CN115003045B - A method for micro-nano 3D printing of ceramic-based circuits based on electric field-driven spray deposition - Google Patents

Abstract

The invention discloses a method for manufacturing high-precision ceramic-based circuits based on electric field-driven spray deposition micro-nano 3D printing. First, a layer of sacrificial layer material is coated on the pretreated ceramic substrate, and the sacrificial layer is solidified; subsequently, According to the design circuit, conductive ink is used as the printing material, and electric field-driven spray deposition micro-nano 3D printing is used to print a conductive structure on the ceramic substrate coated with the sacrificial layer; then, a high-temperature sintering process is used to remove the sacrificial layer and the conductive ink. Various organic solvents are used to combine the conductive circuit and the ceramic substrate into one through conductive ink; finally, the sintered ceramic circuit board is post-processed and the finished product is dried. The invention utilizes three strategies: coating of sacrificial layer, electric field-driven spray deposition micro-nano 3D printing, and high-temperature sintering of printed circuits to organically combine to achieve efficient and low-cost manufacturing of high-precision ceramic-based circuits.

Description

A method of micro-nano 3D printing ceramic-based circuits based on electric field-driven spray deposition

Technical field

The invention belongs to the field of ceramic-based circuit manufacturing and micro-nano-scale 3D printing, and particularly relates to a high-precision ceramic-based circuit manufacturing method based on electric field-driven spray deposition micro-nano 3D printing, which can realize large-size and high-precision ceramic-based circuit boards with high efficiency and low cost. cost of manufacturing.

Background technique

Compared with traditional organic circuit boards and metal-based circuit boards, ceramic-based circuit boards (ceramic-based circuits) have many outstanding features and unique advantages, including: (1) Excellent thermal conductivity, good temperature cycling and high temperature resistance impact; (2) high insulation resistance and dielectric strength, high reliability; (3)) low dielectric coefficient, excellent high-frequency characteristics and low dielectric loss, which effectively reduces the signal delay time and improves the transmission efficiency; (4) Low thermal expansion coefficient, especially its thermal expansion coefficient is well matched with semiconductor silicon wafers and chips; (5) High air tightness, extreme harsh environments such as high humidity, high temperature, strong radiation and corrosion have little impact on electronic devices; (6) High stiffness and strength, effective in supporting and protecting circuits and chips; (7) Easy to achieve high-density wiring, high insulation resistance, strong bonding between circuit patterns and ceramic substrates; (8) Good mechanical properties, low warping Curvature, high hardness, and high dimensional accuracy; (9) It has both excellent bonding strength and electrical properties; (10) It has a very low secondary electron emission coefficient; (11) It is non-toxic and has good chemical stability; (12) High stability and high thermomechanical properties. Therefore, ceramic-based circuit boards have many excellent properties such as high thermal conductivity, high heat resistance, low thermal expansion coefficient, and high dimensional stability, and have been used in power electronics, high-power LED packaging substrates, multi-chip modules (MCM), and IGBT modules. , high-frequency antennas, microwave wireless communications, high-temperature semiconductor packaging and many other fields have been widely used, especially in aerospace, national defense and military, deep sea, deep space, high frequency and high-speed communications and other fields.

With the widespread popularity of strategic emerging industries and industrial applications such as 5G communications, artificial intelligence, cloud technology, driverless driving, and the Internet of Things in recent years, high-frequency, high-speed, and high-density integration have become important development trends and trends in today's electronic products. direction, which places increasingly higher requirements on the dielectric constant, dielectric loss, heat resistance, corrosion resistance and other properties of circuit substrates. Therefore, the demand for ceramic-based circuit boards is currently increasing, and the requirements for their performance are also getting higher and higher. This poses many new challenges for the manufacturing of high-performance ceramic-based circuit boards: (1) Higher precision, that is, smaller line width and line spacing of circuits to meet the requirements of high density, high integration, and miniaturization; (2) Continuously improve the interconnection density of ceramic substrates, achieve 3D integration, realize three-dimensional manufacturing and curved surface conformal manufacturing of ceramic circuits, and meet the requirements of high integration, high precision, and high conductivity; (3) Manufacturing technology has lower cost , higher efficiency, simpler manufacturing process, especially the characteristics of green and environmentally friendly production, to overcome the serious problems of traditional photolithography, etching, etc. that produce a large amount of waste liquid, waste gas, waste residue, etc., and pollute the environment during production.

