LED packaging structure

Abstract

The utility model relates to the technical field of LED packaging, in particular to an LED packaging structure, which comprises a first electrode, an LED wafer fixed on the first electrode, the LED wafer is electrically connected with a second electrode through a gold wire, the first electrode and the second electrode are attached to a packaging body, an exhaust channel is arranged on the packaging body, and the exhaust channel is communicated with the first electrode and the second electrode. At least part of the exhaust channel is communicated to the position of the face where the LED wafer is installed on the first electrode, internal water vapor is guided to be exhausted in the packaging process, the possibility of water vapor accumulation is further reduced, internal stress is reduced, layering and cracking between the light-transmitting layer and the first electrode and between the light-transmitting layer and the second electrode are prevented, and the service life of the LED wafer is prolonged. The problem that the reliability of the LED module is affected by damp easily in the reflow soldering process is solved, the service life of the LED module is prolonged, and the use stability of the LED module is improved.

Description

Technical Field

[0001] This utility model relates to the field of LED packaging technology, and in particular to an LED packaging structure. Background Technology

[0002] In current LED packaging production, due to limitations in processes and design, gaps are commonly formed between the bottom of the chip and the packaging substrate or support structure. From a process perspective, it is difficult to ensure an absolutely tight fit between the chip and the support structure during processes such as die bonding and soldering. For example, during die bonding, the uniformity of the silver paste thickness and curing shrinkage can both lead to tiny gaps between the chip and the substrate. From a design perspective, to meet heat dissipation requirements, some packaging designs intentionally reserve heat dissipation channels on the bottom of the chip, inevitably creating gaps. These gaps accumulate moisture during LED operation.

[0003] When LEDs are in a high-humidity environment, water molecules can diffuse or capillary into the gaps at the bottom of the chip through the micropores of the encapsulation material or the gaps in the encapsulation structure. In the subsequent reflow process, to solder the chip to the external circuitry, the LED needs to be heated to a high temperature of 180℃-260℃. At this temperature, the moisture accumulated in the gaps will rapidly vaporize, expanding instantly and generating strong water vapor expansion pressure. This pressure directly affects critical components such as the interface between the chip and the encapsulation material, the solder joints, and the encapsulation shell. Under the influence of water vapor expansion pressure, the LED encapsulation structure is highly susceptible to delamination. Interface delamination disrupts the chemical bond between the LED chip and the encapsulation material, leading to interruptions in the LED's electrical connection and heat conduction path. Poor soldering results in unstable electrical connections between the LED chip and the external circuitry. This not only reduces the LED's brightness and stability but can also cause localized overheating, accelerate solder joint aging and failure, further affecting the LED's performance and reliability. In summary, existing LED packaging structures have significant shortcomings in handling the gaps at the bottom of the chip, making LEDs susceptible to moisture during reflow, leading to a series of reliability issues. Utility Model Content

[0004] The purpose of this utility model is to provide an LED packaging structure that addresses the aforementioned technical problems, such as the susceptibility of LEDs to moisture during reflow soldering, which affects the reliability of LED modules and improves their lifespan and stability.

[0005] The technical problem solved by this utility model is addressed by the following technical solution: an LED packaging structure, comprising:

[0006] First electrode;

[0007] LED chip, the LED chip being fixed on the first electrode;

[0008] The second electrode is electrically connected to the LED chip via a gold wire.

[0009] The package body, wherein the first electrode and the second electrode are attached to and mounted in contact with the package body;

[0010] The package body has an exhaust channel, and at least a portion of the exhaust channel is connected to the surface where the LED chip is mounted on the first electrode.

[0011] This utility model also has the following technical features:

[0012] In one embodiment of this utility model, the exhaust channel is hole-shaped, with one end of the exhaust channel located on the surface of the first electrode away from where the LED chip is mounted, and the other end of the exhaust channel located at the bottom of the package.

[0013] In one embodiment of the present invention, the exhaust channel is in the form of a strip-shaped opening, and the exhaust channel is arranged along the width direction of the package.

[0014] In one embodiment of this utility model, there is a gap between one end of the first electrode and the package body, the gap is connected to the exhaust channel, and the LED chip is located near the gap.

[0015] In one embodiment of this utility model, the surface on which the LED chip is mounted on the first electrode is provided with a plurality of air guide openings, and the air guide openings are connected to the exhaust channel.

[0016] In one embodiment of the present invention, a fitting protrusion is provided on the surface where the first electrode is mounted on the LED chip.

