Preparation process of RGB three-color integrated packaging light bar and light bar

Abstract

The preparation process of the RGB three-color integrated packaging light bar comprises the steps that wafers of multiple colors are provided and fixed to a bonding pad, electrodes of the wafers are connected with pins of a substrate through ultrasonic welding, a current path is formed, the wafers are subjected to potting or injection molding through glue, and the LED light bar is obtained. And forming a lens covering the wafer, baking for a preset time in a preset temperature range to enable the colloid to be completely crosslinked, and classifying based on the allowable deviation of wavelength, the allowable deviation of brightness and the allowable deviation of color temperature. Compared with the prior art, by adding the multi-color wafers, a red spectrum is supplemented, so that the color gamut range of a display screen of professional equipment is increased, and moreover, the preparation process can maintain low-current white light under the condition of realizing color gamut improvement, and can realize RGB (Red, Green and Blue) packaging under relatively small 4014 packaging and 7020 packaging.

Description

Technical Field

[0001] The present invention relates to the technical field of light bars, and in particular to a preparation process of an RGB three-color integrated package light bar and the light bar. Background Art

[0002] SMD light strips (surface mount diode light strips) are a type of LED light strip commonly used for lighting and decoration. Unlike traditional LED bulbs, SMD light strips use surface mount technology to mount small LED chips directly on a flexible circuit board to form a continuous light strip.

[0003] With the emergence of high-end monitors, the color gamut requirements for SMD light strips have further increased, gradually penetrating into the professional display field. Therefore, BG chips are usually used to achieve color gamut improvement. However, under low current, the existing BG chips have a green light, which is not conducive to the visual experience. SMD packaging is a more common packaging method for LED lights. The 4014 package and the 7020 package are two types of SMD packages. Currently, side-entry lamp beads generally use a combination of blue chips and yellow phosphors, usually at 60%-75% NTSC (corresponding to sRGB 80%-95%), which meets daily lighting and basic display needs. However, the high color gamut requirements for high-end displays are difficult to achieve. In some professional applications (including but not limited to photo editing and editing), the color gamut is difficult to meet the requirements. Summary of the Invention

[0004] The present invention provides a preparation process for an RGB three-color integrated package light bar and a light bar, which can solve the problem mentioned in the background technology that the color gamut of the light bar is difficult to meet the use requirements in some professional applications.

[0005] A preparation process of an RGB three-color integrated package light strip, comprising:

[0006] Provide chips of multiple colors and fix them to pads;

[0007] connecting the electrodes of the wafer to the pins of the substrate by ultrasonic welding to form a current path;

[0008] The wafer is potted or injection-molded with colloid to form a lens covering the wafer;

[0009] Bake within a preset temperature range for a preset time to completely cross-link the colloid;

[0010] Classification is based on the allowable deviation of wavelength, brightness, and color temperature.

[0011] Preferably, the chips include a red chip, a green chip and a blue chip, and by adjusting the brightness of the red chip, the green chip and the blue chip, the light emitted by them is mixed to generate white light or expand the color gamut.

[0012] Preferably, the chip is fixed to the pad by using silver glue or eutectic welding.

[0013] Preferably, a gold wire with a thickness of 15 μm to 25 μm is used to connect the chip and the electrode, wherein the tension of the solder joint is greater than 8 g and the curvature of the gold wire is between 100 μm and 300 μm.

[0014] Preferably, the encapsulation process is adjusted based on the type of the lens.

[0015] Preferably, the preset temperature range is 120°C-180°C.

[0016] Preferably, the preset time is 2h-4h.

[0017] Preferably, the allowable deviation of the wavelength is ±2 nm, the allowable deviation of the brightness is ±15%, and the allowable deviation of the color temperature is ±500K.

[0018] An RGB three-color integrated package light bar is manufactured using a manufacturing process for an RGB three-color integrated package light bar, comprising: a base, on which chips are fixedly mounted, wherein the chips include a red chip, a green chip, and a blue chip;

[0019] The wafer is covered with a lens, a bracket is fixedly mounted on the base, and a gasket for connecting a power supply is provided on the wafer.

