Light source assembly with dual recessed array, method of manufacturing the same, backlight module and display device

Abstract

The application discloses a light source assembly with double-recess arrays, a preparation method thereof, a backlight module and a display device, and comprises a substrate, an LED array and an encapsulation structure. The LED array comprises a plurality of discrete LED chips arranged on the substrate. The encapsulation structure is arranged on the substrate, and covers each LED chip and fills the gaps between the plurality of LED chips. The surface of the encapsulation structure away from the substrate is formed with a plurality of first recesses and a plurality of second recesses. Each first recess is arranged corresponding to each LED chip, and constitutes a first recess array. Each second recess is arranged corresponding to the geometric center of a rectangle surrounded by four adjacent LED chips, and constitutes a second recess array. When light passes through the first recess and the second recess, reflection and transmission occur, so that the brightness above the LED chip is reduced, and the brightness at the gap between the LED chips is increased, thereby improving the light emission uniformity.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a light source assembly with a dual-recessed array, a method for fabricating the same, a backlight module, and a display device. Background Technology

[0002] In direct-lit backlight modules, a common approach to mitigate the bright spot problem caused by excessive light emanating directly above the LED chip is to create a concave optical structure above the LED chip. This can be achieved by applying adhesive over each LED chip to form a concave lens, or by creating a single recess on the surface of the transparent encapsulating layer covering the LED array, corresponding only to the area directly above each LED chip. These concave structures utilize the refractive effect of the interface to diffuse small-angle light outwards, thereby reducing the peak light intensity directly above the chip and improving the uniformity of light emission to some extent.

[0003] However, when pursuing thinner light mixing distances in backlight modules, although traditional concave structures can diffuse the light directly above the LEDs outwards, the diameter of the diffused light spot is still limited within such a short distance, making it difficult to completely cover the gap area between adjacent LEDs. Therefore, even with a concave structure, obvious periodic bright and dark stripes remain on the light-emitting surface, limiting further thinning of the backlight module.

[0004] This brightness difference is particularly noticeable in ultra-thin backlight modules (e.g., those with a light mixing distance of less than 1mm). To mask the dark areas in the gaps, the light source components often require additional layers of optical films such as diffusers and prisms, which not only increases the module thickness and cost but also limits the development of ultra-thin backlight modules. Summary of the Invention

[0005] Therefore, it is necessary to provide a light source component that can improve light emission uniformity, a method for manufacturing the same, a backlight module, and a display device.

[0006] This invention provides the following technical solution:

[0007] A light source assembly includes a substrate, an LED array, and a packaging structure. The LED array includes a plurality of discretely distributed LED chips disposed on the substrate. The packaging structure is disposed on the substrate, covering each LED chip and filling the gaps between the plurality of LED chips. The surface of the packaging structure away from the substrate has a plurality of first recesses and a plurality of second recesses. Each first recess corresponds to each LED chip, forming a first recess array. Each second recess corresponds to the gaps between the LED chips, forming a second recess array.

[0008] The aforementioned light source assembly has an encapsulation structure on a substrate with an LED array. This encapsulation structure covers multiple LED chips and fills the gaps between them. Simultaneously, on a side away from the substrate, a double-recessed array of multiple recesses is provided. Each first recess corresponds to a single LED chip, and each second recess corresponds to a gap between the LED chips. When light emitted from an LED chip passes through the recess of the first recess, it is reflected at the surface of the recess, reducing the local brightness directly above the LED chip. When light emitted from an LED chip passes through the recess of the second recess, it is transmitted through the recess, increasing the local brightness above the gaps between the LED chips. The first and second recesses work together to improve light emission uniformity.

[0009] In some embodiments, the LED chips in the LED array are arranged in multiple rows and columns, and the second recess is provided at the geometric center of the rectangular area enclosed by two adjacent rows and two adjacent columns of LED chips.

[0010] In some embodiments, the light source assembly satisfies at least one of the following conditions:

[0011] (1) The opening diameter of each of the second recesses is 3 to 3.5 times the height of the encapsulation structure;

[0012] (2) The depth of each of the second recesses is 0.5 to 0.8 times the height of the packaging structure;

[0013] (3) The diameter at half the depth of each of the second recesses is 1.5 to 1.8 times the height of the encapsulation structure.

[0014] In some embodiments, the encapsulation structure is a uniform encapsulation layer. The encapsulation structure is disposed on the substrate and covers each of the LED chips and fills the gaps between the LED chips. The surface of the encapsulation structure away from the substrate has a plurality of first recesses corresponding to each of the LED chips and a plurality of second recesses corresponding to the gaps between the LED chips.

