CSP backlight source double-layer packaging structure and processing method thereof

Abstract

The invention relates to the technical field of backlight display equipment, and provides a CSP backlight source double-layer packaging structure and a processing method thereof, and the CSP backlight source double-layer packaging structure comprises a substrate which is provided with a light-emitting circuit; the CSP comprises a packaging structure and a light-emitting chip arranged in the packaging structure, the light-emitting chip is arranged on the substrate and electrically connected with the light-emitting circuit, and the light-emitting chip is a Mini LED; the packaging adhesive layer comprises a first adhesive layer and a second adhesive layer, the first adhesive layer is connected to the substrate in a sealed mode and wraps the CSP package, a first gap is formed between the first adhesive layer and the CSP package, the second adhesive layer is connected to the substrate, and the first gap is filled with the second adhesive layer and sealed by the second adhesive layer; the first glue layer and the second glue layer are transparent shells formed through glue dispensing and curing of a glue dispenser. According to the CSP backlight source double-layer packaging structure, air gaps between the first adhesive layer and the CSP packaging and between the first adhesive layer and the second adhesive layer can be eliminated, meanwhile, the risk that the CSP backlight source is eroded by water vapor is eliminated, and the effect of improving the light emitting quality of the CSP backlight source is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of backlight display devices, and more specifically, to a CSP backlight source double-layer packaging structure and a processing method thereof. Background Art

[0002] CSP backlight (Chip Scale Package Backlight Unit) is an advanced backlight technology, mainly used in LED display panels. Compared with traditional LED backlights, CSP technology has the advantage of miniaturization. The core advantage of CSP technology lies in its extremely small package size. The CSP package is almost the same size as the light-emitting chip itself, hence the name "chip scale package". This allows the backlight to be designed more compactly, helping to reduce the thickness of the display device and achieve an ultra-thin design. Therefore, CSP backlights are widely used in high-end smartphones, tablets, laptops, HDTVs, and various devices that require high-definition displays.

[0003] At present, when using CSP backlight, a layer of lens is usually set on the outside of CSP package. The lens can not only protect the CSP package, but also diffuse the light emitted by the CSP package to obtain a larger luminous angle. In the related art, the light output quality of CSP backlight is low. For example, there is an installation gap between the lens and the CSP package, and water vapor can easily enter the installation gap, thereby reducing the light output quality of the CSP backlight.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the invention

[0005] The purpose of the present application is to propose a CSP backlight source double-layer packaging structure and a processing method thereof, so as to solve the technical problem of low light output quality of the CSP backlight source in the prior art.

[0006] To achieve the above objectives, the present application provides a CSP backlight source double-layer packaging structure in a first aspect, comprising:

[0007] A substrate, on which a light-emitting circuit is provided;

[0008] CSP package, comprising a package structure and a light-emitting chip arranged in the package structure, wherein the light-emitting chip is arranged on the substrate and electrically connected to the light-emitting circuit, and the light-emitting chip is a Mini LED;

[0009] The encapsulation glue layer comprises a first glue layer and a second glue layer, wherein the first glue layer is sealed and connected to the substrate and covers the CSP package, a first gap is formed between the first glue layer and the CSP package, and the second glue layer is connected to the substrate and fills and seals the first gap;

[0010] The first adhesive layer and the second adhesive layer are both transparent shells formed by curing through adhesive dispensing by an adhesive dispenser, and the first adhesive layer is a hemispherical structure.

[0011] Furthermore, the refractive index of the first adhesive layer is a, the refractive index of the second adhesive layer is b, and a<b.

[0012] Furthermore, the packaging glue layer also includes a self-focusing lens layer, and the self-focusing lens layer is sealed and connected between the first glue layer and the second glue layer.

[0013] In some embodiments, the self-focusing lens layer includes a first surface and a second surface, the first surface is sealed tightly to the first adhesive layer, the second surface is sealed tightly to the second adhesive layer, the refractive index of the self-focusing lens layer on the first surface is a, and the refractive index of the self-focusing lens layer on the second surface is b.