[0020] Preferably, the base is made of PCT material, and the gasket is a copper-based silver-plated positive and negative electrode gasket.

[0021] Beneficial effects of the present invention:

[0022] In the present invention, by adding multi-color chips, the red spectrum is supplemented, thereby increasing the color gamut range of the display screen of professional equipment. Moreover, the preparation process can maintain low-current white light while achieving color gamut improvement, and can realize RGB packaging in smaller 4014 packages and 7020 packages. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Fig. 1 A flow chart of a preparation process of an RGB three-color integrated package light bar provided by the present invention;

[0024] Fig. 2 This is a structural schematic diagram of an RGB three-color integrated package light strip provided by the present invention.

[0025] Description of reference numerals:

[0026] 1. Red chip; 2. Green chip; 3. Blue chip; 4. Base; 5. Lens; 6. Bracket; 7. Gasket. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0028] SMD light strips (surface mount diode light strips) are a type of LED light strip commonly used for lighting and decoration. Unlike traditional LED bulbs, SMD light strips use surface mount technology to mount small LED chips directly on a flexible circuit board to form a continuous light strip.

[0029] In LED PKG technology, 4014 and 7020 packages are common LED lamp bead package types. 4014 indicates that the size of the LED chip is 4.0mm x 1.4mm, and 7020 indicates that the size of the LED chip is 7.0mm x 2.0mm. Depending on different lighting effects and power consumption requirements, the appropriate package type can be selected according to the application scenario.

[0030] Because existing BG chips emit green light at low current, this is unsightly and unsuitable for specialized applications (including but not limited to photo editing and editing). Existing edge-entry 4014 and 7020 packages typically use a blue chip + yellow phosphor combination to effectively implement the white light LED principle.

[0031] However, the inventors discovered that with the continuous development of display technology, professional monitors, televisions, and other applications requiring high color gamut and high brightness are increasing. Although the above-mentioned lamp bead combination can emit white light, the spectrum lacks the red spectrum, resulting in the color gamut in professional applications (such as photo editing, video editing, and color correction) not meeting the requirements. In addition, in smaller package sizes (such as the 4014 package), due to limited space, the heat dissipation and current carrying capacity are poor, further limiting the performance of the LED.

[0032] like Figs. 1-2 As shown, the embodiment of the present invention provides a preparation process of an RGB three-color integrated package light bar, including:

[0033] Chips of multiple colors are provided and fixed to pads using silver glue (also known as conductive glue) or eutectic soldering. The thickness uniformity of the silver glue affects the reliability of heat dissipation and die bonding.

[0034] Specifically, the chip utilizes a red chip 1, a green chip 2, and a blue chip 3. These chips can be arranged side by side or in a triangular layout, depending on the packaging specifications. By adjusting the brightness of the red chip 1, green chip 2, and blue chip 3, their light can be mixed to produce white light or expand the color gamut. The addition of the red chip 1 supplements the red spectrum, effectively increasing the color gamut of the display screen in the device in which it is used.

[0035] Furthermore, during the die bonding process, a high-precision placement machine (with a positioning accuracy within ±5μm, including but not limited to the ASMAD830 automatic die bonding machine) is required to fix the chip on the pad of the substrate to ensure electrode alignment. The material of the substrate includes but is not limited to ceramic, aluminum, copper, and PCB.

[0036] Wafer fixation not only requires precise positioning but also plays a crucial role in heat dissipation and the long-term reliability of the product. Silver adhesive is used to secure the wafer, and its thickness uniformity directly impacts heat conduction. Therefore, careful attention must be paid to the uniformity of the silver adhesive during operation. An uneven silver adhesive layer can easily lead to localized overheating or poor heat dissipation, reducing component performance and lifespan. Therefore, silver adhesive uniformity is crucial for heat dissipation and long-term reliability during the die bonding process.

