Uniformly-spliced Mini LED backlight source module

Abstract

The invention discloses a uniformly spliced Mini LED backlight source module which comprises more than two PCBs, each PCB comprises a plurality of LED chips, a packaging layer covering the LED chips and a reflecting layer covering the area except the LED chips and the packaging layer; wherein the packaging layer comprises a first packaging layer and a second packaging layer, the first packaging layer and the second packaging layer are of convex structures, and the first packaging layer covers the LED chip located on the outermost edge of the PCB. Through the structure of the packaging layer, the light-emitting angle of the Mini LED is increased, and the cost is reduced. Meanwhile, on the premise that the number of the Mini LEDs is reduced, the problem that the splicing position of the Mini LEDs is dark is effectively solved through matching of the two different packaging layer structures, and the effect that the light color of the spliced Mini LED backlight module is uniform is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of LED display, and in particular relates to a Mini LED backlight module with uniform splicing. Background Art

[0002] Mini LED backlight technology with dynamic dimming technology has the advantages of high contrast and good display effect, and its related products have gradually increased in the market. Color gamut is an important indicator to measure the display effect, including NTSC, DCI-P3 and other standards. Mini LED display products mostly use blue light chips plus quantum dot films to achieve ultra-high color gamut. However, due to the high cost of Mini LED display products, especially when there are more partitions, the cost increases significantly, further affecting its penetration in the display market. By increasing the angle of Mini LED, the number of Mini LEDs can be effectively reduced to achieve cost reduction while maintaining uniformity.

[0003] Mini LED backlight modules for LCD display applications are currently mostly made by splicing multiple small-sized module boards due to the impact of manufacturing process and precision. However, due to various reasons (such as warping and gaps), the brightness of the splicing area is darker than other parts of the module, resulting in uneven effect of the entire backlight module. How to solve the problem of dark Mini LED splicing areas while reducing the number of Mini LEDs and obtain a Mini LED backlight module with uniform splicing is an issue that needs to be solved urgently. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a Mini LED backlight source module with uniform splicing, which effectively improves the darkness at the Mini LED splicing points through the structure of the packaging layer, thereby obtaining a uniform light color effect.

[0005] In order to achieve the purpose, the technical solution adopted by the present invention is as follows:

[0006] A Mini LED backlight module with uniform splicing, comprising two or more PCBs, each of which comprises a plurality of LED chips, a packaging layer covering the LED chips, and a reflective layer covering an area other than the LED chips and the packaging layer;

[0007] The packaging layer includes a first packaging layer and a second packaging layer, the first packaging layer and the second packaging layer are convex structures, and the first packaging layer covers the LED chip at the outermost edge of the PCB.

[0008] Preferably, the two side surfaces of the first encapsulation layer are symmetrically arranged with the center of the first encapsulation layer as the center line;

[0009] The side surface of the first encapsulation layer includes a plurality of continuously connected curves, and at least a portion of the curves of the side surface of the first encapsulation layer are in an arc shape;

[0010] The contact point between the edge of the first packaging layer and the PCB is set as a starting point D1, the curves of the side surface of the first packaging layer include a first curve, a second curve and a third curve, the starting end of the first curve overlaps with the starting point D1, and the second curve is set between the first curve and the third curve;

[0011] The terminal end of the first curve is set as the end point D2, the terminal end of the second curve is set as the end point D3, the angle formed by the line between the starting point D1 and the end point D2 and the PCB surface is set to θ1, the angle formed by the line between the end point D2 and the end point D3 and the PCB surface is set to θ2, the third curve is a partial arc from the end point D3 to the center of the first packaging layer, the angle formed by the starting end of the third curve and the PCB surface is θ3, and the above angles are: θ3>θ2>θ1.

