An ultrathin liquid metal matrix composite packaging structure and method for a flexible micro-pump heat dissipation device

Abstract

The application belongs to the technical field of packaging and specifically relates to an ultrathin liquid metal-based composite packaging structure and method for a flexible micro-pump heat dissipation device. The composite packaging structure comprises a first polymer layer, a nano-metal connecting layer, an ultrathin liquid metal sealing layer and a second polymer layer. The first polymer layer is coated on the outside of the object to be packaged. The ultrathin liquid metal sealing layer is coated on the nano-metal connecting layer, and the nano-metal connecting layer is between the first polymer layer and the second polymer layer. The second polymer layer is connected to the edge of the first polymer layer. Compared with the prior art, the application solves the problems of the liquid metal packaging in the prior art, such as large thickness, heavy quality, high cost, and easy separation of the liquid metal and the polymer layer during the flexible bending process, which leads to sealing failure. The present scheme realizes flexible and bend-resistant high-barrier packaging by using the liquid metal in combination with the nano-metal connecting layer.

Description

Technical Field

[0001] This invention belongs to the field of packaging technology, specifically relating to an ultrathin liquid metal-based composite packaging structure and method for flexible micropump heat dissipation devices. Background Technology

[0002] In mobile devices, with the continuous improvement of processor performance and the increasing complexity of applications, the heat generated during operation also increases significantly, leading to elevated device temperatures and impacting performance and user experience. Therefore, effective heat dissipation technology has become a critical aspect of mobile device design.

[0003] Micropump fluid cooling, as a novel heat dissipation method, has received widespread attention in recent years. Micropump fluid cooling devices conduct and dissipate heat through a fluid medium, achieving highly efficient heat dissipation. Its working principle involves a micropump driving a cooling fluid to circulate within the device, transferring the generated heat from the heat-generating element to the heat dissipation area and releasing it to the outside. Compared to traditional thermal conductive sheets and graphite heat sinks, micropump fluid cooling devices achieve more efficient heat conduction and can precisely control the heat dissipation path, making thermal management more proactive and flexible. For example, patent CN116456674A provides a terminal heat dissipation device and a heat dissipation technology for mobile terminals. This technology achieves highly efficient heat dissipation by driving a fluid working medium to circulate within the device using a micropump. Specifically, the heat dissipation device includes a heat flow cavity, a micropump, a heat pool, and control components. The first sidewall of the heat flow cavity is directly in contact with the main heat-generating element of the mobile terminal through a thermally conductive interface material, forming a surface-area heat conduction interface. Its internal circulation channel is formed by the first sidewall, the second sidewall, and a support wall, within which the fluid working medium flows continuously. The heat generated by the mobile terminal is conducted to the fluid working medium through the first sidewall. The flowing working medium evenly distributes the heat to other parts of the heat flow cavity, and finally the heat is dissipated outward through the second sidewall or the heat pool. The control component is responsible for transferring the electrical energy of the mobile terminal to the micropump, or directly powering the micropump, thereby achieving efficient operation of the heat dissipation system.

[0004] In flexible micropump fluid heat dissipation devices used in flexible electronic devices, the evaporation failure of the working fluid is one of the main factors affecting its long-term stability. The working fluid continuously circulates in the fluid channels of the device, absorbing and transferring heat. However, due to long-term fluid circulation and temperature fluctuations, especially in high-temperature environments, some of the working fluid may gradually evaporate, reducing the total fluid volume and affecting the system's heat dissipation efficiency and fluid pressure. Furthermore, due to the compact structure of micropump fluid heat dissipation devices, replenishing or replacing the working fluid is difficult. Once evaporation failure occurs, the entire system usually needs to be replaced, increasing maintenance costs and inconvenience. Existing polymer encapsulation layers lack sufficient sealing performance to meet the sealing requirements during heat dissipation. Exploring and designing encapsulation structures and their fabrication methods for micropump heat dissipation devices to achieve long-term effective encapsulation and stable performance is a problem urgently needing to be solved by those skilled in the art. For example, patent CN202010447880.2 proposes an ultra-thin flexible heat dissipation device suitable for flexible electronic devices, which uses aluminum-plastic film shell material and gradient wettability capillary core, and has high heat transfer efficiency and bending performance. However, it has the problem that long-term bending will lead to a decrease in sealing performance.

