LED lamp plate

Abstract

The present invention is applied to the field of LED technology, and provides an LED lamp plate, which includes a substrate provided with a circuit layer. The circuit layer has pads for connecting a plurality of LED chips. A first light reflection layer is provided on the circuit layer, and a plurality of window opening structures are provided on the first light reflection layer. Each window opening structure is arranged, and at least a pair of pads for connecting with the LED chips are distributed in each window opening structure. The LED lamp plate further includes a second light reflection layer filled between the first light reflection layer and the LED chips, and the reflectivity of the second light reflection layer is greater than that of the first light reflection layer. The LED lamp plate according to the present invention is easy to die bond, has high luminous efficiency of the LED lamp plate, improves the process yield, and has low manufacturing cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of LED packages, and particularly relates to an LED lamp plate.

Background Art

[0002] In recent years, LED backlight lamp plates can achieve local dimming and have significantly improved display image quality. Therefore, they are favored in the market, and their popularization in the market is being vigorously promoted. Mini-LED backlight display modules and direct display products have become the mainstream of the future display market. In the prior art, for an LED backlight lamp plate using a glass substrate, a layer of white ink is applied to the glass substrate, and a window opening process needs to be performed at the location where the LED chip is placed to expose the pads. Therefore, the window opening process of the white ink, which is convenient for welding the LED chip and the pads (i.e., die bonding), has a great impact on the light-emitting efficiency of the backlight lamp plate. If the window opening is too large (exposing the glass substrate), the light emitted by the LED will be transmitted through the glass and lost. If the window opening is too small, the ink will cover the pads and cause die bonding defects. At the same time, the reflectivity of the white ink is generally not high, and the light-emitting efficiency of the LED backlight lamp plate is always limited by the reflectivity of the white ink. Therefore, the light-emitting efficiency of the LED backlight lamp plate is relatively low, which is disadvantageous for improving the backlight brightness.

[0003] On the one hand, the flip-chip process structure used for the lamp plate of the mini-LED backlight display module in the prior art conforms to the needs of ultra-small space density and is compatible with package substrates of various materials. The material of the substrate for the package of the mini-LED backlight display module is generally a PCB (Printed Circuit Board) substrate or a glass substrate. The package adhesive layer on the surface of the mini-LED backlight display module generally selects a silicone resin or an epoxy resin material. The thermal expansion coefficient of the PCB substrate or the glass substrate is (1-15)×10-6 / °C, and the thermal expansion coefficient of the silicone resin or the epoxy resin is about (50~220)×10-6 / °C. Since there is a large thermal expansion mismatch between the substrate and the package adhesive layer, there are risks such as warping, delamination, deformation, poor airtightness, and chip peeling of the substrate. The substrate and the package adhesive are separated out of sync due to the large difference in thermal expansion coefficient (the thermal expansion coefficient of the package adhesive is much larger than that of the substrate) during cooling or heating (for example, when performing a thermal shock test). In the prior art, by reducing the difference in thermal expansion coefficient between the substrate and the adjacent package adhesive, the deformation is reduced, but the stress existing in the substrate is not removed, the substrate is prone to deformation, the difficulty of reducing the difference in thermal expansion coefficient between the substrate and the adjacent package adhesive is high, and the production cost is high.

[0004] In addition, the shapes of LED products are diverse. Even for products of the same type, their applications in terminals vary greatly. For display products, high contrast is required; for white light products, high brightness is required; for single-color light, color purity is required, etc. Thus, clients' requirements for lamp beads also vary. The BT (Bismaleimide Triazine) plates commonly used in LED packages come in only two types, black and white. At the same time, the circuit design inside the PCB needs to meet the recipe requirements in the packaging process, and it is necessary to leave a metal functional area for the bonding operation in the LED packaging process.The primary colors of the metal functional area and the BT plate both affect the base color of the LED chip after packaging. For example, in display products, using a black paste package to improve contrast significantly reduces the product's brightness and cannot completely cover the bottom functional area. For certain white light products, relatively high brightness is required, but the choice of larger-sized chips is restricted by the bead size. In this case, improving brightness has to rely on the chip manufacturer to improve the luminous efficiency of the LED chip, but the improvement amount is extremely small and very limited, and the cost is high. And the normal packaging process of the mini COB (chip on board) backlight lamp plate is to die-bond the LED flip chip onto the circuit layer of the substrate, and then cover and protect the LED chip and the circuit layer with a layer of transparent protective gel. The LED chip generally emits light in a Lambertian pattern, that is, the light emission from the center of the LED chip is strong, and the light emission on both sides is weak. In order to obtain a larger emission angle and more uniform light emission, in the prior art, generally, a layer of light reflection layer is covered directly above the LED chip to reflect the light emitted from the surface of the LED chip to both sides. However, in such a form, although a large emission angle can be obtained, the light reflection layer does not transmit light, and the light from the LED chip is reflected multiple times between the light reflection layer and the substrate. Since the reflectivity of the substrate does not reach 100%, in multiple reflections, the substrate absorbs some light, resulting in large light loss, significantly reducing the luminous efficiency and brightness of the backlight lamp plate. At the same time, due to the low brightness directly above the LED chip, the uniformity of the backlight lamp plate is not good.

[0005] Based on the above technical problems in the LED lamp plate and its manufacturing, developers need to make improvements.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The object of the present invention is to provide an LED lamp plate that is easy to die bond, has high luminous efficiency, improves the process yield, and has low manufacturing cost, at least to eliminate the drawbacks of the above prior art.

Means for Solving the Problems

[0007] The present invention is an LED lamp plate including a substrate and an LED chip, wherein a circuit composite layer having pads for connecting to the LED chip is provided on the substrate.

[0008] As a further improvement of the present invention, a first light reflection layer is provided on the circuit composite layer, a plurality of window opening structures are provided on the first light reflection layer, at least a pair of the pads are provided in a region corresponding to each of the window opening structures, the LED chip is provided in the window opening structure and connected to the pads in the corresponding window opening structure, an accommodation region is formed between the outer peripheral side of the LED chip and the inner peripheral side of the window opening structure, and the LED lamp plate further includes a second light reflection layer filled in the accommodation region.

[0009] As a further improvement of the present invention, the circuit composite layer includes a circuit layer and a solder resist layer provided on the circuit layer and having a window opening structure, at least a pair of the pads are provided in a region corresponding to each of the window opening structures, the LED chip is provided in the window opening structure and connected to the pads in the corresponding window opening structure, the LED lamp plate further includes a first package adhesive layer provided on one side of the substrate and covering the LED chip and the circuit composite layer, the first package adhesive layer permits transmission of light emitted by the LED chip, and the LED lamp plate further includes a second package adhesive layer provided on the other side of the substrate for partially or completely offsetting the stress on the substrate by the first package adhesive layer.

[0010] As a further improvement of the present invention, the circuit composite layer includes a circuit layer and a solder resist layer provided on the circuit layer and having a windowed structure. At least a pair of the pads are provided in a region corresponding to each of the windowed structures. The LED chip is provided in the windowed structure and connected to the pads in the corresponding windowed structure. The LED chip is located in the windowed structure and connected to the circuit layer. The LED lamp plate further includes a colored adhesive layer. The colored adhesive layer is filled in the windowed structure. The colored adhesive layer is connected to the LED chip and the solder resist layer respectively. The color of the colored adhesive layer is the same as the color of the solder resist layer.

[0011] As a further improvement of the present invention, the second light reflection layer is made of resin, and light reflection particles are dispersed in the second light reflection layer.

[0012] As a further improvement of the present invention, the second light reflection layer is formed by dispensing in the windowed structure.

[0013] As a further improvement of the present invention, the LED chip is a flip chip, and there is a gap between the surface of the LED chip facing the substrate and the substrate. The second light reflection layer includes a side surface light reflection portion in contact with the outer peripheral side of the LED chip and a bottom surface light reflection portion filled in the gap.

[0014] As a further improvement of the present invention, a solder paste layer for connecting to the LED chip is provided on the surface of the pad, and the second light reflection layer covers the periphery of the connection location between the LED chip and the solder paste layer.

[0015] As a further improvement of the present invention, the top surface of the first light reflection layer is located between the bottom surface and the top surface of the LED chip, and the top surface of the second light reflection layer is not higher than the top surface of the first light reflection layer.

[0016] As a further improvement of the present invention, the reflectivity of the second light reflection layer is greater than that of the first light reflection layer.

[0017] As a further improvement of the present invention, the first light reflection layer is made of white ink.

[0018] As a further improvement of the present invention, the thickness range of the first light reflection layer is 20 μm to 80 μm.

[0019] As a further improvement of the present invention, the size of the window opening structure satisfies the relationship of Bx < Px and By < Py, where Bx represents the maximum size in the horizontal direction of the window opening structure, By represents the maximum size in the vertical direction of the window opening structure, Px represents the horizontal pitch between two adjacent LED chips, and Py represents the vertical pitch between two adjacent LED chips.

[0020] As a further improvement of the present invention, the window opening structure is a rectangular through-hole, and the longitudinal size of the rectangular through-hole is 2 mm or more.

[0021] As a further improvement of the present invention, a plurality of LED chips are provided, the LED lamp plate further includes a plurality of reflection patterns, the second light reflection layer is coated above the substrate and the LED chips, the reflection patterns are provided on the upper surface of the second light reflection layer, the reflection patterns include a plurality of reflection means provided at intervals, an air gap is formed between the reflection means, the reflection means includes a resin and reflection particles dispersed in the resin, the reflection particle density in the central region of the reflection pattern is greater than that in the outer peripheral region of the reflection pattern, the first light reflection layer is provided on the surface of the circuit composite layer to which the LED chips are connected, and one surface of the second light reflection layer is coated with the first light reflection layer and the LED chips.

[0022] As a further improvement of the present invention, in one of the reflection patterns, the area of the air gap occupies 20% to 80% of the area of the contour of the reflection pattern, and / or the thickness of the reflection pattern is 10 μm to 60 μm.

[0023] As a further improvement of the present invention, the reflection means includes a reflection ring located in the central region of the reflection pattern.

[0024] As a further improvement of the present invention, the reflection means includes a plurality of the reflection rings provided at the same center, and there is a gap between adjacent reflection rings.

[0025] As a further improvement of the present invention, reflection points are provided on the outer periphery of the reflection ring, and the distribution density of each reflection point decreases as it moves away from the center of the reflection pattern.

[0026] As a further improvement of the present invention, the reflection means includes a plurality of reflection points surrounding the center of the reflection pattern, and the area of the reflection points decreases as it moves away from the center of the reflection pattern.

