Micro-LED display module with improved thermal management and preparation method thereof

Abstract

The invention discloses a Micro-LED display module with improved thermal management, and the module comprises a supporting substrate which is provided with a first surface and a second surface which are opposite to each other; the enclosure bulkhead is arranged on the first surface of the supporting substrate, and an accommodating space is defined by the enclosure bulkhead; the Micro-LED light-emitting module is fixed to the first surface of the supporting substrate through a bonding metal layer and arranged in the containing space defined by the surrounding wall. The heat management structure is arranged on the second surface of the supporting substrate; wherein the Micro-LED light-emitting module is in thermal connection with the surrounding wall. The Micro-LED light-emitting module is arranged in the containing space defined by the surrounding wall, and the Micro-LED light-emitting module is in thermal connection with the surrounding wall, so that a transverse additional heat dissipation channel is formed, heat of the Micro-LED light-emitting module is guided to be diffused to the periphery through the surrounding wall, heat accumulation of a vertical heat dissipation path is effectively relieved, and a heat transfer path is shortened. And meanwhile, a heat management structure is arranged, so that efficient export of a vertical heat dissipation path is guaranteed. Through the synergistic effect of transverse and vertical heat dissipation paths, the overall heat dissipation efficiency and the temperature field uniformity are improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a micro-LED display module with improved thermal management and its fabrication method. Background Technology

[0002] Micro-LED, as a next-generation display technology, possesses excellent characteristics such as high brightness, high contrast, fast response speed, and long lifespan. However, as pixel size shrinks to the micrometer level and is highly integrated on the driving substrate, the heat flux density per unit area increases significantly. Under conditions of high brightness, high duty cycle, or high current driving, Micro-LED chips are prone to problems such as increased junction temperature, decreased luminous efficiency, wavelength drift, and reduced reliability.

[0003] Current thermal management of Micro-LED display modules primarily relies on a vertical heat dissipation path: heat generated in the active area of ​​the chip passes sequentially through the driving substrate, adhesive layer, and module support structure, ultimately dissipating to the external environment via convection and heat exchange. If any link in this path has a heat dissipation bottleneck, such as high interface thermal resistance, insufficient thermal conductivity of the support structure, or limited heat dissipation surface area, heat will be difficult to dissipate and dissipate in a timely manner, easily forming hot spots in localized areas, severely affecting the temperature uniformity and long-term stability of the Micro-LED display module.

[0004] Existing heat dissipation technologies for Micro-LEDs mostly rely on adding heat dissipation components to the outside of the module, and each solution has its own problems: passive heat dissipation solutions (such as large-volume fins) have simple structures but limited heat dissipation capacity and are prone to causing module volume expansion and reduced compatibility with packaging processes; active heat dissipation technologies (such as microchannel liquid cooling and forced air cooling) can improve heat dissipation efficiency, but often have problems such as increased system volume, increased structural complexity, or increased reliability risks; thermoelectric coolers, as an active temperature control method, are highly dependent on the quality of the heat dissipation path at the hot end. If the heat dissipation capacity at the hot end is insufficient, the heat transported to the hot end by the thermoelectric cooler and its own Joule heat cannot be dissipated in time, and the active cooling effect will be limited. Summary of the Invention

[0005] This invention aims to provide a Micro-LED display module with improved thermal management and its fabrication method. By increasing the lateral heat dissipation path, the lateral heat diffusion efficiency and overall heat dissipation performance are improved, significantly improving the temperature uniformity of the Micro-LED display module, suppressing the formation of local hot spots, and effectively reducing the operating junction temperature. This alleviates the decay of luminous efficiency and wavelength drift, and ensures the stability and long-term reliability of the optical performance of the device under high brightness, high duty cycle or high current driving conditions.

[0006] In a first aspect, the present invention provides a Micro-LED display module with improved thermal management, comprising: A support substrate having a first surface and a second surface facing away from each other; A wall is provided on the first surface of the supporting substrate and encloses a receiving space; The Micro-LED light-emitting module is fixed to the first surface of the supporting substrate by an adhesive metal layer and placed in the receiving space formed by the enclosure wall; A thermal management structure is disposed on the second surface of the supporting substrate; The Micro-LED light-emitting module is thermally connected to the enclosure wall.

[0007] The improved thermal management Micro-LED display module provided by this invention places the Micro-LED light-emitting module within an enclosed space formed by a surrounding wall, and thermally connects the Micro-LED light-emitting module and the surrounding wall to form an additional lateral heat dissipation path. This guides the heat from the Micro-LED light-emitting module to diffuse to the surrounding area through the surrounding wall, effectively alleviating heat accumulation along the vertical heat dissipation path and shortening the heat transfer path. Simultaneously, a thermal management structure is provided on the second surface of the supporting substrate to ensure efficient heat dissipation along the vertical heat dissipation path. Through the synergistic effect of the lateral and vertical heat dissipation paths, the overall heat dissipation efficiency and temperature field uniformity are improved, suppressing the formation of local hot spots. This alleviates the luminous efficiency decay and wavelength drift caused by increased junction temperature, thereby improving the optical performance stability and long-term operational reliability of the Micro-LED display module under high brightness, high duty cycle, or high current driving conditions.

[0008] As an optional solution for the Micro-LED display module of the present invention, the way the Micro-LED light-emitting module is thermally connected to the enclosure is: the Micro-LED light-emitting module is in direct contact with the enclosure; or, a filling gap is formed between the Micro-LED light-emitting module and the enclosure, and a heat-conducting medium is provided in the filling gap.

[0009] As a preferred embodiment of the above-mentioned optional solutions, the thermally conductive medium is at least one of thermally conductive silver paste, thermally conductive gel, thermally conductive silicone grease or phase change thermally conductive material, and the width of the filling gap is 10μm to 200μm.

[0010] As an optional embodiment of the Micro-LED display module of the present invention, the thermal conductivity of the material used to make the supporting substrate and the surrounding wall is not less than 20 W / (m·K).

