CN116632144A

CN116632144A - Deep ultraviolet LED luminous element and preparation method thereof

Info

Publication number: CN116632144A
Application number: CN202310515334.1A
Authority: CN
Inventors: 宋慨; 姚禹; 郑远志; 成旭东; 康建; 陈向东
Original assignee: Yuanrong Photoelectric Technology Co ltd; Maanshan Jiesheng Semiconductor Co ltd
Current assignee: Yuanrong Photoelectric Technology Co ltd; Maanshan Jiesheng Semiconductor Co ltd
Priority date: 2023-05-09
Filing date: 2023-05-09
Publication date: 2023-08-22

Abstract

The invention discloses a deep ultraviolet LED light-emitting element and a preparation method thereof. The bracket is provided with a containing groove. The deep ultraviolet LED chip is fixed in the accommodating groove, and the light emitting side of the deep ultraviolet LED chip faces the notch of the accommodating groove. The first lens at least covers the light emitting side of the deep ultraviolet LED chip, the ultraviolet transmittance of the first lens is not lower than 50%, and the refractive index of the first lens is larger than 1 and smaller than that of the deep ultraviolet LED chip. The second lens is fixed on the bracket and covers the notch of the accommodating groove. The conductive component is arranged on the bracket and comprises a positive conductive piece for connecting with the positive electrode of the power supply and a negative conductive piece for connecting with the negative electrode of the power supply. Compared with the prior art, the deep ultraviolet LED light-emitting element and the preparation method thereof can improve the light-emitting efficiency and reliability of the deep ultraviolet LED light-emitting element.

Description

Deep ultraviolet LED luminous element and preparation method thereof

Technical Field

The invention relates to the technical field of LED luminous elements, in particular to a deep ultraviolet LED luminous element and a preparation method thereof.

Background

The deep ultraviolet LED light-emitting element based on III-nitride material has wide application prospect in the fields of sterilization, polymer curing, biochemical detection, non-line-of-sight communication, special illumination and the like. Compared with the traditional ultraviolet light source mercury lamp, the ultraviolet light source mercury lamp has the well-known advantages of environmental protection, small size, portability, low power consumption, low voltage and the like, and has been paid more attention in recent years.

The deep ultraviolet LED light-emitting element comprises a deep ultraviolet LED chip and a packaging structure, wherein the deep ultraviolet LED chip is used for emitting ultraviolet rays, and the packaging structure is used for packaging the deep ultraviolet LED chip. It is well known that ultraviolet rays have a short propagation distance in air and are easily absorbed by other materials. Therefore, the type of the package structure should be reasonably selected to reduce the shielding and absorption of ultraviolet rays by the package structure. In particular, the conventional glue filling packaging mode cannot be adopted, because the glue made of organic materials can strongly absorb ultraviolet light emitted by the deep ultraviolet LED, and the ultraviolet light can damage the molecular structure of the organic glue to cause the packaging structure to fail. The existing deep ultraviolet LED luminous element is characterized in that a deep ultraviolet LED chip is fixed in a bracket bowl cup, an optical glass lens is provided, and the optical glass lens is adhered to the top of a surrounding dam of a bracket by means of an adhesive material to form a closed structure. The containment structure is waterproof, dust-proof and resistant to mechanical damage, but has obvious optical drawbacks. Specifically, the ultraviolet rays emitted from the inside of the deep ultraviolet LED chip will need to pass through the inside of the deep ultraviolet LED chip, the air, the lower surface of the lens, the upper surface of the lens, and the air, compared with the deep ultraviolet LED chip, glue and air mode under the glue filling encapsulation structure, the ultraviolet rays need to pass through more interfaces, and the refractive index difference of materials at two sides of the interfaces is too large, especially the deep ultraviolet LED chip-air interface, and is far larger than the deep ultraviolet LED chip-glue interface, so that most rays are totally reflected back to the inside of the bracket and cannot be emitted.

The patent with publication number CN 110197865A discloses a liquid-packaged deep ultraviolet LED packaging device and a preparation method thereof, wherein a deep ultraviolet LED chip is positioned in a closed space inside a packaging structure, and silicone oil is filled in the closed space to improve the transmittance of ultraviolet rays. However, the technical scheme still has the defects of difficult process control, low yield, oil leakage risk and the like, and is not an optimal packaging material for the deep ultraviolet LED at present based on the physicochemical properties of silicone oil.

