Micro pipette, meniscus confinement electrodeposition device and preparation method of metal interconnection microstructure
By setting an inclined liquid outlet and a curved liquid surface confined electrodeposition device at the front end of the micropipette, a one-step direct writing preparation of metal bridge interconnection microstructures is achieved, which solves the problems of low preparation efficiency and substrate damage in traditional methods and achieves efficient and low-cost metal interconnection effects.
Patent Information
- Application Number
- CN202511159979.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-19
- Publication Date
- 2025-10-17
AI Technical Summary
Existing technologies make it difficult to achieve low-temperature, one-step direct writing to prepare metal bridge interconnect microstructures, and traditional methods are prone to thermal damage and microcracks on the substrate, making it difficult to achieve wire bonding below 10μm.
The liquid outlet at the front end of the micropipette is set as an inclined surface to form a side opening. Combined with the curved liquid surface confined electrodeposition device, the movement of the micropipette is controlled by a three-axis displacement platform to form a stable curved liquid surface, realizing the one-step direct writing preparation of metal interconnect microstructures.
The one-step forming of metal interconnect microstructures is achieved with micron-level resolution, which reduces process costs, avoids damage to the substrate caused by high temperature, and improves preparation efficiency and process simplicity.
Smart Images
Figure CN120797150A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of electrochemical additive manufacturing, and particularly relates to a micro pipette, a meniscus confined electrodeposition device and a preparation method of a metal interconnection microstructure. BACKGROUND
[0002] With the rapid development of the fields of semiconductor and micro robot, many micro products are born, and the metal interconnection microstructure is the key to ensure the effective operation of these micro products. How to efficiently and low-costly prepare the metal interconnection microstructure is the focus of researchers. At present, the traditional wire bonding process mainly uses metal wires such as gold, aluminum and copper to establish the connection between the wire and the internal chip of the semiconductor, and the main methods include thermal compression bonding, ultrasonic bonding and thermal acoustic bonding. These methods need heating or pressurizing, which can cause thermal damage and micro cracks of the substrate, resulting in chip performance failure. In addition, the traditional wire bonding process is difficult to realize wire bonding below 10 μm.
[0003] Meniscus confined electrodeposition (MCED) is a metal interconnection technology that can realize low-temperature in-situ growth. A micro-nano meniscus formed between a very thin anode tip and a cathode substrate is used as a reaction electrolytic cell. The forming precision depends on the size of the anode tip opening, and a micropipette with micron or nanometer aperture is generally used as the anode, so the forming precision is very high. The deposition range only occurs in the micro-nano meniscus area, the cost is low, the forming freedom is high, and it is very suitable for the manufacture of micro-nano metal structure.
[0004] At present, MCED has realized the technologies of planar horizontal printed metal interconnection and metal bridge interconnection. The planar horizontal printed metal interconnection can cause the body resistance of the printed metal structure to increase significantly, and the interconnection process stability is strongly related to the surface roughness of the processed workpiece. The excessive surface roughness can directly cause the interruption of the planar printing process. The metal line width is affected by the horizontal wetting force caused by the difference in wettability of different processed workpiece surfaces and the electrocapillary effect, and the line width widening phenomenon is easy to occur, which seriously restricts the process repeatability. Compared with the planar horizontal printed metal interconnection technology, the metal bridge interconnection technology can avoid the above defects, but due to the inherent limitations of the flat nozzle structure design, the inclination angle of the meniscus should not be too large, otherwise the meniscus will be pulled off, resulting in printing interruption.
[0005] Most of the current metal bridge interconnection technologies are divided into two steps, that is, deposition from two cathode contact points to the upper path in sequence, and finally completing the metal bridge butt joint in the middle region of the two cathode contact points, which makes the preparation time longer and increases the complexity of the process. Therefore, it is necessary to develop a low-temperature one-step direct writing metal bridge interconnection technology. SUMMARY
[0006] The technical problem solved by the present application is to provide a micro pipette, a meniscus confined electrodeposition device and a preparation method of metal interconnection microstructure, which realizes one-step direct writing preparation of metal interconnection microstructure in a single deposition process.
[0007] To solve the above technical problems, according to one aspect of the present application, a micro pipette is provided, wherein a liquid outlet at a front end of the micro pipette is provided as an inclined surface, a side opening is formed at the liquid outlet, and an included angle between the inclined surface and a horizontal plane ranges from 15° to 75°.
