A deep ultraviolet LED packaging structure and packaging method thereof

Abstract

The present invention belongs to the field of LED packaging technology and relates to a deep ultraviolet LED packaging structure and a packaging method thereof, comprising a substrate, an LED unit, a metal frame, a retaining wall structure, a packaging adhesive layer and a translucent cover plate, wherein the metal frame comprises a frame bottom and a frame body, the frame bottom is arranged on the front side of the substrate and is located at the periphery of a first solder pad group, and the frame body is arranged on the frame bottom; a step structure is formed between the outer wall of the frame body and the frame bottom; the wall portion of the retaining wall structure is arranged on the frame bottom, and a groove for filling the packaging adhesive is formed between the wall portion and the metal frame; the translucent cover plate is placed on the top end of the frame body of the metal frame, and the part of the translucent cover plate extending out of the top end of the frame body is bonded and packaged together with the metal frame and the wall portion through the packaging adhesive layer; the deep ultraviolet LED packaging structure has low requirements for controlling the amount of glue dispensed, good airtightness, and high stability, which is conducive to improving the packaging efficiency of the product and reducing the packaging cost.

Description

Technical Field

[0001] The present invention relates to the technical field of LED packaging, and in particular to a deep ultraviolet LED packaging structure and a packaging method thereof. Background Art

[0002] Deep UV LEDs are LED products that use deep ultraviolet light (UV-C light for short) to sterilize. However, deep UV light places special demands on packaging materials. For example, organic materials such as silicone easily turn yellow and age when exposed to deep UV light. Current UV products primarily use a packaging technology that coats the upper edge of a cup with a ceramic base with glue, then places a flat quartz glass or quartz lens. While this packaging technology can to some extent reduce the aging of organic materials and failures caused by moisture and heat stress, ensuring product stability and reliability, the inventors discovered in practice that this packaging technology has at least the following drawbacks:

[0003] (1) When applying glue on the upper edge of the cup body of the ceramic substrate with a cup, the glue dispensing head needs to run along the upper edge of the cup body at a uniform speed for one circle. The glue dispensing efficiency is low, and the glue amount is difficult to control. It is often easy to dispense too much or too little glue. Among them, when the glue dispensing amount is large, it is easy for the glue to overflow and flow into the cup. Under the long-term irradiation of the deep ultraviolet light emitted by the chip, it will cause the glue layer to crack. In addition, the deep ultraviolet light energy radiated to the colloid is easy to cause light decay, which weakens the sterilization effect.

[0004] (2) During packaging, the quartz glass or quartz lens cover is prone to deviation or removal from the cup body, and thus needs to be manually straightened, resulting in a long packaging time and low packaging efficiency, as well as a waste of manpower and material resources and a high packaging cost. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a deep ultraviolet LED packaging structure, which is used to solve the technical problems of low dispensing efficiency in the existing deep ultraviolet LED product packaging technology, easy light decay due to difficulty in controlling the dispensing amount, and low overall packaging efficiency and high packaging cost due to difficulty in aligning the cover plate.

[0006] In order to solve the above technical problems, the following technical solutions are adopted:

[0007] The deep ultraviolet LED packaging structure includes a substrate, an LED unit, a metal frame, a retaining wall structure, a packaging adhesive layer and a light-transmitting cover plate; the metal frame is enclosed on the front of the substrate to form a receiving cavity;

[0008] A first pad group is provided on the front surface of the substrate, and the first pad group is located in the accommodating cavity and is insulated from the metal frame;

[0009] The LED unit is in the accommodating cavity and is arranged on the first solder pad group;

[0010] The metal frame includes a frame bottom and a frame body, wherein the frame bottom is arranged on the front surface of the substrate and is located outside the first pad group, and the frame body is arranged on the frame bottom; a step structure is formed between the outer side wall of the frame body and the frame bottom;

[0011] The retaining wall structure is located at the periphery of the frame body, and the retaining wall structure includes a surrounding wall portion, the surrounding wall portion is arranged on the frame bottom, and a groove for filling the encapsulation colloid is formed between the surrounding wall portion and the metal frame;

[0012] The encapsulation adhesive layer is formed by the encapsulation adhesive filling the groove;

[0013] The transparent cover is placed on the top of the metal frame. The portion of the transparent cover extending from the top of the frame is bonded to the metal frame and the surrounding wall through the packaging adhesive layer to seal the accommodating cavity.

[0014] In some embodiments, the top surface of the surrounding wall portion of the retaining wall structure is flush with the top surface of the frame; and the outer wall of the light-transmitting cover plate is flush with the outer wall of the surrounding wall portion.

[0015] Furthermore, in some embodiments, the wall portion of the retaining wall structure is formed by solidifying an opaque colloid material.

[0016] Furthermore, or in other embodiments, the surrounding wall portion of the retaining wall structure and the light-transmitting cover plate are integrally formed, and the surrounding wall portion and the light-transmitting cover plate are made of the same light-transmitting material.

