Deep ultraviolet LED packaging structure and deep ultraviolet LED packaging method
By setting up dispensing grooves, overflow grooves and overflow channels in the deep ultraviolet LED packaging structure, the uneven distribution of adhesives and airway problems are solved, and a higher quality packaging effect is achieved.
Patent Information
- Application Number
- CN202411737164.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-03-18
AI Technical Summary
In the existing deep ultraviolet LED packaging methods, the adhesive is unevenly distributed, and the airway is prone to occur, resulting in low product quality.
It adopts a deep UV LED packaging structure, including surrounding brackets and assembly grooves, and sets dispensing grooves, overflow grooves and overflow channels to ensure uniform distribution and sealing of the glue.
Through the design of overflow grooves and overflow channels, excessive overflow of adhesive is avoided, adhesive uniformity is ensured, airways are prevented, and product quality is improved.
Smart Images
Figure CN119653945A_ABST
Abstract
Description
Technical Field
[0001] The present invention specifically relates to a deep ultraviolet LED packaging structure and a deep ultraviolet LED packaging method. Background Art
[0002] In recent years, with the progress of semiconductor material science, Deep Ultraviolet Light Emitting Diode (DUV LED), or deep ultraviolet LED, has attracted more and more attention due to its wide application in sterilization, photocuring, biomedicine and other fields. At present, the common deep ultraviolet LED packaging methods on the market mainly include resin packaging, ceramic packaging, etc., but the deep ultraviolet LED chip technology is not very mature and the chip reliability is poor, so the packaging requirements are relatively high, and a packaging method with high airtightness is required. At present, for low-power deep ultraviolet LED chips, high-cost inorganic packaging is used, but it is difficult to achieve good market applications due to the high cost. Therefore, a more cost-effective semi-inorganic packaging is used, that is, the light-emitting surface uses a quartz glass lens with good transmittance to deep ultraviolet light, and an organic glue is used to bond the glass and the bracket. Although this solution has the above-mentioned advantages such as low cost and high light output efficiency, the general deep ultraviolet LED bracket adopts a multi-layer copper-plated bracket solution on ceramic, which will form uneven steps or burrs at the edge of the step. When covering the lens, it is easy to cause uneven distribution of adhesive due to uneven steps and edge burrs, thereby causing airways.
[0003] The present invention is just produced based on the above-mentioned shortcomings. Summary of the invention
[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a deep ultraviolet LED packaging structure and a deep ultraviolet LED packaging method, both of which are for improving the uniformity of adhesion, avoiding the formation of airways in the adhesive, and thus improving product quality.
[0005] The present invention is achieved through the following technical solutions:
[0006] The present invention provides a deep ultraviolet LED packaging structure, comprising a substrate and a bracket connected to the upper surface of the substrate, the bracket is in a surrounding structure and a crystal solid cavity is formed in the middle to facilitate the placement of a light-emitting element in the crystal solid cavity, the upper surface of the bracket is provided with an assembly groove which is arranged around the crystal solid cavity and is used to place a lens, the bracket is provided with a glue dispensing groove which surrounds the crystal solid cavity on the bottom of the assembly groove, the bracket is also provided with an overflow groove which surrounds the glue dispensing groove on the bottom of the assembly groove, and a plurality of overflow channels which connect the glue dispensing groove and the overflow groove are provided between the glue dispensing groove and the overflow groove.
[0007] As described above, the deep ultraviolet LED packaging structure, the bracket includes a base, the upper surface of the base is provided with an edge ring plate extending upward, the edge ring plate and the base form the assembly groove, the upper surface of the base is also provided with a middle convex ring located on the inner side of the edge ring plate, and an inner convex ring located on the inner side of the middle convex ring, the middle convex ring and the inner convex ring form the glue dispensing groove, the middle convex ring and the edge ring plate form the overflow groove, and the middle convex ring is provided with a plurality of notches to form the overflow channel.
[0008] In the deep ultraviolet LED packaging structure as described above, the height of the middle convex ring is less than or equal to the height of the inner convex ring.
[0009] The deep ultraviolet LED packaging structure as described above is characterized in that the bottom of the glue dispensing groove is lower than the bottom of the overflow groove.
[0010] The present invention also provides a deep ultraviolet LED packaging method, which uses a deep ultraviolet LED packaging structure according to claim 1 and comprises the following steps:
[0011] S1. Use the glue dispenser to dispense glue along the glue dispensing slot;
[0012] S2, heating the deep ultraviolet LED packaging structure, and placing a lens in the assembly groove 20 to form a blank;
[0013] S3, placing the blank in step S2 in an oven for baking;
[0014] S4, placing the blank in a high temperature oven and baking it at high temperature to make a finished product.