[0015] In some embodiments, the encapsulation structure includes a concave lens adhesive array and a transparent filler adhesive layer. The concave lens adhesive array includes a plurality of discretely distributed concave lens adhesive layers. Each concave lens adhesive layer has a plurality of first recesses formed on its surface away from the substrate. Each concave lens adhesive layer is correspondingly disposed on and covers each LED chip. The transparent filler adhesive layer fills the spaces between the plurality of concave lens adhesive layers. The transparent filler adhesive layer has a plurality of second recesses formed on its surface away from the substrate.

[0016] In some embodiments, the absolute value of the difference between the refractive index of the transparent filler layer and the refractive index of the concave lens layer is not greater than 0.1.

[0017] In some embodiments, the light source assembly satisfies at least one of the following conditions:

[0018] (1) The opening diameter of each of the first recesses is 1.8 to 2.2 times the height of the packaging structure;

[0019] (2) The depth of each of the first recesses is 0.4 to 0.6 times the height of the packaging structure;

[0020] (3) The diameter of each of the first recesses at a depth of 1 / 2 below the recess opening is 0.6 to 0.9 times the height of the packaging structure.

[0021] (4) The height of the packaging structure is 0.4~1 mm.

[0022] In some embodiments, the light source assembly further includes a white ink layer disposed on the substrate at the gap between adjacent LED chips and located between the substrate and the packaging structure.

[0023] In some embodiments, the white ink layer has a reflectivity greater than 85%.

[0024] The present invention also provides a method for fabricating the above-mentioned light source component with a dual-recessed array, comprising the following steps:

[0025] An LED array is fabricated by forming multiple discretely distributed LED chips on a substrate.

[0026] An encapsulation structure is formed on each of the LED chips; the encapsulation structure covers each of the LED chips and fills the gaps between the LED chips, and a plurality of first recesses and a plurality of second recesses are formed on the surface of the encapsulation structure away from the substrate, each of the first recesses corresponding to each of the LED chips and each of the second recesses corresponding to the gaps between the LED chips.

[0027] In addition, the present invention provides a backlight module comprising any of the above-described light source components, or a light source component prepared by the above-described method.

[0028] Optionally, the backlight module further includes a diffuser plate disposed on the side of the packaging structure away from the substrate.

[0029] The backlight module described above, due to the use of the aforementioned light source component, has significantly improved light emission uniformity and can achieve a uniform surface light source at a smaller light mixing distance (e.g., less than 1 mm). Therefore, the overall thickness can be reduced, and the number of optical films such as diffusers and prisms can be reduced, thereby reducing costs and assembly complexity.

[0030] In addition, the present invention also provides a display device, including the light source component described in any of the above claims, the light source component prepared by the above method, or the backlight module described in any of the above claims.

[0031] Therefore, the aforementioned display device, due to the use of this backlight module, has a thinner overall thickness, higher display uniformity, and lower power consumption, making it suitable for ultra-thin screen designs. Attached Figure Description

[0032] Figure 1 This is a partial top view of a light source assembly according to an embodiment of the present invention.

[0033] Figure 2 For along Figure 1 A schematic diagram of the cross-sectional structure obtained by cutting along line AA.

[0034] Figure 3 The light source assembly of another embodiment of the present invention is along Figure 1 A schematic diagram of the cross-sectional structure obtained by cutting along line AA.

[0035] Explanation of reference numerals in the attached figures:

[0036] 10. Substrate; 20. White ink layer; 30. LED array; 40. Packaging structure;

[0037] 410. First recessed array; 420. Second recessed array; 430. Concave lens adhesive array; 440. Transparent filler adhesive layer;

[0038] 301, LED chip; 411, first recess; 421, second recess; 431, concave lens adhesive layer;

[0039] L1, optical path 1; L2, optical path 2. Detailed Implementation

[0040] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0041] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] In this invention, the terms "preferredly," "more preferably," "better," and "even better" refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of the invention. That is, in this invention, "preferredly," "more preferably," "better," and "even better" are merely descriptions of more effective implementations or examples, but do not constitute a limitation on the scope of protection of the invention.

[0044] In this invention, terms such as "further," "even more," and "particularly" are used for descriptive purposes and to indicate differences in content, but should not be construed as limiting the scope of protection of this invention.

