CN114695622A

CN114695622A - Deep ultraviolet LED packaging structure and packaging method thereof

Info

Publication number: CN114695622A
Application number: CN202011644629.1A
Authority: CN
Inventors: 李玉容; 赵森; 梁平霞; 曾子恒; 麦家儿
Original assignee: Foshan NationStar Optoelectronics Co Ltd
Current assignee: Foshan NationStar Optoelectronics Co Ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2022-07-01

Abstract

The invention belongs to the technical field of LED packaging, and relates to a deep ultraviolet LED packaging structure and a packaging method thereof, wherein the deep ultraviolet LED packaging structure comprises 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 comprises a frame bottom and a frame body, the frame bottom is arranged on the front surface of the substrate and is positioned at the periphery of a 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 wall part of the retaining wall structure is arranged on the frame bottom, and a groove for filling the packaging colloid is formed between the wall part and the metal frame; the transparent cover plate is arranged on the top end of the frame body of the metal frame, and the part of the transparent cover plate, which extends out of the top end of the frame body, is bonded and packaged with the metal frame and the wall part through a packaging adhesive layer; the deep ultraviolet LED packaging structure has low requirement on the control of the dispensing amount, good air tightness and high stability, and is beneficial to improving the packaging efficiency of products and reducing the packaging cost.

Description

Deep ultraviolet LED packaging structure and packaging method thereof

Technical Field

The invention relates to the technical field of LED packaging, in particular to a deep ultraviolet LED packaging structure and a packaging method thereof.

Background

The deep ultraviolet LED is an LED product which applies deep ultraviolet light (UV-C light for short) and has a sterilization function. However, deep ultraviolet light has special requirements for packaging materials, and organic materials such as silica gel are easy to turn yellow and age after encountering deep ultraviolet light. The prior ultraviolet product mainly adopts a packaging technology of coating glue on the upper edge of a cup body with a cup ceramic substrate and then placing a plane quartz glass or a quartz lens, although the packaging technology can reduce the aging problem of organic materials and the failure problem caused by wet heat stress to a certain extent, the stability and the reliability of the product are ensured. However, in the process of practice, the inventor finds that the packaging technology has at least the following defects:

(1) when glue is coated on the upper edge of the cup body of the ceramic substrate with the cup, the glue dispensing head needs to run for a circle at a constant speed along the upper edge of the cup body, so that the glue dispensing efficiency is low, the glue dispensing amount is not easy to control, and the situation that the glue dispensing amount is large or small is often easy to occur; when the dispensing amount is large, the glue is easy to overflow and flow into the cup, the glue layer is cracked under the long-term irradiation of the deep ultraviolet light emitted by the chip, and the energy of the deep ultraviolet light is radiated to the glue body to easily cause light decay, so that the sterilization effect is weakened.

(2) During packaging, the quartz glass or quartz lens cover is easy to deviate or move out of the cup body, so that manual righting is needed, the packaging time consumption is long, the packaging efficiency is low, manpower and material resources are wasted, and the packaging cost is high.

Disclosure of Invention

The embodiment of the invention aims to provide a deep ultraviolet LED packaging structure, which is used for solving the technical problems that the existing packaging technology of a deep ultraviolet LED product is low in dispensing efficiency, light attenuation is easy to occur due to difficulty in controlling dispensing quantity, and the whole packaging efficiency is low and the packaging cost is high due to difficulty in aligning a cover plate.

In order to solve the technical problems, the following technical scheme is adopted:

the deep ultraviolet LED packaging structure comprises 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 surface of the substrate to form an accommodating cavity;

a first pad group is arranged on the front surface of the substrate, is positioned in the accommodating cavity and is insulated from the metal frame;

the LED unit is arranged in the accommodating cavity and arranged on the first bonding pad group;

the metal frame comprises a frame bottom and a frame body, the frame bottom is arranged on the front surface of the substrate and is positioned on the periphery of the first bonding 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 positioned on the periphery of the frame body and comprises a wall portion, the wall portion is arranged on the bottom of the frame body, and a groove for filling packaging colloid is formed between the wall portion and the metal frame;

the packaging adhesive layer is formed by molding packaging adhesive filled in the groove;

the light-transmitting cover plate is arranged on the top end of the frame body of the metal frame, and the part, extending out of the top end of the frame body, of the light-transmitting cover plate is bonded and packaged with the metal frame and the enclosing wall part through the packaging adhesive layer so as to seal the containing cavity.

In some embodiments, the top surface of the wall part 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.

