Liquid metal based method and apparatus for filling and sealing of high aspect ratio glass vias

Abstract

The application discloses a liquid metal-based large-aspect-ratio glass via filling and sealing method and device, and belongs to the field of electronic packaging. The method mainly comprises liquid metal filling large-aspect-ratio glass via (TGV) based on inkjet 3D printing, nano-silver ink curing and sealing, and filling and sealing device design. The nano-silver ink after photocuring is used to seal and fill the large-aspect-ratio TGV filled with liquid metal, which can effectively prevent the liquid metal from overflowing, and meanwhile, the device can realize accurate filling and reliable sealing of the large-aspect-ratio TGV array. The high electrical conductivity, low resistivity, high thermal conductivity and excellent fluidity of the liquid metal make the TGV interconnection structure have excellent filling quality, high-frequency electrical characteristics and heat dissipation performance, effectively solve the problems, such as the defects of easy generation of cavities and concaves in the traditional filling process, poor adhesion between the glass hole wall and the copper, and the difficulty of copper material in meeting the high-frequency and high-speed transmission demand of future radio frequency systems.

Description

Technical Field

[0001] This application belongs to the field of electronic packaging and is suitable for multilayer circuit interconnection of high-frequency and high-speed radio frequency components. Specifically, it relates to a method and apparatus for filling and sealing glass through-holes with large aspect ratio based on liquid metal. Background Technology

[0002] With the rapid development of aerospace, automotive electronics, and other fields, future radio frequency (RF) systems will be deployed at higher frequency bands to meet their demands for high performance, miniaturization, and diversification. Glass, due to its excellent high-frequency electrical properties, is increasingly being used in RF system packaging and RF components. Through-Glass Via (TGV) technology enables multi-layer electrical interconnection and is a core technology for achieving high-density packaging of RF systems. Filling is a crucial step in TGV technology; by filling the via with conductive material, current can be conducted from one end to the other, ensuring the electrical performance of the RF system and enhancing its mechanical stability. Chemical / electroplated copper is currently the most commonly used TGV filling method. However, these methods still face significant challenges in high aspect ratio TGV filling, mainly in the following aspects: (1) Voids and depressions are easily generated during the high aspect ratio TGV filling process, affecting the electrical and mechanical properties of the interconnect structure; (2) The adhesion between the glass hole wall and the metal material is poor, and delamination is easy to occur at the filling interface, which leads to the curling or even detachment of the filling layer; (3) Copper material is difficult to meet the requirements of high frequency and high speed of RF systems due to significant skin effect, poor dielectric constant and dielectric loss factor. Therefore, the development of new high aspect ratio TGV filling methods and devices is of great significance for promoting the miniaturization and diversification of high performance RF systems.

[0003] Liquid metals, such as gallium-based alloys, possess high conductivity and low resistivity, enabling more efficient current transmission, reducing signal transmission loss, improving the signal transmission quality and efficiency of RF components, reducing signal distortion and attenuation, and better meeting the demands of high-frequency, high-speed signal transmission. Simultaneously, liquid metals exhibit excellent fluidity, allowing for adaptive filling of small, complex shapes, and high aspect ratio TGV structures, ensuring uniform filling and tight interface contact, reducing contact resistance and signal reflection, and guaranteeing reliable electrical connections. By selecting different liquid metal compositions or alloy formulations, their physical properties (such as the coefficient of thermal expansion) can be adjusted to a certain extent, allowing for better matching with glass substrates and other packaging materials, thereby improving the stability and reliability of the entire packaging structure and reducing the risk of failure due to factors such as thermal mismatch. Furthermore, liquid metals have high thermal conductivity, effectively conducting away the heat generated by the chip, improving the heat dissipation performance of RF components, reducing chip operating temperature, and thus improving chip reliability and lifespan.