[0017] Alternatively, in other embodiments, the retaining wall structure further includes a first protective portion, which is disposed on the top of the surrounding wall portion and is located outside the light-transmitting cover plate to cover the light-transmitting cover plate.

[0018] Furthermore, in these embodiments, the surrounding wall portion and the first protective portion of the retaining wall structure are solidified and formed separately or integrally, and both the surrounding wall portion and the first protective portion are solidified from an opaque colloid material.

[0019] Furthermore, in some of the above embodiments, a first concave-convex structure is formed on the outer side wall of the frame.

[0020] Furthermore, in some of the above embodiments, a second concave-convex structure is formed on the inner side wall of the surrounding wall portion of the retaining wall structure.

[0021] Furthermore, in some of the above embodiments, the thickness of the frame bottom ranges from 60 μm to 100 μm.

[0022] Furthermore, in some of the above embodiments, a second pad group is provided on the reverse side of the substrate, the second pad group including a middle pad and connecting pads located on opposite sides of the middle pad, and the area of ​​the middle pad is 1.1 to 3 times the area of ​​the connecting pad.

[0023] In order to solve the above technical problems, an embodiment of the present invention further provides a deep ultraviolet LED packaging method, which adopts the following technical solution: the deep ultraviolet LED packaging method is used to package the above deep ultraviolet LED packaging structure, comprising the following steps:

[0024] providing a metal frame on the front surface of the substrate;

[0025] A first colloid is applied to the bottom of the metal frame at the periphery of the frame, and the first colloid forms the wall portion of the retaining wall structure after solidification;

[0026] The groove formed between the wall portion and the frame is filled with encapsulating colloid;

[0027] Placing a translucent cover plate on the top of the frame body, and making a portion of the translucent cover plate extend from the top of the frame body to contact the packaging colloid and cover the accommodating cavity where the LED unit is arranged;

[0028] The encapsulating colloid is cured.

[0029] In some embodiments, the deep ultraviolet LED packaging method further includes the following steps:

[0030] When the outer wall of the light-transmitting cover is located between the outer wall of the surrounding wall and the outer wall of the frame, a second colloid is applied to the top of the surrounding wall to protect the light-transmitting cover. After the second colloid is cured, the first protective portion of the surrounding wall is formed.

[0031] In some embodiments, the viscosity of the first colloid used in the surrounding wall portion of the retaining wall structure is 3 to 10 times the viscosity of the encapsulating colloid.

[0032] Compared with the prior art, the deep ultraviolet LED packaging structure and packaging method provided by the embodiments of the present invention have the following advantages:

[0033] The deep ultraviolet LED packaging structure is enclosed by a metal frame and a wall portion of a retaining wall structure to form a groove for filling the packaging colloid, and a transparent cover plate is placed on the top of the frame. There is no need to coat the contact surface of the frame and the transparent cover plate with colloid, but a packaging glue layer is directly formed outside the metal frame, which is beneficial to improving the packaging efficiency and can reduce the process difficulty of controlling the dispensing amount to a certain extent. Specifically, on the one hand, when the dispensing amount of packaging colloid is large, it can be ensured that the packaging colloid will not flow into the accommodating cavity where the LED unit is encapsulated, thereby avoiding light decay.

[0034] On the other hand, because the light-transmitting cover is mainly supported by the frame of the metal frame, the light-transmitting cover only needs to extend a portion from the top of the frame toward the direction of the retaining wall structure. In addition, because the surrounding wall part has been aligned in advance, it is beneficial to effectively improve the alignment problem when the light-transmitting cover is closed, which is beneficial to improve the packaging efficiency of the product and reduce the packaging cost.

[0035] In general, the deep ultraviolet LED packaging structure has good structural stability, high reliability, and low requirements for control of the dispensing amount; the corresponding packaging method is simple and reliable, with high packaging efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] To more clearly illustrate the solutions of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0037] Figure 1 is a cross-sectional view of a deep ultraviolet LED packaging structure in embodiment 1 of the present invention;

[0038] Figure 2 yes Figure 1 A cross-sectional view of the mating between the substrate and metal frame of the mid- to deep-ultraviolet LED packaging structure;

[0039] Figure 3 is a cross-sectional view of a deep ultraviolet LED packaging structure in embodiment 2 of the present invention;

[0040] Figure 4 is a cross-sectional view of a deep ultraviolet LED packaging structure in embodiment 3 of the present invention;

[0041] Figure 5 is a cross-sectional view of another deep ultraviolet LED packaging structure in embodiment 3 of the present invention;

[0042] Figure 6 is a cross-sectional view of another deep ultraviolet LED packaging structure in the third embodiment of the present invention;

[0043] Figure 7 This is a flow chart of a packaging method for a deep ultraviolet LED packaging structure in Example 1 of the present invention;

[0044] Figure 8 This is a flow chart of the packaging method of the deep ultraviolet LED packaging structure in the third embodiment of the present invention.

