Inkjet mask-based high-precision etching method and apparatus for ceramic circuit boards

Abstract

This invention discloses a high-precision etching method and equipment for ceramic circuit boards based on inkjet masks, belonging to the field of ceramic circuit board manufacturing technology. The invention uses a multi-point adsorption mechanism to fix the circuit board under vacuum negative pressure, and a laser alignment system to perform high-precision scanning and identification of reference marks. This drives the three-axis fine-tuning of the alignment accuracy of the support platform, ensuring precise alignment between the inkjet pattern and the substrate, avoiding pattern misalignment caused by positioning deviations. Interlaced scanning and real-time monitoring of printing quality are employed, with online reprinting for broken lines and exposed copper defects, ensuring high precision and high quality of mask pattern printing. This effectively improves the mask's shielding effect and etching resistance. The support platform can precisely coordinate with the operation of the positioning components and inkjet mask module. Combined with the ink supply constant temperature conduit and infrared detection probe, real-time quality monitoring and reprinting are achieved, ensuring high-precision printing of the mask pattern and significantly improving the automation, processing accuracy, and production efficiency of ceramic circuit board etching.

Description

Technical Field

[0001] This invention relates to the field of ceramic circuit board manufacturing technology, and in particular to a high-precision etching method and equipment for ceramic circuit boards based on inkjet masks. Background Technology

[0002] Traditional ceramic circuit board etching technologies primarily employ photolithography and laser etching. Photolithography relies on multiple processes such as photoresist coating, exposure, and development, resulting in a complex process flow, high mask manufacturing costs, and limitations in pattern resolution due to the limitations of photolithography equipment. This makes it difficult to meet the demands of micron-level fine circuit processing, and the large amount of chemical reagents used can cause environmental pollution. While laser etching can achieve high processing precision, it suffers from drawbacks such as a large heat-affected zone, susceptibility to microcracks on the material surface, and low processing efficiency. In complex pattern processing, it is prone to quality issues such as rough edges and line distortion. Furthermore, existing technologies generally lack real-time monitoring and precise control of process parameters during etching, leading to poor consistency in etching depth and pattern dimensions, making it difficult to improve product yield and meet the high-precision, high-efficiency, and high-reliability production requirements of high-end electronics manufacturing for ceramic circuit boards. Summary of the Invention

[0003] The purpose of this invention is to provide a high-precision etching method and equipment for ceramic circuit boards based on inkjet masks, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a high-precision etching method for ceramic circuit boards based on inkjet masks, comprising:

[0005] Step 1: Wash the ceramic circuit board to be processed by spraying with a combination of high-purity water and inorganic cleaning agent and then dry it, strictly controlling the concentration, time and temperature parameters of the cleaning solution;

[0006] Step 2: Place the cleaned ceramic circuit board on the support platform and align the graphic reference using laser alignment. Start the inkjet mask module and print the graphic inkjet mask on the surface of the ceramic circuit board according to the input graphic file. During the printing process, control the nozzle ejection frequency, printing speed, line width and dot density.

[0007] Step 3: After printing, the ink is initially cured using a UV curing unit, which uses a high-energy UV light source to promote the rapid formation of a hard film on the ink surface.

[0008] Step 4: Transfer the ceramic circuit board that has been cured by the mask to the etching tank assembly. Select the etching solution according to the etching requirements and set the etching time, liquid temperature and ultrasonic vibration intensity. During the etching process, selectively etch the areas not covered by the mask.

[0009] Step 5: After etching is completed, the ceramic circuit board is sent to the cleaning and drying module. The mask pattern is dissolved by the mask remover, and the removal process is accelerated by ultrasonic assistance. After the removal process is completed, the board surface is cleaned by spraying pure water and dried by hot air circulation.

[0010] Furthermore, step one specifically includes:

[0011] Deionized water is used as the high-purity water raw material. The inorganic cleaning agent is a 5%-10% sodium hydroxide and sodium carbonate mixed solution with a mass ratio of sodium hydroxide to sodium carbonate of 3:2. The cleaning solution is prepared by mixing high-purity water and inorganic cleaning agent in a volume ratio of 9:1. The temperature of the mixed solution is controlled at 40-50℃, the stirring speed is 200-300 rpm, and the stirring is continued for 15-20 minutes to ensure that the cleaning solution is mixed evenly.

