Design and process of mini backlight source

Abstract

The invention discloses a process of a mini backlight source, which comprises the following steps: irradiating a chip wafer through laser to enable the chip wafer to be nondestructively separated into a chip and a substrate, and mixing the chip with a guide solution to form a mixture; providing a surface-modified substrate, coating an electrode area on the surface of the substrate with a conductive adhesive, and then coating the mixture on the substrate to enable the chip to be aligned with the substrate; carrying out thermocuring on the substrate, evaporating the guide solution, curing the conductive adhesive, and coating a silica gel layer on the chip after the conductive adhesive is cured; nano-imprinting is conducted on the surface of the silica gel layer through a micro-lens mold, so that a micro-lens array structure is formed on the surface of the silica gel layer, and after the silica gel layer is cured, a mini backlight source prototype is obtained; and performing optical integration, mechanical packaging and LCD integration on the mini backlight source prototype to obtain the mini backlight source. According to the method, the guide solution is matched with the substrate with the modified surface to transfer the chip, so that the transfer speed of the chip is effectively increased, and the problem of low transfer rate of a huge amount is solved.

Description

Technical Field

[0001] The present invention relates to the field of mini backlight source manufacturing, and in particular to a mini backlight source design and process. Background Art

[0002] As a new generation of display technology, MiniLED backlight has broad market prospects in the fields of TV, display, car display and VR / AR equipment due to its advantages of high brightness, high contrast, low power consumption and long life. However, the manufacturing process of MiniLED backlight still faces many technical challenges, especially in the mass transfer link. Its low efficiency has become an important bottleneck restricting large-scale commercialization. The traditional Pick&Place method is slow due to its complicated operation, picking up and placing chips one by one. In addition, the small size of MiniLED chips requires extremely high transfer accuracy, which further increases the difficulty of operation. As a result, the number of chips transferred per hour is only between 10,000 and 100,000. The efficiency of massive transfer is low and cannot meet the needs of large-scale production.

[0003] Therefore, a mini backlight source design and process is proposed to solve the above-mentioned problem of low mass transfer rate. Summary of the invention

[0004] The purpose of the present invention is to provide a mini backlight source design and process to solve the problem of low mass transfer rate.

[0005] To achieve this object, the present invention adopts the following technical solutions: A process for a mini backlight source, the process comprising the following steps: Step S1, irradiating the chip wafer with laser to separate the chip wafer into a chip and a substrate without loss, and then mixing the chip with a guide solution to form a mixture; Step S2, providing a surface-modified substrate, coating the electrode area on the surface of the substrate with a conductive adhesive, and then coating the mixture on the substrate to align the chip with the substrate; Step S3, thermally curing the substrate to evaporate the guiding solution and cure the conductive adhesive, and after the conductive adhesive is cured, coating the chip with a silicone layer; Step S4, nano-imprinting the surface of the silicone layer through a micro-lens mold to form a micro-lens array structure on the surface of the silicone layer, and after the silicone layer is cured, a mini backlight prototype is obtained; Step S5, optically integrating, mechanically packaging and LCD integrating the mini backlight source prototype to obtain a mini backlight source.

[0006] The step S1 specifically includes: Step S11, separating the chip from the substrate by irradiating the connection between the chip and the substrate with laser; Step S12: prepare a guiding solution, and mix and stir the chip with the guiding solution so that the chip is evenly distributed and suspended in the liquid guiding solution.

[0007] In step S12, the viscosity of the guiding solution is 10-30 mPa·s, the guiding solution includes a solvent and a surfactant, the mass percentage of the surfactant in the guiding solution is 0.1-0.5%, and the rest is a solvent, the solvent includes deionized water and isopropanol, the volume percentage of isopropanol in the solvent is 5-15%, and the rest is deionized water.

[0008] The step S2 specifically includes: Step S21, coating a chemical reagent containing a polar functional group on the surface of the substrate, and curing the chemical reagent, and obtaining a surface-modified substrate after the curing is completed; Step S22, applying the conductive glue to the center of the electrode area on the surface of the substrate by using an automatic glue dispensing device; Step S23, coating the mixture on the substrate, transferring the chip to the substrate, and then vibrating the substrate. The chip moves toward the electrode area under the action of vibration and aligns with the electrode area. After alignment, the conductive glue makes a preliminary connection between the chip and the electrode area.

