A low-energy light source component for Mini LED backlight module and its manufacturing method

Abstract

This patent relates to a low-energy light source assembly for a Mini LED backlight module and its manufacturing method, comprising: disposing a plurality of light-emitting units on the front of a circuit substrate, with trapezoidal grooves formed between the light-emitting units; coating the front of the circuit substrate and the surface of the light-emitting units with an anti-reflection film; coating the surface of the anti-reflection film with a highly reflective 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 surfaces of the light-emitting units; and removing the light-shielding layer and metal layer from the front light-emitting surface of the light-emitting units. The light source assembly of this patent is suitable for Mini LED backlight modules. The trapezoidal groove design between the light-emitting units can not only increase the bonding strength between the coating layer and the light-emitting units, but also increase the heat dissipation area, effectively increasing the luminous flux 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 low-energy light source assembly for a Mini LED backlight module. Background Art

[0002] Mini LED backlights, a new type of backlight, are widely used in the LCD display field. Compared to traditional LED backlight sources, they are lightweight, have high resolution, and consume less power, and have attracted much attention in recent years. Mini LEDs, also known as submillimeter light-emitting diodes, achieve local dimming within a precise range by densely arranging a large number of Mini LED chips—thousands of them—with narrow pitches of hundreds of microns. The halo effect is a challenge faced by local dimming technology. Traditionally, the smaller the halo area, the better. However, minimizing the halo in a Mini-LED backlight can create a mosaic-like effect when implementing local dimming, reducing the display quality. Conversely, excessive halo areas can significantly impact the high contrast achieved by the Mini-LED backlight. Selecting a light source component that matches the Mini LED backlight module is crucial for adjusting the halo effect and improving the display quality of the Mini LED.

[0003] In the prior art, an opaque black ink layer or black glue layer (hereinafter collectively referred to as a black deposition layer) is produced on a PCB board through processes such as inkjet printing, black glue filling, and hot lamination to solve the problem that after the Mini LED chip and the Mini LED chip package (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 turns silver after melting and covers the surface of the solder pad. The silver color has a reflective property, resulting in the display screen not being dark enough when the screen is black, which reduces the contrast of the display screen and affects the display effect.

[0004] The prior art CN114975394A discloses an LED light source assembly, a manufacturing method thereof, and an LED display screen, which forms a black deposition layer by sputtering and depositing molecules of a black substrate onto the front of a circuit substrate and the surface of each light-emitting unit. The process is no longer limited by the flatness of the area where the light-shielding layer is to be formed, so that the area to be shaded is 100% covered, and the formed black deposition layer is uniform, which can reduce the black chromaticity difference at each position of the black deposition layer, thereby improving the contrast of the display screen made using the LED light source assembly and avoiding the occurrence of mottled light at the side angle of the display screen. This solves the problem that the manufacturing process of the black deposition layer on the PCB board in the existing display screen is limited by flatness, the uniformity and consistency of the manufactured light-shielding layer 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] Mini LED backlight modules have higher requirements for the dimming accuracy of light source components than traditional LEDs. As the pixel pitch in Mini LED backlight modules decreases, the proportion of 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 black deposition layer must be evenly covered to improve the contrast of the display screen, which plays a significant role in improving the display effect of Mini LED. Therefore, in the application of Mini LED backlight modules, there are higher technical requirements for the manufacturing accuracy of light source components. Summary of the Invention

[0006] This patent provides a low-energy light source component for a Mini LED backlight module, aiming to provide a low-energy light source component suitable for a Mini LED backlight module with fast heat dissipation, low energy consumption and high light efficiency. This patent sets trapezoidal grooves between each light-emitting component to increase the bonding force between the light-emitting unit and the coating layer, solving the display problems of uneven distribution of the black deposition layer on the PCB board, low light efficiency and mottled phenomenon in the prior art. This patent provides a method for making a light-shielding layer on a PCB board, the light-shielding layer includes but is not limited to a black deposition layer, the flatness, uniformity and consistency of the light-shielding layer on the prepared PCB board are better than those of the prior art, avoiding coverage of dead corners, and the side of the light-emitting unit in the low-energy light source component for the Mini LED backlight module can be completely covered by the light-shielding layer to provide sufficient brightness and a uniformly distributed light source, so as to solve the problems of insufficient brightness, uneven distribution and excessive power consumption of the light source component in the prior art.