[0014] Furthermore, the encapsulation adhesive layer is an integrated structure, the interface between the first adhesive layer and the second adhesive layer is fused to each other to form a fusion layer, the refractive index of the fusion layer is c, a<c<b.

[0015] In some embodiments, the first adhesive layer and the second adhesive layer are cured adhesive layers, and the cured adhesive includes silicone or epoxy resin.

[0016] Furthermore, the packaging structure includes a conversion layer, which at least covers the light-emitting front side of the light-emitting chip, and is used to convert and mix the light emitted by the light-emitting chip to emit white light.

[0017] In some embodiments, the packaging structure further includes a scattering layer, wherein the scattering layer is a silica gel layer with diffusion powder disposed therein, and the scattering layer covers the conversion layer.

[0018] Furthermore, the packaging structure also includes a reflective layer, which is a transparent silicone layer with diffusion powder inside. The proportion of the diffusion powder in the reflective layer is greater than the proportion of the diffusion powder in the scattering layer, and the reflective layer covers the scattering layer.

[0019] A second aspect of the present application provides a method for processing a CSP backlight double-layer packaging structure, which is applied to the above-mentioned CSP backlight double-layer packaging structure, comprising the following steps:

[0020] Step S1: fixing the light-emitting chip on the substrate, and connecting the light-emitting chip to the light-emitting circuit;

[0021] Step S2: After the light-emitting chip is fixed, a glue layer is covered on the light-emitting chip by molding, and the glue layer is cured at a set temperature to form the packaging structure;

[0022] Step S3: cutting off the packaging structure between and on both sides of adjacent light-emitting chips through a cutting process to form a single CSP package;

[0023] Step S4: Covering the surrounding and top of the CSP package with curing glue by dispensing, and after the curing glue seals and covers the CSP package, curing it at a set temperature to form the second glue layer;

[0024] Step S5: Covering the first adhesive layer with curing adhesive around and on top by dispensing, and after the curing adhesive seals and covers the second adhesive layer, curing it at a set temperature to form the first adhesive layer.

[0025] The CSP backlight double-layer packaging structure and processing method provided by the present application have at least the following beneficial effects:

[0026] The double-layer packaging structure of the CSP backlight source can eliminate the air gap between the first glue layer and the CSP package, and between the first glue layer and the second glue layer, while eliminating the risk of the CSP backlight source being corroded by water vapor, thereby improving the light output quality of the CSP backlight source.

[0027] A self-focusing lens layer is arranged between the first adhesive layer and the second adhesive layer, and the light can be refracted gradually between the first adhesive layer and the second adhesive layer, which is equivalent to reducing the magnitude of the difference in the refractive index change of the encapsulation adhesive layer, thereby reducing the risk of total internal reflection of the light, reducing the light loss during the propagation of the light in the encapsulation adhesive layer, improving the light collection efficiency, and thus improving the light output quality of the CSP backlight source.

[0028] After the fusion layer is set, the encapsulation glue layer eliminates the interface between the first glue layer and the second glue layer, which can eliminate the interface refraction of light and reduce the light loss when the light propagates in the encapsulation glue layer, thereby achieving the effect of improving the light output quality of the CSP backlight source. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A schematic diagram of a structure of a CSP backlight double-layer packaging structure provided in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of another structure of the double-layer packaging structure of a CSP backlight source provided in an embodiment of the present application;

[0032] Figure 3 A schematic diagram of another structure of the CSP backlight double-layer packaging structure provided in the embodiment of the present application;

[0033] Figure 4 This is a flow chart of a method for processing a double-layer packaging structure of a CSP backlight source provided in an embodiment of the present application.

[0034] Among them, the reference numerals in the figure are:

[0035] 1. Substrate;

[0036] 2. Light-emitting chip;

[0037] 3. Packaging structure; 31. Conversion layer; 32. Scattering layer; 33. Reflective layer;

[0038] 4. Encapsulation glue layer;

[0039] 41. First adhesive layer;

[0040] 42. Second adhesive layer;

[0041] 43. self-focusing lens layer; 431. first surface; 432. second surface;

[0042] 44. Fusion layer. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly or indirectly located on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and cannot be understood as limitations on the present technical solution. The terms "first" and "second" are only used for the convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0045] In a first aspect of the present application, a CSP backlight double-layer packaging structure is provided. The CSP backlight double-layer packaging structure of an embodiment of the present application is described below with reference to the accompanying drawings.