In view of this, it is necessary to propose a new solution.

Disclosure of Invention

The invention aims to provide a deep ultraviolet LED light-emitting element and a preparation method thereof, aiming at improving the light-emitting efficiency and reliability of the deep ultraviolet LED light-emitting element.

In order to achieve the above object, the present invention provides the following solutions:

the invention discloses a deep ultraviolet LED luminous element, which comprises:

the bracket is provided with a containing groove;

the deep ultraviolet LED chip is fixed in the accommodating groove, and the light-emitting side of the deep ultraviolet LED chip faces the notch of the accommodating groove;

a first lens covering at least a light emitting side of the deep ultraviolet LED chip, an ultraviolet transmittance of the first lens being not lower than 50%, a refractive index of the first lens being greater than 1 and less than a refractive index of the deep ultraviolet LED chip;

the second lens is fixed on the bracket and covers the notch of the accommodating groove;

the conductive component is arranged on the bracket and comprises a positive conductive piece used for connecting the positive electrode of the power supply and a negative conductive piece used for connecting the negative electrode of the power supply; the positive electrode conductive piece and the negative electrode conductive piece are electrically connected with the deep ultraviolet LED chip so as to supply power for the deep ultraviolet LED chip.

Preferably, the bracket comprises a base plate and a surrounding dam fixed on the base plate, the surrounding dam is enclosed into a ring shape, and the accommodating groove is positioned on the inner side of the surrounding dam.

Preferably, a limiting groove is formed in one side, away from the base plate, of the dam, and the second lens part extends into the limiting groove.

Preferably, the limit groove is a stepped groove, and the limit groove is located at the inner side of one surface of the dam, which faces away from the base plate.

Preferably, the material of the first lens is a fluorine-containing polymer.

Preferably, the positive electrode conductive member and the negative electrode conductive member both pass through the bracket.

Preferably, the LED further comprises a zener diode, wherein the positive electrode conductive piece and the negative electrode conductive piece are electrically connected with the zener diode, so that the zener diode is connected with the deep ultraviolet LED chip in parallel.

Preferably, a side of the first lens, which is close to the second lens, is a raised curved surface.

The invention also discloses a preparation method of the deep ultraviolet LED luminous element, which comprises the following steps:

step one: fixing a deep ultraviolet LED chip in a containing groove of a bracket, so that the light-emitting side of the deep ultraviolet LED chip faces towards a notch of the containing groove;

step two: forming a first lens covering the light emitting side of the deep ultraviolet LED chip on the deep ultraviolet LED chip, wherein the ultraviolet transmittance of the first lens is not lower than 50 percent, and the refractive index of the first lens is larger than 1 and smaller than that of the deep ultraviolet LED chip;

step three: and fixing the second lens on the bracket, so that the second lens covers the notch of the accommodating groove, and a deep ultraviolet LED light-emitting element is obtained.

step one: forming a first lens covering the light emitting side of the deep ultraviolet LED wafer on the deep ultraviolet LED wafer, wherein the ultraviolet transmittance of the first lens is not lower than 50 percent, and the refractive index of the first lens is more than 1 and less than that of the deep ultraviolet LED chip;

step two: cutting the deep ultraviolet LED wafer to obtain a combination of a deep ultraviolet LED chip and the first lens;

step three: fixing the combination body in a containing groove of a bracket, so that the light-emitting side of the deep ultraviolet LED chip faces the notch of the containing groove;

step four: and fixing the second lens on the bracket, so that the second lens covers the notch of the accommodating groove, and a deep ultraviolet LED light-emitting element is obtained.