[0009] In the step S22, the conductive adhesive comprises modified epoxy resin and silver powder, the volume percentage of the silver powder in the conductive adhesive is 30-40%, and the rest is modified epoxy resin, the particle size of the silver powder is 0.5-2um, and the thickness of the conductive adhesive is 5-10um.

[0010] The step S3 specifically includes: Step S31, thermally curing the conductive adhesive, during which the guiding solution is evaporated; Step S32: After the conductive glue is cured, silicone is coated on the surface of the chip by automatic glue dispensing equipment to form a silicone layer on the chip.

[0011] In step S31, the thermal curing is a two-stage curing, the first stage curing temperature is 50-60°C, the time is 5-10 minutes, and the second stage curing temperature is 80-100°C, the time is 5-10 minutes; In step S32, the thickness of the silicone layer is 15-25 um, graphene is provided in the silicone layer, the mass percentage of graphene in the silicone layer is 2.5%-3%, and the rest is silicone.

[0012] The step S4 specifically includes: Step S41, providing a microlens mold having a lens structure corresponding to the chip; Step S42, using a nanoimprinting device to perform hot embossing on the surface of the silicone layer using a microlens mold, so that a lens array structure corresponding to the lens structure is formed on the surface of the silicone layer; Step S43, the silicone layer is thermally cured to form a protective layer, thereby obtaining a prototype of a mini backlight source.

[0013] In the step S41, the size of the lens structure is adapted to the size of the chip; In the step S42, the imprinting pressure is 10-50 MPa, and the imprinting temperature is 80-120° C.; In the step S43, the thermal curing time is 10-30 minutes, and the thermal curing temperature is 80-120°C.

[0014] A mini backlight source is manufactured using the process of the mini backlight source as described above.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention discloses a mini backlight source design and process, which separates the chip from the substrate by laser irradiation of the chip wafer, and transfers the chip by mixing with a guide solution. Under the action of the guide solution and the substrate with a modified surface, the chip transfer speed and accuracy are effectively improved, solving the problem of low mass transfer rate.

[0016] 2. The mini backlight design and process of the present invention can reduce friction and damage during chip transfer by combining a guiding solution with a modified substrate, thereby improving chip positioning accuracy and avoiding inefficiency caused by inaccurate chip positioning or damage.

[0017] 3. The mini backlight design and process of the present invention reduces the dependence on manual operation in the production process through the coordination of the guiding solution and the surface of the chemically modified substrate, making the automated alignment and transfer of the chip more efficient, significantly reducing the production cost, and the self-assembly method without the need for additional technical equipment makes the overall production process simpler.

[0018] 4. The present invention discloses a mini backlight source design and process, which effectively improves the heat dissipation performance and environmental resistance of the chip and prolongs its service life by coating a silicone protective layer on the chip surface and adding graphene. In addition, the high transparency of the silicone layer reduces light scattering, ensures effective light transmission, and further improves the display effect.

[0019] 5. The present invention discloses a mini backlight source design and process. Through the microlens array structure, the light of the chip is effectively collimated, which reduces diffuse reflection and improves the light transmission efficiency. This makes the mini backlight source excellent in terms of brightness and optical uniformity, and provides significant advantages in the field of high-brightness display. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0022] Figure 1 The present invention is a flowchart of a process of producing a mini backlight source. DETAILED DESCRIPTION

[0023] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0025] Embodiment 1: The process of the mini backlight source in this embodiment is suitable for the production and manufacturing of the mini backlight source, and specifically involves the process of transferring the chip from the chip wafer to the substrate.

[0026] See also Figure 1 In this embodiment, a process of a mini backlight source is provided, and the process includes the following steps: Step S1, irradiating the chip wafer with laser to separate the chip wafer into a chip and a substrate without loss, and then mixing the chip with a guide solution to form a mixture; It should be noted that in the manufacture of mini backlight sources, it is usually necessary to obtain chips from chip wafers, and chip wafers are generally composed of chips and substrates.

[0027] Step S1 specifically includes: Step S11, separating the chip from the substrate by irradiating the connection between the chip and the substrate with laser; Step S12: prepare a guiding solution, and mix and stir the chip with the guiding solution so that the chip is evenly distributed and suspended in the liquid guiding solution.

