A light source assembly for Mini LED backlight module and a manufacturing method thereof

Abstract

The present invention relates to a light source assembly for a Mini LED backlight module and a manufacturing method thereof, comprising: arranging a plurality of light-emitting units on the front of a circuit substrate, coating the front of the circuit substrate and the surface of the light-emitting units with at least two layers of anti-reflection films; coating the surface of the anti-reflection films with a metal layer away from the circuit substrate; sputtering substrate molecules on the surface of the metal layer to form a light-shielding layer covering the front of the circuit substrate and the surface of each light-emitting unit; removing the light-shielding layer and the metal layer on the surface of the positive light-emitting surface of the light-emitting unit. The light source assembly of the present invention is suitable for a Mini LED backlight module, and can effectively increase the brightness of the light source, reduce the halo effect, increase the display contrast, and enhance the image quality, while saving costs and reducing energy consumption.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a method for manufacturing a light source assembly for a Mini LED backlight module. Background Art

[0002] As a new type of backlight, Mini LED backlight is widely used in the field of liquid crystal display. Compared with traditional LED backlight sources, it has the characteristics of lightness, high resolution, and low power consumption, and has attracted much attention in recent years. Mini LED is also called sub-millimeter light-emitting diode. Mini LED backlight can achieve regional dimming within a precise range by densely arranging a large number of Mini LED chips, that is, arranging thousands of narrow-pitch light-emitting diodes with a size of several hundred microns. The halo effect is a difficult problem faced by local dimming technology. Traditionally, it is believed that the smaller the halo area, the better. However, in fact, if the halo in the Mini-LED backlight is really made extremely small, a mosaic-like effect will appear in the implementation of regional dimming technology, and the display effect will be reduced. On the contrary, if the halo area is too large, it will greatly affect the high contrast effect of the Mini-LED backlight. Selecting a light source component that matches the Mini LED backlight module plays a vital role in adjusting the halo effect and improving the display effect of Mini LED.

[0003] In the prior art, an opaque black ink layer or a black glue layer (hereinafter collectively referred to as a black deposition layer) is made on a PCB board through processes such as inkjet printing, black glue caulking, and hot lamination to solve the problem that after the Mini LED chip and the package of the Mini LED chip (hereinafter collectively referred to as the light-emitting unit) are soldered to the PCB board through a solder pad, a portion of the solder pad is not covered by the light-emitting unit. During the soldering process, the solder paste used will turn silver after melting and cover the surface of the solder pad. The silver has a reflective property, which causes the display screen to not be black enough when the screen is black, that is, the contrast of the display screen is reduced, affecting the display effect. The prior art black glue layer, black inkjet and other manufacturing technologies, such as Figure 1 As shown, the thickness of the black glue layer at A, B, and C is different, which easily leads to uneven display and mottled effect.

[0004] Prior art CN114975394A discloses an LED light source assembly and a manufacturing method thereof, and an LED display screen, wherein molecules of a black substrate are sputtered and deposited onto the front of a circuit substrate and the surface of each light-emitting unit to form a black deposition layer; the process is no longer limited by the flatness of the area to be formed with the black deposition layer, so that the area to be deposited with black is 100% covered, and the formed black deposition layer is uniform, which can reduce the black chromaticity difference at various positions of the shading layer, thereby improving the contrast of a display screen made using the LED light source assembly, and avoiding the occurrence of mottled light at a side viewing angle of the display screen, thereby solving the problem that the manufacturing process of the black layer on the PCB board in the existing display screen is limited by flatness, the uniformity and consistency of the shading layer obtained are poor, and dead angles are easily covered, resulting in poor contrast and display effect of the display screen; at the same time, the sputtering process has low production control difficulty and high yield, which can reduce production costs.

[0005] The dimming accuracy of the light source components in the Mini LED backlight module is higher than that of the traditional LED. As the pixel pitch decreases in the Mini LED backlight module, the proportion of the display area occupied by the light-emitting unit becomes larger and larger. The pad size of the electrode on the PCB board used to solder the light-emitting unit must match the size of the Mini LED chip, and the shading layer must be evenly covered to improve the contrast of the display screen, which plays a significant role in improving the display effect of the Mini LED. Therefore, in the application of the Mini LED backlight module, there are higher technical requirements for the manufacturing accuracy of the light source components. Summary of the invention

[0006] The present invention provides a light source assembly for a Mini LED backlight module, aiming to provide a method for manufacturing a light-shielding layer on a PCB board suitable for the Mini LED backlight module, wherein the light-shielding layer includes but is not limited to a black deposition layer, and the flatness, uniformity and consistency of the light-shielding layer on the prepared PCB board are better than those in the prior art, thereby avoiding coverage of dead corners, and the side surfaces of the light-emitting units in the prepared light source assembly for the Mini LED backlight module can be completely covered by the light-shielding layer to provide a light source with sufficient brightness and uniform distribution, thereby solving the problems of insufficient brightness, uneven distribution and excessive power consumption of the light source assembly in the prior art.