[0005] Liquid metal possesses high airtightness, high fluidity, and high thermal conductivity. Encapsulation with liquid metal can reduce the evaporation loss of the working fluid, making it a promising novel sealing device for micro-pump fluid cooling devices. For example, patent CN202310055877.X provides a liquid metal-based encapsulation structure with a water vapor permeability 5-6 orders of magnitude lower than that of traditional polymer PDMS, while maintaining excellent sealing performance under stretching. However, the liquid metal encapsulation prepared by this method has a large liquid metal layer thickness, increasing cost and reducing the usable space inside flexible electronic devices. For example, patent CN202310056082.0 provides a flexible, stretchable layered composite structure containing liquid metal, which has excellent water and oxygen barrier properties and is flexible and stretchable. However, its liquid metal layer is formed by vacuum injection, resulting in a large thickness, increasing cost and hindering its use in thin and light flexible electronic devices.

[0006] Therefore, it is necessary to prepare an ultrathin liquid metal-based composite packaging structure for flexible micropump heat dissipation devices to ensure the reliability of micropump heat dissipation devices in daily use, extend their service life in heat dissipation structures of electronic devices such as flexible screens and foldable phones, and meet the stringent requirements of these electronic devices for thickness and weight. Summary of the Invention

[0007] The purpose of this invention is to provide an ultrathin liquid metal-based composite encapsulation structure and method for flexible micropump heat dissipation devices, addressing the problems of existing liquid metal sealing encapsulations, such as large thickness, heavy weight, high cost, and easy separation of the liquid metal and polymer layer during flexible bending, leading to sealing failure. This solution utilizes a nano-metal connecting layer to construct an ultrathin liquid metal sealing layer, combined with a flexible polymer layer, achieving a flexible and bend-resistant high-barrier encapsulation technology. This improves the service life of flexible bendable devices while reducing their thickness and cost.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] The first aspect of this invention discloses an ultrathin liquid metal-based composite packaging structure for a flexible micropump heat dissipation device, used to package an object to be packaged. The composite packaging structure includes a first polymer layer, a nano-metal connecting layer, an ultrathin liquid metal sealing layer, and a second polymer layer.

[0010] The first polymer layer covers the outside of the object to be packaged, forming an inner packaging structure;

[0011] The ultrathin liquid metal sealing layer is coated on the nano-metal connecting layer, which is located between the first polymer layer and the second polymer layer, forming an intermediate layer structure between the ultrathin liquid metal sealing layer and the nano-metal connecting layer.

[0012] The second polymer layer is connected to the first polymer layer to form an outer encapsulation structure.

[0013] Preferably, the liquid metal in the ultrathin liquid metal sealing layer is selected from gallium-based, indium-based, and bismuth-based liquid metals.

[0014] Preferably, the thickness of the ultrathin liquid metal sealing layer is between 10 and 50 μm.

[0015] Preferably, the nanometal in the nanometal bonding layer is selected from gold, silver, copper, and indium, etc.

[0016] Preferably, the thickness of the nano-metal interconnect layer is between 20-200 nm.

[0017] Preferably, the first polymer layer and the second polymer layer are flexible organic polymer materials;

[0018] The flexible organic polymer material is selected from thermoplastic flexible organic polymers and thermosetting flexible organic polymers.

[0019] Preferably, the thickness of the first polymer layer is 0.001-5 mm, and the thickness of the second polymer layer is 0.001-5 mm.

[0020] Preferably, the second polymer layer is connected to the first polymer layer by means of thermo-press bonding, adhesive bonding, chemical cross-linking bonding, or interpenetrating network structure.

[0021] Preferably, the second polymer layer is connected to the first polymer layer by thermo-pressing.

[0022] Preferably, the object to be encapsulated is a liquid microchannel of a flexible micropump heat dissipation device.

[0023] The second aspect of this invention discloses an ultrathin liquid metal-based composite packaging method for flexible micropump heat dissipation devices, comprising the following steps:

[0024] Step 1: Deposit a nano-metal interconnect layer on the surface of the first polymer layer and / or the second polymer layer;

[0025] Step 2: Surround and seal the object to be packaged with the first polymer layer;

[0026] Step 3: Apply liquid metal onto the nano-metal bonding layer under oxygen-free conditions to form an ultrathin liquid metal sealing layer;

[0027] Step 4: Surround the ultrathin liquid metal sealing layer with the second polymer layer, and connect the first polymer layer with the second polymer layer to obtain the composite encapsulation structure as described above.