[0015] In the deep ultraviolet LED packaging method as described above, step S2 includes the following sub-steps:
[0016] S21, before placing the lens, blowing hot air downward from above the deep ultraviolet LED packaging structure, so as to increase the temperature of the air in the crystal bonding cavity;
[0017] S22. Place a lens in the assembly groove, and continue to blow hot air downward from above the deep ultraviolet LED packaging structure, thereby continuously heating the deep ultraviolet LED packaging structure to keep the air temperature in the crystal bonding cavity stable.
[0018] In the deep ultraviolet LED packaging method as described above, in step S21 and step S22, the hot air temperature is maintained below 100°C.
[0019] In the deep ultraviolet LED packaging method as described above, the bottom of the dispensing groove is lower than the bottom of the overflow groove, and before step S3, the blank is vacuumed.
[0020] In the deep ultraviolet LED packaging method as described above, the baking temperature in step S3 is T1, and the hot air heating temperature in step S2 is T2, then T1-T2≤10°C.
[0021] In the deep ultraviolet LED packaging method as described above, the bottom of the dispensing groove gradually decreases from the outside to the inside, the bottom of the overflow groove gradually decreases from the outside to the inside, and the bottom surface of the overflow channel gradually decreases from the outside to the inside.
[0022] Compared with the prior art, the present invention has the following advantages:
[0023] The deep ultraviolet LED packaging structure of the present invention and the packaging method using the structure are to open two groove structures for accommodating glue on the packaging structure, so that the excess glue can overflow to the overflow groove through the overflow channel before and after the lens is placed and installed, so that a circle of sealant structure with good sealing performance is formed on the lower side of the lens, while avoiding excessive glue overflowing to the edge or middle of the lens, and preventing the occurrence of air ducts due to uneven steps on the edge of the packaging structure, edge burrs, etc. while ensuring the uniformity of the product glue, thereby ensuring the quality of the product. At the same time, since the traditional semi-inorganic packaging method uses a flat table for glue connection, the glue can form a bond with the rigid lens and the flat table of the bracket during the heating and curing process, but the glue will shrink during the cooling process after curing, and the bonded lens and bracket are rigid, so it is very easy to cause the glue shrinkage and the bonding surface to debond; this scheme sets an overflow groove and an overflow channel, so that the soft glue has enough space to expand in the direction of the overflow groove and the overflow channel during high-temperature curing, and the expanded glue can shrink in an orderly manner when the temperature drops, thereby effectively preventing the debonding phenomenon that occurs in the traditional bonding method. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a schematic diagram of the principle of the deep ultraviolet LED packaging structure of the present invention;
[0025] Figure 2 is a top view schematic diagram of a deep ultraviolet LED packaging structure of the present invention;
[0026] Figure 3 It is a schematic diagram of the steps of the deep ultraviolet LED packaging method of the present invention;
[0027] Figure 4 yes Figure 2 Sectional view at AA;
[0028] Figure 5 yes Figure 2 Cross-sectional view at BB;
[0029] Figure 6 1 is a schematic diagram of the structure of a third embodiment of a deep ultraviolet LED packaging structure of the present invention;
[0030] Figure 7 1 is a cross-sectional schematic diagram of a third embodiment of a deep ultraviolet LED packaging structure of the present invention;
[0031] Figure 8 It is a top view schematic diagram of the fourth embodiment of the deep ultraviolet LED packaging structure of the present invention. DETAILED DESCRIPTION
[0032] The invention will be further described below in conjunction with the accompanying drawings:
[0033] The directions described in the specification of the present invention, such as "up", "down", "left", "right", "front", "back", etc., are based on the directions of the drawings and are intended to facilitate the description of the relationship between the various components. They do not indicate the unique or absolute positional relationship between the various components. They are only one of the implementation methods of the invention and are not a limitation on its implementation method.