[0008] According to another aspect of the present application, a meniscus confined electrodeposition device is provided, which comprises a cathode substrate, an anode rod and a micro pipette, the cathode substrate is fixed on a surface of a three-axis displacement platform, the anode rod is connected to a platinum anode wire and the platinum anode wire is arranged in an electrolyte of the micro pipette to form a meniscus between the cathode substrate and a tip of the micro pipette.
[0009] As a preferred embodiment, the micro pipette is fixed at a bottom of a micro pipette holder, the anode rod is arranged at a top of the micro pipette holder, a lower end of the anode rod is connected to the platinum anode wire, the anode rod is connected to a positive electrode of a power supply, a negative electrode of the power supply is connected to a negative electrode of an ammeter, and the cathode substrate is connected to a positive electrode of the ammeter.
[0010] As a preferred embodiment, a channel for inputting an electrolyte is arranged in the micro pipette holder, a liquid inlet identical to the channel is arranged on a side wall of the micro pipette holder, the liquid inlet is connected to a liquid storage tank for storing the electrolyte through a conduit, and the liquid storage tank is connected to a gas pressure instrument through a conduit.
[0011] As a preferred embodiment, the surface of the three-axis displacement platform is connected to a computer, a theoretical moving speed is set by the computer, and the three-axis displacement platform is controlled to move by the computer.
[0012] As a preferred embodiment, the bottom of the three-axis displacement platform is mounted on an optical breadboard, and the optical breadboard is fixed on a horizontal support table.
[0013] According to another aspect of the present application, a preparation method of metal interconnection microstructure is provided, which adopts the meniscus confined electrodeposition device described above, and comprises the following steps. Step one: control the three-axis displacement platform so that the micro pipette opening contacts the cathode substrate; Step two: control the output gas pressure of the gas pressure instrument to make the micro pipette output the electrolyte, control the retreat speed and distance of the three-axis displacement platform to make a stable meniscus formed between the cathode substrate and the micro pipette opening, and then stop the retreat; Step three: preset the deposition morphology as ideal cylinder, the diameter of the deposited metal structure is equal to the inner diameter of the micropipette; start the power supply, when the ammeter shows a stable current signal, design the printing track according to the spatial morphology characteristics of the printed metal structure, drive the three-axis displacement platform at the theoretical moving speed, and the metal microstructure will be electrodeposited along the direction guided by the meniscus; Step four: when the micropipette moves to the end of the printing track, separate the meniscus, and complete the printing.
[0014] As a preferred embodiment, the theoretical moving speed of the three-axis displacement platform in step three is calculated according to the formula , wherein, v is the growth speed of the metal structure, i is the loop current in the electrodeposition process, M and p are the molar mass and mass density of the electrodeposited material, respectively, n is the number of transferred electrons, F is the Faraday constant, D is the diameter of the deposited metal structure.
[0015] As a preferred embodiment, the loop current i is obtained by recording and saving the time-current curve data in real time through the ammeter.
[0016] As a preferred embodiment, in step four, the printing track includes: firstly control the three-axis displacement platform to move vertically backward at a speed v , then under the guidance of the meniscus, the metal structure is electrodeposited along the shape and direction of the meniscus; secondly control the three-axis displacement platform to move obliquely downward at a speed v , until the distance between the top of the deposited metal column and the lower layer of the cross layer is equal to the thickness of the cross layer L ; then control the three-axis displacement platform to move horizontally backward at a speed v , until the opening tip of the micropipette reaches the high layer position of the cathode substrate, and the preparation of the cross-layer interconnection structure is completed.
[0017] The micropipette provided by the application has a micropipette tip with a flat mouth and a side opening, which expands the controllable inclination angle of the meniscus, thereby realizing one-step direct writing preparation of the metal interconnection microstructure in a single deposition process and improving the preparation efficiency.
[0018] The present application forms a stable meniscus between the cathode substrate and the micro pipette tip by air pressure instrument extruding electrolyte; according to the three-dimensional space characteristics of the required interconnection structure, the motion trajectory of the three-axis displacement platform is regulated, so that the micro pipette tip starts relative motion according to the motion trajectory, under the action of the electric field, the metal interconnection microstructure is electrodeposited along the direction guided by the meniscus, when the micro pipette tip reaches the predetermined position, the power is turned off and the meniscus is separated, the method realizes one-time forming of the metal interconnection microstructure, has micron-level resolution, low process cost and does not need post-processing and other technical advantages.