[0028] Preferably, the deposition is a thin film deposition method, including thermal evaporation, physical vapor deposition, chemical vapor deposition, magnetron sputtering, and electrochemical deposition.

[0029] The working principle of this invention is as follows:

[0030] The first and second polymer layers ensure the flexibility and bendability of the composite packaging structure, while the ultra-thin liquid metal sealing layer between them guarantees the extremely high airtightness of the composite packaging structure under normal operating temperatures.

[0031] Based on this, in order to ensure that the ultrathin liquid metal sealing layer and the polymer layer can still maintain close contact when the flexible packaging structure is frequently deformed, a nano-metal connecting layer is deposited on at least one side of the polymer layer to improve the adhesion of the liquid metal on the polymer layer, ensuring that the liquid metal can be tightly bonded between the two polymer layers in any state, thereby ensuring high sealing performance.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) By fully utilizing the metallic and fluid properties of liquid metal and combining it with the bending resistance of polymer layers, a flexible, bend-resistant, gas-barrier, layered composite encapsulation structure was obtained. This composite encapsulation structure can be well applied to various devices with flexible application requirements, such as those with volatile liquids, deformable systems with high sealing requirements, and bend-resistant systems.

[0034] (2) The setting of the nano-metal connection layer can facilitate the preparation of an ultra-thin and dense (10-50μm) liquid metal sealing layer, providing effective and long-term stable sealing and barrier performance for ultra-thin devices with large deformation and large bending. Attached Figure Description

[0035] Figure 1 This is a side cross-sectional view of the composite packaging structure and the object to be packaged.

[0036] Figure 2 The results of working fluid leakage tests on the composite packaging structures prepared in Example 1 and Comparative Example 1 are as follows;

[0037] In the figure: 1. First polymer layer, 2. Nanometal bonding layer, 3. Ultrathin liquid metal sealing layer, 4. Second polymer layer, 5. Object to be encapsulated. Detailed Implementation

[0038] To better understand the above technical solutions, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only some examples, and not all. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0039] The terminology used in the embodiments of this invention is for describing specific embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” include the plural forms in the embodiments and claims of this invention unless the context clearly indicates otherwise. “Multiple” generally includes at least two.

[0040] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. The steps or actions in the method description can also be rearranged or modified by those skilled in the art in an obvious order. Therefore, the order in the specification and drawings is only for clearly describing a particular embodiment, and the order is not mandatory unless specifically stated otherwise.

[0041] The part numbers in this article, such as "first" and "second", are used only to distinguish objects and have no sequential or technical meaning.

[0042] Unless otherwise specified, the reagents used in the following description are commercially available products, and the methods used are those known in the art.

[0043] The present invention aims to provide an ultrathin liquid metal-based composite packaging structure for flexible micropump heat dissipation devices. This composite packaging structure is flexible, bend-resistant, and has high hermeticity, and a method for fabricating this composite packaging structure is also provided. The ultrathin liquid metal sealing layer constructed using liquid metal achieves a flexible, bend-resistant, and high-barrier packaging technology, thereby improving the service life of flexible bendable devices while reducing their thickness and cost.

[0044] Specifically, the composite packaging structure sequentially includes the object to be packaged (which may be the liquid microchannel of a commercial flexible micropump radiator), a first polymer layer, a nano-metal connecting layer, an ultrathin liquid metal sealing layer, and a second polymer layer; the ultrathin liquid metal sealing layer is located between the first and second polymer layers; and a nano-metal connecting layer is provided on the side of the first polymer layer and / or the second polymer layer facing the ultrathin liquid metal sealing layer.

[0045] The first and second polymer layers ensure the flexibility and bendability of the composite packaging structure, while the ultrathin liquid metal sealing layer between them guarantees extremely high airtightness of the composite structure under normal operating temperatures. Furthermore, to ensure that the ultrathin liquid metal sealing layer and the polymer layer maintain tight contact even during frequent deformation of the flexible packaging structure, a nano-metal bonding layer needs to be deposited on the polymer layer to improve the adhesion of the liquid metal to the polymer layer, ensuring that the liquid metal is tightly bonded between the two polymer layers, thereby guaranteeing high sealing performance.

[0046] This invention demonstrates a flexible and bendable composite packaging structure based on ultrathin liquid metal by introducing a nano-metal connecting layer and an ultrathin liquid metal sealing layer on a polymer layer. It has a low water vapor permeability, which can effectively block the penetration of water vapor and other gases, and improve the service life of flexible and bendable devices. At the same time, the sealing structure can also meet the thickness requirements of flexible and bendable devices and reduce the cost of using the sealing structure.

