A substrate for making LED lamp beads and LED lamp beads thereof

Abstract

The utility model discloses a kind of substrate for making LED lamp pearl and its LED lamp pearl, it is related to LED lamp pearl technical field, including sapphire substrate, along the thickness direction of the sapphire substrate, the sapphire substrate has the first board face and the second board face of relative arrangement;Reflection layer, the reflection layer is set on the first board face;And, heat dissipation layer, the heat dissipation layer is set on the second board face.The reflection layer is set on the first board face of sapphire substrate, to reduce transmission and reduce luminance absorption rate, improve the overall brightness of sapphire substrate, and heat dissipation layer is set on the second board face of sapphire substrate, enhance sapphire substrate heat dissipation capacity, reduce the possibility of sapphire substrate local overheating, simultaneously as the sapphire of substrate itself has the characteristics of good light transmission, light transmission performance, can solve the problem of lower product service life in the prior art that luminance loss is larger when LED lamp pearl emits light.

Description

Technical Field

[0001] This utility model relates to the field of LED lamp beads, specifically to a substrate for manufacturing LED lamp beads and the LED lamp beads thereof. Background Technology

[0002] With the development of LEDs and the increasing maturity of packaging technology, LED screens are finding wider and wider applications in the market, appearing more and more frequently in people's lives. Consequently, the requirements and standards for their display effects are becoming increasingly stringent, leading to a diverse range of research and development efforts focused on new materials, such as ceramics, iron, copper, and aluminum as substrates. Currently, the mainstream LED packaging on the market mostly uses BT substrates (Bismaleimide Triazine substrates). This material is composed of bismaleimide and triazine resin, possessing properties such as high temperature resistance and dimensional stability, and is widely used in the electronic packaging field.

[0003] As a non-transparent material, BT substrate has low light transmittance, resulting in significant brightness loss when LED chips emit light, which seriously affects the brightness of the chips. Furthermore, when the packaging temperature exceeds 150°C, BT substrate is prone to deformation and is easily oxidized and corroded under long-term high-temperature environment, reducing the product's lifespan. Utility Model Content

[0004] This application provides a substrate for manufacturing LED beads and its encapsulation of LED beads, which can solve the technical problems of large brightness loss and short product lifespan of LED beads in the prior art.

[0005] In a first aspect, embodiments of this application provide a substrate for manufacturing LED lamp beads, comprising:

[0006] A sapphire substrate, along the thickness direction of the sapphire substrate, has a first plate surface and a second plate surface arranged opposite to each other;

[0007] A reflective layer is disposed on the surface of the first plate;

[0008] And a heat dissipation layer disposed on the second plate surface.

[0009] In conjunction with the first aspect, in one embodiment, a substrate for manufacturing LED beads further includes:

[0010] A circuit layer is disposed on the surface of the reflective layer away from the first board surface;

[0011] The circuit layer is divided into pixel areas, and the circuit layer is provided with a first pad and a second pad for soldering to the pins of the RGB chip corresponding to the pixel areas.

[0012] The first pad and the second pad have opposite polarities.

[0013] In conjunction with the first aspect, in one embodiment, the chip workstation includes:

[0014] Within the pixel area, there is one first pad and three second pads;

[0015] The length of the first pad extends along a first direction, and each of the second pads is distributed along the first direction;

[0016] The first pad and the second pad are spaced apart along a second direction;

[0017] Wherein, the first direction is one of the length and width of the sapphire substrate, and the second direction is the other of the length and width of the sapphire substrate.

[0018] In conjunction with the first aspect, in one embodiment, the pixel region includes at least a first pixel region and a second pixel region, wherein the first pixel region and the second pixel region share the first pad or the second pad.

[0019] In conjunction with the first aspect, in one embodiment, the pixel region includes at least a first pixel region, a second pixel region, and a third pixel region, two of the three pixel regions share the first pad, and one of the two pixel regions shares the second pad with the remaining pixel region among the first, second, and third pixel regions.

[0020] In conjunction with the first aspect, in one embodiment, a solder mask is further provided on the circuit layer, and the solder mask is located between the first pad and the second pad, or between the first pad and the second pad.