[0037] After the die bonding is completed, the electrodes of the chip are connected to the pins of the substrate by ultrasonic welding to form a current path.

[0038] The bonding wires, made of 15-25μm gold wire, connect the wafer to the electrodes. During the bonding process, the tensile force at the solder joints must be greater than 8g, and the wire curvature must be between 100μm and 300μm to avoid breakage or short circuits.

[0039] Specifically, a tensile force exceeding 8g ensures a strong enough connection between the gold wire, the wafer, and the electrodes, preventing the light bar from becoming loose or causing poor contact due to external forces (such as vibration or temperature fluctuations) during operation. If the tensile force at the solder joint is insufficient, the gold wire may not be able to withstand the mechanical stress in certain operating environments and may break easily. Excessively low solder joint tensile force not only affects electrical performance but can also cause the entire device to fail.

[0040] During soldering, the curvature of the gold wire is crucial to preventing wire breakage. Maintaining a curvature between 100μm and 300μm prevents the wire from overstretching or becoming too tight, thereby improving its resistance to breakage. Furthermore, the wafer and electrodes experience temperature fluctuations during operation. The curvature of the wire helps the wire adapt to thermal expansion differences, reducing stress concentration caused by temperature fluctuations and preventing wire breakage or detachment.

[0041] Furthermore, limiting the wire's tension and curvature ensures long-term wire stability after soldering, preventing wire breakage, detachment, or short circuits caused by excessive curvature or tension. Short circuits typically occur when the wire shifts or has poor contact, and proper curvature and tension can mitigate this risk.

[0042] After welding is complete, the chip needs to be potted or injection molded with a colloid to form a lens 5 covering the chip. The qualification standard for lens 5 is: transmittance ≥ 95%. Lens 5 is an optical lens. The potting process is adjusted according to the specific use scenario of the light bar application to ensure that the final type of lens 5 (concentrating type or diffusing type) meets the use needs and further optimizes the light distribution. Lens 5 also provides physical protection for the chip, making it less susceptible to damage from external impact.

[0043] In this embodiment, the colloid is made of epoxy resin or silicone. These two materials are resistant to yellowing and have high light transmittance, thereby improving the quality of light emitted by the light strip and extending its service life.

[0044] It is understandable that the bracket 6 for mounting the chip and the lens 5 can be made of the same material and process, and the transmittance of the bracket 6 can be slightly lower than that of the lens 5, and the transmittance can be ≥90%.

[0045] After the encapsulation colloid is formed, it needs to be cured. During curing, a temperature range and time are preset: 120°C-180°C, and the time is preset to 2-4 hours. The epoxy resin or silicone is baked at 120°C-180°C for 2-4 hours to fully crosslink the epoxy resin or silicone, further improving its mechanical strength and weather resistance.

[0046] The cross-linking process chemically connects colloidal molecules into a larger, more stable network. This makes the colloid's molecular chains stronger and more stable, thereby increasing its resistance to external forces, temperature fluctuations, and environmental stresses. Colloidal materials used in LED packaging must withstand varying environmental conditions (temperature and humidity). Cross-linking stabilizes the colloid's structure, effectively preventing aging, deformation, and damage, and extending the life of the light strip.

[0047] As a thermochemical reaction, cross-linking requires a certain temperature to stimulate and accelerate the chemical reaction. The temperature range of 120℃-180℃ provides sufficient thermal energy to enable the reactive molecules in the colloid to effectively cross-link. If the temperature is too high, the colloid is prone to thermal degradation, resulting in a decrease in material performance. Therefore, choosing 120℃-180℃ as the curing temperature range can ensure the completion of the reaction while avoiding adverse reactions caused by excessive heating. By heating within this temperature range, the colloid can fully cross-link, forming a strong network structure, ultimately enhancing the overall performance of the LED light strip, especially its reliability and durability during long-term use.

[0048] Finally, classification is carried out based on the allowable deviation of wavelength, brightness and color temperature to ensure the consistency of the same batch of light strips.

