Heat insulation layer preparation method for heat insulation of display module lamp drive, heat insulation PCB substrate and heat insulation COB module

Abstract

The invention discloses a preparation method of a heat insulation layer for heat insulation of a display module lamp drive, a heat insulation PCB substrate and a heat insulation COB module, and belongs to the technical field of display module heat insulation. Gamma-aminopropyltriethoxysilane is used as a coupling agent, fumed silica is subjected to ultrasonic dispersion treatment in an ethanol solution of the gamma-aminopropyltriethoxysilane, the pretreated fumed silica is mixed with a binder and an additive according to a certain proportion to form a heat insulation material, and then a heat insulation layer is formed on the surface of a base plate; the heat insulation PCB substrate and the heat insulation COB module are provided with the heat insulation layer; by optimizing the preparation process of the heat insulation layer and the combination mode of the heat insulation layer and the display module, high-precision installation and a good sealing effect of the heat insulation layer are achieved, and the heat insulation effect is further enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat insulation of display modules, and specifically relates to a method for preparing a heat insulation layer for heat isolation of a display module lamp drive, a heat insulation PCB substrate, and a heat insulation COB module. Background Art

[0002] COB display modules have been widely used in modern display technology. However, the lamp driver (light source and drive circuit) generates a lot of heat during operation. If this heat cannot be effectively isolated, it will have a serious impact on the performance and life of the display module. On the one hand, excessively high temperature may reduce the luminous efficiency of the light source and shift the color coordinates, affecting the display effect; on the other hand, it will also degrade the performance of electronic components in the drive circuit, reducing its reliability and service life. Traditional heat insulation methods often have problems such as poor heat insulation effect and poor compatibility with display modules. Therefore, there is an urgent need for an efficient heat isolation technology to solve the heat dissipation problem of COB display module lamp drivers. Summary of the invention

[0003] The present invention overcomes the shortcomings of the prior art, and proposes a heat insulation layer for heat isolation of a display module lamp driver and a preparation method thereof, a heat insulation PCB substrate, and a heat insulation COB module; and solves the heat dissipation problem of a COB display module lamp driver.

[0004] The present invention is achieved through the following technical solutions: A method for preparing a heat insulation layer for heat isolation of a display module lamp drive comprises the following steps: S1. Pretreatment: using γ-aminopropyltriethoxysilane as a coupling agent, adding the coupling agent to an ethanol solution of fumed silica for ultrasonic dispersion treatment, and then drying for standby use; in the thermal insulation material, the mass percentage of fumed silica is 50%-80%, the mass percentage of the binder is 10%-40%, and the mass percentage of the additive is ≤10%; the mass fraction of the ethanol solution of fumed silica is 5%-20%; S2, mixing: mixing the pretreated fumed silica with a binder and an additive in a certain proportion to form a thermal insulation material; the mixing is carried out by combining high-speed stirring and ultrasonic dispersion; S3, forming the heat insulation material into a heat insulation layer on the surface of the substrate.

[0005] Preferably, the speed of the high-speed stirring is 1000-3000 rpm, and the stirring time is 15-60 minutes; the power of the ultrasonic dispersion is 200-1000W, and the ultrasonic time is 10-30 minutes.

[0006] Preferably, the forming is carried out by coating, pressing or 3D printing.

[0007] Preferably, the coating method is to evenly coat the thermal insulation material on the surface of the substrate with a coating thickness of 50-500μm; the pressing method is to put the thermal insulation material into a mold and press it into shape at a pressure of 5-50Mpa; 3D printing is used for thermal insulation layers that require a three-dimensional structure.

[0008] A heat-insulating PCB substrate comprises a copper foil laid on the heat-insulating layer; the heat-insulating layer and the copper foil are closely attached to each other by heat pressing.

[0009] Preferably, multiple layers of the heat-insulating PCB substrates are stacked layer by layer and hot-pressed into shape.

[0010] More preferably, the temperature of the hot pressing molding is 150-200° C., the pressure is 10-30 MPa, and the time is 30-90 minutes.

[0011] Preferably, drilling and etching are performed on the multi-layer PCB substrate formed after hot pressing.

[0012] A heat-insulating COB module mounts an LED chip on the heat-insulating PCB substrate, then solders the lamp surface by reflow soldering, and then mounts the drive surface and packages the lamp surface with a film.