[0034] Embodiment 1
[0035] The present invention provides a method for packaging a deep ultraviolet LED, wherein a deep ultraviolet LED packaging structure is used, such as Figure 1 and Figure 2 As shown, the type includes a substrate 1 and a bracket 2 connected to the upper surface of the substrate 1, the bracket 2 is a surrounding structure and a solid crystal cavity 10 is formed in the middle to facilitate the arrangement of the light-emitting element A in the solid crystal cavity 10. Generally, the light-emitting element A is pre-installed in the solid crystal cavity 10 on the substrate 1, and the upper surface of the bracket 2 is provided with an assembly groove 20 arranged around the solid crystal cavity 10 and used to place the lens B. The bracket 2 is provided with a dispensing groove 21 surrounding the solid crystal cavity 10 on the bottom of the assembly groove 20, and the bracket 2 is also provided with an overflow groove 22 surrounding the dispensing groove 21 on the bottom of the assembly groove 20, and the dispensing groove 21 and the overflow groove 22 A plurality of overflow channels 23 are provided to connect the two, so that during processing, glue is first dispensed along the glue dispensing groove 21, so that excess glue overflows to the overflow groove 22 through the overflow channel 23, and then the lens B is placed in the assembly groove 20. After the lens B is placed and installed, the excess glue can also overflow to the overflow groove 22 through the overflow channel 23, so that a circle of well-sealed sealant structure is formed on the lower side of the lens B, while preventing excessive glue from overflowing to the edge or middle of the lens B. While ensuring uniform gluing of the product, it prevents the formation of airways due to uneven steps on the edge of the packaging structure, edge burrs, etc., thereby ensuring product quality.
[0036] In more detail, Figure 1 and Figure 2As shown, the specific structure of the bracket 2 includes a base 24, an upper surface of the base 24 is provided with an edge ring plate 25 extending upward, the edge ring plate 25 and the base 24 form the assembly groove 20, the upper surface of the base 24 is also provided with a middle convex ring 26 located on the inner side of the edge ring plate 25, and an inner ring convex ring 27 located on the inner side of the middle convex ring 26, the middle convex ring 26 and the inner ring convex ring 27 form the dispensing groove 21, the middle convex ring 26 and the edge ring plate 25 form the overflow groove 22, and the middle convex ring 26 is provided with a plurality of notches to form the overflow channel 23. In the present embodiment, a soft baking process is adopted in the process of manufacturing the deep ultraviolet LED packaging structure, that is, a relatively low temperature preheating is adopted. It is known that during soft baking, the gas in the solid crystal cavity heats up and expands, which may cause a gas channel to easily appear in the adhesive. The packaging structure of the present patent is provided with an overflow channel. Since the overflow resistance at the overflow channel is small when the gas expands, the expanded and overflowed gas basically overflows through the overflow channel, forming a gas channel at the overflow channel. Due to the design of the overflow groove, when the air temperature in the solid crystal cavity is stable, the air pressure is stable, and the gas no longer expands. At this time, the glue in the overflow groove can flow back through the overflow channel again, thereby filling and sealing the generated gas channel.
[0037] As a preferred embodiment, Figure 1 and Figure 2 As shown, the height of the middle convex ring 26 is less than or equal to the height of the inner convex ring 27. Since the glue is slightly convex after dispensing, when covering the lens B, the glue will flow outwards due to the existence of internal air pressure when covering the lens B. When the efficiency of the glue flowing to the overflow groove 22 through the overflow channel 23 is not enough, in order to prevent the glue from overflowing inwards across the inner convex ring 27, the glue is made to overflow outwards across the middle convex ring 26. In addition, the bottom of the dispensing groove 21 can also be designed to be lower than the bottom of the overflow groove 22. With this design, after the gas channel appears in the early stage of soft baking, the fluidity of the colloid increases due to the increase in temperature, and the colloid can drive the reflux to fill the gas channel, which is more conducive to reducing the appearance of gas channels of the adhesive after curing.
[0038] For the specific packaging method steps, please refer to the attached Figure 3 A deep ultraviolet LED packaging method, the method using the deep ultraviolet LED packaging structure of claim 1, comprising the following steps:
[0039] S1, using a glue dispenser to dispense glue along the glue dispensing groove 21. Preferably, the glue is dispensed in the glue dispensing groove 21 so that the surface of the glue is slightly higher than the notch of the glue dispensing groove 21.
