CSP backlight source and display device
By using CSP backlight technology with near-ultraviolet light chips and composite fluorescent conversion layers, the problems of insufficient backlight color stability and color rendering performance in LED display solutions have been solved, achieving an improvement in the color rendering index of high color gamut white light and a reduction in cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHINEON BEIJING TECH
- Filing Date
- 2024-12-30
- Publication Date
- 2026-04-28
AI Technical Summary
In existing LED display solutions, the backlight has poor color stability and color rendering performance, especially the blue light-emitting chip, which emits light weakly in the red spectrum region and is easily affected by the operating current.
Near-ultraviolet light chips are used as light-emitting chips, and near-ultraviolet light is converted into white light through a composite fluorescence conversion layer, including at least two fluorescence conversion layers. CSP backlight is fabricated using chip-scale packaging (CSP) technology.
It improves the color stability and color rendering performance of the backlight, avoids the problem of weak light emission of blue light chips in the red spectrum region, reduces the impact on the operating current, and has a high color rendering index and low cost.
Smart Images
Figure CN224178538U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of display device backlight technology, and more particularly to a CSP backlight and display device. Background Technology
[0002] Currently, LED display solutions typically use blue light-emitting chips to excite quantum dots or phosphors to achieve white backlighting.
[0003] The light-emitting diodes in blue LED chips emit relatively weak light in the red spectrum region, and the color of the emitted light is affected by the operating current. They have disadvantages such as high color difference, low color rendering index, and poor color stability, which leads to poor color stability and poor color rendering performance of the backlight. Utility Model Content
[0004] In view of this, the present disclosure provides a CSP backlight and display device to solve the technical problems of poor color stability and poor color rendering performance of the backlight in the prior art.
[0005] To achieve the above objectives, the technical solution adopted in this disclosure is:
[0006] A first aspect of this disclosure provides a CSP backlight, comprising: a substrate including a light-emitting circuit; a light-emitting package disposed on the substrate and electrically connected to the light-emitting circuit, including a near-ultraviolet light chip and a composite fluorescence conversion layer stacked sequentially from bottom to top, the composite fluorescence conversion layer including at least two fluorescence conversion layers, the composite fluorescence conversion layer covering at least above the near-ultraviolet light chip, for converting and mixing the light emitted by the near-ultraviolet light chip to emit white light, the light-emitting package being fabricated using chip-scale packaging (CSP) technology; and a lens layer covering the light-emitting package without gaps.
[0007] In one embodiment, the near-ultraviolet light chip is a MiniLED near-ultraviolet light chip.
[0008] In one embodiment, the composite fluorescence conversion layer includes a blue fluorescence conversion layer, a green fluorescence conversion layer, and a red fluorescence conversion layer stacked sequentially from bottom to top.
[0009] In one embodiment, the lens layer includes a diffusion layer, a reflection layer, and a lens arranged sequentially from bottom to top.
[0010] In one embodiment, the diffusion layer is a white glue layer or a silicone layer containing diffusion powder; and / or, the reflective layer is a white glue layer or a silicone layer containing diffusion powder.
[0011] In one embodiment, the diffusion powder comprises silicon dioxide, titanium dioxide, or solid particles of a mixture of silicon dioxide and titanium dioxide.
[0012] In one embodiment, the CSP backlight further includes an optical diaphragm assembly disposed in the light emission direction of the light-emitting package.
[0013] In one embodiment, the interface between the light-emitting package and the diffusion layer is a plane, while the interface between the diffusion layer and the reflective layer, as well as the interface between the reflective layer and the lens, are curved surfaces, with the curved surfaces bulging away from the near-ultraviolet light chip.
[0014] In one embodiment, the excitation wavelength of the near-ultraviolet light chip is 355nm to 405nm.
[0015] A second aspect of this disclosure provides a display device, including a display panel and a CSP backlight as described above.
[0016] The beneficial effects of this disclosed embodiment compared with the prior art include: by using a near-ultraviolet light chip as the backlight chip, the problem of relatively weak light emission in the red spectrum region of the blue light chip and the influence of the operating current on the luminous color can be avoided, thereby improving the color stability and color rendering performance of the backlight. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of a CSP backlight provided in an embodiment of this disclosure;
[0019] Figure 2 This is a schematic diagram of another CSP backlight provided in an embodiment of this disclosure;
[0020] Figure 3 This is a schematic diagram of yet another CSP backlight provided in an embodiment of this disclosure;
[0021] Figure 4 This is a schematic diagram of another CSP backlight provided in the embodiments of this disclosure. Detailed Implementation
[0022] To make the technical problems, technical solutions, and beneficial effects to be solved by this disclosure clearer, the disclosure will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining this disclosure and are not intended to limit this disclosure.