[0012] Preferably, the second encapsulation layer is quasi-circular in a top view direction, and the cross section of the second encapsulation layer includes two symmetrically arranged basic units, and the side surfaces of the basic units include a plurality of continuously connected curves;

[0013] The curves of the side surface of the basic unit include a fourth curve, a fifth curve and a sixth curve, the fifth curve is arranged between the fourth curve and the sixth curve, the starting end of the fourth curve is the contact point between the outermost edge of the second packaging layer and the PCB, and the ending end of the sixth curve is the center point of the top surface of the second packaging layer;

[0014] The angle between the fourth curve and the PCB is between 35° and 70°;

[0015] The angle between the straight line formed by adjacent points in the fifth curve and the PCB decreases from the direction toward the center point of the top surface of the second packaging layer;

[0016] The angle formed by the starting end of the fourth curve and the adjacent point of the fifth curve is between 80° and 110°, the angle formed by the straight line formed by the starting end of the fifth curve and the nearest point of the adjacent sixth curve and the PCB is between -5° and 5°, and the sixth curve is parallel to the PCB or presents an angle of -5° to 5°.

[0017] Preferably, the light emitting surface of the LED chip is provided with at least one Brass reflective layer.

[0018] Preferably, the intensity of the LED chip refracted from the first packaging layer to the reflective layer is less than the intensity of the LED chip refracted from the second packaging layer to the reflective layer.

[0019] Preferably, the ratio of the side height of the first encapsulation layer to the widest part of the first encapsulation layer is 0.25-0.33.

[0020] Preferably, the ratio of the side height of the second encapsulation layer to the widest part of the second encapsulation layer is 0.27-0.35.

[0021] Preferably, the packaging layer material is composed of one or more of silicone rubber, silicone resin, and epoxy resin.

[0022] Preferably, the reflectivity of the reflective layer to the LED chip is ≥80%.

[0023] Preferably, it further comprises a fluorescence conversion film.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The Mini LED backlight module with uniform splicing proposed by the present invention increases the light-emitting angle of Mini LED and reduces the cost through the structure of the packaging layer. At the same time, under the premise of reducing the number of Mini LEDs, the two different packaging layer structures are matched to effectively improve the problem of dark Mini LED splicing, and achieve the effect of uniform light color of the spliced ​​Mini LED backlight module. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0027] Figure 1 A top view of a single Mini LED backlight module of the present invention;

[0028] Figure 2 It is a side view of the spliced ​​Mini LED backlight module of the present invention;

[0029] Figure 3 is a side view of a first encapsulation layer of the present invention;

[0030] Figure 4 is a side view of the second encapsulation layer of the present invention;

[0031] Figure 5 This is a top view of the spliced ​​Mini LED backlight module of the present invention;

[0032] Figure 6 This is a top view of another spliced ​​Mini LED backlight module of the present invention;

[0033] Figure 7 It is a schematic diagram of the light emitting angle and relative intensity of the first packaging layer and the second packaging layer of the Mini LED backlight module of the present invention.

[0034] Description of reference numerals:

[0035] 1. PCB; 2. LED chip; 3. First packaging layer; 4. Second packaging layer; 5. Reflection layer; 6. Fluorescence conversion film. DETAILED DESCRIPTION

[0036] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth in order to fully understand the present invention, and the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0037] 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.

[0038] Example 1

[0039] like Figure 1-Figure 5 As shown, this embodiment provides a Mini LED backlight module, including 4 PCBs 1, each PCB 1 including a plurality of LED chips 2, the LED chips 2 are arranged in a square matrix, a packaging layer covering the LED chips 2, and a reflective layer 5 covering the area other than the packaging layer on the LED chips 2 and the packaging layer. Among them, the packaging layer includes at least two structures, including a first packaging layer 3 on the LED chip 2 at the edge of the PCB 1, and a second packaging layer 4 having a second packaging structure. The first packaging layer 3 and the second packaging layer 4 are both convex structures, wherein the structures of the first packaging layer 3 and the second packaging layer 4 are different.