[0046] See also Figure 1 , Figure 1 The schematic diagram of the structure of the double-layer packaging structure of the CSP backlight source of the present application is shown, including a substrate 1, a CSP package and a packaging adhesive layer 4, wherein the CSP package is used to emit white light, and the packaging adhesive layer 4 is used to protect the CSP package and expand the light output angle of the CSP package.

[0047] Specifically, see Figure 1 A light-emitting circuit is provided on the substrate 1. The CSP package includes a packaging structure 3 and a light-emitting chip 2 arranged in the packaging structure 3. The light-emitting chip 2 is arranged on the substrate 1 and electrically connected to the light-emitting circuit. The light-emitting chip 2 is a MiniLED. The light-emitting chip 2 emits light after power is turned on.

[0048] The encapsulation glue layer 4 includes a first glue layer 41 and a second glue layer 42. The first glue layer 41 is sealed and connected to the substrate 1 and covers the CSP package. There is a first gap between the first glue layer 41 and the CSP package. The second glue layer 42 is connected to the substrate 1. The second glue layer 42 fills and seals the first gap. The first glue layer 41 and the second glue layer 42 are both transparent shells formed by dispensing and curing with a dispensing machine. The first glue layer 41 is a hemispherical structure.

[0049] It should be noted that the glue dispenser is a highly specialized automated equipment, which is mainly used to accurately control the distribution and coating of fluids (such as colloids, adhesives, paints, sealants, etc.). In this embodiment, when processing the encapsulation glue layer 4, the colloid is first melted into a fluid state, and then the glue is dispensed by the glue dispenser. That is to say, the first glue layer 41 and the second glue layer 42 are first in a fluid or semi-solid state during the formation process, and then the gap between them is eliminated by the flow of the fluid, and finally solidified to form a transparent shell.

[0050] Eliminating the gap is specifically reflected in that: during the dispensing process, the fluid colloid used to form the second glue layer 42 can completely cover the CSP package during the flow process, and there is no gap between the formed second glue layer 42 and the CSP package, thereby achieving sealing of the CSP package. Similarly, the fluid colloid used to form the first glue layer 41 can completely cover the second glue layer 42 during the flow process, and there is no gap between the formed first glue layer 41 and the second glue layer 42, thereby achieving sealing of the second glue layer 42. Finally, the first glue layer 41 and the second glue layer 42 are cured to obtain a solid packaging glue layer 4.

[0051] Thus, the air gap between the first adhesive layer 41 and the CSP package and between the first adhesive layer 41 and the second adhesive layer 42 can be eliminated, and the risk of the CSP backlight being corroded by water vapor can be eliminated, thereby improving the light output quality of the CSP backlight.

[0052] It should be noted that, in the prior art, the lens used to protect the CSP package is a pre-made injection molded shell. Although the final state of the first adhesive layer 41 is a solid shell, during the manufacturing process, the installation accuracy of the injection molded shell is low, and bubbles are easily left between the injection molded shell and the second adhesive layer 42, affecting the light output quality of the CSP backlight source.

[0053] Specifically, if the first adhesive layer 41 is replaced with a hemispherical injection molded shell, it is equivalent to buckling the injection molded shell onto the second adhesive layer 42 after the second adhesive layer 42 is formed. Since the injection molded shell is hemispherical with an inner concave surface, during the buckling process, the inner concave surface of the injection molded shell needs to be buckled toward the second adhesive layer 42. Since the injection molded shell is already a hard solid shell, there is no state in which the injection molded shell flows relative to the second adhesive layer 42. The inner concave surface of the injection molded shell can only be filled by relying on the flow deformation of the second adhesive layer 42. However, the air in the inner concave low point area of ​​the injection molded shell is difficult to be removed from between the second adhesive layer 42 and the injection molded shell. If it cannot be discharged in time, bubbles will remain between the injection molded shell and the second adhesive layer 42. The manufacturing and processing is very difficult, and it is difficult to completely eliminate all gaps between the injection molded shell and the second adhesive layer 42.