[0049] Among them, the allowable deviation of wavelength is ±2nm, the allowable deviation of brightness is ±15%, and the allowable deviation of color temperature is ±500K.

[0050] During classification, a dynamic current compensation algorithm can be used to achieve a color temperature deviation of less than ±500K (5000K benchmark) in the low current range of 10mA-30mA, solving the low current color cast problem of the existing technology and maintaining a color accuracy of ΔE <1.5 at 1% brightness.

[0051] In this technology field, the size of the package limits the space available for each RGB LED. The 4014 package, commonly used in LED strips and small panels, is thinner and suitable for space-constrained applications. RGB LEDs in the 4014 package typically require a smaller chip design, increasing manufacturing complexity. The larger 7020 package provides more space for integrating the RGB chip and driver circuitry, making it suitable for applications requiring higher brightness, higher performance, and specialized features. Existing light strips combine a blue chip with yellow phosphor in a smaller 4014 package. Due to the relatively limited heat dissipation and current-carrying capacity of the smaller package, a low-current design is generally chosen to improve stability and extend lifespan. Light strips designed for low current often have difficulty fitting into the larger 7020 package. Low-current light strips in the larger 7020 package struggle to achieve the required brightness and power, resulting in an unsatisfactory color gamut for specialized applications.

[0052] In the present invention, through precise light distribution control of multiple color chips (red chip 1, green chip 2 and blue chip 3), that is, adjusting the brightness of red lens 1, green chip 2 and blue chip 3, a wide color gamut coverage of ≥90% NTSC can be achieved. Compared with the traditional combination of blue light + yellow phosphor, the color gamut range can be effectively improved, especially the intensity in the red spectrum segment (620nm-650nm) is effectively improved. It is suitable for presentation equipment that requires a higher color gamut and meets the 98% coverage requirement of Adobe RGB for professional monitors.

[0053] This process innovatively integrates chips in the side-entry 4014 and 7020 packages, shortening the light mixing distance. The integrated chip is combined with the potting or injection molding process of the lens 5, effectively improving the light efficiency utilization rate.

[0054] In this application, the red spectrum is supplemented by adding a red chip 1, thereby increasing the color gamut range of the display screen of professional equipment. Moreover, the present invention can maintain low-current white light while achieving color gamut improvement. By adding the red spectrum, the color gamut is effectively improved to meet the color accuracy requirements of professional applications. Through precise design, the RGB three-color integrated package light strip can achieve RGB packaging in both the smaller 4014 package and the 7020 package, and achieve high light efficiency and stability in the package to adapt to application scenarios with different sizes and power requirements.

[0055] The preparation process of this RGB three-color integrated package light strip is used in the field of professional monitors and televisions. By improving the color gamut range, it meets the color accuracy requirements of display devices, including but not limited to Adobe RGB and DCI-P3 wide color gamut display standards.

[0056] Applied in film and television production and image processing, the light strips produced by the preparation process of the RGB three-color integrated package light strip have excellent color reproduction capabilities, making the RGB three-color integrated package light strip more suitable for professional fields such as photo retouching, video editing and color correction.

[0057] Used in the fields of automotive and stage lighting, especially in automotive interior lighting and stage lighting design, RGB three-color integrated package light strips can provide rich color changes and higher brightness to meet special application requirements.

[0058] Applied in smart lighting systems, including but not limited to smart home and commercial lighting, RGB three-color integrated package light strips can adjust the lighting effect according to different scenes and needs to enhance the overall lighting effect.

[0059] In summary, through the innovative process of preparing RGB three-color integrated package light strips, the present invention not only optimizes the color gamut performance and heat dissipation performance of LED lamp beads, but also improves production efficiency and product consistency, and has broad market application prospects.

[0060] The specific steps of the preparation process of the RGB three-color integrated package light strip are as follows:

[0061] S1. Provide a red chip 1, a green chip 2, and a blue chip 3, and fix them to pads using silver glue or eutectic soldering.