[0045] When a numerical range is disclosed in this invention, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Further, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included. Only a few numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0046] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions, and the new technical solutions formed by the combination also fall within the scope of this application.

[0047] like Figure 1 and Figure 2 As shown, one embodiment of the present invention provides a light source assembly with a dual recessed array, including a substrate 10, an LED array 30, and a packaging structure 40. The LED array 30 includes a plurality of discretely distributed LED chips 301, which are disposed on the substrate 10. The packaging structure 40 is disposed on the substrate 10, and covers each LED chip 301 and fills the gaps between the plurality of LED chips 301. A plurality of first recesses 411 and a plurality of second recesses 421 are formed on the surface of the packaging structure 40 away from the substrate 10. Each first recess 411 is disposed corresponding to each LED chip 301, and each second recess 421 is disposed corresponding to the gaps between the LED chips 301.

[0048] It should be noted that, in this application, the surface of the recessed portion is recessed towards the substrate 10 relative to the surface of other parts of the packaging structure 40. A plurality of discretely distributed first recessed portions 411 constitute a first recessed array 410, and a plurality of discretely distributed second recessed portions 421 constitute a second recessed array 420.

[0049] The aforementioned light source assembly has an encapsulation structure 40 on a substrate 10 with an LED array 301. This encapsulation structure 40 covers multiple LED chips 301 and fills the gaps between them. A double-recessed array is provided on the side away from the substrate 10, where a first recess 411 corresponds to each LED chip 301, and second recesses 421 correspond to the gaps between the LED chips 301. When small-angle light emitted from the LED chip 301 (here, angle refers to the angle between the light ray and the normal to the upper surface of the encapsulation structure 40) passes through the recess of the first recess 411, it is reflected at the surface of the recess. By converting the small-angle light into a large-angle light, the bright spot directly above the LED chip 301 is reduced. Figure 2 As shown in the optical path L1, when the large-angle light emitted by the LED chip 301 and the large-angle light reflected by the first recess 411 pass through the recess of the second recess 421, transmission will occur at the recess to increase the local brightness above the gap between the LED chips. Figure 2 The optical path L2 is shown. Thus, the first recess 411 and the second recess 421 work together to improve the uniformity of light output.

[0050] In some embodiments, the substrate 10 is made of one or more of metal or glass fiber reinforced epoxy copper clad laminate (FR-4) or glass, and is suitable for on-board chip packaging (COB) and / or on-glass chip packaging (COG) processes.

[0051] In some embodiments, multiple LED chips 301 in the LED array 30 are arranged in multiple rows and columns, and a second recess 421 is provided at the geometric center of the rectangular area enclosed by two adjacent rows and two adjacent columns of LED chips 301.

[0052] It is understandable that by setting the second recess 421 at the geometric center of the rectangular area enclosed by two adjacent rows and two adjacent columns of LED chips, light can be emitted uniformly from directly above the gap between the LEDs, effectively filling the dark area and further improving the brightness uniformity of the entire light-emitting surface.

[0053] Optionally, the opening diameter of each second recess 421 is 3 to 3.5 times the height of the package structure 40. As an example, the opening diameter of the second recess 421 is 3.0, 3.1, 3.24, 3.46, or 3.5 times the height of the package structure 40, or any value within the range defined by any two of the above points as endpoints. By setting this range of opening diameters for the second recess 421, the light in the gap region obtains an appropriate initial divergence range, thereby uniformly covering the gap between the LED chips 301.

[0054] Optionally, the depth of each second recess 421 is 0.5 to 0.8 times the height of the packaging structure 40. As an example, the depth of the second recess 421 is 0.5, 0.6, 0.62, 0.74, or 0.8 times the height of the packaging structure 40, or any value within the range defined by any two of the above values ​​as endpoints. By setting this depth range of the second recess 421, the degree of light refraction at the recess interface can be controlled, allowing light to be directed towards the dark area at a suitable angle, further improving light emission uniformity.

[0055] Optionally, the diameter at half the depth of each second recess 421 is 1.5 to 1.8 times the height of the packaging structure 40. As an example, the diameter at half the depth of the second recess 421 is 1.5, 1.6, 1.62, 1.74, or 1.8 times the height of the packaging structure 40, or any value within the range defined by any two of the above points as endpoints. By setting this range for the diameter of the second recess 421 at half the depth, the tilt angle of the recess sidewall can be made appropriate, resulting in more stable refraction and diffusion of light at the interface.