[0054] Different from the cooperation mode of injection-molded shell and adhesive layer, in this embodiment, the first adhesive layer 41 and the second adhesive layer 42 gradually cover the second adhesive layer 42 through the mutual flow of fluids, and the gap between the first adhesive layer 41 and the second adhesive layer 42 can be completely eliminated, the processing difficulty is small, and the processed CSP backlight source can provide better light output quality.

[0055] Furthermore, the core function of the glue dispenser is to accurately drop the fluid onto the surface or inside of the target product in a set path, shape and amount, so as to achieve efficient and accurate glue dispensing. That is, the glue dispenser can control the shapes of the first glue layer 41 and the second glue layer 42 while forming the first glue layer 41 and the second glue layer 42. In some embodiments, when the second glue layer 42 is formed by glue dispensing, the glue dispensing path of the glue dispenser can be controlled to obtain the second glue layer 42 with a hemispherical outer surface. Similarly, the hemispherical first glue layer 41 can also be obtained.

[0056] Furthermore, after the first adhesive layer 41 is cured, it can be grinded and polished by a sander to modify the shape of the first adhesive layer 41 and improve the shape accuracy of the first adhesive layer 41 after processing.

[0057] Furthermore, the light emitting chip 2 in a conventional CSP backlight source emits light toward the front. The light emitted toward the front passes through the gap between the lens and the light emitting chip 2, and then passes through the prefabricated injection-molded lens and is refracted, thereby achieving the effect of expanding the light emitting angle. However, the light emitting angle that can be expanded in this way is limited.

[0058] To this end, in some embodiments, in order to further improve the light output angle of the CSP backlight source, the refractive index of the first glue layer 41 is a, and the refractive index of the second glue layer 42 is b, and a<b. That is, the refractive index of the first glue layer 41 is less than the refractive index of the second glue layer 42, and the refractive index of the first glue layer 41 and the second glue layer 42 are both greater than that of air. In this way, after the light of the light-emitting chip 2 is emitted, it can be refracted once when passing through the second glue layer 42, thereby expanding the light-emitting angle once, and can be refracted a second time when entering the first glue layer 41 from the second glue layer 42, thereby expanding the light-emitting angle once again. Therefore, the second glue layer 42 can not only fill the gap between the first glue layer 41 and the CSP package, but also play the role of additionally expanding the light-emitting angle, while preventing water vapor from invading and expanding the light-emitting angle, thereby achieving the effect of improving the light output quality of the CSP backlight source.

[0059] In some embodiments, see Figure 2 The encapsulation glue layer 4 also includes a self-focusing lens layer 43, which is sealed between the first glue layer 41 and the second glue layer 42. The self-focusing lens layer 43 can reduce the light loss at the interface between the first glue layer 41 and the second glue layer 42, thereby achieving the effect of improving the light output quality of the CSP backlight source.

[0060] It should be noted that, although there is no gap between the first adhesive layer 41 and the second adhesive layer 42, the first adhesive layer 41 and the second adhesive layer 42 have different refractive indices. When light enters the first adhesive layer 41 from the second adhesive layer 42, total internal reflection is likely to occur, which will cause a certain amount of light loss. In order to effectively reduce the light loss caused by total internal reflection and improve the light extraction efficiency as much as possible, it is necessary to reduce the refractive index change difference between the first adhesive layer 41 and the second adhesive layer 42. For this purpose, the present embodiment sets a self-focusing lens layer 43 between the first adhesive layer 41 and the second adhesive layer 42.

[0061] The self-focusing lens layer 43 is also called a gradient refractive index lens, which is a cylindrical optical lens with a radial gradient refractive index distribution of the internal material. Unlike a traditional convex lens, when light propagates in a traditional convex lens, although the light is changed in direction, it still propagates in a straight line, while the gradient refractive index lens not only changes the direction of the light, but also allows the light to propagate in a sinusoidal function along the central axis.