[0062] S2. Connect the electrodes of the chip to the pins of the substrate through ultrasonic welding to form a current path.

[0063] S3. The chip is encapsulated with colloid to form a lens 5 covering the chip. The type of lens 5 is selected according to the application of the light bar.

[0064] S4. Bake at 120-180°C for 2-4 hours to completely cross-link the colloid.

[0065] S5. Classify based on the allowable deviation of wavelength, brightness and color temperature to ensure the consistency of the same batch of light strips.

[0066] In one embodiment, the present invention provides an RGB three-color integrated package light bar, which is manufactured using a preparation process for an RGB three-color integrated package light bar.

[0067] The RGB three-color integrated package light bar includes: a base 4 made of PCT material. A bracket 6 is fixedly mounted on the bottom of the base 4, and a chip is fixedly mounted on the top of the base 4. The chips include a red chip 1, a green chip 2, and a blue chip 3.

[0068] The chip is covered with a lens 5, and the chip is provided with a gasket 7 for connecting to a power source. The gasket 7 is a copper-based silver-plated positive and negative gasket. The gasket 7 is used to connect the power source and the chip to provide the required current through electrical connection.

[0069] The addition of red chip 1 expands the red spectrum, extending the color gamut of professional equipment displays. The light strip, manufactured using the RGB three-color integrated packaging process, achieves an enhanced color gamut while maintaining low-current white light, enabling RGB packaging in both the smaller 4014 and 7020 packages.

[0070] The above disclosures are only a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A preparation process for an RGB three-color integrated package light bar, characterized in that: include: Provide chips of multiple colors and fix them to pads; connecting the electrodes of the wafer to the pins of the substrate by ultrasonic welding to form a current path; The chip is potted or injection-molded with colloid to form a lens (5) covering the chip; Bake within a preset temperature range for a preset time to completely cross-link the colloid; Classification is based on the allowable deviation of wavelength, brightness, and color temperature.

2. The preparation process of the RGB three-color integrated package light bar according to claim 1, characterized in that: The chips include a red chip (1), a green chip (2) and a blue chip (3), and by adjusting the brightness of the red chip (1), the green chip (2) and the blue chip (3), the light emitted by the chips is mixed to generate white light or expand the color gamut.

3. The preparation process of the RGB three-color integrated package light bar according to claim 1, characterized in that: The chip is fixed to the pad by using silver glue or eutectic welding.

4. The preparation process of the RGB three-color integrated package light bar according to claim 1, characterized in that: Use 15μm-25μm gold wire to connect the chip and the electrode, where the solder joint tension is greater than 8g and the curvature of the gold wire is between 100μm-300μm.

5. The preparation process of the RGB three-color integrated package light bar according to claim 1, characterized in that: Based on the type of the lens (5), the potting process is adjusted.

6. The preparation process of the RGB three-color integrated package light bar according to claim 1, characterized in that: The preset temperature range is 120°C-180°C.

7. The preparation process of the RGB three-color integrated package light bar according to claim 1, characterized in that: The preset time is 2h-4h.

8. The preparation process of the RGB three-color integrated package light bar according to claim 1, characterized in that: The allowable deviation of the wavelength is ±2nm, the allowable deviation of the brightness is ±15%, and the allowable deviation of the color temperature is ±500K.

9. An RGB three-color integrated package light bar, characterized in that: The RGB three-color integrated package light strip is manufactured using the preparation process of any one of claims 1 to 8, comprising: a base (4), wherein the base (4) is fixedly mounted with chips, and the chips include a red chip (1), a green chip (2), and a blue chip (3); The wafer is covered with a lens (5), the base (4) is fixedly mounted with a bracket (6), and the wafer is provided with a gasket (7) for connecting to a power supply.

10. The RGB three-color integrated package light bar according to claim 9, characterized in that: The base (4) is made of PCT material, and the gasket (7) is a copper-based silver-plated positive and negative electrode gasket.

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