At present, domestic and foreign industrialized ceramic circuit board manufacturing technologies (ceramic surface metal patterning) mainly include: screen printing, direct copper plating (DPC), direct copper plating (DBC), laser activation metallization, inkjet printing activation material + selectivity Chemical plating, etc. Screen printing technology is widely used in high-temperature co-fired ceramics (HTCC) and low-temperature co-fired ceramics (LTCC). However, the precision of using screen printing to manufacture thick film circuits is low, the line width is generally greater than 60 μm, and due to the rough ceramic surface, The thickness deviation of the manufactured circuits is large, especially for large-size substrates, and the consistency is even worse, which cannot meet the requirements of high-precision ceramic-based circuit board manufacturing. Whether it is a direct copper plating process or a direct copper coating process, they usually need to first deposit a layer of copper on the ceramic substrate, and then use photolithography, etching and other processes to achieve metal copper patterning (manufacturing of conductive circuits). Photolithography Although the etching process can realize the manufacturing of high-precision wire (electrical) circuits, the production cost is high and the process is complex (copper plating or copper coating on the ceramic substrate, photoresist coating, photolithography, etching, and photoresist removal). , post-processing, etc.), low efficiency, high requirements for production conditions, especially a large amount of waste of copper, and the generation of a large amount of waste liquid, waste gas, waste residue, etc., serious environmental pollution, future applications are increasingly subject to limitations, especially in the field of civil engineering where it is widely used. In addition, this technology can only manufacture high-precision circuits on flat ceramic substrates, and cannot achieve high-precision wiring and conformal ceramic circuit manufacturing on three-dimensional curved and non-flat ceramic substrates, which limits the use of ceramic-based circuit boards in electronic packaging. Widely used in many fields. Laser activated metallization technology uses a laser to scan a ceramic substrate to generate active centers with catalytic ability on the surface of the ceramic substrate, and then combines it with electroless plating technology to deposit metal wires with high conductivity. The process of laser modification of the surface of ceramic substrates uses the high energy of the laser beam to decompose the precursor and generate catalytic activity, in which thermal effect is the main inducement. During the electroless plating process, only the modified sites can catalyze the deposition of metal particles. Therefore, the width and edge quality of the modified area determine the fineness of the final formed conductor. In order to obtain finer metal wires, by using laser beams with shorter wavelengths in the ultraviolet and deep ultraviolet bands or optimizing optical system parameters to obtain smaller spot diameters, or by using ultra-short pulse laser beams with smaller heat-affected zones, However, these methods cannot fundamentally solve the generation of heat-affected zone at the edge of the laser spot. The decomposition of the precursor in the heat-affected zone will expand the width of the modified zone. On the other hand, the energy distribution of the commonly used laser beam is uneven and has an axis-symmetric Gaussian distribution. Therefore, only the energy in the center area of the laser spot can reach the decomposition threshold of the precursor, and the precursor near the decomposition threshold cannot be fully decomposed. , which will cause the metal wires formed by subsequent electroless plating to have sparse edges and more burrs, seriously affecting the electrical performance. In addition, the deposition of metal during the electroless plating process is an isotropic process. The metal wires on the surface of the substrate will also grow sideways while thickening, which will make the width of the final formed circuit significantly larger than the width of the laser action area. Therefore, laser-activated metallization is currently difficult to meet the manufacturing requirements of high-precision ceramic-based circuits. Although the process of inkjet printing activation material + selective electroless plating is simple, the accuracy is very poor. The line edge roughness of the conductive circuit is poor, the bonding force between the conductive circuit and the ceramic substrate is poor, the efficiency is low, and it cannot be used for high-precision ceramic circuit boards. of manufacturing.