[0027] As a further improvement of the present invention, the reflectivity of the reflection means in the central region of the reflection pattern is greater than the reflectivity of the reflection means in the outer peripheral region of the reflection pattern.

[0028] As a further improvement of the present invention, the reflection means in the central region of the reflection pattern contains titanium dioxide particles, and the reflection means in the outer peripheral region of the reflection pattern contains silica particles.

[0029] As a further improvement of the present invention, the reflection pattern is formed by screen printing, and a release slope is provided on the side wall of the reflection means.

[0030] As a further improvement of the present invention, it further includes an optical film provided above the second light reflection layer, a diffusion pattern is printed on the surface of the optical film, and the diffusion pattern of the optical film and the reflection pattern are arranged alternately.

[0031] As a further improvement of the present invention, the thickness of the first package adhesive layer is greater than that of the second package adhesive layer. The first package adhesive layer has a first coefficient of thermal expansion, and the second package adhesive layer has a second coefficient of thermal expansion that is greater than the first coefficient of thermal expansion.

[0032] As a further improvement of the present invention, the materials of the first package adhesive layer and the second package adhesive layer are the same, and both are epoxy resin or silicone resin.

[0033] As a further improvement of the present invention, inorganic light-transmitting particles for adjusting its coefficient of thermal expansion are dispersedly provided in the first package adhesive layer.

[0034] As a further improvement of the present invention, when the inorganic light-transmitting particles settle in the first package adhesive layer, the content of the inorganic light-transmitting particles gradually decreases along the direction away from the substrate.

[0035] As a further improvement of the present invention, the particle size range of the inorganic light-transmitting particles is 50 nm to 5 μm.

[0036] As a further improvement of the present invention, the inorganic light-transmitting particles are at least one of silica powder or alumina powder.

[0037] As a further improvement of the present invention, the thickness range of the first package adhesive layer is 150 μm to 400 μm, and / or the thickness range of the second package adhesive layer is 20 μm to 200 μm.

[0038] As a further improvement of the present invention, the first package adhesive layer is in direct contact with the substrate through the window opening structure.

[0039] As a further improvement of the present invention, the upper ends of both the colored adhesive layer and the solder resist layer are lower than the upper end of the LED chip.

[0040] As a further improvement of the present invention, the thickness range of the solder resist layer is 20 μm to 50 μm.

[0041] As a further improvement of the present invention, the LED lamp plate is provided on the top of the solder resist layer and the top of the colored adhesive layer, and further includes a package adhesive layer covering the LED chip.

[0042] As a further improvement of the present invention, the materials of the colored adhesive layer and the package adhesive layer are the same, and both are epoxy resin or silica gel.

[0043] As a further improvement of the present invention, the colors of the colored adhesive layer and the solder resist layer are white or black.

[0044] As a further improvement of the present invention, the colored adhesive layer is made of a colored ink or a colored colloid with a viscosity of less than 2000 mPa·s.

[0045] As a further improvement of the present invention, the inner wall of the window opening structure or the circuit layer has a rounded or chamfered structure.

[0046] As a further improvement of the present invention, there are a plurality of the window opening structures, and one or more of the LED chips are face-up or flip-chip and are fixed in each of the window opening structures.

[0047] The LED lamp plate according to the present invention includes a substrate provided with a circuit layer, the circuit layer has pads for connecting a plurality of LED chips, a first light reflection layer is provided on the circuit layer, a plurality of window opening structures are provided on the first light reflection layer, each of the window opening structures is arranged, and at least a pair of pads for connecting to the LED chips are distributed in each of the window opening structures. The LED lamp plate further includes a second light reflection layer filled between the first light reflection layer and the LED chips, and the reflectivity of the second light reflection layer is greater than that of the first light reflection layer. The LED lamp plate according to the present invention is easy to die-bond, has high luminous efficiency, improves the process yield, and has low manufacturing cost. Alternatively, the first package adhesive layer is provided on one side of the substrate, covers the LED chip and the circuit layer, the first package adhesive layer permits the transmission of light emitted by the LED chip, the second package adhesive layer is provided on the other side of the substrate, and is used to partially or completely offset the stress on the substrate caused by the first package adhesive layer, thereby effectively reducing the warping deformation caused by the stress of the substrate, effectively improving problems such as delamination, deformation, and poor airtightness after the lamp plate is sealed, avoiding the risk of defects such as peeling of the LED chip, and having low production cost. Alternatively, the LED chip is exposed from the substrate, and colored adhesive layers of the same color as the solder resist layer are connected to the LED chip and the solder resist layer respectively. The colored adhesive layer can completely cover the remaining area of the substrate, that is, the colored adhesive layer is filled in the window opening structure and can also cover the outer peripheral area of the LED chip, effectively improving the color consistency of the substrate surface after encapsulation. Different colored colloids can be applied according to different situations to improve the emission luminance or the contrast. For example, when the LED package structure is used in a white light LED product, using a white adhesive layer can strengthen the light reflection effect in the outer peripheral area of the LED chip and effectively improve the luminance of the white light. For example, when the LED package structure is used in an RGB-LED direct display product, using a black adhesive layer can reduce the light reflection in the outer peripheral area of the RGB-LED chip, reduce the light reflection effect, and effectively improve the contrast. When used in a single-color light LED product, using a colored adhesive layer of the corresponding color system can prevent the light emitted by the LED chip from being mixed with light of other colors and ensure the light emission purity.

[0048] In the following, to more clearly explain the configuration in the embodiments of the present invention, the drawings necessary for use in the description of the embodiments will be briefly described. The drawings in the following description are only some embodiments of the present invention, and it is obvious that those skilled in the art can obtain other drawings based on these drawings without creative labor.

Brief Description of the Drawings

[0049]

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Mode for Carrying Out the Invention

[0050] Hereinafter, in order to make the object, configuration and advantages of the present invention clearer, the present invention will be described in more detail with reference to the drawings and embodiments. It should be noted that the specific embodiments described here are only for interpreting the present invention and do not limit the present invention.

[0051] It should be noted that the terms "installation" and "connection" should be understood in a broad sense. For example, they may be directly installed and connected, or may be indirectly installed and connected through intermediate parts and intermediate structures.

[0052] In addition, in the embodiments of the present invention, terms indicating orientation and positional relationships such as "vertical direction", "horizontal direction", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation and positional relationships shown in the drawings, the normal arrangement state and the usage state, and are merely for the convenience of explaining the present invention and for simplifying the explanation, and do not indicate or imply that the shown structure, feature, device or element has a specific orientation or positional relationship, nor is it necessary to configure and operate in a specific orientation, so it cannot be understood as limiting the present invention. Unless otherwise specified in this specification, the meaning of "a plurality" is two or more.

[0053] Each specific configuration and each embodiment described in the embodiments for carrying out the present invention can be combined in any appropriate manner as long as there is no contradiction. For example, different specific configurations / embodiments may be combined to form different embodiments. For the sake of avoiding redundancy, various possible combination forms of each specific configuration / embodiment in the present invention will not be described separately.

[0054] The LED lamp plate according to the embodiment of the present invention includes a substrate and an LED chip. A circuit composite layer is provided on the substrate. The circuit composite layer has pads for connecting to the LED chip. A first light reflection layer is provided on the circuit composite layer. A plurality of window opening structures are provided on the first light reflection layer. At least a pair of the pads are provided in a region corresponding to each of the window opening structures. The LED chip is provided in the window opening structure and is connected to the pads in the corresponding window opening structure. A receiving region is formed between the outer peripheral side of the LED chip and the inner peripheral side of the window opening structure. The LED lamp plate further includes a second light reflection layer filled in the receiving region, or The circuit composite layer includes a circuit layer and a solder resist layer provided on the circuit layer and having a windowed structure, and has at least a pair of the pads in a region corresponding to each of the windowed structures. The LED chip is provided in the windowed structure and connected to the pad in the corresponding windowed structure. The LED lamp plate further includes a first package adhesive layer. The first package adhesive layer is provided on one side of the substrate, covers the LED chip and the circuit composite layer, and the first package adhesive layer permits transmission of light emitted by the LED chip. The LED lamp plate is provided on the other side of the substrate and further includes a second package adhesive layer for offsetting part or all of the stress on the substrate caused by the first package adhesive layer. Or, The circuit composite layer includes a circuit layer and a solder resist layer provided on the circuit layer and having a windowed structure, and has at least a pair of the pads in a region corresponding to each of the windowed structures. The LED chip is provided in the windowed structure and connected to the pad in the corresponding windowed structure. The LED chip is located in the windowed structure and connected to the circuit layer. The LED lamp plate further includes a colored adhesive layer. The colored adhesive layer is filled in the windowed structure and is connected to the LED chip and the solder resist layer respectively. The color of the colored adhesive layer is the same as that of the solder resist layer, which is easy to die bond, has high luminous efficiency, high manufacturing efficiency, and low manufacturing cost. Hereinafter, the present invention will be further described with reference to specific embodiments.

[0055] Embodiment 1 The LED lamp plate according to an embodiment of the present invention, as shown in FIGS. 1 to 9, includes a substrate and an LED chip 1. In this embodiment, the substrate is a glass substrate 6 (shown in FIG. 1), and a circuit composite layer 3 is provided on the substrate. In this embodiment, the circuit composite layer includes a circuit layer 3, that is, the circuit layer 3 is provided on the surface of the glass substrate 6. A plurality of the LED chips 1 are provided. The circuit layer 3 has at least a pair of pads for connecting to the plurality of LED chips 1 (shown in FIG. 2). A first light reflection layer 4 is provided on the circuit layer 3 (shown in FIG. 3). The lower surface of the first light reflection layer 4 is covered by the circuit layer 3. A plurality of window opening structures 41 are provided on the first light reflection layer 4 (shown in FIG. 4). The window opening structure 41 is a hole position penetrating the first light reflection layer 4. The LED chip 1 is provided in the window opening structure 41 (shown in FIG. 5) and is connected to the pads in the corresponding window opening structure 41. Each of the window opening structures 41 in this embodiment is arranged. The window opening area of the window opening structure 41 is larger than the projected area of the LED chip 1 on the glass substrate 6, exposing the locations on the surface of the glass substrate 6 where the LED chip 1 needs to be welded, and facilitating the placement of the LED chip 1 in the window opening structure 41, that is, the window opening structure 41 is provided such that the pads are exposed. Further, it avoids the pads being covered by the first light reflection layer 4, facilitating the welding of the LED chip 1 located in the window opening structure 41 and the corresponding pads. If the gap between the window opening structure 41 and the LED chip 1 is too small, it becomes difficult to install. If the gap is too large, light leakage is likely to occur, affecting the luminous efficiency and the process yield. The size of the window opening structure 41 is larger than the outer size of the LED chip 1, and an accommodation region 410 is formed between the outer peripheral side of the LED chip 1 and the inner peripheral side of the window opening structure 41. The LED lamp plate includes a second light reflection layer 5, and the second light reflection layer 5 is filled in the accommodation region 410 (shown in FIG. 5). That is, the second light reflection layer 5 is located within the window opening structure 41 and above the circuit layer 3 and on the outer peripheral side of the LED chip 1. The second light reflection layer 5 and the outer peripheral side of the LED chip 1 are in close contact, and the second light reflection layer 5 and the inner peripheral side of the window opening structure 41 are in close contact. The size of the window opening structure 41 is larger than the size of the LED chip 1 so that the LED chip 1 can be easily arranged within the window opening structure 41, with high manufacturing efficiency, low manufacturing cost, and it is easy to ensure a high die bonding yield. Moreover, the accommodation region 410 can be well filled by the second light reflection layer 5 filled therein to avoid light leakage gaps. The LED lamp plate according to the embodiment of the present invention is easy to perform die bonding, has high luminous efficiency, high manufacturing efficiency, and low manufacturing cost.