[0007] The present invention provides a light source assembly for a Mini LED backlight module and a manufacturing method thereof, wherein the structure of the light source assembly includes: a circuit substrate, a light emitting unit, a reflection enhancement film layer, a metal layer, and a light shielding layer;

[0008] A plurality of light-emitting units arranged on the front side of the circuit substrate;

[0009] A reflection-enhancing film layer is plated on the front surface of the circuit substrate and the surface of the light-emitting unit;

[0010] Plating a metal layer on the surface of the anti-reflection film in a direction away from the circuit substrate;

[0011] A light shielding layer is plated on the surface of the metal layer to form a light shielding layer covering the front surface of the circuit substrate and the surface of each light emitting unit;

[0012] The light shielding layer, the metal layer and the anti-reflection film layer on the front light emitting surface of the light emitting unit are removed, and the front light emitting surface of the light emitting unit is a surface of the light emitting unit away from the circuit substrate and parallel to the circuit substrate;

[0013] At least a part of the positive light emitting surface of the light emitting unit after at least a part of the light shielding layer and the metal layer are removed is in a light-transmitting state.

[0014] Furthermore, the anti-reflection film comprises at least one high-refractive index film layer and at least one low-refractive index film layer, and at least one high-refractive index film layer and one low-refractive index film layer in the anti-reflection film are in contact with and overlapped with each other.

[0015] Furthermore, the total thickness of the anti-reflection film layer is 100-600 nm.

[0016] Furthermore, the material of the metal layer is selected from silver, aluminum, zinc or any combination thereof.

[0017] Furthermore, the total thickness of the metal layer is 10-200 nm.

[0018] Furthermore, the substrate is selected from at least one of oxides, silicides and nitrides.

[0019] Furthermore, the light shielding layer may be, but is not limited to, a black deposition layer.

[0020] Furthermore, the state of removing the light shielding layer, the metal layer and the anti-reflection film layer on the front light emitting surface of the light emitting unit is:

[0021] The light shielding layer, the metal layer and the anti-reflection film layer on the front light emitting surface of the light emitting unit are all removed;

[0022] or

[0023] The light shielding layer and the metal layer on the front light emitting surface of the light emitting unit are completely removed, and the anti-reflection film layer is partially removed;

[0024] or

[0025] The light shielding layer and the metal layer on the front light emitting surface of the light emitting unit are completely removed.

[0026] A method for manufacturing a light source assembly for a Mini LED backlight module, characterized in that:

[0027] A plurality of light-emitting units are arranged on the front side of the circuit substrate;

[0028] A reflection-enhancing film layer is plated on the front surface of the circuit substrate and the surface of the light-emitting unit;

[0029] Plating a metal layer on the surface of the anti-reflection film in a direction away from the circuit substrate;

[0030] Sputtering black substrate molecules on the surface of the metal layer to form a light shielding layer covering the front surface of the circuit substrate and the surface of each light-emitting unit;

[0031] The light shielding layer, the metal layer and the anti-reflection film layer on the front light-emitting surface of the light-emitting unit are removed, and the front light-emitting surface of the light-emitting unit is a surface of the light-emitting unit away from the circuit substrate and parallel to the circuit substrate;

[0032] At least a part of the positive light emitting surface of the light emitting unit after at least a part of the light shielding layer and the metal layer are removed is in a light-transmitting state.

[0033] Furthermore, an anti-reflection film layer is plated on the front surface of the circuit substrate and the surface of the light-emitting unit, and the plating method includes: a combination of one or more methods selected from magnetron sputtering, vacuum evaporation, vacuum sputtering and arc ion plating.

[0034] Furthermore, a metal layer is plated on the surface of the anti-reflection film in a direction away from the circuit substrate.

[0035] The coating methods include: one or more combinations of magnetron sputtering, vacuum evaporation, vacuum sputtering and arc ion plating.

[0036] Furthermore, the substrate molecules are sputtered onto the surface of the metal layer by a magnetron sputtering method.

[0037] Furthermore, at least a portion of the light shielding layer and the metal layer is removed, and the removal method includes: a combination of one or more methods of laser etching, grinding, and plasma etching.

[0038] The light source component suitable for the Mini LED backlight module provided in the present invention has a simple manufacturing process, and the anti-reflection film layer, the metal layer and the shading layer are plated on the front side of the circuit substrate and the surface of the light-emitting unit, and the shading layer and the metal layer on the light-emitting front surface are partially removed, so that the light source component can be used without additional packaging. Since the light-emitting unit required for the Mini LED backlight module is a micron-level chip, the mixed light distance has a great influence on the halo effect. Therefore, the anti-reflection film layer, the metal layer and the shading layer are plated on the basic front surface of the circuit of the present invention to protect the circuit substrate and each light-emitting unit. Each light-emitting unit directly transmits light to the backlight module through the anti-reflection film on the surface, thereby reducing interference with the mixed light distance, ensuring the light output efficiency of each light-emitting unit, and facilitating precise adjustment of the light output range of the Mini LED backlight module.

[0039] In the present invention, the anti-reflection film is plated on the front side of the circuit substrate and the surface of each light-emitting unit. The anti-reflection film can reflect specific wavelengths, and the ideal anti-reflection effect can be obtained by the number of film layers of the anti-reflection film. The metal layer on the anti-reflection film acts as a reflector. The combination of the anti-reflection film on the side of each light-emitting unit and the metal film as a reflector can reduce the light loss of the light-emitting unit, increase the brightness of the light-emitting unit, and improve the display effect of the Mini LED backlight module. At the same time, the anti-reflection film effectively improves the polarization degree of the emitted light and enhances the intensity of the emitted light of the light-emitting unit, thereby reducing power consumption and reducing costs.

[0040] The metal layer deposited on the surface of the anti-reflection film of the present invention acts as a reflector. The metal layer reflects side light and the barrier effect of the metal layer prevents the shading layer on the side of the light-emitting unit from absorbing light, thereby increasing the luminous flux, reducing the temperature of the light source component, and reducing the problem of unstable luminous performance of the light source component due to temperature rise. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. 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 the contents and drawings of the embodiments of the present invention without paying any creative work.

