CSP backlight source double-layer packaging structure

Abstract

The utility model relates to the technical field of backlight display equipment, and provides a CSP (Chip Scale Package) backlight source double-layer packaging structure, which comprises a substrate 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] This application relates to the field of backlight display device technology, and more specifically, to a CSP backlight dual-layer packaging structure. Background Technology

[0002] CSP (Chip Scale Package Backlight Unit) is an advanced backlight technology primarily used in LED display panels. Compared to traditional LED backlights, CSP technology offers the advantage of miniaturization. The core advantage of CSP 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 packaging." This allows for more compact backlight designs, contributing to reduced display device thickness and enabling ultra-thin designs. Therefore, CSP backlights are widely used in high-end smartphones, tablets, laptops, high-definition televisions, and various devices requiring high-definition displays.

[0003] Currently, when using CSP backlights, a lens is typically placed outside the CSP package. The lens protects the CSP package and also diffuses the light emitted from it to achieve a wider emission angle. However, in related technologies, CSP backlights suffer from low light emission quality. For example, there is a gap between the lens and the CSP package, allowing moisture to easily enter and reduce the light emission quality.

[0004] Therefore, existing technologies still need improvement and development. Utility Model Content

[0005] The purpose of this application is to propose a dual-layer packaging structure for CSP backlights to solve the technical problem of low light output quality of existing CSP backlights.

[0006] To achieve the above objectives, the first aspect of this application provides a CSP backlight dual-layer packaging structure, comprising:

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

[0008] CSP packaging includes a packaging structure and a light-emitting chip disposed within the packaging structure. The light-emitting chip is disposed on the substrate and electrically connected to the light-emitting circuit. The light-emitting chip is a Mini LED.

[0009] An encapsulating adhesive layer includes a first adhesive layer and a second adhesive layer. The first adhesive layer is sealed and connected to the substrate and covers the CSP package. There is a first gap between the first adhesive layer and the CSP package. The second adhesive layer is connected to the substrate and fills and seals the first gap.

[0010] Both the first adhesive layer and the second adhesive layer are transparent shells formed by dispensing and curing with a dispensing machine, and the first adhesive layer has a hemispherical structure.

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

[0012] Furthermore, the encapsulating adhesive layer also includes a self-focusing lens layer, which is sealed between the first adhesive layer and the second adhesive layer.

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

[0014] Furthermore, the encapsulating adhesive layer is an integral structure, and the interface between the first adhesive layer and the second adhesive layer is fused together to form a fusion layer, wherein the refractive index of the fusion layer is c, and 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 and epoxy resin.

[0016] Furthermore, the packaging structure includes a conversion layer that covers at least the 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.

[0017] In some embodiments, the encapsulation structure further includes a scattering layer, which is a silicone layer with diffuser powder inside, and the scattering layer covers the conversion layer.

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

[0019] Furthermore, the diffusion powder includes any one or a combination of silica solid particles and titanium dioxide solid particles.

[0020] The beneficial effects of the CSP backlight dual-layer packaging structure provided in this application are at least as follows: the CSP backlight dual-layer packaging structure can eliminate the air gap between the first adhesive layer and the CSP package, as well as between the first adhesive layer and the second adhesive layer, and at the same time eliminate the risk of the CSP backlight being corroded by moisture, thereby improving the light output quality of the CSP backlight.

[0021] A self-focusing lens layer is placed between the first and second adhesive layers, allowing light to be refracted gradually between them. This reduces the difference in refractive index between the encapsulation layers, thereby reducing the risk of total internal reflection, minimizing light loss during propagation, improving light extraction efficiency, and ultimately enhancing the light output quality of the CSP backlight.

[0022] After the encapsulating adhesive layer is fused, the interface between the first adhesive layer and the second adhesive layer is eliminated, which can eliminate the interface refraction of light and reduce the light loss when the light propagates in the encapsulating adhesive layer, thereby improving the light output quality of the CSP backlight. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of a CSP backlight dual-layer packaging structure provided in an embodiment of this application;

[0025] Figure 2 Another schematic diagram of the CSP backlight dual-layer packaging structure provided in the embodiments of this application;

[0026] Figure 3 This is another schematic diagram of the CSP backlight dual-layer packaging structure provided in the embodiments of this application.