[0047] Furthermore, the liquid metal in the ultrathin liquid metal sealing layer is selected from gallium-based liquid metals, indium-based liquid metals, and bismuth-based liquid metals, etc. By using ultrathin liquid metal as the sealing layer, its characteristics of combining metallic and room-temperature fluid properties are fully utilized, providing the packaging structure with flexibility, bend resistance, and excellent sealing performance. Unlike solid metals, which cannot meet the packaging requirements of flexible devices due to their limited bend resistance, the application of liquid metal effectively overcomes the shortcomings of existing technologies in terms of sealing and bend resistance, bringing broader application prospects to flexible packaging.

[0048] Furthermore, the thickness of the first polymer layer is 0.001-5 mm, and the thickness of the second polymer layer is 0.001-5 mm; both the first and second polymer layers are flexible organic polymer materials, including thermoplastic flexible organic polymers, thermosetting flexible organic polymers, and combinations thereof. To achieve the effective utilization of liquid metal in industrial applications, this invention uses a polymer layer encapsulation shell. This not only maintains the amorphous state of the liquid metal, allowing for designability in size and shape, but also meets the needs of actual production and use, thereby promoting the industrial application of liquid metal in the encapsulation field.

[0049] Furthermore, the thickness of the ultrathin liquid metal sealing layer is between 10-50 μm to meet sealing requirements while ensuring the overall lightweight design of the device. If the liquid metal sealing layer is too thin, it will not be able to guarantee sufficient moisture barrier performance, while if it is too thick, it will increase the overall thickness, weight, and cost.

[0050] Furthermore, the metal in the nano-metal bonding layer is selected from gold, silver, copper, indium, etc. Based on the superior wettability of liquid metal in these metals, the nano-metal bonding layer ensures close contact between the ultra-thin liquid metal sealing layer and the polymer layer, further guaranteeing the sealing performance.

[0051] Furthermore, the thickness of the nano-metal bonding layer is between 20-200 nm to ensure the formation of a continuous metal film while saving costs, making it suitable for the needs of large-scale industrial production.

[0052] Furthermore, based on the flexible and bend-resistant layered composite packaging structure, the present invention can further provide a packaging component, comprising:

[0053] The inner encapsulation structure is formed by a first polymer layer surrounding and sealing the object to be encapsulated.

[0054] The outer encapsulation structure is formed by a second polymer layer surrounding and sealing an ultrathin liquid metal sealing layer;

[0055] The intermediate layer structure comprises a nano-metal connecting layer and an ultrathin liquid metal sealing layer. The first polymer layer and / or the second polymer layer have a nano-metal connecting layer on the side facing the ultrathin liquid metal sealing layer. The liquid metal layer is situated between the inner packaging structure and the nano-metal connecting layer, and / or the outer packaging structure and the nano-metal connecting layer. Through the design of the aforementioned inner packaging structure, intermediate layer structure, and outer packaging structure, the liquid metal effectively covers the bendable device, balancing flexibility and sealing, thereby achieving effective moisture barrier and ensuring the long-term stability and safety of the internal devices.

[0056] Furthermore, under normal and bending conditions, its internal working fluid exhibits virtually no evaporation.

[0057] The present invention also provides a method for preparing the above-mentioned composite packaging structure and package, comprising the following steps:

[0058] Step 1: Deposit a metal bonding layer with a thickness of 20-200 nm on at least one surface of the first polymer layer and / or the second polymer layer using thin film deposition methods such as thermal evaporation, physical vapor deposition, chemical vapor deposition, magnetron sputtering, or electrochemical deposition.

[0059] Step 2: Cover and seal the object to be packaged with the first polymer layer;

[0060] Step 3: Apply a specific volume (determined based on performance design) of liquid metal to the surface of the nano-metal bonding layer under oxygen-free conditions to form an ultrathin liquid metal sealing layer;

[0061] Step 4: Cover and surround the ultrathin liquid metal sealing layer with a second polymer layer (if the second polymer layer has a nano-metal connecting layer deposited on it, then the side with the nano-metal connecting layer faces the liquid metal) to form an outer encapsulation structure; the edges of the first polymer layer and the second polymer layer can be sealed and connected by means of thermoforming, adhesive layer bonding, chemical cross-linking bonding or interpenetrating network structure, etc.