[0004] Based on the above analysis, liquid metal, with its excellent fluidity, electrical conductivity, and thermal conductivity, provides a new approach and solution for filling high-quality, high-performance, large aspect ratio TGVs. However, it is worth noting that because liquid metal itself is fluid, effective sealing of the liquid metal filling the TGV is necessary to prevent leakage. Summary of the Invention

[0005] The purpose of this application is to address the defects such as voids and depressions that are easily generated during the traditional chemical copper plating and electroplating copper filling process of large aspect ratio TGV, the poor adhesion between the glass hole wall and the metallic copper, and the difficulty of copper materials meeting the high-frequency and high-speed transmission requirements of future radio frequency systems. This application provides a method and apparatus for filling and sealing large aspect ratio glass through holes based on liquid metal.

[0006] The method described in this application mainly includes liquid metal filling of large aspect ratio glass through-holes based on inkjet 3D printing, curing and sealing with nano-silver ink, and the design of an integrated filling and sealing device. Compared with the complex process of traditional TGV filling methods, which require the deposition of a seed layer followed by electroplating, inkjet 3D printing can directly and precisely print the filling material into the TGV along a pre-set path using the nozzle tip. This not only simplifies the process but also enables precise filling of small-sized TGVs. Furthermore, inkjet 3D printing allows for the composite printing of multiple different materials, and nano-silver ink printing and photopolymerization are used to achieve the sealing of liquid metal in the TGV. To further ensure the adhesion and spread of the liquid metal on the inner wall of the TGV and improve the wettability of the hole wall, plasma bombardment of the TGV inner wall or laser processing of micro-nano structures on the TGV inner wall are used. In addition, the device described in this application can simultaneously achieve precise filling and reliable sealing of large aspect ratio TGV arrays.

[0007] The objective of this application is achieved through the following technical solution:

[0008] A method for filling and sealing large aspect ratio glass through-holes based on liquid metal includes the following steps:

[0009] Step 1: Prepare a PDMS substrate and a glass substrate with glass vias. Apply heat release tape tightly between the glass substrate and the PDMS substrate, and then place them in a heat sealer. The heat release tape melts to form a heat release tape sealing layer to bond the glass substrate and the PDMS substrate together.

[0010] Step 2: Fill the bottom of the glass through hole with nano-silver ink, and then turn on the near-infrared light source to cure the nano-silver ink by light to form a nano-silver sealing layer at the bottom of the glass through hole.

[0011] Step 3: Fill the glass through-hole with liquid metal;

[0012] Step 4: Fill the opening of the glass through hole with nano-silver ink and then turn on the near-infrared light source to cure the nano-silver ink by light to form a nano-silver sealing layer at the opening of the glass through hole.

[0013] Step 5: Heat the glass substrate and the PDMS substrate to separate them.

[0014] Furthermore, the X-axis, Y-axis, and Z-axis coarse adjustment motion stages are used to control the movement of the nano-silver ink multi-head module to fill or move away from the glass through-hole; the X-axis, Y-axis, and Z-axis coarse adjustment motion stages are also used to control the movement of the liquid metal multi-head module to fill or move away from the glass through-hole; the X-axis coarse adjustment motion stage and pneumatic device are used to control the movement of the near-infrared light source to the glass through-hole for photocuring or to move away from the glass through-hole; and the XYZ fine adjustment motion stages are used to control the precise alignment of the glass through-hole with the multi-head module.

[0015] Furthermore, the glass vias are arrays with a large aspect ratio, fabricated using a femtosecond laser-induced wet etching method, and micro / nano structures are fabricated on the inner wall of the TGV using a femtosecond laser, or by bombarding the inner wall of the TGV with plasma; the liquid metal multi-nozzle module and the nano-silver ink multi-nozzle module are based on inkjet 3D printing technology.

[0016] Furthermore, the liquid metal is a gallium-based liquid metal alloy, which, in addition to gallium, also contains indium and tin.