[0027] The following are the labeling elements in the figure:

[0028] 1. Substrate;

[0029] 2. Light-emitting chip;

[0030] 3. Encapsulation structure; 31. Conversion layer; 32. Scattering layer; 33. Reflective layer;

[0031] 4. Encapsulating adhesive layer;

[0032] 41. First adhesive layer;

[0033] 42. Second adhesive layer;

[0034] 43. Self-focusing lens layer; 431. First surface; 432. Second surface;

[0035] 44. Fusion Layer. Detailed Implementation

[0036] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0037] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it may be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it may be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positions based on the accompanying drawings, and are for ease of description only, and should not be construed as limiting the technical solution. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "A plurality" means two or more, unless otherwise explicitly defined.

[0038] The first aspect of this application provides a CSP backlight dual-layer packaging structure. The CSP backlight dual-layer packaging structure of this application is described below with reference to the accompanying drawings.

[0039] Please see Figure 1 , Figure 1 The diagram shows a structural schematic of the dual-layer CSP backlight packaging structure of this application, 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 emission angle of the CSP package.

[0040] Specifically, see Figure 1 The substrate 1 is provided with a light-emitting circuit. The CSP package includes a package structure 3 and a light-emitting chip 2 disposed in the package structure 3. The light-emitting chip 2 is disposed on the substrate 1 and electrically connected to the light-emitting circuit. The light-emitting chip 2 is a MiniLED and emits light after being powered on.

[0041] The encapsulation adhesive layer 4 includes a first adhesive layer 41 and a second adhesive layer 42. The first adhesive layer 41 is sealed and connected to the substrate 1 and covers the CSP package. There is a first gap between the first adhesive layer 41 and the CSP package. The second adhesive layer 42 is connected to the substrate 1 and fills and seals the first gap. Both the first adhesive layer 41 and the second adhesive layer 42 are transparent shells formed by dispensing and curing with a dispensing machine. The first adhesive layer 41 has a hemispherical structure.

[0042] It should be noted that a dispensing machine is a highly specialized automated device, mainly used for the precise control of the distribution and coating of fluids (such as colloids, adhesives, paints, sealants, etc.). In this embodiment, when processing the encapsulating adhesive layer 4, the colloid is first melted into a fluid state, and then dispensed using a dispensing machine. That is to say, both the first adhesive layer 41 and the second adhesive layer 42 are initially in a fluid or semi-solid state during the formation process, and then the gaps between them are eliminated by the flow of the fluid, finally curing to form a transparent shell.

[0043] Eliminating gaps is specifically manifested in the following ways: During the dispensing process, the fluid adhesive used to form the second adhesive layer 42 can completely cover the CSP package during the flow process, and there is no gap between the formed second adhesive layer 42 and the CSP package, thus achieving a seal for the CSP package. Similarly, the fluid adhesive used to form the first adhesive layer 41 can completely cover the second adhesive layer 42 during the flow process, and there is no gap between the formed first adhesive layer 41 and the second adhesive layer 42, thus achieving a seal for the second adhesive layer 42. Finally, the first adhesive layer 41 and the second adhesive layer 42 are cured to obtain a solid encapsulation adhesive layer 4.

[0044] This eliminates the air gaps between the first adhesive layer 41 and the CSP package, as well as between the first adhesive layer 41 and the second adhesive layer 42, thereby eliminating the risk of moisture erosion to the CSP backlight and improving the light output quality of the CSP backlight.

[0045] 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 first adhesive layer 41 is ultimately a solid shell, the installation accuracy of the injection-molded shell is low during the manufacturing process, and air bubbles are easily left between the injection-molded shell and the second adhesive layer 42, which affects the light output quality of the CSP backlight.

[0046] Specifically, if a hemispherical injection-molded shell is used to replace the first adhesive layer 41, it is equivalent to attaching the injection-molded shell onto the second adhesive layer 42 after the second adhesive layer 42 is formed. Since the injection-molded shell is a hemispherical shape with a concave surface, during the fastening process, the concave surface of the injection-molded shell needs to face the second adhesive layer 42. Since the injection-molded shell is already a hard solid shell, there is no flow state between the injection-molded shell and the second adhesive layer 42. It can only rely on the flow deformation of the second adhesive layer 42 to fill the concave surface of the injection-molded shell. However, it is difficult for the air in the concave low point area of ​​the injection-molded shell to be expelled from between the second adhesive layer 42 and the injection-molded shell. If it cannot be expelled in time, air bubbles will remain between the injection-molded shell and the second adhesive layer 42, making the manufacturing process very difficult and making it difficult to completely eliminate all the gaps between the injection-molded shell and the second adhesive layer 42.