[0045] The reference numerals in the accompanying drawings are as follows:

[0046] 10. Deep ultraviolet LED packaging structure;

[0047] 100, substrate; 110, first pad group; 120, second pad group; 121, middle pad; 122, connecting pad;

[0048] 200, LED unit;

[0049] 300, metal frame; 310, frame bottom; 320, frame body; 321, first frame portion; 322, second frame portion; 323, first concave-convex structure; 330, step structure;

[0050] 400, retaining wall structure; 410, surrounding wall portion; 411, second concave-convex structure; 420, first protective portion; 430, second protective portion;

[0051] 500, encapsulation adhesive layer; 600, light-transmitting cover plate; 700, accommodating cavity; 800, groove. DETAILED DESCRIPTION

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the present invention pertains; the terms used in the specification herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention; for example, the directions or positions indicated by the terms "length", "width", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are for ease of description only and should not be construed as limiting the present technical solution.

[0053] The terms "including," "having," and any variations thereof in the present specification, claims, and accompanying drawings are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the present specification, claims, and accompanying drawings are used to distinguish between different items, not to describe a particular order. "Multiple" means two or more, unless otherwise expressly specified.

[0054] In the specification and claims of the present invention and the above-mentioned description of the drawings, when an element is referred to as being “fixed to,” “mounted on,” “disposed on,” or “connected to” another element, it may be directly or indirectly located on the other element. For example, when an element is referred to as being “connected to” another element, it may be directly or indirectly connected to the other element.

[0055] Furthermore, references herein to an "embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0056] It should be noted that the deep ultraviolet LED package structure 10 can be an LED sterilization device or an LED light source device, and of course, it can also have other uses in other appropriate fields. It should also be noted that the "outer wall" below generally refers to the side wall away from the LED unit 200; correspondingly, the "inner wall" below generally refers to the side wall close to the LED unit 200. The LED unit 200 is generally a deep ultraviolet chip, but in practice, it can also be other suitable deep ultraviolet LED units.

[0057] Embodiment 1 of the deep ultraviolet LED packaging structure 10 of the present invention

[0058] The embodiment of the present invention provides a deep ultraviolet LED packaging structure 10, such as Figure 1 As shown, the deep ultraviolet LED packaging structure 10 includes a substrate 100, an LED unit 200, a metal frame 300, a retaining wall structure 400, a packaging adhesive layer 500 and a transparent cover 600, wherein the metal frame 300 is arranged on the front of the substrate 100 and encloses a receiving cavity 700. Figure 1 and Figure 2 As shown, a first solder pad group 110 is provided on the front of the substrate 100 , wherein the first solder pad group 110 is located in the receiving cavity 700 and is insulated from the metal frame 300 . The LED unit 200 is located in the receiving cavity 700 and is provided on the first solder pad group 110 .

[0059] Furthermore, to achieve electrical connection of the deep ultraviolet LED package structure 10 and enable the normal operation of the LED unit 200, a second pad group 120 is typically provided on the reverse side of the substrate 100. The second pad group 120 includes a middle pad 121 and connecting pads 122, with connecting pads 122 provided on opposite sides of the middle pad 121. Specifically, in this embodiment, the middle pad 121 is primarily used to dissipate heat generated during chip operation; the connecting pads 122 are electrically connected to the first pad group 110 and are primarily used to electrically connect the chip to external circuits.

[0060] like Figure 1 and Figure 2As shown, the metal frame 300 includes a frame bottom 310 and a frame body 320, wherein the frame bottom 310 is arranged on the front surface of the substrate 100 and is located outside the first pad group 110, and the frame body 320 is arranged on the top surface of the frame bottom 310, and a step structure 330 is formed between the outer side wall of the frame body 320 and the frame bottom 310, and the inner side wall of the frame body 320 is flush with the inner side wall of the frame bottom 310. It should be noted that in this embodiment, the bottom area of ​​the frame body 320 is smaller than the top area of ​​the frame bottom 310, and the height of the frame body 320 is greater than the thickness of the frame bottom 310. The frame bottom 310 and the frame body 320 are both made of metal material, and the two can be integrally formed or separately provided.

[0061] In addition, if Figure 2 As shown, to ensure thermal balance between the front and back sides of the substrate and prevent deformation, while also leaving sufficient space for the encapsulation adhesive layer to ensure effective encapsulation bonding, the bottom width b2 of the frame is 0.3 to 0.7 times the width b1 of the frame bottom, with b1-b2 ≥ 100 μm. The thickness of the frame bottom 310 ranges from 60 μm to 100 μm. Specifically, in this embodiment, the area of ​​the intermediate pad 121 is 1.1 to 3 times the area of ​​the connecting pad 122.

[0062] In this embodiment, if Figure 1 As shown, the retaining wall structure 400 is located outside the frame 320. The retaining wall structure 400 includes a wall portion 410. A groove 800 is formed between the wall portion 410 and the metal frame 300. This groove 800 is used to fill the encapsulating colloid. Once the encapsulating colloid fills the groove 800 and is formed (e.g., cured), it forms the encapsulating adhesive layer 500. It is understood that a gap is provided between the wall portion 410 of the retaining wall structure 400 and the frame 320 of the metal frame 300. Specifically, the wall portion 410, the frame 320, and the frame bottom 310 together form the groove 800.

