Two-phase flow vacuum seal structure

Abstract

The utility model discloses two phase flow vacuum sealing structure in two phase flow heat dissipation and high air tightness packaging field, including two layer base material layer and the sealing structure layer of setting in the peripheral edge position between base material layer layer, the sealing structure layer central position is located between two layer base material layers and is provided with capillary structure layer, is provided with the barrier layer between capillary structure layer with sealing structure layer. The utility model provides the sealing edge glue type and the two kinds of sealing structure selection of weldable base material type, can according to different application scene and material characteristics, flexible selection suitable sealing mode, has improved the process adaptability significantly. Whether it is for the production scene needing quick solidification, convenient operation, or for the product of sensitive to sealing glue, the requirement of no glue sealing can provide effective sealing solution.

Description

Technical Field

[0001] This utility model relates to the field of two-phase flow heat dissipation and high-sealing packaging, specifically a two-phase flow vacuum sealing structure. Background Technology

[0002] With the increasing trend towards thinner, lighter, and higher-performance electronic devices, the requirements for heat dissipation and sealing technologies are becoming increasingly stringent. Traditional two-phase flow heat dissipation modules often employ metallic materials and welded together to achieve a sealed cavity. However, with the rise of flexible electronics and non-metallic heat dissipation structures, this traditional approach faces numerous challenges. Welding is difficult to implement in flexible electronics or non-metallic heat dissipation structures because the high temperatures during the welding process can damage the structure and properties of the flexible or non-metallic materials.

[0003] When applications demand long-term airtightness and low moisture vapor transmission rate (WVTR), commonly used plastic substrates (such as PET and PC) have weak barrier properties and cannot meet the requirements of vacuum heat dissipation chambers on their own. While multi-layered protective and sealing structures can be used to address this issue, current technology lacks a comprehensive solution that simultaneously achieves structural adjustability, high barrier properties, low gas release, and high capillary reflux efficiency. This limits the performance, stability, and lifespan of products in practical applications, failing to meet market demands for high-quality electronic devices.

[0004] Therefore, those skilled in the art have provided a two-phase flow vacuum sealing structure to solve the problems mentioned in the background art. Utility Model Content

[0005] The purpose of this invention is to provide a two-phase flow vacuum sealing structure to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A two-phase flow vacuum sealing structure includes two substrate layers and a sealing structure layer disposed at the outer edge of the substrate layers. A capillary structure layer is disposed at the center of the sealing structure layer between the two substrate layers, and a barrier layer is disposed between the capillary structure layer and the sealing structure layer.

[0008] The substrate layer is made of plastic or glass and has a thickness of 0.06-0.1 mm.

[0009] The sealing structure layer is divided into two categories: the first type (Type 1) is the edge sealing adhesive type, and the second type (Type 2) is the weldable substrate type;

[0010] The barrier layer is an Al2O3 / SiO2 multilayer structure deposited using ALD or PECVD processes, with a single layer thickness of 10-30 nm and a total of 5 layers. This Al2O3 / SiO2 multilayer structure achieves a moisture vapor transmission rate (WVTR) of up to 10. -6 g / m 2 / day;

[0011] The capillary layer is composed of Nylon, LCP, Polyester or metal fibers, and has a dual-density structure, with one side having a low density and the other side having a high density, or a structure that gradually decreases in density from high density to low density.

[0012] Furthermore, in the sealing structure layer, the edge sealing adhesive is suitable for both plastic and glass materials, and uses UV adhesive or thermosetting adhesive, with a moisture transmittance (WVTR) < 0.1 g / m². 2 / day, with low gas release and low permeability characteristics; the weldable substrate type is suitable for plastic materials, and the sealing structure layer is made of the same plastic material as the substrate layer, and the seal is achieved by ultrasonic welding.

[0013] Furthermore, the edge sealing adhesive is a UV adhesive or a thermosetting adhesive, wherein the curing conditions for the thermosetting adhesive are a temperature of 80-120℃ and a curing time of 10-40 minutes.

[0014] Furthermore, in the preparation process of the barrier layer, if PECVD process is used, the process parameters are temperature 120±5℃, pressure 0.5Torr, and deposition rate 10nm / min.

[0015] Furthermore, the dual-density structure of the capillary layer is made by weaving or sintering processes, which realizes the retention of liquid in the high-density region and the vapor flow space in the low-density region based on capillary phenomenon, and satisfies CVCM (Collected Volatile Condensable Materials) ≤ 0.1% and TML (Total Mass Loss) < 1%.