Compared with the prior art, the invention has the following technical effects:

the invention provides a deep ultraviolet LED light-emitting element, wherein a first lens is coated on the light-emitting side of a deep ultraviolet LED chip. The refractive index of the first lens is larger than 1 and smaller than that of the deep ultraviolet LED chip, so that the refractive index difference of the two sides of the interface of the deep ultraviolet LED chip and the first lens is smaller than that of the two sides of the interface of the deep ultraviolet LED chip and air, total reflection of ultraviolet is reduced, and ultraviolet extraction efficiency is improved. The ultraviolet transmittance of the first lens is not lower than 50%, so that the absorption of ultraviolet rays can be reduced, and the ultraviolet ray extraction efficiency can be improved. In addition, the support and the second lens can protect the deep ultraviolet LED chip in the accommodating groove, so that the service life of the deep ultraviolet LED chip is prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1a, 1b and 1c are three package structures commonly used in the prior art, respectively;

fig. 2 is a schematic structural diagram of a deep ultraviolet LED light emitting device according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a deep ultraviolet LED light emitting device according to a second embodiment of the present invention;

fig. 4 is a schematic structural diagram of a deep ultraviolet LED light emitting device according to a third embodiment of the present invention;

fig. 5 is a schematic structural diagram of a deep ultraviolet LED light emitting device according to a fourth embodiment of the present invention;

FIG. 6 is a schematic diagram of a conventional wafer in a second method of manufacturing the present invention;

FIG. 7 is a schematic diagram of a second method for fabricating a first lens on a light emitting surface of a conventional wafer;

FIG. 8 is a schematic diagram of a process for forming a first lens;

fig. 9 is a physical diagram of the first lens.

Reference numerals illustrate: 100-a substrate; 101-a surrounding dam; 102 a-a first pad; 102 b-a second pad; 103 a-third pads; 103 b-fourth pads; 104-deep ultraviolet LED chips; 105-a first lens; 106-a second lens; 107-zener diodes; 200-conventional wafer.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

Fig. 1a, 1b and 1c show three common packaging structures in the prior art. In fig. 1a, a lens made of quartz glass is used to form a package element with a support. Whereas figure 1b illustrates filling the cavity of the dam 101 with glue, typically with silicone or epoxy. Fig. 1c shows the direct plastic molding of glue by the die-top process. In addition to the conventional structure of fig. 1a, the structures of fig. 1b and 1c are difficult to apply to the package structure of the deep ultraviolet LED light emitting element. This is because conventional silicone or epoxy adhesives have poor ultraviolet resistance or poor ultraviolet transmittance, and thus cannot be used as an ideal packaging material for deep ultraviolet LED light emitting elements. In the prior art, the types of the high polymer materials capable of meeting the two conditions of ultraviolet tolerance and ultraviolet band permeability are very limited, and in practical application, the high polymer materials have various defects such as high price, difficult processing, poor high temperature resistance, insufficient hardness, easy falling off, poor suitability and the like. Therefore, it is difficult to use these limited types of high molecular polymer materials as a host material for deep ultraviolet packaging structures.

Referring to fig. 2 to 9, the present invention provides a deep ultraviolet LED light emitting element, which includes a bracket, a deep ultraviolet LED chip 104, a first lens 105, a second lens 106, and a conductive component.

The bracket is provided with a containing groove, and the deep ultraviolet LED chip 104 is fixed in the containing groove, so that the deep ultraviolet LED chip 104 is protected through the containing groove, and the functions of dust prevention and collision prevention are achieved. The light emitting side of the deep ultraviolet LED chip 104 faces the notch of the accommodating groove, so that ultraviolet rays emitted by the deep ultraviolet LED chip 104 can be emitted outwards through the notch of the accommodating groove. The deep ultraviolet LED chip 104 can emit ultraviolet rays.

The first lens 105 covers at least the light emitting side (i.e., light emitting surface) of the deep ultraviolet LED chip 104, the first lens 105 has an ultraviolet transmittance of not less than 50%, and the refractive index of the first lens 105 is greater than 1 and less than the refractive index of the deep ultraviolet LED chip 104 (the refractive index of the deep ultraviolet LED chip 104 is about 1.7). Specifically, the first lens 105 may cover only the light emitting side of the deep ultraviolet LED chip 104, or may cover both the light emitting side of the deep ultraviolet LED chip 104 and the surrounding sidewalls thereof. The size of the first lens 105 (or referred to as a microlens) should be as small as possible to reduce material loss.