[0007] This patent provides a low-energy light source assembly for a Mini LED backlight module and its manufacturing method. The structure of the light source assembly includes: a circuit substrate, a light-emitting unit, an anti-reflection film layer, a metal layer, and a light-shielding layer;

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

[0009] A trapezoidal groove is provided between a plurality of light-emitting units on the front surface of the circuit substrate;

[0010] The distance between the bottoms of every two light-emitting units is smaller than the distance between the tops of the light-emitting units;

[0011] Plate an anti-reflective film layer on the front surface of the circuit substrate and the surface of the light-emitting unit;

[0012] Plating a metal layer on the surface of the anti-reflection film in a direction away from the circuit substrate;

[0013] Plating a light-shielding layer 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;

[0014] 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, where the front light-emitting surface is the side of the light-emitting unit that is away from the circuit substrate and parallel to the circuit substrate;

[0015] At least a portion of the positive light-emitting surface of the light-emitting unit after at least a portion of the light-shielding layer and the metal layer is removed is in a light-transmitting state.

[0016] Furthermore, the anti-reflection film includes 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 superimposed on each other.

[0017] Furthermore, the total thickness of the anti-reflection film layer is 100-600 nm.

[0018] Furthermore, the material of the metal layer is selected from silver, aluminum, zinc or any combination thereof.

[0019] Furthermore, the total thickness of the metal layer is 10-200 nm.

[0020] Furthermore, the substrate is selected from at least one of oxides, silicides, and nitrides.

[0021] Furthermore, the light shielding layer may be, but is not limited to, a black deposition layer.

[0022] Furthermore, the state where 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 is:

[0023] 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;

[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, and the anti-reflection film layer is partially removed;

[0026] or

[0027] The light shielding layer and the metal layer on the front light emitting surface of the light emitting unit are completely removed.

[0028] A method for manufacturing a low-energy light source component for a Mini LED backlight module, characterized in that:

[0029] A plurality of light-emitting units are arranged on the front surface of the circuit substrate;

[0030] A trapezoidal groove is provided between a plurality of light-emitting units on the front surface of the circuit substrate;

[0031] Plate an anti-reflective film layer on the front surface of the circuit substrate and the surface of the light-emitting unit;

[0032] Plating a metal layer on the surface of the anti-reflection film in a direction away from the circuit substrate;

[0033] Sputtering black matrix 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;

[0034] 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, so that the front light-emitting surface of the light-emitting unit is the side of the light-emitting unit away from the circuit substrate and parallel to the circuit substrate;

[0035] At least a portion of the positive light-emitting surface of the light-emitting unit after at least a portion of the light-shielding layer and the metal layer is removed is in a light-transmitting state.

[0036] 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: one or more combinations of magnetron sputtering, vacuum evaporation, vacuum sputtering and arc ion plating.

[0037] Furthermore, a metal layer is plated on the surface of the anti-reflection film in a direction away from the circuit substrate.

[0038] The plating methods include: one or more combinations of magnetron sputtering, vacuum evaporation, vacuum sputtering and arc ion plating.

[0039] Furthermore, the substrate molecules are sputtered onto the surface of the metal layer by a magnetron sputtering method.

[0040] 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.