[0012] The prepared cleaning solution is sprayed bidirectionally onto the ceramic circuit board at a pressure of 0.3-0.5 MPa for 8-12 minutes, while maintaining the cleaning solution temperature at 45±2℃. After the cleaning is completed, the ceramic circuit board is transferred to a hot air drying oven with a hot air temperature of 80-90℃, a wind speed of 1.5-2.0 m / s, and a drying time of 15-20 minutes to ensure that the residual moisture on the surface of the ceramic circuit board is completely evaporated and that the temperature difference between the surface of the circuit board and the ambient temperature does not exceed 5℃.

[0013] Furthermore, step two specifically includes:

[0014] The ceramic circuit board is placed in the positioning area of ​​the support platform, and the multi-point adsorption mechanism is activated to fix the ceramic circuit board under a vacuum negative pressure of -0.08 to -0.1MPa. Then, the laser alignment system is triggered, and a green laser with a wavelength of 532nm is used to scan and identify the cross-shaped or circular reference marks with a diameter of 0.1-0.3μm on the ceramic circuit board. The position deviation is calculated by the image recognition algorithm, and the support platform is driven to perform three-axis fine adjustment.

[0015] Based on the characteristics of the input graphic file, the preset inkjet process parameter group is called, and the printhead ejection frequency is set to 20-50kHz, the printing speed to 50-100μm / s, the line width control accuracy to ±3μm, and the dot matrix density to 300-1200DPI.

[0016] UV-curable mask ink is delivered to the printhead assembly, with the ink supply pressure maintained at 0.2-0.4 MPa and the temperature controlled at 30±2℃. Graphics are printed using an interlaced scanning method, and the print quality is monitored in real time during the printing process. Defects such as broken lines and exposed copper are repaired online.

[0017] Furthermore, the system monitors print quality in real time during the printing process and issues alarms when print quality is abnormal, including:

[0018] The number of broken lines and the length of missing lines corresponding to the location of the broken lines are monitored in real time during the printing process.

[0019] The total value of the missing length of the broken line is obtained according to the missing length of the broken line corresponding to the broken line location during each printing process.

[0020] The ratio of the total length of the broken lines to the total length of the printing thread is calculated to obtain the length ratio coefficient between the total length of the broken lines and the total length of the printing thread.

[0021] Filter the locations of broken wires;

[0022] The missing length of the broken line at each broken line location is compared with the preset broken line length threshold.

[0023] Filter out the locations of broken lines whose missing length exceeds a preset broken line length threshold, and use them as target broken line locations;

[0024] Based on the target break location, obtain the straight-line distance between the center points of the break between any two target break locations;

[0025] The length ratio coefficient between the total length of the missing lines and the total length of the printing thread is used in conjunction with the straight-line distance between the center points of the missing lines at every two target missing line locations to determine whether the printing quality of the current printing process meets the quality requirements, and an abnormal alarm is issued when the printing quality of the current printing process does not meet the quality requirements.

[0026] Furthermore, the ratio coefficient between the total length of missing lines and the total length of the printing thread, combined with the straight-line distance between the center points of the missing lines at every two target missing line locations, is used to determine whether the printing quality of the current printing process meets the quality requirements, including:

[0027] The printing area is divided into grids according to the preset grid size to obtain multiple grid areas corresponding to the printing area;

[0028] Extract the number of broken lines corresponding to each grid region;

[0029] The standard deviation of the number of broken lines in multiple grid regions corresponding to the printing area is obtained based on the number of broken lines appearing in each grid region.

[0030] The standard deviation of the number of broken wires is normalized to obtain the normalized standard deviation of the number of broken wires.

[0031] Extract the length ratio coefficient between the total length of broken or missing lines and the total length of the printing thread;

[0032] Extract the straight-line distance between the center points of the broken lines at every two target broken line locations;

[0033] The straight-line distance between the center points of the broken lines at every two target broken line locations is normalized using a preset straight-line distance reference value to obtain the normalized straight-line distance; wherein the preset straight-line distance reference value has a range of 1.27D. max -1.53D max And, D max This represents the maximum straight-line distance between the center points of any two target break points;

[0034] The print quality coefficient is obtained using the normalized standard deviation of the number of broken lines, the length ratio coefficient, and the normalized straight-line distance.