[0056] It is understandable that this ratio range can appropriately refract light into the gaps between LED chips 301, thereby increasing the brightness at the gaps.

[0057] It should be noted that, in this application, the depth of the recess refers to the vertical distance between the edge of the upper surface of the recess away from the substrate 10 and the lowest point of the recess, and the lowest point of the recess refers to the position of the recess closest to the substrate 10; the opening diameter of the recess refers to the maximum lateral diameter of the recess located on the upper surface of the packaging structure 40 away from the substrate 10; the maximum lateral diameter refers to the longest line connecting two points on the contour of the recess away from the edge of the upper surface of the substrate 10; and the diameter at half the depth of the recess refers to the maximum lateral diameter of the cross section of the recess parallel to the substrate 10 at half the depth.

[0058] Please continue reading. Figure 2 In some embodiments, the encapsulation structure 40 is a uniform encapsulation layer. The encapsulation structure 40 is disposed on the substrate 10 and covers each LED chip 301 and fills the gap between the multiple LED chips 301. The surface of the encapsulation structure 40 away from the substrate 10 has a plurality of first recesses 411 corresponding to each LED chip 301, and a second recess 421 is formed at the gap position between the corresponding LED chips 301.

[0059] In the aforementioned light source component, the encapsulation structure 40 is a single-material encapsulation layer with no internal layering interfaces, allowing light to propagate continuously within the adhesive layer. By defining the shapes of the first recess 411 and the second recess 421, light directly above the LED chip 301 can be diffused, and some light can be refracted into the gap region, thereby improving the uniformity of light output.

[0060] Please see Figure 3 In other embodiments, the encapsulation structure 40 includes a concave lens adhesive array 430 and a transparent filler adhesive layer 440. The concave lens adhesive array 430 includes a plurality of discretely distributed concave lens adhesive layers 431. Each concave lens adhesive layer 431 has a plurality of first recesses 411 formed on its surface away from the substrate 10. Each concave lens adhesive layer 431 is correspondingly disposed on and covers each LED chip 301. The transparent filler adhesive layer 440 fills the space between the plurality of concave lens adhesive layers 431. The transparent filler adhesive layer 440 has a plurality of second recesses 421 formed on its surface away from the substrate 10.

[0061] The aforementioned light source assembly, with encapsulation structure 40, consists of a concave lens adhesive layer 431 and a transparent filler adhesive layer 440. The concave lens adhesive layer 431 diffuses the light directly above the LED chip 301 into lateral light, while the transparent filler adhesive layer 440 provides a flat light-emitting surface and reduces interface reflection. Together with the first recess 411 and the second recess 421, they can efficiently guide light to the gap region of the LED chip 301, significantly suppressing bright spots and filling dark areas at ultra-thin light mixing distances.

[0062] In some of these embodiments, such as Figure 3 As shown, the absolute value of the difference between the refractive index of the transparent filler layer 440 and the refractive index of the concave lens adhesive layer 431 is no greater than 0.1. It should be noted that the refractive index of the transparent filler layer 440 and the refractive index of the concave lens adhesive layer 431 can be the same or different. By making their refractive indices as close as possible, unexpected refraction and Fresnel reflection losses at the adhesive layer interface can be effectively suppressed, ensuring that light can propagate stably along a predetermined path. Preferably, the absolute value of the difference between the refractive index of the transparent filler layer 440 and the refractive index of the concave lens adhesive layer 431 is greater than 0 and less than or equal to 0.1.

[0063] Furthermore, the difference between the refractive index of the transparent filler layer 440 and the refractive index of the concave lens adhesive layer 431 can be greater than 0, equal to 0, or less than 0. As an example, the difference between the refractive index of the transparent filler layer 440 and the refractive index of the concave lens adhesive layer 431 can be 0.1, 0.02, 0, -0.08, -0.1, or any value within the range defined by any two of the above points as endpoints. Preferably, the refractive index of the transparent filler layer 440 is less than the refractive index of the concave lens adhesive layer 431.

[0064] It is understandable that when the difference in refractive index between the transparent filler layer 440 and the concave lens layer 431 is not zero, light will be refracted at the interface. By appropriately selecting the difference in refractive index, the outgoing direction of the light can be further controlled. Furthermore, when the refractive index of the transparent filler layer 440 is less than that of the concave lens layer 431, the light will be further deflected at a larger angle, thereby guiding the light energy to the gap area between the LED chips 301.