[0016] Furthermore, the plastic material is selected from one or more of PC, PET, PI, acrylic, PP, and PE.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1. This utility model adopts a multi-sealing compatibility design to improve process adaptability;

[0019] 2. This invention employs a multi-layer barrier + nano-deposition structure to achieve extremely low WVTR and OTR;

[0020] 3. In this invention, the capillary structure supports efficient reflux and heat dissipation circulation of two-phase liquids;

[0021] 4. The packaging of this utility model has the advantages of flexibility, high airtightness and low cost, and is suitable for different terminal structure applications. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model.

[0023] In the diagram: 1. Substrate layer; 2. Sealing structure layer; 3. Barrier layer; 4. Capillary structure layer. Detailed Implementation

[0024] Please see Figure 1 A two-phase flow vacuum sealing structure includes two substrate layers 1 and a sealing structure layer 2 disposed at the outer edge of the substrate layer 1. A capillary structure layer 4 is disposed at the center of the sealing structure layer 2 between the two substrate layers 1, and a barrier layer 3 is disposed between the capillary structure layer 4 and the sealing structure layer 2.

[0025] The substrate layer 1 is made of plastic or glass and has a thickness of 0.06-0.1 mm (preferably 0.08 mm).

[0026] The sealing structure layer 2 is divided into two types: the first type (Type 1) is the edge sealing adhesive type, and the second type (Type 2) is the weldable substrate type;

[0027] Barrier layer 3 is an Al2O3 / SiO2 multilayer structure deposited using ALD or PECVD processes, with a single layer thickness of 10-30 nm and a total of 5 layers. This Al2O3 / SiO2 multilayer structure achieves a moisture vapor transmission rate (WVTR) of up to 10. -6 g / m 2 / day;

[0028] The capillary layer 4 is composed of Nylon, LCP, Polyester or metal fibers, and has a dual-density structure, with one side having a low density and the other side having a high density, or a high-density gradient to low-density structure.

[0029] In the sealing structure layer 2, the edge sealing adhesive is suitable for both plastic and glass materials, and uses UV adhesive or thermosetting adhesive with a moisture transmittance (WVTR) of <0.1 g / m. 2 / day, with low gas release and low permeability characteristics; the weldable substrate type is suitable for plastic materials, and the sealing structure layer 2 is made of the same plastic material as the substrate layer 1, and the seal is achieved by ultrasonic welding.

[0030] The edge sealing adhesive can be either UV adhesive or thermosetting adhesive. Thermosetting adhesives require a curing temperature of 80-120℃ and a curing time of 10-40 minutes. For example, 3M DP125 adhesive requires a curing temperature of 80℃ and a curing time of 40 minutes.

[0031] In the preparation process of barrier layer 3, if PECVD process (taking SiO2 as an example) is used, the process parameters are temperature 120±5℃, pressure 0.5Torr, and deposition rate 10nm / min.

[0032] PECVD is a technique for achieving chemical vapor deposition at relatively low temperatures using plasma assistance. It utilizes radio frequency (RF) or microwave power to generate plasma, which ionizes reactive gases to form active groups. These active groups then undergo a chemical reaction on the substrate surface and are deposited as a thin film.

[0033] Specific parameters:

[0034] Temperature: 120±5℃;

[0035] Pressure: 0.5 Torr (approximately 66.7 Pa);

[0036] Deposition rate: 10 nm / min (taking SiO2 as an example);

[0037] Reacting gases: Typically, silane (SiH4) and oxygen (O2) or nitrogen (N2) are used;

[0038] Power supply frequency: Typically 13.56MHz radio frequency power supply.

[0039] Process flow:

[0040] Place the substrate into the vacuum reaction chamber;

[0041] Evacuate to base pressure;

[0042] Introduce the reaction gas and adjust it to the working pressure (0.5 Torr);

[0043] Applying radio frequency power generates plasma;

[0044] Controlling the deposition time to obtain the desired film thickness;

[0045] After deposition is complete, turn off the power and gas, and remove the sample.

[0046] Advantages:

[0047] Low-temperature processing (120℃) is suitable for heat-sensitive substrates;

[0048] Fast deposition rate (10 nm / min);

[0049] The film has high density and strong adhesion;

[0050] It can be used to prepare various dielectric thin films such as SiO2 and SiNx.