[0035] The print quality coefficient is compared with a preset print quality coefficient threshold.

[0036] When the print quality coefficient is lower than the preset print quality coefficient threshold, it is determined that the print quality of the current printing process does not meet the quality requirements.

[0037] Furthermore, step three specifically includes:

[0038] The inkjet-printed ceramic circuit board is fed into the UV curing unit via a carrier platform. A multi-band high-energy UV light source is turned on, and the ceramic circuit board passes through the light source at a transmission speed of 2-5 m / min. The curing time for each pass is controlled at 3-8 seconds, so that a hard film with a hardness of ≥2H is quickly formed on the surface of the mask ink, which inhibits ink diffusion.

[0039] After initial curing, the ceramic circuit board is transferred to the thermosetting auxiliary module. The module temperature is set to 120-150℃, the heating rate is controlled at 5-10℃ / min, and the temperature is maintained for 15-30 minutes to improve the adhesion and etching resistance between the mask pattern and the surface of the ceramic circuit board.

[0040] Microscopic inspection is performed on the cured mask pattern to check the edge clarity, surface flatness, and presence of bubbles or cracks. Areas with edge deviation >2μm, roughness Ra >0.5μm, or presence of bubbles or cracks are automatically marked as unqualified areas and returned to the UV curing unit for secondary curing.

[0041] Furthermore, step four specifically includes:

[0042] The etching solution is injected into the corrosion-resistant tank, and the temperature of the etching solution is adjusted to 45-65℃ by the constant temperature control unit. The vibration frequency of the ultrasonic exciter is set to 20-40kHz, and the power density is 0.5-1.5W / cm².

[0043] The ceramic circuit board with the mask cured is vertically immersed in the etching solution, and the etching solution is circulated at a flow rate of 0.5-1.5m / s. At the same time, the ultrasonic vibration source is turned on. For patterns with a line width ≥50μm, the etching time is controlled at 5-10 minutes; for fine patterns with a line width <50μm, the etching time is controlled at 3-8 minutes.

[0044] During the etching process, the concentration of the etching solution is monitored. When the concentration of the main component of the etching solution fluctuates by more than ±5%, the concentrate is automatically added for adjustment.

[0045] The etching depth of the non-mask-covered area is monitored in real time using a laser reflective thickness gauge. When the preset etching depth is reached, the ceramic circuit board is removed from the etching tank and quickly transferred to the cleaning tank for spray cleaning. The cleaning water pressure is 0.2-0.4MPa and the cleaning time is 2-5 minutes to terminate the etching reaction and remove the residual etching solution on the surface.

[0046] Furthermore, step five specifically includes:

[0047] The etched ceramic circuit board is immersed in a demasking solution tank. The demasking solution is a potassium carbonate aqueous solution with a mass concentration of 15%-25% and the temperature is controlled at 50-60℃. At the same time, the ultrasonic auxiliary device is turned on, the ultrasonic frequency is set to 40-60kHz, and the power density is 0.3-0.8W / cm².

[0048] The immersion time of the ceramic circuit board is adjusted according to the mask thickness. When the mask thickness is ≤10μm, the immersion time is controlled at 3-5 minutes; when the mask thickness is >10μm, the immersion time is controlled at 5-8 minutes, until the mask pattern is completely dissolved and detached from the ceramic circuit board surface.

[0049] The ceramic circuit board after mask removal was ultrasonically cleaned with deionized water at a frequency of 30-50kHz for 2-3 minutes, with the water pressure maintained at 0.1-0.2MPa.

[0050] The circuit board is sent into a pure water spray cleaning equipment and sprayed bidirectionally at a pressure of 0.3-0.5MPa for 3-5 minutes to ensure that the residual demasking liquid and impurities on the board surface are completely removed.

[0051] Place the cleaned ceramic circuit board into a hot air circulating drying oven, set the oven temperature to 80-90℃, the hot air circulation speed to 2.0-3.0m / s, and the drying time to 10-15 minutes.

[0052] During the drying process, the surface humidity of the circuit board is monitored in real time. Drying is stopped when the surface humidity drops to ≤0.5% and the temperature difference between the circuit board surface and the temperature inside the drying chamber does not exceed 3℃.