[0065] Optionally, the opening diameter of each first recess 411 is 1.8 to 2.2 times the height of the package structure 40. As an example, the opening diameter of the first recess 411 is 1.8, 1.9, 2.02, 2.14, or 2.2 times the height of the package structure 40, or any value within the range formed by any two of the above values ​​as endpoints. By setting this range of opening diameters for the first recess 411, the light directly above the LED chip 301 can be diffused over a larger lateral range, further effectively reducing the peak brightness of the central bright spot.

[0066] Optionally, the depth of each first recess 411 is 0.4 to 0.6 times the height of the packaging structure 40. As an example, the depth of the first recess 411 is 0.4, 0.5, 0.52, 0.54, or 0.6 times the height of the packaging structure 40, or any value within the range defined by any two of the above values ​​as endpoints. By setting this depth range of the first recess 411, the angle of light divergence can be adjusted, allowing the light intensity from directly above to diffuse evenly in all directions, further improving the uniformity of light emission.

[0067] Optionally, the diameter of each first recess 411 at half the depth below the recess opening is 0.6 to 0.9 times the height of the packaging structure 40. As an example, the diameter of the first recess 411 at half the recess depth is 0.6, 0.62, 0.74, 0.86, or 0.9 times the height of the packaging structure 40, or any value within the range defined by any two of the above points as endpoints. By setting this diameter range of the first recess 411 at half the depth, the slope of the recess sidewall can be matched with the light incident angle, improving light divergence efficiency while reducing total internal reflection loss.

[0068] It is understandable that this ratio range allows the light directly above the LED chip 301 to undergo moderate refraction and diffusion at the recessed interface, effectively reducing the peak brightness of the central bright spot, while avoiding light loss caused by excessive divergence or total reflection.

[0069] In some embodiments, the height of the packaging structure 40 is 0.4 to 1 mm.

[0070] Furthermore, the raw materials for preparing the encapsulation structure 40 include a two-component addition-curing thermosetting silicone.

[0071] Optionally, the raw material for preparing the encapsulation structure 40 has a viscosity of 1000~5000 mPa·s and a thixotropic index of 1.0~2.5 at 25±1℃. As an example, the viscosity of the raw material for preparing the encapsulation structure 40 at 25±1℃ is 1000, 2000, 2400, 3600, or 5000 mPa·s, or any value within the range defined by any two of the above points as endpoints. It can be understood that this viscosity range gives the adhesive good self-leveling properties, enabling it to fully fill the gaps between the LED chips 301 and form a flat upper surface.

[0072] In this application, the thixotropic index is defined as the index at a shear rate of 1 s⁻¹. -1 and 10 s -1 After measuring the viscosity under the specified conditions, the viscosity was measured at a low shear rate (1 s⁻¹). -1 Viscosity at the specified temperature divided by the high shear rate (10 s⁻¹) -1 The ratio obtained from the viscosity at )

[0073] In some embodiments, the light source assembly further includes a white ink layer 20, which is disposed in the gap between adjacent LED chips 301 on the substrate 10 and located between the substrate 10 and the package structure 40. Because a white ink layer is further disposed between the substrate 10 and the package structure 40, when the light emitted from the LED chip 301 passes through the large-angle light rays in the recess and the large-angle light rays formed after reflection, it undergoes multiple reflections between the white ink layer and the upper surface of the package structure, and finally transmits out from the upper surface of the package structure. This process disperses the light emission position, significantly improving the brightness of the gap area between the LED chips 301, thereby further improving the uniformity of light emission.

[0074] In some of these embodiments, such as Figure 2 As shown in optical path L1, the small-angle light emitted by LED chip 301 (with an angle between its angle and the normal of the upper surface of the package structure 40) forms a large incident angle on the recessed surface of the first recess 411 directly above the corresponding LED. Therefore, the light is reflected on the recessed surface of the first recess 411, effectively reducing the local brightness directly above the LED chip. After being reflected by the upper surface of the package structure 40 and the white ink layer 20, it is incident on the recessed surface of the second recess 421, forming a small-angle incident angle. After transmission, it effectively increases the local brightness directly above the gap area between adjacent LED chips 301. At the same time, as shown in optical path L2, the large-angle light emitted by LED chip 301 forms a small-angle incident angle on the recessed surface of the second recess 421. Therefore, it can also increase the local brightness directly above the gap area between adjacent LED chips 301 after transmission.

[0075] In some embodiments, the white ink layer 20 has a reflectivity greater than 85%.