[0023] 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.
[0024] The CSP backlight and display device according to embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. For ease of structural description, the following description will take a front-emitting backlight as an example, with the front side being the light emission direction.
[0025] Figure 1 This is a schematic diagram of a CSP backlight provided in an embodiment of this disclosure; Figure 2 This is a schematic diagram of another CSP backlight provided in an embodiment of this disclosure; Figure 3 This is a schematic diagram of yet another CSP backlight provided in this embodiment of the disclosure. Figure 4 This is a schematic diagram of another CSP backlight provided in the embodiments of this disclosure. The following is in conjunction with... Figures 1 to 4 Let's describe the CSP backlight and display device provided in the embodiments of this disclosure.
[0026] like Figures 1 to 3 As shown, the CSP (Chip Scale Package) backlight provided in this embodiment includes a substrate, a light-emitting package, and a lens layer. The light-emitting package is electrically connected to the circuit layer of the substrate and includes a near-ultraviolet (NIV) light chip and a composite fluorescence conversion layer stacked sequentially from bottom to top. The composite fluorescence conversion layer includes at least two different fluorescence conversion layers, and the composite fluorescence conversion layer covers at least the top of the NUV light chip. Stacking sequentially from bottom to top means stacking the composite fluorescence conversion layer on the front side of the NUV light chip.
[0027] Specifically, the substrate includes a circuit layer, which in turn includes a light-emitting circuit. The light-emitting package is electrically connected to the light-emitting circuit. The electrodes of the near-ultraviolet (NIUV) LED chip are soldered to the light-emitting circuit on the substrate, thus positioning the NIUV chip on the front surface of the substrate. The front surface of the NIUV chip is the primary light-emitting surface; therefore, it is defined as the front light-emitting side, and the surrounding sides of the NIUV chip are the light-emitting sides. The light-emitting package is disposed on the front surface of the substrate and electrically connected to the circuit layer. The light-emitting package can be soldered onto the substrate using a COB (Chip-On-Board) flip-chip process. The light-emitting package emits white light in the light-emitting direction. A lens layer is seamlessly covered on the light-emitting package, and the lens layer and the light-emitting package are seamlessly bonded, ensuring that each light-emitting package has a sufficient emission angle.
[0028] like Figure 1 As shown, an embodiment of this disclosure provides a CSP backlight including: a substrate 110, including a light-emitting circuit; a light-emitting package disposed on the substrate and electrically connected to the light-emitting circuit, including a near-ultraviolet light chip 121 and a composite fluorescence conversion layer 122 stacked from bottom to top, the composite fluorescence conversion layer 122 including a first fluorescence conversion layer 1221 and a second fluorescence conversion layer 1222 disposed from bottom to top, the composite fluorescence conversion layer at least covering the top of the near-ultraviolet light chip, used to convert and mix the light emitted by the near-ultraviolet light chip to emit white light, the light-emitting package is fabricated by CSP technology; and a lens layer 130, the lens layer covering the light-emitting package without gaps.
[0029] In one embodiment, the composite fluorescence conversion layer 122 is composed of a blue fluorescence conversion layer and a red-green mixed fluorescence conversion layer arranged sequentially from bottom to top. Specifically, the first fluorescence conversion layer 1221 can be a red-green mixed fluorescence conversion layer in which red phosphor and green phosphor are mixed in the encapsulating adhesive. Correspondingly, the second fluorescence conversion layer 1221 can be a blue fluorescence conversion layer in which blue phosphor is mixed in the encapsulating adhesive. When near-ultraviolet light emitted by the near-ultraviolet chip irradiates the first fluorescence conversion layer 1221, it can be converted into mixed light of red and green light. When this mixed light irradiates the second fluorescence conversion layer 1222, it can be converted into blue light. The mixed light, blue light and near-ultraviolet light are mixed together to form white light, thereby causing the light-emitting package to emit white light. In addition, the positions of the red-green mixed fluorescence conversion layer and the blue fluorescence conversion layer can be interchanged, that is, the composite fluorescence conversion layer 122 is composed of a blue fluorescence conversion layer and a red-green mixed fluorescence conversion layer arranged sequentially from bottom to top.
