Manufacturing process of high-precision circuit, high-precision circuit board and application of high-precision circuit board

Abstract

The invention discloses a manufacturing process of a high-precision circuit, a high-precision circuit board and application thereof, and belongs to the technical field of microelectronics, and the manufacturing process of the high-precision circuit comprises the following steps: printing a layer of conductive slurry on a substrate, and then sintering to form a conductive coating; and coating photoresist on the conductive coating, and then sequentially performing exposure, development, baking and etching. A circuit with the line width of 20 microns can be formed by adopting a printing and etching process, the line type precision of the circuit can be remarkably improved, and the manufacturing process is simpler. Therefore, the problems that an existing circuit manufacturing process is complex in process and low in circuit linear precision can be solved.

Description

Technical Field

[0001] This invention relates to the field of microelectronics technology, and in particular to a manufacturing process for high-precision circuits, high-precision circuit boards, and their applications. Background Technology

[0002] There are two main methods for manufacturing conventional circuits: direct printing and thin-film technology. Circuits formed by direct screen printing are relatively rough and the line accuracy is not high enough; while the process of manufacturing circuits using thin-film technology is complicated. Summary of the Invention

[0003] The main objective of this invention is to propose a manufacturing process for high-precision circuits, a high-precision circuit board, and its applications, aiming to solve the problems of complex manufacturing processes and low precision of circuit lines in existing systems.

[0004] To achieve the above objectives, the present invention provides a manufacturing process for high-precision circuits, comprising:

[0005] A layer of conductive paste is printed on the substrate, and then sintered to form a conductive coating.

[0006] Photoresist is applied to the conductive coating, followed by exposure, development, baking, and etching.

[0007] In one embodiment, the etching solution used in the etching step includes elemental iodine, potassium iodide, concentrated hydrochloric acid and water, with the mass ratio of elemental iodine, potassium iodide, concentrated hydrochloric acid and water being (3-5):(4-6):(2-5):(130-140); and / or, the temperature of the etching step is 25℃-40℃ and the time is 5min-15min.

[0008] In one embodiment, the conductive paste comprises the following components by weight percentage:

[0009] Metal powder 80%-95%, matrix resin 1%-4%, glass powder 0.3%-3%, inorganic additives 0.1%-0.3%, dispersant 0.05%-0.3%, plasticizer 0.1%-1%, auxiliary agents 0.1%-0.4%, and the balance is organic solvent.

[0010] In one embodiment, the metal powder is selected from at least one of gold powder, silver powder, platinum powder, and palladium powder; and / or,

[0011] The matrix resin comprises acrylic resin and ethyl cellulose, wherein the mass ratio of acrylic resin to ethyl cellulose is (0.2-1):(0.8-3); and / or,

[0012] The glass powder comprises the following components by weight percentage: 30%-50% silica, 15%-30% boric acid, 5%-15% titanium dioxide, 8%-15% calcium oxide, 5%-10% molybdenum oxide, and 2%-10% sodium carbonate; and / or,

[0013] The inorganic additive is selected from at least one of bismuth oxide, copper oxide, and zinc oxide; and / or,

[0014] The dispersant is selected from at least one of silane coupling agents and organic acids; and / or,

[0015] The plasticizer is selected from at least one of tributyl citrate, dibutyl phthalate, and dioctyl adipate; and / or,

[0016] The additives are selected from at least one of thixotropic agents, leveling agents, and defoamers; and / or,

[0017] The organic solvent is selected from at least one of diethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, dodecyl alcohol ester, propylene glycol methyl ether, dipropylene glycol methyl ether, turpentine oil, and terpineol.

[0018] In one embodiment, the printing thickness of the conductive paste is 4μm-5μm; and / or, the coating thickness of the photoresist is 1μm-3μm.

[0019] In one embodiment, the sintering step is performed at a temperature of 800°C-900°C for 5 min-30 min; and / or the baking step is performed at a temperature of 110°C-140°C for 20 min-40 min.

[0020] In one embodiment, the exposure step uses ultraviolet light exposure with an exposure energy of 500mJ-2000mJ.

[0021] In one embodiment, the developing solution used in the developing step is an alkaline solution.

[0022] The present invention also provides a high-precision circuit board, which is manufactured by the above-described manufacturing process.

[0023] The present invention also provides the application of the above-mentioned high-precision circuit board in filters.