[0076] The present invention also provides a method for fabricating the above-mentioned light source component with a dual-recessed array, comprising the following steps:

[0077] S10. A plurality of discretely distributed LED chips 301 are formed on the substrate 10 to obtain an LED array 30.

[0078] S20. An encapsulation structure 40 is formed on each LED chip 301. The encapsulation structure 40 covers each LED chip 301 and fills the gaps between the multiple LED chips 301. A plurality of first recesses 411 and a plurality of second recesses 421 are formed on the surface of the encapsulation structure 40 away from the substrate 10. Each first recess 411 is provided corresponding to each LED chip 301, and each second recess 421 is provided corresponding to the gaps between the LED chips 301.

[0079] In some embodiments, step S10 further includes forming a plurality of LED chips 301 arranged in rows and columns on the substrate 10 to obtain an LED array 30.

[0080] In some embodiments, step S20 further includes: filling the gaps between LED chips 301 with adhesive, leveling it, molding it with a mold, and then curing it to form an encapsulation structure 40 with the first recess 411 at the position corresponding to the LED chip 301 and the second recess 421 at the position corresponding to the gap between the LED chips 301.

[0081] In some embodiments, step S20 further includes: forming an encapsulation structure 40 with the first recess 411 described above and a second recess 421 formed at the geometric center of the rectangular area enclosed by two adjacent rows and two adjacent columns of LED chips 301 at the location corresponding to the LED chip 301. Further, the raw material for preparing the encapsulation structure 40 includes a two-component addition-curing thermosetting silicone. Further, the curing conditions are: first baking at 75℃~85℃ for 30~40 min, then baking at 145℃~155℃ for 1~2 h.

[0082] In some embodiments, prior to S10, the above-described preparation method further includes the following steps: a white ink layer 20 is formed on the substrate 10, with gaps left for solder paste printing. Correspondingly, the LED chip 301 in S10 is disposed on the solder paste on the surface of the substrate 10. Further, the encapsulation structure 40 fills the white ink layer 20, covers each LED chip 301, and fills the gaps between the multiple LED chips 301.

[0083] See Figure 3 In some embodiments, concave lens adhesive can be applied to the LED chip 301 first, and after a first curing, a concave lens adhesive layer 431 can be formed. Then, transparent filler adhesive can be applied to the gap area between adjacent concave lens adhesive layers 431, and after a second curing, a transparent filler adhesive layer 440 can be formed.

[0084] This invention also provides a backlight module, including any of the above-described light source components, or a light source component prepared by the above-described method.

[0085] Optionally, the backlight module may also include a diffuser plate disposed on the side of the packaging structure away from the substrate.

[0086] The backlight module described above significantly improves light uniformity due to the use of a light source component, and can achieve a uniform surface light source with a smaller light mixing distance (e.g., less than 1 mm). Therefore, the overall thickness can be reduced, and the number of optical films such as diffusers and prisms can be reduced, thereby reducing costs and assembly complexity.

[0087] Furthermore, embodiments of the present invention also provide a display device, including the light source component described above, the light source component prepared by the above method, or the backlight module described above.

[0088] Therefore, the aforementioned display device, due to the use of this backlight module, has a thinner overall thickness, higher display uniformity, and lower power consumption, making it suitable for ultra-thin screen designs.

[0089] The following are specific examples.

[0090] Example 1: A backlight module and its preparation method.

[0091] The backlight module includes a light source assembly and a diffuser plate.

[0092] The fabrication method of the above-mentioned backlight module is as follows:

[0093] S10: A white ink layer 20 is provided on the substrate 10, and gaps are reserved for solder paste printing. Multiple discretely distributed LED chips 301 are formed on the solder paste to obtain an LED array 30.

[0094] S20: Encapsulating adhesive is applied to the gaps between multiple LED chips 301, covering each LED chip 301 and filling the gaps between them. The mixture is then left to stand for 30 minutes to achieve self-leveling. Multiple first recesses 411 and multiple second recesses 421 are formed on the surface of the encapsulating adhesive away from the substrate 10 using a mold with a predetermined contour. Each first recess 411 corresponds to each LED chip 301, and each second recess 421 corresponds to the gaps between the LED chips 301. The above components are baked at 80°C for 30 minutes and then at 150°C for 1 hour to cure, thus obtaining the encapsulation structure 40. The raw material used to prepare the encapsulating adhesive has a refractive index of 1.41, a viscosity of 3700 mPa·s at 25±1°C, and a thixotropic index of 1.8 (at a shear rate of 1 s). -1 and 10 s -1 The viscosity ratio measured below), its raw material is filler adhesive BYW-S480.