[0028] It should be noted that when the laser is irradiated at the connection between the chip and the substrate, the gallium nitride at the connection absorbs the laser energy and undergoes local thermal expansion, forming a stress-destroying bond, which weakens the adhesion between the chip and the substrate, thereby allowing the chip to be peeled off. At the same time, the mixture formed by mixing the chip with the guide solution can effectively prevent the chip from irregularly aggregating and sticking together due to its surface tension effect and electrostatic adsorption during transfer, resulting in damage to the chip after it is transferred to the substrate for stacking and aggregation.

[0029] In step S11, the wavelength of the laser is 248 nm.

[0030] Specifically, lasers can achieve extremely high light energy density and precise focusing, thereby increasing the separation rate of the chip and substrate, thereby improving the preparation efficiency.

[0031] In step S12, the viscosity of the guiding solution is 10-30 mPa·s, the guiding solution includes a solvent and a surfactant, the mass percentage of the surfactant in the guiding solution is 0.1-0.5%, and the rest is a solvent, the solvent includes deionized water and isopropanol, the volume percentage of isopropanol in the solvent is 5-15%, and the rest is deionized water; preferably, the viscosity of the guiding solution is 20 mPa·s, the mass percentage of the surfactant in the guiding solution is 0.3%, and the rest is a solvent, the solvent includes deionized water and isopropanol, the volume percentage of isopropanol in the solvent is 10%, and the rest is deionized water.

[0032] Specifically, when the chip is subsequently aligned, the guide solution can serve as a buffer medium to reduce friction and collision with the substrate, thereby protecting the chip.

[0033] It should also be noted that by guiding the surface tension and fluidity of the solution, the chip can be quickly aligned on the substrate, thereby improving the alignment efficiency.

[0034] Step S2, providing a surface-modified substrate, coating the electrode area on the surface of the substrate with a conductive adhesive, and then coating the mixture on the substrate to align the chip with the substrate; It should be noted that in the preparation process of miniLED backlight source, the substrate is a key component, which is mainly responsible for supporting and connecting the chip. The substrate is usually made of insulating material, which can provide electrical connection and ensure the stability and heat dissipation performance of the chip. Electrodes and other structures are provided on the substrate.

[0035] Step S2 specifically includes: Step S21, coating a chemical reagent containing a polar functional group on the surface of the substrate, and curing the chemical reagent, and obtaining a surface-modified substrate after the curing is completed; Step S22, applying the conductive glue to the center of the electrode area on the surface of the substrate by using an automatic glue dispensing device; Step S23, coating the mixture on the substrate, transferring the chip to the substrate, and then vibrating the substrate. The chip moves toward the electrode area under the action of vibration and aligns with the electrode area. After alignment, the conductive glue makes a preliminary connection between the chip and the electrode area.

[0036] It should be noted that by treating the surface of the substrate with chemical reagents, the surface energy of the substrate surface can be changed, so that the substrate surface has hydrophilicity and uniform charge distribution, and a surface energy difference is formed between the electrode area and the non-electrode area on the substrate surface. After the mixture in the above step S1 is coated on the surface of the substrate, the substrate can guide the chip to move to the electrode area on the substrate by itself through the surface energy difference on its surface and the cooperation of the guiding solution in the mixture, and adhere to the electrode area with the cooperation of the conductive glue to achieve precise positioning and form an electrical connection; in this way, after the chip falls on the surface of the substrate, it can be automatically positioned with the electrode area, which effectively reduces the time required to position the chip on the substrate surface and improves production efficiency. At the same time, under the action of the conductive glue, the chip can also adhere to the electrode area to achieve precise positioning, providing a stable foundation for the follow-up.

[0037] It should also be noted that before transferring the chip to the substrate, first coating the electrode area of ​​the substrate with conductive glue can allow subsequent chips to be attached when aligned with the electrode area, avoiding random drift of the chip in the guide solution. At the same time, the chip is initially connected to the electrode area through the conductive glue, which can also reduce the occurrence of chip offset displacement due to uncertain factors in subsequent processes.

[0038] In step S22, the conductive adhesive includes modified epoxy resin and silver powder, the volume percentage of silver powder in the conductive adhesive is 30-40%, the rest is modified epoxy resin, the silver powder particle size is 0.5-2um, and the thickness of the conductive adhesive is 5-10um; preferably, the volume percentage of silver powder in the conductive adhesive is 35%, the rest is modified epoxy resin, the silver powder particle size is 0.8um, and the thickness of the conductive adhesive is 7um.