[0030] Similarly, the composite fluorescence conversion layer 122 can be composed of a red fluorescence conversion layer and a blue-green mixed fluorescence conversion layer arranged sequentially from bottom to top, or it can be composed of a blue-green mixed fluorescence conversion layer and a red fluorescence conversion layer arranged sequentially from bottom to top. The blue-green mixed fluorescence conversion layer can be formed by mixing blue phosphor and green phosphor in the encapsulating adhesive, and correspondingly, the red fluorescence conversion layer can be formed by mixing red phosphor in the encapsulating adhesive.
[0031] Similarly, the composite fluorescence conversion layer 122 can be composed of a green fluorescence conversion layer and a red-blue mixed fluorescence conversion layer arranged sequentially from bottom to top, or it can be composed of a red-blue mixed fluorescence conversion layer and a green fluorescence conversion layer arranged sequentially from bottom to top. The red-blue mixed fluorescence conversion layer can be formed by mixing red phosphor and blue phosphor in the encapsulating adhesive, and correspondingly, the green fluorescence conversion layer can be formed by mixing green phosphor in the encapsulating adhesive.
[0032] In this embodiment, the near-ultraviolet (NIUV) light chip can emit light from five sides, meaning that all four emitting sides and one emitting front of the NIUV chip can emit light. In this embodiment, the NIUV chip 121 and the composite phosphor conversion layer 122 can be fabricated into a high color gamut white light-emitting package using CSP (Chemical Photolithography) technology. In the light-emitting package, the light emitted by the NIUV chip 121 illuminates the composite phosphor conversion layer, is converted by the composite phosphor conversion layer, and then mixed with the NIUV light to form white light. The direct-packaged light-emitting package offers high cost-effectiveness.
[0033] The technical solution in this embodiment uses a near-ultraviolet light chip as the light-emitting chip to excite white light, and employs a composite fluorescent conversion layer including two layers to convert and mix the near-ultraviolet light. This avoids the disadvantages of blue light chips, such as relatively weak light emission in the red spectrum region, luminous color affected by the working current, high color difference, low color rendering index, and poor stability. As a result, a backlight source that is not easily affected by the current, has small color difference, high color rendering index, and low cost is obtained.
[0034] like Figure 2 As shown, another CSP backlight provided in this embodiment includes: a substrate 210, including a light-emitting circuit; a light-emitting package disposed on the substrate and electrically connected to the light-emitting circuit, including a near-ultraviolet light chip 221 and a composite fluorescence conversion layer 222 stacked from bottom to top, the composite fluorescence conversion layer 222 including a blue fluorescence conversion layer 2221, a green fluorescence conversion layer 2222 and a red fluorescence conversion layer 2223 stacked from bottom to top, the composite fluorescence conversion layer at least covers the top of the near-ultraviolet light chip, and is used to convert and mix the light emitted by the near-ultraviolet light chip to emit white light, the light-emitting package is fabricated by CSP technology; and a lens layer 230, the lens layer covering the light-emitting package without gaps.
[0035] In this embodiment, the near-ultraviolet (NIUV) chip can emit light from five sides, meaning that all four emitting sides and one emitting front of the NIUV chip can emit light. In this embodiment, the NIUV chip 221 and the composite phosphor conversion layer 222 can be fabricated into a high color gamut white light-emitting package using CSP technology. In the light-emitting package, the light emitted by the NIUV chip 221 illuminates the composite phosphor conversion layer, and through the blue phosphor conversion layer, green phosphor conversion layer, and red phosphor conversion layer, it can be converted into blue light, green light, and red light, respectively. After mixing with the NIUV light, white light is formed, thereby causing the light-emitting package to emit white light.
[0036] The technical solution in this embodiment uses a near-ultraviolet light chip as the light-emitting chip to excite white light, and employs a three-layer composite fluorescent conversion layer to convert and mix the near-ultraviolet light. This avoids the disadvantages of blue light chips, such as relatively weak light emission in the red spectrum region, chromaticity affected by the working current, high color difference, low color rendering index, and poor stability. As a result, a backlight source that is not easily affected by the current, has a small color difference, a high color rendering index, and low cost is obtained.
[0037] like Figure 3 As shown, another CSP backlight provided in this embodiment includes: a substrate 310, including a light-emitting circuit; a light-emitting package disposed on the substrate and electrically connected to the light-emitting circuit, including a near-ultraviolet light chip 321 and a composite fluorescence conversion layer 322 stacked from bottom to top, the composite fluorescence conversion layer 322 including a blue fluorescence conversion layer 3221, a green fluorescence conversion layer 3222 and a red fluorescence conversion layer 3223 stacked from bottom to top, the composite fluorescence conversion layer at least covering the top of the near-ultraviolet light chip, used to convert and mix the light emitted by the near-ultraviolet light chip to emit white light, the light-emitting package is fabricated by CSP technology; and a lens layer 330, the lens layer covering the light-emitting package without gaps.