[0017] Furthermore, the temperature setting range in step one is 100–150°C, and the pressure holding time range is 10–20 seconds.

[0018] Furthermore, in steps two, three, and four, the distance between the printhead and the glass substrate is 1–5 mm, the spraying speed is set to 1–10 m / s and the spraying frequency is set to 1–10 kHz when filling with nano-silver ink, the spraying speed and spraying frequency are lower when filling with liquid metal than when filling with nano-silver ink, and the ambient temperature is 100–150 °C.

[0019] Furthermore, in step two, the near-infrared light source is located 5 to 20 cm directly above the glass substrate, the power of the light source is set in the range of 10 to 100 W, and the illumination time is set in the range of 1 to 10 min.

[0020] Furthermore, the heating temperature and heating time in step five are set to 150–200℃ and 5–10 min, respectively.

[0021] A glass through-hole filling and sealing device based on liquid metal with large aspect ratio includes a body, on which are provided a liquid metal multi-nozzle module and a nano-silver ink multi-nozzle module for coarse adjustment in the XYZ direction, a near-infrared light source for coarse adjustment in the X direction and telescopic adjustment in the Y direction, and a stage for fine adjustment in the XYZ direction.

[0022] Furthermore, the machine body is equipped with an XYZ fine-tuning motion displacement stage, a heated platform on the XYZ fine-tuning motion displacement stage, an X-axis coarse-tuning motion displacement stage on the machine body, a Y-axis coarse-tuning motion displacement stage and a telescopic pneumatic device on the X-axis coarse-tuning motion displacement stage, a Z-axis coarse-tuning motion displacement stage on the Y-axis coarse-tuning motion displacement stage, a liquid metal multi-nozzle module and a nano-silver ink multi-nozzle module on the Z-axis coarse-tuning motion displacement stage, and a near-infrared light source on the pneumatic device.

[0023] Furthermore, the Y-axis coarse adjustment motion displacement stage is equipped with a liquid metal storage chamber and a nano-silver ink storage device. The liquid metal storage chamber is connected to the liquid metal multi-head module through a liquid metal conduit, and the nano-silver ink storage device is connected to the nano-silver ink multi-head module through a nano-silver ink conduit. Both the liquid metal multi-head module and the nano-silver ink multi-head module are equipped with a CCD camera and a printing printhead.

[0024] The beneficial effects of this application are:

[0025] (1) Excellent filling quality. Liquid metal is used as the filling material for the large aspect ratio TGV. It has good fluidity, and precise positioning using 3D printing methods can ensure that the liquid metal flows smoothly into and fills the large aspect ratio TGV. The liquid metal has low surface tension. At the same time, plasma bombardment of the inner wall of the TGV or laser processing of micro-nano structures on the inner wall of the TGV can improve the wettability of the glass hole wall. Even for TGVs with complex shapes, the filling liquid metal is still uniformly distributed, which can avoid the generation of defects such as voids, thereby ensuring the uniformity and integrity of the filling.

[0026] (2) The interconnect structure has excellent high-frequency and high-speed electrical characteristics. Compared with traditional copper materials, liquid metal has superior conductivity, which can ensure that the filled TGV can meet the requirements of high-frequency and high-speed signal transmission. At the same time, it can form a tight electrical contact with the sealing layer material, which can reduce the risk of electrical signal fluctuations or interruptions caused by poor contact, and improve the electrical stability and reliability of the interconnect structure.

[0027] (3) Excellent heat dissipation characteristics. Liquid metal has a high thermal conductivity, which can quickly conduct heat from the chip to the heat dissipation components and the surrounding environment, reduce the chip's operating temperature, and thus improve the chip's service reliability and service life.

[0028] (4) Effective sealing structure and sealing process. Liquid metal has good fluidity. Nano-silver ink is filled into the high aspect ratio TGV using 3D printing method before and after liquid metal filling. Combined with photocuring method, a sealing layer is formed at both ends of TGV, which can effectively prevent liquid metal from overflowing, thereby ensuring that the interconnect structure has stable electrical performance.