Therefore, various existing ceramic-based circuit board manufacturing technologies cannot meet the industrial-level manufacturing requirements of low-cost, high-precision, high-efficiency, green and environmentally friendly and large-scale manufacturing of high-precision ceramic-based circuit boards. Ceramics are different from glass, PET The rough surface structure of flat surfaces such as substrates makes it difficult to directly form conductive circuits with fine line width and good surface morphology on the surface. In particular, it is impossible to realize high-precision conformal circuits on non-flat ceramic surfaces and three-dimensional curved ceramic surfaces. Manufacturing, the manufacturing of special-shaped ceramic-based circuit boards and over-sized high-precision ceramic-based circuit boards, urgently needs to develop new high-precision ceramic-based circuit manufacturing new technologies and processes.

The above information disclosed in this Background Art is only for increasing understanding of the Background Art of this application and, therefore, it may contain prior art that does not constitute prior art known to a person of ordinary skill in the art.

Contents of the invention

In order to achieve the above objects, the technical solution adopted by the present invention is:

A method for manufacturing high-precision ceramic-based circuits based on electric field-driven spray deposition micro-nano 3D printing, including the following steps:

Step 1: Ceramic substrate pretreatment: Clean, dry, and other treatments on the printed ceramic substrate to ensure that the ceramic substrate is clean and free of oil stains, dirt, etc.;

Step 2: Apply the sacrificial layer: evenly apply a layer of sacrificial layer material on the surface of the pretreated ceramic substrate and solidify the sacrificial layer;

Step 3: Micro-nano 3D printing conductive structure: According to the geometric pattern and size of the designed conductive structure, conductive ink is selected as the material for printing the conductive structure, and the electric field driven jet deposition micro-nano 3D printing process is used to coat the ceramic substrate with a sacrificial layer. Print the required conductive structure;

Step 4: Pre-curing of the conductive structure: Dry and pre-cure the conductive structure on the printed sacrificial layer of the ceramic substrate;

Step 5: Treatment of the pre-cured conductive structure: Clean and air-dry the pre-cured conductive structure, and remove dust and impurities attached to the substrate during the printing and pre-curing process;

Step 6: Sintering of the conductive structure: Place the printed conductive structure into the sintering furnace, and perform high-temperature sintering according to the set sintering temperature, time, and sintering curve. On the one hand, the sacrificial layer is completely removed, and on the other hand, the printed conductive structure is Carry out sintering conductive treatment (completely remove the organic solvent in the conductive ink), and at the same time realize the sintering of the printed conductive structure and the ceramic into one (high-temperature sintering makes the binding phase in the conductive ink and the ceramic into one, ensuring that the circuit and the ceramic have the same Very high bonding strength);

Step 7: Post-processing of the sintered conductive structure: Clean and dry the sintered conductive structure to ensure that the residue on the ceramic substrate and conductive structure during the sintering process is removed.

In some embodiments of the present application, the conductive structures are conductive lines, intra-layer and inter-layer connection circuits, or passive devices. The passive devices include resistors, inductors, capacitors, etc.

In some embodiments of the present application, the ceramic substrate in step 1 includes but is not limited to alumina ceramics, aluminum nitride ceramics, zirconia ceramics, beryllium oxide ceramics, boron nitride ceramics, etc.

In some embodiments of the present application, the sacrificial layer materials applied in step 2 include but are not limited to the following materials: aqueous coating liquid, polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA) , and other materials that can improve the surface quality of ceramics and can be removed by high temperature are also within the scope of the claims of the present invention, and water-based coating liquids are preferred.

In some embodiments of this application, the method of coating the sacrificial layer material in step 2 includes but is not limited to the following processes: spin coating, slit coating, spray coating, pull-up coating, blade coating, and casting Coating. Priority is given to slot coating.

In some embodiments of the present application, the thickness of the sacrificial layer applied in step 2 is 500 nm-20 microns.

In some embodiments of the present application, the curing method of the sacrificial layer in step 2 includes but is not limited to: heating curing, ultraviolet curing, infrared curing, laser curing, etc.

In some embodiments of the present application, the electric field-driven jet deposition micro-nano 3D printing technology in step 3 includes contact electric field-driven jet deposition micro-nano 3D printing technology, non-contact electric field-driven jet deposition micro-nano 3D printing technology, and single-phase electric field-driven jet deposition micro-nano 3D printing technology. Flat electrode electric field driven jet deposition micro-nano 3D printing technology.