[0042] In addition, for the convenience of understanding, the size ratios of the components in the drawings described below are adjusted accordingly.

[0043] Figure 1 It is a schematic cross-sectional view of a black layer formed by inkjet printing and black glue filling in the prior art;

[0044] Figure 2 It is the implementation step of the scheme of the present invention;

[0045] Figure 3is a cross-sectional view of the arrangement of the light-emitting units on the circuit substrate in the solution of the present invention;

[0046] Figure 4 It is a schematic diagram of the structure of the light source assembly of the present invention after coating various film layers;

[0047] Figure 5 It is a schematic diagram of removing the black layer, anti-reflection film, metal layer and light-shielding layer along the position of the light-emitting unit.

[0048] In the figure: circuit substrate 101, light emitting unit 102, black layer 103, anti-reflection film 104, metal layer 105, light shielding layer 106 DETAILED DESCRIPTION

[0049] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the process equipment or devices not specifically noted in the following embodiments all adopt conventional equipment or devices in the art. In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the presence of other method steps before and after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; it should also be understood that the combined connection relationship between one or more devices / devices mentioned in the present invention does not exclude the presence of other devices / devices before and after the combination device / device or the insertion of other devices / devices between these explicitly mentioned two devices / devices, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, rather than limiting the order of arrangement of each method step or limiting the scope of the present invention. The change or adjustment of its relative relationship, without substantial change in the technical content, should also be regarded as the scope of the present invention. For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0051] This embodiment provides a method for manufacturing a light source assembly suitable for a Mini LED backlight module, which includes but is not limited to:

[0052] S201: Arrange a plurality of light-emitting units on the front side of the circuit substrate;

[0053] In the embodiment, a plurality of pads for electrically connecting to the electrodes of the light-emitting unit are provided on the front of the circuit substrate, and the distribution of each pad can be in a matrix distribution; of course, it can also be set to other distribution modes according to the needs, and this embodiment does not impose specific restrictions on it. In some examples of this embodiment, the material of the pad can be but not limited to silver, aluminum, zinc, etc. In this embodiment, the pad on the front of the circuit substrate can be used for but not limited to electrically connecting to the electrodes of the light-emitting unit, and the electrodes of the light-emitting unit can be electrically connected to the corresponding pads through but not limited to solder and conductive glue. The light-emitting unit in this embodiment can be but not limited to a MiniLED chip package. In this embodiment, the LED chip can include at least one of a Mini LED chip, a Micro LED chip, and an ordinary LED chip with a size larger than that of a Mini LED chip in terms of size classification; preferably, in terms of the distribution mode of the LED chip electrode, it can include at least one of a flip-chip LED chip, a front-mounted LED chip, and a vertical LED chip; when the light-emitting unit is an LED chip, it can be preferably a flip-chip LED chip. Of course, it should also be understood that the LED light source assembly in this embodiment is not limited to the display field.

[0054] In this embodiment, the side opposite to the front side of the circuit substrate is the back side of the circuit substrate; it should be understood that the front side and the back side of the circuit substrate in this embodiment are relative. It should also be understood that the circuit substrate in this embodiment can be made of a variety of materials, which can be rigid materials, such as but not limited to phenolic paper laminates, polyester glass felt laminates, epoxy paper laminates, epoxy glass cloth laminates, BT resin boards, and glass plates yin; the circuit substrate in this embodiment can also be made of flexible materials, such as but not limited to polyester films, polyimide films, and fluorinated ethylene propylene films. In some examples, corresponding circuits and corresponding welding methods can be integrated in or on the surface of the circuit substrate according to application requirements, such as but not limited to circuits connected to light-emitting units and driving circuits.

[0055] In an application scenario of the present embodiment, a luminous pixel unit may be provided with at least two luminous units, and the number, size, and luminous color of the luminous units included in each luminous pixel unit may be the same, or different, or partly the same and partly different, and may be flexibly set according to the specific application scenario. For example, in some examples, the luminous pixel unit may include three luminous units that emit red light, blue light, and green light, respectively, which are a red light emitting unit, a green light emitting unit, and a blue light emitting unit arranged in sequence. In other examples, in addition to the red light emitting unit, the green light emitting unit, and the blue light emitting unit, the luminous pixel unit may also include a white light emitting unit. It should be understood that the specific arrangement of the luminous units in the luminous pixel unit in the present embodiment may be a herringbone arrangement, a linear arrangement, a center-symmetrical arrangement, etc., and the present embodiment does not limit it.

[0056] S202: coating the front surface of the circuit substrate and the surface of the light-emitting unit with at least two layers of anti-reflection films;

[0057] The anti-reflection film is a multilayer film system formed by alternately coating high-refractive index and low-refractive index materials according to the designed thickness. TiO2 and SiO2 can be selected but not limited to be used as the high-refractive index material and low-refractive index material for preparing the anti-reflection film respectively.

[0058] The anti-reflection film can be prepared by precipitation processes such as bipolar sputtering, triode sputtering, reactive sputtering, magnetron sputtering, dual ion beam sputtering, plasma chemical vapor deposition, and evaporation. The deposition preparation process of the anti-reflection film has been mature and widely used in the prior art, and has now become a conventional manufacturing technology. The anti-reflection film is deposited on the front of the circuit substrate and the surface of the light-emitting unit. The production process is mature and the thickness of the anti-reflection film is easy to control. By adjusting the thickness of the anti-reflection film, in some embodiments, the calculation methods of the optical thin film mainly include graphical method, recursive method, matrix method, etc. With the help of mature mathematical models in this field, the calculation problem of the multi-layer anti-reflection film is easy to obtain.