Further, in some embodiments, the wall portion of the retaining wall structure is formed by curing a light-impermeable colloid material.

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

Or, in other embodiments, the retaining wall structure further includes a first protection portion, and the first protection portion is disposed on the top end of the surrounding wall portion and located at the periphery of the transparent cover plate to cover the transparent cover plate.

Further, in these embodiments, the wall portion and the first protection portion of the retaining wall structure are respectively formed by curing or integrally forming, and the wall portion and the first protection portion are formed by curing the opaque colloid material.

Further, in some embodiments described above, the first concave-convex structure is formed on an outer side wall of the frame body.

Further, in some embodiments of the foregoing, a second concave-convex structure is formed on an inner side wall of the wall portion of the retaining wall structure.

Further, in some of the above embodiments, the thickness of the frame bottom ranges from 60 μm to 100 μm.

Further, in some embodiments described above, a second pad group is disposed on the reverse side of the substrate, where the second pad group includes a middle pad and connection pads located on two opposite sides of the middle pad, and an area of the middle pad is 1.1 times to 3 times an area of the connection pads.

In order to solve the above technical problem, an embodiment of the present invention further provides a deep ultraviolet LED packaging method, which adopts the following technical scheme: the deep ultraviolet LED packaging method is used for packaging the deep ultraviolet LED packaging structure and comprises the following steps:

arranging a metal frame on the front surface of the substrate;

dotting a first colloid on the frame bottom at the periphery of the frame body of the metal frame, wherein the first colloid forms a wall part of the retaining wall structure after being solidified;

filling a groove formed between the surrounding wall part and the frame body with packaging colloid;

placing a light-transmitting cover plate on the top end of the frame body, enabling a part of the light-transmitting cover plate extending out of the top end of the frame body to be in contact with the packaging colloid, and covering an accommodating cavity provided with the LED unit;

and curing the packaging colloid.

In some embodiments, the deep ultraviolet LED packaging method further comprises the steps of:

the outer side wall of the light-transmitting cover plate is located between the outer side wall of the enclosure portion and the outer side wall of the frame body, a second glue body is dotted on the top end of the enclosure portion to protect the light-transmitting cover plate, and the first protection portion of the enclosure portion is formed after the second glue body is solidified.

In some embodiments, the viscosity of the first colloid used in the wall portion of the retaining wall structure is 3 times to 10 times that of the encapsulant.

Compared with the prior art, the deep ultraviolet LED packaging structure and the packaging method thereof provided by the embodiment of the invention have the following main beneficial effects:

this dark ultraviolet LED packaging structure passes through metal crate, barricade structure's enclosure portion encloses jointly to close and forms the recess that is used for filling the encapsulation colloid, and arrange the printing opacity apron in on the top of framework, need not be to the contact surface coating colloid of framework and printing opacity apron, but directly form the encapsulation glue film outside metal crate, do benefit to and promote encapsulation efficiency, and can reduce the technology degree of difficulty of some volume of gluing uncontrollable to a certain extent, concretely, on the one hand when the volume of gluing of encapsulation colloid is more, can ensure that the encapsulation colloid can not flow into the intracavity that holds that is packaged with the LED unit, avoid causing the light decay.

On the other hand, because the light-transmitting cover plate is mainly supported by the frame body of the metal frame, the light-transmitting cover plate only needs to extend out a part of the top end of the frame body towards the direction of the retaining wall structure, and in addition, the enclosing wall part is aligned well in advance, so that the light-transmitting cover plate is beneficial to effectively improving the alignment problem when the light-transmitting cover plate is covered, and is beneficial to improving the packaging efficiency of products and reducing the packaging cost.

In general, the deep ultraviolet LED packaging structure has good structural stability, high reliability and low control requirement on the dispensing amount; the corresponding packaging method is simple and reliable, and has high packaging efficiency and low cost.

Drawings

In order to illustrate the solution of the invention more clearly, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are some embodiments of the invention, and that other drawings may be derived from these drawings by a person skilled in the art without inventive effort. Wherein:

fig. 1 is a cross-sectional view of a deep ultraviolet LED package structure according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view of the fit between the substrate and the metal frame of the deep ultraviolet LED package structure of FIG. 1;

fig. 3 is a cross-sectional view of a deep ultraviolet LED package structure in a second embodiment of the invention;

fig. 4 is a cross-sectional view of a deep ultraviolet LED package structure in a third embodiment of the present invention;

fig. 5 is a cross-sectional view of another deep ultraviolet LED package structure in a third embodiment of the invention;

fig. 6 is a cross-sectional view of another deep ultraviolet LED package structure in a third embodiment of the invention;

FIG. 7 is a flowchart of a method for packaging a deep ultraviolet LED package structure according to an embodiment of the present invention;

fig. 8 is a flowchart of a packaging method of a deep ultraviolet LED packaging structure in the third embodiment of the present invention.