[0062] When the self-focusing lens layer 43 is arranged between the first adhesive layer 41 and the second adhesive layer 42, the light can be refracted gradually between the first adhesive layer 41 and the second adhesive layer 42, which is equivalent to reducing the magnitude of the difference in the refractive index change of the encapsulation adhesive layer 4, thereby reducing the risk of total internal reflection of the light, reducing the light loss during the propagation of the light in the encapsulation adhesive layer 4, improving the light collection efficiency, and thus improving the light output quality of the CSP backlight source.

[0063] Further, see Figure 2 The self-focusing lens layer 43 includes a first surface 431 and a second surface 432. The first surface 431 is sealed tightly to the first adhesive layer 41, and the second surface 432 is sealed tightly to the second adhesive layer 42. The refractive index of the self-focusing lens layer 43 on the first surface 431 is a, and the refractive index of the self-focusing lens layer 43 on the second surface 432 is b.

[0064] That is to say, the refractive index inside the self-focusing lens layer 43 changes gradually between a and b, so that the refractive index does not change when the light enters the self-focusing lens layer 43 from the second adhesive layer 42, and the refractive index does not change when the light enters the first adhesive layer 41 from the self-focusing lens layer 43, so total internal reflection will not occur. At the same time, since the refractive index inside the self-focusing lens layer 43 changes gradually, total internal reflection will not occur in the self-focusing lens layer 43. Therefore, total internal reflection will not occur in the packaging adhesive layer 4, further reducing the light loss when the light propagates in the packaging adhesive layer 4, and improving the light output quality of the CSP backlight source.

[0065] When processing the packaging glue layer 4, a glue dispenser is used to dispense glue on the CSP package to form a second glue layer 42. The fluid colloid used to form the second glue layer 42 completely covers the CSP package during the flow process to achieve sealing of the CSP package. Then, the self-focusing lens layer 43 is buckled onto the second glue layer 42, and then a glue dispenser is used to dispense glue on the self-focusing lens layer 43 to form a first glue layer 41. Finally, the first glue layer 41 and the second glue layer 42 are cured to obtain a solid packaging glue layer 4.

[0066] Furthermore, the light loss in the encapsulation adhesive layer 4 is not entirely caused by total internal reflection. The light loss is also caused when the light undergoes interfacial refraction at the interface between the first adhesive layer 41 and the second adhesive layer 42. This is because, although there is no gap between the first adhesive layer 41 and the second adhesive layer 42, there is an interface between the first adhesive layer 41 and the second adhesive layer 42. When the light enters the first adhesive layer 41 from the second adhesive layer 42, it is easy to undergo interfacial refraction at the interface position, which will also cause a certain amount of light loss and reduce the light output quality of the CSP backlight source. For this reason, the present embodiment also provides a method for eliminating interfacial refraction, that is, the first adhesive layer 41 and the second adhesive layer 42 are constructed into an integrated structure that is fused with each other.

[0067] Specifically, see Figure 3The packaging adhesive layer 4 is an integrated structure, and the interface between the first adhesive layer 41 and the second adhesive layer 42 is fused to form a fusion layer 44 . The refractive index of the fusion layer 44 is c, and a<c<b.

[0068] When processing the packaging glue layer 4, first melt the first glue layer 41 and the second glue layer 42 into a fluid state, wherein the first glue layer 41 is formed by a first colloid, and the second glue layer 42 is formed by a second colloid. Exemplarily, the first colloid is QGel 920 (silicone gel), which is a high-refractive index organic silicone gel with a refractive index of about 1.49; the second colloid is silicone gel for LED packaging, which usually has a higher refractive index of about 1.54.

[0069] Then, a preset amount of the second colloid is placed in the pressure barrel of the dispensing machine, and then a preset amount of the first colloid is placed in the pressure barrel, and then the first colloid and the second colloid are left to stand for a preset time to stabilize the state of the first colloid and the second colloid. At this time, the first colloid and the second colloid are both in a fluid state. Due to the different material densities of the first colloid and the second colloid, the first colloid and the second colloid will be separated into layers in the pressure barrel, but a part of them will fuse with each other at the contact position of the first colloid and the second colloid, and this part is the fused colloid used to form the fused layer 44, and the refractive index of the fused colloid is between the refractive index of the first colloid and the second colloid.