In some embodiments of this application, the printing material conductive ink used in step 3 includes but is not limited to the following materials: nano silver paste, nano copper paste, and other conductive pastes containing nano metal materials to enhance the conductive structure. For the bonding force with the ceramic base, nano-silver paste containing a binding phase is preferably used, and the binding phase is glass, oxide or a mixture of the two. Nano silver paste is preferred.

In some embodiments of the present application, in step 3, by controlling the printing process parameters of electric field-driven jet deposition micro-nano 3D printing, the printing circuit accuracy (line width, line spacing), printing circuit morphology and quality ( Line edge roughness), the printing process parameters mainly include: printing nozzle (including but not limited to stainless steel nozzle, Musashi nozzle, glass nozzle, silicon nozzle, plastic nozzle, etc.) inner diameter size, voltage, printing speed, printing height (distance between nozzle and ceramic substrate), back pressure, etc. Based on the printing material and printing circuit accuracy and shape, a suitable printing process window is selected.

In some embodiments of this application, the inner diameter of the printing nozzle used in step 3 is 1-300 μm; the printing voltage is 300-3000V; the printing speed is 5-100mm/s; the printing high end is 50-500 μm; and the back pressure is 100-800kpa.

In some embodiments of the present application, in step 3, according to the thickness dimension of the circuit, the required thickness of the circuit can be obtained by using a single printing or multiple repeated printings.

In some embodiments of the present application, the pre-curing of the printed circuit in step 4 includes but is not limited to the following methods: heating curing, ultraviolet curing, infrared curing, laser curing, etc.

In some embodiments of this application, the sintering in step 5 includes but is not limited to the following processes: drying furnace sintering; vacuum sintering; inert gas sintering; during the sintering process, priority is given to flowing inert gas to separate the sacrificial layer Materials and organic solvent materials in conductive ink are discharged from the sintering furnace in a timely manner. The sintering temperature is 600-2200℃. The sintering time is 10-50 minutes.

In some embodiments of the present application, the drying methods in step 1 and step 7 include but are not limited to heating oven drying.

In some embodiments of the present application, the cleaning liquid used for cleaning in steps 1, 5 and 7 is deionized water, and the air-drying gas is an inert gas such as nitrogen.

Compared with the prior art, the present invention achieves the following beneficial effects:

The invention combines the sacrificial layer coating on the ceramic substrate and the electric field-driven spray deposition micro-nano 3D printing technology to achieve efficient and low-cost manufacturing of large-size, high-precision ceramic-based circuit boards, and provides a solution for the manufacturing and large-scale production of high-precision ceramic-based circuit boards. A disruptive technology solution.

Ceramics are different from flat surfaces such as glass and PET substrates. Its rough surface structure makes it difficult to directly form conductive lines with fine line width and good surface morphology on its surface. Therefore, the method of the present invention uses a sacrificial layer material to create good The printing environment allows the conductive lines to form a strong bonding force with the rough ceramic surface while removing the sacrificial layer material during the subsequent high-temperature sintering process.

(1) High precision. The invention realizes the manufacturing of high-precision ceramic-based circuits, can realize the manufacturing of high-precision ceramic-based circuits with line widths less than 10 microns, and especially has the potential to manufacture sub-microscale high-precision ceramic-based circuits. Currently, in addition to the photolithography + etching process that has the process capability to manufacture high-precision ceramic-based circuits with line widths less than 10 microns, there is no other technology that can achieve the manufacturing of high-precision ceramic-based circuits with line widths less than 10 microns. This invention realizes the manufacturing of high-precision ceramic-based circuits by organically combining three strategies. First, by coating a sacrificial layer, on the one hand, the flatness of the ceramic surface is improved, resulting in a more uniform distribution of polarized charges on the surface of the substrate and a more uniform electric field. Stable, thereby making the printing quality, especially the consistency of printed circuits on large-size substrates, on the other hand, the sacrificial layer is a hydrophobic material, which can help improve the accuracy of subsequent printed circuits. Subsequently, using nano conductive ink, electric field-driven jet deposition micro-nano 3D printing was used to achieve high-precision circuit manufacturing (electric field-driven jet deposition micro-nano 3D printing has the process capability of sub-microscale and nano-scale feature printing), achieving micro-scale or even sub-scale Printing of microscale circuits. Finally, through the high-temperature sintering process, the printed circuit shrinks (removal of the organic solvent in the conductive ink). If the sacrificial layer is not applied, the conductive ink will infiltrate into the ceramic substrate during the printing process, resulting in the inability to achieve overall shrinkage during the sintering process. The shrinkage rate during the sintering process is only about 10%, while the shrinkage rate of the sacrificial layer coated can reach at least 20%. If the overall shrinkage cannot be achieved, local shrinkage will cause breakpoints after sintering, which will lead to discontinuous circuits after sintering. , seriously affecting the conductivity of ceramic-based circuits, and even causing non-conductivity. The present invention further improves the accuracy of printed circuits (line reduction and width). Only through the organic collection of these strategies can high-precision ceramic-based circuit manufacturing be realized.