The reference numbers in the drawings are as follows:

10. a deep ultraviolet LED package structure;

100. a substrate; 110. a first pad group; 120. a second pad group; 121. an intermediate pad; 122. a connection pad;

200. an LED unit;

300. a metal frame; 310. a frame bottom; 320. a frame body; 321. a first frame portion; 322. a second frame portion; 323. a first relief structure; 330. a step structure;

400. a retaining wall structure; 410. a wall portion; 411. a second relief structure; 420. a first guard portion; 430. a second protection part;

500. packaging the adhesive layer; 600. a light-transmitting cover plate; 700. an accommodating chamber; 800. and (4) a groove.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; the terminology used in the description presented herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention, e.g., the terms "length," "width," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," "outer," etc., refer to an orientation or position based on that shown in the drawings, are for convenience of description only and are not to be construed as limiting of the present disclosure.

The terms "including" and "having," and any variations thereof, in the description and claims of this invention and the description of the above figures are intended to cover non-exclusive inclusions; the terms "first," "second," and the like in the description and in the claims, or in the drawings, are used for distinguishing between different objects and not necessarily for describing a particular sequential order. The meaning of "plurality" is two or more unless specifically limited otherwise.

In the description and claims of the present invention and in the description of the above figures, when an element is referred to as being "fixed" or "mounted" or "disposed" 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 can be directly or indirectly connected to the other element.

Furthermore, reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

It should be noted that the deep ultraviolet LED package structure 10 may be an LED sterilization device, and may also be an LED light source device, and of course, may also have other applications in other suitable fields. Note also that the "outer side wall" described below generally refers to a side wall on a side away from the LED unit 200; correspondingly, the "inner sidewall" described below generally refers to a sidewall near one side of the LED unit 200. The LED unit 200 is typically a deep ultraviolet chip, but may be other suitable deep ultraviolet LED units.

Embodiment one of the deep ultraviolet LED package structure 10 of the present invention

An embodiment of the invention provides a deep ultraviolet LED package structure 10, as shown in fig. 1, the deep ultraviolet LED package structure 10 includes a substrate 100, an LED unit 200, a metal frame 300, a retaining wall structure 400, a package adhesive layer 500, and a light-transmitting cover plate 600, wherein the metal frame 300 is disposed on a front surface of the substrate 100 and encloses to form a containing cavity 700. As further shown in fig. 1 and fig. 2, the front surface of the substrate 100 is provided with a first pad group 110, wherein the first pad group 110 is located in the accommodating cavity 700 and insulated from the metal frame 300. The LED unit 200 is disposed on the first pad group 110 within the receiving cavity 700.

In addition, in order to realize the electrical connection of the deep ultraviolet LED package structure 10 and enable the LED unit 200 to work normally, a second pad group 120 is generally disposed on the reverse side of the substrate 100, wherein the second pad group 120 includes an intermediate pad 121 and a connection pad 122, and the connection pads 122 are disposed on two opposite sides of the intermediate pad 121. Specifically, in this embodiment, the intermediate pad 121 is mainly used for dissipating heat generated during operation of the chip; the connection pads 122 are electrically connected to the first pad set 110, and are mainly used for electrically connecting the chip and an external circuit.

As shown in fig. 1 and 2, the metal frame 300 includes a frame bottom 310 and a frame body 320, wherein the frame bottom 310 is disposed on the front surface of the substrate 100 and located at the periphery of the first pad set 110, the frame body 320 is disposed on the top surface of the frame bottom 310, a step structure 330 is formed between the outer sidewall of the frame body 320 and the frame bottom 310, and the inner sidewall of the frame body 320 is flush with the inner sidewall of the frame bottom 310. In this embodiment, the bottom area of the frame 320 is smaller than the top area of the frame bottom 310, and the height of the frame 320 is greater than the thickness of the frame bottom 310. The frame bottom 310 and the frame body 320 are made of metal material, and they can be integrally formed or separately arranged.