[0095] S30: The diffuser plate is placed on the side of the packaging structure 40 away from the substrate and is in contact with the side of the packaging structure 40 away from the substrate.

[0096] The backlight module thus manufactured has a packaging structure 40 with a height of 0.6 mm; the opening diameter of each first recess 411 is 2.0 times the height of the packaging structure 40, the recess depth is 0.5 times the height of the packaging structure 40, and the diameter at half the depth of the recess opening is 0.75 times the height of the packaging structure; the opening diameter of each second recess 421 is 3.25 times the height of the packaging structure 40; the recess depth is 0.65 times the height of the packaging structure 40; and the diameter at half the recess depth is 1.65 times the height of the packaging structure 40.

[0097] The diffuser plate in the backlight module is disposed on the side of the encapsulation structure 40 away from the substrate and is in contact with the side of the encapsulation structure 40 away from the substrate. Since the height of the encapsulation structure 40 is 0.6 mm, the light mixing distance of the backlight module is also 0.6 mm.

[0098] In this backlight module, the small-angle light emitted by each LED chip 301 is reflected by the surface of each first recess 411. A significant portion of this light undergoes several reflections between the surface of the encapsulation structure 40 (away from the substrate 10) and the white ink layer 20 before exiting, thus dispersing the light emission position and significantly reducing the bright spots above each LED chip 301. Simultaneously, the large-angle light emitted directly from each LED chip 301, or the light that has undergone several reflections between the surface of the encapsulation structure 40 (away from the substrate 10) and the white ink layer 20, transmits a significant portion when incident on the surface of the second recess 421. Therefore, the brightness of the area above the gap between adjacent LED chips 301 is significantly improved. This backlight module achieves good light uniformity even with a relatively small mixing distance.

[0099] Example 2: A backlight module and its preparation method.

[0100] The backlight module includes a light source assembly and a diffuser plate, which are basically the same as those in Example 1, except that the fabrication steps of the light source assembly are different, as detailed below. The fabrication method of the light source assembly is as follows:

[0101] S10: A white ink layer 20 is provided on the substrate 10, and gaps are reserved for solder paste printing. Multiple discretely distributed LED chips 301 are formed on the solder paste to obtain an LED array 30.

[0102] S21. Apply adhesive to each LED chip 301, naturally forming a first recess 411 on the side away from the substrate 10. Bake the above component at 150°C for 1 hour to perform the first curing, forming a concave lens adhesive layer 431, thus obtaining a concave lens adhesive array 430. The height of the concave lens adhesive layer 431 is 0.6 mm. The opening diameter of each first recess 411 is 2.0 times the height of the concave lens adhesive layer 431, the recess depth is 0.5 times the height of the concave lens adhesive layer 431, and the diameter at half the depth below the recess opening is 0.75 times the height of the concave lens adhesive layer 431. The raw material used to prepare the concave lens adhesive has a refractive index of 1.47, a viscosity of 9400 mPa·s at 25±1°C, and a thixotropic index of 5.3 (at a shear rate of 1 s⁻¹). -1 and 10 s -1 The viscosity ratio measured below), its raw material is KMT-0884M LED silicone encapsulant;

[0103] S22: A point of transparent filler adhesive is applied to the gap area between multiple LED chips 301, filling the gap area between all adjacent concave lens adhesives. The mixture is left to stand for 30 minutes to achieve self-leveling. Multiple second recesses 421 are formed on the surface of the transparent filler adhesive away from the substrate 10 using a mold with a predetermined contour. Each second recess 421 corresponds to a gap between the LED chips 301. The above components are baked at 80°C for 30 minutes, and then baked at 150°C for 1 hour for a second curing, resulting in a transparent filler adhesive layer 440. The concave lens adhesive array 430 and the transparent filler adhesive layer 440 together constitute the encapsulation structure 40. The height of the transparent filler adhesive layer 440 is also 0.6 mm. The opening diameter of each second recess 421 is 3.25 times the height of the transparent filler adhesive layer 440; the recess depth is 0.65 times the height of the transparent filler adhesive layer 440; and the diameter at half the recess depth is 1.65 times the height of the transparent filler adhesive layer 440. The raw material used to prepare the transparent filler adhesive has a refractive index of 1.41, a viscosity of 3700 mPa·s at 25±1℃, and a thixotropic index of 1.8 (at a shear rate of 1 s⁻¹). -1 and 10 s -1 The viscosity ratio measured below), its raw material is filler adhesive BYW-S480.