[0021] In conjunction with the first aspect, in one embodiment, the heat dissipation layer comprises a diamond film.

[0022] Secondly, embodiments of this application provide an LED lamp bead, which includes:

[0023] Any of the above-mentioned substrates used for manufacturing LED beads.

[0024] In conjunction with the second aspect, in one embodiment, an LED lamp bead further includes:

[0025] An encapsulation layer is disposed on the reflective layer, and an RGB chip is disposed within the encapsulation layer;

[0026] And a protective layer disposed on the encapsulation layer.

[0027] In conjunction with the second aspect, in one embodiment, the encapsulation layer is made of epoxy resin, and a diffusion powder is disposed within the encapsulation layer.

[0028] The beneficial effects of the technical solutions provided in this application include:

[0029] By setting a reflective layer on the first surface of the sapphire substrate to reduce transmission and lower the brightness absorption rate, the overall brightness of the sapphire substrate is improved. A heat dissipation layer is set on the second surface of the sapphire substrate to enhance the heat dissipation capacity of the sapphire substrate and reduce the possibility of local overheating. At the same time, sapphire itself, as the substrate, has good light transmittance. The light transmittance can solve the problems of large brightness loss and short product lifespan of LED lamp beads in the existing technology. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a top view of a sapphire substrate used for manufacturing LED beads according to this application;

[0032] Figure 2 A top view of a sapphire substrate with three pixel regions as defined in this application;

[0033] Figure 3 This is a schematic diagram of the structure of a packaged LED bead in this application;

[0034] In the figure: 1. Sapphire substrate; 11. First board surface; 12. Second board surface; 2. Reflective layer; 3. Heat dissipation layer; 4. Circuit layer; 41. Second pad; 42. First pad; 43. Solder resist; 44. First pixel area; 45. Second pixel area; 46. Third pixel area; 5. Encapsulation layer; 6. Protective layer; 7. RGB chip. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present application.

[0036] This application provides a substrate for manufacturing LED beads and the LED beads thereon, which can solve the problems of large brightness loss and short product lifespan of LED beads when emitting light in the prior art.

[0037] Reference Figure 1 This application discloses a substrate for manufacturing LED chips, comprising a sapphire substrate 1, a reflective layer 2, and a heat dissipation layer 3. The sapphire substrate 1 has two opposing surfaces, one being a first surface 11 and the other a second surface 12, which are opposite to each other. The reflective layer 2 is disposed on the first surface 11, and the heat dissipation layer 3 is disposed on the second surface 12. During subsequent LED chip processing using the substrate, the first surface 11 is used to mount the RGB chip 7. The reflective layer 2 is disposed on the first surface 11 of the sapphire substrate 1 to reduce transmission and decrease brightness absorption, thereby improving the overall brightness of the sapphire substrate 1. The heat dissipation layer 3 is disposed on the second surface 12 of the sapphire substrate 1 to enhance its heat dissipation capacity and reduce the possibility of localized overheating. Simultaneously, the sapphire used to manufacture the substrate has a transmittance exceeding 85% in the visible light band, inherently possessing excellent light transmittance, which can significantly reduce light loss and improve LED brightness, solving the problems of significant brightness loss and short product lifespan in existing LED chips.

[0038] In one embodiment of this application, the material used for the reflective layer 2 can be selected from various options depending on the actual situation. For example, it can be made of a composite metal layer. Specifically, a distributed Bragg reflector (i.e., a DBR dielectric layer) stacked with a metal composite layer can be used. Through the synergistic effect of multiple dielectric films and metal films, dual optimization of optical reflection and electrical conduction can be achieved. The DBR deposition requires a physical vapor deposition (PVD) process. First, an alternating stack of oxides SiO2 and TiO2 is used to form the DBR dielectric layer. Then, metals Al and Ag are stacked on the DBR dielectric layer to form a metal composite layer, further enhancing reflection and assisting in conductivity. The specific operation process includes: cleaning the substrate with ultrasonic acetone, isopropanol, and deionized water, and evacuating to a vacuum level ≤5×10⁻⁶. -6The process involves using a torsion process to avoid contamination, followed by sputtering / evaporation deposition of metallic materials such as Ag and Al. Finally, photolithography is used to define the electrode pattern, thus completing the fabrication of the reflective layer 2. Reflective layer 2 improves light reflectivity and enhances light efficiency. Its use in high-end products, such as transparent screens, allows for seamless integration with the environment and provides excellent concealment.