[0040] The two side surfaces of the first encapsulation layer 3 are symmetrically arranged with the center of the first encapsulation layer as the center line, the side surface of the first encapsulation layer 3 includes a plurality of continuously connected curves, at least a portion of the curves of the side surface of the first encapsulation layer are in an arc shape, the contact point between the edge of the first encapsulation layer and the PCB is set as the starting point D1, the curves of the side surface of the first encapsulation layer include a first curve, a second curve and a third curve, the starting end of the first curve overlaps with the starting point D1, and the second curve is set between the first curve and the third curve;

[0041] The terminal end of the first curve is set as the end point D2, the terminal end of the second curve is set as the end point D3, the angle formed by the line between the starting point D1 and the end point D2 and the PCB surface is set to θ1, the angle formed by the line between the end point D2 and the end point D3 and the PCB surface is set to θ2, the third curve is a partial arc from the end point D3 to the center of the first packaging layer, the angle formed by the starting end of the third curve and the PCB surface is θ3, and the above angles are: θ3>θ2>θ1.

[0042] The second packaging layer 4 is quasi-circular when viewed from above. The cross section of the second packaging layer 4 is composed of two nearly symmetrical basic units, and the side of the basic unit includes a number of continuously connected curves. The curves on the side of the basic unit include a fourth curve, a fifth curve and a sixth curve. The fifth curve is arranged between the first curve and the third curve. The starting end of the fourth curve is the contact point with the PCB at the edge of the second packaging layer, and the ending end of the sixth curve is the center point of the top surface of the second packaging layer. The angle between the fourth curve and the PCB is between 35-70°. The angle between the straight line formed by the adjacent points in the fifth curve and the PCB decreases from the direction toward the center point of the top surface of the second packaging layer. The angle between the starting end of the fourth curve and the adjacent point of the fifth curve is between 80° and 110°. The angle between the straight line formed by the starting end of the fifth curve and the nearest point of the adjacent sixth curve and the PCB is between -5° and 5°. The sixth curve is parallel to the PCB or presents an angle of -5 to 5°.

[0043] In this embodiment, the light-emitting surface of the LED chip 2 is provided with 10 layers of Brass reflective layers. The intensity of the LED chip 2 refracted to the reflective layer through the first encapsulation layer 3 is less than the intensity refracted to the reflective layer through the second encapsulation layer 4. The ratio of the side height of the first encapsulation layer 3 to the widest part of the first encapsulation layer is 0.25. The ratio of the side height of the second encapsulation layer 4 to the widest part of the second encapsulation layer 4 is 0.3. The materials of the first encapsulation layer 3 and the second encapsulation layer 4 are composed of silicone rubber, which are the same material and have a refractive index of 1.47. The reflectivity of the reflective layer 5 to the LED chip 2 is 85%. In this embodiment, the color of the LED chip 2 is blue, and its peak wavelength is 445nm. It also includes a fluorescence conversion film 6, which forms a fluorescence conversion layer. The fluorescence conversion layer is used to absorb part of the blue light emitted by the LED chip 2, emit green light and red light, and mix into white light. In this embodiment, the material of the fluorescence conversion layer includes green quantum dots with green light emission and red quantum dots with red light emission.

[0044] Example 2

[0045] like Figure 6 As shown, the present invention provides a Mini LED backlight module, which is different from Example 1 in that it includes 8 PCBs 1, each PCB 1 includes a plurality of LED chips 2, and the plurality of LED chips 2 are arranged in a prism shape. The ratio of the side height of the first encapsulation layer 3 to the widest part of the first encapsulation layer is 0.29, and the first encapsulation layer 3 is composed of silicone rubber, and its refractive index is 1.41.