[0024] The manufacturing process of this invention includes sequential steps of printing gold paste, sintering, coating photoresist, exposure, development, baking, and etching. Specifically, this invention uses a printing and etching process to form circuits with line widths of 20 μm, compared to line widths exceeding 80 μm formed by direct printing. This invention significantly improves the linear accuracy of the circuit. Furthermore, compared to thin-film processes requiring physical vapor deposition and electroplating, the manufacturing process of this invention is simpler. Therefore, this invention solves the problems of complex processes and low linear accuracy in existing circuit manufacturing processes. Detailed Implementation

[0025] It should be noted that if the embodiments of the present invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the use of "and / or" or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied. In the embodiments of the present invention, "at least one" refers to one or more, and "more" refers to two or more.

[0026] In this invention, the "range" is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is understood that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this invention, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0027] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] Conventional circuit fabrication processes mainly include two methods: direct printing and thin-film deposition. Direct printing involves screen printing circuits, followed by sintering to form conductive lines. Circuits produced by this process are relatively coarse, with line widths exceeding 80μm and insufficient line precision. Thin-film deposition, on the other hand, requires physical vapor deposition and electroplating on a substrate, which presents a complex process.

[0029] Therefore, the present invention provides a manufacturing process for high-precision circuits, comprising the following steps:

[0030] A layer of conductive paste is printed on the substrate, and then sintered to form a conductive coating.

[0031] Photoresist is applied to the conductive coating, followed by exposure, development, baking, and etching.

[0032] Conductive paste refers to a paste containing metal powder. The metal powder has excellent conductivity and chemical stability, which can form highly reliable electronic connections.

[0033] Printing can be done using screen printing or stencil printing, with the aim of precisely printing the conductive paste onto designated locations on the substrate. After printing, the substrate needs to be dried in air to remove some of the solvent and moisture before being placed in a high-temperature furnace for sintering. During sintering, the organic carrier in the conductive paste is burned off, and the glass powder in the conductive paste melts and binds the metal powder particles together, forming a conductive metal connection.

[0034] Photoresist is a chemical substance that is sensitive to light. After coating the photoresist, exposure allows the circuit pattern to be transferred onto the photoresist. Development then allows the exposed areas of the photoresist to dissolve (positive photoresist), while the unexposed areas remain on the substrate, or development dissolves the unexposed areas of the photoresist (negative photoresist), while the exposed areas remain on the substrate, thus forming a conductive pattern on the substrate. Baking further enhances the reaction of the photoresist through heating. Finally, etching aims to selectively remove or modify the substrate material according to the pattern formed by the photoresist to create the desired microstructure.

[0035] After etching, a stripping step is included, specifically removing the photoresist layer by immersing the substrate in the stripping solution to fully dissolve the photoresist. The stripping solution is used in conjunction with the photoresist.

[0036] This invention employs a printing and etching process to form circuits with line widths of 20 μm, compared to line widths exceeding 80 μm formed by direct printing. This significantly improves the linear accuracy of the circuit. Furthermore, compared to thin-film processes requiring physical vapor deposition and electroplating, the fabrication process of this invention is simpler. Therefore, this invention solves the problems of complex processes and low linear accuracy in existing circuit fabrication methods.

[0037] In an embodiment of the present invention, the etching solution used in the etching step includes elemental iodine, potassium iodide, concentrated hydrochloric acid and water, and the mass ratio of elemental iodine, potassium iodide, concentrated hydrochloric acid and water is (3-5):(4-6):(2-5):(130-140).

[0038] Elemental iodine (I₂) serves as the primary etchant. Its oxidizing properties allow it to oxidize metal atoms in the conductive paste, causing them to lose electrons and form metal cations. These metal cations then react with iodide ions (I₂) in the solution. - They combine to form soluble metal iodide complexes. Elemental iodine provides the oxidizing power needed to dissolve metal atoms from a solid substrate.

[0039] Potassium iodide (KI), acting as a complexing agent and solubilizer, primarily provides a large amount of iodide ions (I₂). - ), iodide ions (I - It can form soluble complexes with metal cations produced by I2 oxidation. The complexation effect greatly improves the solubility of the metal in the solution, enabling it to be effectively removed and preventing insoluble substances from depositing on the substrate or edge of the pattern, thus affecting the etching accuracy and surface quality.