The second lens 106 is fixed on the support, and the notch of holding groove is covered to the second lens 106 to protect the deep ultraviolet LED chip 104 in the holding groove, play dustproof, anticollision effect. When the accommodating groove is completely sealed, the waterproof effect can be achieved. The material of the second lens 106 may be one or more of silicon oxide, aluminum oxide, titanium oxide, magnesium fluoride, calcium fluoride, lead sulfide, quartz. The surface of the second lens 106 near the side of the first lens 105 may be planar, spherical, or any other shape. The surface of the second lens 106 facing away from the first lens 105 may be planar, spherical or any other shape. The surface of the second lens 106 may be smooth, an array structure, or a roughened structure.

The conductive component is arranged on the bracket and comprises a positive conductive piece used for connecting the positive electrode of the power supply and a negative conductive piece used for connecting the negative electrode of the power supply. The positive conductive member and the negative conductive member are electrically connected with the deep ultraviolet LED chip 104 to supply power to the deep ultraviolet LED chip 104. When the power supply is positioned in the accommodating groove, the positive electrode conductive piece and the negative electrode conductive piece can be only arranged in the accommodating groove and do not need to pass through the bracket. When the power source is located outside the accommodating groove, the positive electrode conductive member and the negative electrode conductive member need to pass through the bracket to be connected with the power source outside the accommodating groove and the deep ultraviolet LED chip 104 inside the accommodating groove respectively.

The invention provides a deep ultraviolet LED light-emitting element, wherein a light-emitting side of a deep ultraviolet LED chip 104 is coated with a first lens 105. The refractive index of the first lens 105 is greater than 1 and smaller than that of the deep ultraviolet LED chip 104, so that the refractive index difference at two sides of the interface between the deep ultraviolet LED chip 104 and the first lens 105 is smaller than that at two sides of the interface between the deep ultraviolet LED chip 104 and air, thereby reducing total reflection of ultraviolet rays and improving ultraviolet ray extraction efficiency. The ultraviolet ray transmittance of the first lens 105 is not lower than 50%, and thus the absorption of ultraviolet rays can be reduced, and the ultraviolet ray extraction efficiency can be improved. In addition, the bracket and the second lens 106 can protect the deep ultraviolet LED chip 104 in the accommodating groove, so as to prolong the service life of the deep ultraviolet LED chip 104.

As a possible example, the stand includes a base plate 100 and a case dam 101 fixed to the base plate 100, the case dam 101 is enclosed in a ring shape, and the receiving groove is located inside the case dam 101. The weirs 101 may be annular. Depending on the actual needs, the dam 101 may have other shapes such as a square ring shape.

The materials of the base plate 100 and the weirs 101 can be flexibly selected. The substrate 100 is typically a non-metallic material, such as ceramic. The dam 101 may be made of the same ceramic material as the bracket, and the two may be fixedly connected by co-temperature sintering to obtain the bracket. The dam 101 may be made of a metal material, and the surface thereof may be subjected to a process such as plating or electroless plating. The weirs 101 may be made of a non-metallic material other than ceramic. The dam 101 and the base plate 100 may be bonded to each other by means of an adhesive material to obtain a bracket.

As a possible example, the side of the dam 101 facing away from the base plate 100 is provided with a limit groove, and the second lens 106 partially extends into the limit groove to provide a mounting position of the second lens 106, so that the second lens is mounted more firmly.

As a possible example, the limit groove is a stepped groove, and the limit groove is located on the inner side of the dam 101 facing away from the base plate 100. One side of the second lens 106, which is close to the first lens 105, can be adhered to the groove body of the stepped groove, and the second lens 106 can be in contact with the groove wall of the stepped groove to limit the movement of the second lens 106 along the direction parallel to the substrate 100.

As a possible example, the material of the first lens 105 is a fluoropolymer (english name: perfluor (1-butenyl vinyl ether) polymer, and the refractive index is about 1.3). The ultraviolet ray has a transmittance of 90% or more in the fluoropolymer material, and is hardly affected by ultraviolet rays (does not crack, decompose, turn yellow under ultraviolet irradiation), so that the absorption of ultraviolet rays can be reduced. The material of the first lens 105 may be other organic or inorganic glue that satisfies the refractive index and ultraviolet transmittance requirements of the present invention.