[0041] The low-energy light source assembly suitable for the Mini LED backlight module provided in this patent has a simple manufacturing process. The groove between each two light-emitting units is set to a trapezoidal shape, and the anti-reflection film layer, the metal layer and the light-shielding layer are plated on the front of the circuit substrate and the surface of the light-emitting unit. After the light-shielding layer and the metal layer on the front surface of the light-emitting unit are removed, it can be used as a light source assembly. The design of the trapezoidal groove increases the bonding force between the plated film layer and the surface of the light-emitting unit. The anti-reflection film layer, the metal layer and the light-shielding layer are more uniform on the surface of the light-emitting unit and are not easy to break. Since the light-emitting units required for the Mini LED backlight module are more than thousands of micron-level chips, the heat generated during operation will affect their luminous performance. Compared with the existing technology, the trapezoidal groove in this patent increases the heat dissipation area of the light-emitting unit, and the heat dissipation effect is significantly improved, which plays a great role in reducing the energy consumption of the light source assembly and extending its service life.

[0042] In this patent, the anti-reflection film is plated on the front of the circuit substrate and the surface of each light-emitting unit. The anti-reflection film can reflect specific wavelengths. The ideal anti-reflection effect can be achieved by adjusting the number of anti-reflection film layers. 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 increases the polarization degree of the emitted light and enhances the intensity of the light emitted by the light-emitting unit, thereby reducing power consumption and reducing costs. The metal layer deposited on the surface of the anti-reflection film in this patent acts as a reflector. The metal layer reflects the side light and the barrier effect of the metal layer prevents the light-shielding 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

[0043] 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.

[0044] In addition, for ease of understanding, the size ratios of the components in the drawings described below are adjusted accordingly.

[0045] Figure 1 This is a cross-sectional view of the arrangement of the light-emitting units on the circuit substrate in the patent solution;

[0046] Figure 2 This is a schematic diagram of the structure of the patented light source component after coating with a film layer;

[0047] Figure 3 It is a structural diagram of the light source assembly of this patent;

[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 describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different perspectives and applications without departing from the spirit of the present invention. It should be noted that any process equipment or devices not specifically noted in the following examples are conventional equipment or devices in the art. Furthermore, it should be understood that the reference to one or more method steps in the present invention does not exclude the presence of other method steps before or 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 reference to one or more device / device combinations in the present invention does not exclude the presence of other devices / devices before or after the combination step, or the insertion of other devices / devices between two explicitly mentioned devices / devices, unless otherwise specified. Furthermore, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying the method steps, and is not intended to limit the order of the method steps or the scope of the present invention. Any changes or adjustments to their relative relationships, without materially altering the technical content, should be considered within 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 herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. 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 figures. For example, if the device in the 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" can include both "above" and "below". The device can 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 commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of this patent 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 low-energy 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 surface of the circuit substrate, wherein the grooves between the light-emitting units are trapezoidal, and the distance between the bottoms of the light-emitting units is smaller than the distance between the tops of the light-emitting units;

[0053] In this embodiment, the front surface of the circuit substrate is provided with a plurality of solder pads for electrically connecting to the electrodes of the light-emitting units. The solder pads can be arranged in a matrix; however, other distribution patterns can be employed as needed, and this embodiment does not impose any specific limitations thereon. In some examples of this embodiment, the solder pads can be made of, but are not limited to, copper, silver, or gold. In this embodiment, the solder pads on the front surface of the circuit substrate can be used for, but are not limited to, electrically connecting to the electrodes of the light-emitting units. The electrodes of the light-emitting units can be electrically connected to the corresponding solder pads using, but are not limited to, solder or conductive adhesive. The light-emitting units in this embodiment can be, but are not limited to, MiniLED chip packages. In this embodiment, the LED chips can be sized to include at least one of MiniLED chips, MicroLED chips, and conventional LED chips larger than MiniLED chips. Preferably, the LED chip electrodes can be arranged to include at least one of flip-chip LED chips, face-mount LED chips, and vertical LED chips. When the light-emitting units are LED chips, flip-chip LED chips are preferred. Of course, it should be understood that the LED light source assembly in this embodiment is not limited to applications in 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 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, including 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 boards. The circuit substrate in this embodiment can also be made of flexible materials, such as but not limited to polyester film, polyimide film, and fluorinated ethylene propylene film. In some examples, corresponding circuits and corresponding welding methods can be integrated within or on the surface of the circuit substrate according to application requirements, including but not limited to circuits connected to the light-emitting unit and driving circuits.