[0040] S2, heating the deep ultraviolet LED packaging structure, and placing lens B in the assembly groove 20 to make a blank. The S2 step actually includes two small steps; S21, before placing lens B, blowing hot air downward from the top of the deep ultraviolet LED packaging structure; S22, placing lens B in the assembly groove 20, and continuing to blow hot air downward from the top of the deep ultraviolet LED packaging structure, so that the air in the solid crystal cavity 10 maintains a stable temperature. In this step, the excess glue can be allowed to flow to the overflow groove 22 through the overflow channel 23, and the lens B is glued in the glue dispensing groove 21. The excess glue overflows into the overflow groove 22, which can avoid the lens warping problem caused by the non-right-angle edge at the connection position between the bottom of the assembly groove 20 and the edge ring plate 25, which is generally caused by process problems. The whole is kept at a low temperature and lightly heated to keep the colloid in a slightly solidified state. In step S21 and step S22, the hot air temperature is kept below 100°C as much as possible, and the hot air blowing state can be maintained all the time. The main purpose of these two small steps is to heat the air in the crystal bonding chamber. Step S21 only needs to be maintained for a short time, that is, the hot air blowing state can be maintained throughout the entire process of installing and placing lens B. The hot air blowing state is still maintained for a period of time after the installation and placement of lens B is completed. For example, step S21 lasts for 30 seconds, and step S22 lasts for 30 seconds. This is only one of the feasible embodiments, and is not a limitation of this technical solution.
[0041] S3, placing the blank in S2 in an oven for baking. As a preferred embodiment, in this step, the baking temperature is still kept as close as possible to the hot air temperature in step S2, and the best temperature is that the baking temperature in step S3 is within 10°C higher than the hot air heating temperature in step S2, so that the uncured glue will not flow and form a gas escape channel due to the internal and external pressure difference during the soft baking process. As a more preferred embodiment, after covering the lens, a pressing plate with a pin is used to press the lens to prevent the lens from warping or falling off until the finished product is made.
[0042] S4, placing the blank in a high temperature oven and baking it at high temperature to make a finished product. In this step, high temperature baking, for example, baking temperature of 150°C, baking time is not less than 1 hour, and the baking time is longer than the time used in step S3. In step S3, the soft baking needs to bake the adhesive to a certain degree of basic solidification before step S4 is performed, for example, the soft baking time is more than 10 minutes and not more than 1 hour. These are just one of the feasible embodiments, and are not a limitation of this technical solution.
[0043] Embodiment 2
[0044] As a more preferred embodiment, the bottom of the glue dispensing groove 21 is lower than the bottom of the overflow groove 22. Before step S3, the blank is vacuumed. In this way, in the glue dispensing groove 21, if an air outlet channel appears at the beginning, the excess glue in the overflow groove 22 will flow back to the glue dispensing groove 21 for replenishment under the action of gravity after the gas is exhausted.
[0045] As a preferred embodiment, Figure 4 As shown, the bottom of the glue dispensing groove 21 gradually decreases from the outside to the inside, the bottom of the overflow groove 22 gradually decreases from the outside to the inside, and the bottom surface of the overflow channel 23 gradually decreases from the outside to the inside, wherein the outside to the inside refers to the outside of the bracket 2 to the center of the bracket 2, and the bottom of the glue dispensing groove 21, the bottom of the overflow groove 22 and the bottom surface of the overflow channel 23, their inclination angle is α, α is generally between 3° and 10°, so that when the air in the solid crystal cavity is heated, the expanded overflowing gas The glue basically overflows through the overflow channel 23. When the air pressure stabilizes, the overflow groove 22 is tilted inwardly due to the bottom of the groove, so that the glue therein can flow back to the overflow channel 23 smoothly, and the bottom surface of the overflow channel 23 is tilted inwardly, so that the glue therein can flow toward the glue dispensing groove 21. At the same time, the bottom of the glue dispensing groove 21 is also tilted inwardly, so that the glue in the glue dispensing groove 21, the glue in the overflow channel 23, and the glue in the overflow groove 22 can all flow toward the glue dispensing groove 21 in a fluid state.
[0046] As a further preferred embodiment, Figure 2 and Figure 5 As shown, the overflow channel 23 is located at the midpoint of the overflow groove 22, and the bottom of the overflow groove 22 gradually tilts downward from both ends to the middle, wherein the tilt angle β there is generally between 1° and 5°. Such a structure design makes it possible for the fluid glue to flow back to the overflow channel 23 no matter how the glue is distributed in the overflow groove 22.
[0047] Embodiment 3
[0048] In this embodiment, a deep ultraviolet LED packaging structure is provided, which is different from the second embodiment in that a channel is provided on the edge ring plate 25, and a slider 29 capable of sliding therein is provided in the channel, and the slider 29 can slide from the outside to the inside relative to the edge ring plate 25, and one end of the slider 29 is exposed from the outside of the edge ring plate 25, and the position of the slider 29 is aligned with the overflow channel 23. In this way, when the glue in the glue dispensing groove 21 overflows to the overflow groove 22, the slider 29 is pressed from the outside so that the slider 29 slides and squeezes the glue back into the overflow channel 23, and the pressing slider 29 can also be fixed after the subsequent glue solidification.