[0059] In some preferred embodiments, a binary film system with TiO2 as a high refractive index material and SiO2 as a low refractive index material is prepared by magnetron sputtering. The TiO2 and SiO2 anti-reflection films prepared by magnetron sputtering have a series of advantages such as good bonding, uniform thickness, compact film structure, good uniformity, and high mechanical strength. The anti-reflection film deposited by magnetron sputtering is easy to control the thickness, and is suitable for nano-level high-precision coating of Mini LED light source components. Since the anti-reflection film deposited on the front of the circuit substrate and the surface of the light-emitting unit has high requirements for coating uniformity, thickness, bonding force, etc., it is found in experiments and production that there are many factors affecting magnetron sputtering, and various factors directly or interactively affect the characteristics of the film. According to experiments and production, the influence of various factors on the deposited anti-reflection film in the magnetron sputtering process is explored, thereby realizing the control of the film composition, structure and other properties, and providing a basis for depositing the anti-reflection film. The main factors that affect the effect of depositing the anti-reflection film are sputtering power, sputtering pressure, substrate temperature, gas flow rate, and target-substrate distance.

[0060] Example 1:

[0061] The magnetron sputtering equipment was set to have a sputtering power of 80 W, an argon flow rate of 15 sccm, an oxygen flow rate of 8 sccm, a sputtering pressure of 2.0 Pa, a target-substrate distance of 60 cm, and a vacuum degree of 4 × 10 -1 Pa or above, a TiO2 single-layer film and a SiO2 single-layer film, or a multilayer structure of a TiO2 film and a SiO2 film are prepared in sequence.

[0062] Example 2:

[0063] The magnetron sputtering equipment was set to have a sputtering power of 70 W, an argon flow rate of 15 sccm, an oxygen flow rate of 10 sccm, a sputtering pressure of 2.0 Pa, a target-substrate distance of 75 cm, and a vacuum degree of 4 × 10 -1 Pa or above, a TiO2 single-layer film and a SiO2 single-layer film, or a multilayer structure of a TiO2 film and a SiO2 film are prepared in sequence.

[0064] After the anti-reflection film is deposited according to the parameters of Example 1, the reflectivity of the front side of the circuit substrate and the surface of the light-emitting unit after coating is measured by an ellipsometer, which increases by no less than three times compared with before coating, and the peak reflectivity reaches 85%; after the anti-reflection film is deposited according to the parameters of Example 2, the reflectivity of the front side of the circuit substrate and the surface of the light-emitting unit after coating is measured by an ellipsometer, which increases by about four times compared with before coating, and the peak reflectivity reaches 90%.

[0065] In summary, the expected effect can be achieved by depositing an anti-reflection film according to the parameters provided in the above two examples.

[0066] The total thickness of the anti-reflection film is in the range of 100-600 nm.

[0067] S203: plating a metal layer on the surface of the anti-reflection film in a direction away from the circuit substrate;

[0068] A metal layer is plated on the surface of the anti-reflection film in the direction away from the circuit substrate. The metal layer can play the role of a reflector. At the same time, there is an anti-reflection film between the circuit substrate and the metal layer. The anti-reflection film can play an insulating role to prevent the metal layer from directly contacting the solder joints on the circuit substrate to cause circuit short circuits and other problems. The metal layer can achieve good heat dissipation and anti-electromagnetic interference functions, has good reflection and light-enhancing effects, and is used to reflect the light reflected by the anti-reflection film on the light-emitting unit to the light-emitting direction of the light-emitting unit perpendicular to the horizontal line of the light-emitting unit, which plays a good role in brightening the LED and solving the halo effect.

[0069] The material of the metal coating layer is selected from silver, aluminum, zinc or any combination thereof, or other metals or metal alloys.

[0070] The metal layer may be plated by, but is not limited to, magnetron sputtering, vacuum evaporation plating, and the like.

[0071] Example 1:

[0072] The circuit substrate with the light-emitting unit coated with the anti-reflection film was placed in the magnetron sputtering chamber. Under the inert gas environment, the vacuum degree was reduced to 3×10 -1 Pa, the metal target is guided by magnetic field to increase the reflection

[0073] A metal coating is deposited on the surface of the film away from the circuit substrate. The metal substrate is made of a metal with strong reflectivity, which acts as a reflector on the surface of the anti-reflection film.

[0074] Example 2:

[0075] The circuit substrate with the light-emitting unit coated with the anti-reflection film is placed in a vacuum chamber, and the metal to be formed into a thin film, such as silver, in the evaporation container is heated to cause its atoms or molecules to vaporize and escape from the surface to form a vapor flow, which is incident on the surface of the circuit substrate and the light-emitting unit, and condenses to form a metallic silver film.

[0076] 0 or more, in the preparation of light source components suitable for Mini LED backlight modules, magnetron sputtering is preferred

[0077] The metal layer is prepared in this way, and the thickness of the deposited metal layer is between 10-200nm.

[0078] S204: sputtering black substrate molecules on the surface of the metal layer to form a light shielding layer covering the front surface of the circuit substrate and the surface of each light-emitting unit;

[0079] Example 1:

[0080] 5 In a vacuum magnetic environment, a magnetic field is used to guide ions to bombard a black substrate.