[0055] In one 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 some may be the same and some may be different, and the specific arrangement may be flexibly determined 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] The grooves between the light-emitting units are trapezoidal, and the distance between the bottoms of the light-emitting units is smaller than the distance between the tops of the light-emitting units. Each light-emitting unit is composed of at least two Mini LED chips, including two trapezoidal Mini LED chip combinations, and a combination of trapezoids and rectangles. This embodiment does not impose any restrictions on this.

[0057] The direction in which each light emitting unit is connected to the circuit substrate is the bottom, and the direction away from the circuit substrate is the top.

[0058] S202: Plating at least two layers of anti-reflection film on the front surface of the circuit substrate and the surface of the light-emitting unit;

[0059] The anti-reflection film is a multilayer film system made by alternating high and low refractive index materials according to the designed thickness. TiO2 and SiO2 can be used as the high and low refractive index materials respectively for the anti-reflection film, but are not limited to them.

[0060] 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 existing technology. It 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.

[0061] In some preferred embodiments, a binary film system using TiO2 as a high-refractive-index material and SiO2 as a low-refractive-index material is prepared using magnetron sputtering. The TiO2 and SiO2 anti-reflection films prepared using magnetron sputtering exhibit a series of advantages, including good adhesion, uniform thickness, compact film structure, good uniformity, and high mechanical strength. Furthermore, the thickness of the anti-reflection films deposited using magnetron sputtering is easily controlled, making them suitable for nanoscale, high-precision coatings such as Mini LED light source components. Since depositing anti-reflection films on the front surface of circuit substrates and light-emitting units requires high uniformity, thickness, and adhesion, experiments and production have revealed that many factors affect magnetron sputtering, with various factors directly or interactively affecting film properties. Based on these experiments and production, the influence of various factors on the deposited anti-reflection films during magnetron sputtering has been explored, enabling control of film composition, structure, and other properties, providing a basis for depositing anti-reflection films. The main parameters affecting the deposition of anti-reflection films include sputtering power, sputtering gas pressure, substrate temperature, gas flow rate, and target-substrate distance.

[0062] Example 1:

[0063] 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, TiO2 single-layer film and SiO2 single-layer film, or TiO2 film and SiO2 film multilayer structure are prepared in sequence.

[0064] Example 2:

[0065] 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, TiO2 single-layer film and SiO2 single-layer film, or TiO2 film and SiO2 film multilayer structure are prepared in sequence.

[0066] After the anti-reflection film is deposited according to the parameters of Example 1, the reflectivity of the front surface of the circuit substrate and the light-emitting unit surface 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 surface of the circuit substrate and the light-emitting unit surface after coating is measured by an ellipsometer, which increases by about four times compared with before coating, and the peak reflectivity reaches 90%.

[0067] In summary, the expected effect can be achieved by depositing an anti-reflection film according to the parameters provided in the above two examples.

[0068] The total thickness of the anti-reflection film is in the range of 100-600 nm.

[0069] S203: Plating a metal layer on the surface of the anti-reflection film in a direction away from the circuit substrate;

[0070] A metal layer is plated on the surface of the anti-reflective film, facing away from the circuit substrate. The metal layer acts as a reflector. The anti-reflective film, located between the circuit substrate and the metal layer, also acts as an insulator, preventing direct contact between the metal layer and solder joints on the circuit substrate, which could cause circuit short circuits and other issues. The metal layer provides excellent heat dissipation and electromagnetic interference resistance, and has a strong reflective and brightening effect. It is used to reflect light reflected from the anti-reflective film on the light-emitting unit in a direction perpendicular to the horizontal line of the light-emitting unit, effectively enhancing LED brightness and reducing halo effects.