[0047] Unlike the way the injection-molded shell and the adhesive layer are joined, in this embodiment, the first adhesive layer 41 and the second adhesive layer 42 are connected by the mutual flow of fluid. The first adhesive layer 41 gradually covers the second adhesive layer 42, which can completely eliminate the gap between the first adhesive layer 41 and the second adhesive layer 42. The processing is less difficult, and the processed CSP backlight can provide better light output quality.

[0048] Furthermore, the core function of a dispensing machine is to accurately dispense fluid onto the surface or interior of a target product along a set path, shape, and amount, achieving efficient and precise dispensing operations. In other words, the dispensing machine can control the shapes of the first adhesive layer 41 and the second adhesive layer 42 while simultaneously forming them. In some embodiments, controlling the dispensing path of the dispensing machine when forming the second adhesive layer 42 can result in a second adhesive layer 42 with a hemispherical outer surface; similarly, a hemispherical first adhesive layer 41 can also be obtained.

[0049] Furthermore, after the first adhesive layer 41 has cured, it can be polished using a sanding machine to correct its shape and improve the shape accuracy of the first adhesive layer 41 after processing.

[0050] Furthermore, in a conventional CSP backlight, the light-emitting chip 2 emits light directly forward. The light emitted directly forward passes through the gap between the lens and the light-emitting chip 2, and then passes through the pre-molded lens and is refracted, thereby expanding the light-emitting angle. However, the light-emitting angle that can be expanded in this way is limited.

[0051] Therefore, in some embodiments, to further improve the light emission angle of the CSP backlight, the refractive index of the first adhesive layer 41 is 'a', and the refractive index of the second adhesive layer 42 is 'b', where 'a' < 'b'. That is, the refractive index of the first adhesive layer 41 is less than the refractive index of the second adhesive layer 42, and both the refractive indices of the first adhesive layer 41 and the second adhesive layer 42 are greater than those of air. Thus, after the light from the light-emitting chip 2 is emitted, it undergoes one refraction when passing through the second adhesive layer 42, expanding the light emission angle once. When it enters the first adhesive layer 41 from the second adhesive layer 42, it undergoes a second refraction, further expanding the light emission angle. Therefore, the second adhesive layer 42 not only fills the gap between the first adhesive layer 41 and the CSP package but also additionally expands the light emission angle, preventing moisture intrusion while expanding the light emission angle, thereby improving the light emission quality of the CSP backlight.

[0052] In some implementations, see Figure 2The encapsulating adhesive layer 4 also includes a self-focusing lens layer 43, which is sealed between the first adhesive layer 41 and the second adhesive layer 42. The self-focusing lens layer 43 can reduce light loss at the interface of the first adhesive layer 41 and the second adhesive layer 42, thereby improving the light output quality of the CSP backlight.

[0053] 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 some light loss. In order to effectively reduce the light loss caused by total internal reflection and maximize the light extraction efficiency, it is necessary to reduce the difference in refractive index between the first adhesive layer 41 and the second adhesive layer 42. For this purpose, this embodiment provides a self-focusing lens layer 43 between the first adhesive layer 41 and the second adhesive layer 42.

[0054] The self-focusing lens layer 43, also known as a graded-index lens, is a cylindrical optical lens in which the refractive index of the internal material gradually changes radially. Unlike a traditional convex lens, where light propagates in a straight line even though its direction is changed, a graded-index lens not only changes the direction of light but also makes it propagate sinusoidally along the central axis.

[0055] When a self-focusing lens layer 43 is provided between the first adhesive layer 41 and the second adhesive layer 42, light can be gradually refracted between the first adhesive layer 41 and the second adhesive layer 42, which is equivalent to reducing the magnitude of the difference in refractive index change of the encapsulation adhesive layer 4. This can reduce the risk of total internal reflection of light, reduce the light loss of light propagating in the encapsulation adhesive layer 4, improve the light extraction efficiency, and thus improve the light output quality of the CSP backlight.

[0056] 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 and tightly attached to the first adhesive layer 41, and the second surface 432 is sealed and tightly attached 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.

