High-airtightness LED lamp bead structure and preparation method thereof

Abstract

The invention discloses a high-airtightness LED lamp bead structure and a preparation method thereof.The LED lamp bead structure comprises a light-emitting chip and a lamp bead support used for fixedly installing the light-emitting chip, a metal pin comprises a connecting section and a welding section, the connecting section is continuously bent downwards twice from a metal substrate and then connected with the welding section, and the welding section is connected with the light-emitting chip. The connecting section comprises a first connecting section, a second connecting section and a third connecting section which are sequentially connected between the metal substrate and the welding section; the metal substrate is located in the inner cavity of the reflection cup, and the lower surface of the metal substrate is not lower than the bottom surface of the reflection cup, so that at least part of the first connection section is located in the inner cavity of the reflection cup; and the ratio of the vertical height of the first connecting section to the cup depth of the reflecting cup is (1.05-1.34): 1. By implementing the LED lamp bead, the brightness and the air tightness of the lamp bead can be improved, the use of packaging glue is reduced, the cost is reduced, meanwhile, the difficulty of the manufacturing process of the LED lamp bead is reduced, and the quality of the LED lamp bead is improved.

Description

Technical Field

[0001] The invention relates to the technical field of light emitting diodes, and in particular to a highly airtight LED lamp bead structure and a preparation method thereof. Background Art

[0002] With the widespread application of display technology, the application scenarios are also diversified. Among them, the development trend of RGB display movie screens shows rapid growth and continuous technological advancement. It is expected that there will be more applications and market share in the future. The development of RGB display movie screens has benefited from the continuous advancement and innovation of technology, especially in LED display technology, and its application is rapidly expanding in the film and television market. LED movie screens have technical advantages such as high brightness, ultra-high contrast, and good color consistency, which enables them to completely replace traditional projectors and provide the industry and audiences with a variety of projection technologies and product choices. Among them, the application of LED display devices, which are key components of display screens, has also become more important, especially the development of display screens towards high viewing angles, high brightness, and high reliability, which puts higher requirements on LED display devices, that is, higher viewing angles, higher brightness, higher reliability, and higher airtightness are required for lamp beads, making their application in outdoor scenes more in line with the requirements.

[0003] See also Figure 1 and Figure 2 The existing TOP LED device uses a TOP stamping injection molding bracket as a bracket. The bracket is divided into two sides, the front side is a functional area composed of plastic and metal parts after stamping and stretching. The plastic part is formed by injection molding to form a reflector cup 300 to protect the functional area. The back side is composed of plastic and metal pins 220. The metal pins 220 are pins formed after bending. Among them, the front functional area uses silver glue or insulating glue to fix the light-emitting chip 100 in the functional area, and the bonding wire 600 is welded to the chip electrode and the functional area to form an electrical connection between the light-emitting chip 100 and the functional area. Finally, the bracket is sealed with glue through a dispensing process, and then blanked into regular lamp beads that can emit RGB three primary colors.

[0004] However, the existing lamp bead structure has the following defects: (1) The bottom of the reflective cup 300 is on the same plane as the light-emitting chip 100. The depth of the reflective cup 300 is too high, so the light of the light-emitting chip 100 cannot be dispersed, resulting in a large loss of brightness of the light-emitting chip 100; (2) Since the light-emitting chip 100 emits light on five sides after solidification, the bottom is on the same plane, resulting in a loss of brightness of the light-emitting chip 100; (3) The stretched height is relatively short. In a high-humidity environment, water vapor is more likely to penetrate into the interior of the lamp bead along the exposed metal parts. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a highly airtight LED lamp bead structure and a preparation method thereof, and by redesigning the LED lamp bead structure, the brightness and airtightness of the lamp bead are improved, the use of packaging glue is reduced, the cost of the LED lamp bead structure is reduced, and the difficulty of the LED lamp bead manufacturing process is reduced, thereby improving the quality of the LED lamp bead.

[0006] In order to solve the above technical problems, the first aspect of the present invention provides a highly airtight LED lamp bead structure, comprising: a light-emitting chip, and a lamp bead bracket for fixing and installing the light-emitting chip;

[0007] The lamp bead bracket includes a metal bracket and a reflective cup wrapping the metal bracket, wherein the metal bracket includes a metal substrate for fixing and mounting the light-emitting chip, and a metal pin connected to the substrate;

[0008] The metal pin includes a connecting section and a welding section, the connecting section is connected to the welding section after being bent downward from the metal substrate twice continuously, and the connecting section includes a first connecting section, a second connecting section and a third connecting section which are sequentially connected between the metal substrate and the welding section;

[0009] The metal substrate is located in the inner cavity of the reflector cup, and the lower surface of the metal substrate is not lower than the bottom surface of the reflector cup, so that at least part of the first connecting section is located in the inner cavity of the reflector cup;

[0010] The ratio of the vertical height of the first connecting section to the cup depth of the reflective cup is (1.05-1.34):1.

[0011] As an improvement of the above solution, the first connecting section and the bottom of the reflective cup form an angle, and the angle is less than 90°.

[0012] As an improvement of the above solution, the angle is 75° to 85°.

[0013] As an improvement of the above solution, the first connecting section and the inner wall of the reflective cup form a groove.

[0014] As an improvement of the above solution, the vertical height between the upper surface of the metal substrate and the bottom surface of the reflective cup is 2.5% to 10% of the cup depth of the reflective cup.

[0015] As an improvement of the above solution, the length of the second connecting section is 15% to 25% of the outer diameter of the reflective cup.

[0016] As an improvement of the above solution, the metal substrate, the connecting section and the welding section are integrally formed, and the third connecting section is an I-shaped structure, so that the side surface of the metal pin is I-shaped.

[0017] As an improvement of the above solution, the reflective cup is formed by stamping and injection molding of a plastic material, and the reflective cup is a bowl-cup structure with a circular cup mouth;

[0018] The interior of the reflective cup is filled with packaging glue for sealing and protecting the light-emitting chip.

[0019] As an improvement of the above solution, the front and / or back of the reflective cup is provided with an identification structure for locating and identifying the polarity of the LED lamp beads;

[0020] Two ends of the light emitting chip are connected to the metal bracket through bonding wires and are fixed to the PCB board through the welding section.

[0021] The second aspect of the present invention further provides a method for preparing the highly airtight LED lamp bead structure, comprising:

[0022] (1) providing a metal plate and processing it to form a preliminary shape of a metal bracket;

[0023] (2) injection molding to obtain a reflective cup, and wrapping the metal substrate in (1) therein, with the lower surface of the metal substrate being not lower than the bottom surface of the reflective cup, and then cooling and solidifying to obtain a semi-finished lamp bead bracket;

[0024] (3) processing the semi-finished lamp bead bracket obtained in (2) to bend the metal pins into shape to obtain a finished lamp bead bracket;

[0025] (4) Fixing the light-emitting chip on the metal substrate and electrically connecting the light-emitting chip and the metal substrate;

[0026] (5) Fill the reflector cup with sealant, bake and solidify it to complete the packaging.

[0027] The implementation of the present invention has the following beneficial effects:

[0028] (1) In the present invention, based on the original metal bracket structure, the position of the functional area is adjusted so that the height of the functional area is not lower than the bottom of the reflective cup, and at least part of the first connecting section is located in the inner cavity of the reflective cup, thereby shortening the propagation path of the light emitted by the light-emitting chip, allowing more light to be reflected by the inner wall of the reflective cup, optimizing the beam distribution and improving the light extraction efficiency, thereby increasing the chip brightness of the LED lamp bead;

[0029] (2) In the present invention, the position of the functional area is adjusted so that the height of the functional area is not lower than the bottom of the reflective cup. At least part of the first connecting section is located in the inner cavity of the reflective cup, so that a certain height difference is formed between the light emitting chip and the bottom of the reflective cup. Part of the light emitted from the bottom of the light emitting chip can also be reflected by the bottom and form emitted light, further increasing the light emitting brightness of the light emitting chip, avoiding the restriction on light emission when the bottom of the reflective cup and the light emitting chip are in the same plane, and reducing the brightness loss of the light emitting chip at the bottom of the reflective cup.

[0030] (3) In the present invention, the position of the functional area in the reflector cup is raised so that at least part of the first connecting section is located in the inner cavity of the reflector cup, thereby extending the penetration path of water vapor into the interior of the LED lamp bead, thereby increasing the airtightness of the LED lamp bead structure, reducing the amount of packaging glue used, and reducing costs;

[0031] (4) In the present invention, the ratio of the vertical height of the first connecting section to the cup depth of the reflective cup is limited, which not only significantly improves the airtightness of the LED lamp bead structure, but also maintains a good supporting effect on the LED lamp bead. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 : A schematic diagram of a top view of an LED lamp bead structure in the prior art;

[0033] Figure 2 : A schematic diagram of the structure of the side of an LED lamp bead structure in the prior art;

[0034] Figure 3 : A schematic diagram of the top view of the LED lamp bead structure in the present invention;

[0035] Figure 4 : A schematic diagram of the side structure of the LED lamp bead structure in the present invention;

[0036] Figure 5 : Figure 4 A partial enlarged view of the middle A area;

[0037] Figure 6 : A schematic diagram of the structure of the side surface of the metal pin in the present invention;

[0038] Figure 7 : A schematic diagram of the structure of the side of a metal pin in the prior art;

[0039] Figure 8 : A schematic diagram of the structure of the back side of the LED lamp bead structure in the prior art;

[0040] Fig. 9 : A schematic structural diagram of the back side of the LED lamp bead structure in the present invention.

[0041] Reference numerals:

[0042] 100-light-emitting chip; 200-metal bracket; 210-metal substrate; 220-metal pin; 221-connecting section; 222-welding section; 223-first connecting section; 224-second connecting section; 225-third connecting section; 300-reflection cup; 400-packaging glue; 500-soldering glue; 600-bonding wire; 700-identification structure. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail with specific embodiments below.

[0044] In order to solve the above problems, the first aspect of the present invention provides a highly airtight LED lamp bead structure, see Figure 3 and Figure 4 , comprising: a light emitting chip 100, and a lamp bead bracket for fixing and installing the light emitting chip 100;

[0045] The lamp bead bracket includes a metal bracket 200 and a reflective cup 300 wrapping the metal bracket 200, wherein the metal bracket 200 includes a metal substrate 210 for fixing and mounting the light emitting chip 100, and a metal pin 220 connected to the substrate;

[0046] The metal pin 220 includes a connecting section 221 and a welding section 222. The connecting section 221 is bent downward from the metal substrate 210 twice and connected to the welding section 222. The connecting section 221 includes a first connecting section 223, a second connecting section 224 and a third connecting section 225 which are sequentially connected between the metal substrate 210 and the welding section 222.

[0047] The metal substrate 210 is located in the inner cavity of the reflector cup 300 , and the lower surface of the metal substrate 210 is not lower than the bottom surface of the reflector cup 300 , so that at least part of the first connecting section 223 is located in the inner cavity of the reflector cup 300 .

[0048] In the present invention, based on the original structure of the metal bracket 200, the position of the functional area is adjusted so that the height of the functional area is not lower than the bottom of the reflective cup 300, and at least part of the first connecting section 223 is located in the inner cavity of the reflective cup 300. On the one hand, the propagation path of the light emitted by the light-emitting chip 100 is shortened, so that more light can be reflected by the inner wall of the reflective cup 300, the light beam distribution is optimized and the light extraction efficiency is improved, thereby increasing the chip brightness of the LED lamp bead. On the other hand, a certain height difference is formed between the bottom of the light-emitting chip 100 and the reflective cup 300, and part of the light emitted from the bottom of the light-emitting chip 100 can also be reflected by the bottom and form an outgoing light, further increasing the light brightness of the light-emitting chip 100, avoiding the restriction on the light emission when the bottom of the reflective cup 300 and the light-emitting chip 100 are in the same plane, and reducing the brightness loss of the light-emitting chip 100 at the bottom of the reflective cup 300. In addition, the position of the functional area in the reflective cup 300 is improved so that at least part of the first connecting section 223 is located in the inner cavity of the reflective cup 300, which extends the penetration path of water vapor into the interior of the LED lamp bead, thereby increasing the airtightness of the LED lamp bead structure, reducing the use of the packaging glue 400, and reducing costs.

[0049] Preferably, see Figure 5 , the cup depth of the reflective cup 300 is H1, and the vertical height H2 between the upper surface of the metal substrate 210 and the bottom surface of the reflective cup 300 is 2.5% to 10% of the cup depth H1 of the reflective cup 300. If the H2 value is too large, part of the light will be totally reflected and cannot be smoothly emitted, thereby reducing the light efficiency and energy utilization rate, and may also affect the collimation of the light beam, thereby affecting the uniformity and clarity of the display screen, especially when there is sufficient outdoor light, the uniformity and clarity of the display screen are required to be higher. Exemplarily, H2 is 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10% of H1, etc. In some specific and preferred embodiments, the vertical height H2 between the upper surface of the metal substrate 210 and the bottom surface of the reflective cup 300 is ≥ 200 μm; more preferably, 200 μm ≤ H2 ≤ 700 μm. In some specific and preferred embodiments, H1 is 0.7 mm.

[0050] In the traditional lamp bead structure, the stretching height of the metal pin 220 is generally within 0.7mm to 0.9mm. The stretching height is relatively short, and water vapor is more likely to penetrate into the interior of the lamp bead through the metal parts. In addition, the thickness of the plastic on the outside of the metal parts and the lamp bead is relatively thin. When the bracket is manufactured and formed, the pin part needs to be bent and formed under the action of external force. Under the lever theorem, the internal metal parts and the plastic part are prone to form gaps, which will further reduce the air tightness of the LED lamp bead. In the present invention, on the basis of adjusting the height of the functional area, the stretching height of the LED lamp bead structure is increased, that is, the vertical height of the first connecting section 223 is increased, and the penetration path of water vapor into the interior of the lamp bead is further extended, thereby increasing the air tightness of the LED lamp bead structure.

[0051] Preferably, the ratio of the vertical height H3 of the first connecting section 223 to the cup depth H1 of the reflective cup 300 is (1.05-1.34):1, so that the stretched height is increased by 300μm-400μm compared with the traditional LED lamp bead structure, which not only has a significant improvement on the airtightness of the LED lamp bead structure, but also can still maintain a good support effect on the LED lamp bead. If the length of the first connecting section 223 is too long, its resistance will increase, thereby generating more heat, which will reduce the energy efficiency and life of the LED lamp bead. The ratio of the vertical height of the first connecting section 223 to the cup depth of the reflective cup 300 is exemplarily 1.05:1, 1.1:1, 1.15:1, 1.2:1, 1.25:1, 1.3:1, 1.34:1, etc.

[0052] Further, the first connecting section 223 forms an angle θ with the bottom of the reflector cup 300, and the angle θ is less than 90°, so that the first connecting section 223 is non-vertically set, starting from the two ends of the metal substrate 210, maintaining a certain inclination angle through the reflector cup 300 and continuing to extend downward, extending the penetration path of water vapor into the interior of the LED lamp bead as much as possible. More preferably, the angle θ is 75° to 85°. Under the appropriate stretching height, not only can the length of the first connecting section 223 be maintained to meet the requirements of the bracket, but more importantly, the length of the second connecting section 224 is increased, which can reduce the influence of the stress generated by the metal pin 220 when it is bent to form the second connecting section 224 and the third connecting section 225 on the airtightness between the plastic and the metal parts. In some specific and preferred sushi methods, the length of the second connecting section 224 is 15% to 25% of the outer diameter of the reflector cup 300, and the second connecting section 224 is horizontally set. It should be noted that the horizontal setting here includes the case where the inclination angle is less than 10°.

[0053] It is understandable that, during the crystal bonding operation of the light emitting chip 100, the crystal bonding glue 500 has the problem of varying sizes, which can easily cause the crystal bonding glue 500 to hit the inner wall of the reflective cup 300. If the crystal bonding glue 500 of the LED light emitting chip 100 hits the inside of the reflective cup 300 during the crystal bonding operation, the crystal bonding glue 500 will creep along the inner wall of the reflective cup 300, thereby causing the lamp bead to fail. Therefore, the first connecting section 223 forms an angle with the bottom of the reflective cup 300, and the first connecting section 223 and the inner wall of the reflective cup 300 form a groove, so that the functional area of ​​the lamp bead exists in the reflective cup 300 in the form of an island. When the light emitting chip 100 is crystal bonded and wire bonded, it is less restricted by the inner wall of the reflective cup 300, and it is not easy for the crystal bonding wire porcelain nozzle and the suction nozzle to hit the inner wall of the reflective cup 300, thereby reducing the creeping phenomenon of the crystal bonding glue 500 and avoiding the existence of invisible hidden dangers. The material of the bonding adhesive 500 has multiple choices, such as a layer of silver-based conductive bonding adhesive 500, an insulating bonding adhesive 500, an epoxy bonding adhesive 500, an organic silicon bonding adhesive 500, etc. In some embodiments, the bottom edge of the reflective cup 300 contacts the first connecting section 223, so that a surface of the first connecting section 223 and the inner wall of the reflective cup 300 form a groove; in other embodiments, there is a gap between the bottom edge of the reflective cup 300 and the first connecting section 223, so that the first connecting section 223, the inner wall of the reflective cup 300 and the bottom therebetween form a groove.

[0054] Optionally, the reflector cup 300 is a bowl-cup structure with a circular cup mouth, so that the reflector cup 300 has a concave structure, which is conducive to changing the light transmission angle, reducing the light loss at the bottom of the LED lamp bead when the LED lamp bead is lit, and thus improving the brightness of the LED lamp bead. Of course, the cup mouth of the reflector cup 300 can also be other shapes such as square, rounded rectangle, etc. The reflector cup 300 is formed by stamping and injection molding of a plastic material, and the plastic material has multiple choices, including but not limited to polyphthalamide (PPA), poly 1,4-cyclohexanedimethanol terephthalate (PCT), epoxy molding compound (EMC), and sheet molding compound (SMC). The interior of the reflector cup 300 is filled with a sealing glue 400 for sealing and protecting the light-emitting chip 100, so that the groove is also filled with sealing glue. The bonding force between the plastic material and the metal pin 220 is weaker than the bonding force between the sealing glue 400 and the metal pin 220, thereby playing a role in blocking water vapor. In the traditional technology, the client mounts the LED lamp bead on the PCB board and then fills the sealing glue 400 at the pin, which easily leads to water vapor infiltration. At the same time, the light-emitting chip 100 is encapsulated with a sealing glue to protect the light-emitting chip 100 from moisture, dust, chemicals, etc. in the external environment. At the same time, the electrodes and leads in the light-emitting chip 100 are sealed and covered to ensure the reliability of the electrical connection, thereby extending the service life of the LED lamp bead. The sealing glue 400 has multiple options, including but not limited to epoxy resin, silicone resin, and silica gel, and the diffusion powder or phosphor composed of silicon dioxide and silica can also be added to the body of the sealing glue 400. The composition of the phosphor can be nitride, silicate, potassium chromium, lutetium chromium, etc.

[0055] Furthermore, the metal substrate 210, the connecting section 221 and the welding section 222 are integrally formed, and the third connecting section 225 is an I-shaped structure, so that the side of the metal pin 220 is an I-shaped structure, see Figure 6 In the conventional LED lamp bead structure, the width of the metal pin 220 is uniform, see Figure 7 Therefore, stress will inevitably be generated when bending under the action of external force, which will lead to a gap between the metal pin 220 and the plastic part, providing a channel for water vapor to enter the interior of the LED lamp bead. In the present application, reducing the width of the third connecting section 225 will not affect the supporting performance of the metal bracket 200, but also reduce the stress when forming the third connecting section 225 and the welding section 222, thereby reducing the impact on the airtightness of the LED lamp bead structure when the connecting section 221 and the welding section 222 are bent, reducing the difficulty of the LED lamp bead manufacturing process, and improving the quality of the LED lamp bead.

[0056] Preferably, both ends of the light emitting chip 100 are connected to the metal bracket 200 through bonding wires 600 to realize electrical connection between the light emitting chip 100 and the metal substrate 210, and fixed to the PCB board through the welding section 222. The bonding wire 600 can be one or a combination of gold wire, copper wire, silver wire, aluminum wire, gold-clad silver wire, and alloy wire. The light emitting chip 100 can be single, double, or multiple, and the luminous color can be one or a combination of single color, double color, and multiple colors.

[0057] The existing lamp bead structure is generally a six-pin structure, please refer to Figure 8 , and the appearance is different, which may cause the polarity to be misidentified when the LED is mounted on the client, resulting in the LED mounting error and prolonged mounting time. Optionally, the front and / or back of the reflector cup 300 is provided with an identification structure 700 for locating and identifying the polarity of the LED lamp bead, for example, see Figure 3 The front of the reflector cup 300 is provided with a notch, which can be used as a positioning point for the LED lamp bead structure, so as to facilitate accurate positioning during the preparation process. Fig. 9 The back of the reflective cup 300 is provided with an identification structure 700 to facilitate the identification of polarity during mounting by the client. The identification structure 700 may be of a special shape.

[0058] Correspondingly, the second aspect of the present invention further provides a method for preparing the LED lamp bead structure with high airtightness, comprising:

[0059] (1) providing a metal plate and processing it to form a preliminary shape of the metal bracket 200;

[0060] (2) Injection molding to obtain a reflector cup 300, and wrap the metal substrate 210 in (1) therein, with the lower surface of the metal substrate 210 being not lower than the bottom surface of the reflector cup 300, and then cooling and solidifying to obtain a semi-finished lamp bead bracket;

[0061] (3) Processing the semi-finished lamp bead bracket obtained in (2) to bend the metal pin 220 into a shape to obtain a finished lamp bead bracket;

[0062] (4) Fixing the light emitting chip 100 on the metal substrate 210 and electrically connecting the light emitting chip 100 and the metal substrate 210;

[0063] (5) Fill the reflective cup 300 with sealant, bake and cure it, and complete the packaging.

[0064] The present invention will be further described below with specific embodiments:

[0065] Example 1

[0066] This embodiment provides a highly airtight LED lamp bead structure, comprising: a light-emitting chip, and a lamp bead bracket for fixing and installing the light-emitting chip;

[0067] The lamp bead bracket includes a metal bracket and a reflective cup wrapping the metal bracket, wherein the metal bracket includes a metal substrate for fixing and mounting the light-emitting chip, and a metal pin connected to the substrate;

[0068] The metal pin includes a connecting section and a welding section, the connecting section is connected to the welding section after being bent downward from the metal substrate twice continuously, and the connecting section includes a first connecting section, a second connecting section and a third connecting section which are sequentially connected between the metal substrate and the welding section;

[0069] The metal substrate is located in the inner cavity of the reflector cup, and the lower surface of the metal substrate is not lower than the bottom surface of the reflector cup, so that at least a part of the first connecting section is located in the inner cavity of the reflector cup.

[0070] The two ends of the light emitting chip are connected to the metal bracket through bonding wires to achieve electrical connection between the light emitting chip and the metal substrate, and are fixed to the PCB board through the welding section. The interior of the reflective cup is filled with packaging glue for sealing and protecting the light emitting chip.

[0071] Specifically, the reflector cup is a bowl-cup structure with a circular cup mouth, the cup depth H1 of the reflector cup is 0.7 mm, and the vertical height H2 between the upper surface of the metal substrate and the bottom surface of the reflector cup is 200 μm. The first connecting section forms an angle θ (θ=80°) with the bottom of the reflector cup, and the bottom edge of the reflector cup contacts the first connecting section, so that the upper surface of the first connecting section and the inner wall of the reflector cup form a groove. The vertical height H3 of the first connecting section is 0.735 mm, and the length of the second connecting section is 20% of the outer diameter of the reflector cup.

[0072] The method for preparing a high airtight LED lamp bead structure includes:

[0073] (1) providing a metal plate and processing it to form a preliminary shape of a metal bracket;

[0074] (2) injection molding to obtain a reflective cup, and wrapping the metal substrate in (1) therein, with the lower surface of the metal substrate being not lower than the bottom surface of the reflective cup, and then cooling and solidifying to obtain a semi-finished lamp bead bracket;

[0075] (3) processing the semi-finished lamp bead bracket obtained in (2) to bend the metal pins into shape to obtain a finished lamp bead bracket;

[0076] (4) Fixing the light-emitting chip on the metal substrate and electrically connecting the light-emitting chip and the metal substrate;

[0077] (5) Fill the reflector cup with sealant, bake and cure it to complete the packaging.

[0078] Example 2

[0079] This embodiment provides a highly airtight LED lamp bead structure, which is basically the same as the structure of Embodiment 1, except that:

[0080] The third connecting section is an I-shaped structure, so that the side surface of the metal pin is in an I-shape.

[0081] The preparation method in Example 1 was used to prepare a LED lamp bead structure with high airtightness.

[0082] Example 3

[0083] This embodiment provides a highly airtight LED lamp bead structure, which is basically the same as the structure of Embodiment 2, except that:

[0084] The front side of the reflector cup is provided with a notch as a positioning point of the LED lamp bead structure, and the back side of the reflector cup is provided with a marking structure with a special shape as a polarity identification structure during client mounting.

[0085] The preparation method in Example 1 was used to prepare a LED lamp bead structure with high airtightness.

[0086] Example 4

[0087] This embodiment provides a highly airtight LED lamp bead structure, which is basically the same as the structure of Embodiment 2, except that:

[0088] The cup depth H1 of the reflector cup is 0.7 mm, and the vertical height H2 between the upper surface of the metal substrate and the bottom surface of the reflector cup is 300 μm. The first connecting section forms an angle θ (θ=75°) with the bottom of the reflector cup, and the bottom edge of the reflector cup contacts the first connecting section, so that the upper surface of the first connecting section and the inner wall of the reflector cup form a groove. The vertical height H3 of the first connecting section is 0.735 mm, and the length of the second connecting section is 15% of the outer diameter of the reflector cup.

[0089] Example 5

[0090] This embodiment provides a highly airtight LED lamp bead structure, which is basically the same as the structure of Embodiment 2, except that:

[0091] The cup depth H1 of the reflector cup is 0.7 mm, and the vertical height H2 between the upper surface of the metal substrate and the bottom surface of the reflector cup is 200 μm. The first connecting section forms an angle θ (θ=80°) with the bottom of the reflector cup, and the bottom edge of the reflector cup contacts the first connecting section, so that the upper surface of the first connecting section and the inner wall of the reflector cup form a groove. The vertical height H3 of the first connecting section is 0.735 mm, and the length of the second connecting section is 10% of the outer diameter of the reflector cup.

[0092] Example 6

[0093] This embodiment provides a highly airtight LED lamp bead structure, which is basically the same as the structure of Embodiment 2, except that:

[0094] The cup depth H1 of the reflector cup is 0.7 mm, and the vertical height H2 between the upper surface of the metal substrate and the bottom surface of the reflector cup is 200 μm. The first connecting section forms an angle θ (θ=90°) with the bottom of the reflector cup, and the bottom edge of the reflector cup contacts the first connecting section, so that the upper surface of the first connecting section and the inner wall of the reflector cup form a groove. The vertical height H3 of the first connecting section is 0.735 mm.

[0095] Control group

[0096] by Figure 1 and Figure 2 The LED lamp bead structure shown is the control group.

[0097] Performance Testing

[0098] The air tightness and luminous brightness of the LED lamp bead structure obtained in the embodiment and the LED lamp bead structure in the control group were tested under the conditions of R: 15mA, G: 8mA, and B: 5mA, wherein the luminous brightness was calculated based on the control group;

[0099] The airtightness test method is: the heating table temperature is 160℃, the red ink mixture (red ink: alcohol = 1:1 volume ratio) in the test cup is boiled, the LED lamp beads in the embodiment and the control group are immersed in this mixture, and the LED lamp beads are taken out after 8 hours, the bowl and cup are physically removed, and the color changes of the front and back of the luminous metal functional area of ​​the LED lamp beads are observed to confirm the penetration of the red ink. It is stipulated that if there is no color change on the front of the LED lamp bead functional area and no color change on the back of the metal functional area after 8 hours, it is recorded as good; if there is no color change on the metal functional area of ​​the lamp bead and there is a slight color change on the back of the metal functional area, it is recorded as good; if there is a slight color change on the metal functional area of ​​the lamp bead, it is recorded as fair.