(2)Extra large size. The invention can realize the manufacturing of ultra-large-sized and high-precision ceramic-based circuits. The invention adopts an electric field-driven spray deposition micro-nano 3D printing process, which has the process capability of m-scale printing, and combines the adaptive adjustment of the nozzle height and the coated sacrificial layer to ensure the consistency of large-size ceramic substrate circuit printing.

(3) High-precision printing of conformal circuits on ceramic-based curved surfaces. It can realize high-precision ceramic-based circuit manufacturing on non-flat ceramic substrates and curved ceramic substrates. Combined with five-axis linkage printing technology, the present invention can realize high-precision ceramic-based circuit manufacturing on non-flat ceramic substrates and curved ceramic substrates. This is a unique technical advantage of the present invention. Various existing manufacturing technologies cannot realize the printing of high-precision conformal circuits on non-flat ceramic substrates, especially on curved ceramic substrates.

(4) High production efficiency and short production process. The existing high-precision ceramic-based circuit manufacturing method requires multiple process steps such as copper plating or copper coating on the ceramic substrate, photoresist coating, photolithography, etching, photoresist removal, and post-processing. The process is complex and cycle-intensive. long and low production efficiency. The present invention mainly adopts process steps such as coating the sacrificial layer, printing and sintering, and has a short process flow and high production efficiency.

(5) Low cost. On the one hand, the traditional manufacturing method of high-precision ceramic-based circuits based on photolithography, on the other hand, more than 90% of copper is ultimately wasted; on the other hand, expensive photolithography equipment, sputtering equipment, etc. are also required; in addition, clean rooms and vacuum are required Production conditions such as high temperature and high temperature are also relatively harsh for the production environment, resulting in very high production costs. The low production cost of the present invention is one of the biggest advantages.

(6) The printed high-precision circuit has high bonding strength with the ceramic substrate. After conductive sintering, the sacrificial layer is removed and the circuit is embedded into the rough surface of the ceramic substrate to form an interlocking structure. If the conductive ink used as printing material contains glass powder, the glass powder and ceramics will be connected into one body after sintering, resulting in higher connection strength.

(7) During the manufacturing process, there are very few waste liquids, waste gases, and waste residues, which cause little environmental pollution, and it is a green manufacturing. The traditional manufacturing method of high-precision ceramic-based circuits based on photolithography and etching will produce a large amount of waste liquid, waste gas, waste residue, etc., resulting in serious environmental pollution and seriously restricting the widespread use of this technology.

(8) High production flexibility and suitable for manufacturing requirements of different batches.

(9) The present invention can be used in the manufacture of high-precision low-temperature co-fired ceramics (LTCC).

(10) High material utilization rate. The material utilization rate of the present invention exceeds 95%, while more than 95% of materials are wasted in existing photolithography and etching processes.

(11) Combined with multi-nozzle multi-material printing, the present invention can realize integrated manufacturing of ceramic structures and electronics, and integrated manufacturing of multi-layer ceramic circuits.

Description of the drawings

The description and drawings that constitute a part of this application are used to provide a further understanding of this application. The illustrative embodiments and their descriptions of this application are used to explain this application and do not constitute an improper limitation of this application.