[0039] The material used for the heat dissipation layer 3 can be selected from various options depending on the specific circumstances. For example, it can be made of diamond film, which has the highest thermal conductivity in nature, more than five times that of copper. Specifically, the heat dissipation layer 3 can be fabricated by chemical vapor deposition (CVD) to coat the second surface 12 of the sapphire substrate 1 with a diamond film. Compared to traditional physical vapor deposition (PVD), CVD can deposit a uniform diamond film on a large-area sapphire substrate 1. Furthermore, the lower deposition temperature of CVD reduces the likelihood of deformation during the formation of the heat dissipation layer 3 on the sapphire substrate 1. Simultaneously, CVD allows for the controllable grain size of the diamond film, enabling micron- to nanometer-scale grain growth and achieving highly oriented polycrystalline diamond film. Moreover, by adjusting the gas ratio during CVD, such as by adding small amounts of oxygen or nitrogen, controllable doping elements can be introduced, further optimizing the electrical and thermal properties of the diamond film.

[0040] Diamond, with its unique face-centered cubic structure, exhibits exceptional thermal conductivity, unparalleled in nature. Specifically, diamond has a thermal conductivity of 2000 W / m·K, five times that of pure copper, 2000 times that of aluminum oxide, and even higher than that of aluminum nitride. This superior thermal conductivity primarily stems from the rigid lattice structure formed by strong covalent bonds within the diamond crystal, resulting in a long phonon transport path and a low scattering probability, thus achieving highly efficient heat conduction. Therefore, in practical applications, using a diamond thin film as the heat dissipation layer 3 allows for rapid heat transfer from the LED chips to the external environment, reducing the likelihood of efficiency degradation or device damage due to localized overheating of the sapphire substrate 1 during use.

[0041] Furthermore, in one embodiment of this application, a circuit layer 4 is also provided on the sapphire substrate 1. Specifically, the circuit layer 4 is formed on the reflective layer 2 of the first board surface 11 through steps such as evaporation, etching, and electroplating. The circuit layer 4 is divided into pixel areas. It should be noted that this division of pixel areas usually does not involve drawing actual dividing lines or using color lines on the circuit layer 4. A first pad 42 and a second pad 41 with opposite polarities are provided in the pixel area. The first pad 42 is a common electrode pad used to connect multiple chips or circuit modules in LED packaging. It is usually used as a physical connection point for grounding or common potential in the circuit. The second pad 41 is used to mount the RGB chip 7 in the subsequent LED chip manufacturing. The RGB chip 7 has positive and negative leads. When actually mounting the RGB chip 7, the positive and negative leads of the RGB chip 7 are respectively mounted on the second pad 41 and the first pad 42 according to the actual installation requirements to form a positive and negative circuit connection.

[0042] In one embodiment of this application, the length direction of the first pad 42 extends along the width direction of the sapphire substrate 1, and the number of second pads 41 corresponds to the number of RGB chips 7, with three second pads 41 spaced apart along the width direction of the sapphire substrate 1, and the first pad 42 and the three second pads 41 spaced apart along the length direction of the sapphire substrate 1. In another embodiment of this application, the length direction of the first pad 42 may also extend along the length direction of the sapphire substrate 1, and the three second pads 41 may be spaced apart from the first pad 42 along the width direction of the sapphire substrate 1, and the three second pads 41 may also be spaced apart along the length direction of the sapphire substrate 1.