[0063] In this embodiment, if Figure 1 As shown, to facilitate the formation of the groove 800 and to ensure that the retaining wall structure 400 is not cut during subsequent cutting and separation into individual devices, the surrounding wall portion 410 is provided on the frame bottom 310, and the outer sidewall of the retaining wall structure 400 is flush with the outer sidewall of the frame bottom 310. It can be understood that the provision of the frame bottom 310 and the provision of the frame body 320 on the frame bottom 310 can facilitate the positioning of the starting point of the surrounding wall portion 410 by the dispensing head when the retaining wall structure 400 is formed during the packaging process, and facilitate the identification and positioning of the dispensing head.

[0064] In this embodiment, if Figure 1As shown, the transparent cover plate 600 is placed on the top of the frame body 320 of the metal frame 300, and the part of the transparent cover plate 600 extending from the top of the frame body 320 is bonded and packaged together with the metal frame 300 and the surrounding wall part 410 through the packaging glue layer 500 to seal the accommodating cavity 700.

[0065] For the convenience of explanation, Figure 2 As shown, the first pad group 110 and the metal frame 300 can be collectively referred to as a first metal layer (not shown) provided on the front side of the substrate 100, and correspondingly, the metal layer formed by the second pad group 120 is referred to as a second metal layer (not shown) provided on the back side of the substrate 100. It can be understood that by providing a metal stepped metal frame 300 on the front side of the substrate 100 (such as the metal frame 300 is formed with a first concave-convex structure 323 and a step structure 330), the volume of the first metal layer on the front side of the substrate 100 can be reduced, which is beneficial to reduce the heat absorption of the first metal layer during the heating process of package curing, thereby achieving a thermal balance between the front and back sides of the substrate 100, thereby ensuring that the substrate 100 will not be deformed due to uneven heating on the front and back sides. In addition, providing the frame bottom 310 of the metal frame 300 on the front side of the substrate 100 can also increase the contact area between the first metal layer and the front side of the substrate 100 to a certain extent, which is beneficial to improving the heat dissipation performance of the first metal layer.

[0066] It should be noted that in this embodiment, the top of the frame 320 does not need to be coated with glue. To ensure that the transparent cover 600 can be placed flat, the top surface of the frame 320 can be slightly higher than or equal to the top surface of the wall portion 410, wherein the height difference between the two is within 100 μm. The transparent cover 600 is mainly supported by the frame 320 of the metal frame 300. The transparent cover 600 is made of a material with high deep ultraviolet light transmittance, such as glass, quartz glass, etc.

[0067] In summary, compared with the existing technology, the deep ultraviolet LED packaging structure 10 has at least the following beneficial effects: the deep ultraviolet LED packaging structure 10 is enclosed by the metal frame 300 and the wall portion 410 of the retaining wall structure 400 to form a groove 800 for filling the packaging colloid, and the transparent cover 600 is placed on the top of the frame 320. There is no need to coat the contact surface of the frame 320 and the transparent cover 600 with colloid, but a packaging glue layer 500 is directly formed on the outside of the metal frame 300, which is beneficial to improving the packaging efficiency and can reduce the process difficulty of controlling the amount of glue dispensing to a certain extent. Specifically, on the one hand, when the amount of packaging glue dispensing is large, it can be ensured that the packaging glue will not flow into the accommodating cavity 700 encapsulating the LED unit 200, thereby avoiding light decay.

[0068] On the other hand, because the transparent cover plate 600 is primarily supported by the frame body 320 of the metal frame 300, the transparent cover plate 600 only needs to extend partially from the top of the frame body 320 toward the retaining wall structure 400. Furthermore, because the surrounding wall portion 410 has been pre-aligned, this effectively improves alignment issues when the transparent cover plate 600 is closed, thereby improving product packaging efficiency and reducing packaging costs. In particular, when the outer wall of the transparent cover plate 600 is located on the inner side of the surrounding wall portion 410, the surrounding wall portion 410 acts as a limiter for the transparent cover plate 600, further improving the alignment accuracy of the transparent cover plate 600.

[0069] In general, the deep ultraviolet LED packaging structure 10 has good structural stability, high reliability, high packaging efficiency, and low requirements for controlling the amount of glue dispensed.

[0070] In order to make those skilled in the art better understand the present invention, Figure 1 and Figure 2 , clearly and completely describe the technical solutions in the embodiments of the present invention.