[0011] As an optional embodiment of the Micro-LED display module of the present invention, the materials of the supporting substrate and the surrounding wall are selected from at least one of aluminum nitride ceramic, alumina ceramic, diamond, aluminum nitride / resin composite material, boron nitride / resin composite material and alumina / resin composite material; the supporting substrate and the surrounding wall are integrally formed from the same material.

[0012] As an optional embodiment of the Micro-LED display module of the present invention, the height of the enclosure is 5μm to 50μm greater than the sum of the thickness of the Micro-LED light-emitting module and the adhesive metal layer; a first surface microstructure is provided on the outer side of the enclosure.

[0013] As a preferred embodiment of the above-mentioned optional solutions, the microstructure of the first surface is at least one of the following: a groove array, a bump array, a through-hole structure, an inner concave hemispherical array, and an outer convex hemispherical array.

[0014] As an optional embodiment of the Micro-LED display module of the present invention, the Micro-LED display module further includes a transparent encapsulation layer and a printed circuit board; the enclosure is formed by three side walls to create a U-shaped groove with an open end, the printed circuit board is located on the outside of the open end, and the transparent encapsulation layer covers the top of the U-shaped groove, together with the enclosure to form a closed cavity; the transparent encapsulation layer is a cover glass, a filter, or a stacked structure of cover glass and filter; the printed circuit board is an FR4 printed circuit board, which has printed circuits and pads, and the pads are electrically connected to the Micro-LED light-emitting module through gold wires.

[0015] As an optional embodiment of the Micro-LED display module of the present invention, the bonding metal layer is made of die-bonding silver paste or gold-tin alloy, and the thickness of the bonding metal layer is 5μm to 50μm; the thermal management structure is at least one of surface microstructure, thermally conductive diffusion structure, and thermoelectric cooler.

[0016] As a preferred embodiment of the above-mentioned optional solutions, the surface microstructure is at least one of the following: groove array, bump array, through-hole structure, concave hemispherical array, and convex hemispherical array.

[0017] As a preferred embodiment of the above-mentioned optional solutions, the heat-conducting diffusion structure comprises, in sequence: an adhesive layer disposed on the second surface of the supporting substrate, high thermal conductivity rods, and a substrate; gaps are maintained between the high thermal conductivity rods to form heat dissipation channels.

[0018] As another preferred embodiment of the above-mentioned optional solutions, the thermoelectric cooler sequentially includes: a first conductive circuit layer, a first electrical connection layer, a P / N semiconductor heat dissipation module, a second electrical connection layer, a second conductive circuit layer, a thermally conductive substrate, and a power supply interface disposed on the second surface of the supporting substrate; the second conductive circuit layer is electrically connected to the power supply interface; the P / N semiconductor heat dissipation module includes an array of thermoelectric units, which are electrically connected in series and thermally connected in parallel through the first conductive circuit layer and the second conductive circuit layer to form a thermoelectric cooling circuit; thermally conductive insulating encapsulation material is filled between the thermoelectric units and around the P / N semiconductor heat dissipation module.

[0019] As an alternative to the above preferred embodiment, the first electrical connection layer and the second electrical connection layer are at least one of solder layer, sintered metal layer, transient liquid phase diffusion connection layer or conductive connection layer; the thermally conductive insulating encapsulation material is thermally conductive insulating potting compound or thermally conductive insulating composite encapsulation material; the side of the thermally conductive substrate away from the P / N semiconductor heat dissipation module is provided with at least one of surface microstructure, heat spreader, heat sink, metal shell or thermally conductive diffusion plate.

[0020] As an alternative to the above preferred solution, the Micro-LED display module also includes a control unit, which is electrically connected to the power supply interface of the thermoelectric cooler and configured to adjust the current magnitude and direction of the thermoelectric heat dissipation circuit according to the temperature signal of the Micro-LED light-emitting module.

[0021] Secondly, the present invention also provides a method for preparing the above-mentioned thermally improved Micro-LED display module, comprising the following steps: S1. Provide a support substrate and perform planarization, cleaning, and surface activation treatment on the support substrate; S2. A surrounding wall is provided on the first surface of the support substrate. The surrounding wall is formed by three side walls to form a U-shaped groove with an open end. The printed circuit board is fixed on the open end side. S3. Place the Micro-LED light-emitting module in the U-shaped groove and fix it to the first surface of the supporting substrate by bonding the metal layer; electrically connect the Micro-LED light-emitting module to the printed circuit board through gold wire; the Micro-LED light-emitting module is in direct contact with the enclosure wall, or the Micro-LED light-emitting module is thermally connected to the enclosure wall through a heat-conducting medium. S4. Prepare a thermal management structure on the second surface of the supporting substrate.

[0022] The invention provides a method for fabricating a micro-LED display module with improved thermal management. It defines core steps such as supporting substrate processing, enclosure setting, light-emitting module installation and thermal connection formation, and thermal management structure fabrication. It establishes a complete fabrication path that matches the structure of the micro-LED display module, enabling the thermal connection path and thermal management structure to be effectively realized in the manufacturing stage. This helps to ensure that the resulting micro-LED display module has stable thermal management performance and is feasible for mass production.

[0023] As an optional embodiment of the preparation method of the present invention, the preparation method further includes: S5. Cover the top surface of the U-shaped groove with a transparent encapsulation layer and fix it to the top surface of the enclosure wall with an adhesive to seal the enclosed space; S6. Prepare the first surface microstructure on the outer side of the enclosure; S7. Curing, testing, trimming, cleaning, and performance calibration of the prepared Micro-LED display module.

[0024] Additional aspects and advantages of the invention will be set forth in part in the description which follows, some of which will become clear as the description proceeds, and others will be learned by practicing the invention. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure of the Micro-LED display module in Embodiment 1 of this application.

[0027] Figure 2 This is a cross-sectional view of the Micro-LED display module in Embodiment 1 of this application.