[0081] The molecules of the material are uniformly sputtered onto the front surface of the circuit substrate and the surface of each light-emitting unit, thereby depositing to form a light-shielding layer.

[0082] Example 2:

[0083] In a vacuum magnetic environment, the magnetic field is used to guide ions to bombard at least two black substrates at the same time, and the molecules of at least two black substrates are evenly sputtered onto the front of the circuit substrate and the surface of each light-emitting unit.

[0084] In this example, at least two black substrates are bombarded at the same time, so the molecules of the at least two black substrates can be sputtered to the area where the light shielding layer is required to be formed, and deposited to form a black layer including a mixture of multiple molecules. Of course, it should be understood that this example is not limited to the two black substrates.

[0085] The molecules of the black substrate are sputtered and deposited to form a black layer. The molecules of three or more black substrates can also be sputtered and deposited to form a black layer according to needs, which will not be described in detail in this example.

[0086] Example 3:

[0087] In a vacuum magnetic environment, the magnetic field is used to guide ions to bombard at least two black substrates in sequence, and the molecules of at least two black substrates are uniformly sputtered on the front of the circuit substrate and the surface of each light-emitting unit in sequence, thereby depositing and forming a light-shielding layer. In this example, at least two black substrates are bombarded in sequence, so that the molecules of the at least two black substrates can be sputtered in sequence to the area where the light-shielding layer needs to be formed, and deposited to form

[0088] The black layer includes a plurality of molecules. It can be deposited in multiple times. In this example, the first black substrate is deposited, and the black substrate molecules are evenly sputtered on the front of the circuit substrate and the surface of each light-emitting unit to form a black layer.

[0089] After the first molecular layer is formed, a second deposition is performed on the surface of the first molecular layer in a direction away from the front surface of the circuit substrate. The second deposition is performed by using a magnetic field to guide ions to bombard the second black substrate, and the second black substrate is evenly sputtered on the first molecular layer, that is, on the front surface of the circuit substrate and the surface of the light-emitting unit.

[0090] A uniform second molecular layer is formed on the first molecular layer; and a third black molecular layer is deposited in the same manner. Of course, it should be understood that this example is not limited to sequentially depositing the molecules of the three black substrates.

[0091] The black layer is formed by sputtering and deposition. The molecules of two or more black substrates can be sputtered and deposited in sequence to form a black layer as needed, and the above molecular sublayers in this example can also be arranged in an alternating manner. In addition, the replacement of different target materials in this example can be adopted but not limited to manual replacement, or automatic replacement of equipment.

[0092] 5 According to the above examples, the sputtering process in this embodiment can be adopted but is not limited to magnetron sputtering.

[0093] The shading layer in this embodiment can be formed by depositing one type of molecule, or by depositing two or more types of molecules in layers or by mixing and trading them. Therefore, the shading layer can be formed according to the specific application.

[0094] The light shielding layer can be flexibly set according to the scene's requirements for the light transmittance and blackness of the light shielding layer. In particular, the light shielding layer in the above-mentioned examples 2 and 3 includes at least two molecules, so the light shielding layer can be flexibly set according to the scene's requirements for the light transmittance and blackness of the light shielding layer.

[0095] The blackness and transmittance of the layer are adjusted to meet application requirements to ensure contrast while improving display effects.

[0096] At the same time, it should be understood that the present embodiment is not limited to the magnetron sputtering process, and other sputtering processes that can realize the light shielding layer can also be used as equivalent replacements, and the present embodiment does not impose any restrictions on it.

[0097] 5 The black substrate in this embodiment can be flexibly selected. For example, in some examples, this embodiment

[0098] The black substrate in the example may include but is not limited to at least one of oxides, silicides, nitrides and composites. The composite in this embodiment may be but is not limited to a composite of at least two of oxides, silicides and nitrides. For example, in some application scenarios, at least one of but not limited to AZO substrates, SiO2 substrates, SiO substrates, SiC substrates, Si3N4 substrates, or composite substrates of at least two of the above substrates may be used, and the oxide substrates, silicide substrates, nitride substrates and composite substrates in the above examples in this embodiment are all existing conventional materials with low cost and good versatility.

[0099] The thickness of the light shielding layer produced in this embodiment can also be flexibly set according to the light transmittance and blackness requirements of the light shielding layer. For example, in some application examples, the thickness of the formed light shielding layer is greater than or equal to 10 nanometers and less than or equal to 400 nanometers. It can be seen that the light shielding layer in this example is an ultra-thin layer, so it will not increase the overall thickness of the Mini LED light source assembly by a large amount, which is conducive to the ultra-thinness of the Mini LED light source assembly.

[0100] S205: removing the shading layer and the metal layer on the front light-emitting surface of the light-emitting unit. Optionally, removing the shading layer, the metal layer and the anti-reflection film layer on the front light-emitting surface of the light-emitting unit. This step can be referred to in the attached Figure 5 shown. Figure 5 In the figure, the upper figure is the intermediate workpiece of step S204, and the lower figure is the finished workpiece after removal.

[0101] In this embodiment, after forming the above-mentioned shading layer, the shading layer and the metal layer on the front light-emitting surface of each light-emitting unit are completely removed, so as to ensure the light output efficiency of each light-emitting unit through its front light-emitting surface. It should be understood that in this embodiment, whether the anti-reflection film layer on the front light-emitting surface of the light-emitting unit is completely removed, or only a part is removed, and when a part is removed, the specific amount of removal can be dynamically adjusted according to the needs of the specific application scenario, and the Mini LED light output angle is measured, and the refractive degree required for the best light output efficiency is calculated to determine the removal part of the anti-reflection film. This embodiment does not impose specific restrictions on it.