[0056] Furthermore, the reflectivity of the second light reflection layer 5 is larger than that of the first light reflection layer 4, and the reflectivity of the second light reflection layer 5 is higher than that of the first light reflection layer 4. More effective light rays are reflected by the second light reflection layer 5 having a high reflectivity, resulting in higher luminous efficiency, that is, the luminous efficiency is increased.

[0057] Furthermore, the top surface of the first light reflection layer 4 is located between the bottom surface and the top surface of the LED chip 1, and the top surface of the second light reflection layer 5 is not higher than the top surface of the first light reflection layer 4. The thickness range of the first light reflection layer 4 may be 20 μm to 80 μm. In a specific application, the second light reflection layer 5 is filled in the accommodation area 410 between the LED chip 1 and the first light reflection layer 4, that is, filled in the window opening structure 410. And the top surface of the second light reflection layer 5 may be lower than the top surface of the first light reflection layer 4, or may be flush with the top surface of the first light reflection layer 4. The second light reflection layer 5 in this embodiment is formed by coagulation of a colloid. The colloid has a certain fluidity, with good filling effect, avoiding defects such as glue shortage and light leakage gaps. The thickness of the first light reflection layer 4 is a (shown in FIG. 3), and the thickness of the second light reflection layer 5 is c (shown in FIG. 7). In order to prevent the colloid from overflowing onto the upper surface of the first light reflection layer 4, it is necessary to control the amount of adhesive for forming the second light reflection layer 5 so that the thickness c of the second light reflection layer 5 ≤ the thickness a of the first light reflection layer 4, avoiding the colloid of the second light reflection layer 5 from overflowing onto the first light reflection layer 4, which is convenient for ensuring the consistency of the light emission efficiency of the LED lamp plate. The range that a can take is 20μm to 80μm, and it is preferably 25μm to 60μm for a, and more preferably 50μm to 60μm for a.

[0058] Furthermore, the size of the window opening structure 41 satisfies the relationship of Bx < Px, By < Py, where Bx represents the maximum size in the horizontal direction of the window opening structure, By represents the maximum size in the vertical direction of the window opening structure, Px represents the horizontal pitch between two adjacent LED chips 1, and Py represents the vertical pitch between two adjacent LED chips 1. In a specific application, the window opening structure 41 is rectangular, and its maximum size is the length of the rectangle. As shown in FIG. 9, the window opening structure 41 may be a rectangular groove. The outer shape of the LED chip 1 is rectangular. The pitch value (Pitch) between the centers of two adjacent LED chips 1 is p (shown in FIGS. 8 and 9). The horizontal center pitch between two adjacent LED chips 1 is Px, and the vertical center pitch is Py. The maximum horizontal size of the window opening structure 41 is Bx, and the maximum vertical size is By (shown in FIGS. 8 and 9), and Bx < Px, By < Py. The accommodating area 410 may exhibit a "hui" character shape, and the length size of the rectangle is Bx ≥ 2 mm, preferably Bx ≥ 3 mm. In another embodiment, as shown in FIG. 8, the window opening structure 41 may be in the shape of a round hole. In this case, its maximum size is its diameter, and the diameter is smaller than both Px and Py. It is possible to ensure that the window opening area of the window opening structure 41 is larger than the projected area of the LED chip 1 on the glass substrate 6, which is advantageous for exposing the locations on the surface of the glass substrate 6 where the LED chip 1 needs to be welded. The LED chip 1 may be provided at the center of the window opening structure 41, and there is no communication between adjacent window opening structures 41, which is advantageous for production and cost reduction.

[0059] Furthermore, the LED chip 1 may be a flip chip, and there is a gap between the surface of the LED chip 1 facing the glass substrate 6 and the glass substrate 6. The second light reflection layer 5 includes a side surface light reflection portion 51 and a bottom surface light reflection portion 52. The side surface light reflection portion 51 is connected to the outer peripheral side of the LED chip 1 as shown in FIG. 7, and the bottom surface light reflection portion 52 is filled in the gap and connected to the bottom surface of the LED chip 1.

[0060] Furthermore, a solder paste layer 7 is provided on the surface of the pad. The metal solder paste of the solder paste layer 7 exhibits a gray color and absorbs blue light. The LED chip 1 is connected to the pad through the solder paste layer 7, forming a gap filled by the bottom surface light reflection portion 52 described above. The solder paste layer 7 is connected to the LED chip 1. Specifically, when solder paste is printed on the pad and the LED chip 1 is welded to the pad, die bonding is completed. The top surface of the first light reflection layer 4 is located between the bottom surface and the top surface of the LED chip 1. If the first light reflection layer 4 is higher than the top surface of the LED chip 1, it will cause light shielding. The first light reflection layer 4 is lower than the bottom surface of the LED chip 1 so that the solder paste layer 7 is exposed. In this embodiment, the LED chip 1 is connected to the pad via a solder paste layer 7 (metal solder paste). The metal solder paste presents a gray color. The bottom surface light reflection part 52 located at the bottom of the LED chip 1 is covered by the metal solder paste layer 7, which can avoid the absorption of blue light by the solder paste layer 7.

[0061] Furthermore, the first light reflection layer 4 may be made of white ink. The second light reflection layer 5 is made of silica gel or silicone resin, and light reflection particles are dispersedly provided in the second light reflection layer 5. In a specific application, the second light reflection layer 5 includes at least one of TiO2 light reflection particles and BaSO4 light reflection particles. Mixing a certain amount of light reflection particles into the adhesive is beneficial to further improve the reflectivity of the second light reflection layer 5. The light reflection layer of the LED lamp plate may adopt a combination of white ink and white adhesive. Both the white adhesive and white ink may be used as reflection materials. White ink has a low cost but a low reflectivity and poor fluidity, and is suitable for large-area printing. In contrast, the white adhesive is expensive, has a high reflectivity, and strong fluidity, and is generally used as a dispenser for local caps in the prior art. In this embodiment, the first light reflection layer 4 is made of white oil (white ink) with a low cost, while the second light reflection layer 5 is made of white adhesive with good fluidity and a good filling effect. The reflectivity of the first light reflection layer 4 is generally 93% or less, and the reflectivity of the second light reflection layer 5 is 98% or more, which simultaneously solves the problems of difficult die bonding, low luminous efficiency, and high cost. In the conventional method, easy die bonding, high luminous efficiency, and low cost are conflicting constraints, and at least one of them must be sacrificed, and it is impossible to achieve both high cost and easy die bonding and high luminous efficiency at the same time. In addition, the LED lamp plate according to the present invention is easy to die bond, improves the luminous efficiency at the same time, has high efficiency and low cost, so it is easy to die bond, ensures high luminous efficiency, balances the cost, has high operability in actual production, and has high market application value.

[0062] Referring to FIGS. 1 to 9, an embodiment of the present invention further provides a method for manufacturing an LED lamp plate for manufacturing the above-mentioned LED lamp plate, which includes the following steps.

[0063] As shown in FIG. 1, a substrate is manufactured. In this embodiment, a glass substrate 6 with good stability and low cost is used.

[0064] As shown in FIG. 2, a circuit layer 3 having pads is provided on the substrate. Specifically, a circuit layer 3 having pads and connected to a plurality of LED chips 1 is printed on the substrate.

[0065] As shown in FIG. 3, a first light reflection layer 4 made of a first light reflection material is provided on the circuit layer 3. Specifically, in this embodiment, it is printed on the circuit layer 3 with white ink to form the first light reflection layer 4.

[0066] As shown in FIG. 4, a plurality of window opening structures 41 are provided in the first light reflection layer 4, and at least a pair of the pads are provided in the region of each window opening structure 41. Specifically, in this embodiment, the window opening structure 41 is formed by an exposure etching process. A plurality of arranged window opening structures 41 are provided in the first light reflection layer 4. In this embodiment, the window opening structure 41 is a rectangular groove (shown in FIG. 7). In other embodiments, the window opening structure 4 may also be in the shape of a round hole (shown in FIG. 8).

[0067] As shown in FIG. 5, the LED chip 1 is provided in the window opening structure 41, and the LED chip 1 is connected to the pad. Specifically, the pad corresponding to the same LED chip 1 is also located within the window opening structure 41. That is, the LED chip 1 located within the window opening structure 41 is connected to the corresponding pad, and two or more LED chips 1 may be provided within each window opening structure 41.

[0068] As shown in FIG. 6, a second light reflecting material 50 (in this embodiment, the reflectivity of the second light reflecting material 50 is greater than that of the first light reflecting material) is filled within the window opening structure 41. As shown in FIG. 7, the second light reflecting material 50 is located between the first light reflecting layer 4 and the LED chip 1, forming a second light reflecting layer 5. Specifically, in this embodiment, the second light reflecting material 50 uses a white adhesive.

[0069] In the LED lamp plate and its manufacturing method according to the embodiment of the present invention, a first light reflecting layer 4 is provided on the circuit layer 3, a plurality of window opening structures 41 are provided on the first light reflecting layer 4, the LED chip 1 is provided within the window opening structure 41 and is connected to the pad within the corresponding window opening structure 41. An accommodation region 410 is formed between the outer peripheral side of the LED chip 1 and the inner peripheral side of the window opening structure 41. By filling the accommodation region 410 with a second light reflecting layer 5 having a high reflectivity, it is easy to perform die bonding, the manufacturing cost is low, and the reflectivity of the second light reflecting layer 5 is greater than that of the first light reflecting layer 4 so as to increase the luminous efficiency. The LED lamp plate and its manufacturing method according to the present invention are not only easy to perform die bonding, but also have high luminous efficiency, improve the yield of the manufacturing process, and have low manufacturing costs.