[0013] Preferably, the heat-insulating PCB substrate is cleaned and surface-treated before mounting the LED chip.

[0014] The beneficial effects of the present invention compared with the prior art are as follows: 1. The present invention utilizes the excellent thermal insulation performance of fumed silica to effectively isolate the heat generated by the lamp driver, significantly improves the heat dissipation performance of the COB display module, and reduces the impact of heat on the display effect and component life.

[0015] 2. The present invention achieves high-precision installation and good sealing effect of the thermal insulation layer by optimizing the preparation process of the thermal insulation layer and the combination method with the display module, thereby further enhancing the heat isolation effect.

[0016] 3. The heat insulation technology of the present invention has good adaptability and can be applied to COB display modules of different sizes and powers, providing an efficient and reliable solution for the thermal management of COB display modules.

[0017] 4. The low thermal conductivity of fumed silica (specific thermal conductivity range, such as 0.01 - 0.03W / (m·K)) and its porous structure can greatly hinder the conduction of heat in the insulation layer. When heat is transferred to the insulation layer, the heat conduction path is greatly extended due to the pores between the fumed silica particles and the low thermal conductivity air filling them, thereby reducing the heat conduction efficiency.

[0018] 5. Since fumed silica has the characteristics of small particle size, uniform particle size distribution, large specific surface area, etc., its primary particle size is at the nanometer level, and it has a developed pore structure, which can form a large number of three-dimensional structures in a certain volume space to prevent heat conduction, making it an ideal choice. In addition, its thermal expansion coefficient is low, and the difference with the thermal expansion coefficient of PCB substrate materials is small. It is not easy to generate stress concentration during the thermal cycle process, thereby reducing the damage to the PCB substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a cross-sectional view of a PCB board with a fumed silica thermal insulation layer as described in the embodiment; Figure 2 This is a schematic diagram of heat conduction of an existing PCB board; Figure 3 Schematic diagram of heat conduction of a PCB board with a fumed silica thermal insulation layer as described in the embodiment. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail in conjunction with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The technical solutions of the present invention are described in detail below in conjunction with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.

[0021] Example 1 This embodiment provides a method for preparing a heat insulation layer for heat isolation of a display module lamp drive, which specifically comprises the following steps: S1. Preprocessing Pre-treat the fumed silica: Use a silane coupling agent to modify its surface. Some groups in the silane coupling agent molecules can react with the hydroxyl groups on the surface of the fumed silica, while other groups can interact with the binder or other organic materials, thereby improving the dispersibility of the fumed silica in the system and the binding force with the binder.

[0022] In this embodiment, γ-aminopropyltriethoxysilane is used as a coupling agent, and fumed silica is subjected to ultrasonic dispersion treatment in its ethanol solution for a period of time, and then dried for use.

[0023] Specifically, solution preparation: Slowly add a certain amount of fumed silica to an appropriate amount of ethanol to form a fumed silica ethanol solution with a concentration of 15% (mass fraction). During the addition process, use a magnetic stirrer to slowly stir to evenly disperse the fumed silica in the ethanol to avoid the formation of agglomerates.

[0024] Accurately weigh γ-aminopropyltriethoxysilane in a ratio of 3% (the optional range is 1%-5%) of the mass of fumed silica, and slowly drop it into the above solution. Continue stirring for a while to allow the coupling agent to be fully mixed in the solution.

[0025] Ultrasonic dispersion: The prepared fumed silica ethanol solution containing a coupling agent is placed in an ultrasonic device for ultrasonic treatment. The ultrasonic time is generally 15min-60min, and the ultrasonic time in this embodiment is 30min; the ultrasonic power and frequency can be appropriately adjusted according to the specific equipment and solution volume. During the ultrasonic process, tiny bubbles in the solution will continue to be generated and burst, forming strong shock waves and microjets, breaking up the agglomerates on the surface of the fumed silica particles, and promoting the reaction of the coupling agent with the hydroxyl groups on the surface of the fumed silica to achieve uniform dispersion and good coupling effect.

[0026] S2, Mixed The pretreated fumed silica, binder and additive are mixed in a certain proportion. The mixture is treated by a combination of high-speed stirring and ultrasonic dispersion to ensure that the components are evenly mixed. During the high-speed stirring process, the rotation speed is 2000 rpm and the stirring time is 30 minutes. The ultrasonic dispersion power can be selected according to the volume of the mixed system. In this embodiment, it is 600W and the ultrasonic time is 20 minutes. This can effectively break the agglomerates of fumed silica and make it evenly dispersed in the binder.