[0071] The material of the metal plating layer is selected from gold, silver, aluminum, copper, zinc, chromium or any combination thereof, or other metals or metal alloys.

[0072] The metal layer may be plated by, but is not limited to, magnetron sputtering, vacuum evaporation plating, and the like.

[0073] Example 1:

[0074] The circuit substrate with the light-emitting unit coated with the anti-reflection film was placed in the magnetron sputtering chamber. Under an inert gas environment, the vacuum degree was reduced to 3×10 -1 Below Pa, the magnetic field is used to guide the metal target to deposit a metal coating on the surface of the anti-reflection 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.

[0075] Example 2:

[0076] The circuit substrate with light-emitting units coated with an anti-reflective film is placed in a vacuum chamber. The metal to be formed into a thin film, such as silver, in the evaporation container is heated, causing its atoms or molecules to vaporize and escape from the surface, forming a vapor flow that is incident on the surface of the circuit substrate and the light-emitting units, condensing to form a metallic silver film.

[0077] As described above, in the preparation of a low-energy light source assembly suitable for a Mini LED backlight module, it is preferred to prepare the metal layer by magnetron sputtering, and the thickness of the deposited metal layer is between 10-200 nm.

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

[0079] Example 1:

[0080] In a vacuum magnetic environment, a magnetic field is used to guide ions to bombard a black substrate, and the molecules of the black substrate are evenly sputtered onto the front surface of the circuit substrate and the surface of each light-emitting unit, thereby depositing and forming a light-shielding layer.

[0081] Example 2:

[0082] 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, thereby depositing and forming a light-shielding layer. In this example, at least two black substrates are bombarded at the same time, so the molecules of at least two black substrates can be sputtered simultaneously to the area where the light-shielding layer needs 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 sputtering the molecules of two black substrates to deposit and form a black layer. It is also possible to sputter the molecules of three or more black substrates to deposit and form a black layer as needed, and this example will not go into details one by one.

[0083] Example 3:

[0084] In a vacuum magnetic environment, a 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 surface 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 a black layer including multiple molecules. The deposition can be divided into multiple times. In this example, the first black substrate is deposited, and the black substrate molecules are uniformly sputtered on the front surface of the circuit substrate and the surface of each light-emitting unit to form a first molecular layer; 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 time, a magnetic field is used to guide ions to bombard the second black substrate, and the second black substrate is uniformly sputtered on the first molecular layer, that is, a uniform second molecular layer is formed on the first molecular layer on the front surface of the circuit substrate and the surface of the light-emitting unit; the third black molecular layer is deposited in the same way. Of course, it should be understood that this example is not limited to the sequential sputtering and deposition of molecules of three black substrates to form a black layer. It is also possible to sequentially sputter and deposit molecules of two or more black substrates 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 achieved by, but is not limited to, manual replacement or automatic replacement by equipment.

[0085] According to the above examples, the sputtering process in this embodiment can adopt but is not limited to the magnetron sputtering process, and the control of the consistency and coverage of the formed light-shielding layer is simple, and the yield rate of the obtained light-shielding layer is high, and the efficiency is high and the cost is low. And the light-shielding layer in this embodiment can be formed by depositing one molecule, or by depositing two or more molecules in layers or by mixed transactions. Therefore, the light-shielding layer can be flexibly set according to the requirements of the transmittance and blackness of the light-shielding layer in the specific application scenario. In particular, the light-shielding layer in the above examples 2 and 3 includes at least two molecules, so the blackness and transmittance and other characteristics of the light-shielding layer can be flexibly adjusted to meet the application requirements, so as to ensure the contrast while improving the display effect.

[0086] At the same time, it should be understood that this 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 this embodiment does not impose any restrictions on it.