[0104] S30: The diffuser plate is placed on the side of the packaging structure 40 away from the substrate and is in contact with the side of the packaging structure 40 away from the substrate.

[0105] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A light source assembly with a dual-recessed array, characterized in that, The package includes a substrate, an LED array, and a packaging structure. The LED array includes a plurality of discretely distributed LED chips, which are disposed on the substrate. The packaging structure is disposed on the substrate and covers each LED chip and fills the gaps between the plurality of LED chips. The surface of the packaging structure away from the substrate has a plurality of first recesses and a plurality of second recesses. Each first recess corresponds to each LED chip and forms a first recess array. Each of the second recesses is arranged corresponding to the gap between the LED chips, forming a second recess array.

2. The light source assembly according to claim 1, characterized in that, The LED array contains multiple LED chips arranged in multiple rows and columns, and the second recess is provided at the geometric center of the rectangular area enclosed by two adjacent rows and two adjacent columns of LED chips.

3. The light source assembly according to claim 1, characterized in that, One or more of the following conditions must be met: (1) The opening diameter of each of the second recesses is 3 to 3.5 times the height of the encapsulation structure; (2) The depth of each of the second recesses is 0.5 to 0.8 times the height of the packaging structure; (3) The diameter at half the depth of each of the second recesses is 1.5 to 1.8 times the height of the packaging structure.

4. The light source assembly according to any one of claims 1 to 3, characterized in that, The encapsulation structure is a uniform encapsulation layer. The encapsulation structure is disposed on the substrate and covers each of the LED chips and fills the gaps between the LED chips. The surface of the encapsulation structure away from the substrate has a plurality of first recesses corresponding to each of the LED chips and a plurality of second recesses corresponding to the gaps between the LED chips.

5. The light source assembly according to any one of claims 1 to 3, characterized in that, The encapsulation structure includes a concave lens adhesive array and a transparent filler adhesive layer. The concave lens adhesive array includes a plurality of discretely distributed concave lens adhesive layers. Each concave lens adhesive layer has a plurality of first recesses formed on its surface away from the substrate. Each concave lens adhesive layer is correspondingly disposed on and covers each LED chip. The transparent filler adhesive layer fills the spaces between the plurality of concave lens adhesive layers. The transparent filler adhesive layer has a plurality of second recesses formed on its surface away from the substrate.

6. The light source assembly according to claim 5, characterized in that, The absolute value of the difference between the refractive index of the transparent filler layer and the refractive index of the concave lens layer is not greater than 0.

1.

7. The light source assembly according to any one of claims 1 to 3, characterized in that, One or more of the following conditions must be met: (1) The opening diameter of each of the first recesses is 1.8 to 2.2 times the height of the packaging structure; (2) The depth of each of the first recesses is 0.4 to 0.6 times the height of the packaging structure; (3) The diameter of each of the first recesses at a depth of half the depth below the recess opening is 0.6 to 0.9 times the height of the encapsulation structure; (4) The height of the packaging structure is 0.4~1 mm.

8. The light source assembly according to any one of claims 1 to 3, characterized in that, The light source assembly also includes a white ink layer, which is disposed on the substrate at the gap between adjacent LED chips and located between the substrate and the packaging structure.

9. The light source assembly according to claim 8, characterized in that, The white ink layer has a reflectivity greater than 85%.

10. A method for fabricating a light source assembly with a dual-recessed array, characterized in that, Includes the following steps: An LED array is fabricated by forming multiple discretely distributed LED chips on a substrate. A package structure is formed on each of the LED chips; The encapsulation structure covers each of the LED chips and fills the gaps between the LED chips. The surface of the encapsulation structure away from the substrate has a plurality of first recesses and a plurality of second recesses. Each of the first recesses is disposed corresponding to each of the LED chips, forming a first recess array. Each of the second recesses is arranged corresponding to the gap between the LED chips, forming a second recess array.

11. A backlight module, characterized in that, Includes the light source assembly as described in any one of claims 1 to 9 or the light source assembly prepared by the preparation method described in claim 10.

12. The backlight module according to claim 11, characterized in that, The backlight module also includes a diffuser plate, which is disposed on the side of the packaging structure away from the substrate.

13. A display device, characterized in that, It includes the light source assembly according to any one of claims 1 to 9, the light source assembly prepared by the preparation method according to claim 10, or the backlight module according to any one of claims 11 to 12.

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