[0051] Among them, the dual-density structure of the capillary layer 4 is made by weaving or sintering process. Based on the capillary phenomenon, the liquid is retained in the high-density area and the low-density area is the space for vapor flow. It also satisfies CVCM (Collected Volatile Condensable Materials) ≤ 0.1% and TML (Total Mass Loss) < 1%.

[0052] The plastic material is selected from one or more of PC, PET, PI, acrylic, PP, and PE.

[0053] A method for manufacturing a two-phase flow vacuum sealing structure includes the following steps:

[0054] S1. Prepare substrate layer 1. Select appropriate plastic or glass materials according to design requirements and process them to a thickness of 0.06-0.1mm.

[0055] S2. For sealing structure layer 2, if it is an edge-sealing adhesive type, UV adhesive or thermosetting adhesive is applied to the corresponding substrate, and the thermosetting adhesive is cured according to the set curing conditions; if it is a weldable substrate type, the same plastic as the substrate layer 1 is connected to the substrate layer 1 by ultrasonic welding process.

[0056] S3. Barrier layer 3 is prepared on the inner or outer surface of the substrate layer using ALD or PECVD process, and the thickness of a single layer of Al2O3 / SiO2 multilayer structure is controlled to be 10-30nm, with a total of 5 layers.

[0057] S4. A dual-density capillary structure layer 4 is prepared using Nylon, LCP, Polyester, or metal fibers through weaving or sintering processes, and then the capillary structure layer 4 is installed in a suitable position inside the sealing structure.

[0058] Atomic Layer Deposition (ALD) is a thin film deposition technique based on self-limited surface reactions. By alternately introducing different precursor gases, a self-limited chemical reaction occurs on the substrate surface, and thin films are grown layer by layer.

[0059] Specific parameters:

[0060] Deposition material: Al2O3 / SiO2 multilayer structure;

[0061] Single-layer thickness: 10-30nm;

[0062] Total number of floors: 5;

[0063] Temperature: typically 150-300℃ (not specified in the patent, but generally lower than the PECVD temperature).

[0064] Process flow:

[0065] The substrate is placed in the reaction chamber and heated;

[0066] The first precursor (such as trimethylaluminum TMA) is introduced, and a monolayer adsorption is formed on the surface;

[0067] Excess precursors are purged with an inert gas (such as N2);

[0068] A second precursor (such as H2O or O3) is introduced, which reacts with the adsorption layer to form oxides;

[0069] Purge again with inert gas;

[0070] Repeat the cycle until the desired thickness is achieved.

[0071] Preparation of Al2O3 / SiO2 multilayer structure:

[0072] First, deposit an Al2O3 layer (using TMA and H2O / O3);

[0073] Redeposit a SiO2 layer (using silane precursor and oxygen);

[0074] Five layers were deposited alternately, with a total thickness of 50-150 nm.

[0075] Advantages:

[0076] Atomic-level thickness control ensures excellent uniformity;

[0077] Excellent step coverage, suitable for complex structures;

[0078] The thin film is dense and has few defects;

[0079] Extremely low WVTR (10) can be achieved -6 g / m 2 / day).

[0080] In step S3, when preparing the barrier layer 3, if the PECVD process is used, taking SiO2 as an example, the temperature needs to be controlled at 120±5℃, the pressure at 0.5Torr, and the deposition rate at 10nm / min.

[0081] In step S2, when curing the UV adhesive or thermosetting adhesive of the edge sealing type, taking 3M DP125 adhesive as an example, the curing conditions are a temperature of 80°C and a curing time of 40 minutes.

[0082] An application of a two-phase flow vacuum sealing structure, which is used in one or more thermal management and packaging systems for mobile terminals, wearable devices, and high-density electronic products.

[0083] Example 1

[0084] Application in foldable phones: PET is selected as the substrate layer 1, utilizing its excellent flexibility and optical properties to meet the substrate requirements of foldable phones. The sealing structure layer uses a weldable substrate, with identical PET materials sealed via ultrasonic welding to ensure reliable sealing during folding. The barrier layer 3 uses an ALD process to deposit an Al2O3 / SiO2 multilayer structure, prepared with a single layer thickness of 10-30nm and a total of 5 layers, effectively blocking the influence of external moisture and oxygen on the internal heat dissipation structure. The capillary structure layer 4 uses a dual-density capillary structure composed of Nylon fibers, manufactured through a weaving process, and installed inside the heat dissipation cavity to achieve efficient two-phase flow heat dissipation circulation. After 100,000 folding tests, the WVTR retention rate is >95%. In environmental testing from -20 to 80℃, the WVTR retention rate is also >95%, and no delamination occurs at a bending radius of 3mm, demonstrating the stability and reliability of this sealing structure in foldable phone applications.