[0087] The black substrate in this embodiment can be flexibly selected. For example, in some examples, the black substrate in this embodiment 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 an AZO substrate, a SiO2 substrate, a SiO substrate, a SiC substrate, a Si3N4 substrate, or a composite substrate of at least two of the above substrates may be used, and the oxide substrate, silicide substrate, nitride substrate, and composite substrate in the above examples in this embodiment are all existing conventional materials with low cost and good versatility.

[0088] The thickness of the light shielding layer produced in this embodiment can also be flexibly set based on the 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. This shows that the light shielding layer in this embodiment is an ultra-thin layer, so it does not significantly increase the overall thickness of the Mini LED light source assembly, facilitating the ultra-thinness of the Mini LED light source assembly.

[0089] S205: removing the light shielding layer and the metal layer on the front light emitting surface of the light emitting unit. Optionally, 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.

[0090] In this embodiment, after forming the aforementioned light-shielding layer, the light-shielding layer and metal layer on the front light-emitting surface of each light-emitting unit are completely removed to ensure the light extraction 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 partially removed, and the specific amount of removal when removing a portion, can be dynamically adjusted according to the needs of the specific application scenario. The light emission angle of the Mini LED is measured, and the refractive index required for optimal light extraction efficiency is calculated to determine the portion of the anti-reflection film to be removed. This embodiment does not impose specific restrictions on this.

[0091] This patent provides the following specific embodiments:

[0092] Example 1

[0093] S301: Prepare a circuit substrate; the circuit substrate is made of a flexible material polyimide film. The polyimide film substrate 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 metallic copper.

[0094] S302: A plurality of light-emitting units are arranged on the front side of the circuit substrate; the grooves between the light-emitting units are trapezoidal in shape, the distance between the bottoms of the light-emitting units is smaller than the distance between the tops of the light-emitting units, and the electrodes of the light-emitting units are welded on the pads by conductive glue. The light-emitting units are the packaging bodies of the Mini LED chips, and the Mini LED chips are installed and distributed in an upright state.

[0095] 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.

[0096] The high refractive index material is made of 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 -1 Pa, introduces a magnetic field on the target cathode surface, uses the magnetic field to constrain charged particles to induce argon ions to bombard the target surface, sputtering TiO2 material to deposit and form a TiO2 film.

[0097] The low refractive index material is made of 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, introduces a magnetic field on the target cathode surface, uses the magnetic field to constrain charged particles to induce argon ions to bombard the target surface, sputtering SiO2 material to deposit and form a SiO2 film.

[0098] The TiO2 film and the SiO2 film are sequentially stacked, and the total thickness of the anti-reflection film obtained according to the predicted refractive index is 300 nm.

[0099] S304: On the circuit substrate obtained by completing step S303, metallic silver is sputtered on the surface of the anti-reflection film. The circuit substrate with the light-emitting unit coated with the anti-reflection film is placed in a magnetron sputtering chamber under an argon environment and the vacuum is set to 4×10 -1 Pa, sputtering current 0.5A, using a magnetic field to guide the metal silver target, a metal silver coating is deposited on the surface of the anti-reflection film in S303 away from the circuit substrate, and the thickness of the metal silver is 100nm.

[0100] 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 selected from SiC and AZO. In a vacuum magnetic environment, the vacuum is set to 4×10 -1 Pa, uses the magnetic field to confine 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 is performed 1-3 times according to the transparency of the sputtered coating to obtain a light-shielding layer with a thickness of 150nm.

[0101] S306: Remove the light-shielding 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 light-shielding layer in S304 and S305, set the parameters of the laser de-plating equipment to remove the light-shielding layer and the metal layer on the positive surface of the light-emitting unit. The laser removal of the metal layer and the light-shielding layer has higher process efficiency and removal accuracy, and the removed light-shielding layer and metal layer powder can be recycled to reduce resource waste.