[0053] Furthermore, the high-precision etching equipment for ceramic circuit boards based on inkjet masks, applied to the aforementioned high-precision etching method for ceramic circuit boards based on inkjet masks, includes: a support platform, a positioning component, an inkjet mask module, and a curing device.

[0054] The support platform is made of ceramic matrix composite material, and a three-axis moving component is provided at the bottom of the support platform;

[0055] The positioning component includes a multi-point adsorption mechanism and a laser alignment system. The multi-point adsorption mechanism is located on the top of the support platform and fixes the ceramic circuit board by vacuum negative pressure to prevent displacement during inkjet printing or etching. The laser alignment system is located on one side of the multi-point adsorption mechanism and is used to perform high-precision identification of key graphic marks on the ceramic circuit board to achieve precise alignment between the inkjet graphic and the substrate.

[0056] The inkjet mask module includes a printhead assembly, an ink storage mechanism, and a pressurized supply system. The printhead assembly is surrounded by a constant temperature ink supply conduit. The printhead assembly is mounted on the inkjet mask module. An infrared detection probe is located on the side of the printhead assembly closest to the support platform. The infrared detection probe is used to monitor the print quality in real time during the printing process and to perform online reprinting for broken lines and exposed copper defects based on the quality monitoring results. The printhead assembly is connected to the ink storage mechanism through the pressurized supply system.

[0057] Furthermore, the curing device is located downstream of the inkjet mask module. The curing device includes an ultraviolet curing unit and a thermosetting auxiliary module. The ultraviolet curing unit uses a multi-band high-energy UV light source, and the thermosetting auxiliary module is a constant-temperature heating chamber.

[0058] Compared with the prior art, the beneficial effects of the present invention are:

[0059] 1. This invention uses a multi-point adsorption mechanism to fix the circuit board under vacuum negative pressure, and a laser alignment system to perform high-precision scanning and recognition of the reference marks. This drives the three-axis fine-tuning of the alignment accuracy of the carrier platform, ensuring that the inkjet pattern is accurately aligned with the substrate and avoiding pattern misalignment caused by positioning deviation. In the inkjet printing process, a preset parameter group is called according to the characteristics of the graphic file, and staggered scanning is used to monitor the printing quality in real time. Online reprinting is performed for broken lines and exposed copper defects, ensuring high precision and high quality of mask pattern printing. The graphic edges are clear and the lines are uniform, effectively improving the masking effect and etching resistance of the mask.

[0060] 2. The high-precision etching equipment for ceramic circuit boards based on inkjet masks in this invention features coordinated operation of all components, providing a reliable guarantee for the implementation of the etching method. The support platform can accurately coordinate with the operation of the positioning component and the inkjet mask module. The vacuum negative pressure fixation of the multi-point adsorption mechanism and the high-precision identification of the laser alignment system in the positioning component enable rapid and accurate positioning of the circuit board. The printhead assembly, ink storage and pressurized supply system of the inkjet mask module, together with the ink supply constant temperature conduit and infrared detection probe, realize micron-level resolution printing, stable ink supply and real-time quality monitoring and reprinting, ensuring high-precision printing of the mask pattern, and significantly improving the automation, processing accuracy and production efficiency of ceramic circuit board etching. Attached Figure Description

[0061] Figure 1 This is a schematic diagram of the high-precision etching method for ceramic circuit boards according to the present invention;

[0062] Figure 2 This is a schematic diagram of the support platform structure of the present invention;

[0063] Figure 3 This is a schematic diagram of the curing device of the present invention.

[0064] In the diagram: 1. Support platform; 11. Three-axis moving assembly; 2. Positioning assembly; 21. Multi-point adsorption mechanism; 22. Laser alignment system; 3. Inkjet mask module; 31. Printhead assembly; 32. Ink storage mechanism; 33. Pressurized supply system; 34. Ink supply constant temperature conduit; 35. Infrared detection probe; 41. Ultraviolet curing unit; 42. Thermosetting auxiliary module. Detailed Implementation

[0065] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0066] Please see Figure 1 The present invention provides the following technical solutions:

[0067] Example 1: A high-precision etching method for ceramic circuit boards based on inkjet masks, comprising:

[0068] Step 1: Wash the ceramic circuit board to be processed by spraying with a combination of high-purity water and inorganic cleaning agent and then dry it, strictly controlling the concentration, time and temperature parameters of the cleaning solution;

[0069] Step 2: Place the cleaned ceramic circuit board on the support platform and align the graphic reference using laser alignment. Start the inkjet mask module and print the graphic inkjet mask on the surface of the ceramic circuit board according to the input graphic file. During the printing process, control the nozzle ejection frequency, printing speed, line width and dot density.