[0039] It should also be noted that the deionized water and isopropyl alcohol in the guide solution are almost immiscible with the epoxy resin in the conductive adhesive. Epoxy resin is a non-polar molecule, and the guide solution is mainly deionized water and isopropyl alcohol. Therefore, the two are incompatible at the physical level. In the uncured conductive adhesive, the chemical inertness of the silver powder also prevents it from reacting with deionized water and isopropyl alcohol. Moreover, due to the high adhesion of the conductive adhesive, the guide solution cannot penetrate or destroy the surface structure of the conductive adhesive, and the conductive adhesive can remain stable throughout the positioning process.

[0040] Specifically, chemical reagents containing polar functional groups include hydroxyl, carboxyl and amine groups; hydroxyl and carboxyl groups can increase the hydrophilicity of the substrate surface, allowing the guide liquid to spread evenly on the substrate surface, and amine groups can introduce electrostatic properties to promote the interaction between the substrate surface and the chip, allowing the chip to achieve self-alignment.

[0041] In a specific embodiment, when chemically modifying the surface of a substrate, a fluorine-containing polymer is coated on the electrode area of ​​the substrate surface to reduce the surface energy of the area, and a chemical reagent containing a polar functional group is used to treat the non-electrode area of ​​the substrate to increase the hydrophilicity of the area, thereby increasing the surface energy of the area. Through the surface energy difference between the electrode area and the non-electrode area and in combination with a guiding solution, the chip can be quickly guided to improve the alignment efficiency of the chip.

[0042] When the chip is transferred to the electrode area on the substrate surface, the actual moving speed of the chip can be detected according to the laser Doppler velocimeter, and then compared with the preset moving speed of the chip. When it is found that the actual moving speed of the chip is less than the preset moving speed of the chip, the surface energy difference of the substrate surface and the viscosity of the guide solution in the subsequent chip transfer work can be adjusted to ensure the mass transfer rate in the subsequent chip transfer work. After it is found that the actual moving speed of the chip meets the preset moving speed of the chip, the surface energy difference of the substrate surface and the viscosity of the guide solution in the subsequent chip transfer work do not need to be adjusted; The adjustment process specifically includes: Step 1: Obtain the actual surface energy difference of the substrate surface according to the actual moving speed of the chip and the function formula; Step 2: Compare the actual surface energy difference of the substrate surface with the preset surface energy difference of the substrate surface. When it is known that the actual surface energy difference of the substrate surface is less than the preset surface energy difference of the substrate surface, it is necessary to increase the surface energy difference of the substrate surface in the subsequent chip transfer work to increase the chip movement speed accordingly. When it is known that the preset surface energy difference of the substrate surface meets the preset surface energy difference of the substrate surface, it means that the viscosity of the guide solution is too high, and it is necessary to reduce the viscosity of the guide solution in the subsequent chip transfer work to increase the chip movement speed accordingly.

[0043] The function formula of the preset moving speed of the chip, the preset surface energy difference of the substrate surface and the preset viscosity of the guiding solution is: ; Where: The preset moving speed of the chip; is the size of the chip; is a preset surface energy difference of the substrate surface; The preset viscosity of the guiding solution; The actual surface energy difference of the substrate surface is: Where: is the actual moving speed of the chip; is the actual surface energy difference of the substrate surface.

[0044] It should be noted that the preset moving speed of the chip in this embodiment can be obtained by simulation analysis using a finite element model. Specifically, a finite element model can be established first according to the chip parameters and processing scenarios. Combined with the target's mass transfer rate, the preset moving speed can be obtained. The finite element model is used for simulation analysis by methods such as dynamic analysis, nonlinear static analysis, and linear static analysis. The specific analysis process is well known to the technicians of this embodiment and will not be described in this embodiment. The preset viscosity of the guide solution is the optimal value in the above step S12. The function formula is obtained through a linear regression model. Through this formula, after determining the preset moving speed of the chip and the preset viscosity of the guide solution, the preset surface energy difference of the substrate surface can also be obtained.

[0045] It can be known that the actual moving speed of the chip can be measured by the staff through a laser Doppler velocimeter before the formal preparation of the mini backlight source, so as to optimize the moving speed of the chip and the viscosity of the guide solution when the mini backlight source is formally prepared; the size of the chip can be set in advance, and the finite element model and the linear regression model are well known to the technicians in this embodiment and will not be explained in this embodiment.