[0102] A reflection-enhancing film, a metal layer, and a light-shielding layer are formed on the flexible circuit substrate described in this embodiment. Only the reflection-enhancing film remains on the front light-emitting surface of the light-emitting unit on the flexible circuit substrate, while the reflection-enhancing film, the metal layer, and the light-shielding layer remain on the light-emitting surfaces on both sides of the light-emitting unit. The light-emitting unit expands the diffusion angle through multiple reflections from the reflection-enhancing film, and is reflected 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 direct brightness of the light-emitting unit. The sputtered metal layer acts as a reflector, eliminating the need for a separate reflective sheet, effectively reducing the distance between the Mini LED light source and the backlight module, making the backlight device thinner, and improving the light utilization efficiency. The light emitted by the Mini LED light-emitting unit has a light concentration within an adjustable range, effectively reducing the influence of the halo effect on the color rendering effect of the Mini LED backlight module, and eliminating the Mura lamp eye phenomenon.

[0103] Example 2

[0104] 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, the corresponding circuit is set on the front of the circuit substrate according to actual application requirements, and a number of solder pads for connecting to the electrode points of the light-emitting unit are set. The solder pads are distributed in a matrix on the front of the circuit substrate, and the material of the solder pads is a metal copper-aluminum alloy.

[0105] S402: A plurality of light-emitting units are arranged on the front surface of the circuit substrate, and the grooves between the light-emitting units are trapezoidal. The distance between the bottoms of the light-emitting units is smaller than the distance between the tops of the light-emitting units. The electrodes of the light-emitting units are welded on the pads by conductive glue. The light-emitting units are the packaging bodies of the Mini LED chips, and the Mini LED chips are installed and distributed in an upright state.

[0106] 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.

[0107] The high refractive index material is made of 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, introduces a magnetic field on the target cathode surface, uses the magnetic field to constrain 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 is made of 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, introduces a magnetic field on the target cathode surface, uses the magnetic field to constrain 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 400 nm.

[0110] S404: On the circuit substrate obtained by completing step S403, metallic silver is sputtered on the surface of the anti-reflection film. The circuit substrate with the light-emitting unit coated with the anti-reflection film is placed in a magnetron sputtering chamber under an argon environment and the vacuum is set to 4×10 -1 Pa, sputtering current 0.5A, using a magnetic field to guide the metal silver target, a metal silver coating is deposited on the surface of the anti-reflection film in S403 away from the circuit substrate, and the thickness of the metal silver is 200nm.

[0111] 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 selected from SiC and SiN. In a vacuum magnetic environment, the vacuum is set to 4×10 -1 Pa, uses the magnetic field to constrain charged particles to induce argon ions to bombard the surface of SiC and SiN targets in sequence to deposit a light-shielding layer with a transparency of less than 30%. Sputtering is performed 2-4 times according to the transparency of the sputtered coating to obtain a light-shielding layer with a thickness of 150nm.

[0112] S406: Remove the light-shielding layer, metal layer and anti-reflection film layer on the front surface of the light-emitting unit. According to the total thickness of the light-shielding 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 light-shielding layer, metal layer and anti-reflection film layer on the front surface of the light-emitting unit. In this embodiment, all the light-shielding layer, metal layer and anti-reflection film layer on the front surface of the light-emitting unit are removed, combined with grinding, plasma etching and other processes. The process is mature and can save costs.

[0113] Comparative Example

[0114] Prepare to complete steps S401 and 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 black deposition layer manufacturing method described in the prior art is light source assembly B1; and the light source assembly S1 is the one that completes steps S401-S406 described in this embodiment.