[0028] Figure 3 This is a schematic diagram of the Micro-LED light-emitting module installation area in Embodiment 1 of this application.

[0029] Figure 4 This is a schematic diagram of the structure of the first conductive circuit layer in Embodiment 1 of this application.

[0030] Figure 5 This is a schematic diagram of the structure of the second conductive circuit layer in Embodiment 1 of this application.

[0031] Figure 6 This is a schematic diagram of the thermoelectric unit layout in Embodiment 1 of this application.

[0032] Figure 7 This is a schematic diagram of the structure after the thermoelectric unit is connected in Embodiment 1 of this application.

[0033] Figure 8 This is a schematic diagram of the structure of the P / N semiconductor heat dissipation module after insulation packaging in Embodiment 1 of this application.

[0034] Figure 9 This is a schematic diagram of the assembled Micro-LED light-emitting module in Embodiment 1 of this application.

[0035] Figure 10 This is a schematic diagram of the overall structure of the Micro-LED display module in Embodiment 2 of this application.

[0036] Figure 11 for Figure 10 A partially enlarged schematic diagram of the Micro-LED display module shown.

[0037] Figure 12 for Figure 10 The diagram shows a cross-sectional view of the Micro-LED display module.

[0038] Figure 13 This is a schematic diagram of the overall structure of the Micro-LED display module in Embodiment 3 of this application.

[0039] Figure 14 for Figure 13 A partially enlarged schematic diagram of the Micro-LED display module shown.

[0040] Figure 15 for Figure 13 The diagram shows a cross-sectional view of the Micro-LED display module.

[0041] In the figure: 1-Transparent encapsulation layer, 2-Supporting substrate, 3-P / N semiconductor heat dissipation module, 4-Thermal conductive substrate, 5-Thermal conductive medium, 6-Micro-LED light-emitting module, 7-Printed circuit board, 8-Adhesive metal layer, 9-Substrate, 10-Enclosure, 11-Surface microstructure, 12-Adhesive layer, 13-High thermal conductivity rod; 21-First surface, 22-Second surface, 221-First conductive circuit layer; 31-Thermoelectric unit, 311-P-type thermoelectric unit, 312-N-type thermoelectric unit, 32-Thermoelectric insulating encapsulation material; 41-Second conductive circuit layer; 42-Power supply interface; 71-Printed circuit board, 72-Pads; 101-U-shaped groove. Detailed Implementation

[0042] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0043] Current thermal management technology for Micro-LED display modules heavily relies on vertical unidirectional heat dissipation paths, lacking effective lateral heat diffusion mechanisms. This results in heat in high-density pixel arrays being confined within narrow vertical channels, unable to effectively dissipate to surrounding low-temperature areas, thus causing localized hotspots. The root cause of this deficiency lies in the fact that existing Micro-LED display modules typically employ a packaging configuration where self-emissive units, bonding layers, driving substrates, and support structures are stacked along the thickness direction. Their primary heat conduction channels naturally exhibit a top-to-bottom vertical heat transfer path. Simultaneously, constrained by device miniaturization, high-density integration, and packaging space limitations, existing structures often lack lateral heat-conducting components that are directly or efficiently thermally coupled to the heat-generating areas. Furthermore, the interfacial thermal resistance introduced by adhesive layers, packaging layers, and interfaces between different materials further weakens the lateral heat spread capability, resulting in limited heat diffusion area and difficulty in timely diverting localized heat to surrounding low-temperature areas. Additionally, traditional thermal design primarily focuses on enhancing heat dissipation along vertical paths, failing to proactively construct collaborative lateral heat conduction paths within the structure of Micro-LED display modules. As a result, the continuous accumulation of heat in localized areas not only exacerbates the increase in junction temperature, the decay of luminous efficiency, and wavelength drift, but also seriously damages the temperature uniformity and long-term operational reliability of the device, becoming a key bottleneck restricting the practical development of Micro-LEDs in applications such as high brightness, high duty cycle, or high current driving.

[0044] To address the above problems, embodiments of this application provide a Micro-LED display module with improved thermal management, comprising: The support substrate 2 has a first surface 21 and a second surface 22 facing away from each other; Enclosure 10 is disposed on the first surface 21 of the supporting substrate 2 and encloses to form an accommodating space 101; The Micro-LED light-emitting module 6 is fixed to the first surface 21 of the support substrate 2 by the adhesive metal layer 8 and placed in the receiving space 101 formed by the enclosure wall 10. A thermal management structure is disposed on the second surface 22 of the support substrate 2; it should be noted that the thermal management structure can ensure the efficient output of the vertical heat dissipation path; The Micro-LED light-emitting module 6 is thermally connected to the enclosure wall 10. It should be noted that this thermal connection allows the heat from the Micro-LED light-emitting module to diffuse to the surrounding area through the enclosure wall, forming an additional lateral heat dissipation path. This effectively alleviates heat accumulation along the vertical heat dissipation path and shortens the heat transfer path. Through the synergistic effect of the lateral and vertical heat dissipation paths, the overall heat dissipation efficiency and temperature field uniformity are improved.

[0045] In some embodiments, the Micro-LED light-emitting module 6 is thermally connected to the enclosure 10 in the following ways: the Micro-LED light-emitting module 6 is in direct contact with the enclosure 10; or, a filling gap is formed between the Micro-LED light-emitting module 6 and the enclosure 10, and a thermally conductive medium 5 is provided in the filling gap. It should be noted that both of the above implementation methods can achieve thermal connection, and the thermal connection method can be flexibly selected according to the device assembly tolerance, surface flatness, and process conditions, thereby improving process adaptability and assembly fault tolerance while ensuring thermal coupling effect.