[0017] In one embodiment of the present invention, a groove is provided on the first electrode, and the LED chip is placed in the groove.

[0018] In one embodiment of the present invention, a boss is provided on the first electrode, and a slot is provided in the boss, and the LED chip is inserted into the slot.

[0019] In one embodiment of the present invention, the bottom of the groove is provided with a connecting hole, which is connected to the exhaust channel.

[0020] In one embodiment of this utility model, the bottom of the slot is provided with an air guide hole, which is connected to the exhaust channel.

[0021] Compared with existing technologies, the beneficial effects of this utility model are reflected in the following aspects: In the structural design, the first electrode is welded and fixed to the LED chip, and the two are closely attached, minimizing the generation of gaps at the bottom of the chip; The existence of the exhaust channel can not only dissipate heat, but also guide the internal moisture to be discharged during the packaging process, further reducing the possibility of moisture accumulation; Compared with traditional packaging, it prevents moisture accumulation at the bottom of the chip from the source, reducing the risk of packaging failure caused by moisture.

[0022] The package is fitted and mounted to the first and second electrodes, ensuring good sealing. This tight fit effectively prevents water molecules from entering the package through micropores or gaps, preventing interface delamination caused by moisture expansion at high reflow temperatures, maintaining the stability of the chemical bond between the LED chip and the package material, and ensuring unobstructed electrical connections and heat conduction paths.

[0023] Thanks to the reliable packaging structure, soldering problems caused by moisture are avoided. During the reflow process, stable electrical connections are ensured, and signal transmission between the LED chip and the external circuit is stable. Problems such as reduced brightness and decreased stability caused by solder joint aging and failure will not occur, thus extending the lifespan of the LED and improving product quality. Attached Figure Description

[0024] Figure 1 and Figure 2 These are schematic diagrams of the LED module from two different perspectives in one embodiment of this utility model;

[0025] Figure 3 This is a front view of an LED module in one embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the LED module in another embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the LED module in another embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the structure of the first electrode, the second electrode, the LED chip, and the gold wire in an LED module according to one embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram of the first electrode structure in an LED module according to one embodiment of the present invention;

[0030] Figure 8 This is a schematic diagram of the first electrode structure in the LED module in another embodiment of the present invention;

[0031] Figure 9This is a schematic diagram of the first electrode structure in the LED module in another embodiment of the present invention;

[0032] Figure 10 This is a schematic diagram of the first electrode structure in the LED module in other embodiments of the present invention;

[0033] Figure 11 This is a schematic diagram of the end face of the first electrode in the LED module in another embodiment of the present invention;

[0034] Explanation of icon numbers:

[0035] 10. One electrode; 11. Groove; 111. Connecting hole; 12. Boss; 121. Slot; 1211. Air vent; 13. Fitting protrusion;

[0036] 20. LED chips;

[0037] 30. Second electrode;

[0038] 40. Gold thread;

[0039] 50. Encapsulation body; 51. Exhaust channel; 52. Window; 53. Light-transmitting layer; 54. Light-transmitting part. Detailed Implementation

[0040] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0041] The illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show the components related to this utility model and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0042] When LEDs are in a high-humidity environment, water molecules can diffuse or capillary into the gaps at the bottom of the chip through the micropores of the encapsulation material or the gaps in the encapsulation structure. In the subsequent reflow process, to solder the chip to the external circuitry, the LED needs to be heated to a high temperature of 180℃-260℃. At this temperature, the moisture accumulated in the gaps will rapidly vaporize, expanding instantly and generating strong water vapor expansion pressure. This pressure directly affects critical components such as the interface between the chip and the encapsulation material, the solder joints, and the encapsulation shell. Under the influence of water vapor expansion pressure, the LED encapsulation structure is highly susceptible to delamination. Interface delamination disrupts the chemical bond between the LED chip and the encapsulation material, leading to interruptions in the LED's electrical connection and heat conduction path. Poor soldering can result in unstable electrical connections between the LED chip and the external circuitry. This not only reduces the brightness and stability of the LED, but may also lead to localized overheating, accelerate the aging and failure of solder joints, and further affect the performance and reliability of the LED. To address this, an LED packaging structure is proposed, comprising: a first electrode 10; an LED chip 20 fixed on the first electrode 10; a second electrode 30, wherein the LED chip 20 is electrically connected to the second electrode 30 via a gold wire 40; and a package 50, wherein the first electrode 10 and the second electrode 30 are fitted and mounted to the package 50; wherein the package 50 has an exhaust channel 51, and at least a portion of the exhaust channel 51 is connected to the surface of the first electrode 10 where the LED chip 20 is mounted.