[0046] The ratio of the side height of the second packaging layer 4 to the widest point of the second packaging layer 4 is 0.35, the second packaging layer is quasi-circular in the top view direction, the cross-section of the second packaging layer includes two symmetrically arranged basic units, and the side of the basic unit includes a number of continuously connected curves; the curves on the side of the basic unit include a fourth curve, a fifth curve and a sixth curve, the fifth curve is arranged between the first curve and the third curve, the starting end of the fourth curve is the contact point with the PCB at the edge of the second packaging layer, which is D4, and the ending end of the sixth curve is the center point of the top surface of the second packaging layer, which is set to D7; the angle between the fourth curve and the PCB is 70°, the angle formed by the starting end of the fourth curve and the adjacent point of the fifth curve is 110°, the starting end of the fifth curve is D5, and the angle between the straight line formed by the fifth curve and the nearest point of the adjacent sixth curve and the PCB is 5°, the starting end of the sixth curve is D6, and the sixth curve is parallel to the PCB or presents an angle of 5°.

[0047] The material of the second encapsulation layer 4 is composed of silicone resin, and its refractive index is 4.8. In this embodiment, the light-emitting surface of the LED chip is provided with 10 layers of brass reflective layers. In this embodiment, the reflectivity of the reflective layer 5 to the LED chip 2 is 80%. In this embodiment, a fluorescence conversion film is also included, and the fluorescence conversion film forms a fluorescence conversion layer. The material of the fluorescence conversion layer includes nitride green powder with green light emission, K2SiF6:Mn with red light emission. 4+ Phosphor.

[0048] Example 3

[0049] The present invention provides a Mini LED backlight module, which is different from Example 1 in that the ratio of the side height of the first encapsulation layer 3 to the widest part of the first encapsulation layer is 0.33, and the first encapsulation layer 3 is composed of a mixture of silicone rubber and silicone resin, and its refractive index is 1.52. In this embodiment, the first encapsulation layer 3 also contains diffusion particles SiO2.

[0050] The ratio of the side height of the second encapsulation layer 4 to the widest part of the second encapsulation layer 4 is 0.27. The second encapsulation layer is quasi-circular when viewed from above. The cross section of the second encapsulation layer includes two symmetrically arranged basic units. The side of the basic unit includes a number of continuously connected curves. The curves on the side of the basic unit include a fourth curve, a fifth curve and a sixth curve. The fifth curve is arranged between the first curve and the third curve. The starting end of the fourth curve is the contact point between the edge of the second encapsulation layer and the PCB. The ending end of the sixth curve is the center point of the top surface of the second encapsulation layer. The angle between the fourth curve of the second encapsulation layer 4 and the PCB1 is 35°. The angle between the straight line formed by the adjacent points in the fifth curve and the PCB decreases from the direction toward the center point of the top surface of the second encapsulation layer. The angle between the starting end of the fourth curve and the adjacent point of the fifth curve is 80°. The angle between the straight line formed by the starting end of the fifth curve and the nearest point of the adjacent sixth curve and the PCB is -5°. The sixth curve is parallel to the PCB or presents an angle of 0°. The first encapsulation layer 3 is composed of silicone rubber, and its refractive index is 1.5. In this embodiment, the second encapsulation layer 4 further includes diffusion particles ZrO2.

[0051] Due to various reasons (such as warping and gaps), the brightness of the joints is darker than other parts of the module, resulting in uneven effect of the entire backlight module. This application achieves uniformity through two different packaging layers at different positions of the PCB (one circle on the outside + two different packaging layers inside). The corresponding structure is as described in the structure of the above embodiments 1-3. The structure of the first packaging layer and the second packaging layer determines the luminous effect. Figure 7, the central light intensity of the second packaging layer is lower (near 0°), and the ratio of central light intensity to maximum light intensity is between 0.1-0.3. The ratio of central light intensity to maximum light intensity of the first packaging layer is between 0.3-0.5. Since the central intensity of the second packaging layer is relatively low, more light is refracted / reflected to the PCB, showing an obvious dark band at the junction. The light at the edge of the first packaging layer is less than that of the second packaging layer, and more light makes up for the above dark band, thereby achieving uniformity.