[0070] Example 2 As shown in FIG. 10, the LED lamp plate according to an embodiment of the present invention is a backlight lamp plate, and includes a substrate 100, a circuit layer 110, and a plurality of LED chips. The LED chips are light-emitting chips 210. One surface of the circuit layer 110 is provided on the substrate 100, and the light-emitting chips 210 are provided on the other surface of the circuit layer 110. The backlight lamp plate further includes a package adhesive layer 130 and a plurality of reflection patterns 300. The package adhesive layer 130 covers above the substrate 100 and the light-emitting chips 210. The reflection patterns 300 are provided on the upper surface of the package adhesive layer 130. The light-emitting surface of the light-emitting chips 210 faces the reflection patterns 300. The reflection patterns 300 include a plurality of reflection means 320 provided at intervals, and a gap 310 (which may be an air gap) is formed between the reflection means 320. The reflection means 320 includes a resin and reflection particles dispersed in the resin. The density of the reflection particles in the central region of the reflection patterns 300 is greater than that in the outer peripheral region of the reflection patterns 300. The reflection patterns 300 may reflect some of the light rays emitted from the light-emitting surface of the light-emitting chips 210. The backlight lamp plate further includes a first light reflection layer. In this embodiment, the first light reflection layer is a light reflection layer 120. The light reflection layer 120 (the first light reflection layer) is a white adhesive layer, and light reflection particles may be dispersedly embedded in the light reflection layer 120 (the first light reflection layer). The light reflection layer 120 (the first light reflection layer) is provided on the surface of the circuit layer 110 where the light-emitting chips 210 are connected. One surface (the back surface) of the package adhesive layer 130 covers the light reflection layer 120 (the first light reflection layer) and the light-emitting chips 210 (LED chips).

[0071] The reflecting means 320 is a reflection area (for reflecting light rays), the air gap 310 is an engraved area (for light rays to pass through), and part of the light rays emitted by the light-emitting chip 210 (LED chip) are directed towards the reflection area (901 in FIG. 10), while another part is directly emitted from the engraved area (902 in FIG. 10). The light rays directed towards the reflection area are reflected in the reflection area to form reflected light rays. After part of the reflected light rays are reflected by the light reflection layer, they are emitted from the engraved area and the side surface on the outer peripheral side of the light-emitting chip 210. In view of the characteristic that the light emission at the center of the LED chip is strong and the light emission on the outer peripheral side is weak, in this embodiment, an engraved structure is provided in the reflection pattern 300 to form an engraved area. By adjusting the area ratio and distribution of the engraved area so that the reflection particle density in the central area of the reflection pattern 300 is greater than that in the outer peripheral area, the intensity of the light emitted from the package adhesive layer 130 in the central area on the surface of the light-emitting chip 210 can be weakened, and the intensity of the light emitted from the package adhesive layer 130 in the side area of the light-emitting chip 210 can be increased. Part of the light emitted by the light-emitting chip 210 can pass directly through the engraved area and be emitted from the surface, and part is reflected in the reflection area, effectively adjusting the luminance above the light-emitting chip 210 (i.e., in the front, referring to the front in the light-emitting direction of the light-emitting chip 210), ensuring the light-emitting efficiency and luminance of the backlight lamp plate. At the same time, due to the local reflection effect of the reflection pattern 300, part of the light rays are reflected to the area on the side surface of the light-emitting chip 210, increasing the light-emitting angle after the light-emitting chip 210 passes through the package adhesive layer 130, increasing the light-emitting luminance on the outer peripheral side of the light-emitting chip 210, improving the light-emitting uniformity of the lamp plate, and having a good application effect.

[0072] Specifically, the light-emitting chip 210 is a flip mini LED chip and may be welded to the circuit layer 110 by the pads 220. Specifically, the light reflection layer 120 (the first light reflection layer) may be provided with a relief window (escape window) 121 at a location corresponding to the light-emitting chip 210, and the package adhesive layer 130 may be filled in the gap between the relief window 121 and the light-emitting chip 210. The reflection pattern 300 is provided on the other surface (the front surface) of the package adhesive layer 130, or the reflection pattern 300 is embedded inside the package adhesive layer 130. That is, the reflection pattern 300 may be sandwiched within the package adhesive layer 130 to form a sandwich structure, and the reflection pattern 300 may be covered by the package adhesive layer 130 to prevent unexpected damage. In this embodiment, the reflection pattern 300 may be formed on the other surface (the front surface) of the package adhesive layer 130 by screen printing. The process is simple and reliable, and the size and ratio of the embossed pattern can be controlled with high precision. The product has good integrity, high production efficiency, and low cost.

[0073] Specifically, in one of the reflection patterns 300, the area of the air gap 310 (the embossed area) occupies 20% - 80% of the area of the contour of the reflection pattern 300, which is advantageous for ensuring luminous efficiency and light emission uniformity. In a specific application, the area of the air gap 310 occupies 30% - 60% of the area of the contour of the reflection pattern 300, which improves the luminous efficiency and brightness of the backlight lamp plate and ensures the light emission uniformity of the backlight lamp plate.

[0074] In a specific application, the thickness of the reflection pattern 300 may be 10μm - 60μm, which has a good reflection effect and low application cost.

[0075] In a specific application, the reflection pattern 300 is made of a white adhesive. That is, the white adhesive may be screen printed onto the reflection pattern 300 having the embossed area, and the white adhesive may be a white silicone resin.

[0076] Alternatively, the reflection pattern 300 may include a white adhesive (white silicone resin) and light reflection particles embedded in the white adhesive. The light reflection particles may be titanium dioxide light reflection particles or / and silica light reflection particles in order to improve the reflection efficiency of light rays. In this embodiment, the reflectance corresponding to the reflection region of the reflection pattern 300 is ≧88%.

[0077] Specifically, the reflection means 320 may include a reflection region presenting a dot structure (shown in FIG. 10), a block structure, a linear structure, a grid structure or an annular structure. In a specific application, the reflection means 320 may present a dot shape, an annular shape (shown in FIG. 13), a polygon, a polygonal ring (hollow polygon), a straight line shape, a wavy line shape, a broken line shape, etc., and the reflection region may present a rectangular grid shape, a rhombic grid shape, etc.

[0078] In a specific application, as shown in FIG. 10, the density of the reflection region closer to the center of the light-emitting chip 210 (LED chip) is greater than the density of the reflection region away from the center of the light-emitting chip 210, that is, the reflection region may be arranged such that the center (referring to the center of the light-emitting chip 210) is relatively dense and the outer peripheral side is relatively sparse, which can effectively adjust the luminance above the light-emitting chip 210 and reinforce the luminance on the outer peripheral side of the light-emitting chip 210 (LED chip), and can improve the uniformity of the light-emitting efficiency.

[0079] Specifically, the embossed region may include an embossed region presenting a dot structure, a linear structure, a grid structure or an annular structure. In a specific application, the embossed region may present a dot shape, an annular shape, a polygon, a polygonal ring, a straight line shape, a wavy line shape, a broken line shape, etc., and the embossed region may present a rectangular grid shape, a rhombic grid shape, etc.

[0080] In a specific application, as shown in FIG. 11, the density of the embossed area near the center of the light-emitting chip 210 (LED chip) is smaller than the density of the embossed area away from the center of the light-emitting chip 210. That is, the air gap may be arranged such that the center (referring to the center of the light-emitting chip 210) is relatively dense and the outer peripheral side is relatively sparse, effectively adjusting the luminance above the light-emitting chip 210, reinforcing the luminance on the outer peripheral side of the light-emitting chip 210, and improving the uniformity of the luminous efficiency.

[0081] Of course, in some embodiments, the air gaps may be provided randomly or uniformly.

[0082] Specifically, one or at least two of the light-emitting chips 210 (LED chips) are provided. The reflection area includes a central reflection area and an outer peripheral reflection area. One central reflection area is provided directly above each of the light-emitting chips 210, and the outer peripheral reflection area is provided on the outer periphery of the central reflection area. The reflection area density of the central reflection area is greater than the reflection area density of the outer peripheral reflection area, which is advantageous for adjusting the luminance above the light-emitting chip 210, reinforcing the luminance on the outer peripheral side of the light-emitting chip 210, and improving the uniformity of the luminous efficiency.

[0083] As a preferred invention of the reflection area, as shown in FIG. 13, the reflection means 320 includes a plurality of reflection rings 321 provided at the same center, with a gap between adjacent reflection rings 321. The area corresponding to the gap is an air gap, and the reflection ring 321 may be an annular ring or a polygonal ring. The interval between the adjacent reflection rings 321 may be the same, or the size of the interval closer to the center of the reflection ring group may be smaller than the size of the interval farther from the center of the reflection ring group. The reflection ring 321 may be in an annular shape. In accordance with the light emission characteristic that the light emission from the center of the light emitting chip 210 (LED chip) is strong and the light emission from the edge is weak, the larger the radius of the reflection ring 321, the larger the interval between its outer side and the adjacent reflection ring 321. By making the light emitted after passing through the light reflection layer 120 (the first light reflection layer) more uniform, the luminance above the light emitting chip 210 can be adjusted, the luminance on the outer peripheral side of the light emitting chip 210 can be enhanced, and the uniformity of the light emission efficiency can be improved better.

[0084] Specifically, what is shown by the dashed line frame is the light emitting chip 210 (LED chip). Each of the light emitting chips 210 is provided with a corresponding reflection ring group along the immediate front of the light emission direction, and the center of the reflection ring group corresponds to the center of the light emitting chip 210, so that the luminance above the light emitting chip 210 can be adjusted well.

[0085] Specifically, a diffuse reflection structure may be provided on the outer periphery of the reflection ring. The diffuse reflection structure may be in the form of dots, strips, rings, etc., that is, the diffuse reflection structure may be a reflection point. In a specific application, each of the diffuse reflection structures is uniformly distributed, or the density of each of the diffuse reflection structures decreases as the distance from the center of the reflection pattern 300 increases, which is advantageous for enhancing the luminance on the outer peripheral side of the light emitting chip 210 (LED chip) and making the uniformity of the light emission efficiency better. In a specific application, the diffuse reflection structure may be a reflection point 322. The reflection points 322 may be distributed in a dot shape with an interval in the circumferential direction. The reflection points 322 may be circular or polygonal, etc., and are arranged at equal intervals along the circumferential direction of one or at least two concentric circles (concentric with the reflection ring 321). And the larger the radius of the concentric circle, the larger the interval of the reflection points 322 in the circumferential direction, that is, the larger the radius of the concentric circle, the fewer the number of reflection points 322 on the concentric circle (not shown). Based on the light intensity distribution curve (not shown) of the above backlight lamp plate, the reflection pattern 300 can effectively adjust the luminance above the chip, which is advantageous for improving the light emission uniformity of the backlight lamp plate.