[0071] Furthermore, in some specific implementations of this embodiment, such as Figure 1 As shown, to ensure that the light-transmitting cover plate 600 can be placed flat, the top surface of the wall portion 410 of the retaining wall structure 400 is flush with the top surface of the frame 320. That is, the height of the wall portion 410 and the frame 320 are consistent. Figure 1 As shown, to facilitate forming a single package structure, the outer wall of the light-transmitting cover plate 600 extends beyond the inner wall of the surrounding wall portion 410. Preferably, the outer wall of the light-transmitting cover plate 600 is flush with the outer wall of the surrounding wall portion 410. Of course, in practice, the outer wall of the light-transmitting cover plate 600 can also be located between the outer wall and the inner wall of the surrounding wall portion 410. It can be understood that the light-transmitting cover plate 600 is supported by both the surrounding wall portion 410 and the frame 320, which helps to ensure the stability of the overall structure.

[0072] Specifically in this embodiment, the surrounding wall portion 410 of the retaining wall structure 400 is formed by solidifying an opaque colloid material.

[0073] Furthermore, in some specific implementations of this embodiment, the outer wall of the frame 320 is a vertical surface. In order to improve the adhesion between the packaging glue layer 500 and the metal frame 300 and increase the contact area between the packaging glue layer 500 and the metal frame 300, the outer wall of the frame 320 can be an inclined surface, a curved surface, a stepped surface or other structures. Specifically, Figure 1 As shown, a first concave-convex structure 323 is formed on the outer wall of the frame body 320. The specific shape of the first concave-convex structure 323 can be determined according to actual needs.

[0074] It can be understood that when the amount of encapsulation glue dispensed is small, by setting a first concave-convex structure 323 on the outer wall of the metal frame 300, and forming a step structure 330 between the frame body 320 and the frame bottom 310, when the amount of encapsulation glue dispensed is small, it can ensure that the retaining wall structure 400, the metal frame 300, the transparent cover plate 600 and the encapsulation glue layer 500 can be more firmly bonded, thereby ensuring the airtightness of the outer side and top surface of the metal frame 300, without worrying about water vapor entering the accommodating cavity 700.

[0075] Furthermore, in some specific implementations of this embodiment, such as Figure 1 As shown, the first concave-convex structure 323 is a step in a right-angled shape; or, the first concave-convex structure 323 is a step in a rounded shape. Of course, it can actually be other suitable concave-convex structures, such as a portion of the outer wall of the frame 320 being an inclined surface, a curved surface, etc. Specifically in this embodiment, Figure 1 As shown, the first concave-convex structure 323 is specifically a right-angled step. Preferably, the frame body 320 includes a first frame portion 321 and a second frame portion 322. The first frame portion 321 is disposed on the frame bottom 310, and the second frame portion 322 is disposed on the first frame portion 321. The inner sidewall of the first frame portion 321 is flush with the inner sidewall of the second frame portion 322, and a light-transmitting cover plate 600 is placed on the top of the second frame portion 322. Among them, on the side away from the LED unit 200, the connection between the first frame portion 321 and the second frame portion 322 is a right-angled first concave-convex structure 323. Specifically, the top surface of the first frame portion 321 is larger than the bottom surface of the second frame portion 322, and the width of the second frame portion 322 is greater than or equal to 100μm.

[0076] It should be noted that, for example, in other embodiments, Figure 6 As shown, when the first concave-convex structure 323 is a step with rounded corners, the arc radius R is 1 / 10 to 2 / 3 times the width L of the frame bottom. It can be understood that by providing an arc structure, the contact between the encapsulant and the first concave-convex structure 323 can be made into a relatively smooth surface. In this way, compared to when the first concave-convex structure 323 is a step with right angles, the contact between the encapsulant and the first concave-convex structure 323 is closer, which helps to improve the adhesion between the encapsulant and the frame 320.

[0077] Furthermore, in some specific implementations of this embodiment, such as Figure 1As shown, to strengthen the adhesion between the encapsulating adhesive layer 500 and the surrounding wall portion 410, thereby improving the airtightness of the encapsulating structure, a second concave-convex structure 411 is formed on the inner sidewall of the surrounding wall portion 410 of the retaining wall structure 400. It should be noted that, specifically in this embodiment, the second concave-convex structure 411 is located on top of the first concave-convex structure 323 and is arranged opposite the first concave-convex structure 323. That is, the second concave-convex structure 411 and the first concave-convex structure 323 form a cross structure. In this way, by staggering and cross-arranging the second concave-convex structure 411 and the first concave-convex structure 323, the adhesion between the encapsulating adhesive and the frame 320 and the surrounding wall portion 410 is further improved.

[0078] The embodiment of the present invention further provides a deep ultraviolet LED packaging method, wherein the deep ultraviolet LED packaging method is used to package the deep ultraviolet LED packaging structure 10 in this embodiment, such as Figure 7 As shown, the deep ultraviolet LED packaging method includes the following steps:

[0079] S100: A metal frame 300 is provided on the front surface of the substrate 100. Specifically in this embodiment, the outer wall of the metal frame 300 has a first concave-convex structure 323. In practice, the outer wall of the metal frame 300 may also have other structures such as a vertical surface, an inclined surface, a curved surface, or a stepped surface.