[0062] The method of coating an ultrathin liquid metal sealing layer onto a first polymer layer and / or a second polymer layer having a nano-metal bonding layer includes the following steps:

[0063] S1.1: In an oxygen-free environment, liquid metal is coated onto one side of the first polymer and / or second polymer layer having a nano-metal bonding layer to obtain a dense liquid metal sealing layer;

[0064] S1.2: Weigh and calculate the mass of the liquid metal sealing layer obtained in S1.1. Based on the performance design, remove excess liquid metal or add more liquid metal to achieve a liquid metal sealing layer density of approximately 0.013 g / cm³. 2 An ultrathin liquid metal sealing layer is obtained. In other embodiments, the surface density of the liquid metal sealing layer can be 0.006-0.030 g / cm³. 2 Adjustments can be made within a certain range, depending on the specific performance design requirements.

[0065] Example 1

[0066] like Figure 1As shown, a micropump heat dissipation structure using liquid metal encapsulation (encapsulated using the composite encapsulation structure of this solution) sequentially includes a first polymer layer 1, a nano-metal connecting layer 2, an ultrathin liquid metal sealing layer 3, a second polymer layer 4, and an object to be encapsulated 5 (in this embodiment, a liquid microchannel of a commercial flexible micropump radiator); the object to be encapsulated 5 is encapsulated by the first polymer layer 1 (forming an inner encapsulation structure); the side of the first polymer layer 1 facing the ultrathin liquid metal sealing layer 3 (the side facing away from the object to be encapsulated 5, i.e., the outer surface) has a nano-metal connecting layer 2; the ultrathin liquid metal sealing layer 3 is located between the nano-metal connecting layer 2 and the second polymer layer 4.

[0067] Optionally, in other embodiments, the nano-metal bonding layer 2 is deposited on the surface of the first polymer layer 1 and / or the second polymer layer 4, so that at least one side of the ultrathin liquid metal sealing layer 3 directly contacts the nano-metal bonding layer 2. In various scenarios, especially in dynamic environments with external forces, the nano-metal bonding layer 2 can provide adhesion and fixation for the liquid metal, ensuring the density of the liquid metal on the polymer layer and effectively playing a barrier role.

[0068] The metal element in the nano-metal bonding layer 2 is selected from gold, silver, copper, indium, etc. The thickness of the nano-metal bonding layer 2 is 20-200 nm, preferably 80 nm, and more preferably 50 nm. Specifically, the nano-metal bonding layer 2 is deposited using thin film deposition methods such as thermal evaporation, physical vapor deposition, chemical vapor deposition, magnetron sputtering, and electrochemical deposition. Preferably, the nano-metal bonding layer 2 is gold or silver, and more preferably, silver is used.

[0069] The liquid metal in the ultrathin liquid metal sealing layer 3 is selected from gallium-based liquid metals, indium-based liquid metals, and bismuth-based liquid metals, with a thickness between 10-50 μm. Specifically, the liquid metal can be selected from the following materials: metallic gallium, gallium-indium alloys, gallium-indium-tin alloys, gallium-silver alloys, gallium-aluminum alloys, gallium-zinc-gold alloys, gallium-indium-tin-zinc alloys, other gallium-based liquid metals, as well as indium-tin alloys, indium-bismuth alloys, bismuth-lead-tin-cadmium alloys, indium-tin-bismuth alloys, bismuth-lead-tin-cadmium-indium alloys, etc. The base metal content is above 70 wt%. Preferably, the liquid metal is a eutectic gallium-indium alloy (EGaIn), with a gallium content of approximately 75% and an indium content of approximately 25%.

[0070] The thicknesses of the first polymer layer 1 and the second polymer layer 4 are each in the range of 0.001-5 mm. The specific thicknesses of the first polymer layer 1 and the second polymer layer 4 can be selected and adjusted according to the actual packaging shape, size, and application environment. The first polymer layer 1 and the second polymer layer 4 are made of flexible organic polymer materials, which can be selected from thermoplastic flexible organic polymers, thermosetting flexible organic polymers, and combinations thereof. Specifically, the first polymer layer 1 and the second polymer layer 4 can be selected from thermoplastic flexible organic polymers (such as polyethylene terephthalate (PET)), thermosetting organic polymers (such as polydimethylsiloxane (PDMS)) or other flexible materials.