In addition, as shown in fig. 2, in order to ensure the thermal balance of the front and back sides of the substrate and prevent the substrate from deforming, and to reserve enough accommodating space for the adhesive layer of the package so as to ensure the bonding effect of the package, the bottom width b2 of the frame body is 0.3-0.7 times of the width b1 of the frame bottom, and b1-b2 is greater than or equal to 100 μm, and the thickness range of the frame bottom 310 is 60-100 μm. Specifically, in the present embodiment, the area of the intermediate pad 121 is 1.1 to 3 times the area of the connection pad 122.

In the present embodiment, as shown in fig. 1, the retaining wall structure 400 is located at the periphery of the frame body 320, wherein 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, and the groove 800 is used for filling the encapsulant. The encapsulant fills the recess 800 and is formed (e.g., cured) to form the encapsulant layer 500. It can be understood that the wall portion 410 of the retaining wall structure 400 is disposed at a gap from the frame body 320 of the metal frame 300, and specifically, the wall portion 410, the frame body 320 and the frame bottom 310 together enclose the groove 800.

In the present embodiment, as shown in fig. 1, in order to facilitate forming the recess 800 and ensure that the retaining wall structure 400 is not cut when the subsequent cutting is separated into individual devices, the retaining wall portion 410 is disposed 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, by disposing the frame bottom 310 and disposing the frame body 320 on the frame bottom 310, the positioning of the dispensing head on the starting point of the wall portion 410 and the identification and positioning of the dispensing head can be facilitated when the retaining wall structure 400 is formed in the packaging process.

In the present embodiment, as shown in fig. 1, the light-transmitting cover plate 600 is disposed on the top end of the frame body 320 of the metal frame 300, and the portion of the light-transmitting cover plate 600 extending out of the top end of the frame body 320 is bonded and packaged with the metal frame 300 and the wall portion 410 by the packaging adhesive layer 500 to seal the accommodating cavity 700.

For convenience of description, as shown in fig. 2, the first pad group 110 and the metal frame 300 may be collectively referred to as a first metal layer (not shown) disposed on the front surface of the substrate 100, and correspondingly, the metal layer formed by the second pad group 120 may be referred to as a second metal layer (not shown) disposed on the back surface of the substrate 100. It can be understood that, by providing the metal stepped metal frame 300 on the front side of the substrate 100 (for example, the metal frame 300 is formed with the first concave-convex structure 323 and the step structure 330), the volume of the first metal layer on the front side of the substrate 100 can be reduced, and in the heating process of the package curing, the heat absorption of the first metal layer is favorably reduced, so that the heat balance between the front side and the back side of the substrate 100 is achieved, and the substrate 100 is ensured not to be deformed due to uneven heating of the front side and the back side. In addition, the frame bottom 310 of the metal frame 300 disposed on the front surface of the substrate 100 may further increase the contact area between the first metal layer and the front surface of the substrate 100 to a certain extent, which is beneficial to improving the heat dissipation performance of the first metal layer.

It should be noted that, in this embodiment, the top end of the frame 320 does not need to be glued, and in order to ensure that the transparent cover plate 600 can be placed flatly, the top surface of the frame 320 may be slightly higher than or equal to the top surface of the surrounding wall portion 410, wherein the height difference between the two ranges within 100 μm. The light-transmissive cover 600 is mainly supported by the frame body 320 of the metal frame 300. The light-transmitting cover plate 600 is made of a material having high light transmittance to deep ultraviolet, such as glass, quartz glass, or the like.

In summary, compared with the prior art, the deep ultraviolet LED package structure 10 at least has the following beneficial effects: this deep ultraviolet LED packaging structure 10 passes through metal frame 300, the enclosure portion 410 of barricade structure 400 encloses jointly and closes the recess 800 that forms and be used for filling the encapsulation colloid, and place printing opacity apron 600 on the top of framework 320, need not be to framework 320 and printing opacity apron 600's contact surface coating colloid, but directly form encapsulation glue film 500 outside metal frame 300, do benefit to and promote encapsulation efficiency, and can reduce the difficult technological degree of control of volume of dispensing to a certain extent, specifically, on the one hand when the volume of dispensing is more at the encapsulation colloid, can ensure that the encapsulation colloid can not flow into the chamber 700 that holds that is encapsulated with LED unit 200, avoid causing the light decay.

On the other hand, since the transparent cover 600 is mainly supported by the frame 320 of the metal frame 300, the transparent cover 600 only needs to extend a portion from the top end of the frame 320 toward the retaining wall structure 400, and in addition, the enclosing wall 410 is aligned in advance, which is beneficial to effectively improving the alignment problem when the transparent cover 600 is covered, and is beneficial to improving the packaging efficiency of the product and reducing the packaging cost. Especially, when the outer sidewall of the transparent cover 600 is located at the inner side of the enclosing wall 410, the enclosing wall 410 has a limiting effect on the transparent cover 600, which is beneficial to further improving the alignment accuracy of the transparent cover 600.