[0080] In step S100, the substrate 100 and metal frame 300 can be directly assembled together to form a whole bracket. Furthermore, the substrate 100 is also provided with a first solder pad group 110 and a second solder pad group 120. It should be noted that after step S100, the LED unit 200 can be flip-chip placed within the metal frame 300 and soldered to the first solder pad group 110 on the front surface of the substrate 100 using methods such as eutectic soldering.

[0081] S200 : applying a first colloid on the frame bottom 310 outside the frame body 320 of the metal frame 300 . After the first colloid is cured, the surrounding wall portion 410 of the retaining wall structure 400 is formed.

[0082] It should be noted that when dispensing glue, the outer wall of the frame bottom 310 can be used as the dispensing starting point of the glue dispensing machine, and the first colloid can be dispensed on the frame bottom 310, wherein, preferably, the viscosity of the first colloid used in the wall portion 410 of the retaining wall structure 400 is 3 to 10 times the viscosity of the encapsulation colloid. Preferably, the viscosity range of the first colloid is 40,000 mPa.s to 70,000 mPa.s. In addition, the first colloid can be cured at room temperature or by heating. The shape of the wall portion 410 formed after curing can be square, circular, or other suitable shapes. Correspondingly, the shape of the frame bottom 310 and the frame body 320 of the metal frame 300 can also be square or circular, or other suitable shapes. Usually, the shape of the frame bottom 310 and the frame body 320 is adapted to the shape of the wall portion 410.

[0083] Specifically, in one embodiment of the present embodiment, the first colloid is cured by heating, wherein the curing temperature range is 60°C to 150°C, and specifically, the temperature range is preferably 60°C to 100°C (i.e., low-temperature curing). It should be noted that since the curing temperature range of 60°C to 100°C is relatively low, a heating table can be provided under the substrate 100 so that the first colloid can be immediately cured under the action of the heating table without having to be placed in an oven for baking, thereby improving the packaging efficiency. In addition, the curing time is generally 15 minutes to 30 minutes, and specifically, the curing time is preferably 5 minutes to 15 minutes.

[0084] S300 : The groove 800 formed between the wall portion 410 and the frame body 320 is filled with encapsulant.

[0085] It should be noted that the encapsulating colloid can be a solid colloid or a liquid colloid. When the encapsulating colloid is in liquid form, it is generally dispensed into the groove 800 by a dispensing device. Specifically, to improve the dispensing efficiency, the dispensing device can be used to dispense glue at individual positions above the groove 800 without the need for circumferential dispensing. Taking the square groove as an example, the dispensing device can directly dispense glue at the four corners of the groove 800. The encapsulating colloid can generally be made of materials such as silicone and silicone resin.

[0086] S400: Place a transparent cover plate 600 on the top of the frame 320, with a portion of the transparent cover plate 600 extending from the top of the frame 320 to contact the encapsulant and cover the receiving cavity 700 containing the LED unit 200. The transparent cover plate 600 can be made of a material with high UVC transmittance, such as glass or quartz glass.

[0087] S500: Curing the encapsulating colloid. After curing, a encapsulating adhesive layer 500 can be formed, through which the wall portion 410 of the retaining wall structure 400, the frame body 320 and the frame bottom 310 of the metal frame 300, and the light-transmitting cover plate 600 can be encapsulated together to form a whole. It should be noted that, in this embodiment, the encapsulating colloid adopts a segmented curing process. The curing temperature of the first curing process is 70°C to 100°C, and the curing time is 1h to 3h. The curing temperature of the second curing process is 130°C to 160°C, and the curing time is 2h to 5h. Of course, in practice, the various parameters during curing can also be adjusted according to actual needs.

[0088] It should be noted that during packaging, a plurality of metal frames 300 are usually provided on a substrate 100 , so a cutting and separation process is required to form a plurality of deep ultraviolet LED package units.

[0089] In general, the deep ultraviolet LED packaging method provided by the embodiments of the present invention is simple and reliable, with high packaging efficiency and low cost.

[0090] Embodiment 2 of the deep ultraviolet LED packaging structure 10 of the present invention

[0091] Please see Figure 3 As shown, the main technical features of this embodiment are substantially the same as those of the above-mentioned embodiment 1, and the main differences therefrom are:

[0092] In some specific implementations of this embodiment, Figure 3 As shown, the wall portion 410 of the retaining wall structure 400 is integrally formed with the light-transmitting cover plate 600, and the wall portion 410 and the light-transmitting cover plate 600 are made of the same light-transmitting material. Preferably, the wall portion 410 and the light-transmitting cover plate 600 are both made of materials such as glass or quartz glass, that is, custom-made specialty glass is required. Specifically, in this embodiment, the wall portion 410 is formed with a second concave-convex structure 411.

[0093] Compared with the packaging method in Example 1, the packaging method in this embodiment is different in that: the packaging colloid is first covered on the first concave-convex structure 323 and the step structure 330 of the metal frame 300, and then the transparent cover plate 600 is covered on the metal frame 300 and supported by the metal frame 300, and then the packaging colloid is cured to form a whole.