Figure 1 is a schematic diagram of the electric field-driven spray deposition micro-nano 3D printing high-precision ceramic-based circuit manufacturing method;

Figure 2 is an electron microscope image of the multi-layer fine linewidth circuit grid of Example 1;

Figure 3 is a real shot and an electron microscope image of the miniature PCB conductive pattern in Embodiment 2;

Among them, 1-ceramic substrate; 2-sacrificial layer; 3-printing nozzle; 4-printing circuit.

Detailed ways

It should be noted that the following detailed description is illustrative and is intended to provide explanation of some embodiments of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meanings commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular forms are also intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, it will be understood that when the terms "comprises" and/or "includes" are used in this specification, they indicate There are features, steps, operations, means, components and/or combinations thereof.

The present invention will be further described below in conjunction with the accompanying drawings and examples.

Example 1

The manufacturing method of high-precision ceramic-based circuits based on electric field-driven spray deposition micro-nano 3D printing includes: (1) using alumina ceramics, aluminum nitride ceramics, zirconia ceramics, boron nitride ceramics, beryllium oxide ceramics, etc. as carriers according to actual needs The base material of the circuit; (2) use aqueous coating liquid as a sacrificial layer to create a good printing environment; (3) use electric field-driven jet deposition micro-nano 3D printing technology, using the "necking" effect of Taylor cones to achieve various shapes , line width and aspect ratio conductive circuit production; (4) Use a high-temperature atmosphere furnace to sinter the printed sample at high temperature to remove the sacrificial layer and improve the adhesion between the conductive circuit and the ceramic substrate. (5) Combining electric field-driven spray deposition micro-nano 3D printing high-precision patterning technology and the larger shrinkage effect of the circuit after sintering, it is possible to achieve low-cost manufacturing of high-precision ceramic-based circuits. In addition, through high-temperature sintering, on the one hand, the sacrificial layer is removed, especially the organic components of the printed circuit are completely removed, so that the circuit and the surface of the rough ceramic substrate are structurally interlocked, and the glass powder and ceramic are sintered into one, which strongly improves the circuit and Joint strength of ceramic substrates.

This embodiment is based on electric field driven spray deposition micro-nano 3D printing technology, and conductive silver paste is selected to print a conductive pattern structure on a ceramic substrate. The pattern structure produced is a multi-layer fine line width grid structure. Specific preparation steps include:

Step 1: Ceramic substrate pretreatment. Use deionized water to clean the printed ceramic substrate and use nitrogen to air-dry the ceramic substrate to ensure that the ceramic substrate is clean and free of dust, impurities, etc. The ceramic substrate is a 99 alumina ceramic sheet with a size of 120mm×120mm×1mm.

Step 2: Apply the sacrificial layer. Take 20g of aqueous coating liquid and put it in a beaker. Use a spin coater to evenly spin the coating liquid on the ceramic sheet. Set the spin coating speed to 3000 r/min and the spin coating time to 50 s to obtain a sacrificial layer thickness of 1 μm. Finally, place the ceramic substrate coated with the sacrificial layer in a vacuum drying oven and cure at 70°C for 5 minutes.

Step 3: Micro-nano 3D printing of two layers of fine line width conductive grid structure.

3-1: Put 200g of conductive silver paste into a beaker, add 10g of diluent, stir ultrasonically, place at low temperature, and then put it into the printer supply module;

3-2: Write a printing program. This example effectively prints a multi-layer grid structure with a graphic structure of 100mm×100mm and a period of 0.25mm. The printing nozzle is a glass nozzle with an inner diameter of 60μm. The printing parameters are set to the printing height (nozzle and substrate Distance) 100μm, worktable moving speed 40mm/s, printing voltage 1000V, back pressure 200kPa;

3-3: Fix the printing substrate, set the printing origin, start the printing program, and the printing is completed.

Step 4: Pre-curing of printed circuit. Place the printed sample into a vacuum drying oven for pre-curing. Set the pre-curing temperature to 70 degrees and the curing time to 15 minutes.

Step 5: Clean and air-dry the printed circuit: Use deionized water to clean the pre-cured sample, and then use nitrogen to air-dry the sample to remove dust and impurities attached to the substrate during the printing and pre-curing process.