[0029] (5) Reliable integrated liquid metal filling and sealing device. An integrated device that can simultaneously achieve liquid metal filling and nano-silver ink curing and sealing is designed. By coordinating the control of the X / Y / Z coarse and fine adjustment motion displacement stage, the nano-silver ink multi-nozzle module, the liquid metal multi-nozzle module and the near-infrared light source, high-quality and high-efficiency filling and sealing of the large aspect ratio TGV array structure can be achieved.

[0030] The aforementioned main solution and its various further alternatives can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application; furthermore, the (non-conflicting alternatives) can also be freely combined with each other and with other alternatives. Those skilled in the art, after understanding the solution of this application, will realize from the prior art and common general knowledge that there are many combinations, all of which are technical solutions to be protected by this application, and will not be exhaustively listed here. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the method described in this application.

[0032] Figure 2 This is a schematic diagram of the structure of sealing a glass substrate using heat-release adhesive tape, as described in this application.

[0033] Figure 3 This is a schematic diagram of the structure of sealing the bottom of the glass through-hole using nano-silver ink, as described in this application.

[0034] Figure 4 This is a schematic diagram of the structure used in this application to seal glass through-holes using liquid metal and nano-silver ink.

[0035] Figure 5 This is a schematic diagram of the device in this application.

[0036] In the figure: 1-glass substrate, 2-through glass via (TGV), 3-thermal release tape sealing layer, 4-PDMS substrate, 5-nano silver sealing layer, 6-liquid metal, 7-X-axis coarse adjustment motion stage, 8-Y-axis coarse adjustment motion stage, 9-Z-axis coarse adjustment motion stage, 10-XYZ fine adjustment motion stage, 11-liquid metal reservoir, 12-liquid metal conduit, 13-nano silver ink storage device, 14-nano silver ink conduit, 15-CCD camera, 16-liquid metal multi-nozzle module, 17-printing nozzle, 18-stage, 19-substrate and substrate assembly, 20-pneumatic device, 21-near-infrared light source, 22-nano silver ink multi-nozzle module. Detailed Implementation

[0037] The following non-limiting embodiments are used to illustrate this application.

[0038] Example 1

[0039] refer to Figures 1-4 As shown, a method for filling and sealing large aspect ratio glass vias based on liquid metal mainly includes filling the large aspect ratio glass vias (TGVs) with liquid metal based on inkjet 3D printing and sealing with nano-silver ink after curing. Specifically, sealing the large aspect ratio TGVs filled with liquid metal using photocured nano-silver ink effectively prevents liquid metal overflow, thereby ensuring stable electrical performance of the interconnect structure.

[0040] The specific steps for filling and sealing large aspect ratio glass vias based on liquid metal are as follows: Step 1, prepare a clean PDMS substrate 4 and a glass substrate 1 with glass vias 2, tightly adhere heat release tape between the glass substrate 1 and the PDMS substrate 4, and then place it in a heat sealer. Under the pressure and temperature of the heat sealer, the heat release tape completely melts to form a heat release tape sealing layer 3, so as to completely bond the glass substrate 1 and the PDMS substrate 4 together to form a substrate-substrate bond 19.

[0041] Step 2: The nano-silver ink multi-head module 22 is moved above the glass through hole 2 by the X-axis coarse adjustment motion displacement stage 7, Y-axis coarse adjustment motion displacement stage 8 and Z-axis coarse adjustment motion displacement stage 9 for filling. The glass through hole 2 is precisely aligned with the multi-head module by the XYZ fine adjustment motion displacement stage 10, and the nano-silver ink is filled into the bottom of the glass through hole 2. After filling, the nano-silver ink multi-head module 22 is moved away from the glass through hole 2.