[0070] Finally, a dispensing machine is used to dispense glue on the CSP package. As the first colloid and the second colloid flow out, a second glue layer 42, a fusion layer 44 and a first glue layer 41 are sequentially formed on the CSP package, and there is no interface between the second glue layer 42, the fusion layer 44 and the first glue layer 41, and the encapsulation glue layer 4 is constructed into an integrated structure. The encapsulation glue layer 4 eliminates the interface between the first glue layer 41 and the second glue layer 42, can eliminate the interface refraction of light, reduce the light loss when the light propagates in the encapsulation glue layer 4, and achieve the effect of improving the light output quality of the CSP backlight source.

[0071] At the same time, when the light propagates in the packaging glue layer 4, it passes through the second glue layer 42, the fusion layer 44 and the first glue layer 41 in sequence. Since the refractive index of the fusion layer 44 is between the refractive index of the first colloid and the second colloid, the formed fusion layer 44 can reduce the difference in the refractive index change between the first glue layer 41 and the second glue layer 42, thereby reducing the risk of total internal reflection of the light in the packaging glue layer 4, reducing light loss, and further improving the light output quality of the CSP backlight source.

[0072] In some embodiments, the first adhesive layer 41 and the second adhesive layer 42 are curing adhesive layers. As mentioned in the above embodiments, the first adhesive layer 41 can be QGel 920 (silicone gel), and the second adhesive layer 42 can be silicone for LED packaging, which are two silicone materials with different refractive indices. Of course, in addition to silicone, the curing adhesive can also be epoxy resin. For example, the first adhesive layer 41 uses bisphenol A epoxy resin, whose refractive index is about 1.53; the second adhesive layer 42 uses Thomas high refractive index transparent epoxy resin THO5020, whose refractive index is about 1.581.

[0073] It should be noted that the lens layer formed by the first adhesive layer 41 and the second adhesive layer 42 is different from the lens layer formed by the injection molded shell. Specifically, the manufacturing process of the cured adhesive layer and the injection molded shell is different. The injection molded shell needs to be pre-made and is already a hard shell when processing the CSP backlight source, while the cured adhesive layer has a process of solidifying from a fluid to a hard shell when processing the CSP backlight source, which also makes the gap between the first adhesive layer 41 and the second adhesive layer 42 smaller, and can achieve the effect of completely eliminating the gap. Secondly, under the condition of the same light transmittance, the cost of using silicone and epoxy resin is lower, which can reduce the production cost of the CSP backlight source.

[0074] Further, see Figure 1-Figure 3 The packaging structure 3 includes a conversion layer 31, which at least covers the light-emitting front side of the light-emitting chip 2. The conversion layer 31 is used to convert and mix the light emitted by the light-emitting chip 2 to emit white light.

[0075] The conversion layer 31 includes a green light conversion layer and a red light conversion layer. The green light conversion layer faces the light-emitting front of the light-emitting chip 2, the red light conversion layer covers the green light conversion layer, and the green light conversion layer is located between the light-emitting chip 2 and the red light conversion layer. Of course, the positions of the red light conversion layer and the green light conversion layer can also be swapped, the red light conversion layer faces the light-emitting front of the light-emitting chip 2, the green light conversion layer covers the red light conversion layer, and the red light conversion layer is located between the light-emitting chip 2 and the green light conversion layer.

[0076] After the blue light chip emits blue light, the blue light excites green light when passing through the green light conversion layer, and excites red light when passing through the red light conversion layer, which are then mixed to form white light.

[0077] In some embodiments, a red light phosphor is disposed in the red light conversion layer, and a green light phosphor is disposed in the green light conversion layer, including but not limited to fluoride phosphors, such as KSF phosphors and KGF phosphors.

[0078] Further, see Figure 1-Figure 3 The packaging structure 3 further includes a scattering layer 32 . The scattering layer 32 is a silica gel layer with diffusion powder inside. The scattering layer 32 covers the conversion layer 31 .

[0079] After entering the scattering layer 32 , the light is converted by the diffusion powder so that more light is emitted from the side of the light emitting chip 2 , thereby increasing the light emitting angle of the packaged chip.