[0019] In addition, the present application belongs to low-temperature process technology, which saves energy while eliminating the damage of high temperature to the printing substrate; different electrolytes can be selected for the preparation of metal interconnection microstructure according to the type of metal to be deposited, and the process is simple. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 is a structural schematic diagram of the micro pipette; Figure 2 is a structural schematic diagram of the meniscus limited electrodeposition device; Figure 3 is a connection schematic diagram between the liquid storage tank, air pressure instrument and micro pipette holder; Figure 4 is a structural schematic diagram of the micro pipette holder and micro pipette; Figure 5 is a schematic diagram of meniscus formation in the process of preparing metal microstructure; Figure 6 is a printing trajectory schematic diagram of preparing cross-layer interconnection microstructure; Figure 7 is a physical map of the prepared copper interconnection microstructure.
[0021] In the figure, 1 is a liquid storage tank, 2 is a micro pipette holder, 3 is an air pressure instrument, 4 is a micro pipette, 5 is a power supply, 6 is an ammeter, 7 is a cathode substrate, 8 is a support, 9 is a microscope, 10 is a computer, 11 is a three-axis displacement platform, 12 is an optical breadboard, and 13 is a horizontal support table. 101 is an electrolyte, 102 is a long catheter, and 103 is a short catheter. 201 is a platinum anode wire, 202 is an anode rod, 203 is a quartz sealing lock head, 204 is a rubber sealing ring, and 205 is a quartz sealing nut. DETAILED DESCRIPTION
[0022] In the existing meniscus limited electrodeposition (MCED) process, one-step direct writing metal interconnection microstructure preparation cannot be realized due to the limitation of the inclination angle of the meniscus, based on this, the micro pipette 4 provided by a typical embodiment of the present application, like Figure 1As shown, the liquid outlet at the front end of the micro pipette 4 is provided with an inclined surface, and a side opening is formed at the liquid outlet. The side opening of the micro pipette 4 enlarges the controllable inclination angle of the meniscus, so that the one-step direct writing preparation of the metal interconnection microstructure can be realized in a single deposition process.
[0023] In this embodiment, the included angle between the inclined surface and the horizontal plane ranges from 15° to 75°, for example, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, or 75°. Different opening sizes of the micro pipette can be selected for processing according to the spatial features of the workpiece to be processed. The larger the cross-sectional area of the side opening, the thicker the prepared micro metal structure, and the smaller the cross-sectional area of the side opening, the thinner the prepared micro metal structure. According to the spatial features of the printed metal interconnection microstructure, the shape of the side opening of the micro pipette 4 can be a single-sided opening or a double-sided opening, etc., wherein the double-sided opening can be used to prepare a "broken line" shape with a low angle (for example, an inclination angle of 5°), and the double-sided opening can be realized by using FIB technology or precise polishing.
[0024] On the basis of the above embodiment, another typical embodiment of the present application provides a meniscus confined electrodeposition device. As shown in Figure 2 The meniscus confined electrodeposition device comprises a cathode substrate 7, an anode rod 202, and a micro pipette 4.
[0025] The cathode substrate 7 is fixed on the surface of a three-axis displacement platform 11, and the anode rod 202 is connected to a platinum anode wire 201 and places the platinum anode wire 201 in the electrolyte 101 of the micro pipette 4 to form a meniscus between the cathode substrate 7 and the tip of the micro pipette 4.
[0026] As shown in Figure 3 , Figure 4 The micro pipette 4 is fixed at the bottom of a micro pipette holder 2, the anode rod 202 is arranged at the top of the micro pipette holder 2, and the lower end of the anode rod 202 is connected to the platinum anode wire 201. The anode rod 202 is connected to the positive electrode of a power supply 5, the negative electrode of the power supply 5 is connected to the negative electrode of an ammeter 6, and the cathode substrate 7 is connected to the positive electrode of the ammeter 6.
[0027] A channel for inputting electrolyte is formed in the micro pipette holder 2, and a liquid inlet identical to the channel is arranged on the sidewall of the micro pipette holder 2. The liquid inlet is connected to a liquid storage tank 1 for storing electrolyte 101 through a long conduit 102, and the liquid storage tank 1 is connected to a gas pressure instrument 3 through a short conduit 103.