[0042] The near-infrared light source 21 is moved to the top of the glass through hole 2 by the X-axis coarse adjustment motion displacement stage 7 and the pneumatic device 20 for photocuring. Then the near-infrared light source 21 is turned on to photocur the nano-silver ink to form a nano-silver sealing layer at the bottom of the glass through hole 2. After curing, the near-infrared light source 21 is moved away from the glass through hole 2.

[0043] Step three: Similarly, the X-axis coarse adjustment motion displacement stage 7, Y-axis coarse adjustment motion displacement stage 8, and Z-axis coarse adjustment motion displacement stage 9 are used to control the liquid metal multi-nozzle module 16 to move above or away from the glass through-hole 2 for filling. The XYZ fine adjustment motion displacement stage 10 is used to control the glass through-hole 2 to be precisely aligned with the multi-nozzle module. Liquid metal 6 is then filled into the hole of the glass through-hole 2, so that the liquid metal 6 is filled to a position close to the top of the glass substrate 1.

[0044] Step four: Similarly, the X-axis coarse adjustment motion displacement stage 7, Y-axis coarse adjustment motion displacement stage 8, and Z-axis coarse adjustment motion displacement stage 9 are used to control the movement of the nano-silver ink multi-head module 22 to fill or move away from the glass through-hole 2. The XYZ fine adjustment motion displacement stage 10 is used to control the glass through-hole 2 to be precisely aligned with the multi-head module. The nano-silver ink is then filled into the opening of the glass through-hole 2 and completely filled.

[0045] Then, the near-infrared light source 21 is turned on to photocur the nano-silver ink, forming a nano-silver sealing layer 5 at the opening of the glass through-hole 2. Similarly, the near-infrared light source 21 is moved to the glass through-hole 2 for photocuring or away from the glass through-hole 2 by the X-axis coarse adjustment motion displacement stage 7 and the pneumatic device 20.

[0046] Step 5: Separate the glass substrate 1 and the PDMS substrate 4 by heating. Remove the glass substrate and PDMS substrate filled with liquid metal from the device and place them on the heating stage. Separate the glass substrate and PDMS substrate using tools such as tweezers.

[0047] The glass via 2 is a large aspect ratio array, which is prepared by femtosecond laser-induced wet etching. Micro-nano structures are prepared on the inner wall of the TGV by femtosecond laser, or plasma is used to bombard the inner wall of the TGV to improve the wettability of the via wall.

[0048] The liquid metal multi-nozzle module 16 and the nano silver ink multi-nozzle module 22 are filled using inkjet 3D printing technology. The distance between the printhead array 17 of the liquid metal multi-nozzle module 16 and the nano silver ink multi-nozzle module 22 can be dynamically adjusted to adapt to TGV arrays with different spacing. The inner diameter of the printhead ranges from 5 to 80 μm.

[0049] Liquid metal is a gallium-based liquid metal alloy. In addition to gallium, it also contains indium and tin. The types and proportions of elements can be adjusted according to different needs.

[0050] The temperature setting range in step one is 100-150℃, and the pressure holding time range is 10-20s.

[0051] In steps two, three, and four, the distance between the print head 17 and the glass substrate 1 is 1–5 mm. When filling with nano-silver ink, the spray speed is set to 1–10 m / s and the spray frequency is set to 1–10 kHz. When filling with liquid metal, the spray speed and spray frequency are lower than those when filling with nano-silver ink. The ambient temperature is 100–150 °C.

[0052] In step two, the near-infrared light source 21 is located 5 to 20 cm directly above the glass substrate 1, with the light source power set in the range of 10 to 100 W and the illumination time set in the range of 1 to 10 min.

[0053] In step five, the heating temperature and heating time are set to 150–200℃ and 5–10 min, respectively.