[0040] Concentrated hydrochloric acid refers to a 36.6% hydrochloric acid solution. It provides an acidic environment, which is crucial for successful etching. This acidic environment prevents metal ions from hydrolyzing to form insoluble hydroxides or oxides. These precipitates can clog the etching process, leading to rough surfaces and uneven etching. Furthermore, concentrated hydrochloric acid contains chloride ions (Cl...). - It also plays a role in assisting complexation and optimizing etching performance.

[0041] In embodiments of the present invention, the etching step is performed at a temperature of 25°C-40°C for 5-15 minutes. Excessive temperature will result in too rapid etching, leading to side etching problems; excessively low temperature will result in incomplete etching and low etching efficiency.

[0042] In this embodiment of the invention, the printing thickness of the conductive paste is 4μm-5μm. That is, this embodiment is a thick-film printing process to form a thick-film circuit.

[0043] In embodiments of the present invention, the conductive paste comprises the following components by mass percentage:

[0044] Metal powder 80%-95%, matrix resin 1%-4%, glass powder 0.3%-3%, inorganic additives 0.1%-0.3%, dispersant 0.05%-0.3%, plasticizer 0.1%-1%, auxiliary agents 0.1%-0.4%, and the balance is organic solvent.

[0045] Metal powders are used to improve the conductivity required for conductive pastes.

[0046] The matrix resin, acting as a carrier, can bind other components in the conductive paste. During printing and drying, it helps maintain the predetermined shape and size of the conductive coating. The rheological properties of the matrix resin also improve the printability of the conductive paste. In addition, during sintering, the matrix resin helps control the sintering behavior of the metal powder, preventing excessive sintering and creep of the metal powder particles, and maintaining the conductivity and other electrical properties of the conductive coating.

[0047] Glass powder and inorganic additives act as binders, melting and filling the spaces between metal powder, matrix resin, and other components during sintering, promoting adhesion and ensuring the circuit maintains structural integrity under high temperatures and mechanical stress. Dispersants help to uniformly disperse metal powder and other components, improving the consistency of the conductive paste.

[0048] Plasticizers and additives exist as auxiliary additives. Plasticizers can improve the fluidity of conductive paste, making it easier to print the conductive paste onto the substrate through screen printing. The addition of plasticizers can also improve the flexibility and ductility of the conductive coating after it is formed, so that it can withstand mechanical stress and thermal cycling.

[0049] In embodiments of the present invention, the metal powder is selected from at least one of gold powder, silver powder, platinum powder, and palladium powder; and / or, the matrix resin includes acrylic resin and ethyl cellulose, wherein the mass ratio of acrylic resin to ethyl cellulose is (0.2-1):(0.8-3); and / or, the inorganic additive is selected from at least one of bismuth oxide, copper oxide, and zinc oxide; and / or, the dispersant is selected from at least one of silane coupling agent and organic acid; and / or, the plasticizer is selected from at least one of tributyl citrate, dibutyl phthalate, and dioctyl adipate; and / or, the auxiliary agent is selected from at least one of thixotropic agent, leveling agent, and defoamer; and / or, the organic solvent is selected from at least one of diethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, dodecyl alcohol ester, propylene glycol methyl ether, dipropylene glycol methyl ether, turpentine oil, and terpineol.

[0050] Spherical metal powder can be selected. Spherical metal powder has good dispersibility in slurry, which helps to form a uniform conductive coating. Furthermore, spherical metal powder helps to reduce the contact resistance between electrons and particles, thereby improving the conductivity of the conductive coating.

[0051] Acrylic resin refers to a polymer compound formed by the polymerization reaction of acrylic monomers or their derivatives. Ethyl cellulose is a polymer material obtained by introducing ethyl groups onto cellulose molecules. Using a mixture of acrylic resin and ethyl cellulose as the matrix resin can not only improve the printability of the paste, but also facilitate its loss of volatility during sintering.

[0052] Limiting the mass ratio of acrylic resin to ethyl cellulose to (0.2-1):(0.8-3) ensures good dispersibility and printability of metal powder and other inorganic powders, improving sintering consistency. It also ensures good debinding properties of the conductive paste during sintering, thereby reducing defects in the sintering process.

[0053] Among inorganic additives, bismuth oxide, as a low-melting-point oxide, can act as a flux to lower the sintering temperature and promote the melting and bonding of other components during the printing and sintering process of conductive pastes to form conductive coatings. Furthermore, bismuth oxide can improve the conductivity and chemical stability of conductive pastes. Copper oxide and zinc oxide are mainly used to improve the conductivity of conductive pastes; in addition, copper oxide and zinc oxide can also act as sintering accelerators, helping to lower the sintering temperature of conductive pastes.