[0085] Example 2

[0086] Applications in flexible sensors: For flexible sensors, PI is chosen as the substrate layer 1 due to its high heat resistance and chemical stability, enabling it to meet the operational requirements of sensors in complex environments. The sealing structure layer uses an edge-sealing adhesive, sealed with UV-cured glue, for example, selecting an adhesive that meets the requirement of WVTR < 0.1 g / m³. 2 The standard UV adhesive forms a stable sealing layer under UV curing. Barrier layer 3 is formed using PECVD at 120±5℃, 0.5 Torr pressure, and a deposition rate of 10 nm / min (taking SiO2 as an example) to create a nanostructured barrier layer. Capillary layer 4 is a dual-density capillary structure composed of metal fibers, fabricated through a sintering process, providing an efficient liquid return channel for two-phase flow heat dissipation. In practical applications, this sealing structure effectively protects the internal components of the flexible sensor, ensuring its stable operation under various environments.

[0087] Example 3

[0088] Application in High-Density Server Chip Heat Dissipation: Considering the high requirements for heat dissipation and sealing of high-density server chips, PC was selected as the substrate layer 1, leveraging its excellent dimensional stability and electrical properties. The sealing structure layer uses a solderable substrate, achieving high airtightness through ultrasonic welding. The barrier layer 3 employs an Al2O3 / SiO2 multilayer structure deposited by ALD, with strict control over the thickness of each layer and the total number of layers to achieve optimal barrier effect. The capillary structure layer 4 uses a dual-density capillary structure composed of LCP fibers, manufactured through a weaving process to optimize the liquid return path and improve heat dissipation efficiency. In actual testing, this sealing structure effectively reduced the chip's operating temperature, improving the server's operational stability and reliability.

[0089] Example 4

[0090] In applications of transparent display devices, substrate layer 1 is made of ultra-thin soda-lime glass or high borosilicate glass, with a thickness of 0.1-0.03 mm (prepared through chemical thinning or float glass processes), possessing high light transmittance (≥90%), high temperature resistance (softening point > 500℃), and a low coefficient of thermal expansion (3.3 × 10⁻⁶). -6 / K); Sealing structure layer 2: Select edge sealing adhesive type, using low melting point glass powder (such as PbO-B2O3-ZnO system) or UV curable optical adhesive (such as NOA81), after curing WVTR < 0.05g / m 2 / day, meeting the dual requirements of airtightness and light transmittance for transparent display devices; Barrier layer 3: An Al2O3 / SiO2 multilayer barrier layer is deposited on the inner surface of the glass substrate using the ALD process; Capillary structure layer 4: A dual-density structure is woven from transparent metal oxide fibers (such as SnO2-In2O3 composite fibers), with the high-density area (porosity 30%) used for liquid phase reflux and the low-density area (porosity 70%) serving as a vapor channel, achieving a light transmittance >80%. Performance test results are shown in the table below:

[0091] Water tightness (WVTR) 38℃ / 90%RH, ASTM F1249 <![CDATA[2.1×10 -6 g / m 2 / day]]> Light transmittance Wavelength 550nm, ASTM D1003 Overall structure >85% Thermal cycling stability -40℃~85℃, 500 times No stratification, WVTR variation <3% Bending performance (flexible version) Bending radius 10mm, 10,000 cycles The barrier layer is crack-free, and the light transmittance remains >82%.

[0092] It boasts the following advantages: High transparency and airtightness: solving the problem of reduced light transmittance in display devices caused by traditional metal sealing. High temperature resistance: The glass substrate + low-melting-point glass powder sealing can withstand the localized high temperatures (>150℃) of the display backlight module. Flexible adaptation: The chemically strengthened glass substrate can be applied to curved screens or rollable display devices.

[0093] In actual production, both the edge-sealing adhesive structure and the weldable substrate structure have passed reliability verification. The entire technical solution performed well in the pilot-scale stage and has the potential for further large-scale production. During production, the parameters and preparation processes of each layer of the sealing structure can be flexibly adjusted according to different product requirements and application scenarios to achieve the best performance-cost balance.