As one possible example, both the positive and negative conductive members pass through the support. Specifically, the portion of the positive electrode conductive member located in the accommodating groove is a first bonding pad 102a, and the portion of the positive electrode conductive member located outside the accommodating groove is a third bonding pad 103a. The portion of the negative electrode conductive member located in the accommodating groove is a second bonding pad 102b, and the portion of the negative electrode conductive member located outside the accommodating groove is a fourth bonding pad 103b.

The materials of the positive electrode conductive member and the negative electrode conductive member can be one or more selected from aluminum, silver, gold, copper, tin, lead and platinum.

As one possible example, the deep ultraviolet LED chip 104 may be a flip chip, a vertical structure chip, or other type of chip based on a sapphire substrate. When a flip chip is selected, the two metal electrodes of the flip chip are soldered to the first and second pads 102a, 102b, respectively, by means of metal solders (e.g., solder paste, silver paste, gold-tin alloy, etc.).

As a possible example, the deep ultraviolet LED light emitting element further includes a zener diode 107, and the positive conductive member and the negative conductive member are electrically connected to the zener diode 107, so that the zener diode 107 is connected in parallel with the deep ultraviolet LED chip 104.

As one possible example, the side of the first lens 105 close to the second lens 106 is a curved surface bulging toward the second lens 106.

As one possible example, the first lens 105 is coaxial with the second lens 106. When the side of the first lens 105 close to the second lens 106 is a convex curved surface, and the side of the second lens 106 away from the first lens 105 is a convex curved surface, a better ultraviolet radiation effect can be achieved.

Embodiment 1,

Referring to fig. 2, the present embodiment provides a deep ultraviolet LED light emitting element, which includes a bracket, a deep ultraviolet LED chip 104, a first lens 105, a second lens 106, and a conductive component.

The bracket is provided with a containing groove, and the deep ultraviolet LED chip 104 is fixed in the containing groove, so that the deep ultraviolet LED chip 104 is protected through the containing groove, and the functions of dust prevention and collision prevention are achieved. The light emitting side of the deep ultraviolet LED chip 104 faces the notch of the accommodating groove, so that ultraviolet rays emitted by the deep ultraviolet LED chip 104 can be emitted outwards through the notch of the accommodating groove. The deep ultraviolet LED chip 104 can emit ultraviolet rays. The first lens 105 has an ultraviolet transmittance of not less than 50%, and the refractive index of the first lens 105 is greater than 1 and less than that of the deep ultraviolet LED chip 104. The second lens 106 is fixed on the support, and the notch of holding groove is covered to the second lens 106 to protect the deep ultraviolet LED chip 104 in the holding groove, play dustproof, anticollision effect. The conductive component is arranged on the bracket and comprises a positive conductive piece used for connecting the positive electrode of the power supply and a negative conductive piece used for connecting the negative electrode of the power supply. The positive conductive member and the negative conductive member are electrically connected with the deep ultraviolet LED chip 104 to supply power to the deep ultraviolet LED chip 104.

The deep ultraviolet LED chip 104 is one, the first lens 105 only covers the light emitting side of the deep ultraviolet LED chip 104, and the second lens is hemispherical.

Embodiment II,

Referring to fig. 3, the present embodiment provides a deep ultraviolet LED light emitting device, which is substantially the same as the first embodiment, except that the first lens 105 covers the light emitting side of the deep ultraviolet LED chip 104 and the surrounding sidewalls thereof.

Third embodiment,

Referring to fig. 4, the present embodiment provides a deep ultraviolet LED light emitting element, which is substantially the same as the first embodiment, except that the deep ultraviolet LED chip 104 includes two.

Fourth embodiment,

Referring to fig. 5, the present embodiment provides a deep ultraviolet LED light emitting element, which is substantially the same as the first embodiment, except that a surface of the second lens 106 on a side close to the first lens 105 is a plane, and a surface of the second lens 106 on a side away from the first lens 105 is also a plane.

The invention provides a preparation method (called preparation method I for short) of a deep ultraviolet LED luminous element, which comprises the following steps:

step one: the deep ultraviolet LED chip 104 is fixed in the accommodating groove of the bracket, so that the light emitting side of the deep ultraviolet LED chip 104 faces the notch of the accommodating groove.