[0046] It can be understood that the mass transfer rate is the efficiency of transferring chips from a carrier (such as a chip wafer) to a target substrate within a specific time frame. In the manufacture of mini backlight sources, the mass transfer rate directly reflects the production efficiency. The faster the chip moves, the higher the mass transfer rate.

[0047] Specifically, the surface energy of the non-electrode area of ​​the substrate is increased by increasing the concentration of a chemical reagent containing a polar functional group to treat the non-electrode area of ​​the substrate, and the surface energy of the electrode area of ​​the substrate is reduced by increasing the concentration of a fluorine-containing polymer to treat the electrode area of ​​the substrate, thereby improving the surface difference of the substrate surface; For example, when the surface difference of the substrate surface is 10mN / m, 20mN / m, 30mN / m..., the non-electrode area of ​​the substrate is 35mN / m, 40mN / m, 45mN / m..., and the electrode area of ​​the substrate is 25mN / m, 20mN / m, 15mN / m...; Correspondingly, the percentage increases of the concentrations of the chemical reagents containing polar functional groups were 0.1%, 0.2%, and 0.3%, and the percentage increases of the concentrations of the fluoropolymers were 0.5%, 1%, and 1.5%, respectively; In addition, by reducing the mass percentage of isopropyl alcohol in the guiding solution, the guiding solution viscosity can be reduced; For example, when the chip moving speed is 1mm / s, 3mm / s, 5mm / s, ..., the viscosity of the guide solution is 30mPa·s, 20mPa·s, 10mPa·s, ..., and the corresponding mass percentage of isopropyl alcohol in the guide solution is 10%, 8%, 6%, ..., respectively.

[0048] Therefore, when the actual moving speed of the chip is lower than the preset moving speed of the chip, the actual moving speed of the chip in the subsequent chip transfer work can be made to match the preset moving speed of the chip by increasing the surface energy difference of the substrate surface or reducing the viscosity of the guide solution, and instructions can be provided for the chemical modification of the substrate surface and the preparation of the guide solution in the subsequent chip transfer work, thereby ensuring the mass transfer rate.

[0049] Specifically, the vibration frequency range of the sonic vibrator is 30-60kHz, and the sonic vibration power is 100-150mW / cm².

[0050] At the same time, when the chip is aligned, the substrate is vibrated by the acoustic wave vibrator, and the acoustic wave is transmitted through the substrate to the guide solution to form an acoustic pressure gradient. The chip is driven by the pressure difference under the action of the acoustic wave, which can increase the movement speed of the chip. The surface energy difference between the electrode area and the non-electrode area and the pressure difference caused by the acoustic wave can further improve the chip alignment efficiency, thereby increasing the mass transfer rate.

[0051] Step S3, thermally curing the substrate to evaporate the guiding solution and cure the conductive adhesive, and after the conductive adhesive is cured, coating the chip with a silicone layer; Step S3 specifically includes: Step S31, thermally curing the conductive adhesive, during which the guiding solution is evaporated; Step S32: After the conductive glue is cured, silicone is coated on the surface of the chip by automatic glue dispensing equipment to form a silicone layer on the chip.

[0052] In step S31, the thermal curing is a two-stage curing, the first stage curing temperature is 50-60°C, the time is 5-10 minutes, and the second stage curing temperature is 80-100°C, the time is 5-10 minutes; Preferably, the first stage curing temperature is 55° C. and the time is 10 min, and the second stage curing temperature is 90° C. and the time is 5 min.

[0053] It should be noted that by thermally curing the coated conductive adhesive, a stable electrical connection and mechanical support can be provided for the electrode area on the chip and the substrate. At the same time, through subsequent silicone coating, a silicone layer with a protective function can be formed on the chip surface, thereby improving the chip's resistance to environmental influences and improving heat dissipation performance and optical effects.

[0054] It should also be noted that after the conductive adhesive is cured, it can be gradually transformed from a liquid state into a polymer solid structure, thereby locking the conductive particles in the electrode area on the surface of the substrate to form a stable conductive path. By curing the conductive adhesive in sections, the internal stress in the conductive adhesive can be gradually released, thereby reducing the risk of chip position deviation during the curing process. At the same time, during the curing process of the conductive adhesive, the guide solution can also be evaporated and removed simultaneously, thereby simplifying the process and improving work efficiency.