In general, the deep ultraviolet LED package structure 10 has good structural stability, high reliability, high packaging efficiency, and low control requirement for dispensing amount.

In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to fig. 1 and fig. 2.

Further, in some embodiments of the present invention, as shown in fig. 1, to ensure that the light-transmitting cover plate 600 can be placed flatly, 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 enclosure portion 410 and the frame 320 is uniform. As shown in fig. 1 again, in order to form a single package structure, the outer sidewall of the transparent cover 600 extends beyond the inner sidewall of the enclosure portion 410, preferably, the outer sidewall of the transparent cover 600 is flush with the outer sidewall of the enclosure portion 410, and actually, the outer sidewall of the transparent cover 600 may also be located between the outer sidewall and the inner sidewall of the enclosure portion 410. It will be appreciated that the light-transmissive cover 600 is supported by the enclosure portion 410 and the frame 320, which is beneficial to ensure the stability of the whole structure.

Specifically, in the present embodiment, the wall portion 410 of the retaining wall structure 400 is formed by curing a non-light-transmissive colloid material.

Further, in some embodiments of the present embodiment, the outer side wall surface of the frame body 320 is a vertical surface, so as to increase the adhesion between the encapsulant 500 and the metal frame 300 and increase the contact area between the encapsulant 500 and the metal frame 300, the outer side wall surface of the frame body 320 may have other structures such as an inclined surface, a curved surface, and a stepped surface. Specifically, as shown in fig. 1, a first concave-convex structure 323 is formed on an outer side wall of the frame body 320. The specific shape of the first concave-convex structure 323 can be determined according to actual needs.

It can be understood that when the dispensing amount of the encapsulant is small, by disposing the first concave-convex structure 323 on the outer sidewall of the metal frame 300 and forming the step structure 330 between the frame body 320 and the frame bottom 310, when the dispensing amount of the encapsulant is small, it can be ensured that the retaining wall structure 400, the metal frame 300, the transparent cover plate 600 and the encapsulant layer 500 can be bonded more firmly, so as to ensure the air tightness of the outer sidewall and the top sidewall of the metal frame 300, and there is no need to worry about the moisture entering into the accommodating cavity 700.

Further, in some specific embodiments in this embodiment, as shown in fig. 1, the first concave-convex structure 323 is a step in a right-angle shape; alternatively, the first concave-convex structure 323 has a step of a rounded shape, but may have other suitable concave-convex structures, for example, a portion of the outer wall surface of the frame 320 may have an inclined surface, a curved surface, or the like. In this embodiment, as shown in fig. 1, the first concave-convex structure 323 is 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, the second frame portion 322 is disposed on the first frame portion 321, an inner sidewall of the first frame portion 321 is flush with an inner sidewall of the second frame portion 322, and the top end of the second frame portion 322 is placed with the light-transmitting cover plate 600. On the side away from the LED unit 200, the joint between the first frame portion 321 and the second frame portion 322 is a rectangular 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 100 μm.

For example, in another embodiment, as shown in fig. 6, when the first concave-convex structure 323 has a step of a rounded shape, the arc radius R is 1/10 to 2/3 times the width L of the frame bottom. It can be understood that, through setting up the circular arc structure, can be so that the contact of packing colloid and first concave-convex structure 323 is a relatively smooth face, like this, is the step of right angle form for first concave-convex structure 323, and the packing colloid can be inseparabler with the contact of first concave-convex structure 323, does benefit to the cohesiveness that improves between packing colloid and the framework 320.

Further, in some embodiments of the present invention, as shown in fig. 1, in order to enhance the adhesion between the encapsulating adhesive layer 500 and the wall portion 410 and further improve the air tightness of the package structure, a second concave-convex structure 411 is formed on the inner sidewall of the wall portion 410 of the retaining wall structure 400. It should be noted that, in this embodiment, specifically, the second concave-convex structure 411 is located on the top of the first concave-convex structure 323 and is disposed opposite to the first concave-convex structure 323, that is, a cross structure is formed between the second concave-convex structure 411 and the first concave-convex structure 323, so that, by staggering and crossing the second concave-convex structure 411 and the first concave-convex structure 323, the adhesion between the encapsulant and the frame 320 and the enclosure part 410 is further improved.