[0070] Step 3: After printing, the ink is initially cured using a UV curing unit, which uses a high-energy UV light source to promote the rapid formation of a hard film on the ink surface.

[0071] Step 4: Transfer the ceramic circuit board that has been cured by the mask to the etching tank assembly. Select the etching solution according to the etching requirements and set the etching time, liquid temperature and ultrasonic vibration intensity. During the etching process, selectively etch the areas not covered by the mask.

[0072] Step 5: After etching is completed, the ceramic circuit board is sent to the cleaning and drying module. The mask pattern is dissolved by the mask remover, and the removal process is accelerated by ultrasonic assistance. After the removal process is completed, the board surface is cleaned by spraying pure water and dried by hot air circulation.

[0073] Step one also includes:

[0074] Deionized water is used as the high-purity water raw material. The inorganic cleaning agent is a 5%-10% sodium hydroxide and sodium carbonate mixed solution with a mass ratio of sodium hydroxide to sodium carbonate of 3:2. The cleaning solution is prepared by mixing high-purity water and inorganic cleaning agent in a volume ratio of 9:1. The temperature of the mixed solution is controlled at 40-50℃, the stirring speed is 200-300 rpm, and the stirring is continued for 15-20 minutes to ensure that the cleaning solution is mixed evenly.

[0075] The prepared cleaning solution is sprayed bidirectionally onto the ceramic circuit board at a pressure of 0.3-0.5 MPa for 8-12 minutes, while maintaining the cleaning solution temperature at 45±2℃. After the cleaning is completed, the ceramic circuit board is transferred to a hot air drying oven with a hot air temperature of 80-90℃, a wind speed of 1.5-2.0 m / s, and a drying time of 15-20 minutes to ensure that the residual moisture on the surface of the ceramic circuit board is completely evaporated and that the temperature difference between the surface of the circuit board and the ambient temperature does not exceed 5℃.

[0076] In the above embodiments, the combined spraying and washing of ceramic circuit boards using high-purity water and a specifically proportioned inorganic cleaning agent offers significant technical advantages. Deionized water is selected as the high-purity water raw material, and the inorganic cleaning agent, composed of a 5%-10% sodium hydroxide and sodium carbonate mixed solution (mass ratio 3:2), is prepared at a 9:1 volume ratio. Precise control of the cleaning solution concentration effectively removes oil, dust, oxides, and other impurities from the surface of the ceramic circuit board. By strictly setting the cleaning solution temperature at 40-50℃, the stirring speed at 200-300 rpm, and continuous stirring for 15-20 minutes, uniform mixing of the cleaning solution is ensured, enhancing the cleaning effect. Bidirectional cross-spraying under 0.3-0.5MPa pressure, a spraying time of 8-12 minutes, and constant temperature control at 45±2℃ ensure a highly efficient and stable cleaning process. The subsequent hot air drying oven settings of 80-90℃, 1.5-2.0m / s airflow, and 15-20 minutes ensure complete evaporation of moisture from the circuit board surface, preventing residual water stains or cleaning agents from affecting subsequent processing. This refined cleaning and drying process effectively improves the cleanliness and smoothness of the ceramic circuit board surface, providing a solid foundation for subsequent inkjet masking, etching, and other processes. It guarantees processing accuracy and product quality, reduces defects caused by surface impurities, and improves production efficiency and yield.

[0077] Step two also includes:

[0078] The ceramic circuit board is placed in the positioning area of ​​the support platform, and the multi-point adsorption mechanism is activated to fix the ceramic circuit board under a vacuum negative pressure of -0.08 to -0.1MPa. Then, the laser alignment system is triggered, and a green laser with a wavelength of 532nm is used to scan and identify the cross-shaped or circular reference marks with a diameter of 0.1-0.3μm on the ceramic circuit board. The position deviation is calculated by the image recognition algorithm, and the support platform is driven to perform three-axis fine adjustment.