[0028] In the present application, the surface of the three-axis displacement platform 11 is connected to the computer 10, and the computer 10 sets the theoretical moving speed and controls the movement of the three-axis displacement platform 11. The bottom of the three-axis displacement platform 11 is mounted on the optical face breadboard 12, and the optical face breadboard 12 is fixed on the horizontal support table 13.
[0029] When assembling the meniscus confined electrodeposition device, first, the electrolyte 101 corresponding to the required printed metal is configured, and is added to the liquid storage tank 1. The long catheter 102 is inserted, and the end of the long catheter 102 is completely immersed in the electrolyte 101. Then, the short catheter 103 is inserted, and the end of the short catheter 103 is located in the upper part of the liquid level of the electrolyte 101. The other end of the long catheter 102 is connected to the micro pipette holder 2, and the other end of the short catheter 103 is connected to the air pressure instrument 3.
[0030] According to the size of the required printed metal, the micro pipette 4 with a suitable opening size and the platinum anode wire 201 with a suitable thickness are selected. The platinum anode wire 201 is connected to the lower part of the anode rod 202, and then is fixed by the quartz sealing lock head 203. The platinum anode wire 201 is inserted into the micro pipette 4, the micro pipette 4 is vertically inserted from the lower part of the micro pipette holder 2, is sleeved into the rubber sealing ring 204, and finally is fixed by the quartz sealing nut 205.
[0031] The anode rod 202 is connected to the positive electrode of the power supply 5 through a wire, and the negative electrode of the ammeter 6 is connected to the negative electrode and the cathode base 7 of the power supply 5 through wires. The power supply 5 adopts a constant current mode output.
[0032] Finally, the assembled micro pipette holder 2 is fixed on the support 8. The side opening direction of the micro pipette 4 is adjusted by using the microscope 9 to observe in real time, so that the side opening direction is opposite to the horizontal movement direction of the prepared metal interconnection microstructure.
[0033] Another typical embodiment of the present application provides a preparation method of a metal interconnection microstructure, which is implemented by using the meniscus confined electrodeposition device provided in the above embodiment, and includes the following steps one to four.
[0034] Step one: control the three-axis displacement platform 11, so that the micro pipette 4 opening contacts the cathode base 7.
[0035] Step two: control the output air pressure of the air pressure instrument 3 to make the micro pipette 4 output electrolyte, control the retreat speed and distance of the three-axis displacement platform 11, so that a stable meniscus is formed between the cathode base 7 and the micro pipette 4 opening (as shown in the figure), and then stop the retreat. Figure 5
[0036] Step 3: Preset the deposition morphology as an ideal cylinder, and the diameter of the deposited metal structure is equal to the inner diameter of the micropipette; start the power supply 5. When the ammeter 6 shows a stable current signal, design the printing trajectory according to the spatial morphological characteristics of the printed metal structure. Control the computer 10 to drive the three-axis displacement platform 11 according to the theoretical moving speed, and the metal microstructure will be electrodeposited along the direction guided by the curved liquid surface.
[0037] According to the formula Calculate the theoretical moving speed of the three-axis displacement platform, where: v is the growth rate of the metal structure, i is the loop current during electrodeposition, M and p are the molar mass and mass density of the electrodeposited material, n is the number of transferred electrons, F is the Faraday constant, D is the diameter of the deposited metal structure. i It is obtained by recording and saving the time-current curve data in real time through the ammeter.
[0038] Step 4: When the micropipette 4 moves relatively to the end point of the printing track, the power is turned off, the curved liquid surface is separated, and the printing is completed.
[0039] like Figure 6 As shown, in this step, the printing track includes: like Figure 6 As shown in a, first control the three-axis displacement platform at a speed v Vertical retreat ,Under the guidance of the meniscus, the metal structure is electrodeposited following the shape and direction of the meniscus; like Figure 6 As shown in b, the three-axis displacement platform is controlled to move at a speed along the direction of the opening on the side of the micropipette. v Retreat obliquely downward until the distance from the top of the deposited metal column to the lower layer of the cross-layer is equal to the thickness of the cross-layer L ; like Figure 6 As shown in c, the three-axis displacement platform is controlled to move at a speed along the direction of the opening on the side of the micropipette. v Move back horizontally until the open tip of the micropipette reaches the upper level of the cathode base ( Figure 6 As shown in (d), the preparation of the cross-layer interconnection structure is completed.