[0049] Embodiment 4
[0050] A deep ultraviolet LED packaging structure is provided, which is different from the first embodiment in that, in this embodiment, the bracket 2 is provided with more overflow channels 23, such as Figure 8 As shown, the specific structure includes a base 24, the upper surface of the base 24 is provided with a rectangular edge ring plate 25 and a middle convex ring 26, the convex ring 26 is rectangular and has four sides, each side is provided with three overflow channels 23, one in the middle and one near each end point.
[0051] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.
Claims
1. A deep ultraviolet LED packaging structure, characterized in that: The invention comprises a substrate (1) and a bracket (2) connected to the upper surface of the substrate (1); the bracket (2) is in a surrounding structure and forms a crystal-fixing cavity (10) in the middle so as to arrange a light-emitting element in the crystal-fixing cavity (10); the upper surface of the bracket (2) is provided with an assembly groove (20) arranged around the crystal-fixing cavity (10) and used to place a lens; the bracket (2) is provided with a glue dispensing groove (21) surrounding the crystal-fixing cavity (10) on the bottom of the assembly groove (20); the bracket (2) is also provided with an overflow groove (22) surrounding the glue dispensing groove (21) on the bottom of the assembly groove (20); and a plurality of overflow channels (23) are provided between the glue dispensing groove (21) and the overflow groove (22) to connect the two.
2. The deep ultraviolet LED packaging structure according to claim 1, characterized in that: The bracket (2) includes a base (24), the upper surface of the base (24) is provided with an edge ring plate (25) extending upward, the edge ring plate (25) and the base (24) enclose the assembly groove (20), the upper surface of the base (24) is also provided with a middle convex ring (26) located on the inner side of the edge ring plate (25), and an inner ring convex ring (27) located on the inner side of the middle convex ring (26), the middle convex ring (26) and the inner ring convex ring (27) form the glue dispensing groove (21), the middle convex ring (26) and the edge ring plate (25) form the overflow groove (22), and the middle convex ring (26) is provided with a plurality of notches to form the overflow channel (23).
3. The deep ultraviolet LED packaging structure according to claim 2, characterized in that: The height of the middle convex ring (26) is less than or equal to the height of the inner convex ring (27).
4. The deep ultraviolet LED packaging structure according to claim 2, characterized in that: The bottom of the glue dispensing groove (21) is lower than the bottom of the overflow groove (22).
5. A deep ultraviolet LED packaging method, the method using a deep ultraviolet LED packaging structure according to claim 1, characterized in that: The following steps are involved: S1, using a glue dispensing machine to dispense glue along the glue dispensing groove (21); S2, heating the deep ultraviolet LED packaging structure, and placing a lens in the assembly groove (20) to form a blank; S3, placing the blank in step S2 in an oven for baking; S4, placing the blank in a high temperature oven and baking it at high temperature to make a finished product.
6. The deep ultraviolet LED packaging method according to claim 5, characterized in that: The step S2 comprises the following sub-steps: S21, before placing the lens, blowing hot air downward from above the deep ultraviolet LED packaging structure, thereby heating the air in the crystal bonding cavity (10); S22, placing a lens in the assembly groove (20), and continuing to blow hot air downward from above the deep ultraviolet LED packaging structure, thereby continuously heating the deep ultraviolet LED packaging structure, so that the air temperature in the crystal bonding cavity (10) remains stable.
7. The deep ultraviolet LED packaging method according to claim 6, characterized in that: In both step S21 and step S22, the hot air temperature is maintained below 100°C.
8. The deep ultraviolet LED packaging method according to claim 4, characterized in that: The bottom of the glue dispensing groove (21) is lower than the bottom of the overflow groove (22). Before step S3, the blank is subjected to a vacuum treatment.
9. The deep ultraviolet LED packaging method according to claim 6, characterized in that: The baking temperature in step S3 is T1, and the hot air heating temperature in step S2 is T2, then T1-T2≤10°C.
10. The deep ultraviolet LED packaging method according to claim 5, characterized in that: The bottom of the dispensing groove (21) gradually decreases from the outside to the inside, the bottom of the overflow groove (22) gradually decreases from the outside to the inside, and the bottom surface of the overflow channel (23) gradually decreases from the outside to the inside.