Step two: on the deep ultraviolet LED chip 104, a first lens 105 is formed to cover the light emitting side of the deep ultraviolet LED chip 104, the ultraviolet transmittance of the first lens 105 is not lower than 50%, and the refractive index of the first lens 105 is larger than 1 and smaller than that of the deep ultraviolet LED chip 104.

Step three: and fixing the second lens 106 on the bracket, and enabling the second lens 106 to cover the notch of the accommodating groove to obtain the deep ultraviolet LED light-emitting element.

Specifically, the preparation method one can be refined as the following steps:

11 Crystal bonding): a bracket with a box dam 101 structure is provided, a first bonding pad 102a and a second bonding pad 102b on the surface of the bracket are pre-coated with solder, the positive electrode of a deep ultraviolet LED chip 104 is connected to the first bonding pad 102a, the negative electrode of the deep ultraviolet LED chip 104 is connected to the second bonding pad 102b, the positive electrode of a zener diode 107 chip is connected to the first bonding pad 102a, and the negative electrode of the zener diode 107 chip is connected to the second bonding pad 102b.

12 Surface treatment: and (3) placing the product obtained in the step (1) into a cleaning agent for cleaning, and drying after washing with clear water. Or placing the product obtained in the step 1) into a plasma cleaning machine to clean the surface of the bracket, and cleaning.

This step is used to remove residual flux in the solder and impurities on the support, facilitating the attachment of the first lens 105 and the second lens 106.

13 First lens 105 molding: typically, the fluoropolymer is dissolved in a particular solvent and, prior to use, is concentrated to the desired viscosity by appropriate heating. The fluoropolymer may be CYTOP (amorphous fluoropolymer fluororesin) and is commercially available as such, and the purchased product is generally dissolved in a solvent and does not need to be dissolved again (as is the case with the second method of preparation).

In a simple preparation method, fluoropolymer droplets are directly instilled on the light emitting side of the ultraviolet LED chip. Depending on the size of the deep ultraviolet LED chip 104, care should be taken to control the amount of droplets instilled so that after slow flow, the entire chip light emitting surface is covered. Further, the mixture is baked again, and the solvent in the fluoropolymer is partially evaporated and cured slowly. As shown in fig. 8, the fluoropolymer will cover the light emitting surface of the chip in a thin film shape with the central portion raised by the surface tension of the fluoropolymer solution itself. And then dripping liquid drops on the first layer film in the same way, and properly baking to form a second layer film. The bottom of the second layer of film is integrated with the first layer of film, and the middle of the second layer of film is further raised to increase the spherical shape. And so on, step up to the proper height until the first lens 105 is obtained.

In another method, the fluoropolymer droplets are quantitatively placed in a mold, then the mold is tightly combined with the deep ultraviolet LED chip 104 welded on the bracket, and the fluoropolymer is molded and coated on the periphery of the deep ultraviolet LED chip 104 in a hot pressing mode. By changing the mold design, the shape and size of the first lens 105 can be adjusted.

Finally, the two methods result in a first lens 105 covering at least the light emitting side of the deep ultraviolet LED chip 104.

14 Assembled second lens 106): the stepped groove on the top surface of the dam 101 is pre-coated with an adhesive material, such as conventional organic glue, to bring the second lens 106 into contact with the bottom of the stepped groove. Depending on the kind of the adhesive material, conditions such as high-temperature baking, standing, welding, etc. are provided to cure the adhesive material.

15 Cutting the stent: and cutting the bracket to obtain the deep ultraviolet LED luminous element.

The thinned preparation method I can be used for preparing the deep ultraviolet LED luminous elements corresponding to the first to fourth embodiments.

The invention also provides a preparation method (called a preparation method II for short) of the deep ultraviolet LED luminous element, which comprises the following steps:

step one: on the deep ultraviolet LED wafer, a first lens 105 is formed to cover the light emitting side of the deep ultraviolet LED wafer, the ultraviolet transmittance of the first lens 105 is not lower than 50%, and the refractive index of the first lens 105 is greater than 1 and smaller than the refractive index of the deep ultraviolet LED chip 104.