The embodiment of the present invention further provides a deep ultraviolet LED packaging method, wherein the deep ultraviolet LED packaging method is used for packaging the deep ultraviolet LED packaging structure 10 in the embodiment, as shown in fig. 7, and the deep ultraviolet LED packaging method includes the following steps:

s100: a metal frame 300 is disposed on the front surface of the substrate 100. Specifically, in this embodiment, the outer sidewall of the metal frame 300 has the first concave-convex structure 323, but actually, the outer sidewall of the metal frame 300 may also have other structures such as a vertical surface, an inclined surface, a curved surface, and a stepped surface.

In step S100, the substrate 100 and the metal frame 300 may be directly assembled together to form a stand. In addition, the substrate 100 is also provided with a first pad group 110 and a second pad group 120. It should be noted that after step S100, the LED unit 200 may be flip-chip mounted in the metal frame 300, and the LED unit 200 may be soldered on the first pad group 110 on the front surface of the substrate 100 by eutectic soldering or the like.

S200: a first adhesive is applied to the frame bottom 310 at the periphery of the frame body 320 of the metal frame 300, and the first adhesive is cured to form the wall portion 410 of the retaining wall structure 400.

It should be noted that, during dispensing, the first colloid may be dispensed on the frame bottom 310 by using the outer sidewall of the frame bottom 310 as a dispensing starting point of the dispenser, wherein preferably, the viscosity of the first colloid adopted by the wall portion 410 of the retaining wall structure 400 is 3 times to 10 times that of the encapsulant. Preferably, the viscosity of the first colloid ranges from 40000mPa.s to 70000 mPa.s. In addition, the first colloid can be cured at normal temperature or heated. The shape of the wall portion 410 formed after curing may be square, circular, or other suitable shapes. Correspondingly, the frame bottom 310 and the frame body 320 of the metal frame 300 may have a square or circular shape, or may have other suitable shapes, and the shape of the frame bottom 310 and the frame body 320 is generally adapted to the shape of the surrounding wall portion 410.

Specifically, in one embodiment of the present invention, the first colloid is cured by heating and curing, wherein the curing temperature is in a range of 60 ℃ to 150 ℃, and specifically, the temperature is preferably in a range of 60 ℃ to 100 ℃ (i.e., low temperature curing). It should be noted that, because the curing temperature range of 60 ℃ to 100 ℃ is relatively low, the first colloid can be immediately cured under the action of the heating table by arranging the heating table below the substrate 100, and the first colloid does not need to be placed into an oven for baking, so that the packaging efficiency is improved. The curing time is generally 15 to 30min, and specifically, the curing time is preferably 5 to 15 min.

S300: the groove 800 formed between the wall portion 410 and the frame 320 is filled with a molding compound.

The encapsulant may be a solid encapsulant or a liquid encapsulant. When the encapsulant is in a liquid state, the encapsulant is dispensed into the recess 800 by a dispensing device. Specifically, in order to improve the dispensing efficiency, dispensing may be performed at individual positions above the groove 800 by a dispensing apparatus without performing circumferential dispensing. Taking the groove as a square as an example, the dispensing equipment can directly dispense at four corners of the groove 800. The encapsulant may be a material such as silicone, or the like.

S400: the transparent cover plate 600 is placed on the top end of the frame body 320, and a part of the transparent cover plate 600 extending from the top end of the frame body 320 is in contact with the encapsulant and covers the accommodating cavity 700 provided with the LED unit 200. The material of the light-transmitting cover plate 600 may be glass, quartz glass, or other materials having high light-transmitting property to UVC.

S500: and curing the packaging colloid. After curing, the encapsulating adhesive layer 500 is formed, and the enclosing 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 transparent cover plate 600 can be encapsulated together to form a whole through the encapsulating adhesive layer 500. In this embodiment, the encapsulant is cured in stages, where the curing temperature of the first curing process is 70-100 ℃, the curing time is 1 h-3 h, the curing temperature of the second curing process is 130-160 ℃, and the curing time is 2 h-5 h. In fact, of course, various parameters during curing can be adjusted according to actual needs.

In the packaging process, a plurality of metal frames 300 are usually disposed on one substrate 100, and thus a plurality of deep ultraviolet LED package units are formed through a cutting and separating process.

Generally, the deep ultraviolet LED packaging method provided by the embodiment of the invention is simple and reliable, and has high packaging efficiency and low cost.