[0027] In this embodiment, the binder is epoxy resin and the additive is glass fiber; wherein the mass percentage of fumed silica is 65%, the mass percentage of the binder is 30%, and the mass percentage of the additive is 5%; Specifically, the choice of binder is crucial; common binders include organic binders such as epoxy resin, phenolic resin, etc. and inorganic binders such as sodium silicate, water glass, etc. Organic binders have good flexibility and bonding properties, which can enable the thermal insulation material to maintain good shape stability after molding; inorganic binders have the advantages of high temperature resistance and aging resistance. For example, when epoxy resin is used as a binder, the cured material has high strength and can well bond the fumed silica particles together.

[0028] Additives: Additives can be selected according to the specific performance requirements of the thermal insulation material. For example, in order to improve the flame retardancy of the thermal insulation material, flame retardants such as aluminum hydroxide and magnesium hydroxide can be added; in order to improve the UV resistance of the material, ultraviolet absorbers can be added; in order to enhance the mechanical properties of the material, fiber additives such as glass fiber and carbon fiber can be added.

[0029] S3, Forming According to the design requirements of the PCB substrate, the mixed material is formed into an insulation layer. If a flat insulation layer is to be prepared, coating or pressing methods can be used. The coating method can evenly coat the mixed material on the surface of the substrate by screen printing, scraper coating, etc. The coating thickness is determined according to the insulation requirements, generally between 50-500μm. The pressing method is to put the mixed material into a mold and press it under a certain pressure and temperature (the pressure is usually 5-50MPa, and the temperature is determined according to the curing requirements of the binder). For insulation layers that require a three-dimensional structure, advanced technologies such as 3D printing can be used to print the material according to the designed three-dimensional model.

[0030] Example 2 This embodiment provides a heat-insulating PCB substrate, and the assembly method of the heat-insulating PCB substrate is as follows: S1. Copper foil laying Copper foil is laid on the fumed silica insulation layer prepared in Example 1. The thickness of the copper foil can be selected according to the conductivity requirements of the PCB substrate, and common ones are 18μm, 35μm, 70μm, etc. This embodiment uses a 35μm PCB substrate. When laying the copper foil, ensure that it is closely attached to the surface of the insulation layer, and improve the bonding strength between the two by means of hot pressing or the like.

[0031] S2. Multilayer structure assembly For multi-layer PCB substrates, repeat the above steps to stack the substrates with insulation layers and copper foils layer by layer. During the stacking process, attention should be paid to the alignment accuracy between the layers, and positioning can be performed by using positioning holes and other methods. Each stacked layer needs to be properly hot-pressed to ensure good bonding between the layers. The hot-pressing temperature, pressure and time need to be optimized according to the properties of the material and the number of layers of the substrate. For example, for a four-layer PCB substrate, the hot-pressing temperature is 200°C, the pressure is 30MPa, and the time is 60 minutes.

[0032] S3, drilling, etching and other subsequent processing After the multi-layer structure is assembled, subsequent processing such as drilling and etching is carried out according to the design requirements of the PCB substrate. During the drilling process, attention should be paid to controlling the accuracy and quality of the drilling to avoid damage to the thermal insulation layer. The etching process removes unnecessary copper foil according to the designed circuit pattern to form a conductive circuit. The choice of etching solution and etching time should be adjusted according to the thickness and quality of the copper foil to ensure the accuracy and consistency of the etching effect.

[0033] Example 3 This embodiment provides a heat-insulating COB module, and the assembly method is as follows: S1. LED chip mounting The heat-insulating PCB substrate prepared in Example 2 is cleaned and surface treated to ensure its surface flatness and cleanliness. After printing, the LED chip is mounted on the substrate using a high-precision mounter, and then the lamp surface is soldered by reflow soldering. S2, drive surface mounting Perform driver IC mounting and welding on the board after die bonding. Pay attention to using the furnace fixture for reflow soldering during welding. S3, lamp surface film packaging and cutting After the board with the driven surface welded is treated with film, it is subjected to film pasting.