Step 6: High-temperature sintering of the printed ceramic-based circuit: Place the printed ceramic-based circuit into the sintering furnace, set the sintering temperature to 800 degrees, and the sintering time to 15 minutes. On the one hand, the sacrificial layer is completely removed, and on the other hand, the printed circuit is processed. Sintering conductive treatment (completely removes the organic solvent in the conductive silver paste), and at the same time achieves a good combination of the printed circuit and the ceramic substrate (high temperature sintering causes the conductive silver paste and the rough ceramic surface to form a "mortise and tenon" structure);

Step 7: Post-processing of printing ceramic-based circuits: Use deionized water to clean the sintered ceramic-based circuits, and then use nitrogen to air-dry to ensure that the residue, dust and impurities remaining on the ceramic substrates and circuits during the sintering process are completely removed. clean.

The final product is shown in Figure 2. The left picture is a 27X multi-layer grid electron microscope image, and the right picture is a 600X grid intersection point electron microscope image.

Example 2

This embodiment is based on electric field driven spray deposition micro-nano 3D printing technology, and conductive silver paste is selected to print a conductive pattern structure on a ceramic substrate. The pattern structure produced is a miniature PCB-like conductive pattern. Specific preparation steps include:

Step 1: Ceramic substrate pretreatment. Use deionized water to clean the printed ceramic substrate and use nitrogen to air-dry the ceramic substrate to ensure that the ceramic substrate is clean and free of dust, impurities, etc. The ceramic substrate is a 99 alumina ceramic sheet with a size of 10mm×100mm×1mm.

Step 2: Apply the sacrificial layer. Take 5g of aqueous coating liquid and put it in a beaker. Use a spin coater to evenly spin the coating liquid on the ceramic sheet. Set the spin coating speed to 1500 r/min and the spin coating time to 30 seconds to obtain a sacrificial layer thickness of 1.5 μm. Finally, place the ceramic substrate coated with the sacrificial layer in a vacuum drying oven and cure at 70 degrees for 5 minutes.

Step 3: Micro-nano 3D printing of 5-layer fine line width conductive grid structure.

3-1: Put 50g of conductive silver paste into a beaker, add 0.2g of diluent, stir ultrasonically, place at low temperature, and put it into the printer supply module;

3-2: Write a printing program. This embodiment effectively prints a miniature PCB-like conductive pattern with a graphic structure of 7mm×7mm. The printing nozzle is a glass nozzle with an inner diameter of 20μm. The printing parameters are set to a printing height (distance between nozzle and substrate) of 30μm. The worktable movement speed is 2mm/s, the printing voltage is 800V, and the back pressure is 200kPa;

3-3: Fix the printing substrate, set the printing origin, start the printing program, and the printing is completed.

Step 4: Pre-curing of printed circuit. Place the printed sample into a vacuum drying oven for pre-curing. Set the pre-curing temperature to 70 degrees and the curing time to 15 minutes.

Step 5: Clean and air-dry the printed circuit: Use deionized water to clean the pre-cured sample, and then use nitrogen to air-dry the sample to remove dust and impurities attached to the substrate during the printing and pre-curing process.

Step 6: High-temperature sintering of the printed ceramic-based circuit: Place the printed ceramic-based circuit into the sintering furnace, set the sintering temperature to 800 degrees, and the sintering time to 15 minutes. On the one hand, the sacrificial layer is completely removed, and on the other hand, the printed circuit is processed. Sintering conductive treatment (completely removes the organic solvent in the conductive silver paste), and at the same time achieves a good combination of the printed circuit and the ceramic substrate (high temperature sintering causes the conductive silver paste and the rough ceramic surface to form a "mortise and tenon" structure);

Step 7: Post-processing of printing ceramic-based circuits: Use deionized water to clean the sintered ceramic-based circuits, and then use nitrogen to air-dry to ensure that the residue, dust and impurities remaining on the ceramic substrates and circuits during the sintering process are completely removed. clean.

The final product is shown in Figure 3. The left picture is a real shot of the miniature PCB conductive pattern, and the right picture is an electron microscope image of the 36X miniature PCB conductive pattern.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the protection scope of this application.