[0054] Example 2

[0055] refer to Figure 5 As shown, a glass through-hole filling and sealing device based on liquid metal with large aspect ratio includes a body, on which are provided a liquid metal multi-nozzle module 16 and a nano silver ink multi-nozzle module 22 for coarse adjustment in the XYZ direction, a near-infrared light source 21 for coarse adjustment in the X direction and telescopic adjustment in the Y direction, and a stage 18 for fine adjustment in the XYZ direction.

[0056] The machine body is equipped with an XYZ fine-tuning motion displacement stage 10, and a heating stage 18 is provided on the XYZ fine-tuning motion displacement stage 10. The XYZ fine-tuning motion displacement stage 10 controls the precise adjustment of the stage 18, and the stage 18 drives the substrate and substrate assembly 19 to move synchronously, so as to achieve precise alignment of the hole and the nozzle, and provide a heated working environment for them.

[0057] The machine body is equipped with an X-axis coarse adjustment motion displacement stage 7, a Y-axis coarse adjustment motion displacement stage 8 and a telescopic pneumatic device 20 on the X-axis coarse adjustment motion displacement stage 7, a Z-axis coarse adjustment motion displacement stage 9 on the Y-axis coarse adjustment motion displacement stage 8, and a liquid metal multi-nozzle module 16 and a nano-silver ink multi-nozzle module 22 respectively on the Z-axis coarse adjustment motion displacement stage 9. The pneumatic device 20 is equipped with a near-infrared light source 21. The coarse adjustment motion displacement stage is used to achieve coarse adjustment of the liquid metal multi-nozzle module 16 and the nano-silver ink multi-nozzle module 22, and the coarse adjustment motion displacement stage and the pneumatic device 20 are used to achieve coarse adjustment of the near-infrared light source 21.

[0058] The Y-axis coarse adjustment motion displacement stage 8 is equipped with a liquid metal storage chamber 11 and a nano silver ink storage device 13. The liquid metal storage chamber 11 is connected to the liquid metal multi-head module 16 through a liquid metal conduit 12, and the nano silver ink storage device 13 is connected to the nano silver ink multi-head module 22 through a nano silver ink conduit 14.

[0059] Both the liquid metal multi-nozzle module 16 and the nano silver ink multi-nozzle module 22 are equipped with a CCD camera 15 and a printing nozzle 17. The CCD camera 15 provides visual comparison to assist in the motion adjustment of the position displacement stage, while the printing nozzle 17 performs the specific filling.

[0060] Implementation Cases

[0061] refer to Figures 1-5 As shown, first, prepare a clean and flat glass substrate 1 and PDMS substrate 4 with a large aspect ratio TGV array, and cut heat-release adhesive tape with appropriate width / length to the glass substrate and PDMS substrate. Apply the cut heat-release adhesive tape tightly to the surfaces of glass substrate 1 and PDMS substrate 4, ensuring that no bubbles or wrinkles form at the bonding interface. Then, align the glass substrate 1 and PDMS substrate 4 with the heat-sealing tape and place them in a heat sealer. Set the temperature to 100–150°C, apply appropriate pressure between them and hold for 10–20 seconds until the heat-release tape completely melts and adheres completely to both surfaces, forming a heat-release adhesive tape sealing layer 3.

[0062] The substrate and substrate assembly 19 (a bottom-sealed glass substrate) is placed on the stage 18 of the device, which has a heating function. By controlling the X-axis coarse adjustment motion stage 7, the Y-axis coarse adjustment motion stage 8, and the Z-axis coarse adjustment motion stage 9, the nano-silver ink multi-nozzle module 22 with a CCD camera 15 and a print head 17 array is moved directly above the glass substrate 1, so that the distance between the print head 17 array and the glass substrate is 1-5 mm. The XYZ fine adjustment motion stage 10 is then controlled to align the nozzle tip with the TGV through hole on the glass substrate.

[0063] Nano-silver ink is injected into the ink storage device and then transported to the tip of the printhead array 17 via a conduit. By setting the jetting speed to 1–10 m / s, the jetting frequency to 1–10 kHz, and the stage temperature to 100–150 °C, the nano-silver ink is filled into the high aspect ratio TGV through-holes, with a filling thickness of approximately 5–10 μm.