[0046] In some embodiments, the thermally conductive medium 5 is at least one of thermally conductive silver paste, thermally conductive gel, thermally conductive silicone grease, or phase change thermally conductive material, and the width of the gap is 10 μm to 200 μm. It should be noted that the above-mentioned thermally conductive medium materials all have good interfacial gap-filling and thermal conductivity capabilities, which can reduce the interfacial thermal resistance between the Micro-LED light-emitting module and the enclosure; and the gap width range of 10 μm to 200 μm is beneficial to balance the feasibility of filling, interfacial adhesion, and thermal conduction efficiency, thereby further enhancing the auxiliary thermal conduction effect of the enclosure.

[0047] In some embodiments, the thermal conductivity of the materials used to fabricate the support substrate 2 and the enclosure 10 is not less than 20 W / (m·K). It should be noted that selecting materials within the above-mentioned thermal conductivity range ensures that the support substrate and the enclosure have sufficient heat diffusion and heat transfer capabilities, enabling the heat from the Micro-LED light-emitting module to be efficiently conducted to the external thermal management structure, reducing heat accumulation in the light-emitting area, and thus improving the thermal stability of the device.

[0048] In some embodiments, the materials of the support substrate 2 and the enclosure 10 are selected from at least one of aluminum nitride ceramic, alumina ceramic, diamond, aluminum nitride / resin composite material, boron nitride / resin composite material, and alumina / resin composite material; the support substrate 2 and the enclosure 10 are integrally formed from the same material. It should be noted that the above materials have high thermal conductivity, good mechanical strength, and certain electrical insulation, which is beneficial for balancing support and heat dissipation functions. Furthermore, integral forming helps reduce the interface and contact thermal resistance between the substrate and the enclosure, avoiding the risk of thermal mismatch, warping, or cracking caused by splicing dissimilar materials, thereby improving the overall structural stability and thermal management consistency.

[0049] In some embodiments, the height of the enclosure 10 is 5μm to 50μm greater than the sum of the thicknesses of the Micro-LED light-emitting module 6 and the bonding metal layer 8; a first surface microstructure is provided on the outer surface of the enclosure 10. It should be noted that the height of the enclosure is slightly greater than the total thickness of the light-emitting module, which can ensure packaging space and thermal contact conditions while avoiding interference. The microstructure on the outer surface of the enclosure can increase the heat dissipation surface area of ​​the lateral heat dissipation path and enhance the heat exchange capacity with the external medium, thereby further improving the auxiliary heat dissipation effect of the enclosure.

[0050] In some embodiments, the first surface microstructure is at least one of a groove array, a bump array, a through-hole structure, an inner concave hemispherical array, and an outer convex hemispherical array. It should be noted that different types of concave / convex or through-hole microstructures can increase the heat transfer area, change the airflow or heat flow distribution, and provide diverse structural options for subsequent process selection, thereby helping to optimize the heat dissipation performance of the outer surface of the enclosure according to different heat dissipation requirements.

[0051] In some embodiments, the Micro-LED display module further includes a transparent encapsulation layer 1 and a printed circuit board 7; the enclosure 10 is formed by three side walls to create a U-shaped groove 101 with an open end, the printed circuit board 7 is disposed on the outside of the open end, and the transparent encapsulation layer 1 covers the top of the U-shaped groove 101, together with the enclosure 10 to form a closed cavity; the transparent encapsulation layer 1 is a cover glass, a filter, or a stacked structure of cover glass and filter; the printed circuit board 7 is an FR4 printed circuit board, and the printed circuit board 7 is provided with printed circuits 71 and pads 72, the pads 72 being electrically connected to the Micro-LED light-emitting module 6 via gold wires. It should be noted that placing the printed circuit board at the open end of the U-shaped groove facilitates electrical connection with the Micro-LED light-emitting module, and also facilitates modular and miniaturized packaging; in addition, the closed cavity formed by the transparent encapsulation layer provides a relatively enclosed and protected working space for the Micro-LED light-emitting module, reducing the impact of external pollution and mechanical damage, while the transparent encapsulation layer does not affect light emission, thus balancing optical function and structural protection.

[0052] In some embodiments, the bonding metal layer 8 is made of die-bonding silver paste or gold-tin alloy, and the thickness of the bonding metal layer 8 is 5μm to 50μm; the thermal management structure is at least one of surface microstructure 11, thermally conductive diffusion structure, and thermoelectric cooler. It should be noted that die-bonding silver paste or gold-tin alloy is beneficial for balancing chip fixation strength and thermal conductivity, and an appropriate thickness range is beneficial for reducing interface thermal resistance and ensuring connection reliability; at the same time, limiting the thermal management structure to surface microstructure or thermoelectric cooler makes it easier to select passive heat dissipation or active cooling schemes according to different application scenarios, improving the flexibility of thermal management design.

[0053] In some embodiments, the surface microstructure 11 is at least one of a groove array, a bump array, a through-hole structure, an inner concave hemispherical array, and an outer convex hemispherical array. It should be noted that the above microstructures can all increase the heat exchange area and improve the surface heat exchange efficiency, thereby enhancing the passive heat dissipation capability of the second surface of the supporting substrate, and are particularly suitable for scenarios where active cooling is not used or where heat dissipation needs to be coordinated with active cooling.

[0054] In some embodiments, the heat-conducting diffusion structure sequentially includes: an adhesive layer 12 disposed on the second surface 22 of the support substrate 2, a high thermal conductivity rod 13, and a substrate 9. It should be noted that after the heat from the Micro-LED light-emitting module is longitudinally conducted to the support substrate, it can be further coupled to the high thermal conductivity rod via the adhesive layer, and rapidly diffuse along the high thermal conductivity rod to areas away from the local heat source, before being released to the outside from the substrate. Simultaneously, the heat dissipation channels formed between the high thermal conductivity rods facilitate natural air convection, and surface microstructures can be further provided on the substrate surface to increase the heat exchange area, thereby achieving passive heat dissipation combining heat conduction diffusion and convection heat transfer.