[0043] In one embodiment of this application, three second pads 41 are specifically provided in a linear arrangement to accommodate a linear display scenario of a single row of RGB chips 7. In other embodiments of this application, the second pads 41 may also adopt a triangular arrangement. For full-color mixing requirements, the three second pads 41 are symmetrically distributed at 120° with a center spacing of 0.8-1.5mm, forming a uniform RGB light spot array.

[0044] Furthermore, to further optimize the area utilization of the sapphire substrate 1, the pixel region of the circuit layer 4 includes at least a first pixel region 44 and a second pixel region 45, and the first pixel region 44 and the second pixel region 45 share a first pad 42 or a second pad 41. For example, if a set of RGB chips 7 is provided on both the first pixel region 44 and the second pixel region 45, then the first pixel region 44 and the second pixel region 45 share the first pad 42; or, if a second pad 41 is provided on both the first pixel region 44 and the second pixel region 45, then the first pixel region 44 and the second pixel region 45 share the second pad 41.

[0045] Furthermore, in another embodiment of this application, referring to Figure 2 The pixel region can also be configured as a first pixel region 44, a second pixel region 45, and a third pixel region 46. Two of these three pixel regions share a first pad 42, and one of these two pixel regions shares a second pad 41 with the remaining pixel region among the three. For example, when the first pixel region 44 and the second pixel region 45 share the first pad 42, then the second pixel region 45 and the third pixel region 46 share the second pad 41. This reduces the number of wire connections, lowers the wiring density of the circuit layer, and can also adapt to complex spatial layout requirements.

[0046] Furthermore, during the soldering process, solder bridging may occur between adjacent second pads 41 or between the first pad 42 and the second pad 41 due to solder overflow or flow. Solder bridging can cause short circuits, signal crosstalk, and other problems, severely reducing product yield. The occurrence of solder bridging is usually closely related to solder material characteristics, process deviations, and thermodynamic effects. In addition, the interaction between surface tension and pad spacing is also a major contributing factor. According to thermodynamic formulas, when the ratio of surface tension to pad spacing exceeds the solid-liquid interface energy of the solder, bridging becomes unavoidable. Therefore, to reduce the possibility of solder bridging between adjacent second pads 41 or between the second pad 41 and the first pad 42, solder resist 43 is also provided between adjacent second pads 41 or between the second pad 41 and the first pad 42.

[0047] In one embodiment of this application, the solder resist 43 is specifically an ink sheet made of ink. The ink possesses excellent insulation, high-temperature resistance, processing flexibility, cost-effectiveness, and adjustable formulation, making it a preferred material for the solder resist 43 in most production situations. Specifically, the ink material uses epoxy resin as a matrix, supplemented with nanoscale fillers, such as silica or boron nitride, to enhance its heat resistance and mechanical strength. Simultaneously, curing agents, coupling agents, and other additives are added to optimize rheological properties and interfacial bonding.

[0048] Reference Figure 3This application also discloses an LED lamp bead, specifically including the aforementioned substrate, encapsulation layer 5, and protective layer 6. The encapsulation layer 5 is specifically disposed on the reflective layer 2 of the first surface 11 of the sapphire substrate 1. During the encapsulation process of the lamp bead, the RGB chip 7 is first placed in the second pad 41, and then the encapsulation layer 5 is disposed to encapsulate and protect the RGB chip 7. In one embodiment of this application, the encapsulation layer 5 is made of epoxy resin. Through its excellent optical transparency, temperature resistance, and low curing shrinkage, it effectively reduces the damage to the RGB chip 7 caused by oxygen, moisture, and mechanical stress, thereby protecting the RGB chip 7 from external oxidation. Furthermore, the encapsulation layer 5 contains diffusing powder to increase the light emission angle and improve luminous efficiency. Specifically, the diffusing powder is usually selected from inorganic microparticles with a refractive index between 1.6 and 2.0, such as silicon dioxide, barium sulfate, or aluminum oxide, with its particle size strictly controlled within the range of 0.5-5 μm, forming a controllable scattering effect on incident light to further improve luminous efficiency.