[0071] The method for preparing the composite encapsulation structure (microchannel encapsulation method) in this embodiment specifically includes the following steps:

[0072] Step 1: A gold nanofiber bonding layer with a thickness of approximately 50 nm is deposited on the surface of the first polymer layer facing away from the microchannel to be encapsulated using a thermal evaporation method.

[0073] Step 2: Surround and seal the liquid microchannels of the commercial flexible micropump radiator with the first polymer layer to form an inner encapsulation structure; wherein, the polymer used for the first polymer layer is PET with a thickness of 0.025mm;

[0074] Step 3: In an argon-filled glove box, an ultrathin liquid metal sealing layer (eutectic gallium-indium alloy) is coated onto the nano-metal bonding layer (gold). The amount of liquid metal used per unit area is approximately 0.013 g / cm³. 2 ;

[0075] Step 4: Surround and seal the ultrathin liquid nano-metal sealing layer with a second polymer layer and heat-press (together with the first polymer layer) to obtain the outer encapsulation structure. The polymer used in the second polymer layer is PET, with a thickness of 0.050 mm.

[0076] Accordingly, the structure of the resulting package includes the following components:

[0077] Inner encapsulation structure: formed by a first polymer layer surrounding and sealing the object to be encapsulated; wherein the first polymer layer is a PET layer with a thickness of 0.025 mm;

[0078] Outer packaging structure: formed by a second polymer layer surrounding and sealing an ultra-thin liquid metal sealing layer; wherein, the second polymer layer is a PET outer layer with a thickness of 0.050 mm;

[0079] The intermediate layer structure consists of a gold interconnect layer with a thickness of nanometers and a liquid metal eutectic gallium indium alloy layer with a thickness of micrometers.

[0080] The first polymer layer has a nanometer-thick gold interconnect layer on the side facing the eutectic gallium indium alloy layer. The eutectic gallium indium alloy layer is located between the outer encapsulation structure and the nanometer-thick gold interconnect layer. The thickness of the nanometer-thick gold interconnect layer is approximately 50 nm, and the amount of liquid metal eutectic gallium indium alloy per unit area is approximately 0.013 g / cm³. 2 .

[0081] Example 2

[0082] The main difference between this embodiment and Embodiment 1 is that the thicknesses of the first polymer layer and the second polymer layer are different, while the amount of liquid metal per unit area is kept the same. Specifically, in the package of Embodiment 2, the thickness of the first polymer layer is 0.2 mm, and the thickness of the second polymer layer is 0.1 mm.

[0083] Example 3

[0084] The main difference between this embodiment and Embodiment 1 is that the deposition method of the nano-metal interconnect layer of the package is different. Specifically, in the package of Embodiment 3, the nano-metal interconnect layer is deposited by magnetron sputtering.

[0085] Example 4

[0086] The main difference between this embodiment and embodiment 1 is that the thickness of the nano-metal interconnect layer in the package is different. Specifically, in the package of embodiment 4, the thickness of the nano-metal interconnect layer is 80nm.

[0087] Example 5

[0088] The main difference between this embodiment and embodiment 4 is that the type of nano-metal connecting layer of the package is different. Specifically, in the package of embodiment 5, the nano-metal connecting layer can be replaced with silver, copper or indium.

[0089] Example 6

[0090] The main difference between this embodiment and Embodiment 1 lies in the amount of liquid metal used per unit area in the encapsulation, resulting in a greater average thickness of the liquid metal sealing layer in Embodiment 6 compared to Embodiment 1. Specifically, in the encapsulation method of Embodiment 6, step three involves coating the nano-metal bonding layer with liquid metal in an argon glove box, with a liquid metal usage of 0.025 g / cm³. 2 .

[0091] Example 7

[0092] The main difference between this embodiment and Embodiment 1 is that the liquid metal encapsulation environment of the package is different. Liquid metal can be coated on the nano-metal connecting layer in a hydrochloric acid volatile atmosphere to eliminate the influence of the liquid metal oxide layer.

[0093] Example 8

[0094] The main difference between this embodiment and Embodiment 1 is that a nano-thickness gold interconnect layer is deposited on both the side of the first polymer layer facing the eutectic gallium indium alloy layer and the side of the second polymer layer facing the eutectic gallium indium alloy layer.