[0079] Based on the characteristics of the input graphic file, the preset inkjet process parameter group is called, and the printhead ejection frequency is set to 20-50kHz, the printing speed to 50-100μm / s, the line width control accuracy to ±3μm, and the dot matrix density to 300-1200DPI.

[0080] UV-curable mask ink is delivered to the printhead assembly, with the ink supply pressure maintained at 0.2-0.4 MPa and the temperature controlled at 30±2℃. Graphics are printed using an interlaced scanning method, and the print quality is monitored in real time during the printing process. Defects such as broken lines and exposed copper are repaired online.

[0081] In the above embodiments, the circuit board is fixed under a vacuum pressure of -0.08 to -0.1 MPa using a multi-point adsorption mechanism. A 532nm green laser, in conjunction with a laser alignment system, performs high-precision scanning and recognition of 0.1-0.3μm reference marks. This drives the three-axis fine-tuning of the support platform to achieve alignment accuracy within ±5μm, ensuring precise alignment between the inkjet pattern and the substrate and avoiding misalignment caused by positioning deviations. During inkjet printing, a preset parameter set is invoked based on the graphic file characteristics, controlling the printhead ejection frequency at 20-50kHz, printing speed at 50-100μm / s, linewidth accuracy at ±3μm, and dot density at 300-1200 DPI. Simultaneously, an ink supply pressure of 0.2-0.4 MPa and an ink supply temperature of 30±2℃ are used. Interlaced scanning and real-time monitoring of printing quality are employed, with online reprinting for broken lines and exposed copper defects. This ensures high precision and high quality in mask pattern printing, resulting in clear edges and uniform lines, effectively improving the mask's shielding effect and etching resistance.

[0082] Specifically, the system monitors print quality in real time during the printing process and issues alarms when print quality is abnormal, including:

[0083] The number of broken lines and the length of missing lines corresponding to the location of the broken lines are monitored in real time during the printing process.

[0084] The total value of the missing length of the broken line is obtained according to the missing length of the broken line corresponding to the broken line location during each printing process.

[0085] The ratio of the total length of the broken lines to the total length of the printing thread is calculated to obtain the length ratio coefficient between the total length of the broken lines and the total length of the printing thread.

[0086] Filter the locations of broken wires;

[0087] The missing length of the broken line at each broken line location is compared with the preset broken line length threshold.

[0088] Filter out the locations of broken lines whose missing length exceeds a preset broken line length threshold, and use them as target broken line locations;

[0089] Based on the target break location, obtain the straight-line distance between the center points of the break between any two target break locations;

[0090] The length ratio coefficient between the total length of the missing lines and the total length of the printing thread is used in conjunction with the straight-line distance between the center points of the missing lines at every two target missing line locations to determine whether the printing quality of the current printing process meets the quality requirements, and an abnormal alarm is issued when the printing quality of the current printing process does not meet the quality requirements.

[0091] The technical effects of the above solution are as follows: By calculating the sum of all broken line lengths, the total amount of material lost due to broken lines during a single printing process can be quantified. For example, if the total broken line length in a certain printing is 5μm, and the total printing length is 100μm, the missing percentage is 5%, which can intuitively reflect the severity of the defect. It avoids relying solely on local judgments based on a single broken line location, achieving global defect quantification. The ratio of the total broken line length to the total printing thread length (e.g., a 5% missing percentage) is used as a standardized indicator to eliminate the influence of length differences between different printing tasks. For example, whether printing a 10cm or 1m line, the degree of defect can be compared horizontally using the ratio coefficient. A unified quality assessment standard is established, supporting quality comparisons between different printing tasks. By setting a broken line length threshold (e.g., 1μm), broken line locations exceeding the threshold are selected as target broken line locations. For example, if a broken line length of 2μm (exceeding the threshold) is marked as a target broken line location, while broken lines of 0.5μm are ignored. It focuses on defects that have a significant impact on printing quality, reducing irrelevant noise interference. Calculating the straight-line distance between the center points of adjacent broken lines can identify defect distribution patterns. For example, if multiple broken line locations are concentrated in a certain area (e.g., center point distance < 5 μm), it may indicate that the printhead is clogged or worn in that area. Combined with spatial distribution information, this helps locate the source of equipment failure (e.g., printhead, transmission system). Printing quality is only considered unacceptable when the total percentage of missing line lengths is high (e.g., ratio > 3%) and the broken line locations are densely distributed (e.g., adjacent center point distance < 10 μm). For example, if the ratio of missing line lengths in a print run is 4% but the broken line locations are scattered, it may be due to accidental factors and no alarm is needed; however, if the ratio is 2% but the broken line locations are concentrated, it may still trigger an alarm due to severe local defects. The broken line length threshold can be dynamically adjusted according to the printing material and precision requirements (e.g., the threshold is set to 0.5 μm for high-precision printing and 2 μm for low-precision printing), achieving flexible adaptation to different scenarios. This balances efficiency and quality, adapting to diverse production needs. By calculating the total length of missing wires, the ratio coefficient, and the distribution of target broken wire locations in real time, alarms can be triggered instantly upon the occurrence of defects (such as audible and visual alerts and system log recordings), preventing the accumulation of defects that could lead to mass scrapping. This shortens fault response time and reduces production costs. Recording the target broken wire locations and their spatial distribution characteristics provides data support for equipment maintenance. For example, if the broken wire locations are consistently concentrated at one end of the printhead's movement path, it may indicate that the drive guide rails need cleaning or lubrication. This shifts the focus from passive response to proactive prevention, improving equipment stability.