[0040] A relatively specific embodiment is provided below to further clearly and completely illustrate the technical solution claimed in the present invention.
[0041] In this embodiment, the copper cathode substrate 7 with a cross-layer thickness L of 20 μm is used as the cathode substrate 7.
[0042] A 0.6 M copper sulfate solution with a pH of 1 is prepared as the electrolyte 101, and the copper sulfate solution is added to the reservoir tank 1. A long conduit 102 is inserted into the reservoir tank 1, with the end of the long conduit 102 completely immersed in the electrolyte 101. A short conduit 103 is further inserted, with the end of the short conduit 103 located above the liquid level of the electrolyte 101. The other end of the long conduit 102 is connected to the micro pipette holder 2, and the other end of the short conduit 103 is connected to the air pressure instrument 3.
[0043] A micro pipette 4 with a flat mouth and a 45° side opening and an inner diameter of about 5 μm is selected, and a platinum anode wire 201 with a diameter of 30 μm is used. The platinum anode wire 201 is connected to the lower part of the anode rod 202. The platinum anode wire 201 is inserted into the micro pipette 4, and then the micro pipette 4 is vertically inserted from the lower part of the micro pipette holder 2. The micro pipette 4 is then sleeved into the rubber sealing ring 204, and finally fixed by the quartz sealing nut 205.
[0044] The anode rod 202 is connected to the positive electrode of the power supply 5 through a wire, and the negative electrode of the ammeter 6 is connected to the negative electrode of the power supply 5 and the cathode substrate 7 through wires. The assembled micro pipette holder 2 is fixed on the support 8.
[0045] The side opening direction of the micro pipette 4 is adjusted by real-time observation using the microscope 9, so that the side opening direction is opposite to the horizontal movement direction for preparing the metal interconnection microstructure. The computer 10 is used to control the three-axis displacement platform 11, so that the opening of the micro pipette 4 just contacts the cathode substrate 7.
[0046] The output air pressure of the air pressure instrument 3 is controlled, and then the three-axis displacement platform 11 is slowly controlled to retreat 2 μm at a speed of 1 μm / s, so that a stable meniscus is formed between the cathode substrate 7 and the opening of the micro pipette 4, and then the retreat is stopped.
[0047] The preset deposition morphology is an ideal cylinder, and the diameter of the deposited metal structure is equal to the inner diameter of the micro pipette 4, which is 5 μm. The theoretical moving speed of the three-axis displacement platform 11 is calculated by the formula wherein, v is the growth speed of the metal structure, i is the loop current during electrodeposition, M and p are the molar mass and mass density of the electrodeposited material, respectively, n is the number of transferred electrons, F is the Faraday constant, and D is the diameter of the deposited metal structure.
[0048] Taking printing copper as an example, wherein,i =100nA, M =63.55g / mol, n =2, F =96485 c / mol, p =8.96g / cm 3 , D =5μm. Calculation can get v= 0.187μm / s.
[0049] Start power 5, when ammeter 6 shows stable current signal, use computer 10 to design printing track, printing track includes: (1) first control three-axis displacement platform 11 to speed v Vertical retreat (10μm), under the guidance of meniscus, metal structure will be along with meniscus shape and direction electrodeposition; (2) then along the direction of micro pipette 4 side opening, control three-axis displacement platform 11 to speed v Oblique 45° downward retreat, until the distance between the top of the deposited metal column and the low layer of the cross layer is exactly equal to the thickness of the cross layer L (20μm); (3) then along the direction of micro pipette 4 side opening, control three-axis displacement platform 11 to speed v Horizontal backward movement, until the opening tip of micro pipette 4 reaches the high layer position of cathode substrate 7, complete the preparation of cross layer interconnection structure.
[0050] Close power 5, separate meniscus, complete printing.
[0051] In the present application, the indicative orientation words such as "lower", "oblique 45° downward", "retreat", "horizontal backward", "end" are based on the orientation shown in the drawings, which are for the convenience of description, and not for indicating that the device has this specific orientation, so it cannot be understood as a limitation of the present application.