[0057] In other words, the refractive index inside the self-focusing lens layer 43 gradually changes between a and b. Thus, there is no change in refractive index when light enters the self-focusing lens layer 43 from the second adhesive layer 42, and there is also no change in refractive index when light enters the first adhesive layer 41 from the self-focusing lens layer 43. Therefore, total internal reflection does not occur. Furthermore, because the refractive index inside the self-focusing lens layer 43 is gradually changed, total internal reflection also does not occur within the self-focusing lens layer 43. Therefore, no total internal reflection occurs within the encapsulation adhesive layer 4, further reducing light loss during propagation within the encapsulation adhesive layer 4 and improving the light output quality of the CSP backlight.

[0058] During the processing of the encapsulation adhesive layer 4, a dispensing machine is used to dispense adhesive onto the CSP package to form a second adhesive layer 42. The fluid adhesive used to form the second adhesive layer 42 completely covers the CSP package during its flow, achieving a seal for the CSP package. Then, the self-focusing lens layer 43 is attached to the second adhesive layer 42, and the dispensing machine is used to dispense adhesive onto the self-focusing lens layer 43 to form a first adhesive layer 41. Finally, the first adhesive layer 41 and the second adhesive layer 42 are cured to obtain a solid encapsulation adhesive layer 4.

[0059] Furthermore, the light loss within the encapsulating adhesive layer 4 is not entirely due to total internal reflection. Light loss also occurs when light undergoes interface 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 them. When light enters the first adhesive layer 41 from the second adhesive layer 42, interface refraction easily occurs at the interface, which also causes a certain amount of light loss and reduces the light output quality of the CSP backlight. To address this, this embodiment also provides a method to eliminate interface refraction, namely, constructing the first adhesive layer 41 and the second adhesive layer 42 into a fused, integrated structure.

[0060] Specifically, see Figure 3 The encapsulating adhesive layer 4 is an integral structure. The interface between the first adhesive layer 41 and the second adhesive layer 42 is fused together to form a fusion layer 44. The refractive index of the fusion layer 44 is c, where a < c < b.

[0061] When processing the encapsulating adhesive layer 4, the first adhesive layer 41 and the second adhesive layer 42 are first melted into a fluid state. The material used to form the first adhesive layer 41 is the first colloid, and the material used to form the second adhesive layer 42 is the second colloid. For example, the first colloid is QGel 920 (silicone gel), which is a high refractive index silicone gel with a refractive index of approximately 1.49; the second colloid is silicone for LED encapsulation, which typically has a high refractive index of approximately 1.54.

[0062] Then, a preset amount of the second colloid is placed into the pressure tank of the dispensing machine, followed by a preset amount of the first colloid. The mixture is then allowed to stand for a preset time to allow both colloids to stabilize. At this point, both the first and second colloids are in a fluid state. Due to the difference in material density between the first and second colloids, they will separate into layers within the pressure tank. However, at the point where the first and second colloids meet, they will partially fuse together. This fused colloid is used to form the fusion layer 44, and the refractive index of the fused colloid is between that of the first and second colloids.

[0063] Finally, a dispensing machine is used to apply adhesive to the CSP package. As the first and second adhesives flow out, a second adhesive layer 42, a fusion layer 44, and a first adhesive layer 41 are sequentially formed on the CSP package. There is no longer an interface between the second adhesive layer 42, the fusion layer 44, and the first adhesive layer 41, and the encapsulation adhesive layer 4 forms a single, integrated structure. The encapsulation adhesive layer 4 eliminates the interface between the first adhesive layer 41 and the second adhesive layer 42, thereby eliminating interface refraction of light and reducing light loss during propagation within the encapsulation adhesive layer 4, ultimately improving the light output quality of the CSP backlight.

[0064] Meanwhile, when light propagates within the encapsulating adhesive layer 4, it passes sequentially through the second adhesive layer 42, the fusion layer 44, and the first adhesive layer 41. Since the refractive index of the fusion layer 44 is between that of the first and second adhesive layers, the fusion layer 44 can reduce the difference in refractive index between the first and second adhesive layers 41 and 42, thereby reducing the risk of total internal reflection within the encapsulating adhesive layer 4, reducing light loss, and further improving the light output quality of the CSP backlight.