[0086] As one of the preferred inventions, the air gap may include a plurality of embossed rings provided at the same center, and may include an embossed ring group having a gap between adjacent embossed rings. The embossed ring may be a circular ring or a polygonal ring. The gap between adjacent embossed rings may be equal, or the size of the gap closer to the center of the embossed ring group may be larger than the size of the gap farther from the center of the embossed ring group, so as to adjust the luminance above the light-emitting chip 210 (LED chip), reinforce the luminance on the outer peripheral side of the light-emitting chip 210, and make the uniformity of the light-emitting efficiency better.

[0087] As another preferred invention, the reflection region includes a strip-shaped reflection band and reflection points. The reflection points are located on the outer periphery of the reflection band, that is, in a region close to the center of the light-emitting chip 210 (LED chip). In the circumferential direction, the reflection band adopts a continuous strip-shaped distribution. In the outer peripheral region of the light-emitting chip 210, the reflection points may be distributed in a dot pattern with intervals in the circumferential direction. Each of the light-emitting chips 210 is provided with a corresponding reflection band along the immediate front of the light-emitting direction. The reflection bands are provided in multiple copies, and each reflection band is provided with an interval and / or intersects. By the reflection points presenting a circular shape or a polygonal shape, etc., the luminance above the light-emitting chip 210 can be adjusted, the luminance on the peripheral side of the light-emitting chip 210 can be reinforced, and the uniformity of the light-emitting efficiency can be made better.

[0088] In a specific application, it is advantageous that the reflection points are uniformly distributed, or the area of the reflection points becomes smaller as the distance from the center of the reflection pattern increases, which is beneficial for reinforcing the luminance on the outer peripheral side of the light-emitting chip 210, and the uniformity of the light-emitting efficiency can be made better.

[0089] In a specific application, the reflection means 320 includes a plurality of reflection points surrounding the center of the reflection pattern 300.

[0090] In a specific application, the package adhesive layer 130 may be a transparent adhesive layer so as to avoid light loss.

[0091] Specifically, the thickness of the package adhesive layer 130 may be 200 μm to 400 μm. The light has a certain reflection distance and space, which is beneficial to improving the luminous efficiency.

[0092] In a specific application, in order to facilitate the release of the screen and improve the product yield, as shown in FIG. 12, a release slope 131 may be selectively provided on the side wall of the reflection means 320.

[0093] In a specific application, as shown in FIG. 14, the reflection region includes a plurality of reflection blocks (which may be in a block shape). The area of the reflection block decreases along the direction away from the center of the light-emitting chip 210. The closer each reflection block is to the light-emitting chip 210, the relatively larger its unit area is. That is, the reflection block includes a central block 327 close to the light-emitting chip 210 and an outer peripheral block 328 located on the outer periphery of the central block 327. The size of the central block 327 is larger than that of the central block 327 so as to effectively adjust the luminance above the light-emitting chip 210, reinforce the luminance of the outer periphery of the light-emitting chip 210, and improve the uniformity of the luminous efficiency.

[0094] In a specific application, as shown in FIGS. 10, 11 and 14, the reflectivity of the reflection means 320 in the central region of the reflection pattern 300 is larger than the reflectivity of the reflection means 320 in the outer peripheral region of the reflection pattern 300. The reflection means 320 in the central region of the reflection pattern 300 includes titanium dioxide particles, and the reflection means 320 in the outer peripheral region of the reflection pattern 300 includes silica particles. Titanium dioxide particles may be provided in a portion of the reflection region close to the light-emitting chip 210, and silica particles may be provided in a portion of the reflection region away from the light-emitting chip 210.

[0095] In a specific application, as a preferred invention, the reflection block includes a central block 327 close to the light-emitting chip 210 and an outer peripheral block 328 located on the outer periphery of the central block 327. The reflectivity of the central block 327 is greater than that of the outer peripheral block 328. Titanium dioxide particles may be provided in the central block 327, and silica particles may be provided in the outer peripheral block 328. The size of the central block 327 may be equal to or larger than the size of the outer peripheral block 328, which can effectively adjust the luminance above the light-emitting chip 210, reinforce the luminance on the outer periphery of the light-emitting chip 210, and improve the uniformity of the luminous efficiency.

[0096] Specifically, the backlight lamp plate selectively includes a transparent second package adhesive layer and a second embossed reflection layer for some light rays to pass through. One surface of the second package adhesive layer is covered by the reflection pattern 300 and the package adhesive layer 130. The second embossed reflection layer is provided on the other surface of the second package adhesive layer. The projection of the air gap of the second embossed reflection layer and the air gap of the reflection pattern 300 onto the substrate 100 overlaps at least partially. That is, the light rays of the light-emitting chip 210 can be adjusted by two or more layers of reflection, which is beneficial to improving the uniformity of light output. The materials and thicknesses of the second embossed reflection layer and the reflection pattern 300 may be the same. In this embodiment, one layer of package adhesive layer and one layer of embossed reflection layer may be used.

[0097] In a specific application, as shown in FIGS. 15 and 16, an optical film 140 may be attached to the lamp plate. The optical film 140 may be located above the package adhesive layer 130. A diffusion pattern 141 may be printed on the surface of the optical film 140. The diffusion pattern 141 of the optical film 140 and the reflection pattern 320 may be alternately arranged. Some light rays are emitted after reciprocally reflecting between the alternately arranged diffusion pattern 141 and reflection pattern 320, which is advantageous for light emission uniformity. The configuration of the diffusion pattern 141 may include a resin and reflective particles dispersed in the resin, similar to the reflection pattern 320.

[0098] In the above embodiments, the reflection pattern may be provided on a single optical film and attached to the package adhesive layer. In this way, optical films with different reflection patterns can be pre-manufactured. An optical film with a specific reflection pattern can be selected according to the application effect and attached to the package adhesive layer, and the optical film can be replaced. It is flexible and convenient to use and has a wide application range. In addition, a diffusion pattern and a reflection pattern may be screen-printed on the front and back surfaces of the same optical film respectively (that is, it is not necessary to provide two optical films, and one optical film is shared as a carrier). The diffusion pattern and the reflection pattern may be alternately provided. During use, the optical film can be directly attached to the package adhesive. It is flexible and convenient to use, has a wide application range, and low cost.

[0099] This embodiment includes a step of manufacturing the substrate 100, a step of providing a circuit layer 110 on the substrate 100, a step of connecting a light-emitting chip 210 (LED chip) to the circuit layer 110 and providing a light reflection layer 120 (first light reflection layer) on the circuit layer 110, a step of covering the light-emitting chip 210 (LED chip) and the light reflection layer 120 (first light reflection layer) with a package adhesive layer 130, A method for manufacturing an LED lamp plate for manufacturing the above backlight lamp plate is further provided, including: providing a reflection pattern 300 for allowing some light rays to pass through and reflecting some light rays on the package adhesive layer 130, and directing the reflection surface of the reflection pattern 300 toward the light emitting surface of the light emitting chip 210. Some of the light rays emitted by the light emitting chip 210 are directed toward the reflection region, while some are directly emitted from the air gap. The light rays directed to the reflection region are reflected in the reflection region to form reflected light rays. Some of the reflected light rays are reflected by the light reflection layer 120 (the first light reflection layer) and then emitted from the air gap and the side surface on the outer peripheral side of the light emitting chip 210. Some of the reflected light rays are reflected and then emitted from the side surface of the light emitting chip 210. In view of the characteristic that the light emission from the central part of the light emitting chip 210 is strong and the light emission from the outer peripheral side is weak, in this embodiment, a watermark engraving structure is opened in the reflection pattern 300 to form an air gap, so as to adjust the ratio and occupancy rate of the air gap area, weaken the light intensity in the central region of the surface of the light emitting chip 210, and increase the light intensity in the side region of the light emitting chip 210. Some of the light emitted by the light emitting chip 210 directly passes through the air gap and is emitted from the surface, and some is reflected by the reflection region, effectively adjusting the luminance above the light emitting chip 210 (i.e., immediately before the light emitting direction), ensuring the light emission efficiency and luminance of the backlight lamp plate. With the action of the reflection pattern 300 and the reflection layer 120 (the first reflection layer), the light emission angle of the light emitting chip 210 is increased, the light emission luminance on the outer peripheral side of the light emitting chip 210 is improved, and the light emission uniformity of the light plate is improved, with good application effects.

[0100] Specifically, the reflection pattern 300 may be formed on the surface of the package adhesive layer 130 by screen printing. The process is simple and reliable, and the size and ratio of the watermark engraving can be accurately controlled, with good product integrity, high production efficiency, and low cost.

[0101] The LED lamp plate according to an embodiment of the present invention is a backlight lamp plate. By providing the reflection pattern 300, a part of the light rays emitted by the light-emitting chip 210 is emitted from the surface of the reflection pattern 300 through the air gap in front of the light-emitting chip 210, and a part of it is reflected in the reflection region to form reflected light rays. After a part of the reflected light rays is reflected by the light reflection layer 120 (the first light reflection layer), it is emitted from the air gap and the side surface on the outer peripheral side of the light-emitting chip 210. After a part of the reflected light rays is reflected, it is emitted from the side surface of the light-emitting chip 210. In view of the characteristics that the light emission at the central part of the light-emitting chip 210 is strong and the light emission at the outer peripheral side is weak, in this embodiment, a watermark engraving structure is formed in the reflection pattern 300 to form an air gap, so as to adjust the ratio and occupancy rate of the air gap area, weaken the light intensity in the central region of the surface of the light-emitting chip 210, and increase the light intensity in the side region of the light-emitting chip 210. A part of the light emitted by the light-emitting chip 210 directly passes through the air gap and is emitted from the surface, and a part is reflected by the reflection region, effectively adjusting the luminance above the light-emitting chip 210 (that is, immediately before the light-emitting direction), ensuring the light-emitting efficiency and luminance of the backlight lamp plate. At the same time, due to the action of the reflection pattern 300 and the reflection layer 120 (the first reflection layer), the light-emitting angle of the light-emitting chip 210 is increased, the light-emitting luminance on the outer peripheral side of the light-emitting chip 210 is improved, the light-emitting uniformity of the light plate is improved, and the application effect is good.