[0052] The scope of protection required by the present application is not limited to the above specific embodiments, obviously, for those skilled in the art, the present application can have many modifications and changes, such as the present application can also realize one-step direct writing of planar interconnection, one-step direct writing of cross layer interconnection, etc. The prepared interconnection structure also has many types, which can be spiral structure interconnection, cantilever structure interconnection, etc. Any modification, improvement and equivalent replacement within the concept and principle of the present application should be included in the protection scope of the present application.
Claims
1. A micropipette, characterized in that: The liquid outlet at the front end of the micropipette is set as an inclined surface, forming a side opening at the liquid outlet, and the angle between the inclined surface and the horizontal plane ranges from 15° to 75°.
2. A meniscus confined electrodeposition device, characterized in that: The invention comprises a cathode base, an anode rod and the micropipette according to claim 1, wherein the cathode base is fixed on the surface of a three-axis displacement platform, the anode rod is connected to a platinum anode wire and the platinum anode wire is placed in the electrolyte of the micropipette, and a curved liquid surface is formed between the cathode base and the tip of the micropipette.
3. The meniscus confined electrodeposition device according to claim 2, characterized in that: The micropipette is fixed at the bottom of the micropipette holder, the anode rod is set at the top of the micropipette holder, the lower end of the anode rod is connected to the platinum anode wire, the anode rod is connected to the positive pole of the power supply, the negative pole of the power supply is connected to the negative pole of the ammeter, and the cathode base is connected to the positive pole of the ammeter.
4. The meniscus confined electrodeposition device according to claim 3, characterized in that: The micropipette holder has a channel for inputting electrolytes, and a liquid inlet identical to the channel is provided on the side wall of the micropipette holder. The liquid inlet is connected to a liquid storage tank for storing electrolytes through a conduit, and the liquid storage tank is connected to an air pressure gauge through a conduit.
5. The meniscus confined electrodeposition device according to claim 4, characterized in that: The surface of the three-axis displacement platform is connected to a computer, and the computer sets a theoretical moving speed and controls the movement of the three-axis displacement platform.
6. The meniscus confined electrodeposition device according to claim 5, characterized in that: The bottom of the three-axis displacement platform is installed on an optical breadboard, and the optical breadboard is fixed on a horizontal support platform.
7. A method for preparing a metal interconnect microstructure, characterized in that: The meniscus confined electrodeposition device according to claim 5 comprises: Step 1: Control the three-axis displacement platform so that the opening of the micropipette contacts the cathode substrate; Step 2: Control the output pressure of the barometer to make the micropipette discharge electrolyte, control the retraction speed and distance of the three-axis displacement platform to form a stable meniscus between the cathode substrate and the micropipette opening, and then stop retraction; Step 3: The deposited morphology is preset to an ideal cylinder, with the diameter of the deposited metal structure equal to the inner diameter of the micropipette. The power is turned on. When the ammeter displays a stable current signal, the printing trajectory is designed based on the spatial morphology of the printed metal structure. The three-axis displacement stage is driven at the theoretical movement speed, and the metal microstructure is electrodeposited along the direction guided by the meniscus. Step 4: When the micropipette moves relatively to the end point of the printing track, the curved liquid surface is separated to complete the printing.
8. The method for preparing a metal interconnect microstructure according to claim 7, wherein: In step 3, according to the formula Calculate the theoretical moving speed of the three-axis displacement platform, where: v is the growth rate of the metal structure, i is the loop current during electrodeposition, M and ρ are the molar mass and mass density of the electrodeposited material, n is the number of transferred electrons, F is the Faraday constant, D is the diameter of the deposited metal structure.
9. The method for preparing a metal interconnect microstructure according to claim 8, wherein: The loop current i It is obtained by recording and saving the time-current curve data in real time through the ammeter.
10. The method for preparing a metal interconnect microstructure according to claim 7, 8 or 9, wherein: In step 4, the printing trajectory includes: First control the three-axis displacement platform at speed v Vertical retreat ,Under the guidance of the meniscus, the metal structure is electrodeposited following the shape and direction of the meniscus; Then, along the direction of the opening on the side of the micropipette, control the three-axis displacement platform at a speed of v Retreat obliquely downward until the distance from the top of the deposited metal column to the lower layer of the cross-layer is equal to the thickness of the cross-layer L ; Then, the three-axis displacement platform is controlled to move at a speed along the direction of the opening on the side of the micropipette. v Move backward horizontally until the open tip of the micropipette reaches the upper layer of the cathode substrate, completing the preparation of the cross-layer interconnection structure.