[0049] In practical use, the encapsulation layer 5, as a key structure protecting the LED chips from the external environment, is primarily made of epoxy resin. Over long-term use, its performance may deteriorate due to environmental factors such as moisture absorption and high-temperature oxidation. For example, moisture absorption-induced expansion and deformation weakens the bond between the encapsulation layer 5 and the sapphire substrate 1, while high-temperature accelerated oxidation causes the epoxy resin to yellow and its light transmittance to decrease, ultimately affecting the device's luminous efficiency and lifespan. Therefore, to reduce the impact of moisture absorption and high temperatures on the epoxy resin of the encapsulation layer 5, a protective layer 6 is also coated on its surface. The protective layer 6 can be a material containing silica. By adding epoxy resin for heat dissipation and slowing down its moisture absorption, the oxidation rate of the epoxy resin is slowed down, thus protecting the entire LED chip.

[0050] Furthermore, to ensure the integrity of the five sides of the encapsulation layer and to protect the colloid from external influences, a GOB (Glass On Board) process can be used in the subsequent LED chip encapsulation process to completely wrap the sides of the LED chips. This involves permeating transparent nanomaterials into the entire PCB board through the gaps between adjacent LED chips after the LED chips are mounted on the PCB, completely encapsulating the LED chips and further improving airtightness. After LED chip encapsulation, laser cutting can be performed. Laser cutting reduces the risk of breakage and unevenness in the pixel area of ​​the sapphire substrate.

[0051] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0052] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0053] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A substrate for manufacturing LED lamp beads, characterized in that, It includes: A sapphire substrate (1) has a first plate surface (11) and a second plate surface (12) arranged opposite to each other along the thickness direction of the sapphire substrate (1). A reflective layer (2) is disposed on the first plate surface (11); And a heat dissipation layer (3), which is disposed on the second plate surface (12).

2. The substrate for manufacturing LED beads according to claim 1, characterized in that: It also includes: A circuit layer (4) is disposed on the surface of the reflective layer (2) away from the first plate surface (11); The circuit layer (4) is divided into pixel areas, and the circuit layer (4) is provided with a first pad (42) and a second pad (41) for soldering to the pins of the RGB chip (7) corresponding to the pixel areas. The first pad (42) and the second pad (41) have opposite polarities.

3. The substrate for manufacturing LED beads according to claim 2, characterized in that: Within the pixel area, there is one first pad (42) and three second pads (41); The length of the first pad (42) extends along the first direction, and each of the second pads (41) is distributed along the first direction; The first pad (42) and the second pad (41) are spaced apart along the second direction; Wherein, the first direction is one of the length and width of the sapphire substrate (1), and the second direction is the other of the length and width of the sapphire substrate (1).

4. A substrate for manufacturing LED beads according to claim 2, characterized in that: The pixel region includes at least a first pixel region (44) and a second pixel region (45), wherein the first pixel region (44) and the second pixel region (45) share the first pad (42) or the second pad (41).

5. A substrate for manufacturing LED beads according to claim 2, characterized in that: The pixel region includes at least a first pixel region (44), a second pixel region (45), and a third pixel region (46). Two of the three pixel regions (44, 45, and 46) share the first pad (42), and one of the two pixel regions shares the second pad (41) with the remaining pixel region (44, 45, and 46).

6. A substrate for manufacturing LED beads according to claim 2, characterized in that: The circuit layer (4) is further provided with a solder mask (43), and the solder mask (43) is located between the first pad (42) and the second pad (41), or between the first pad (42) and the first pad (42).

7. A substrate for manufacturing LED beads according to claim 1, characterized in that: The heat dissipation layer (3) includes a diamond film.

8. An LED lamp bead, characterized in that, It includes: A substrate for manufacturing LED beads as described in any one of claims 1-7.

9. An LED lamp bead according to claim 8, characterized in that, It also includes: An encapsulation layer (5) is disposed on the reflective layer (2), and an RGB chip (7) is disposed inside the encapsulation layer (5). And a protective layer (6) disposed on the encapsulation layer (5).

10. An LED lamp bead according to claim 9, characterized in that: The encapsulation layer (5) is made of epoxy resin, and a diffusion powder is disposed inside the encapsulation layer (5).

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