[0094] As can be understood from the above, since the transparent cover plate 600 and the surrounding wall portion 410 are integrally formed, the transparent cover plate 600 can be effectively prevented from being tilted or moved out of the surrounding wall portion 410, and the packaging process using this structure is simplified.

[0095] Embodiment 3 of the deep ultraviolet LED packaging structure 10 of the present invention

[0096] Please see Figures 4 to 6 As shown, the main technical features of this embodiment are substantially the same as those of the above-mentioned embodiment 1, and the main differences therefrom are:

[0097] Furthermore, in some specific implementations provided in this embodiment, such as Figures 4 to 6 As shown, when the outer wall of the light-transmitting cover plate 600 is located on the inner side of the outer wall of the retaining wall structure 400, that is, between the outer wall of the surrounding wall portion 410 and the outer wall of the frame body 320 of the metal frame 300, the retaining wall structure 400 also includes a first protective portion 420, wherein the first protective portion 420 is arranged on the top of the surrounding wall portion 410 and is located on the periphery of the light-transmitting cover plate 600 to cover the light-transmitting cover plate 600, so that the outer wall of the light-transmitting cover plate 600 can be effectively protected to prevent the light-transmitting cover plate 600 from being broken.

[0098] Preferably, in some specific implementations provided in this embodiment, the wall portion 410 and the first protection portion 420 of the retaining wall structure 400 are solidified or integrally formed, and both the wall portion 410 and the first protection portion 420 are solidified from an opaque colloid material. Figures 4 to 6 As shown, the retaining wall structure 400 may also include a second protective portion 430, wherein the second protective portion 430 is provided at the end of the first protective portion 420 and is located on the top of the light-transmitting cover plate 600. Obviously, by providing the second protective portion 430, the problem of the light-transmitting cover plate 600 being fragile during packaging can be further avoided, while further improving the airtightness of the packaging structure. It should also be noted that when the retaining wall structure 400 includes the surrounding wall portion 410, the first protective portion 420 and the second protective portion 430, the surrounding wall portion 410 and the first protective portion 420 can be integrally formed, and then the second protective portion 430 can be solidified on the first protective portion 420, or the three can be solidified in sequence. When the retaining wall structure 400 includes the surrounding wall portion 410 and the first protective portion 420, the two can be integrally formed, or solidified in sequence, depending on actual needs.

[0099] It should be noted that if Figure 4 As shown, the wall portion 410 does not use the second concave-convex structure 411, and directly uses a right-angle transition. The first concave-convex structure 323 on the metal frame 300 uses a right-angle step, and the corners are not chamfered. Figure 5 As shown, the wall portion 410 does not use the second concave-convex structure 411, and directly uses rounded corner transition. The first concave-convex structure 323 on the metal frame 300 uses a right-angled step, and the corners are chamfered. Figure 6As shown, the wall portion 410 adopts a second concave-convex structure 411 and directly adopts an arc structure, and the first concave-convex structure 323 on the metal frame 300 adopts a rounded step. Specifically, the arc is directly set on the second frame portion 322 of the frame body 320, while the first frame portion 321 is not changed.

[0100] It can be understood that in each embodiment of the present invention, the first concave-convex structure 323 and the second concave-convex structure 411 can both adopt right-angled steps or rounded steps, and the specific structure adopted can be determined according to actual conditions; and the second concave-convex structure 411 can be not set, and the first concave-convex structure 323 and the second concave-convex structure 411 can be combined in any way, without any specific limitation.

[0101] In addition, for the deep ultraviolet LED packaging structure 10 of this embodiment, compared with the packaging method in the first embodiment, the packaging method in this embodiment is different in that:

[0102] like Figure 8 As shown, the deep ultraviolet LED packaging method also includes the following steps:

[0103] S600: When the outer wall of the transparent cover plate 600 is located between the outer wall of the surrounding wall portion 410 and the outer wall of the frame body 320 (specifically, the outer wall of the second frame portion 322), that is, when the outer wall of the transparent cover plate 600 is located between the outer wall and the inner wall of the surrounding wall portion 410, or when the outer wall of the transparent cover plate 600 is located between the inner wall of the surrounding wall portion 410 and the outer wall of the frame body 320 (specifically, the outer wall of the second frame portion 322), a second colloid is applied to the top of the surrounding wall portion 410 to protect the transparent cover plate 600. After the second colloid is cured, the first protective portion 420 of the surrounding wall portion 410 is formed. The curing of the second colloid in step S600 can be performed simultaneously with the curing of the encapsulating colloid in step S500, or can be performed in two steps, depending on the actual situation. It should be noted that when the outer wall of the transparent cover 600 is located between the outer wall and the inner wall of the wall portion 410, the contact area between the transparent cover 600 and the encapsulation colloid will be larger, and it will also be in contact with the wall portion 410, which will help further improve the overall airtightness.