[0034] See also Figure 1 In the manufacturing process of PCB boards, the prepared silicon dioxide insulation layer is sandwiched between the middle layer of the PCB board, and then the layers of materials are pressed together by heat pressing and other methods. During the pressing process, parameters such as temperature, pressure and time need to be controlled to ensure that the silicon dioxide insulation layer can be tightly combined with other layers of the PCB board and will not affect the thermal insulation performance of silicon dioxide.

[0035] See also Figure 2 and Figure 3 The low thermal conductivity of fumed silica (specific thermal conductivity range, such as 0.01-0.03W / (m·K)) and its porous structure can greatly hinder the conduction of heat in the thermal insulation layer. When heat is transferred to the thermal insulation layer, the heat conduction path is greatly extended due to the pores between the fumed silica particles and the low thermal conductivity air filling them, thereby reducing the heat conduction efficiency.

[0036] The fumed silica thermal insulation layer has the characteristics of small particle size, uniform particle size distribution, and large specific surface area. Its primary particle size is at the nanometer level, and it has a developed pore structure. It can form a large number of three-dimensional structures in a certain volume space to prevent heat conduction, making it an ideal choice. In addition, its thermal expansion coefficient is low, and the difference with the thermal expansion coefficient of the PCB substrate material is small. It is not easy to generate stress concentration during the thermal cycle, thereby reducing the damage to the PCB substrate.

[0037] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be determined that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the present invention, which should be regarded as belonging to the present invention and the scope of patent protection determined by the submitted claims.

Claims

1. A method for preparing a heat insulation layer for heat isolation of a display module lamp drive, characterized in that: The following steps are involved: S1. Pretreatment: using γ-aminopropyltriethoxysilane as a coupling agent, adding the coupling agent to an ethanol solution of fumed silica for ultrasonic dispersion treatment, and then drying for standby use; the mass fraction of the ethanol solution of fumed silica is 5%-20%; S2, mixing: the pretreated fumed silica is mixed with a binder and an additive in a certain proportion to form a thermal insulation material; the mixing is carried out by a method combining high-speed stirring and ultrasonic dispersion; in the thermal insulation material, the mass percentage of fumed silica is 50%-80%, the mass percentage of the binder is 10%-40%, and the mass percentage of the additive is ≤10%; S3, forming the heat insulation material into a heat insulation layer on the surface of the substrate.

2. A method for preparing a heat insulation layer for heat isolation of a display module lamp drive according to claim 1, characterized in that: The rotation speed of the high-speed stirring is 1000-3000 rpm, and the stirring time is 15-60 minutes; the power of the ultrasonic dispersion is 200-1000W, and the ultrasonic time is 10-30 minutes.

3. The method for preparing a heat insulation layer for heat isolation of a display module lamp drive according to claim 1, characterized in that: The forming is carried out by coating, pressing or 3D printing.

4. A method for preparing a heat insulation layer for heat isolation of a display module lamp drive according to claim 3, characterized in that: The coating method is to evenly coat the thermal insulation material on the surface of the substrate with a coating thickness of 50-500μm; the pressing method is to put the thermal insulation material into a mold and press it into shape under a pressure of 5-50Mpa; 3D printing is used for thermal insulation layers that require a three-dimensional structure.

5. A heat-insulating PCB substrate, characterized in that: Copper foil is laid on the heat insulation layer as described in any one of claims 1 to 4; and the heat insulation layer and the copper foil are closely attached to each other by hot pressing.

6. The heat-insulating PCB substrate according to claim 5, characterized in that: The multiple layers of the heat-insulating PCB substrate are stacked layer by layer and hot-pressed into shape.

7. The heat-insulating PCB substrate according to claim 6, characterized in that: The temperature of the hot pressing molding is 150-200° C., the pressure is 10-30 MPa, and the time is 30-90 minutes.

8. The heat-insulating PCB substrate according to claim 6, characterized in that: Drilling and etching are performed on the multi-layer PCB substrate formed after thermoforming.

9. A heat-insulating COB module, characterized in that: The LED chip is mounted on the heat-insulating PCB substrate as claimed in claim 5, and then the lamp surface is soldered by reflow soldering, and then the drive surface is mounted and the lamp surface is film-sealed.

10. The heat-insulating COB module according to claim 9, characterized in that: The heat-insulating PCB substrate is cleaned and surface-treated before mounting the LED chip.

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