[0055] In some embodiments, the thermoelectric cooler sequentially includes: a first conductive circuit layer 221, a first electrical connection layer, a P / N semiconductor heat dissipation module 3, a second electrical connection layer, a second conductive circuit layer 41, a thermally conductive substrate 4, and a power supply interface 42 disposed on the second surface 22 of the support substrate 2; the second conductive circuit layer 41 is electrically connected to the power supply interface 42; the P / N semiconductor heat dissipation module 3 includes an array of thermoelectric units 31, which are electrically connected in series and thermally connected in parallel through the first and second conductive circuit layers to form a thermoelectric cooling circuit; the thermoelectric units 31 and the periphery of the P / N semiconductor heat dissipation module 3 are filled with thermally conductive and insulating encapsulation material 32. It should be noted that the thermoelectric cooler actively extracts heat from the working area of ​​the Micro-LED light-emitting module; the cooperation of the first and second conductive circuit layers to form an electrically connected in series and thermally connected in parallel circuit of the thermoelectric units is beneficial to improving cooling efficiency and heat pump capability; at the same time, the use of thermally conductive and insulating encapsulation material helps to maintain electrical insulation while assisting in heat diffusion and structural fixation, thereby improving the encapsulation reliability and operational stability of the thermoelectric cooler. When current flows through the power supply interface 42 along the thermoelectric heat dissipation circuit, the second surface 22 of the support substrate 2 forms a low-temperature side that is thermally connected to the Micro-LED light-emitting module 6, while the side of the thermally conductive substrate 4 facing away from the P / N semiconductor heat dissipation module 3 forms a high-temperature side, and heat is conducted to the hot-end heat dissipation path through the thermally conductive substrate 4. Furthermore, compared to an externally heated thermoelectric cooler solution, directly integrating the thermoelectric cooler into the support substrate of the Micro-LED display module eliminates the need for an intermediate thermally conductive layer. This not only simplifies the structure and reduces material and manufacturing costs, but also improves heat dissipation efficiency by reducing the number of interfaces in the heat conduction path.

[0056] In some embodiments, the first electrical connection layer and the second electrical connection layer are at least one of a solder layer, a sintered metal layer, a transient liquid phase diffusion connection layer, or a conductive connection layer; the thermally conductive insulating encapsulation material 32 is a thermally conductive insulating potting compound or a thermally conductive insulating composite encapsulation material; the side of the thermally conductive substrate 4 facing away from the P / N semiconductor heat dissipation module is provided with at least one of a surface microstructure 11, a heat spreader, a heat sink, a metal shell, or a thermally conductive diffusion plate. It should be noted that the various forms of electrical connection layers provide process selection space for thermoelectric coolers, which can be matched according to cost, temperature, and reliability requirements; the thermally conductive insulating potting compound or the thermally conductive insulating composite encapsulation material can take into account insulation, thermal conductivity, and mechanical support; adding a surface microstructure, a heat spreader, a heat sink, a metal shell, or a thermally conductive diffusion plate to the back of the thermally conductive substrate is beneficial for the rapid diffusion and dissipation of heat from the hot end, preventing heat accumulation at the hot end from weakening the cooling effect.

[0057] In some embodiments, the Micro-LED display module further includes a control unit, which is electrically connected to the power supply interface 42 of the thermoelectric cooler and configured to adjust the current magnitude and direction of the thermoelectric heat dissipation circuit according to the temperature signal of the Micro-LED light-emitting module 6. It should be noted that the control unit can realize dynamic, closed-loop regulation of the thermoelectric cooler, enabling the system to adaptively adjust its cooling capacity according to the actual heating state, avoiding increased energy consumption or temperature fluctuations caused by continuous full-power operation, thereby improving temperature control accuracy, response speed, and system energy efficiency, and helping to maintain the brightness and color stability of the Micro-LED display module.

[0058] This application also provides a method for fabricating the above-mentioned thermally improved Micro-LED display module, including the following steps: S1. Provide a support substrate 2, and perform planarization, cleaning and surface activation treatment on the support substrate 2; S2. A surrounding wall 10 is provided on the first surface of the support substrate 2. The surrounding wall 10 is formed by three side walls to form a U-shaped groove 101 with an open end. The printed circuit board 7 is fixed on the open end side. S3. Place the Micro-LED light-emitting module 6 in the U-shaped groove 101 and fix it to the first surface 21 of the support substrate 2 by means of the adhesive metal layer 8; connect the Micro-LED light-emitting module 6 to the printed circuit board 7 by means of gold wire; the Micro-LED light-emitting module 6 is in direct contact with the enclosure 10, or the Micro-LED light-emitting module 6 is thermally connected to the enclosure 10 by means of the heat-conducting medium 5. S4. A thermal management structure is fabricated on the second surface 22 of the support substrate 2. It should be noted that by defining the core steps such as support substrate processing, enclosure setting, light-emitting module mounting and thermal connection formation, and thermal management structure fabrication, a complete fabrication path matching the Micro-LED display module structure is established. This enables the thermal connection path and thermal management structure to be effectively realized during the manufacturing stage, helping to ensure that the resulting Micro-LED display module has stable thermal management performance and mass production feasibility.

[0059] In some embodiments, the preparation method further includes: S5. A transparent encapsulation layer 1 is covered on the top surface of the U-shaped groove 101 and fixed to the top surface of the enclosure 10 with an adhesive to seal the enclosed space. S6. Prepare a first surface microstructure on the outer surface of the enclosure 10; S7. The prepared Micro-LED display module is cured, inspected, trimmed, cleaned, and its performance calibrated. It should be noted that the above steps further improve the encapsulation integrity and external protection capabilities of the Micro-LED display module; enhance peripheral heat dissipation performance by increasing the microstructure on the outer surface of the enclosure; and improve the consistency and reliability of the finished product through curing, inspection, trimming, cleaning, and performance calibration, thereby making the final product more stable in optical, electrical, and thermal performance.