[0055] In step S32, the thickness of the silicone layer is 15-25um, graphene is provided in the silicone layer, the mass percentage of graphene in the silicone layer is 2.5%-3%, and the rest is silicone; preferably, the thickness of the silicone layer is 20um, the mass percentage of graphene in the silicone layer is 2%, and the rest is silicone.

[0056] It can be understood that the silicone layer forms a flexible protective film on the chip, which effectively isolates it from external moisture, dust and pollutants. At the same time, under the action of graphene in the silicone layer, it can also efficiently guide the heat generated by the chip in subsequent work to diffuse outward, thereby reducing the operating temperature of the chip and extending its service life.

[0057] In addition, the high transparency of silicone can reduce the scattering and absorption of light, ensuring that the light emitted by the chip can be efficiently transmitted to the outside world.

[0058] Step S4, nano-imprinting the surface of the silicone layer through a micro-lens mold to form a micro-lens array structure on the surface of the silicone layer, and after the silicone layer is cured, a mini backlight prototype is obtained; Step S4 specifically includes: Step S41, providing a microlens mold having a lens structure corresponding to the chip; Step S42, using a nanoimprinting device to perform hot embossing on the surface of the silicone layer using a microlens mold, so that a lens array structure corresponding to the lens structure is formed on the surface of the silicone layer; Step S43, the silicone layer is thermally cured to form a protective layer, thereby obtaining a prototype of a mini backlight source.

[0059] It should be noted that by embossing a lens array structure on the silicone layer through a microlens mold, the scattering and reflection of light emitted by the chip can be effectively reduced, thereby improving the light transmission efficiency. At the same time, the microlens array structure can also convert the light emitted by the chip from a divergent state to a collimated state, reducing light loss. In addition, by embossing, a microlens array structure can be set on a large area of ​​the chip at one time, thereby reducing production costs and improving work efficiency.

[0060] It can be understood that the microlens array changes the propagation path of the light emitted by the chip, shapes the scattered light emitted by the chip into a collimated beam, reduces diffuse reflection and light loss, and changes in this way can significantly improve the chip's luminous efficiency and light energy utilization, while improving the uniformity of light distribution and making the brightness of the entire backlight source consistent.

[0061] In step S41, the size of the lens structure is adapted to the size of the chip; In step S42, the imprinting pressure is 10-50 MPa and the imprinting temperature is 80-120°C; preferably, the imprinting pressure is 30 MPa and the imprinting temperature is 100°C. In step S43, the thermal curing time is 10-30 minutes, and the thermal curing temperature is 80-120°C; preferably, the thermal curing time is 20 minutes, and the thermal curing temperature is 100°C.

[0062] Step S5, optically integrating, mechanically packaging and LCD integrating the mini backlight source prototype to obtain a mini backlight source.

[0063] It should be noted that, with the cooperation of the above-mentioned steps S1 to S5, the chip is quickly and non-destructively peeled off, and the chip self-assembly is achieved with the cooperation of the guiding solution, thereby improving the mass transfer rate and greatly improving the production efficiency. The self-assembled chip can also improve the chip alignment accuracy under the energy difference between the guiding solution and the substrate surface. At the same time, the chip self-assembly does not require additional technical investment and reduces the production cost. Subsequently, the optical performance of the chip is effectively improved by setting the microlens array structure, so that the use effect of the manufactured mini backlight source is improved. Therefore, with the cooperation of the above-mentioned steps S1 to S5, the problem of low mass transfer rate can be solved.

[0064] It should also be added that optical integration of the mini backlight prototype can match the optical efficiency of the microlens array with that of the chip light source, further improving the uniformity and brightness of light emission. After the optical integration is completed, mechanical packaging of the mini backlight prototype can provide good structural support and sealing performance for the mini backlight prototype, protecting the internal chip and optical structure of the mini backlight prototype from the influence of the external environment. After optical integration and mechanical packaging of the mini backlight prototype, LCD integration is performed to achieve seamless connection between the mini backlight prototype and the LCD panel, providing high-quality display effects for the formed mini backlight.

[0065] It is understandable that, in the preparation of the mini backlight source, optical integration, mechanical packaging and LCD integration are well known to those skilled in the art and will not be described in this embodiment.

[0066] Embodiment 2: A mini backlight source in the present embodiment is manufactured by adopting the process of the mini backlight source as described above.