[0094] Analysis of the test results of Examples 1-4 shows that:

[0095] Multiple sealing compatibility design: By offering two sealing structure options—edge-sealing adhesive type and weldable substrate type—the appropriate sealing method can be flexibly selected according to different application scenarios and material characteristics, significantly improving process adaptability. Whether for production scenarios requiring rapid curing and ease of handling, or for products sensitive to sealant and requiring glue-free sealing, it provides an effective sealing solution.

[0096] Achieving extremely low WVTR and OTR: A combination of multi-layer barrier and nano-deposition structure is employed. The nanostructure of the barrier layer and the sealing layer work synergistically to significantly reduce moisture vapor transmission rate (WVTR) and oxygen transmission rate (OTR). Testing showed that under conditions of 25℃ / 60% RH, the WVTR of the edge-sealing adhesive structure was 3.2 × 10⁻⁶. -6 g / m 2 / day, OTR is 5.1×10 -4 cc / m 2 / day; the WVTR of the weldable substrate type structure is 2.8×10 -6 g / m 2 / day, OTR is 4.7×10 -4 cc / m 2 / day effectively protects internal components from external environmental corrosion, improving product reliability and lifespan.

[0097] High-efficiency heat dissipation circulation: The dual-density capillary structure of capillary layer 4 provides an efficient reflux channel for the two-phase liquid, ensuring that after the liquid evaporates due to heat, it can smoothly return to the heat source for reheating through capillary action, maintaining a stable liquid circulation and achieving efficient heat dissipation. This helps improve the heat dissipation efficiency of electronic equipment and ensures the stability and performance of the equipment under high load operation.

[0098] Adaptable to various terminal structures: The dual-density capillary structure of capillary layer 4 provides an efficient reflux channel for two-phase liquids, ensuring that after the liquid evaporates due to heat, it can smoothly return to the heat source for reheating through capillary action, maintaining stable liquid circulation and achieving efficient heat dissipation. This helps improve the heat dissipation efficiency of electronic devices and ensures the stability and performance of the equipment under high load operation.

[0099] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A two-phase flow vacuum seal structure, characterized by: It includes a two-layer substrate layer (1) and a sealing structure layer (2) disposed at the outer edge of the substrate layer (1). A capillary structure layer (4) is disposed at the center of the sealing structure layer (2) between the two substrate layers (1). A barrier layer (3) is disposed between the capillary structure layer (4) and the sealing structure layer (2). The substrate layer (1) is made of plastic or glass material with a thickness of 0.06-0.1 mm; The sealing structure layer (2) is divided into two categories: the first category is the edge sealing adhesive type, and the second category is the weldable substrate type; The barrier layer (3) is an Al2O3 / SiO2 multilayer structure deposited by ALD or PECVD process, with a single layer thickness of 10-30 nm and a total of 5 layers. Through this Al2O3 / SiO2 multilayer structure, the moisture permeability (WVTR) can reach 10⁻. 6 g / m² / day; The capillary layer (4) is composed of Nylon, LCP, Polyester or metal fibers, and has a dual-density structure with low density on one side and high density on the other side, or a high-density gradient to low-density structure.

2. The two-phase flow vacuum sealing structure according to claim 1, characterized in that: In the sealing structure layer (2), the edge sealing adhesive type is suitable for plastic and glass materials. The edge sealing adhesive type uses UV adhesive or thermosetting adhesive, and the moisture permeability WVTR < 0.1g / m² / day, which has low gas release and low permeability characteristics. The weldable substrate type is suitable for plastic materials. The sealing structure layer (2) uses the same plastic material as the substrate layer (1) and achieves sealing by ultrasonic welding.

3. The two-phase flow vacuum sealing structure according to claim 2, characterized in that: The edge sealing adhesive is either UV adhesive or thermosetting adhesive. The thermosetting adhesive is cured at a temperature of 80-120°C for 10-40 minutes.

4. The two-phase flow vacuum sealing structure according to claim 1, characterized in that: In the preparation process of the barrier layer (3), if the PECVD process is used, the process parameters are temperature 120±5°C, pressure 0.5Torr, and deposition rate 10nm / min.

5. The two-phase flow vacuum seal structure according to claim 1, characterized by: The dual-density structure of the capillary layer (4) is made by weaving or sintering process. Based on the capillary phenomenon, the liquid is retained in the high-density area and the low-density area is the space for vapor flow, and satisfies CVCM≤0.1% and TML<1%.

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