent inorganic adhesive and water. The inorganic adhesive includes at least one of a phosphate, a silicate, a borate, a sulfate, and a metal oxide. Because the water-based polyurethane and the inorganic salt have good wettability, the waterproof coating 42 penetrates into the inorganic salt, filling the pores within the inorganic salt to form a waterproof layer.

[0026] Specifically, the inorganic adhesive layer 41 is formed by curing an inorganic adhesive such as phosphate or silicate with water. The inorganic material itself possesses excellent UV aging resistance, preventing the yellowing and cracking problems of traditional organic glues under deep UV radiation, thereby ensuring the long-term reliability of the packaging structure. Microscopic pores exist within the cured inorganic adhesive layer 41. Due to its excellent wettability with inorganic salts, the water-based polyurethane can penetrate into these pores to form a continuous waterproof layer. This "penetration-filling" mechanism not only eliminates the pore defects of the inorganic layer but also enhances the overall density of the sealing material layer 40 through the polymer network of the water-based polyurethane, effectively blocking the intrusion of environmental pollutants such as water vapor and oxygen into the first sealed cavity. Furthermore, this material system eliminates the need for complex metallization or laser sealing processes. Simply by spray curing, it achieves the dual protection of "inorganic UV resistance + water-based waterproofing," simplifying the packaging process while reducing costs. It is suitable for use in applications such as medical disinfection and food preservation that require stringent weather resistance and sealing properties.

[0027] In the present embodiment 1, the sealing material layer 40 comprises three layers of inorganic adhesive layers 41 and two layers of waterproof coating layers 42, the thickness of the waterproof coating layer 42 is less than the thickness of the inorganic adhesive layer 41; wherein the three layers of inorganic adhesive layers 41 (containing phosphate, silicate and other UV-resistant materials) can form a thicker UV-resistant barrier, which can improve the UV aging resistance by about 30% compared with the traditional two-layer structure, and can effectively inhibit the yellowing and cracking of the material under deep UV irradiation; the two layers of water-based polyurethane waterproof coating layers 42 are sandwiched between the inorganic adhesive layers 41, which can penetrate and fill the pores of the inorganic adhesive layer 41 with a thin thickness (such as 1 / 3 of the thickness of the inorganic layer) by using its good infiltration with inorganic salt, forming a composite dense structure of "inorganic skeleton + polymer filling", which can further reduce the water vapor permeability compared with a single waterproof coating layer 42. The structure is designed by "multi-layer inorganic UV-resistant enhancement + thin-layer waterproof reinforced sealing", which can ensure the reliability of packaging while avoiding the increase of process complexity caused by the over-thickness of the coating layer. The spraying process can realize the precise deposition of each layer of material, and the production cost is greatly reduced compared with the all-inorganic packaging, which is suitable for medical sterilization, air purification and other scenes that require long-term high-intensity UV radiation.

[0028] In the present embodiment 1, the depth of the placement groove 111 is greater than or equal to the thickness of the deep UV LED chip 20; wherein when the depth of the placement groove 111 is greater than or equal to the thickness of the deep UV LED chip 20, the bottom of the deep UV LED chip 20 is in full contact with the bottom of the groove, which ensures the stability of fixation and provides a more direct heat conduction path for heat dissipation of the deep UV LED chip 20 (such as heat dissipation through the metal layer on the support substrate 11), avoiding the increase of junction temperature of the deep UV LED chip 20 caused by heat accumulation, which affects the luminous efficiency; in addition, the depth-adapted placement groove 111 can make the chip completely embedded in the groove, and the first sealed cavity formed after the optical lens 30 covers can better isolate external impact and prevent the deep UV LED chip 20 from being damaged by mechanical vibration or collision; if the depth of the placement groove 111 is greater than the thickness of the chip, the remaining space in the groove can be filled with heat-conducting glue or inert gas, further improving the heat dissipation performance and environmental sealing performance, and cooperating with the UV-resistant and waterproof design of the sealing material layer 40, the structure can provide a stable working environment for the chip in high-reliability scenes such as medical disinfection and underwater UV sterilization, and prolong the service life of the device.

[0029] In the present embodiment 1, the transmittance of the optical lens 30 to the ultraviolet band light is greater than or equal to 70%; the spherical shape of the optical lens 30 comprises any one of a plane shape, a hemispherical surface, an ellipsoidal surface, a Fresnel spherical surface and a polyhedral spherical surface.