[0060] The following are some embodiments of this application, and the embodiments of the present invention will further describe the technical solution of the present invention in detail. Example 1

[0061] This embodiment provides a Micro-LED display module with improved thermal management, such as... Figure 1 , 2 As shown, it includes: a transparent encapsulation layer 1, a support substrate 2, a P / N semiconductor heat dissipation module 3, a thermally conductive substrate 4, a thermally conductive medium 5, a Micro-LED light-emitting module 6, a printed circuit board 7, an adhesive metal layer 8, and a surrounding wall 10. The support substrate 2 has a first surface 21 and a second surface 22 facing away from each other, and the surrounding wall 10 is provided on the first surface 21. Figure 3 As shown, the enclosure 10 is formed by three side walls enclosing a U-shaped groove 101 with an open end. The printed circuit board 7 is disposed on the outside of the open end, and the transparent encapsulation layer 1 covers the top of the U-shaped groove 101, together with the enclosure 10 to form a closed cavity. The Micro-LED light-emitting module 6 is placed in the closed cavity and is fixed to the first surface 21 of the support substrate 2 by an adhesive metal layer 8. A filling gap is formed between the Micro-LED light-emitting module 6 and the enclosure 10, and a heat-conducting medium 5 is disposed in the filling gap. A thermoelectric cooler is disposed on the second surface 22 of the support substrate 2.

[0062] The supporting substrate 2 and the surrounding wall 10 are made of aluminum nitride ceramic and are integrally formed from the same material. The width of the gap is 20μm, and the thermally conductive medium 5 is thermally conductive silver paste. The bonding metal layer 8 is made of die-bonding silver paste or gold-tin alloy and has a thickness of 50μm. The Micro-LED light-emitting module 6 includes a CMOS driving substrate and a high-density Micro-LED chip array electrically connected by bonding. The printed circuit board 7 is an FR4 printed circuit board, which has printed circuits 71 and pads 72. The pads 72 are electrically connected to the Micro-LED light-emitting module 6 through gold wires.

[0063] Specifically, such as Figure 2-9 As shown, the thermoelectric cooler sequentially includes: a first conductive circuit layer 221, a first electrical connection layer, a P / N semiconductor heat dissipation module 3, a second electrical connection layer, a second conductive circuit layer 41, a thermally conductive substrate 4, and a power supply interface 42. The first conductive circuit layer 221 is disposed on the second surface 22 of the supporting substrate 2, and the second conductive circuit layer 41 is disposed on one side of the thermally conductive substrate 4, and is electrically connected to the power supply interface 42. The P / N semiconductor heat dissipation module 3 includes an array of thermoelectric units 31, each including a P-type thermoelectric unit 311 and an N-type thermoelectric unit 312. The P-type thermoelectric units 311 and N-type thermoelectric units 312 are electrically connected in series and thermally connected in parallel via the first conductive circuit layer 221 and the second conductive circuit layer 41 to form a thermoelectric heat dissipation circuit. Thermally conductive insulating encapsulation material 32 is filled between the thermoelectric units 31 and around the periphery of the P / N semiconductor heat dissipation module 3.

[0064] The thermoelectric unit 31 has a rectangular cross-section and its height is perpendicular to the supporting substrate 2. P-type thermoelectric units 311 and N-type thermoelectric units 312 are arranged alternately in an M×N two-dimensional matrix, where M and N are both positive integers greater than 1. The first electrical connection layer and the second electrical connection layer are solder layers; the thermally conductive and insulating encapsulation material 32 is a thermally conductive and insulating potting compound.

[0065] In this embodiment, the heat generated by the Micro-LED light-emitting module 6 during operation is dissipated through a dual-path collaborative cooling system: In the horizontal path, some heat diffuses to the surrounding environment via thermal conduction and natural convection through the thermally conductive medium 5 and the surrounding wall 10, achieving passive heat dissipation. In the vertical path, the remaining heat is efficiently conducted to the thermoelectric cooler through the high thermal conductivity bonding metal layer 8 and the supporting substrate 2, activating the active temperature control cooling mechanism. The thermoelectric cooler operates based on the Peltier effect: when current flows along the thermoelectric cooling circuit through the power supply interface 42, the second surface 22 of the supporting substrate 2 can form a low-temperature side that is thermally connected to the Micro-LED light-emitting module 6, while the side of the thermally conductive substrate 4 facing away from the P / N semiconductor heat dissipation module 3 forms a high-temperature side, and heat is conducted to the hot-end heat dissipation path through the thermally conductive substrate 4.

[0066] This embodiment also provides a method for preparing the above-mentioned Micro-LED display module, including the following steps: Step S1: Provide a support substrate 2 and a surrounding wall 10. The surrounding wall 10 is disposed on the first surface 21 of the support substrate 2. The support substrate 2 and the surrounding wall 10 are made of the same material and integrally formed. The surrounding wall 10 is formed by three side walls enclosing a U-shaped groove 101 with an open end. The support substrate 2 is subjected to planarization, cleaning, and surface activation treatment. The planarization treatment uses chemical mechanical polishing, the cleaning treatment uses ultrasonic cleaning and drying, and the surface activation treatment uses plasma treatment.

[0067] Step S2: Fix the printed circuit board 7 to the open end of the U-shaped groove 101. The printed circuit board 7 is an FR4 printed circuit board.

[0068] Step S3: Place the Micro-LED light-emitting module 6 in the U-shaped groove 101 and fix it to the first surface 21 of the support substrate 2 by bonding the metal layer 8; electrically connect the Micro-LED light-emitting module 6 to the printed circuit board 7 through gold wires; the Micro-LED light-emitting module 6 is in direct contact with the enclosure 10, or the Micro-LED light-emitting module 6 is thermally connected to the enclosure 10 through the heat-conducting medium 5.