[0102] The present invention provides the following specific embodiments:

[0103] Example 1

[0104] S301: Prepare a circuit substrate; the circuit substrate is made of flexible polyimide film, and the polyimide film substrate is ultrasonically cleaned in acetone, anhydrous ethanol, and deionized water for 10 minutes each, and then dried. After pre-treatment, a corresponding circuit is set on the front of the circuit substrate according to actual application requirements, and a number of pads for connecting to the electrode points of the light-emitting unit are set. The pads are distributed in a matrix on the front of the circuit substrate, and the material of the pads is metallic copper.

[0105] S302: Arrange a plurality of light-emitting units on the front side of the circuit substrate; weld the electrodes of the light-emitting units on the pads by means of conductive adhesive, wherein the light-emitting units are packages of Mini LED chips, and the Mini LED chips are installed and distributed in an upright state.

[0106] S303: Depositing an anti-reflection film on the front surface of the circuit substrate and the surface of the light-emitting unit in S302; the anti-reflection film is composed of alternating high-refractive index materials and low-refractive index materials.

[0107] The high refractive index material uses Ti as the target material and is deposited by magnetron sputtering. The parameters of the vacuum coating equipment are set as follows: the sputtering power of the magnetron sputtering equipment is set to 120w, the argon flow rate is 15sccm, the oxygen flow rate is 10sccm, the sputtering pressure is 2.0Pa, the target-substrate distance is 70cm, and the vacuum degree is 4×10 -1Pa, a magnetic field is introduced on the target cathode surface, and the magnetic field is used to confine charged particles to induce argon ions to bombard the target surface, sputtering TiO2 material to deposit and form a TiO2 film.

[0108] The low refractive index material uses Si as the target material and is deposited by magnetron sputtering. The parameters of the vacuum coating equipment are set as follows: the sputtering power of the magnetron sputtering equipment is set to 80w, the argon flow rate is 15sccm, the oxygen flow rate is 8sccm, the sputtering pressure is 2.0Pa, the target substrate distance is 60cm, and the vacuum degree is 4×10 -1 Pa, a magnetic field is introduced on the target cathode surface, and the magnetic field is used to confine charged particles to induce argon ions to bombard the target surface, sputtering SiO2 material to deposit and form a SiO2 film.

[0109] The TiO2 film and the SiO2 film are stacked in sequence, and the total thickness of the anti-reflection film obtained according to the predicted refractive index is 300nm.

[0110] S304: On the circuit substrate obtained by completing step S303, silver is sputtered on the surface of the anti-reflection film, and the circuit substrate with the light-emitting unit coated with the anti-reflection film is placed in a magnetron sputtering chamber, and the vacuum is set to 4×10 -1 Pa, sputtering current 0.5A, using magnetic field to guide the metal silver target, depositing a metal silver coating on the surface of the anti-reflection film in S303 away from the circuit substrate, the thickness of the metal silver is 100nm.

[0111] S305: Sputtering a light shielding layer, sputtering black substrate molecules on the surface of the metal layer to form a light shielding layer covering the front of the circuit substrate and the surface of each light-emitting unit. The black substrate is SiC and AZO. In a vacuum magnetic environment, the vacuum is set to 4×10 -1 Pa, using the magnetic field to constrain charged particles to induce argon ions to simultaneously bombard the surface of SiC and SiN targets to deposit a light-shielding layer with a transparency of less than 10%. Sputtering 1-3 times according to the transparency of the sputtered coating resulted in a light-shielding layer with a thickness of 150nm.

[0112] S306: Remove the shading layer and the metal layer on the surface of the positive light-emitting surface of the light-emitting unit. According to the total thickness of the sputtered metal layer and the shading layer in S304 and S305, set the parameters of the laser de-plating equipment to remove the shading layer and the metal layer on the positive surface of the light-emitting unit. The laser removal of the metal layer and the shading layer has higher process efficiency and removal accuracy, and the removed shading layer and metal layer powder can be recycled to reduce resource waste.

[0113] An anti-reflection film, a metal layer and a shading layer are formed on the flexible circuit substrate described in the present embodiment. Only the anti-reflection film is left on the positive light-emitting surface of the light-emitting unit on the flexible circuit substrate, and the anti-reflection film, the metal layer and the shading layer are left on the light-emitting surfaces on both sides of the light-emitting unit. The light-emitting unit expands the diffusion angle through multiple reflections of the anti-reflection film, and reflects to the positive direction of the light-emitting unit through the metal layers on both sides of the light-emitting unit, thereby achieving uniform distribution of light and improving the straight-up brightness of the light-emitting unit. The sputtered metal layer has a reflector effect, and no separate reflective sheet is required, which effectively reduces the distance between the Mini LED light source and the backlight module, so that the backlight device is thinned and the light utilization efficiency is improved. The light emitted by the Mini LED light-emitting unit has a light concentration within an adjustable range, which effectively reduces the influence of the halo effect on the color rendering effect of the Mini LED backlight module and eliminates the Mura lamp eye phenomenon.