[0104] In addition, in some specific embodiments, when the retaining wall structure 400 also includes a second protective portion 430, in order to reduce packaging difficulty and ensure structural stability, it is usually necessary to solidify the second colloid into the first protective portion 420, and then, starting from the outer wall of the first protective portion 420, apply a third colloid to the top of the first protective portion 420 and the top surface of the transparent cover plate 600, and then solidify the third colloid to form the second protective portion 430. It should be noted that the material of the third colloid is usually the same as that of the second colloid, but of course it can be set to be different according to practical needs.

[0105] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be included within the scope of the claims of the present invention.

Claims

1. A deep ultraviolet LED packaging structure, characterized in that: The deep ultraviolet LED packaging structure includes a substrate, an LED unit, a metal frame, a retaining wall structure, a packaging adhesive layer and a transparent cover plate; the metal frame is enclosed on the front of the substrate to form a receiving cavity; A first pad group is provided on the front surface of the substrate, and the first pad group is located in the accommodating cavity and is insulated from the metal frame; The LED unit is in the accommodating cavity and is arranged on the first solder pad group; The metal frame includes a frame bottom and a frame body, wherein the frame bottom is arranged on the front surface of the substrate and is located outside the first pad group, and the frame body is arranged on the frame bottom; a step structure is formed between the outer side wall of the frame body and the frame bottom; The retaining wall structure is located at the periphery of the frame body, and the retaining wall structure includes a surrounding wall portion, the surrounding wall portion is arranged on the frame bottom, and a groove for filling the encapsulation colloid is formed between the surrounding wall portion and the metal frame; The encapsulation adhesive layer is formed by an encapsulation adhesive that fills the groove; The transparent cover is placed on the top of the metal frame. The portion of the transparent cover extending from the top of the frame is bonded to the metal frame and the surrounding wall through the packaging adhesive layer to seal the accommodating cavity.

2. The deep ultraviolet LED packaging structure according to claim 1, characterized in that: The top surface of the surrounding wall portion of the retaining wall structure is flush with the top surface of the frame body; the outer wall of the light-transmitting cover plate is flush with the outer wall of the surrounding wall portion.

3. The deep ultraviolet LED packaging structure according to claim 2, characterized in that: The surrounding wall portion of the retaining wall structure is formed by solidifying a light-proof colloid material.

4. The deep ultraviolet LED packaging structure according to claim 2, characterized in that: The surrounding wall portion of the retaining wall structure is integrally formed with the light-transmitting cover plate, and the surrounding wall portion and the light-transmitting cover plate are made of the same light-transmitting material.

5. The deep ultraviolet LED packaging structure according to claim 1, characterized in that: The retaining wall structure further includes a first protective portion, which is arranged on the top of the surrounding wall portion and is located outside the light-transmitting cover plate to cover the light-transmitting cover plate.

6. The deep ultraviolet LED packaging structure according to claim 5, characterized in that: The surrounding wall portion and the first protective portion of the retaining wall structure are solidified and formed separately or integrally, and both the surrounding wall portion and the first protective portion are solidified from a light-proof colloid material.

7. The deep ultraviolet LED packaging structure according to claim 1, characterized in that: A first concave-convex structure is formed on the outer side wall of the frame.

8. The deep ultraviolet LED packaging structure according to claim 1, characterized in that: A second concave-convex structure is formed on the inner side wall of the surrounding wall portion of the retaining wall structure.

9. The deep ultraviolet LED packaging structure according to claim 1, characterized in that: The thickness of the frame bottom ranges from 60 μm to 100 μm.

10. The deep ultraviolet LED packaging structure according to claim 1, characterized in that: A second pad group is provided on the reverse side of the substrate. The second pad group includes a middle pad and connecting pads located on opposite sides of the middle pad. The area of ​​the middle pad is 1.1 to 3 times the area of ​​the connecting pad.

11. A deep ultraviolet LED packaging method, characterized in that: The deep ultraviolet LED packaging method is used to package the deep ultraviolet LED packaging structure according to any one of claims 1 to 3 and 5 to 10, comprising the following steps: providing a metal frame on the front surface of the substrate; A first colloid is applied to the bottom of the metal frame at the periphery of the frame, and the first colloid forms the wall portion of the retaining wall structure after solidification; The groove formed between the wall portion and the frame is filled with encapsulating colloid; Placing a translucent cover plate on the top of the frame body, and making a portion of the translucent cover plate extend from the top of the frame body to contact the packaging colloid and cover the accommodating cavity where the LED unit is arranged; The encapsulating colloid is cured.

12. The deep ultraviolet LED packaging method according to claim 11, characterized in that: The LED packaging method further comprises the following steps: When the outer wall of the light-transmitting cover is located between the outer wall of the surrounding wall and the outer wall of the frame, a second colloid is applied to the top of the surrounding wall to protect the light-transmitting cover. After the second colloid is cured, the first protective portion of the surrounding wall is formed.

13. The deep ultraviolet LED packaging method according to claim 11, wherein: The viscosity of the first colloid used in the surrounding wall portion of the retaining wall structure is 3 to 10 times the viscosity of the encapsulating colloid.

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