[0030] Specifically, the UV band light transmittance of ≥70% ensures that the deep ultraviolet light can be efficiently emitted, avoiding excessive absorption and scattering of the lens to the ultraviolet light, thereby reducing the sterilization and disinfection effect of the deep ultraviolet LED, and effectively maintaining the radiation intensity and performance of the light source. On the other hand, the diversified shape selection of the planar, hemispherical, ellipsoidal, Fresnel spherical and polyhedral spherical surfaces provides flexibility for optical design. The planar lens is suitable for scenarios that do not require high light emission angle and pursue thinness. The hemispherical and ellipsoidal lenses can realize light convergence or divergence, accurately control the propagation direction of light, and meet the high-intensity illumination requirements of specific areas. The Fresnel spherical and polyhedral spherical lenses can optimize the light field distribution through special surface structures, improve the light energy utilization rate, realize uniform light emission or specific spot shape, and thus adapt the packaging structure to the different requirements of medical equipment, air purification, water treatment and other fields for the output characteristics of ultraviolet light.

[0031] In this embodiment 1, the deep ultraviolet LED chip 20 is preferably a chip emitting light in the 200-280 nm band (UVC chip), and its core function is to generate ultraviolet light with strong sterilization and disinfection ability through electrical excitation, which has unique value in the fields of public health, medical health, etc.

[0032] Correspondingly, the preparation process of the deep ultraviolet LED chip 20 provided in this embodiment 1 is as follows: Step one, fix the UVC chip into the placement slot 111 of the support substrate 11 through the die bonding equipment, and then place the optical lens 30 on the peripheral support plane of the support substrate 11; after placing the optical lens 30, the inner wall of the dam 12, the outer surface of the optical lens 30 and the peripheral support plane of the support substrate 11 form an annular groove 401, which can be used as a mold for subsequent spraying of inorganic adhesive and waterproof coating 42.

[0033] Step two, spray inorganic adhesive of non-transparent medium inside the annular groove 401, and after the inorganic adhesive is cured (curing temperature is 10-180°C), spray waterproof coating 42 on the surface, which is mainly water-based polyurethane. Since the water-based polyurethane and inorganic salt have good wettability, the waterproof coating 42 will penetrate into the inorganic salt and fill the pores inside the inorganic salt to form the waterproof coating 42.

[0034] Step three, repeat step two to spray inorganic adhesive on the surface of the waterproof coating 42, which is to protect the waterproof coating 42 from ultraviolet radiation. Such repeated spraying operation is similar to epitaxial growth, and finally forms a sealing material layer 40 with a laminated structure. The spraying number of inorganic adhesive is M, M≥2; the spraying number of waterproof coating 42 is N, N=M-1 (M=3 in this embodiment 1).

[0035] Embodiment 2: Please refer toFigure 2 , Figure 2 Figure 2 is a structural schematic diagram of a near-inorganic encapsulation structure of a deep ultraviolet LED provided by Embodiment 2 of the present application; the near-inorganic encapsulation structure of the deep ultraviolet LED provided by Embodiment 2 of the present application is substantially the same as the near-inorganic encapsulation structure of the deep ultraviolet LED provided by Embodiment 1 of the present application, and the only difference is that: at least a portion of the bottom surface of the optical lens 30 is in contact with the sealing material layer 40, and the optical lens 30, the partial sealing material layer 40 and the support substrate 11 combine to form a second closed cavity, and the deep ultraviolet LED chip 20 is located in the second closed cavity; wherein at least a portion of the bottom surface of the optical lens 30 is in contact with the inorganic adhesive layer 41 in the sealing material layer 40.

[0036] Specifically, compared with the first closed cavity, the second closed cavity of Embodiment 2 realizes the triple improvement of sealing, optical and structural performance through the design of direct contact between the bottom surface of the optical lens 30 and the inorganic adhesive layer 41: the inorganic adhesive layer 41 acts as a transition layer, and the double protection of the ultraviolet-resistant material and the water-based polyurethane coating greatly reduces the water vapor permeability, and the inorganic adhesive layer 41 with low surface roughness can reduce ultraviolet light scattering loss and improve light transmittance; in addition, the thermal expansion coefficient of the inorganic layer can reduce the environmental stress of the near-encapsulation structure, and comprehensively enhance the reliability of the deep ultraviolet LED in complex environments.

[0037] Correspondingly, the preparation process of the deep ultraviolet LED chip 20 provided by Embodiment 2 of the present application is as follows: Step one, fix the UVC chip to the placement groove 111 of the support substrate 11 through the die bonding equipment, and then place the optical lens 30 on the peripheral support plane of the support substrate 11; after the optical lens 30 is placed, the inner wall of the dam 12, the outer surface of the optical lens 30 and the peripheral support plane of the support substrate 11 form an annular groove 401, which can be used as a mold for subsequent spraying of inorganic adhesive and waterproof coating 42.

[0038] Step two, spray inorganic adhesive on the dam 12 of the support substrate 11, then place the optical lens 30 above the inorganic adhesive, and give a certain pressure, so that the inorganic adhesive is wrapped around the optical lens 30 and recessed in the inorganic adhesive, then cure the inorganic adhesive at 10-180℃ to obtain an inorganic adhesive layer.