[0064] By controlling the X-axis coarse adjustment motion stage 7, the Y-axis coarse adjustment motion stage 8, and the Z-axis coarse adjustment motion stage 9, the nano-silver ink multi-head module 22 is moved away from directly above the glass substrate. Then, the X-axis coarse adjustment motion stage 7 and the pneumatic device 20 are controlled to move the near-infrared light source 21 to 5–20 cm directly above the glass substrate 1, and the light source power is set to 10–100 W and the illumination time to 1–10 min for photocuring. After curing, the near-infrared light source is moved away from directly above the glass substrate.

[0065] Subsequently, by controlling three coarse adjustment displacement stages, the liquid metal multi-nozzle module 16 is moved to a position 1-5 mm directly above the glass substrate 1, injecting liquid metal into the reservoir. The liquid metal is then transported to the tip of the printhead array via conduits. By setting appropriate injection speed and frequency, the liquid metal is injected into the high aspect ratio TGV, filling it to a depth of 5-10 μm above the TGV. The liquid metal multi-nozzle module 16 is then moved away from directly above the glass substrate 1.

[0066] The nano-silver ink is filled again using the same method, and the near-infrared light source 21 is moved to a position 5-20 cm directly above the glass substrate. The light source power is set to 10-100 W and the illumination time to 1-10 min for photocuring. After curing, the filled liquid metal can be sealed.

[0067] The glass substrate and PDMS substrate filled with liquid metal are moved out of the device and placed on a heating stage. The heating temperature and heating time are set to 150-200℃ and 5-10min, respectively. The sealing layer formed by the heat release tape will gradually soften, and the glass substrate and PDMS substrate can be separated using tools such as tweezers.

[0068] The foregoing basic examples and their further alternative examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed in this application. In the scheme of this application, each alternative example can be arbitrarily combined with any other basic example and alternative example.

[0069] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for filling and sealing large aspect ratio glass through-holes based on liquid metal, characterized in that, Includes the following steps: Step 1: Prepare a PDMS substrate (4) and a glass substrate (1) with glass vias (2). Apply heat release tape tightly between the glass substrate (1) and the PDMS substrate (4). Then place the substrate in a heat sealer. The heat release tape melts to form a heat release tape sealing layer (3) to bond the glass substrate (1) and the PDMS substrate (4) together. Step 2: Fill the bottom of the glass through hole (2) with nano silver ink, and then turn on the near-infrared light source (21) to cure the nano silver ink by light, so as to form a nano silver sealing layer (5) at the bottom of the glass through hole (2); Step 3: Fill the glass through hole (2) with liquid metal (6); Step 4: Fill the opening of the glass through hole (2) with nano silver ink and then turn on the near-infrared light source (21) to cure the nano silver ink by light, so as to form a nano silver sealing layer (5) at the opening of the glass through hole (2). Step 5: Heat the glass substrate (1) and the PDMS substrate (4) to separate them.

2. The method for filling and sealing large aspect ratio glass through-holes based on liquid metal according to claim 1, characterized in that: The nano-silver ink multi-nozzle module (22) is moved above the glass through hole (2) to fill or move away from the glass through hole (2) by the X-axis coarse adjustment motion displacement stage (7), Y-axis coarse adjustment motion displacement stage (8) and Z-axis coarse adjustment motion displacement stage (9); the liquid metal multi-nozzle module (16) is moved above the glass through hole (2) to fill or move away from the glass through hole (2) by the X-axis coarse adjustment motion displacement stage (7), Y-axis coarse adjustment motion displacement stage (8) and Z-axis coarse adjustment motion displacement stage (9); the near-infrared light source (21) is moved to the glass through hole (2) for photocuring or moves away from the glass through hole (2) by the X-axis coarse adjustment motion displacement stage (7) and the pneumatic device (20); the glass through hole (2) is precisely aligned with the multi-nozzle module by the XYZ fine adjustment motion displacement stage (10).