[0038] In this embodiment, the near-ultraviolet (NIUV) chip can be unilaterally emitting, meaning that only one emitting side of the NIUV chip emits light. In this embodiment, the NIUV chip 321 and the composite phosphor conversion layer 322 can be fabricated into a high color gamut white light-emitting package using CSP technology. In the light-emitting package, the light emitted by the NIUV chip 321 illuminates the composite phosphor conversion layer, and through the blue phosphor conversion layer, green phosphor conversion layer, and red phosphor conversion layer, it can be converted into blue light, green light, and red light, respectively. After mixing with the NIUV light, white light is formed, thus enabling the light-emitting package to emit white light.
[0039] The technical solution in this embodiment uses a near-ultraviolet light chip as the light-emitting chip to excite white light, and employs a three-layer composite fluorescent conversion layer to convert and mix the near-ultraviolet light. This avoids the disadvantages of blue light chips, such as relatively weak light emission in the red spectrum region, chromaticity affected by the working current, high color difference, low color rendering index, and poor stability. As a result, a backlight source that is not easily affected by the current, has a small color difference, a high color rendering index, and low cost is obtained.
[0040] In this embodiment, the near-ultraviolet (NIUV) light chip can be a MiniLED NIUV chip. MiniLED refers to an LED chip with a size on the order of 100 μm. The light-emitting package emits white light, and since the light-emitting chip is a MiniLED, a high color gamut white light MiniCOB package is formed. Preferably, the NIUV chip is generally circular or square, and its excitation wavelength is between 355 nm and 405 nm.
[0041] In the embodiments of this disclosure, the composite fluorescence conversion layer can be a nitride phosphor layer, a fluoride phosphor layer, and a silicate phosphor layer composed of nitride phosphor, fluoride phosphor, and silicate phosphor. Since the composite fluorescence conversion layer is a stacked blue fluorescence conversion layer, a red fluorescence conversion layer, and a green fluorescence conversion layer, blue phosphor can be mixed into the encapsulating adhesive to form a blue fluorescence conversion layer, red phosphor can be mixed into the encapsulating adhesive to form a red fluorescence conversion layer, and green phosphor can be mixed into the encapsulating adhesive to form a green fluorescence conversion layer.
[0042] The red and green phosphors can be narrow-peak phosphors such as green β-sialon, and the red phosphor can be narrow-peak red phosphors such as KSF or QD, but are not limited to these. When the near-ultraviolet light emitted by the near-ultraviolet chip is irradiated onto the composite phosphor conversion layer, it can be converted into blue, red, and green light, which are then mixed with the near-ultraviolet light to form white light, thereby causing the light-emitting package to emit white light.
[0043] In this embodiment, the lens layer includes a diffusion layer, a reflective layer, and a lens arranged sequentially from bottom to top. The front surface of the lens layer is arc-shaped, and the light-emitting package is located in the middle of the arc-shaped lens layer. With the center of the light-emitting package as the optical center, covering the entire light-emitting package with the lens layer opens up the beam angle of the light-emitting package. The lens layer and the light-emitting package are integrated into one unit without gaps or cavities, forming an optical lens structure with a large emission angle. Opening up the emission angle of the light-emitting package allows for a larger coverage area, thereby reducing the number of Mini LEDs used within the same specifications.
[0044] Specifically, a diffusion layer, a reflective layer, and a lens are arranged sequentially from bottom to top: the diffusion layer is placed on the front side of the light-emitting package, the reflective layer is placed on the front side of the diffusion layer, and the lens is placed on the front side of the reflective layer.
[0045] In this embodiment, the diffusion layer can be a white adhesive layer or a silicone layer containing diffusion powder; the reflective layer can be a white adhesive layer or a silicone layer containing diffusion powder. The diffusion powder can be silicon dioxide, titanium dioxide, or solid particles of a mixture of silicon dioxide and titanium dioxide. The diffusion powder in this embodiment enhances the light diffusion of the lens, allowing the light emitted from the light source to be distributed more evenly, reducing glare and shadows. Furthermore, the diffusion powder can maintain high light transmittance while ensuring light diffusion, reducing light energy loss.
[0046] In this embodiment, the interface between the light-emitting package and the diffusion layer is a plane, while the interface between the diffusion layer and the reflective layer, as well as the interface between the reflective layer and the lens, are curved surfaces, with the curved surfaces protruding in a direction away from the near-ultraviolet light chip.