Claims (16)

1. The manufacturing method of the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition is characterized by comprising the following steps of:

step 1: pretreatment of a ceramic substrate: cleaning and drying the ceramic substrate for printing;

step 2: coating a sacrificial layer: uniformly spreading a layer of sacrificial layer material on the surface of the pretreated ceramic substrate and curing the sacrificial layer;

step 3: micro-nano 3D printing conductive structure: according to the geometric pattern and the size of the designed conductive structure, selecting conductive ink as a material for printing the conductive structure, and adopting an electric field driven jet deposition micro-nano 3D printing process to print the required conductive structure on the ceramic substrate coated with the sacrificial layer;

step 4: pre-curing the conductive structure: drying and pre-curing the conductive structure on the printed ceramic substrate sacrificial layer;

step 5: treatment of the conductive structure after pre-curing: cleaning and drying the pre-cured conductive structure, and removing pollutants attached to the base material in the printing and pre-curing process;

step 6: sintering of the conductive structure: then placing the conductive structure into a sintering furnace, and performing high-temperature sintering according to the set sintering temperature, sintering time and sintering curve, so that on one hand, the sacrificial layer is completely removed, and on the other hand, the printed conductive structure is subjected to sintering conductive treatment, and meanwhile, the printed conductive structure and the ceramic substrate are sintered into a whole;

step 7: post-treatment of the sintered conductive structure: and cleaning and drying the sintered conductive structure to ensure that residues on the ceramic substrate and the conductive structure are removed completely in the sintering process.

2. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 1, wherein the conductive structure is a conductive line or a passive device, and the passive device comprises a resistor, an inductor and a capacitor.

3. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 1, wherein the ceramic substrate in the step 1 comprises aluminum oxide ceramic, aluminum nitride ceramic, zirconium oxide ceramic, beryllium oxide ceramic and boron nitride ceramic.

4. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven spray deposition according to claim 1, wherein the plated sacrificial layer material in the step 2 comprises: aqueous coating liquid, polydimethylsiloxane and polyvinyl alcohol.

5. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven spray deposition according to claim 1, wherein the method for paving the sacrificial layer material in the step 2 comprises the following steps: spin coating, slot coating, spray coating, pull-up coating, knife coating, and casting coating.

6. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 1, wherein the thickness of the coated sacrificial layer in the step 2 is 500nm-20 μm.

7. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 1, wherein the conductive ink used in the step 3 is a conductive paste containing nano metal materials.

8. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven spray deposition according to claim 1, wherein in the step 3, the printing process parameters of the micro-nano 3D printing are controlled to realize the precise control of the line width, the line distance, the shape and the quality of the printing circuit, and the printing process parameters comprise: printing nozzle material, nozzle inner diameter size, printing voltage, printing speed, printing height and back pressure.

9. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 1, wherein in the step 3, single printing or repeated printing is selected according to the size of the required conductive structure.

10. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 1, wherein the sintering atmosphere in the step 6 is as follows: one of air sintering, vacuum sintering, and inert gas sintering; the sintering temperature is 600-2200 ℃ and the sintering time is 10-50 minutes.

11. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven spray deposition according to claim 4, wherein the coated sacrificial layer material in the step 2 is aqueous coating liquid.

12. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven spray deposition according to claim 5, wherein the method for spreading the sacrificial layer material in the step 2 is slot coating.

13. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 7, wherein the conductive ink used in the step 3 comprises nano silver paste and nano copper paste.

14. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 7, wherein the conductive ink used in the step 3 is nano-slurry containing a bonding phase, and the bonding phase is glass, oxide or a mixture of the glass and the oxide.

15. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 8, wherein the inner diameter size of the printing nozzle used in the step 3 is 1-300 μm; printing voltage is 300-3000V; the printing speed is 5-100mm/s; printing height is 50-500 mu m; the back pressure is 100-800 kpa.

16. The method for manufacturing the micro-nano 3D printing high-precision ceramic-based circuit based on electric field driven jet deposition according to claim 10, wherein flowing inert gas is introduced to timely discharge organic solvent materials in sacrificial layer materials and conductive ink out of a sintering furnace.