[0065] In some embodiments, the first adhesive layer 41 and the second adhesive layer 42 are cured 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 encapsulation. These are two silicone materials with different refractive indices. Of course, in addition to silicone, the cured adhesive can also be epoxy resin. For example, the first adhesive layer 41 is made of bisphenol A type epoxy resin with a refractive index of approximately 1.53; the second adhesive layer 42 is made of Thomas high refractive index transparent epoxy resin THO5020 with a refractive index of approximately 1.581.

[0066] 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 processes of the cured adhesive layer and the injection-molded shell are different. The injection-molded shell needs to be pre-made and is already a rigid shell when processing the CSP backlight. In contrast, the cured adhesive layer undergoes a process of curing from a fluid to a rigid shell during the processing of the CSP backlight. This results in a smaller gap between the first adhesive layer 41 and the second adhesive layer 42, achieving the effect of completely eliminating the gap. Secondly, under the same light transmittance, the cost of using silicone and epoxy resin is lower, which can reduce the production cost of the CSP backlight.

[0067] Further, see Figures 1-3 The encapsulation structure 3 includes a conversion layer 31, which covers at least the 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.

[0068] The conversion layer 31 includes a green light conversion layer and a red light conversion layer. The green light conversion layer faces the front of the light-emitting chip 2, and the red light conversion layer covers the green light conversion layer, with the green light conversion layer located between the light-emitting chip 2 and the red light conversion layer. Alternatively, the positions of the red and green light conversion layers can be reversed, with the red light conversion layer facing the front of the light-emitting chip 2, the green light conversion layer covering the red light conversion layer, and the red light conversion layer located between the light-emitting chip 2 and the green light conversion layer.

[0069] After the blue light chip emits blue light, the blue light is excited into green light when it passes through the green light conversion layer, and then excited into red light when it passes through the red light conversion layer, and then mixed to form white light.

[0070] In some embodiments, a red phosphor is disposed in the red light conversion layer and a green phosphor is disposed in the green light conversion layer, including but not limited to fluoride phosphors, such as KSF phosphor and KGF phosphor.

[0071] Further, see Figures 1-3 The encapsulation structure 3 also includes a scattering layer 32, which is a silicone layer with diffuser powder inside, and the scattering layer 32 covers the conversion layer 31.

[0072] After entering the scattering layer 32, the light undergoes path conversion through the diffuser 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.

[0073] In some implementations, see Figures 1-3 The encapsulation structure 3 also includes a reflective layer 33, which is a transparent silicone layer with diffuser powder inside. The proportion of diffuser powder in the reflective layer 33 is greater than the proportion of diffuser powder in the scattering layer 32. The reflective layer 33 covers the scattering layer 32.

[0074] The diffuser powder is mainly used to scatter light. When the concentration of the diffuser powder is high, it can also reflect light. This is the working principle of the scattering layer 32 and the reflective layer 33. After the reflective layer 33 is set, some 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 emission angle of the packaged chip.

[0075] By setting the scattering layer 32 and the reflective layer 33, the light emission angle of the packaged chip is improved. Based on this, the light area formed after diffusion through the first and second adhesive layers will also be larger, improving the light emission quality of the CSP backlight.

[0076] In some embodiments, the diffusion powder includes any one or a combination of silica solid particles, titanium dioxide solid particles, or other similar materials.

[0077] This application also provides a method for processing a CSP backlight dual-layer packaging structure, applied to the CSP backlight dual-layer packaging structure in the above embodiments, including the following steps:

[0078] Step S1: Fix the light-emitting chip 2 on the substrate 1 and connect the light-emitting chip 2 to the light-emitting circuit;

[0079] Step S2: After fixing the light-emitting chip 2, an adhesive layer is covered on the light-emitting chip 2 by molding, and then cured at a set temperature to form the encapsulation structure 3;

[0080] Step S3: The packaging structure 3 between and on both sides of adjacent light-emitting chips 2 is removed by a cutting process to form a single CSP package;

[0081] Step S4: Apply curing adhesive around and above the CSP package by dispensing. After the curing adhesive seals and covers the CSP package, cure it at a set temperature to form the second adhesive layer 42.

[0082] Step S5: Apply curing adhesive around and above the first adhesive layer 41 by dispensing. After the curing adhesive seals and covers the second adhesive layer 42, cure it at a set temperature to form the first adhesive layer 41.