[0080] In some embodiments, see Figure 1-Figure 3 The packaging structure 3 also includes a reflective layer 33 , which is a transparent silicone layer with diffusion powder inside. The proportion of the diffusion powder in the reflective layer 33 is greater than the proportion of the diffusion powder in the scattering layer 32 , and the reflective layer 33 covers the scattering layer 32 .

[0081] The diffusion powder is mainly used to scatter the light. When the concentration of the diffusion powder is very high, it will also reflect the light, which is also the working principle of the scattering layer 32 and the reflective layer 33. After the reflective layer 33 is set, part of the light entering the reflective layer 33 will return to the scattering layer 32, and this part of the light will be scattered again and emitted more from the side of the packaged chip, thereby further increasing the light emitting angle of the packaged chip.

[0082] After the scattering layer 32 and the reflective layer 33 are provided, the light emitting angle of the packaged chip is improved. Based on this, the light area formed after diffusion through the first adhesive layer and the second adhesive layer will also be larger, thereby improving the light output quality of the CSP backlight source.

[0083] In some embodiments, the diffusion powder includes any one of silicon dioxide solid particles and titanium dioxide solid particles or a combination thereof.

[0084] In a second aspect of the present application, a processing method for a CSP backlight double-layer packaging structure is provided, which is applied to the CSP backlight double-layer packaging structure in the above-mentioned embodiment. Figure 4 , including the following steps:

[0085] Step S1: fixing the light emitting chip 2 on the substrate 1, and connecting the light emitting chip 2 with the light emitting circuit;

[0086] Step S2: After the light emitting chip 2 is fixed, a glue layer is covered on the light emitting chip 2 by molding, and the glue layer is cured at a set temperature to form a packaging structure 3;

[0087] Step S3: cutting off the packaging structure 3 between and on both sides of adjacent light-emitting chips 2 through a cutting process to form a single CSP package;

[0088] Step S4: Covering the CSP package with curing glue around and above the CSP package by dispensing. After the curing glue seals and covers the CSP package, it is cured at a set temperature to form a second glue layer 42;

[0089] Step S5: Cover the first adhesive layer 41 with curing adhesive around and on top by dispensing. After the curing adhesive seals and covers the second adhesive layer 42 , it is cured at a set temperature to form the first adhesive layer 41 .

[0090] Further, in step S4, when processing the second glue layer 42, the second glue layer 42 is first melted into a fluid state, wherein the second glue layer 42 is formed by a second colloid, and illustratively, the second colloid is silicone for LED packaging. Then a preset amount of the second colloid is placed in a pressure barrel of a glue dispenser. Finally, the glue dispenser is used to dispense glue on the CSP package, and as the second colloid flows out, a second glue layer 42 is formed on the CSP package.

[0091] Further, in step S5, when processing the first adhesive layer 41, the first adhesive layer 41 is melted into a fluid state, wherein the first adhesive layer 41 is formed by a first colloid, illustratively, the first colloid is QGel 920 (silicone gel). Then a preset amount of the first colloid is put into the pressure barrel of the dispensing machine. Finally, the dispensing machine is used to dispense glue on the second adhesive layer 42, and the first colloid flows on the second adhesive layer 42 and seals the second adhesive layer 42, and forms the first adhesive layer 41 after curing.

[0092] Furthermore, step S4 and step S5 may be combined, that is, the first adhesive layer 41 and the second adhesive layer 42 may be processed and formed simultaneously.

[0093] Specifically, the first adhesive layer 41 and the second adhesive layer 42 are first melted into a fluid state, wherein the first adhesive layer 41 is formed by a first colloid, and the second adhesive layer 42 is formed by a second colloid. Exemplarily, the first colloid is QGel 920 (silicone gel), and the second colloid is silicone for LED packaging.

[0094] Then, a preset amount of the second colloid is placed into the pressure barrel of the dispensing machine, and then a preset amount of the first colloid is placed into the pressure barrel, and then left to stand for a preset time to stabilize the states of the first colloid and the second colloid, so that the first colloid and the second colloid can be separated into layers in the pressure barrel, and a part of the contact position between the first colloid and the second colloid can be fused with each other, and this part is the fusion colloid used to form the fusion layer 44.