[0069] Step S4: Fabricate a thermoelectric cooler on the second surface 22 of the support substrate 2. Specifically, a first conductive circuit layer 221 is fabricated on the second surface 22 of the support substrate 2; a thermally conductive substrate 4 is provided, and a second conductive circuit layer 41 is fabricated on one side of the thermally conductive substrate 4; P-type thermoelectric units 311 and N-type thermoelectric units 312 are fabricated respectively; the P-type thermoelectric units 311 and N-type thermoelectric units 312 are alternately arranged on the first conductive circuit layer 221 and connected to the first conductive circuit layer 221 through a first electrical connection layer; the thermally conductive substrate 4 is aligned with the P-type thermoelectric units 311 and N-type thermoelectric units 312 and connected to the second conductive circuit layer 41 through a second electrical connection layer to form a thermoelectric heat dissipation circuit that is electrically connected in series and thermally connected in parallel; a thermally conductive insulating encapsulation material 32 is used to fill the gap between the P-type thermoelectric units 311 and N-type thermoelectric units 312 and the periphery of the thermoelectric cooler, and then cured and tested for electrothermal performance.

[0070] Step S5: Cover the top surface of the U-shaped groove 101 with a transparent encapsulation layer 1 and fix it to the top surface of the enclosure 10 with an adhesive to seal the enclosed space.

[0071] Step S6: Curing, testing, trimming, cleaning, and performance calibration of the prepared Micro-LED display module.

[0072] In this embodiment, a first surface microstructure can also be prepared on the outer side of the enclosure 10; the side of the thermally conductive substrate 4 away from the P / N semiconductor heat dissipation module 3 can be further thermally connected to at least one of the surface microstructure 11, heat spreader, heat sink, metal shell or thermally conductive diffusion plate to form a heat dissipation path at the hot end.

[0073] In this embodiment, the Micro-LED display module may also be equipped with a control unit. The control unit is electrically connected to the power supply interface 42 and receives feedback signals from temperature sensors disposed on the CMOS driving substrate and / or support substrate 2. When the module operates under conditions of high brightness, large duty cycle or large current driving, the control unit can adjust the current magnitude and direction of the thermoelectric heat dissipation circuit according to the temperature feedback results to regulate the operating temperature of the Micro-LED light-emitting module 6.

[0074] It should be noted that the active temperature control function of the thermoelectric cooler in this embodiment is conditional on the hot end heat dissipation path having corresponding heat dissipation capacity; when the hot end heat dissipation conditions are met, it can work with the support substrate 2 and the first surface microstructure to reduce the overall thermal resistance of the Micro-LED light-emitting module 6 to the external environment and improve the temperature distribution during the operation of the module. Example 2

[0075] The Micro-LED display module in this embodiment is largely the same as that in Embodiment 1, with the main difference being the thermal management structure on the second surface 22 of the supporting substrate 2. In this embodiment, a thermoelectric cooler is not provided; instead, a passive heat dissipation structure is provided on the second surface 22 of the supporting substrate 2. The following will describe this in conjunction with… Figures 10 to 12 Please provide a detailed explanation.

[0076] The passive heat dissipation structure in this embodiment specifically includes: an adhesive layer 12, a high thermal conductivity rod 13, and a substrate 9 sequentially disposed on the second surface 22 of the supporting substrate 2. The high thermal conductivity rod 13 can be made of materials such as copper, steel, or aluminum nitride. The supporting substrate 2, adhesive layer 12, high thermal conductivity rod 13, and substrate 9 can be formed into an integrated structure using the same material, or they can be combined using two or more materials. Gaps can be maintained between the high thermal conductivity rods 13 to form heat dissipation channels, and surface microstructures 11, such as through holes, grooves, or concave hemispherical array structures, can be provided on the surface of the substrate 9.

[0077] In this embodiment, the heat generated by the Micro-LED light-emitting module 6 during operation can diffuse laterally to the periphery of the module through the thermal connection with the enclosure 10. Furthermore, the heat conducted to the second surface 22 of the supporting substrate 2 can be further transferred to the high thermal conductivity rod 13 via the adhesive layer 12, and rapidly diffuse along the length of the high thermal conductivity rod 13 to the larger area of ​​the substrate 9. Since gaps are maintained between the high thermal conductivity rods 13, heat dissipation channels that facilitate airflow can be formed. Simultaneously, the surface microstructures 11 on the substrate 9 can further increase the heat exchange area and enhance natural convection heat transfer with the ambient air. Therefore, this embodiment not only constructs a low thermal resistance longitudinal heat diffusion path through the high thermal conductivity rods 13 and the substrate 9, but also works synergistically with the additional lateral heat dissipation channels formed by the enclosure 10, dispersing and discharging heat in both directions on the first surface 21 and the second surface 22, thereby reducing local hot spots, improving temperature uniformity, and achieving stable passive heat dissipation without introducing active cooling devices. Example 3

[0078] The Micro-LED display module in this embodiment is largely the same as that in Embodiment 2, with the main difference being the different thermal management structure on the second surface 22 of the supporting substrate 2. The following will combine... Figures 13 to 15 Please provide a detailed explanation.

[0079] In this embodiment, surface microstructures 11, such as through holes, grooves, concave hemispherical arrays or bump structures, are directly provided on the second surface 22 of the support substrate 2; the heat exchange area is increased by the surface microstructures 11 on the second surface 22 of the support substrate 2 to achieve passive heat dissipation.

[0080] The above description is merely a preferred embodiment of the present invention, used to illustrate the technical solution of the present invention, and not to limit the scope of protection of the present invention. Equivalent substitutions or modifications made by those skilled in the art without departing from the concept of the present invention should all fall within the scope of protection of the present invention.

Claims

1. A Micro-LED display module with improved thermal management, characterized in that, include: A support substrate having a first surface and a second surface facing away from each other; A wall is provided on the first surface of the supporting substrate and encloses a receiving space; The Micro-LED light-emitting module is fixed to the first surface of the supporting substrate by an adhesive metal layer and placed within the receiving space formed by the enclosure wall; A thermal management structure is disposed on the second surface of the supporting substrate; The Micro-LED light-emitting module is thermally connected to the enclosure wall.