[0067] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for a mini backlight source, characterized in that: The process comprises the following steps: Step S1, irradiating the chip wafer with laser to separate the chip wafer into a chip and a substrate without loss, and then mixing the chip with a guide solution to form a mixture; Step S2, providing a surface-modified substrate, coating the electrode area on the surface of the substrate with a conductive adhesive, and then coating the mixture on the substrate to align the chip with the substrate; Step S3, thermally curing the substrate to evaporate the guiding solution and cure the conductive adhesive, and after the conductive adhesive is cured, coating the chip with a silicone layer; Step S4, nano-imprinting the surface of the silicone layer through a micro-lens mold to form a micro-lens array structure on the surface of the silicone layer, and after the silicone layer is cured, a mini backlight prototype is obtained; Step S5, optically integrating, mechanically packaging and LCD integrating the mini backlight source prototype to obtain a mini backlight source.

2. The process of a mini backlight source according to claim 1, characterized in that: The step S1 specifically includes: Step S11, separating the chip from the substrate by irradiating the connection between the chip and the substrate with laser; Step S12: prepare a guiding solution, and mix and stir the chip with the guiding solution so that the chip is evenly distributed and suspended in the liquid guiding solution.

3. The process of a mini backlight source according to claim 2, characterized in that: In step S12, the viscosity of the guiding solution is 10-30 mPa·s, the guiding solution includes a solvent and a surfactant, the mass percentage of the surfactant in the guiding solution is 0.1-0.5%, and the rest is a solvent, the solvent includes deionized water and isopropanol, the volume percentage of isopropanol in the solvent is 5-15%, and the rest is deionized water.

4. The process of a mini backlight source according to claim 1, characterized in that: The step S2 specifically includes: Step S21, coating a chemical reagent containing a polar functional group on the surface of the substrate, and curing the chemical reagent, and obtaining a surface-modified substrate after the curing is completed; Step S22, applying the conductive glue to the center of the electrode area on the surface of the substrate by using an automatic glue dispensing device; Step S23, coating the mixture on the substrate, transferring the chip to the substrate, and then vibrating the substrate. The chip moves toward the electrode area under the action of vibration and aligns with the electrode area. After alignment, the conductive glue makes a preliminary connection between the chip and the electrode area.

5. The process of a mini backlight source according to claim 4, characterized in that: In the step S22, the conductive adhesive comprises modified epoxy resin and silver powder, the volume percentage of the silver powder in the conductive adhesive is 30-40%, and the rest is modified epoxy resin, the particle size of the silver powder is 0.5-2um, and the thickness of the conductive adhesive is 5-10um.

6. The process of a mini backlight source according to claim 1, characterized in that: The step S3 specifically includes: Step S31, thermally curing the conductive adhesive, during which the guiding solution is evaporated; Step S32: After the conductive glue is cured, silicone is coated on the surface of the chip by automatic glue dispensing equipment to form a silicone layer on the chip.

7. The process of a mini backlight source according to claim 6, characterized in that: In step S31, the thermal curing is a two-stage curing, the first stage curing temperature is 50-60°C, the time is 5-10 minutes, and the second stage curing temperature is 80-100°C, the time is 5-10 minutes; In step S32, the thickness of the silicone layer is 15-25 um, graphene is provided in the silicone layer, the mass percentage of graphene in the silicone layer is 2.5%-3%, and the rest is silicone.

8. The process of a mini backlight source according to claim 1, characterized in that: The step S4 specifically includes: Step S41, providing a microlens mold having a lens structure corresponding to the chip; Step S42, using a nanoimprinting device to perform hot embossing on the surface of the silicone layer using a microlens mold, so that a lens array structure corresponding to the lens structure is formed on the surface of the silicone layer; Step S43, the silicone layer is thermally cured to form a protective layer, thereby obtaining a prototype of a mini backlight source.

9. The process of a mini backlight source according to claim 8, characterized in that: In the step S41, the size of the lens structure is adapted to the size of the chip; In the step S42, the imprinting pressure is 10-50 MPa, and the imprinting temperature is 80-120° C.; In the step S43, the thermal curing time is 10-30 minutes, and the thermal curing temperature is 80-120°C.

10. A mini backlight source, characterized in that: The mini backlight source is manufactured by the process of any one of claims 1 to 9.

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