[0095] Comparative Example 1

[0096] The main difference between the packaged component of this comparative example and Example 1 is that it does not use liquid metal (ultra-thin liquid metal sealing layer) and gold interconnect layer (nano-metal interconnect layer). The fabrication method of the composite packaged structure of this comparative example (microfluidic encapsulation method) specifically includes the following steps:

[0097] Step 1: Surround and seal the liquid microchannels of the commercial flexible micropump radiator with a first polymer layer to form an inner encapsulation structure; wherein, the polymer used for the first polymer layer is PET with a thickness of 0.025mm;

[0098] Step 2: Surround and seal the outer packaging structure with a second polymer layer and thermo-press (together with the first polymer layer). The second polymer layer is made of PET and has a thickness of 0.050 mm.

[0099] Correspondingly, the package of Comparative Example 1 includes the following structural components:

[0100] Inner encapsulation structure: formed by a first polymer layer surrounding and sealing the object to be encapsulated; wherein the first polymer layer is a PET layer with a thickness of 0.025 mm;

[0101] Outer encapsulation structure: formed by a second polymer layer surrounding and sealing the first polymer layer; wherein the second polymer layer is a PET outer layer with a thickness of 0.050 mm.

[0102] Comparative Example 2

[0103] The main difference between the packaged component of this comparative example and Example 1 is that it does not use a gold interconnect layer (nanometallic interconnect layer 2). The fabrication method of the composite packaged structure of this comparative example (microfluidic channel packaging method) specifically includes the following steps:

[0104] Step 1: Surround and seal the liquid microchannels of the commercial flexible micropump radiator with a first polymer layer to form an inner encapsulation structure; wherein, the polymer used for the first polymer layer is PET with a thickness of 0.025mm;

[0105] Step 2: In an argon-filled glove box, an ultrathin liquid metal sealing layer (eutectic gallium-indium alloy) is coated onto the first polymer layer. The amount of liquid metal used per unit area is approximately 0.013 g / cm³. 2 ;

[0106] Step 3: Surround and seal the ultrathin liquid nano-metal sealing layer with a second polymer layer and heat-press (together with the first polymer layer) to obtain the outer encapsulation structure. The second polymer layer uses PET as the polymer and has a thickness of 0.050 mm.

[0107] Accordingly, the structure of the package obtained from Comparative Example 2 includes the following components:

[0108] Inner encapsulation structure: formed by a first polymer layer surrounding and sealing the object to be encapsulated; wherein the first polymer layer is a PET layer with a thickness of 0.025 mm;

[0109] Outer packaging structure: formed by a second polymer layer surrounding and sealing an ultra-thin liquid metal sealing layer; wherein, the second polymer layer is a PET outer layer with a thickness of 0.050 mm;

[0110] The intermediate layer structure consists of a micrometer-thick liquid metal eutectic gallium indium alloy layer.

[0111] Performance testing and results:

[0112] Working fluid leakage test:

[0113] The sealing performance of liquid metal encapsulation systems can be characterized by monitoring the mass change of a commercial flexible micropump heat dissipation structure filled with working fluid (deionized water).

[0114] In Example 1, 150 ± 1 mg of water was injected into the microchannel of the micropump heat dissipation device encapsulated with liquid metal, and in Comparative Example 1, the micropump heat dissipation device encapsulated with liquid metal was heat-sealed at both ends (inlet and outlet). After filling, the commercial flexible micropump heat dissipation structure encapsulated with liquid metal was placed on an analytical balance, which was placed in a glove box filled with argon gas (water content < 0.01 ppm). The mass change of the encapsulated component was weighed and monitored every 24 hours.

[0115] like Figure 2 As shown, the "Conventional Liquid Metal Encapsulation" curve represents the mass change of the liquid metal-encapsulated micropump heat dissipation structure (Example 1) in its original state, while the "Flexible Liquid Metal Encapsulation" curve represents the mass change of the liquid metal-encapsulated micropump heat dissipation structure (Example 1) in a 60° bent state. During the 96-hour measurement period, the mass of the liquid metal-encapsulated micropump heat dissipation structure remained essentially unchanged in both the original and 60° bent states (mass fluctuation on analytical balance weighing was less than 0.5 mg), demonstrating its good sealing performance under both normal and bent conditions. Based on the results of Example 1, the sealing performance of the liquid metal-encapsulated systems in Examples 2-8 is basically consistent with that of Example 1, as the barrier performance of the samples is mainly manifested through the liquid metal layer, which will not be elaborated further here.