[0043] In one embodiment, both the first electrode 10 and the second electrode 30 present Figure 5 In the structure, the LED chip 20 is soldered and fixed to one side of the first electrode 10, see reference. Figure 2 Furthermore, a portion of this side is located within the window 52 area of ​​the package 50.

[0044] In one embodiment, see Figure 2 and Figure 3 Taking a white-shell LED as an example, the package 50 is a white-shell package. A window 52 is opened on the package 50, the LED chip 20 is located in the area where the window 52 is located, and the window 52 is filled with a light-transmitting layer 53.

[0045] In the above embodiment, after the two ends of the gold wire 40 are fixed, the window 52 is filled with light-transmitting resin. After the resin is cured, a light-transmitting layer 53 is formed. The exhaust channel 51 is connected to the surface where the first electrode 10 with the LED chip 20 is installed in at least a part of the area. During the encapsulation process, the internal moisture is guided to be discharged, which further reduces the possibility of moisture accumulation, thereby reducing internal stress and preventing delamination and cracking between the light-transmitting layer 53 and the first electrode 10 and the second electrode 30.

[0046] In another embodiment, see Figure 5 Taking a non-white LED as an example, the package 50 is made of BT resin substrate material. A light-transmitting part 54 is formed on the outside of the first electrode 10 and the second electrode 30. In the above embodiment, after the two ends of the gold wire 40 are fixed, a light-transmitting part 54 is formed on the outside of the first electrode 10 and the second electrode 30. After the resin is cured, the light-transmitting part 54 is formed. The exhaust channel 51 is connected to the surface where the first electrode 10 is mounted with the LED chip 20 in at least a part area. During the packaging process, it guides the internal moisture to be discharged, further reducing the possibility of moisture accumulation, thereby reducing internal stress and preventing delamination and cracking between the light-transmitting layer 53 and the first electrode 10 and the second electrode 30.

[0047] In one embodiment, see Figure 1 and Figure 3 The exhaust channel 51 is perforated. One end of the exhaust channel 51 is located on the side of the first electrode 10 opposite to the surface where the LED chip 20 is mounted, and the other end of the exhaust channel 51 is located at the bottom of the package 50.

[0048] In one embodiment, during the encapsulation process, the temperature is highest at the location of the first electrode 10 away from where the LED chip 20 is mounted. The orifice of the exhaust channel 51 is located at this location, which can quickly guide the discharge of heat and moisture.

[0049] In one embodiment, the exhaust channel 51 is not limited to a round hole, a square hole, or other irregularly shaped holes.

[0050] In another embodiment, see Figure 4 The exhaust channel 51 is in the shape of a strip opening and is arranged along the width direction of the package 50.

[0051] In one embodiment, the strip-shaped open exhaust channel 51 can be arranged through the width of the package 50, or it can be arranged without penetrating. It is necessary to ensure that the moisture in the gap between the first electrode 10 and the light-transmitting layer 53 can be quickly discharged during the reflow process, thereby avoiding delamination of the LED package structure, which would cause delamination between the LED chip 20 and the first electrode 10, resulting in a reduction in the lifespan of the LED module.

[0052] In one embodiment, see Figure 3 To ensure that moisture can be discharged from the surface where the LED chip 20 is mounted on the first electrode 10 to the exhaust channel 51, there is a gap between one end of the first electrode 10 and the package 50, as shown by the arrow in the figure. The gap is connected to the exhaust channel 51, and the LED chip 20 is located near the gap.

[0053] In another embodiment, see Figure 6 The first electrode 10 has multiple air duct openings on the surface where the LED chip 20 is mounted, and the air duct openings are connected to the exhaust channel 51.

[0054] In one embodiment, the air duct opening is an opening located on the surface where the LED chip 20 is mounted on the first electrode 10, thereby enabling the surface where the LED chip 20 is mounted on the first electrode 10 to be connected to the outside through the exhaust channel 51, and realizing the rapid removal of water vapor.

[0055] In one embodiment, see Figure 9 and Figure 11 To further prevent delamination between the cured light-transmitting layer 53 and the LED chip 20 and the first electrode 10, an interlocking protrusion 13 is provided on the surface of the first electrode 10 where the LED chip 20 is mounted.