[0115] Light source assembly D1, light source assembly B1, and light source assembly S1 were installed in Mini LED backlight modules of the same specifications, namely TD1, TB2, and TS3, and temperature cycling tests were performed according to the commonly used industry standards in this field:

[0116] 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;

[0117] 2. Connect T1, T2, and T3 to the power supply according to the rated input voltage, and set the power switch outside the test box;

[0118] 3. Keep the three test chambers at the same room temperature of 25°C;

[0119] 4. When the power is turned on for the first time, the light will continue to glow for 1 minute, which is recorded as t1; turn off the power, then turn it on again, and the light will continue to glow for 10 minutes, which is recorded as t2; repeat the above operation, and the light will continue to glow for 30 minutes, which is recorded as t3; the light will continue to glow for 2 hours, which is recorded as t4; the light will continue to glow for 6 hours, which is recorded as t5; the light will continue to glow for 12 hours, which is recorded as t6; the light will continue to glow for 15 hours, which is recorded as t7. Record the temperature of each time period of continuous lighting.

[0120] temperature TD1 TB2 TS3 t1 25℃ 25℃ 25℃ t2 26.2℃ 26.3℃ 25.4℃ t3 27.2℃ 27.4℃ 25.6℃ t4 29.7℃ 29℃ 26.5℃ t5 38.1℃ 38.7℃ 32℃ t6 47.7℃ 46.2℃ 33.6℃ t7 52.6℃ 49.2℃ 39.4℃

[0121] (The above test experiment was repeated five times, and the temperature was taken as the average value of the five times)

[0122] Compared with the comparative example, the light source assembly of this embodiment works 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 light efficiency is higher. The light source assembly of this patent can reduce the light decay effect caused by excessive temperature during operation and has a longer service life.

[0123] In this embodiment, the production process has low difficulty in control and high yield rate, 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, and dead-angle coverage is achieved. 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 direct brightness of the light-emitting unit and improving the light utilization efficiency. It can ensure the light-emitting efficiency of each light-emitting unit and improve the display effect of the Mini LED backlight module using the light source component.

[0124] Furthermore, those skilled in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of this patent and to form different embodiments. For example, in the claims below, any of the claimed embodiments may be used in any combination.

Claims

1. A low-energy 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 are arranged on the front surface of the circuit substrate; A trapezoidal groove is provided between a plurality of light-emitting units on the front surface of the circuit substrate; The distance between the bottoms of every two light-emitting units is smaller than the distance between the tops of the light-emitting units; 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 anti-reflection film layer has no less than two layers; Plating a metal layer on the surface of the anti-reflection film in a direction away from the circuit substrate; Plating a light-shielding layer 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 shading layer, the metal layer and the anti-reflection film layer on the front light-emitting surface of the light-emitting unit are removed. The front light-emitting surface of the light-emitting unit is the side of the light-emitting unit away from the circuit substrate and parallel to the circuit substrate; only the anti-reflection film is left on the front light-emitting surface of the light-emitting unit, 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.

2. The low-energy light source assembly for a Mini LED backlight module according to claim 1, characterized in that: The anti-reflection film layer includes a high refractive index film layer and a low refractive index film layer stacked crosswise.

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

4. The low-energy light source assembly for a Mini LED backlight module according to claim 1, wherein: The material of the metal layer is selected from silver, aluminum, zinc or any combination thereof.

5. The low-energy 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. The low-energy light source assembly for a Mini LED backlight module according to claim 1, wherein: The substrate is selected from at least one of oxide, silicide, and nitride.

7. The method for manufacturing a low-energy light source assembly for a Mini LED backlight module according to claim 1, wherein: 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: one or more combinations of magnetron sputtering, vacuum evaporation, vacuum sputtering and arc ion plating.

8. The method for manufacturing a low-energy light source assembly for a Mini LED backlight module according to claim 1, wherein: A metal layer is plated on the surface of the anti-reflection film in a direction away from the circuit substrate, The plating methods include: one or more combinations of magnetron sputtering, vacuum evaporation, vacuum sputtering and arc ion plating.

9. The method for manufacturing a low-energy light source assembly for a Mini LED backlight module according to claim 1, wherein: The substrate molecules are sputtered on the surface of the metal layer by a magnetron sputtering method.

10. The method for manufacturing a low-energy light source assembly for a Mini LED backlight module according to claim 1, wherein: 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.

Images