3. The method for filling and sealing large aspect ratio glass through-holes based on liquid metal according to claim 1, characterized in that: The glass through-hole (2) is a large aspect ratio array, which is prepared by femtosecond laser-induced wet etching method, and micro-nano structures are prepared on the inner wall of TGV by femtosecond laser, or by plasma bombardment of the inner wall of TGV; the liquid metal multi-nozzle module (16) and the nano silver ink multi-nozzle module (22) are based on inkjet 3D printing technology.

4. The method for filling and sealing large aspect ratio glass through-holes based on liquid metal according to claim 1, characterized in that: The liquid metal is a gallium-based liquid metal alloy, which, in addition to gallium, also contains indium and tin.

5. The method for filling and sealing large aspect ratio glass through-holes based on liquid metal according to claim 1, characterized in that: The temperature setting range in step one is 100-150℃, and the pressure holding time range is 10-20s.

6. The method for filling and sealing large aspect ratio glass through-holes based on liquid metal according to claim 1, characterized in that: In steps two, three, and four, the distance between the print head (17) and the glass substrate (1) is 1–5 mm. When filling with nano-silver ink, the spray speed is set to 1–10 m / s and the spray frequency is set to 1–10 kHz. When filling with liquid metal, the spray speed and spray frequency are lower than those when filling with nano-silver ink. The ambient temperature is 100–150 °C. In step two, the near-infrared light source (21) is located 5–20 cm directly above the glass substrate (1). The light source power is set to 10–100 W and the illumination time is set to 1–10 min.

7. The method for filling and sealing large aspect ratio glass through-holes based on liquid metal according to claim 1, characterized in that: In step five, the heating temperature and heating time are set to 150–200℃ and 5–10 min, respectively.

8. A device for filling and sealing glass through-holes with a large aspect ratio based on liquid metal, comprising a body, characterized in that: The machine body is equipped with a liquid metal multi-nozzle module (16) for coarse adjustment in the XYZ direction and a nano silver ink multi-nozzle module (22). The machine body is also equipped with a near-infrared light source (21) for coarse adjustment in the X direction and telescopic adjustment in the Y direction, and a stage (18) for fine adjustment in the XYZ direction.

9. The device for filling and sealing large aspect ratio glass through-holes based on liquid metal according to claim 8, characterized in that: The machine body is equipped with an XYZ fine-tuning motion displacement stage (10), and a heated platform (18) is provided on the XYZ fine-tuning motion displacement stage (10). The machine body is equipped with an X-axis coarse-tuning motion displacement stage (7), and a Y-axis coarse-tuning motion displacement stage (8) and a telescopic pneumatic device (20) are provided on the X-axis coarse-tuning motion displacement stage (8). A Z-axis coarse-tuning motion displacement stage (9) is provided on the Z-axis coarse-tuning motion displacement stage (9). A liquid metal multi-nozzle module (16) and a nano-silver ink multi-nozzle module (22) are provided on the Z-axis coarse-tuning motion displacement stage (9). A near-infrared light source (21) is provided on the pneumatic device (20).

10. The device for filling and sealing large aspect ratio glass through-holes based on liquid metal according to claim 8, characterized in that: The Y-axis coarse adjustment motion displacement stage (8) is equipped with a liquid metal storage chamber (11) and a nano silver ink storage device (13). The liquid metal storage chamber (11) is connected to the liquid metal multi-head module (16) through a liquid metal conduit (12). The nano silver ink storage device (13) is connected to the nano silver ink multi-head module (22) through a nano silver ink conduit (14). Both the liquid metal multi-head module (16) and the nano silver ink multi-head module (22) are equipped with a CCD camera (15) and a printing nozzle (17).

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