[0114] Example 2

[0115] S401: Prepare a circuit substrate; the circuit substrate is made of a rigid BT resin board, which is ultrasonically cleaned in acetone, anhydrous ethanol, and deionized water for 10 minutes each, and then dried. After pretreatment, a corresponding circuit is set on the front of the circuit substrate according to actual application requirements, and a number of pads for connecting to the electrode points of the light-emitting unit are set. The pads are distributed in a matrix on the front of the circuit substrate, and the material of the pads is a metal copper-aluminum alloy.

[0116] S402: Arrange a plurality of light-emitting units on the front side of the circuit substrate; weld the electrodes of the light-emitting units on the pads by means of conductive adhesive, wherein the light-emitting units are packages of Mini LED chips, and the Mini LED chips are installed and distributed in an upright state.

[0117] S403: Depositing an anti-reflection film on the front surface of the circuit substrate and the surface of the light-emitting unit in S402; the anti-reflection film is composed of alternating high-refractive index materials and low-refractive index materials.

[0118] The high refractive index material uses Ti as the target material and is deposited by magnetron sputtering. The parameters of the vacuum coating equipment are set as follows: the sputtering power of the magnetron sputtering equipment is set to 100w, the argon flow rate is 12sccm, the oxygen flow rate is 10sccm, the sputtering pressure is 2.0Pa, the target-substrate distance is 75cm, and the vacuum degree is 4×10 -1 Pa, a magnetic field is introduced on the target cathode surface, and the magnetic field is used to confine charged particles to induce argon ions to bombard the target surface, sputtering TiO2 material to deposit and form a TiO2 film.

[0119] The low refractive index material uses Si as the target material and is deposited by magnetron sputtering. The parameters of the vacuum coating equipment are set as follows: the sputtering power of the magnetron sputtering equipment is set to 80w, the argon flow rate is 15sccm, the oxygen flow rate is 8sccm, the sputtering pressure is 2.0Pa, the target substrate distance is 60cm, and the vacuum degree is 4×10 -1 Pa, a magnetic field is introduced on the target cathode surface, and the magnetic field is used to confine charged particles to induce argon ions to bombard the target surface, sputtering SiO2 material to deposit and form a SiO2 film.

[0120] The TiO2 film and the SiO2 film are stacked in sequence, and the total thickness of the anti-reflection film obtained according to the predicted refractive index is 400nm.

[0121] S404: On the circuit substrate obtained by completing step S403, silver is sputtered on the surface of the anti-reflection film, and the circuit substrate with the light-emitting unit coated with the anti-reflection film is placed in a magnetron sputtering chamber, and the vacuum is set to 4×10 -1 Pa, sputtering current 0.5A, using magnetic field to guide the metal silver target, depositing a metal silver coating on the surface of the anti-reflection film in S403 away from the circuit substrate, the thickness of the metal silver is 200nm.

[0122] S405: Sputtering a light shielding layer, sputtering black substrate molecules on the surface of the metal layer to form a light shielding layer covering the front of the circuit substrate and the surface of each light-emitting unit. The black substrate is SiC and SiN. In a vacuum magnetic environment, the vacuum is set to 4×10 -1 Pa, using the magnetic field to constrain charged particles to induce argon ions to bombard the surface of SiC and SiN targets in turn to deposit a light-shielding layer with a transparency of less than 30%. Sputtering 2-4 times according to the transparency of the sputtered coating resulted in a light-shielding layer with a thickness of 150nm.

[0123] S406: remove the shading layer, metal layer and anti-reflection film layer on the surface of the front light-emitting surface of the light-emitting unit. According to the total thickness of the shading layer, metal layer and anti-reflection film layer sputtered in S404 and S405, set the parameters of the laser de-plating equipment, and combine with grinding, plasma etching and other processes to remove the shading layer, metal layer and anti-reflection film layer on the front surface of the light-emitting unit. In this embodiment, all the shading layer, metal layer and anti-reflection film layer on the surface of the front light-emitting surface of the light-emitting unit are removed, combined with grinding, plasma etching and other processes. The process is mature and can save costs.

[0124] Comparative Example

[0125] Prepare to complete steps S401 to S402, as shown in the attached Figure 3The light source assembly shown is light source assembly D1; the light emitting unit with the same parameters as those described in this embodiment is manufactured according to the method of manufacturing a black deposition layer in the prior art is light source assembly B1; and the light source assembly S1 is completed after completing steps S401-S406 described in this embodiment.

[0126] The light source assembly D1, light source assembly B1, and light source assembly S1 are installed in Mini LED backlight modules of the same specifications as TD1, TB2, and TS3, respectively, and temperature cycle tests are performed according to the commonly used industry standards in this field:

[0127] 1. Place T1, T2, and T3 in a test box respectively. The test box can display the temperature change of the bottom of the box, that is, the light source component;

[0128] 2. Connect T1, T2 and T3 to the power supply according to the rated input voltage respectively, and the power switch is set outside the test box;

[0129] 3. Keep the three test chambers at the same room temperature of 25°C;

[0130] 4. When the power is turned on for the first time, the light will continue to glow for 1 minute, recorded as t1; turn off the power, then turn on the power again, the light will continue to glow for 10 minutes, recorded as t2; continue to repeat the above operation, the light will continue to glow for 30 minutes, recorded as t3; the light will continue to glow for 2 hours, recorded as t4, the light will continue to glow for 6 hours, recorded as t5, the light will continue to glow for 12 hours, recorded as t6; the light will continue to glow for 15 hours, recorded as t7. Record the temperature of each time period of continuous lighting.