2. The Micro-LED display module with improved thermal management according to claim 1, characterized in that, The Micro-LED light-emitting module is thermally connected to the enclosure in the following ways: the Micro-LED light-emitting module is in direct contact with the enclosure; or, a filling gap is formed between the Micro-LED light-emitting module and the enclosure, and a heat-conducting medium is provided in the filling gap.

3. The Micro-LED display module with improved thermal management according to claim 2, characterized in that, The thermally conductive medium is at least one of thermally conductive silver paste, thermally conductive gel, thermally conductive silicone grease, or phase change thermally conductive material, and the width of the filling gap is 10μm to 200μm.

4. The Micro-LED display module with improved thermal management according to claim 1, characterized in that: The thermal conductivity of the material used to make the supporting substrate and the enclosure is not less than 20 W / (m·K).

5. The Micro-LED display module with improved thermal management according to claim 1, characterized in that: The materials used to make the support substrate and the enclosure are selected from at least one of aluminum nitride ceramic, alumina ceramic, diamond, aluminum nitride / resin composite material, boron nitride / resin composite material and alumina / resin composite material; the support substrate and the enclosure are integrally formed from the same material.

6. The Micro-LED display module with improved thermal management according to claim 1, characterized in that: The height of the enclosure is 5μm to 50μm greater than the sum of the thicknesses of the Micro-LED light-emitting module and the bonding metal layer; a first surface microstructure is provided on the outer side of the enclosure.

7. The Micro-LED display module with improved thermal management according to claim 6, characterized in that: The first surface microstructure is at least one of the following: a groove array, a bump array, a through-hole structure, an inward hemispherical array, and an outward convex hemispherical array.

8. The Micro-LED display module with improved thermal management according to claim 1, characterized in that: The Micro-LED display module further includes a transparent encapsulation layer and a printed circuit board; the enclosure is formed by three side walls to create a U-shaped groove with an open end, the printed circuit board is located outside the open end, and the transparent encapsulation layer covers the top of the U-shaped groove, together with the enclosure to form a closed cavity; the transparent encapsulation layer is a cover glass, a filter, or a stacked structure of cover glass and filter; the printed circuit board is an FR4 printed circuit board, which has printed circuits and pads, and the pads are electrically connected to the Micro-LED light-emitting module through gold wires.

9. The Micro-LED display module with improved thermal management according to claim 1, characterized in that: The bonding metal layer is made of die-bonding silver paste or gold-tin alloy, and the thickness of the bonding metal layer is 5μm to 50μm; the thermal management structure is at least one of surface microstructure, thermally conductive diffusion structure, and thermoelectric cooler.

10. The Micro-LED display module with improved thermal management according to claim 9, characterized in that: The surface microstructure is at least one of the following: groove array, bump array, through-hole structure, concave hemispherical array, and convex hemispherical array.

11. The Micro-LED display module with improved thermal management according to claim 9, characterized in that: The thermally conductive diffusion structure comprises, in sequence: an adhesive layer disposed on the second surface of the supporting substrate, high thermal conductivity rods, and a substrate; gaps are maintained between the high thermal conductivity rods to form heat dissipation channels.

12. The Micro-LED display module with improved thermal management according to claim 9, characterized in that, The thermoelectric cooler sequentially comprises: a first conductive circuit layer, a first electrical connection layer, a P / N semiconductor heat dissipation module, a second electrical connection layer, a second conductive circuit layer, a thermally conductive substrate, and a power supply interface disposed on the second surface of the supporting substrate; the second conductive circuit layer is electrically connected to the power supply interface; the P / N semiconductor heat dissipation module comprises an array of thermoelectric units, which are electrically connected in series and thermally connected in parallel through the first conductive circuit layer and the second conductive circuit layer to form a thermoelectric cooling circuit; the thermoelectric units and the periphery of the P / N semiconductor heat dissipation module are filled with thermally conductive insulating encapsulation material.

13. The Micro-LED display module with improved thermal management according to claim 12, characterized in that: The first electrical connection layer and the second electrical connection layer are at least one of solder layer, sintered metal layer, transient liquid phase diffusion connection layer or conductive connection layer; the thermally conductive insulating encapsulation material is thermally conductive insulating potting compound or thermally conductive insulating composite encapsulation material. The thermally conductive substrate has at least one of the following on the side opposite to the P / N semiconductor heat dissipation module: surface microstructure, heat spreader, heat sink, metal shell, or thermally conductive diffusion plate.

14. The Micro-LED display module with improved thermal management according to claim 12, characterized in that: The Micro-LED display module also includes a control unit, which is electrically connected to the power supply interface of the thermoelectric cooler and configured to adjust the current magnitude and direction of the thermoelectric heat dissipation circuit according to the temperature signal of the Micro-LED light-emitting module.

15. A method for fabricating a Micro-LED display module with improved thermal management according to any one of claims 1-14, characterized in that, Includes the following steps: S1. Provide a support substrate, and perform planarization, cleaning and surface activation treatment on the support substrate; S2. A surrounding wall is provided on the first surface of the support substrate. The surrounding wall is formed by three side walls to form a U-shaped groove with an open end. A printed circuit board is fixed on the open end side. S3. Place the Micro-LED light-emitting module in the U-shaped groove and fix it to the first surface of the supporting substrate by bonding a metal layer; electrically connect the Micro-LED light-emitting module to the printed circuit board through gold wires; the Micro-LED light-emitting module is in direct contact with the enclosure wall, or the Micro-LED light-emitting module is thermally connected to the enclosure wall through a heat-conducting medium. S4. A thermal management structure is prepared on the second surface of the support substrate.

16. The preparation method according to claim 15, characterized in that, The preparation method further includes: S5. Cover the top surface of the U-shaped groove with a transparent encapsulation layer and fix it to the top surface of the enclosure wall with an adhesive to seal the enclosed space; S6. Prepare a first surface microstructure on the outer side of the enclosure; S7. Curing, testing, trimming, cleaning, and performance calibration of the prepared Micro-LED display module.

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