Step two: the deep ultraviolet LED wafer is diced to obtain a combination of the deep ultraviolet LED chips and the first lens 105 (the deep ultraviolet LED wafer is diced into a plurality of deep ultraviolet LED chips 104).

Step three: the assembly is fixed in the accommodating groove of the bracket, so that the light emitting side of the deep ultraviolet LED chip 104 faces the notch of the accommodating groove.

Step four: and fixing the second lens 106 on the bracket, and enabling the second lens 106 to cover the notch of the accommodating groove to obtain the deep ultraviolet LED light-emitting element.

Specifically, the second preparation method can be refined as the following steps:

21 Preparation: a deep ultraviolet LED wafer (or referred to as conventional wafer 200) is provided, thinned and polished to a desired thickness in accordance with conventional procedures, and cleaned.

22 First lens 105 molding: typically, the fluoropolymer is dissolved in a particular solvent and, prior to use, is concentrated to the desired viscosity by appropriate heating.

In one of the two methods provided in the above step 13), a plurality of first lenses 105 are obtained, which are discretely distributed on the deep ultraviolet LED wafer.

23 Dicing the wafer: the deep ultraviolet LED wafer is diced according to conventional methods to obtain a combination of deep ultraviolet LED chips and the first lens 105.

24 Test): test sorting the product obtained in step 23).

25 Welding: a bracket with a box dam 101 structure is provided, a first bonding pad 102a and a second bonding pad 102b on the surface of the bracket are pre-coated with solder, the positive electrode of a deep ultraviolet LED chip 104 is connected to the first bonding pad 102a, the negative electrode of the deep ultraviolet LED chip 104 is connected to the second bonding pad 102b, the positive electrode of a zener diode 107 chip is connected to the first bonding pad 102a, and the negative electrode of the zener diode 107 chip is connected to the second bonding pad 102b.

26 Surface treatment: and (3) placing the product obtained in the step 25) into a cleaning agent for cleaning, and drying after washing with clear water. Or placing the product obtained in the step 25) into a plasma cleaning machine to clean the surface of the bracket.

This step serves to remove residual flux in the solder and impurities on the support, facilitating attachment of the second lens 106.

27 Assembled second lens 106): the stepped groove on the top surface of the dam 101 is pre-coated with an adhesive material, such as conventional organic glue, to bring the second lens 106 into contact with the bottom of the stepped groove. Depending on the kind of the adhesive material, conditions such as high-temperature baking, standing, welding, etc. are provided to cure the adhesive material.

28 Cutting again: and cutting the bracket to obtain the deep ultraviolet LED luminous element.

The principles and embodiments of the present invention have been described in this specification with reference to specific examples, the description of which is only for the purpose of aiding in understanding the method of the present invention and its core ideas; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.

Claims

1. A deep ultraviolet LED lighting element, comprising:

the bracket is provided with a containing groove;

2. The deep ultraviolet LED lighting element according to claim 1, wherein the bracket comprises a base plate and a dam fixed on the base plate, the dam is enclosed in a ring shape, and the accommodating groove is located inside the dam.

3. The deep ultraviolet LED lighting element according to claim 2, wherein a limiting groove is formed in a side of the dam facing away from the substrate, and the second lens portion extends into the limiting groove.

4. The deep ultraviolet LED lighting element according to claim 3, wherein the limit groove is a stepped groove, and the limit groove is located at an inner side of one surface of the dam facing away from the substrate.

5. The deep ultraviolet LED lighting element according to claim 1, wherein the first lens is made of a fluoropolymer.

6. The deep ultraviolet LED lighting element according to claim 1, wherein the positive electrode conductive member and the negative electrode conductive member each pass through the bracket.

7. The deep ultraviolet LED lighting element according to claim 1, further comprising a zener diode, wherein the positive conductive member and the negative conductive member are each electrically connected to the zener diode such that the zener diode is in parallel with the deep ultraviolet LED chip.

8. The deep ultraviolet LED lighting element according to claim 1, wherein a side of the first lens adjacent to the second lens is a curved surface that is convex.

9. The preparation method of the deep ultraviolet LED light-emitting element is characterized by comprising the following steps of:

10. The preparation method of the deep ultraviolet LED light-emitting element is characterized by comprising the following steps of: