A surface-mount LED display chip and its manufacturing process

Abstract

This invention discloses a surface-mount LED display chip and its manufacturing process, relating to the field of LED display chips. By sequentially arranging a lower reflector ring, an upper reflector ring, and a lampshade on a base, this invention forms a reasonable light reflection and focusing path. The lower and upper reflector rings have different inward tilt angles, allowing light to undergo secondary refraction and reflection within the lampshade, significantly improving luminous uniformity and brightness output while reducing light spot divergence and enhancing the overall display effect. An auxiliary assembly device is introduced during the manufacturing process. This device stably supports and clamps the base, enabling multi-angle position adjustment. Combined with external assembly equipment, it completes the assembly process, avoiding offsets and errors caused by manual assembly, improving assembly accuracy and yield. By controlling process parameters such as die-bonding temperature, welding tension, and reflector ring angle, the heat dissipation performance and electrical connection reliability of the LED chip are ensured.

Description

Technical Field

[0001] This invention relates to the field of LED display lamp beads, and more particularly to a surface mount LED display lamp bead and its manufacturing process. Background Technology

[0002] Currently, LED displays are widely used in advertising, stage performances, traffic signs, and information displays. Among these, the surface-mount LED chips, as the core light-emitting unit, directly affect the brightness uniformity and lifespan of the display screen due to their luminous efficiency and assembly precision. Most existing surface-mount LED chips consist of a base, reflector ring, LED chip, and lens. While these components can meet basic light-emitting requirements, they still have the following shortcomings in practical use: First, the reflector ring structure is too simple, making it easy for light to diverge or become uneven in the light path, resulting in bright or dark spots in localized areas of the display screen, affecting the overall display effect. Second, the assembly process relies on manual operation or single-equipment positioning, which can easily lead to misalignment between the base, reflector ring, and lamp cover, resulting in unstable optical performance and a low yield rate. Third, some products lack sufficient control in the soldering and die bonding processes, leading to poor chip heat dissipation performance and a tendency for light decay or failure after long-term use. Summary of the Invention

[0003] Therefore, in order to overcome the above-mentioned shortcomings, the present invention provides a surface-mount LED display chip and its manufacturing process.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a surface-mount LED display lamp bead, comprising a base for support, pins mounted on both sides of the base, a lower reflector ring mounted on the top of the base, an upper reflector ring disposed on the top of the lower reflector ring, a lamp cover disposed at the upper end of the upper reflector ring, a chip mounted in the middle of the base, and a card hole disposed at the middle of the bottom end of the base, wherein the inner side of the lower reflector ring is tilted in the opposite direction to the upper reflector ring, and the upper end of the inner side of the upper reflector ring is tilted downward at a smaller angle than the tilt angle of the inner side of the lower reflector ring.

[0005] The preferred production process consists of the following steps:

[0006] S1 selects a base that meets the design specifications. The material is ceramic, and the dimensional tolerance is controlled within ±0.02mm. An ultrasonic cleaner is used. 2% isopropanol is added to deionized water and ultrasonically cleaned for 5 minutes at a frequency of 40kHz and a power of 150W. After cleaning, the base is placed in an 80℃ oven to dry for 15 minutes to ensure that there is no moisture or impurities on the surface.

[0007] S2 places the base into the auxiliary assembly device for installation;

[0008] S3 applies silver paste to the center of the base, with the amount of paste applied controlled at 0.08-0.12mg. The LED chip is accurately placed using a die bonder with a positioning accuracy of ±5μm. The silver paste is then cured in a thermal curing oven at 150℃ for 1.5 hours. After curing, the shear strength of the paste is ≥20MPa.

[0009] S4 adjusts the auxiliary assembly device so that the pin soldering surface faces upwards, and uses a gold wire ball soldering machine for bonding. The gold wire diameter is 25μm, the bonding pressure is 0.35N, the ultrasonic power is 80mW, and the solder joint pull test is ≥49mN.

[0010] S5 adjusts the angle of the auxiliary assembly device so that the top of the base faces upwards. The lower reflector ring is fixed by dispensing glue, and the amount of glue is controlled to be evenly distributed around the ring opening, with 0.05-0.07mg of epoxy glue per dot. The press-fit alignment accuracy is ±0.03mm.

[0011] The S6 has an upper reflector installed above the lower reflector, with the coaxiality controlled to ≤0.05mm. The normal of the inner inclined surface of the upper reflector d forms an angle of 20°-25° with respect to the normal of the upper surface of the base, making its inner side inclined downward towards the LED chip. The normal of the inner inclined surface of the lower reflector forms an angle of 30°-35° with respect to the normal of the upper surface of the base, making its inner side inclined upward towards the lamp cover. The curing temperature of the fixing adhesive is 120℃, and the curing time is 30 minutes.

[0012] The S7 lampshade uses an epoxy resin lens with a light transmittance of ≥95%, an embedding depth of 0.8±0.05mm, and a pressing force maintained at 1.5-2.0N;

[0013] S8 Check the bottom of the base for the retaining hole; the diameter tolerance should be controlled within ±0.02mm.

[0014] Preferably, the auxiliary assembly device includes a mounting plate, a first motor located on the right side of the mounting plate, a second motor located below the mounting plate, a connecting assembly located on the back of the mounting plate and connected to the output shaft of the first motor, a gear located inside the connecting assembly, a connector penetrating the connecting assembly and connected to the gear, and a lifting assembly located inside the connector. The second motor is located at the bottom of the connecting assembly and its top output shaft is connected to the gear.

[0015] Preferably, the connector is arc-shaped, and the outer side of the connector is provided with protruding teeth that mesh with the gear.

[0016] Preferably, the connecting assembly includes a rotating disk disposed on the back of the mounting plate and connected to the output shaft of the first motor, a guide member disposed at the other end of the rotating disk, and a connecting plate installed at the bottom of the guide member. The bottom of the connecting plate is connected to the second motor, and a connecting member is embedded in the rear end of the guide member.

[0017] Preferably, the guide member has a hollow center and a concave arc shape at the rear end.

[0018] Preferably, the lifting assembly includes a support column connected to the connector, a support member disposed on the back of the support column, a support member installed on the back of the support member, a fixing cylinder disposed at the bottom of the support member, a first gas spring disposed inside the fixing cylinder, a locking post connected to the top push rod of the first gas spring, a second gas spring disposed inside the support column, and a fixing post connected to the rear push rod of the second gas spring.

[0019] Preferably, the top of the locking post extends through the top of the support member, and an insertion hole is provided at the front end of the support member, with the fixing post tightly embedded inside the insertion hole.

[0020] Preferably, the fixing post and the locking post are frustum-shaped.

[0021] The beneficial effects of this invention are:

[0022] This invention creates a rational light reflection and focusing path by sequentially arranging a lower reflective ring, an upper reflective ring, and a lampshade on a base. The lower and upper reflective rings have different inward tilt angles, allowing light to undergo secondary refraction and reflection within the lampshade. This significantly improves light emission uniformity and brightness output while reducing light spot divergence and enhancing the overall display effect. An auxiliary assembly device is introduced during the manufacturing process. This device stably supports and clamps the base and allows for multi-angle position adjustment. Working in conjunction with external assembly equipment, it completes the assembly process, avoiding offsets and errors caused by manual assembly, thus improving assembly accuracy and yield. By controlling process parameters such as die bonding temperature, welding tension, and reflective ring angle, not only is the heat dissipation performance and electrical connection reliability of the LED chip ensured, but the overall structural stability and optical performance of the LED chip are also guaranteed. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the exploded structure of the present invention;

[0025] Figure 3 This is a cross-sectional structural diagram of the present invention;

[0026] Figure 4 This is a schematic diagram of the auxiliary assembly device of the present invention;

[0027] Figure 5 This is a schematic diagram of the connecting component structure of the present invention;

[0028] Figure 6 This is a schematic diagram of the lifting component structure of the present invention;

[0029] Figure 7 This is a side view of the lifting component of the present invention;

[0030] Figure 8 This is a schematic diagram of part of the auxiliary assembly device of the present invention.

[0031] The components are: base-a, pin-b, lower reflector ring-c, upper reflector ring-d, lampshade-e, LED chip-f, clip-g, mounting plate-1, first motor-2, second motor-3, connecting assembly-4, gear-5, connector-6, lifting assembly-7, rotating disk-41, guide-42, connecting plate-43, support column-71, support member-72, bracket-73, fixing cylinder-74, first gas spring-75, clip-76, second gas spring-77, and fixing column-78. Detailed Implementation

[0032] To further explain the technical solution of the present invention, a detailed description is provided below through specific embodiments.

[0033] Please see Figures 1-3 This invention provides a surface-mount LED display chip, including a base a for support, pins b installed on both sides of the base a at the front and rear positions, a lower reflector ring c fixed on the top of the base a, an upper reflector ring d installed on the top of the lower reflector ring c, a lamp cover e embedded in the upper end of the upper reflector ring d, an LED chip f embedded in the middle of the base a, and a locking hole g for connection and fixation in the lower center of the base a. The inner side of the lower reflector ring c is tilted in the opposite direction to the upper reflector ring d, and the upper end of the inner side of the upper reflector ring d is tilted downward, with the tilt angle being smaller than the tilt angle of the inner side of the lower reflector ring c.

[0034] A manufacturing process for surface-mount LED display chips includes the following steps: S1. Base pretreatment: Select a base a that meets the design specifications. The material is generally ceramic, and the dimensional tolerance is controlled within ±0.02mm. Use an ultrasonic cleaner to add 2% isopropanol to deionized water and ultrasonically clean for 5 minutes at a frequency of 40kHz and a power of 150W. Place the cleaned base a in an 80℃ oven to dry for 15 minutes to ensure that the surface is free of moisture and impurities. S2. Base fixing: Place the base a into the lifting and clamping mechanism of the auxiliary assembly device to avoid damaging the base. The angle adjustment accuracy of the auxiliary assembly device is ±1° to ensure the levelness of the base a. S3. LED chip embedding: ... The middle of base a is coated with silver paste, with the amount of paste controlled between 0.08-0.12mg. The LED chip f is accurately placed using a die bonder, with a positioning accuracy of ±5μm. The silver paste is then cured in a thermosetting oven at 150℃ for 1.5 hours, resulting in a shear strength ≥20MPa after curing. For S4, pin soldering, the auxiliary assembly device is adjusted so that the soldering surface of pin b faces upwards. Gold wire ball bonding is performed using a 25μm diameter gold wire, a bonding pressure of 0.35N, and an ultrasonic power of 80mW. The solder joint pull test results in a strength ≥49mN to ensure reliability. For S5, the lower reflector ring is installed. The angle of the auxiliary assembly device is adjusted so that the top of base a faces upwards, and the lower reflector ring is fixed using a dispensing method. For ring c, the amount of epoxy adhesive applied should be evenly distributed around the ring opening, with each spot containing 0.05-0.07 mg of epoxy adhesive. The alignment accuracy during press-fitting should be ±0.03 mm. For the S6 upper reflector ring installation, install the upper reflector ring d above the lower reflector ring c. The coaxiality between the upper and lower rings should be controlled to ≤0.05 mm. The tilt angles are as follows: the normal of the inner tilted surface of the upper reflector ring d forms a 20°-25° angle with the normal of the upper surface of the base, causing its inner side to tilt downwards towards the LED chip. The normal of the inner tilted surface of the lower reflector ring forms a 30°-35° angle with the normal of the upper surface of the base, causing its inner side to tilt upwards towards the lampshade, ensuring a stable shape. Achieve reasonable light distribution; fix the adhesive and cure at 120℃ for 30 minutes; S7 Lampshade embedding: lampshade e uses an epoxy resin lens with a light transmittance ≥95%, embedded to a depth of 0.8±0.05mm, with pressing force maintained at 1.5-2.0N to avoid damaging the chip; S8 Card hole positioning and fixing: check the bottom card hole g of base a, with diameter tolerance controlled within ±0.02mm to ensure subsequent mounting does not loosen; S9 Photoelectric performance testing: luminous intensity ≥1200mcd, wavelength deviation ≤±2nm; Thermal performance testing: junction temperature test at 25℃, chip junction temperature does not exceed 85℃; Appearance inspection: microscopic inspection for no bubbles, no misalignment, and no scratches.

[0035] Please see Figure 4The auxiliary assembly device includes a mounting plate 1 for support. A first motor 2 is locked to the right side of the mounting plate 1. The output shaft of the first motor 2 is connected to a connecting component 4 on the left side. The bottom of the connecting component 4 is connected to a second motor 3. A gear 5 that connects to the output shaft of the second motor 3 is embedded in the connecting component 4. A connecting piece 6 is mated to the left side of the gear 5. The connecting piece 6 is arc-shaped and passes through the connecting component 4. The outer side of the connecting piece 6 is provided with protruding teeth that mesh with the gear 5. A lifting component 7 is connected to the inner side of the connecting piece 6. The lifting component 7 is used to connect to the locking hole g at the bottom of the base a to lift the entire lamp bead processing process.

[0036] Please see Figure 5 The connecting component 4 includes a rotating disk 41 connected to the output shaft of the first motor 2. A guide 42 is welded to the back of the rotating disk 41. The guide 42 is hollow in the middle and has an inwardly concave arc shape at the rear end. The middle of the guide 42 is the mounting position of the gear 5. The inner rear end is embedded with a connector 6. A connecting plate 43 for mounting the second motor 3 is fixed at the bottom of the guide 42.

[0037] Please see Figures 6-7 The lifting assembly 7 includes a support column 71 fixed inside the connector 6. A support member 72 is welded to the back of the support column 71. A support member 73 is provided on the back of the support member 72. A fixing cylinder 74 is installed in the middle of the bottom end of the support member 73. A first gas spring 75 is provided inside the fixing cylinder 74. The top push rod of the first gas spring 75 is connected to a locking post 76. The top of the locking post 76 passes through the top of the support member 73. A second gas spring 77 is provided inside the support column 71. The rear push rod of the second gas spring 77 passes through the support member 72 and is connected to a fixing post 78. An insertion hole is opened at the front end of the support member 73. The fixing post 78 is tightly embedded in the insertion hole. The fixing post 78 and the locking post 76 are frustum-shaped.

[0038] The specific implementation process of the auxiliary assembly device is as follows:

[0039] When the auxiliary assembly device is needed, the base a is first placed on top of the support 73 by an external robotic arm. Then, the first gas spring 75 is activated to push the locking post 76 into the locking hole g, thus fixing the base a. After fixing, the lamp bead can be assembled with external equipment. The support position can be selected according to the size of the base a. When processing smaller lamp beads, the second gas spring 77 is activated to retract the fixing post 78, and the entire support 73 can be removed. Then, the small lamp bead base is placed on top of the support 72 and fixed by inserting the fixing post 78 into the locking hole. The angle and position can be adjusted during the assembly process.

[0040] When the first motor 2 is started, it rotates the connecting component 4, which in turn rotates the entire lifting component 7 along with the connecting piece, thus achieving angle adjustment. If vertical plane position adjustment is required, the second motor 3 is started, which rotates the gear 5. During the rotation of the gear 5, the connecting piece 6 moves along with it. The connecting piece 6 can then move under the guidance of the guide 42, and during the movement, the connecting piece 6 can move along with the lifting component 7, thus achieving vertical plane position adjustment.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A manufacturing process for surface-mount LED display chips, characterized in that: The specific steps are as follows: S1 selects a base that meets the design specifications. The material is ceramic, and the dimensional tolerance is controlled within ±0.02mm. An ultrasonic cleaner is used. 2% isopropanol is added to deionized water and ultrasonically cleaned for 5 minutes at a frequency of 40kHz and a power of 150W. After cleaning, the base is placed in an 80℃ oven to dry for 15 minutes to ensure that there is no moisture or impurities on the surface. S2 places the base into the auxiliary assembly device for installation; S3 applies silver paste to the center of the base, with the amount of paste applied controlled at 0.08-0.12mg. The LED chip is accurately placed using a die bonder with a positioning accuracy of ±5μm. The silver paste is then cured in a thermal curing oven at 150℃ for 1.5 hours. After curing, the shear strength of the paste is ≥20MPa. S4 adjusts the auxiliary assembly device so that the pin soldering surface faces upwards, and uses a gold wire ball soldering machine for bonding. The gold wire diameter is 25μm, the bonding pressure is 0.35N, the ultrasonic power is 80mW, and the solder joint pull test is ≥49mN. S5 adjusts the angle of the auxiliary assembly device so that the top of the base faces upwards. The lower reflector ring is fixed by dispensing glue, and the amount of glue is controlled to be evenly distributed around the ring opening, with 0.05-0.07mg of epoxy glue per dot. The press-fit alignment accuracy is ±0.03mm. The S6 has an upper reflector installed above the lower reflector, with the coaxiality controlled to ≤0.05mm. The normal of the inner inclined surface of the upper reflector forms an angle of 20°-25° with respect to the normal of the upper surface of the base, making its inner side inclined downward towards the LED chip. The normal of the inner inclined surface of the lower reflector forms an angle of 30°-35° with respect to the normal of the upper surface of the base, making its inner side inclined upward towards the lampshade. The curing temperature of the fixing adhesive is 120℃, and the curing time is 30 minutes. The S7 lampshade uses an epoxy resin lens with a light transmittance of ≥95%, an embedding depth of 0.8±0.05mm, and a pressing force maintained at 1.5-2.0N; S8 Check the bottom of the base for the retaining hole; the diameter tolerance should be controlled within ±0.02mm. The auxiliary assembly device includes a mounting plate, a first motor located on the right side of the mounting plate, a second motor located below the mounting plate, a connecting assembly located on the back of the mounting plate and connected to the output shaft of the first motor, a gear located inside the connecting assembly, a connector penetrating the connecting assembly and connected to the gear, and a lifting assembly located inside the connector. The second motor is located at the bottom of the connecting assembly and its top output shaft is connected to the gear.

2. The manufacturing process of a surface-mount LED display lamp bead according to claim 1, characterized in that: The connector is arc-shaped, and the outer side of the connector is provided with protruding teeth that mesh with the gear.

3. The manufacturing process of a surface-mount LED display lamp bead according to claim 1, characterized in that: The connecting assembly includes a rotating disk located on the back of the mounting plate and connected to the output shaft of the first motor, a guide member located at the other end of the rotating disk, and a connecting plate installed at the bottom of the guide member. The bottom of the connecting plate is connected to the second motor, and a connecting member is embedded in the rear end of the guide member.

4. The manufacturing process of a surface-mount LED display lamp bead according to claim 3, characterized in that: The guide component is hollow in the middle and has an inwardly concave arc shape at the rear end.

5. The manufacturing process of a surface-mount LED display lamp bead according to claim 3, characterized in that: The lifting assembly includes a support column connected to the connector, a support member located on the back of the support column, a support member installed on the back of the support member, a fixing cylinder located at the bottom of the support member, a first gas spring located inside the fixing cylinder, a locking post connected to the top push rod of the first gas spring, a second gas spring located inside the support column, and a fixing post connected to the rear push rod of the second gas spring.

6. The manufacturing process of a surface-mount LED display lamp bead according to claim 5, characterized in that: The top of the card post extends through the top of the support, and an insertion hole is provided at the front end of the support, into which the fixing post is tightly embedded.

7. The manufacturing process of a surface-mount LED display lamp bead according to claim 6, characterized in that: The fixing post and the clamping post are in the shape of a frustum.

8. A surface-mount LED display chip, using the manufacturing process of a surface-mount LED display chip as described in claim 1, characterized in that: The device includes a base for support, pins mounted on both sides of the base, a lower reflector ring mounted on the top of the base, an upper reflector ring positioned above the lower reflector ring, a lampshade positioned at the upper end of the upper reflector ring, a chip mounted in the middle of the base, and a locking hole positioned at the middle of the bottom end of the base. The inner side of the lower reflector ring is tilted in the opposite direction to the upper reflector ring, and the upper end of the inner side of the upper reflector ring is tilted downwards at a smaller angle than the tilt angle of the inner side of the lower reflector ring.

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