[0054] Silane coupling agents are chemical agents containing two groups with different chemical properties. One group reacts with inorganic substances (metal powder, glass powder, inorganic additives), while the other reacts with organic substances (matrix resin, plasticizer, auxiliaries, organic solvents). This allows inorganic substances such as metal powder to be uniformly dispersed in the slurry, improving the consistency of the slurry. Organic acids are chemical agents containing carboxyl groups. Their carboxyl groups can react with inorganic substances (metal powder, glass powder, inorganic additives) to form stable chemical bonds. The organic portion of the organic acid (aliphatic chains, etc.) can interact with organic substances (matrix resin, plasticizer, auxiliaries, organic solvents) through van der Waals forces, hydrogen bonds, or covalent bonds. Therefore, organic acids can also help to uniformly disperse inorganic substances such as gold powder, thereby improving the consistency of the slurry.

[0055] The silane coupling agent is selected from at least one of KH-550, KH-560, KH-570, KH-792, KH-2121, KH-2122, GPTES, APTES, VTMS, VTES, and JH-N308. The organic acid is selected from at least one of citric acid, malic acid, tartaric acid, acetic acid, butyric acid, valeric acid, hexanoic acid, mercaptoacetic acid, and mercaptopropionic acid.

[0056] Thixotropic agents are mainly used to improve the thixotropic properties of conductive pastes. Under external force (such as stirring or shearing), the viscosity of the conductive paste decreases and its fluidity increases; when the external force is removed, the viscosity of the conductive paste quickly returns to normal, and its fluidity decreases. This characteristic allows the conductive paste to flow easily during printing, while maintaining a certain shape and stability in a static state. Organic thixotropic agents can be selected, such as polyamide wax powder thixotropic agents, polyurea thixotropic agents, modified castor oil thixotropic agents, etc. For example, the thixotropic agent can be selected from at least one of BYK-410, BYK-405, and RHEOBYK-7420.

[0057] Leveling agents are mainly used to improve the flowability and spreadability of conductive paste on the substrate surface, ensuring that the conductive paste can be evenly distributed and dried after printing, thereby obtaining a smooth, defect-free coating. The leveling agent can be a silicone leveling agent; for example, the leveling agent can be selected from at least one of BYK-333, BYK-345, BYK-306, BYK-358N, and BYK-361N.

[0058] Defoamers are primarily used to help eliminate or reduce air bubbles in conductive pastes to ensure the quality and uniformity of the conductive coating. Defoamers can be silicone-based; for example, the defoamer can be selected from at least one of BYK-012, BYK-014, BYK-1794, BYK-A550, and BYK-066N.

[0059] In embodiments of the present invention, the glass powder comprises the following components by mass percentage:

[0060] 30%-50% silicon dioxide, 15%-30% boric acid, 5%-15% titanium dioxide, 8%-15% calcium oxide, 5%-10% molybdenum oxide, and 2%-10% sodium carbonate.

[0061] Among them, silicon dioxide forms the basic framework, which can ensure the mechanical strength and chemical stability of glass powder; titanium dioxide can further improve the chemical stability of glass powder, thereby improving the development performance of the slurry; molybdenum oxide can give glass powder good wettability and spreadability at high temperatures.

[0062] The glass powder in this embodiment can provide good adhesion to the substrate, promote the sintering and densification of the metal powder, and at the same time, the glass powder has good acid resistance, thus having good etching resistance.

[0063] In embodiments of the present invention, the sintering temperature is 800℃-900℃, and the time is 5min-30min. Under these conditions, the organic carrier in the conductive paste can be burned off, and the glass powder in the conductive paste can melt and bind the gold powder particles together, thereby forming a conductive metal connection.

[0064] In embodiments of the present invention, the photoresist coating thickness is 1μm-3μm. If the photoresist is too thin, it will not provide protection during the exposure and development steps; if it is too thick, residual photoresist may occur, leading to incomplete etching.

[0065] Photoresist can be applied using a spin coating method. Specifically, the substrate is placed on a rotating device, and photoresist is dropped onto the center of the substrate. The rotating device is then activated to make the substrate rotate at a certain speed. As the substrate rotates, the photoresist is evenly dispersed onto the substrate surface under centrifugal force. Commercially available positive photoresist is used.