[0116] In contrast, the curve for "PET-based conventional encapsulation" is the mass change curve of the micropump heat dissipation structure in Comparative Example 1, which only has PET encapsulation, in its original state. Comparative Example 1, without the introduction of the ultrathin liquid metal sealing layer 3 and the gold connecting layer, exhibits significant mass loss under conventional sealing conditions, with an average daily mass loss of approximately 11 mg. This is mainly due to the insufficient barrier effect of the single polymer layer, which is insufficient to meet practical application requirements. Furthermore, in Comparative Example 2, the liquid metal in the encapsulated structure flows and detaches at a 60° bend, causing encapsulation failure at the bend point. In contrast, in Example 1, the liquid metal remains tightly adhered to the metal connecting layer at a 60° bend, and testing shows virtually no mass loss in the sealed component. Therefore, the encapsulation structure constructed in this scheme can effectively address the leakage problem of working fluid under static and bending conditions. In addition, comparative tests also reflect that this invention, with the combined design of the ultrathin liquid metal sealing layer and the metal connecting layer, achieves synergistic optimization of the encapsulation's flexibility, lightweight, and high sealing performance, demonstrating significant technological advancement and industrial application value.

[0117] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An ultrathin liquid metal-based composite encapsulation structure for flexible micropump heat dissipation devices, used to encapsulate an object to be encapsulated (5), characterized in that, The composite packaging structure includes a first polymer layer (1), a nano-metal connecting layer (2), an ultrathin liquid metal sealing layer (3), and a second polymer layer (4). The first polymer layer (1) covers the outside of the object to be packaged (5) to form an inner packaging structure; The ultrathin liquid metal sealing layer (3) is coated on the nano-metal connecting layer (2), the nano-metal connecting layer (2) is located between the first polymer layer (1) and the second polymer layer (4), and the ultrathin liquid metal sealing layer (3) and the nano-metal connecting layer (2) form an intermediate layer structure; the thickness of the ultrathin liquid metal sealing layer (3) is between 10-50 μm; The second polymer layer (4) is connected to the edge of the first polymer layer (1) to form an outer encapsulation structure.

2. The ultrathin liquid metal-based composite packaging structure for a flexible micropump heat dissipation device according to claim 1, characterized in that, The liquid metal in the ultrathin liquid metal sealing layer (3) is selected from gallium-based, indium-based and bismuth-based liquid metals.

3. The ultrathin liquid metal-based composite packaging structure for a flexible micropump heat dissipation device according to claim 1, characterized in that, The nanometals in the nanometal bonding layer (2) are selected from gold, silver, copper and indium.

4. The ultrathin liquid metal-based composite packaging structure for a flexible micropump heat dissipation device according to claim 1, characterized in that, The thickness of the nano-metal interconnect layer (2) is between 20-200 nm.

5. The ultrathin liquid metal-based composite packaging structure for a flexible micropump heat dissipation device according to claim 1, characterized in that, The first polymer layer (1) and the second polymer layer (4) are flexible organic polymer materials; The flexible organic polymer material is a thermoplastic flexible organic polymer and a thermosetting flexible organic polymer.

6. The ultrathin liquid metal-based composite packaging structure for a flexible micropump heat dissipation device according to claim 1, characterized in that, The thickness of the first polymer layer (1) is 0.001-5 mm, and the thickness of the second polymer layer (4) is 0.001-5 mm.

7. The ultrathin liquid metal-based composite packaging structure for a flexible micropump heat dissipation device according to claim 1, characterized in that, The second polymer layer (4) is connected to the first polymer layer (1) at the edge by thermo-press bonding, adhesive bonding, chemical cross-linking bonding or interpenetrating network structure.

8. A method for ultrathin liquid metal-based composite packaging for flexible micropump heat dissipation devices, characterized in that, Includes the following steps: Step 1: Deposit a nano-metal interconnect layer (2) on the surface of the first polymer layer (1) and / or the second polymer layer (4); Step 2: Surround and seal the object to be packaged (5) with the first polymer layer (1); Step 3: Apply liquid metal onto the nano-metal bonding layer (2) under oxygen-free conditions to form an ultra-thin liquid metal sealing layer (3). Step 4: Surround the ultrathin liquid metal sealing layer (3) with the second polymer layer (4) and connect the first polymer layer (1) with the second polymer layer (4) to obtain the composite encapsulation structure as described in any one of claims 1-7.

9. The ultrathin liquid metal-based composite packaging method for a flexible micropump heat dissipation device according to claim 8, characterized in that, The deposition method is a thin film deposition method, including thermal evaporation, physical vapor deposition, chemical vapor deposition, magnetron sputtering, and electrochemical deposition.

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