[0047] Specifically, when the front surface of the light-emitting package is flat, the interface between the light-emitting package and the diffusion layer is flat, and the rear surface of the diffusion layer is flat, the diffusion layer can cover the light-emitting package without gaps, ensuring that each light-emitting package has a sufficient emission angle. Similarly, when the front and rear surfaces of the lens are curved, and the interfaces between the reflective layer and the lens, and between the diffusion layer and the reflective layer, are also curved, the diffusion layer, reflective layer, and lens of the lens layer can sequentially cover the light-emitting package without gaps, ensuring that each light-emitting package has a sufficient emission angle.
[0048] like Figure 4 As shown, the CSP backlight in this embodiment further includes an optical film assembly, which is disposed in the light emission direction of the light-emitting package. The optical film assembly includes a composite optical film 410 and a diffuser plate 420. The diffuser plate 420 is disposed in the light emission direction of the lens layer, and the composite optical film 410 is located in front of the diffuser plate 420. The optical film assembly can change the direction of light propagation and reflection; it can be single-layered or multi-layered and composed of different types of materials. Different effects can be achieved by changing different parameters such as materials, thickness, reflectivity, and transmittance.
[0049] Composite optical films are multifunctional optical film materials that assemble multiple different optical films into a single sheet using a composite process. While maintaining their optical performance, composite optical films can achieve overall thinning and cost reduction in display devices, and improve the yield and efficiency of backlight module assembly. A diffuser plate is a component used in optical systems, its main function being to diffuse or uniformly distribute light. Through surface frosting, dotting, prism, and other processing techniques, diffuser plates can uniformly diffuse light, reducing glare and bright spots, and improving the uniformity and softness of light. In backlight modules and other fields, diffuser plates are used to uniformly diffuse the light emitted by the backlight across the entire screen to improve light uniformity and softness. Diffuser plates are typically made of materials with high light transmittance and good diffusion properties, such as PS (polystyrene), PC (polycarbonate), and acrylic.
[0050] Based on the above CSP backlight, this disclosure embodiment can also provide a display device, which includes a display panel and the CSP backlight in the above technical solution.
[0051] According to the CSP backlight provided in this disclosure, by using a near-ultraviolet light chip as the backlight's light-emitting chip, the problem of relatively weak light emission in the red spectrum region of the blue light chip and the influence of the operating current on the luminous color of the light source can be avoided, thereby improving the color stability and color rendering performance of the backlight.
[0052] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.
Claims
1. A CSP backlight, characterized in that, The CSP backlight includes: Substrate, including light-emitting circuitry; A light-emitting package, disposed on the substrate and electrically connected to the light-emitting circuit, includes a near-ultraviolet light chip and a composite fluorescence conversion layer stacked sequentially from bottom to top. The composite fluorescence conversion layer includes at least two fluorescence conversion layers and covers at least above the near-ultraviolet light chip. It is used to convert and mix the light emitted by the near-ultraviolet light chip to emit white light. The light-emitting package is fabricated using chip-scale packaging (CSP) technology. A lens layer that covers the light-emitting package without gaps.
2. The CSP backlight according to claim 1, characterized in that, The near-ultraviolet light chip is a MiniLED near-ultraviolet light chip.
3. The CSP backlight according to claim 1, characterized in that, The composite fluorescence conversion layer includes a blue fluorescence conversion layer, a green fluorescence conversion layer, and a red fluorescence conversion layer stacked sequentially from bottom to top.
4. The CSP backlight according to claim 1, characterized in that, The lens layer includes a diffusion layer, a reflection layer, and a lens arranged sequentially from bottom to top.
5. The CSP backlight according to claim 4, characterized in that, The diffusion layer is a white glue layer or a silicone layer containing diffusion powder; and / or, the reflective layer is a white glue layer or a silicone layer containing diffusion powder.
6. The CSP backlight according to claim 1, characterized in that, The CSP backlight also includes an optical film assembly, which is disposed in the light emission direction of the light-emitting package.
7. The CSP backlight according to claim 4, characterized in that, The interface between the light-emitting package and the diffusion layer is planar, while the interface between the diffusion layer and the reflective layer, as well as the interface between the reflective layer and the lens, are curved surfaces, with the curved surfaces protruding away from the near-ultraviolet chip.
8. The CSP backlight according to claim 6, characterized in that, The excitation wavelength of the near-ultraviolet light chip is 355nm to 405nm.
9. A display device, characterized in that, It includes a display panel and a CSP backlight as described in any one of claims 1 to 8.