[0066] In an embodiment of the present invention, the exposure step uses ultraviolet light exposure with an exposure energy of 500mJ-2000mJ.

[0067] This embodiment uses ultraviolet light exposure with a wavelength of 300nm-436nm based on the photosensitivity of the photoresist. Since the photoresist in this embodiment is a positive photoresist, it becomes soluble in the developer under ultraviolet light irradiation. During the exposure process, the transparent parts of the mask allow ultraviolet light to pass through, while the blocking parts prevent ultraviolet light from irradiating the photoresist underneath, thereby forming the pattern on the mask on the photoresist.

[0068] Exposure energy refers to the total energy of light received by the photoresist per unit area, usually expressed in millijoules (mJ). This invention limits the exposure energy to between 500mJ and 2000mJ, which can avoid pattern distortion on the photoresist.

[0069] In embodiments of the present invention, the developing solution used in the developing step is an alkaline solution.

[0070] Since the photoresist used in this embodiment of the invention is a positive photoresist, the developer in this embodiment is an alkaline solution that can dissolve the exposed photoresist areas. Specifically, the developer can be a sodium hydroxide solution, a trisodium phosphate solution, or a tetramethylammonium hydroxide solution, with the sodium hydroxide solution having a mass concentration range of 0.1%-1%.

[0071] In embodiments of the present invention, the baking temperature is 110°C-140°C, and the time is 20-40 minutes. If the baking temperature is too low, the etching is prone to edge peeling, while if the temperature is too high, it will lead to difficulty in removing the film.

[0072] The present invention also provides a high-precision circuit board, which is manufactured by the above-described manufacturing process.

[0073] This invention also provides the application of the aforementioned high-precision circuit board in filters. The high-precision circuit board of this invention enables product miniaturization and multifunctionality, and possesses high reliability, making it suitable for applications in fields with high reliability requirements, such as military radio frequency and high-frequency wireless communication.

[0074] The following description is based on specific embodiments.

[0075] Example 1

[0076] A manufacturing process for a high-precision circuit includes the following steps:

[0077] (1) A layer of conductive paste is screen printed on an alumina ceramic substrate. The thickness of the conductive paste is 4μm. After the conductive paste dries, the substrate with the conductive paste is placed in a high-temperature furnace for sintering. The sintering temperature is 800℃ and the sintering time is 30min. After sintering, a conductive coating is formed.

[0078] (2) A photoresist with a thickness of 1 μm was applied to the conductive coating by spin coating. Then the mask was precisely aligned with the substrate coated with photoresist, and ultraviolet light was turned on for exposure treatment with an exposure energy of 500 mJ.

[0079] (3) After exposure, the substrate was developed using a sodium hydroxide solution with a mass concentration of 0.1%. After development, the substrate was baked at 120°C for 30 minutes.

[0080] (4) The substrate after baking is etched with an etching solution at a temperature of 30°C for 10 minutes.

[0081] (5) Immerse the substrate after each step (4) in the stripping solution to remove the film.

[0082] The conductive paste comprises the following components by mass percentage:

[0083] The composition includes 85% gold powder, 0.2% acrylic resin, 0.8% ethyl cellulose, 0.3% glass powder, 0.1% bismuth oxide, 0.1% copper oxide, 0.1% zinc oxide, 0.3% KH-570, 0.1% tributyl citrate, 0.05% BYK-410, 0.05% BYK-333, 0.05% BYK-012, and 12.85% diethylene glycol butyl ether acetate.

[0084] Glass powder comprises the following components by weight percentage:

[0085] 40% silicon dioxide, 20% boric acid, 10% titanium dioxide, 10% calcium oxide, 10% molybdenum oxide, and 10% sodium carbonate.

[0086] The etching solution consists of elemental iodine, potassium iodide, concentrated hydrochloric acid, and water, with a mass ratio of 3.7:4.8:2.9:138.

[0087] The photoresist is a purchased product with the product name RZJ-304, and the stripping solution is a purchased product with the product name RBL-3316.

[0088] Example 2

[0089] Unlike Example 1, in this example, the etching temperature is controlled at 40°C in step (4), while the remaining steps are the same as in Example 1.

[0090] Example 3

[0091] Unlike Example 1, in this example, the etching temperature is controlled at 25°C in step (4), while the remaining steps are the same as in Example 1.