[0052] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A Mini LED backlight module with uniform splicing, characterized in that: The method comprises two or more PCBs, each of which comprises a plurality of LED chips, a packaging layer covering the LED chips, and a reflective layer covering an area other than the LED chips and the packaging layer; The packaging layer includes a first packaging layer and a second packaging layer, the first packaging layer and the second packaging layer are convex structures, and the first packaging layer covers the LED chip at the outermost edge of the PCB.

2. The uniformly spliced ​​Mini LED backlight module according to claim 1, characterized in that: The two side surfaces of the first encapsulation layer are symmetrically arranged with the center of the first encapsulation layer as the center line; The side surface of the first encapsulation layer includes a plurality of continuously connected curves, and at least a portion of the curves on the side surface of the first encapsulation layer are in an arc shape; The contact point between the edge of the first packaging layer and the PCB is set as a starting point D1, the curves of the side surface of the first packaging layer include a first curve, a second curve and a third curve, the starting end of the first curve overlaps with the starting point D1, and the second curve is set between the first curve and the third curve; The terminal end of the first curve is set as the end point D2, the terminal end of the second curve is set as the end point D3, the angle formed by the line between the starting point D1 and the end point D2 and the PCB surface is set to θ1, the angle formed by the line between the end point D2 and the end point D3 and the PCB surface is set to θ2, the third curve is a partial arc from the end point D3 to the center of the first packaging layer, the angle formed by the starting end of the third curve and the PCB surface is θ3, and the above angles are: θ3>θ2>θ1.

3. The uniformly spliced ​​Mini LED backlight module according to claim 1, characterized in that: The second encapsulation layer is quasi-circular in a top view direction, the cross section of the second encapsulation layer includes two symmetrically arranged basic units, and the side surfaces of the basic units include a plurality of continuously connected curves; The curves of the side surface of the basic unit include a fourth curve, a fifth curve and a sixth curve, the fifth curve is arranged between the fourth curve and the sixth curve, the starting end of the fourth curve is the contact point between the outermost edge of the second packaging layer and the PCB, and the ending end of the sixth curve is the center point of the top surface of the second packaging layer; The angle between the fourth curve and the PCB is between 35° and 70°; The angle between the straight line formed by adjacent points in the fifth curve and the PCB decreases from the direction toward the center point of the top surface of the second packaging layer; The angle formed by the starting end of the fourth curve and the adjacent point of the fifth curve is between 80° and 110°, the angle formed by the straight line formed by the starting end of the fifth curve and the nearest point of the adjacent sixth curve and the PCB is between -5° and 5°, and the sixth curve is parallel to the PCB or presents an angle of -5° to 5°.

4. The uniformly spliced ​​Mini LED backlight module according to claim 1, characterized in that: The light emitting surface of the LED chip is at least provided with a brass reflective layer.

5. The uniformly spliced ​​Mini LED backlight module according to any one of claims 1 to 3, characterized in that: The intensity of the LED chip refracted from the first packaging layer to the reflective layer is less than the intensity of the LED chip refracted from the second packaging layer to the reflective layer.

6. The uniformly spliced ​​Mini LED backlight module according to any one of claims 1-2, characterized in that: The ratio of the side height of the first encapsulation layer to the widest part of the first encapsulation layer is 0.25-0.

33.

7. The uniformly spliced ​​Mini LED backlight module according to any one of claims 1 or 3, characterized in that: The ratio of the side height of the second encapsulation layer to the widest part of the second encapsulation layer is 0.27-0.

35.

8. The uniformly spliced ​​Mini LED backlight module according to claim 1, characterized in that: The packaging layer material is composed of one or more of silicone rubber, silicone resin, and epoxy resin.

9. The uniformly spliced ​​Mini LED backlight module according to claim 1, characterized in that: The reflectivity of the reflective layer to the LED chip is ≥80%.

10. The uniformly spliced ​​Mini LED backlight module according to claim 1, characterized in that: Also includes a fluorescent conversion coating.

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