Second embodiment of the deep ultraviolet LED package structure 10 of the present invention

Referring to fig. 3, the main technical features of the present embodiment are substantially the same as those of the first embodiment, and the main differences from the first embodiment are as follows:

in some embodiments of the present invention, as shown in fig. 3, the wall portion 410 of the retaining wall structure 400 is integrally formed with the light-transmissive cover plate 600, and the wall portion 410 and the light-transmissive cover plate 600 are made of the same light-transmissive material. Preferably, the enclosure portion 410 and the transparent cover plate 600 are made of glass, quartz glass, etc., i.e., customized special glass will be used. Specifically, in the present embodiment, the surrounding wall portion 410 is formed with the second concave-convex structure 411.

Compared with the encapsulation method in the first embodiment, the encapsulation method in the first embodiment is different in that: the first concave-convex structure 323 and the step structure 330 of the metal frame 300 are covered with the encapsulant, and then the transparent cover plate 600 is covered on the metal frame 300 and supported by the metal frame 300, and then the encapsulant is cured to form an integral body.

As can be understood from the above, since the light-transmitting cover plate 600 and the enclosing wall portion 410 are integrally formed, the light-transmitting cover plate 600 can be effectively prevented from being deviated or moving out of the enclosing wall portion 410, and the packaging process using such a structure is simplified.

Third embodiment of the deep ultraviolet LED package structure 10 of the present invention

Referring to fig. 4 to fig. 6, the main technical features of the present embodiment are substantially the same as those of the first embodiment, and the main differences from the first embodiment are as follows:

further, in some embodiments provided in this embodiment, as shown in fig. 4 to fig. 6, when the outer sidewall of the light-transmitting cover plate 600 is located inside the outer sidewall of the retaining wall structure 400, that is, between the outer sidewall of the surrounding wall portion 410 and the outer sidewall of the frame body 320 of the metal frame 300, the retaining wall structure 400 further includes a first protection portion 420, wherein the first protection portion 420 is disposed on the top end of the surrounding wall portion 410 and located at the periphery of the light-transmitting cover plate 600 to cover the light-transmitting cover plate 600, so that the outer sidewall of the light-transmitting cover plate 600 can be effectively protected to prevent the light-transmitting cover plate 600 from being broken.

Preferably, in some embodiments provided in this embodiment, the enclosing wall portion 410 and the first protection portion 420 of the retaining wall structure 400 are respectively formed by curing or integrally forming, and both the enclosing wall portion 410 and the first protection portion 420 are formed by curing the opaque colloid material. It should be noted that, as shown in fig. 4 to fig. 6, the retaining wall structure 400 may further include a second protection portion 430, wherein the second protection portion 430 is disposed at the end of the first protection portion 420 and is located on the top of the transparent cover plate 600, and obviously, by disposing the second protection portion 430, the problem that the transparent cover plate 600 is fragile during packaging can be further avoided, and meanwhile, the air tightness of the package structure is further improved. It should be noted that, when the retaining wall structure 400 includes the enclosing wall portion 410, the first protection portion 420 and the second protection portion 430, the enclosing wall portion 410 and the first protection portion 420 may be integrally formed, and then the second protection portion 430 is formed on the first protection portion 420 by curing, or the three may be formed by sequentially curing. When the retaining wall structure 400 includes the wall portion 410 and the first protection portion 420, the two portions may be integrally formed, or may be sequentially formed by curing, and the specific requirement may be determined according to the actual requirement.

Note that, as shown in fig. 4, the second concave-convex structure 411 is not used in the wall portion 410, and a right-angle transition is directly used, and the first concave-convex structure 323 on the metal frame 300 is a step having a right-angle shape, and the corner is not chamfered. As shown in fig. 5, the second concave-convex structure 411 is not used in the wall portion 410, and a fillet transition is directly used, the first concave-convex structure 323 on the metal frame 300 is a step in a right-angled shape, and a corner is rounded. As shown in fig. 6, the second concave-convex structure 411 is employed as the wall portion 410, and the circular arc structure is employed as it is, and the first concave-convex structure 323 on the metal frame 300 is a step having a circular angle shape. Specifically, the circular arc is directly provided on the second frame portion 322 of the frame body 320, while the first frame portion 321 is not changed.

It is understood that, in each embodiment of the present invention, the first concave-convex structure 323 and the second concave-convex structure 411 may adopt a right-angled step, and may also adopt a round-angled step, and the specific structure may be determined according to actual situations; also, the second concave-convex structure 411 may not be provided, and the first concave-convex structure 323 and the second concave-convex structure 411 may be provided in combination in any manner, without particular limitation.