[0092] Example 4

[0093] Unlike Example 1, in this example, the etching time in step (4) is controlled to be 15 minutes, and the remaining steps are the same as in Example 1.

[0094] Example 5

[0095] Unlike Example 1, in this example, the etching time in step (4) is controlled to be 5 minutes, and the remaining steps are the same as in Example 1.

[0096] Comparative Example

[0097] Multiple rows of fine lines were screen-printed on an alumina substrate, with a printing thickness of 4 μm. After baking at 120°C for 10 min, the substrate was sintered in a high-temperature furnace at 800°C for 30 min. The composition of the conductive paste used for the fine lines was the same as in Example 1.

[0098] Performance testing

[0099] The line width and spacing of the circuit patterns obtained in Examples 1-5 and the comparative examples were measured, specifically by two-dimensional measurement under a microscope. The results are shown in Table 1.

[0100] Table 1 shows the line widths of patterns in Examples 1-5 and comparative examples.

[0101]

[0102] As can be seen from Table 1, the manufacturing process of this application embodiment can form a circuit with a line width of about 20μm, which can significantly improve the line accuracy compared with conventional screen printing process.

[0103] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A manufacturing process for a high-precision circuit, characterized in that, include: A layer of conductive paste is printed on the substrate, and then sintered to form a conductive coating. Photoresist is applied to the conductive coating, followed by exposure, development, baking, and etching.

2. The manufacturing process of the high-precision circuit as described in claim 1, characterized in that, The etching step uses an etching solution comprising elemental iodine, potassium iodide, concentrated hydrochloric acid, and water, wherein the mass ratio of elemental iodine, potassium iodide, concentrated hydrochloric acid, and water is (3-5):(4-6):(2-5):(130-140); and / or, The etching step is performed at a temperature of 25℃-40℃ for 5 min-15 min.

3. The manufacturing process of the high-precision circuit as described in claim 1, characterized in that, The conductive paste comprises the following components by weight percentage: Metal powder 80%-95%, matrix resin 1%-4%, glass powder 0.3%-3%, inorganic additives 0.1%-0.3%, dispersant 0.05%-0.3%, plasticizer 0.1%-1%, auxiliary agents 0.1%-0.4%, and the balance is organic solvent.

4. The manufacturing process of the high-precision circuit as described in claim 3, characterized in that, The metal powder is selected from at least one of gold powder, silver powder, platinum powder, and palladium powder; and / or, The matrix resin comprises acrylic resin and ethyl cellulose, wherein the mass ratio of acrylic resin to ethyl cellulose is (0.2-1):(0.8-3); and / or, The glass powder comprises the following components by weight percentage: 30%-50% silicon dioxide, 15%-30% boric acid, 5%-15% titanium dioxide, 8%-15% calcium oxide, 5%-10% molybdenum oxide, and 2%-10% sodium carbonate; and / or, The inorganic additive is selected from at least one of bismuth oxide, copper oxide, and zinc oxide; and / or, The dispersant is selected from at least one of silane coupling agents and organic acids; and / or, The plasticizer is selected from at least one of tributyl citrate, dibutyl phthalate, and dioctyl adipate; and / or The additive is selected from at least one of thixotropic agents, leveling agents, and defoamers; and / or, The organic solvent is selected from at least one of diethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, dodecyl alcohol ester, propylene glycol methyl ether, dipropylene glycol methyl ether, turpentine oil, and terpineol.

5. The manufacturing process of the high-precision circuit as described in any one of claims 1 to 4, characterized in that, The conductive paste is printed to a thickness of 4μm-5μm; and / or, The coating thickness of the photoresist is 1μm-3μm.

6. The manufacturing process of the high-precision circuit as described in any one of claims 1 to 4, characterized in that, The sintering step is performed at a temperature of 800℃-900℃ for a time of 5 min-30 min; and / or, The baking process is carried out at a temperature of 110℃-140℃ for 20min-40min.

7. The manufacturing process of the high-precision circuit as described in any one of claims 1 to 4, characterized in that, The exposure step uses ultraviolet light exposure with an exposure energy of 500mJ-2000mJ.

8. The manufacturing process of the high-precision circuit as described in any one of claims 1 to 4, characterized in that, The developing solution used in the developing step is an alkaline solution.

9. A high-precision circuit board, characterized in that, It is manufactured using the manufacturing process described in any one of claims 1 to 8.

10. The application of the high-precision circuit board as described in claim 9 in a filter.

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