[0056] In one embodiment, see Figure 9 The fitting protrusion 13 is arranged along the width direction of the first electrode 10, and its cross-section can be rectangular or other shapes, see reference. Figure 10 Preferably, it is a large semi-circle with a larger top and a smaller bottom, which can ensure that the light-transmitting layer 53 and the LED chip 20 are reliably integrated with the first electrode 10, avoiding delamination problems caused by moisture during reflow soldering.

[0057] In one embodiment, in order to fix the LED chip 20 and further reduce the delamination and displacement problem between the LED chip 20 and the first electrode 10, a groove 11 is provided on the first electrode 10, and the LED chip 20 is held in the groove 11.

[0058] In one embodiment, see Figure 7 The cross-section of the groove 11 can be rectangular or circular. When the LED chip 20 is fixed in the groove 11 by conductive silver paste, the welding area between the LED chip 20 and the first electrode 10 can be increased.

[0059] In another embodiment, see Figure 10 The first electrode 10 is used to fix the LED chip 20 in a flat position, and the LED chip 20 is fixed in the flat position of the first electrode 10 by conductive silver paste.

[0060] In one embodiment, to reduce moisture problems between the LED chip 20 and the first electrode 10, a connecting hole 111 is provided at the bottom of the groove 11, and the connecting hole 111 is connected to the exhaust channel 51.

[0061] In another embodiment, see Figure 8To reduce the impact on the light emission of the LED chip 20, a boss 12 is provided on the first electrode 10, and a slot 121 is provided in the boss 12, and the LED chip 20 is placed in the slot 121.

[0062] Similarly, the cross-section of the slot 121 is rectangular or circular. When the LED chip 20 is fixed in the groove 11 by conductive silver paste, the welding area between the LED chip 20 and the first electrode 10 can be increased.

[0063] In one embodiment, an air guide hole 1211 is provided at the bottom of the slot 121, and the air guide hole 1211 is connected to the exhaust channel 51.

[0064] The bottom space of the LED chip 20 is connected to the exhaust channel 51 through the connecting hole 111 and the vent hole 1211, which prevents moisture from accumulating in the gap at the bottom of the chip. Even in a high humidity environment, a small amount of moisture that enters the packaging structure can be discharged through this channel, effectively preventing LED performance degradation caused by moisture accumulation, such as interface delamination and poor soldering, and extending the life of the LED.

[0065] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0066] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An LED packaging structure, characterized in that, include: First electrode (10); LED chip (20), the LED chip (20) is fixed on the first electrode (10); The second electrode (30) is electrically connected to the LED chip (20) via a gold wire (40); The package (50) is fitted with the first electrode (10) and the second electrode (30); The package (50) has an exhaust channel (51) which is at least partially connected to the surface where the first electrode (10) is mounted on the LED chip (20).

2. The LED packaging structure according to claim 1, characterized in that: The exhaust channel (51) is perforated. One end of the exhaust channel (51) is located on the side of the first electrode (10) away from the surface where the LED chip (20) is mounted. The other end of the exhaust channel (51) is located at the bottom of the package (50).

3. The LED packaging structure according to claim 1, characterized in that: The exhaust channel (51) is in the shape of a strip opening and is arranged along the width direction of the package (50).

4. The LED packaging structure according to claim 1, characterized in that: There is a gap between one end of the first electrode (10) and the package (50), the gap is connected to the exhaust channel (51), and the LED chip (20) is located near the gap.

5. The LED packaging structure according to claim 1, characterized in that: The first electrode (10) has multiple air guide openings on the surface where the LED chip (20) is mounted, and the air guide openings are connected to the exhaust channel (51).

6. The LED packaging structure according to claim 1, characterized in that: The first electrode (10) has a fitting protrusion (13) on the surface where the LED chip (20) is mounted.

7. The LED packaging structure according to claim 1, characterized in that: The first electrode (10) is provided with a groove (11), and the LED chip (20) is placed in the groove (11).

8. The LED packaging structure according to claim 1, characterized in that: The first electrode (10) is provided with a boss (12), and a slot (121) is provided in the boss (12), and the LED chip (20) is placed in the slot (121).

9. The LED packaging structure according to claim 7, characterized in that: The bottom of the groove (11) is provided with a connecting hole (111), which is connected to the exhaust channel (51).

10. The LED packaging structure according to claim 8, characterized in that: The bottom of the slot (121) is provided with an air guide hole (1211), which is connected to the exhaust channel (51).

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