In addition, compared with the first packaging method, the packaging method of the present embodiment of the deep ultraviolet LED package structure 10 of the present embodiment is different in that:

as shown in fig. 8, the deep ultraviolet LED packaging method further includes the following steps:

s600: when the outer sidewall of the transparent cover plate 600 is located between the outer sidewall of the wall portion 410 and the outer sidewall of the frame body 320 (specifically, the outer sidewall of the second frame portion 322), that is, when the outer sidewall of the transparent cover plate 600 is located between the outer sidewall and the inner sidewall of the wall portion 410, or located between the inner sidewall of the wall portion 410 and the outer sidewall of the frame body 320 (specifically, the outer sidewall of the second frame portion 322), a second sealant is dotted on the top end of the wall portion 410 to protect the transparent cover plate 600, and the second sealant is cured to form the first protective portion 420 of the wall portion 410. The curing of the second encapsulant in step S600 may be performed simultaneously with the curing of the encapsulant in step S500, or may be performed twice in sequence, which may be determined according to actual conditions. It should be noted that, when the outer sidewall of the transparent cover 600 is located between the outer sidewall and the inner sidewall of the enclosure portion 410, the contact area between the transparent cover 600 and the encapsulant is larger, and the transparent cover is also in contact with the enclosure portion 410, so that the overall airtightness is further improved.

In addition, in some embodiments, when the retaining wall structure 400 further includes the second protection portion 430, in order to reduce the packaging difficulty and ensure the structural stability, usually, after the second glue is cured and molded into the first protection portion 420, the outer sidewall of the first protection portion 420 is taken as a starting point, a third glue is applied to the top end of the first protection portion 420 and the top surface of the transparent cover plate 600, and then the third glue is cured and molded into the second protection portion 430. It should be noted that the material of the third colloid is generally the same as that of the second colloid, but may be different from the second colloid.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A deep ultraviolet LED packaging structure is characterized by comprising a substrate, LED units, 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 surface of the substrate to form an accommodating cavity;

2. The deep ultraviolet LED package structure of claim 1, wherein the top surface of the wall portion of the retaining wall structure is flush with the top surface of the frame; 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 package structure of claim 2, wherein the wall portion of the retaining wall structure is formed by curing an opaque adhesive material.

4. The deep ultraviolet LED package structure of claim 2, wherein the wall portion of the retaining wall structure and the light-transmitting cover plate are integrally formed, and the wall portion and the light-transmitting cover plate are made of the same light-transmitting material.

5. The deep ultraviolet LED package structure of claim 1, wherein the retaining wall structure further comprises a first protection portion, the first protection portion is disposed on a top end of the retaining wall portion and located at a periphery of the light-transmitting cover plate to cover the light-transmitting cover plate.

6. The deep ultraviolet LED package structure of claim 5, wherein the wall portion and the first protection portion of the wall structure are respectively formed by curing or integrally forming, and the wall portion and the first protection portion are formed by curing a non-light-tight colloid material.

7. The deep ultraviolet LED package structure of claim 1, wherein a first concave-convex structure is formed on an outer sidewall of the frame body.

8. The deep ultraviolet LED package structure of claim 1, wherein a second concave-convex structure is formed on an inner sidewall of the wall portion of the retaining wall structure.

9. The deep ultraviolet LED package structure of claim 1, wherein the frame bottom has a thickness ranging from 60 μm to 100 μm.

10. The deep ultraviolet LED package structure of claim 1, wherein a second bonding pad set is disposed on the reverse side of the substrate, the second bonding pad set comprises a middle bonding pad and connection bonding pads disposed on two opposite sides of the middle bonding pad, and the area of the middle bonding pad is 1.1-3 times that of the connection bonding pads.

11. A deep ultraviolet LED packaging method for packaging the deep ultraviolet LED packaging structure of any one of claims 1 to 3 and 5 to 10, comprising the following steps:

arranging a metal frame on the front surface of the substrate;

and curing the packaging colloid.

12. The deep ultraviolet LED packaging method of claim 11, further comprising the steps of:

when the outer side wall of the light-transmitting cover plate is located between the outer side wall of the wall portion and the outer side wall of the frame body, a second colloid is dotted on the top end of the wall portion to protect the light-transmitting cover plate, and the first protection portion of the wall portion is formed after the second colloid is solidified.

13. The method according to claim 11, wherein the viscosity of the first encapsulant adopted by the wall portion of the dam structure is 3 times to 10 times the viscosity of the encapsulant.