[0102] Example 3 The LED lamp plate according to an embodiment of the present invention, as shown in FIGS. 17 and 18, referring to FIGS. 1 to 3, is used in a mini LED backlight display module and a direct display product. The lamp plate includes a substrate 6, a first package adhesive layer 4, a circuit composite layer, and an LED chip 1. The circuit composite layer includes a circuit layer 3 and a solder resist layer 8. The solder resist layer 8 is provided on the circuit layer 3 and has a window opening structure. The solder resist layer 8 is provided between the circuit layer 3 and the first package adhesive layer 4. A plurality of window opening structures are provided in the solder resist layer 8. The circuit layer 3 is provided on one side of the substrate 6. The circuit layer 3 has pads. The LED chip 1 is connected to the pads. In this embodiment, the LED chip 1 is a flip chip, specifically, a flip blue light LED chip or a flip RGBAn LED chip group, wherein the substrate 6 is an FR4 wiring substrate or a glass substrate, the lamp plate further includes a second package adhesive layer 7, the first package adhesive layer 4 is provided on one side of the substrate 6, covers the LED chip 1 and the circuit layer 3, the first package adhesive layer 4 permits the transmission of light emitted by the LED chip 1, the second package adhesive layer 7 is provided on the other side of the substrate 6, and is used to offset part or all of the stress on the substrate 6 caused by the first package adhesive layer 4. If only the first package adhesive is used to form the first package adhesive layer 4 by means of a dispenser or direct press, the first package adhesive layer 4 has stress acting on the substrate 6, making the substrate 6 prone to deformation. Usually, both ends of the substrate 6 are warped and the middle is sunken, making the LED chip 1 prone to peeling. In this embodiment, the first package adhesive layer 4 and the second package adhesive layer 7 are respectively provided on both sides of the substrate 6, and the first package adhesive layer 4 and the second package adhesive layer 7 form a "sandwich" structure with the substrate 6. Here, the first package adhesive layer 4 has a tensile stress acting on the substrate 6 and directed towards one side of the substrate 6, and the second package adhesive layer 7 has a tensile stress acting on the substrate 6 and directed towards the other side of the substrate 6. Thus, the tensile stresses acting on both sides of the substrate 6 are largely offset, effectively reducing the warping deformation caused by the stress of the package adhesive layer in the substrate 6 (especially the substrate 6), effectively improving problems such as delamination, deformation, and poor airtightness after the lamp plate is sealed, avoiding the risk of defects such as peeling of the LED chip, and the first package adhesive layer 4, the second package adhesive layer 7, and the substrate 6 form a "sandwich" structure, eliminating the need to use multiple layers of package adhesive layers, simplifying the manufacturing process, and reducing costs.

[0103] In specific applications, the projected area of the first package adhesive layer 4 onto the substrate 6 can cover the substrate 6, that is, the first package adhesive layer 4 can completely cover one side surface of the substrate 6, or the first package adhesive layer 4 consists of non - contacting first segment adhesive layers. The first package adhesive can be formed by a dispenser on one side of the substrate 6 (specifically, one side of the circuit layer 3 and the top of the LED chip 1) to form non - contacting first segment adhesive layers of a plurality of segments. In other embodiments, the second package adhesive layer 7 consists of non - contacting second segment adhesive layers. By forming non - contacting second segment adhesive layers of a plurality of segments by dispensing the second package adhesive on the other side of the substrate 6, the stress between the substrates 6 located on both sides of the segment adhesive layer can be offset, and the deformation of the substrate 6 can be prevented. As a preferred embodiment, the first package adhesive layer 4 completely covers one side of the substrate 6, and the second package adhesive layer 7 partially covers the other side of the substrate 6. In this way, other elements may be attached to the back surface of the substrate 6 with a space reserved in advance.

[0104] In specific applications, the thickness of the first package adhesive layer 4 is not less than the thickness of the second package adhesive layer 7. Specifically, the first package adhesive layer 4 located on one side of the substrate 6 serves to cover the LED chip 1 and requires a certain thickness. The second package adhesive layer 7 located on the other side of the substrate 6 is an additional thickness, which will increase the overall thickness of the product and does not meet the market requirement that the entire LED module becomes thinner. By controlling the thickness of the second package adhesive layer 7 to be smaller than the thickness of the first package adhesive layer 4, the overall thickness of the lamp plate becomes smaller, the miniaturization of the device can be achieved, which is beneficial for meeting the market requirements.

[0105] In a specific application, the thickness of the first package adhesive layer 4 is greater than the thickness of the second package adhesive layer 7. The first package adhesive layer 4 has a first coefficient of thermal expansion, and the second package adhesive layer 7 has a second coefficient of thermal expansion that is greater than the first coefficient of thermal expansion. The product of the thickness of the first package adhesive layer 4 and the first coefficient of thermal expansion is A, and the product of the thickness of the second package adhesive layer 7 and the second coefficient of thermal expansion is B. A is equal to or approximately equal to B. Note that when the thickness of the first package adhesive layer 4 is large and the first coefficient of thermal expansion is small, while the thickness of the second package adhesive layer 7 is small and the first coefficient of thermal expansion is large, the stresses acting on both sides of the substrate 6 can be balanced and offset. At the same time, the first package adhesive layer 4 has a certain thickness and serves to cover the LED chip. The thickness of the second package adhesive layer 7 is relatively small, which is convenient for thinning the lamp plate. As another embodiment, the thickness of the first package adhesive layer 4 is equal to the thickness of the second package adhesive layer 7. The first package adhesive layer 4 has a first coefficient of thermal expansion, and the second package adhesive layer 7 has a second coefficient of thermal expansion that is the same as the first coefficient of thermal expansion. In a specific application, the most important parameters for the magnitude of the stress exerted by the package adhesive layer on the substrate 6 are the thickness and the coefficient of thermal expansion of the package adhesive layer. In a specific application, package adhesive materials with different coefficients of thermal expansion can be selected according to the thickness of the package adhesive layer, which provides flexible control, offsets the stresses acting on both sides of the substrate 6, and tends to make the entire product thinner.

[0106] Furthermore, the materials of the first package adhesive layer 4 and the second package adhesive layer 7 are the same, either epoxy resin or silicone resin, which is advantageous for cost reduction. In other embodiments, the materials of the first package adhesive layer 4 and the second package adhesive layer 7 may be different. Inorganic light-transmitting particles 5 for adjusting its coefficient of thermal expansion are dispersedly provided in the first package adhesive layer 4. By adding inorganic light-transmitting particles to the package adhesive, the coefficient of thermal expansion of the package adhesive layer can be adjusted, which is convenient for adjustment and has a low cost. When the inorganic light-transmitting particles 5 settle in the first package adhesive layer 4, the content of the inorganic light-transmitting particles 5 gradually decreases along the direction away from the substrate, that is, the added inorganic light-transmitting particles 5 naturally settle in the first package adhesive, and the coefficient of thermal expansion is smaller in the region closer to the substrate 6, and the deformation of the substrate 6 can be effectively reduced. The particle size range of the inorganic light-transmitting particles 5 is 50 nm to 5 μm. Since the inorganic light-transmitting particles 5 can transmit light, it is advantageous for ensuring the light emission of the LED chip. In this embodiment, the inorganic light-transmitting particles 5 are silica powder or alumina powder, or a mixture of silica powder or alumina powder is used, and the inorganic light-transmitting particles 5 are added to the first package adhesive layer 4. In this embodiment, preferably, the particle size range of the inorganic light-transmitting particles 5 is 100 nm to 1 μm, and silica is the main component of glass, and alumina is the main component of sapphire. Both silica powder and alumina powder are light-transmitting particles. The proportion of silica powder or alumina powder in the first package adhesive layer 4 is 20% to 60%. By controlling the standing time before the first package adhesive is cured, the silica powder or alumina powder naturally settles in the first package adhesive, showing a step distribution, and the content is higher in the region closer to the substrate 6, that is, the coefficient of thermal expansion is smaller in the region closer to the substrate 6, and the deformation of the substrate 6 is further reduced. Alternatively, the projected area of the package adhesive layer located on the other side of the substrate 6 on the substrate 6 can be flexibly adjusted. Due to cost factors, it does not necessarily completely cover the other side of the substrate 6. Using light-transmitting particles does not affect the light emission of the LED chip 1, and the coefficient of thermal expansion is adjusted, with good adjustment effect and low cost.

[0107] As a preferred embodiment, the thickness range of the first package adhesive layer 4 is 150 μm to 400 μm, and / or the thickness range of the second package adhesive layer 7 is 20 μm to 200 μm. In a specific application, the thickness of the first package adhesive layer 4 is not less than the thickness of the second package adhesive layer 7, and preferably the thickness range of the first package adhesive layer 4 is 250 μm to 300 μm. The first package adhesive layer 4 may be made of an epoxy resin or a silicone resin, and the second package adhesive layer 7 may also be made of either an epoxy resin or a silicone resin.

[0108] Furthermore, as shown in FIGS. 17 and 18, at least a pair of the pads are provided in the region corresponding to each of the window opening structures, the LED chip 1 is provided in the window opening structure and connected to the pads in the corresponding window opening structure, and the first package adhesive layer 4 is in direct contact with the substrate through the window opening structure. Specifically, the first package adhesive layer 4 includes an external package adhesive layer located on the outer peripheral side of the LED chip 1 and a bottom package adhesive layer located in the window opening structure. The bottom package adhesive layer is formed by filling the window opening structure with the first package adhesive and is directly connected to the substrate 6. This not only facilitates die bonding, but also improves the light emission efficiency, is advantageous for improving the backlight brightness, improves the yield of the manufacturing process, and has a low manufacturing cost.

[0109] The embodiments of the present invention include a step of manufacturing a substrate 6 that can be an FR4 wiring board or a glass board, A circuit layer 3 having pads is provided on the substrate 6. In a specific application, a solder resist layer 8 is further provided above the circuit layer 3. By providing the solder resist layer 8 in other regions of the circuit layer other than the pads, it has an insulating and oxidation-preventing effect. The solder resist layer 8 is generally created by ink. When applied to a backlight product, it is created by white ink, and when applied to a direct display product, it is created by black ink. And connecting the LED chip 1 to the pad. In a specific application, a solder paste layer 2 may be provided on the pad to facilitate soldering. Further provided is a method for manufacturing an LED lamp plate for manufacturing the above-mentioned LED lamp plate, which includes these steps.

[0110] As shown in FIG. 17, a first package adhesive layer 4 for covering the LED chip 1 and the circuit layer 3 is formed by a first package adhesive on one side of the substrate 6. Specifically, the first package adhesive is provided on one side of the substrate 6 by a dispenser or a direct press method and then cured and formed to form the first package adhesive layer 4.