[0039] Step three, spray a waterproof coating 42 on the surface of the inorganic adhesive layer, and the waterproof coating 42 is mainly water-based polyurethane. Because the water-based polyurethane and the inorganic salt have good wettability, the waterproof coating 42 will penetrate into the inorganic salt and fill the pores in the inorganic salt to form a waterproof coating 42.

[0040] In step 4, repeat step 2 to spray an inorganic adhesive onto the surface of waterproof coating 42 to protect it from UV radiation. This alternating spraying process is repeated, similar to epitaxial growth, ultimately forming a laminated sealing material layer 40. The inorganic adhesive is sprayed M times, M ≥ 2; the waterproof coating 42 is sprayed N times, N = M - 1 (M = 3 in Example 2).

[0041] In summary, different from the prior art, the near-inorganic packaging structure 100 of the deep ultraviolet LED provided by the present invention uses an inorganic adhesive to bond the lens after the deep ultraviolet LED chip 20 and the supporting substrate 11 are eutectic welded, and at the same time, a water-based waterproof coating 42 is sprayed on the surface of the inorganic adhesive. This waterproof coating 42 can penetrate into the pores of the inorganic adhesive to form a sealed waterproof structure, and then the inorganic adhesive is sprayed again on the waterproof coating 42. The inorganic adhesive protects the waterproof coating 42 to prevent ultraviolet radiation. Among them, the waterproof coating 42 is a water-based polyurethane polymer material, which is sprayed in layers through a process similar to epitaxial growth, and finally forms a reliable near-inorganic package. The bonding strength is not affected under ultraviolet radiation. At the same time, the structure also has very good waterproof properties, providing good protection for the ultraviolet LED chip.

[0042] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For any details not described in individual embodiments, reference may be made to the description in other embodiments.

[0043] The above embodiments merely illustrate the implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A near-inorganic encapsulation structure for a deep ultraviolet LED, comprising: The package support, the optical lens and at least one deep ultraviolet LED chip are included, the package support includes a support substrate and a dam, the dam is annularly arranged at the edge of the support substrate, a placing slot is arranged at the center of the support substrate, the deep ultraviolet LED chip is fixed to the bottom of the placing slot, and the optical lens is located above the support substrate and covers the placing slot completely. The outer peripheral support plane of the support substrate is sprayed with a sealing material layer, at least a part of the sealing material layer is clamped between the dam and the optical lens, the sealing material layer includes at least two inorganic adhesive layers and at least one waterproof coating layer, the waterproof coating layer is located between two adjacent inorganic adhesive layers, and the waterproof coating layer is formed by spraying and curing of a water-based polyurethane polymer material.

2. The near-inorganic encapsulation structure of a deep ultraviolet LED of claim 1, wherein, The optical lens is arranged on the outer peripheral support plane of the support substrate, and the optical lens and the support substrate combine to form a first closed cavity, and the deep ultraviolet LED chip is located in the first closed cavity.

3. The near-inorganic encapsulation structure of a deep ultraviolet LED of claim 2, wherein, The inner wall of the dam, the outer surface of the optical lens and the outer peripheral support plane of the support substrate form an annular groove, and the sealing material layer is filled in the annular groove.

4. The near-inorganic encapsulation structure of a deep ultraviolet LED of claim 1, wherein, At least a part of the bottom surface of the optical lens is in contact with the sealing material layer, the optical lens, part of the sealing material layer and the support substrate combine to form a second closed cavity, and the deep ultraviolet LED chip is located in the second closed cavity.

5. The near-inorganic encapsulation structure of a deep ultraviolet LED of claim 4, wherein, At least a part of the bottom surface of the optical lens is in contact with the inorganic adhesive layer in the sealing material layer.

6. The near-inorganic encapsulation structure of a deep ultraviolet LED according to claim 1 or 4, wherein, The inorganic adhesive layer is formed by mixing and curing of a non-transparent inorganic adhesive and water, and the inorganic adhesive includes at least one of a phosphate, a silicate, a borate, a sulfate and a metal oxide.

7. The near-inorganic encapsulation structure of a deep ultraviolet LED of claim 6, wherein, The sealing material layer includes three inorganic adhesive layers and two waterproof coating layers, and the thickness of the waterproof coating layer is less than the thickness of the inorganic adhesive layer.

8. The near-inorganic encapsulation structure of a DUV LED of claim 6, wherein, The depth of the placing slot is greater than or equal to the thickness of the deep ultraviolet LED chip.

9. The near-inorganic encapsulation structure of a DUV LED of claim 6, wherein, The transmittance of the optical lens to ultraviolet light is greater than or equal to 70%.

10. The near-inorganic encapsulation structure of a deep ultraviolet LED of claim 6, wherein, The spherical shape of the optical lens includes any one of a plane shape, a half-spherical shape, an ellipsoidal shape, a Fresnel spherical shape and a polyhedral spherical shape.

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