[0083] Further, in step S4, when processing the second adhesive layer 42, the second adhesive layer 42 is first melted into a fluid state, wherein the material used to form the second adhesive layer 42 is a second colloid, exemplarily, the second colloid is silicone for LED encapsulation. Then, a preset amount of the second colloid is placed into the pressure tank of the dispensing machine. Finally, the dispensing machine is used to dispense the second colloid onto the CSP package, and as the second colloid flows out, the second adhesive layer 42 is formed on the CSP package.

[0084] Further, in step S5, when processing the first adhesive layer 41, the first adhesive layer 41 is melted into a fluid state, wherein the material used to form the first adhesive layer 41 is a first colloid, exemplarily QGel 920 (silicone gel). Then, a preset amount of the first colloid is placed into the pressure tank of the dispensing machine. Finally, the dispensing machine is used to dispense the first colloid onto the second adhesive layer 42, allowing it to flow and seal the second adhesive layer 42, and forming the first adhesive layer 41 after curing.

[0085] Furthermore, steps S4 and S5 can be combined, that is, the first adhesive layer 41 and the second adhesive layer 42 are processed and formed simultaneously.

[0086] Specifically, the first adhesive layer 41 and the second adhesive layer 42 are first melted into a fluid state. The first adhesive layer 41 is formed by a first colloid, and the second adhesive layer 42 is formed by a second colloid. For example, the first colloid is QGel 920 (silicone gel), and the second colloid is silicone for LED encapsulation.

[0087] Then, a preset amount of the second colloid is placed into the pressure tank of the dispensing machine, and a preset amount of the first colloid is placed into the pressure tank. Then, the mixture is left to stand for a preset time to allow the first and second colloids to stabilize, so that the first and second colloids will separate into layers in the pressure tank, and the contact points of the first and second colloids will fuse together. This part is the fusion colloid used to form the fusion layer 44.

[0088] Finally, a dispensing machine is used to dispense adhesive onto the CSP package. As the first adhesive and the second adhesive flow out, the second adhesive layer 42, the fusion layer 44 and the first adhesive layer 41 are sequentially formed on the CSP package, and the encapsulation adhesive layer 4 is constructed into an integral structure.

[0089] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A CSP backlight dual-layer packaging structure, characterized in that, include: A substrate, wherein a light-emitting circuit is provided on the substrate; CSP packaging includes a packaging structure and a light-emitting chip disposed within the packaging structure. The light-emitting chip is disposed on the substrate and electrically connected to the light-emitting circuit. The light-emitting chip is a Mini LED. An encapsulating adhesive layer includes a first adhesive layer and a second adhesive layer. The first adhesive layer is sealed and connected to the substrate and covers the CSP package. There is a first gap between the first adhesive layer and the CSP package. The second adhesive layer is connected to the substrate and fills and seals the first gap. Both the first adhesive layer and the second adhesive layer are transparent shells formed by dispensing and curing with a dispensing machine, and the first adhesive layer has a hemispherical structure. The refractive index of the first adhesive layer is a, and the refractive index of the second adhesive layer is b, where a < b; The encapsulating adhesive layer is an integral structure. The interface between the first adhesive layer and the second adhesive layer is fused together to form a fusion layer. The refractive index of the fusion layer is c, where a < c < b.

2. The CSP backlight dual-layer packaging structure according to claim 1, characterized in that, The encapsulating adhesive layer also includes a self-focusing lens layer, which is sealed between the first adhesive layer and the second adhesive layer.

3. The CSP backlight dual-layer packaging structure according to claim 2, characterized in that, The self-focusing lens layer includes a first surface and a second surface. The first surface is sealed and tightly attached to the first adhesive layer, and the second surface is sealed and tightly attached 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.

4. The CSP backlight dual-layer packaging structure according to any one of claims 1-3, characterized in that, The first adhesive layer and the second adhesive layer are cured adhesive layers.

5. The CSP backlight dual-layer packaging structure according to claim 4, characterized in that, The packaging structure includes a conversion layer that covers at least the 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.

6. The CSP backlight dual-layer packaging structure according to claim 5, characterized in that, The encapsulation structure further includes a scattering layer, which is a silicone layer with diffuser powder inside, and the scattering layer covers the conversion layer.

7. The CSP backlight dual-layer packaging structure according to claim 6, characterized in that, The encapsulation structure further includes a reflective layer, which is a transparent silicone layer with diffuser powder inside. The proportion of diffuser powder in the reflective layer is greater than the proportion of diffuser powder in the scattering layer, and the reflective layer covers the scattering layer.

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