[0111] As shown in FIG. 18, a second package adhesive layer 7 made of a second package adhesive is provided on the other side of the substrate 6. Specifically, the second package adhesive is provided on the other side of the substrate 6 by a dispenser or a direct press method and then cured and formed to form the second package adhesive layer 7. By forming a "sandwich" structure with the substrate 6 by the first package adhesive layer 4 and the second package adhesive layer 7, the tensile stresses acting on both sides of the substrate 6 are largely offset, effectively reducing the warping deformation caused by the stress of the package adhesive layer in the substrate 6 (especially the substrate 6), effectively improving problems such as delamination, deformation, and poor airtightness after the lamp plate is sealed, and avoiding the risk of defects such as peeling of the LED chip.

[0112] The LED lamp plate and its manufacturing method according to the embodiment of the present invention are such that the first package adhesive layer 4 is provided on one side of the substrate 6 and covers the LED chip 1 and the circuit layer 3, and the second package adhesive layer 7 is provided on the other side of the substrate 6. By forming a "sandwich" structure with the substrate 6 by the first package adhesive layer 4 and the second package adhesive layer 7, the stresses acting on both sides of the substrate 6 are largely offset, effectively reducing problems such as warping deformation due to the stress of the substrate 6, effectively improving delamination, deformation, and poor airtightness after the lamp plate is sealed, avoiding the risk of defects such as peeling of the LED chip, and having a low production cost.

[0113] Example 4 As shown in FIGS. 20 to 23, the LED lamp plate according to an embodiment of the present invention includes a substrate 1, a circuit composite layer (including a circuit layer 2 and a solder resist layer 3 provided on the circuit layer 2 and having a window opening structure), a solder resist layer 3, an LED chip 4, and a colored adhesive layer 5. The circuit layer 2 is provided on the substrate 1. The solder resist layer 3 has at least one window opening structure. The solder resist layer 3 is provided on the circuit layer 2. Specifically, the solder resist layer 3 is located on the top and the outer peripheral side of the circuit layer 2, and at least a part thereof covers the outer peripheral edge of the circuit layer 2. The LED chip 4 is located in the window opening structure and is connected to the circuit layer 2. In a specific application, a plurality of the LED chips 4 may be provided, and a plurality of window opening structures may be correspondingly provided in the solder resist layer 3. One of the LED chips 4 is provided in each window opening structure. The colored adhesive layer 5 is filled in the window opening structure. As shown in FIG. 20, the colored adhesive layer 5 is connected to the LED chip 4 and the solder resist layer 3 respectively. Specifically, the colored adhesive layer 5 may be connected to the outer peripheral side of the LED chip 4, and the side surface of the colored adhesive layer 5 may be connected to the solder resist layer 3. Or, in another embodiment, as shown in FIG. 21, a part of the colored adhesive layer 5 covers the top of the solder resist layer 3. The color of the colored adhesive layer 5 is the same as the color of the solder resist layer 3. Specifically, in one embodiment, when the LED lamp plate is used in a white light LED product, the colored adhesive layer 5 is a white adhesive layer. By providing the white adhesive layer in the window opening structure, a part of the circuit layer 2 on the outer periphery of the LED chip 4 can be covered. When the LED chip 4 emits light, by providing the white adhesive layer on the outer periphery of the LED chip 4, the reflectivity of the outer peripheral region of the LED chip 4 is improved, and the light reflection effect is enhanced, so that the emission luminance of the white light LED product is improved. It is not necessary to change the size of the lamp beads and the size of the LED chip 4, nor is it necessary to improve the light emission efficiency of the chip. The luminance of the white LED can be effectively improved, the improvement effect is good, and the cost is low. In another embodiment of the present invention, the LED lamp plate is used in an RGB-LED direct display product. The solder resist layer is black, and the colored adhesive layer 5 is a black adhesive layer. The blackness of the black adhesive layer can be adjusted to ensure that it sufficiently matches the black color of the solder resist layer, reduce the light reflection in the outer peripheral region of the RGB-LED chip 4, and effectively improve the contrast. In another embodiment, the LED lamp plate is used in a single-color light LED product. The colored adhesive layer 5 is a colored adhesive layer of a color system corresponding to the color of the solder resist layer. For example, the LED lamp plate may be a red light LED product, and the colored adhesive layer 5 is a red adhesive layer, which is not mixed with other colors to ensure the light emission purity. Of course, the LED lamp plate may also be other single-color light LED products such as blue and green, and the colored adhesive layer 5 may be provided corresponding to the blue adhesive layer and the green adhesive layer. In the LED lamp plate according to an embodiment of the present invention, the top of the LED chip 4 is exposed from the substrate 1, and the colored adhesive layer 5 having the same color as the solder resist layer 3 can completely cover the remaining area of the substrate 1. That is, in addition to being provided with a window opening structure, the colored adhesive layer 5 can also cover the outer peripheral region of the LED chip 4, effectively improving the color consistency of the sealed substrate surface. Different colored colloids can be applied according to different situations to improve the light emission luminance or the contrast. In a specific application, when used in a white light LED product, using a white adhesive layer can improve the light reflection effect in the outer peripheral region of the LED chip 4 and effectively improve the luminance of the white light. When used in an RGB-LED direct display product, using a black adhesive layer can reduce the light reflection in the outer peripheral region of the RGB-LED chip, reduce the light reflection effect, and effectively improve the contrast. When used in a single-color LED product, using the colored adhesive layer 5 of the corresponding color system can prevent other colors from being mixed into the light emitted by the LED chip 4 and ensure the light emission purity.

[0114] Furthermore, the upper ends of the colored adhesive layer 5 and the solder resist layer 3 are both lower than the upper end of the LED chip 4. The top of the LED chip 4 is exposed, and a sufficiently large light-emitting area for reflecting the LED chip 4 is formed on the outer periphery. The colored adhesive layer 5 is higher than the height of the solder resist layer 3, and the height of the colored adhesive layer 5 is lower than the height of the LED chip 4. That is, the top of the colored adhesive layer 5 may be located between the top surface of the solder resist layer 3 and the top surface of the LED chip 4.

[0115] Furthermore, the thickness range of the solder resist layer 3 is 20 μm to 50 μm. In this embodiment, the thickness of the solder resist layer 3 is 30 μm. In a specific application, the solder resist layer 3 and the window opening structure may be formed simultaneously (by an etching process). The solder resist layer 3 is formed by curing solder resist ink.

[0116] Furthermore, the LED lamp plate is provided on the top of the solder resist layer 3 and the top of the colored adhesive layer 5, and further includes a package adhesive layer 6 covering the LED chip 4. Specifically, the package adhesive layer 6 covers the LED chip 4 and covers the conductor (gold wire) for connecting between the LED chip 4 and the circuit layer 2. The package adhesive layer 6 may be a transparent adhesive layer, and the transparent adhesive layer is formed by packaging with a transparent adhesive. In the embodiment according to the present invention, for the lamp beads of the display, the brightness of the product can be improved under the condition that the transparent adhesive is sealed, or the visual effect of the lamp beads can be completely blackened under the condition that the transparent adhesive is sealed, thereby greatly improving the contrast.

[0117] Furthermore, the material of the colored adhesive layer 5 is the same as that of the package adhesive layer 6, which can avoid the generation of gaps or repulsion due to material differences at the contacting parts, making the connection parts adhere more closely. Both the colored adhesive layer 5 and the package adhesive layer 6 may use epoxy resin, or in another embodiment, both may be made of silica gel, which has low cost and good stability.

[0118] Furthermore, the colored adhesive layer 5 is made of a colored ink or a colored colloid with a viscosity of less than 2000 mPa·S. Specifically, the colored adhesive layer 5 is formed by coagulation with a colored colloid, and the viscosity of the colored colloid is crucial as it affects its fluidity. Toner (i.e., colored colloid) is sprayed onto the peripheral functional area (i.e., the window opening structure) around the LED chip 4, and the viscosity range of the toner is 0 - 2000 mPa·S. Due to the liquid surface tension and capillary action of the colored colloid, the colored colloid spreads evenly and flatly on the bottom surface of the lamp beads. By controlling the usage amount of the colored colloid, after the colored colloid hardens, the functional areas except for the LED chip 4 at the bottom of the substrate 1 (in this embodiment, a PCB substrate) are all covered with the colored colloid, and the color of the functional area changes according to the color of the colored colloid.

[0119] Furthermore, as shown in FIGS. 23 and 24, the inner wall of the window opening structure or the circuit layer has a rounded or chamfered structure. Specifically, in this embodiment, the lower end and the upper end of the inner wall of the window opening structure have a rounded structure 7, and the rounded structure 7 may be replaced with a chamfered structure. Both can improve the combination of the colored adhesive layer 5 and the inner wall of the window opening structure and avoid the generation of bubbles and cavities. The inner wall of the circuit layer 3 may have a rounded structure 8. Specifically, the inner wall of the window opening structure may have any of a curved surface, an inclined surface, or a rough surface. The lower end and the upper end of the inner wall of the window opening structure extend in opposite directions to ensure that there is no gap at the joint surface between the colored adhesive layer 5 filled with the colored colloid and the inner wall of the window opening structure. The window opening structures are plural, and one or more of the LED chips 4 are face-up or flip-chip, and are fixed in each of the window opening structures. The LED lamp plate may be applied to conventional lamp beads or to mini COB products.

[0120] An embodiment of the present invention includes a step of manufacturing a substrate 1 which is a PCB substrate; a step of providing a circuit layer 2 on the substrate 1; providing a solder resist layer 3 having a window opening structure on the substrate 1. Specifically, the window opening structure may be formed by an etching process. The solder resist layer 3 is located on the outer peripheral side of the circuit layer 2 and at least partially covers the outer peripheral edge of the circuit layer 2. In a specific application, the solder resist layer 3 and the window opening structure may be formed synchronously. More specifically, the thickness range of the solder resist layer 3 is 20 μm to 50 μm; providing the LED chip 4 in the window opening structure and connecting the LED chip 4 to the circuit layer 2. In a specific application, the connection between the LED chip 4 and the circuit layer 2 may be realized by a conducting wire (gold wire); filling the window opening structure with a colored colloid or colored ink of the same color as the solder resist layer 3 to form a colored adhesive layer 5. The colored adhesive layer 5 is connected to the LED chip 4 and the solder resist layer 3 respectively. In this embodiment, the colored adhesive layer 5 may be connected to the outer peripheral side of the LED chip 4. In one embodiment, the side surface of the colored adhesive layer 5 is connected to the solder resist layer 3. Or, in another embodiment, the colored adhesive layer 5 may be partially covered on the top of the solder resist layer 3; There is further provided a manufacturing method for manufacturing the above LED lamp plate including the above steps.