[0131] temperature TD1 TB2 TS3 t1 25℃ 25℃ 25℃ t2 26.3℃ 26.3℃ 25.8℃ t3 27.1℃ 27.4℃ 26.2℃ t4 31.7℃ 29℃ 26.5℃ t5 40.1℃ 38.7℃ 32℃ t6 47.9℃ 47.2℃ 34.6℃ t7 52.6℃ 51℃ 40.6℃

[0132] (The above test experiment was repeated five times, and the temperature was taken as the average value of the five times)

[0133] Compared with the comparative example, the light source assembly of this embodiment can work continuously for the same working time, especially for more than 6 hours. Compared with the prior art, the temperature of the light source assembly is significantly reduced. Under the same conditions, the luminous efficiency is higher. The light source assembly of the present invention can reduce the light decay effect caused by excessive temperature during operation and has a longer service life.

[0134] In this embodiment, the production process has low difficulty in control and high yield, which can reduce production costs. A reflection-enhancing film, a metal layer and a light-shielding layer are formed on the rigid circuit substrate. All film layers on the front surface of the light-emitting unit on the rigid circuit substrate are removed, and the reflection-enhancing film, the metal layer and the light-shielding layer are still left on the double-side surfaces of the light-emitting unit. The light-shielding layer is not limited by the flatness of the circuit substrate, so that no dead angle coverage is achieved, and the formed light-shielding layer has higher uniformity, avoiding color differences in the light-shielding layer. The light emitted from the light-emitting surface of the light-emitting unit is reflected by the reflection-enhancing film to expand the diffusion angle, and is reflected by the metal layers on both sides of the light-emitting unit to the positive direction of the light-emitting unit, thereby increasing the straight-up brightness of the light-emitting unit and improving the light utilization efficiency. The light-emitting efficiency of each light-emitting unit can be guaranteed, and the display effect of the Mini LED backlight module using the light source component is improved.

[0135] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

Claims

1. A light source assembly for a Mini LED backlight module, characterized in that: include: Circuit substrate, light-emitting unit, anti-reflection film layer, metal layer, light-shielding layer; A plurality of light-emitting units arranged on the front side of the circuit substrate; Plate an anti-reflection film layer on the front surface of the circuit substrate and the surface of the light-emitting unit; Plating a metal layer on the surface of the anti-reflection film in a direction away from the circuit substrate; A light shielding layer is plated on the surface of the metal layer to form a light shielding layer covering the front surface of the circuit substrate and the surface of each light emitting unit; The light shielding layer and the metal layer on the front light emitting surface of the light emitting unit are removed, and the front light emitting surface of the light emitting unit is a surface of the light emitting unit away from the circuit substrate and parallel to the circuit substrate; At least a part of the positive light emitting surface of the light emitting unit after the light shielding layer and the metal layer are removed is in a light-transmitting state; Only the anti-reflection film is left on the positive light-emitting surface of the light-emitting unit, and the anti-reflection film, the metal layer and the light-shielding layer are left on the light-emitting surfaces on both sides of the light-emitting unit.

2. The light source assembly for a Mini LED backlight module according to claim 1, characterized in that: The anti-reflection film layer comprises at least one high-refractive-index film layer and at least one low-refractive-index film layer.

3. The light source assembly for a Mini LED backlight module according to claim 2, characterized in that: The total thickness of the anti-reflection film layer is 100-600nm.

4. The light source assembly for a MiniLED backlight module according to claim 1, characterized in that: The material of the metal layer is selected from silver, aluminum, zinc or any combination thereof.

5. The light source assembly for a Mini LED backlight module according to claim 4, characterized in that: The total thickness of the metal layer is 10-200 nm.

6. A method for manufacturing a light source assembly for a Mini LED backlight module, used to manufacture the light source assembly as claimed in claim 1, characterized in that: A plurality of light-emitting units are arranged on the front side of the circuit substrate; Plate an anti-reflection film layer on the front surface of the circuit substrate and the surface of the light-emitting unit; Plating a metal layer on the surface of the anti-reflection film in a direction away from the circuit substrate; Sputtering black substrate molecules on the surface of the metal layer to form a light shielding layer covering the front surface of the circuit substrate and the surface of each light-emitting unit; The light shielding layer and the metal layer on the front light emitting surface of the light emitting unit are removed, and the front light emitting surface of the light emitting unit is a surface of the light emitting unit away from the circuit substrate and parallel to the circuit substrate; At least a part of the positive light emitting surface of the light emitting unit after the light shielding layer and the metal layer are removed is in a light-transmitting state.

7. The method for manufacturing a light source assembly for a Mini LED backlight module according to claim 6, characterized in that: An anti-reflection film layer is plated on the front surface of the circuit substrate and the surface of the light-emitting unit, and the plating method includes: a combination of one or more methods selected from magnetron sputtering, vacuum evaporation, vacuum sputtering and arc ion plating.

8. The method for manufacturing a light source assembly for a Mini LED backlight module according to claim 6, characterized in that: A metal layer is plated on the surface of the anti-reflection film in a direction away from the circuit substrate, The coating methods include: one or more combinations of magnetron sputtering, vacuum evaporation, vacuum sputtering and arc ion plating.

9. The method for manufacturing a light source assembly for a Mini LED backlight module according to claim 6, characterized in that: The substrate molecules are sputtered on the surface of the metal layer by a magnetron sputtering method.

10. The method for manufacturing a light source assembly for a Mini LED backlight module according to claim 6, characterized in that: At least a portion of the light shielding layer and the metal layer is removed, and the removal method includes: a combination of one or more methods of laser etching, grinding, and plasma etching.

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