[0100] The test results are shown in Table 1 below.

[0101] Airtightness Luminance Example 1 better 110％ Example 2 good 110％ Example 3 good 110％ Example 4 better 106％ Example 5 better 105％ Example 6 better 105％ Control group generally 100％

[0102] It can be seen from the above results that in the present invention, on the basis of the original metal bracket structure, the position of the functional area is adjusted so that the height of the functional area is not lower than the bottom of the reflective cup, and at least part of the first connecting section is located in the inner cavity of the reflective cup, thereby improving the brightness and airtightness of the lamp bead, reducing the use of packaging glue, reducing the structural cost of the LED lamp bead, and at the same time reducing the difficulty of the LED lamp bead manufacturing process and improving the quality of the LED lamp bead.

[0103] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A highly airtight LED lamp bead structure, characterized in that: include: A light-emitting chip and a lamp bead bracket for fixing and installing the light-emitting chip; The lamp bead bracket includes a metal bracket and a reflective cup wrapping the metal bracket, wherein the metal bracket includes a metal substrate for fixing and mounting the light-emitting chip, and a metal pin connected to the substrate; The metal pin includes a connecting section and a welding section, the connecting section is connected to the welding section after being bent downward from the metal substrate twice continuously, and the connecting section includes a first connecting section, a second connecting section and a third connecting section which are sequentially connected between the metal substrate and the welding section; The metal substrate is located in the inner cavity of the reflector cup, and the lower surface of the metal substrate is not lower than the bottom surface of the reflector cup, so that at least part of the first connecting section is located in the inner cavity of the reflector cup; The ratio of the vertical height of the first connecting section to the cup depth of the reflective cup is (1.05-1.34):

1.

2. The highly airtight LED lamp bead structure as claimed in claim 1, characterized in that: The first connecting section and the bottom of the reflective cup form an angle, and the angle is less than 90°.

3. The highly airtight LED lamp bead structure as claimed in claim 2, characterized in that: The angle is 75° to 85°.

4. The highly airtight LED lamp bead structure according to any one of claims 1 to 3, characterized in that: The first connecting section and the inner wall of the reflective cup form a groove.

5. The highly airtight LED lamp bead structure as claimed in claim 1, characterized in that: The vertical height between the upper surface of the metal substrate and the bottom surface of the reflective cup is 2.5% to 10% of the cup depth of the reflective cup.

6. The highly airtight LED lamp bead structure according to any one of claims 1 to 3, characterized in that: The length of the second connecting section is 15% to 25% of the outer diameter of the reflector cup.

7. The highly airtight LED lamp bead structure according to claim 1, characterized in that: The metal substrate, the connecting section and the welding section are integrally formed, and the third connecting section is an I-shaped structure, so that the side surface of the metal pin is in an I-shape.

8. The highly airtight LED lamp bead structure as claimed in claim 1, characterized in that: The reflective cup is formed by stamping and injection molding of a plastic material, and the reflective cup is a bowl-cup structure with a circular cup mouth; The interior of the reflective cup is filled with packaging glue for sealing and protecting the light-emitting chip.

9. The highly airtight LED lamp bead structure according to claim 1, characterized in that: The front and / or back of the reflective cup is provided with an identification structure for locating and identifying the polarity of the LED lamp beads; Two ends of the light emitting chip are connected to the metal bracket through bonding wires and are fixed to the PCB board through the welding section.

10. The method for preparing a highly airtight LED lamp bead structure according to any one of claims 1 to 9, characterized in that: include: (1) providing a metal plate and processing it to form a preliminary shape of a metal bracket; (2) injection molding to obtain a reflective cup, and wrapping the metal substrate in (1) therein, with the lower surface of the metal substrate being not lower than the bottom surface of the reflective cup, and then cooling and solidifying to obtain a semi-finished lamp bead bracket; (3) processing the semi-finished lamp bead bracket obtained in (2) to bend the metal pins into shape to obtain a finished lamp bead bracket; (4) Fixing the light-emitting chip on the metal substrate and electrically connecting the light-emitting chip and the metal substrate; (5) Fill the reflector cup with sealant, bake and cure it to complete the packaging.

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