[0121] The LED lamp plate and its manufacturing method according to the embodiments of the present invention are such that the LED chip 4 is exposed from the substrate 1, and in addition to the colored adhesive layer 5 having the same color as the solder resist layer 3 being connected to the LED chip 4 and the solder resist layer 3 respectively, the colored adhesive layer 5 can completely cover the remaining area of the substrate 1, that is, the colored adhesive layer 5 is filled in the windowed structure, and can also cover the outer peripheral area of the LED chip 4, effectively improving the color consistency of the sealed substrate surface. Different colored colloids can be applied according to different situations to improve the luminous brightness or improve the contrast. When the LED package structure is used in white light LED products, using a white adhesive layer can strengthen the light reflection effect in the outer peripheral area of the LED chip 4 and effectively improve the brightness of white light. When the LED package structure is used in RGB-LED direct display products, using a black adhesive layer can reduce the light reflection in the outer peripheral area of the RGB-LED chip, reduce the light reflection effect, and effectively improve the contrast. When used in monochromatic light LED products, using a colored adhesive layer 5 in the color system corresponding to the color of the solder resist layer can prevent the light emitted by the LED chip 4 from being mixed with light of other colors and ensure the light output purity.

[0122] The above are only preferred embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should all be included within the scope of the present invention.

Claims

1. An LED lamp plate including a substrate and an LED chip, wherein a circuit composite layer having pads for connecting to the LED chip is provided on the substrate. The LED lamp plate is characterized by this.

2. The circuit composite layer includes a circuit layer provided with a first light reflection layer, a plurality of window-opening structures are provided on the first light reflection layer, at least a pair of the pads are provided in a region corresponding to each of the window-opening structures, the LED chip is provided in the window-opening structure and connected to the pads in the corresponding window-opening structure, and an accommodation region is formed between the outer peripheral side of the LED chip and the inner peripheral side of the window-opening structure, the LED lamp plate further includes a second light reflection layer filled in the accommodation region. The LED lamp plate according to claim 1 is characterized by this.

3. The circuit composite layer includes a circuit layer and a solder resist layer provided on the circuit layer and having a window-opening structure, at least a pair of the pads are provided in a region corresponding to each of the window-opening structures, the LED chip is provided in the window-opening structure and connected to the pads in the corresponding window-opening structure, the LED lamp plate further includes a first package adhesive layer, the first package adhesive layer is provided on one side of the substrate and covers the LED chip and the circuit composite layer, the first package adhesive layer permits transmission of light emitted by the LED chip, the LED lamp plate further includes a second package adhesive layer provided on the other side of the substrate for partially or entirely canceling the stress on the substrate by the first package adhesive layer. The LED lamp plate according to claim 1 is characterized by this.

4. The circuit composite layer includes a circuit layer and a solder resist layer provided on the circuit layer and having a window-opening structure, at least a pair of the pads are provided in a region corresponding to each of the window-opening structures, the LED chip is provided in the window-opening structure and connected to the pads in the corresponding window-opening structure, the LED chip is located in the window-opening structure and connected to the circuit layer, the LED lamp plate further includes a colored adhesive layer The colored adhesive layer is filled in the window opening structure, and the colored adhesive layers are respectively connected to the LED chip and the solder resist layer, and the color of the colored adhesive layer and the color of the solder resist layer are the same. The LED lamp plate according to claim 1, characterized in that.

5. The second light reflection layer is made of resin, and light reflection particles are dispersed in the second light reflection layer. The LED lamp plate according to claim 2, characterized in that.

6. The second light reflection layer is formed by dispensing in the window opening structure. The LED lamp plate according to claim 5, characterized in that.

7. The LED chip is a flip chip, and there is a gap between the surface of the LED chip facing the substrate and the substrate. The second light reflection layer includes a side surface light reflection portion in contact with the outer peripheral side of the LED chip and a bottom surface light reflection portion filled in the gap. The LED lamp plate according to claim 2, characterized in that.

8. A solder paste layer for connecting to the LED chip is provided on the surface of the pad. The second light reflection layer covers the periphery of the connection portion between the LED chip and the solder paste layer. The LED lamp plate according to claim 2, characterized in that.

9. The top surface of the first light reflection layer is located between the bottom surface and the top surface of the LED chip. The top surface of the second light reflection layer is not higher than the top surface of the first light reflection layer. The LED lamp plate according to claim 2, 5, 6, 7 or 8, characterized in that.

10. The reflectivity of the second light reflection layer is greater than the reflectivity of the first light reflection layer. The LED lamp plate according to claim 2, characterized in that.

11. The first light reflection layer is made of white ink. The LED lamp plate according to claim 2, characterized in that.

12. The thickness range of the first light reflection layer is 20 μm to 80 μm. The LED lamp plate according to claim 2, characterized in that.

13. The size of the window opening structure is satisfies the relationship of Bx <Px, By <Py, where Bx represents the maximum size in the horizontal direction of the window opening structure, By represents the maximum size in the vertical direction of the window opening structure, Px represents the horizontal pitch between two adjacent LED chips. Py represents the vertical pitch between two adjacent ones of the LED chips, The LED lamp plate according to claim 2, characterized in that.

14. The window opening structure is a rectangular through-hole, The LED lamp plate according to claim 3, characterized in that the longitudinal size of the rectangular through-hole is 2 mm or more.

15. A plurality of the LED chips are provided, The LED lamp plate further includes a plurality of reflection patterns, The second light reflection layer is coated above the substrate and the LED chips, The reflection pattern is provided on the upper surface of the second light reflection layer, The reflection pattern includes a plurality of reflection means provided at intervals, An air gap is formed between the reflection means, The reflection means includes a resin and reflection particles dispersed in the resin, The density of the reflection particles in the central region of the reflection pattern is greater than the density of the reflection particles in the outer peripheral region of the reflection pattern, The first light reflection layer is provided on the surface of the circuit composite layer to which the LED chips are connected, One surface of the second light reflection layer is coated by the first light reflection layer and the LED chips, The LED lamp plate according to claim 2, characterized in that.

16. In one of the reflection patterns, the area of the air gap occupies 20% to 80% of the area of the contour of the reflection pattern, and / or The thickness of the reflection pattern is 10 μm to 60 μm, The LED lamp plate according to claim 15, characterized in that.

17. The reflection means includes a reflection ring located in the central region of the reflection pattern, The LED lamp plate according to claim 15, characterized in that.

18. The reflection means includes a plurality of the reflection rings provided with the same center and having an interval between adjacent ones of the reflection rings, The LED lamp plate according to claim 17, characterized in that.

19. Reflection points are provided on the outer periphery of the reflection ring, and the distribution density of each of the reflection points becomes smaller as the distance from the center of the reflection pattern increases, The LED lamp plate according to claim 18, characterized in that.

20. The reflection means includes a plurality of reflection points surrounding the center of the reflection pattern, and the area of the reflection points becomes smaller as the distance from the center of the reflection pattern increases, The LED lamp plate according to claim 15, characterized in that.

21. The reflectivity of the reflecting means in the central region of the reflection pattern is greater than the reflectivity of the reflecting means in the outer peripheral region of the reflection pattern. The LED lamp plate according to claim 15, characterized in that.

22. The reflecting means in the central region of the reflection pattern contains titanium dioxide particles, and the reflecting means in the outer peripheral region of the reflection pattern contains silica particles. The LED lamp plate according to claim 21, characterized in that.

23. The reflection pattern is formed by screen printing, and a release slope is provided on the side wall of the reflecting means. The LED lamp plate according to claim 15, characterized in that.

24. It further includes an optical film provided above the second light reflection layer, a diffusion pattern is printed on the surface of the optical film, and the diffusion pattern of the optical film and the reflection pattern are arranged alternately. The LED lamp plate according to claim 15, characterized in that.

25. The thickness of the first package adhesive layer is greater than the thickness of the second package adhesive layer. The first package adhesive layer has a first coefficient of thermal expansion, and the second package adhesive layer has a second coefficient of thermal expansion greater than the first coefficient of thermal expansion. The LED lamp plate according to claim 3, characterized in that.

26. The materials of the first package adhesive layer and the second package adhesive layer are the same, and both are epoxy resin or silicone resin. The LED lamp plate according to claim 25, characterized in that.

27. Inorganic light-transmitting particles for adjusting its coefficient of thermal expansion are dispersedly provided in the first package adhesive layer. The LED lamp plate according to claim 25, characterized in that.

28. Due to the sedimentation of the inorganic light-transmitting particles in the first package adhesive layer, the content of the inorganic light-transmitting particles gradually decreases along the direction away from the substrate. The LED lamp plate according to claim 27, characterized in that.

29. The particle size range of the inorganic light-transmitting particles is 50 nm to 5 μm. The LED lamp plate according to claim 27, characterized in that.

30. The inorganic light-transmitting particles are at least one of silica powder or alumina powder. The LED lamp plate according to claim 27, characterized in that.

31. The thickness range of the first package adhesive layer is 150 μm to 400 μm, and / or the thickness range of the second package adhesive layer is 20 μm to 200 μm. The LED lamp plate according to claim 3, characterized in that.

32. The first package adhesive layer is in direct contact with the substrate through the window opening structure. The LED lamp plate according to claim 3, characterized in that.

33. The upper ends of both the colored adhesive layer and the solder resist layer are lower than the upper end of the LED chip. The LED lamp plate according to claim 4, characterized in that.

34. The thickness range of the solder resist layer is 20 μm to 50 μm. The LED lamp plate according to claim 4, characterized in that.

35. The LED lamp plate further includes a package adhesive layer provided on the top of the solder resist layer and the top of the colored adhesive layer and covering the LED chip. The LED lamp plate according to claim 4, characterized in that.

36. The materials of the colored adhesive layer and the package adhesive layer are the same, and both are epoxy resin or silica gel. The LED lamp plate according to claim 35, characterized in that.

37. The colors of the colored adhesive layer and the solder resist layer are white or black. The LED lamp plate according to claim 4, characterized in that.

38. The colored adhesive layer is made of a colored ink or a colored colloid with a viscosity of less than 2000 mPa·s. The LED lamp plate according to claim 4, characterized in that.

39. The inner wall of the window opening structure or the circuit layer has a rounded or chamfered structure. The LED lamp plate according to claim 38, characterized in that.

40. There are a plurality of the window opening structures, and one or more of the LED chips are face-up or flip-chip and are fixed in each of the window opening structures. The LED lamp plate according to claim 4, characterized in that.

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