[0095] Finally, a dispensing machine is used to dispense glue on the CSP package. As the first colloid and the second colloid flow out, a second glue layer 42, a fusion layer 44 and a first glue layer 41 are sequentially formed on the CSP package, and the package glue layer 4 is constructed into an integrated structure.

[0096] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A CSP backlight double-layer packaging structure, characterized in that: include: A substrate, on which a light-emitting circuit is provided; CSP package, comprising a package structure and a light-emitting chip arranged in the package structure, wherein the light-emitting chip is arranged on the substrate and electrically connected to the light-emitting circuit, and the light-emitting chip is a Mini LED; The encapsulation glue layer comprises a first glue layer and a second glue layer, wherein the first glue layer is sealed and connected to the substrate and covers the CSP package, a first gap is formed between the first glue layer and the CSP package, and the second glue layer is connected to the substrate and fills and seals the first gap; The first adhesive layer and the second adhesive layer are both transparent shells formed by curing by adhesive dispensing machine, and the first adhesive layer is a hemispherical structure.

2. The CSP backlight double-layer packaging structure according to claim 1, characterized in that: The refractive index of the first adhesive layer is a, the refractive index of the second adhesive layer is b, and a<b.

3. The CSP backlight double-layer packaging structure according to claim 2, characterized in that: The packaging glue layer also includes a self-focusing lens layer, and the self-focusing lens layer is sealed and connected between the first glue layer and the second glue layer.

4. The CSP backlight double-layer packaging structure according to claim 3, characterized in that: The self-focusing lens layer includes a first surface and a second surface, the first surface is sealed tightly to the first adhesive layer, and the second surface is sealed tightly to the second adhesive layer. The refractive index of the self-focusing lens layer on the first surface is a, and the refractive index of the self-focusing lens layer on the second surface is b.

5. The CSP backlight double-layer packaging structure according to claim 2, characterized in that: The packaging adhesive layer is an integrated structure, and the interfaces of the first adhesive layer and the second adhesive layer are fused to form a fusion layer. The refractive index of the fusion layer is c, and a<c<b.

6. The CSP backlight double-layer packaging structure according to any one of claims 1 to 5, characterized in that: The first adhesive layer and the second adhesive layer are curing adhesive layers, and the curing adhesive includes silicone and epoxy resin.

7. The CSP backlight double-layer packaging structure according to claim 6, characterized in that: The packaging structure comprises a conversion layer, which at least covers the light-emitting front side of the light-emitting chip. The conversion layer is used to convert and mix the light emitted by the light-emitting chip to emit white light.

8. The CSP backlight double-layer packaging structure according to claim 7, characterized in that: The packaging structure further includes a scattering layer, which is a silica gel layer with diffusion powder inside, and the scattering layer covers the conversion layer.

9. The CSP backlight double-layer packaging structure according to claim 8, characterized in that: The packaging structure further includes a reflective layer, which is a transparent silicone layer with diffusion powder inside. The proportion of the diffusion powder in the reflective layer is greater than the proportion of the diffusion powder in the scattering layer. The reflective layer covers the scattering layer.

10. A method for processing a CSP backlight double-layer packaging structure, applied to the CSP backlight double-layer packaging structure of claim 9, characterized in that: The following steps are involved: Step S1: fixing the light-emitting chip on the substrate, and connecting the light-emitting chip to the light-emitting circuit; Step S2: After the light-emitting chip is fixed, a glue layer is covered on the light-emitting chip by molding, and the glue layer is cured at a set temperature to form the packaging structure; Step S3: cutting off the packaging structure between and on both sides of adjacent light-emitting chips through a cutting process to form a single CSP package; Step S4: Covering the surrounding and top of the CSP package with curing glue by dispensing, and after the curing glue seals and covers the CSP package, curing it at a set temperature to form the second glue layer; Step S5: Covering the first adhesive layer with curing adhesive around and on top by dispensing, and after the curing adhesive seals and covers the second adhesive layer, curing it at a set temperature to form the first adhesive layer.

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