[0092] During inkjet mask etching, uneven ink droplet deposition or mask defects can lead to issues such as circuit linewidth deviations and broken lines. This technical solution, by monitoring the number, location, and length of broken lines in real time, can accurately locate etching defects (such as insufficient local linewidth or broken lines), ensuring that the circuit pattern meets design requirements. If a circuit linewidth is designed to be 50μm, but a 20μm gap is caused by a broken line, the solution can immediately identify and mark the defect location. By calculating the total length of broken lines and the length ratio coefficient, the defect severity can be quantified into a specific value (e.g., a 5% missing percentage), providing an objective basis for subsequent process adjustments. This avoids subjective errors from manual visual inspection, improving the accuracy and consistency of defect detection. During ceramic circuit board etching, if the total length of broken lines or the ratio coefficient exceeds a preset threshold (e.g., a missing percentage > 3%), the solution can immediately trigger an alarm, notifying operators or automatically adjusting process parameters (e.g., inkjet pressure, mask position). This shortens fault response time, reduces batch scrap due to defect accumulation, and improves yield to over 95% (assuming an original yield of 90%). By combining alarm information, the deposition parameters of the inkjet mask (such as droplet size and deposition rate) can be dynamically adjusted to achieve closed-loop control of the etching process. If a dense cluster of broken lines is detected in a certain area, the inkjet volume in that area can be automatically increased or the mask alignment accuracy adjusted. By calculating the straight-line distance from the center point of the broken line at the target location, the distribution pattern of defects (such as local clustering or random distribution) can be analyzed, assisting in locating the source of equipment failure (such as printhead clogging or mask wear). This upgrades from "defect detection" to "defect tracing," providing data support for process improvement. Accumulating defect data (such as broken line location and missing length) from multiple batches of etching processes allows for the establishment of quality prediction models to identify potential risks in advance. If the broken line rate of a printhead increases significantly after producing 100 circuit boards continuously, its lifespan can be predicted and it can be replaced in advance. Through real-time early warning and closed-loop control, the scrap rate caused by etching defects can be reduced by 30%-50% (assuming the original scrap rate is 10%), significantly saving raw material costs. Reducing production interruptions caused by downtime due to malfunctions can improve the overall equipment efficiency (OEE) by 15%-20%. This technology shortens production cycles and meets the needs of small-batch, multi-variety production of high-precision ceramic circuit boards. The etching linewidth of ceramic circuit boards is typically 10-50μm. The proposed solution, through high-precision line break detection (e.g., a missing length resolution of 1μm), can meet micron-level process requirements. Traditional visual inspection struggles to detect defects <10μm, while this solution enables full-coverage detection. It is applicable to ceramic substrates such as alumina and aluminum nitride, as well as conductive inks such as silver paste and copper paste, and can adapt to different material properties by adjusting the line break length threshold.

[0093] Specifically, the print quality of the current printing process is determined by combining the ratio coefficient between the total length of missing lines and the total length of the printing thread with the straight-line distance between the center points of the missing lines at every two target missing line locations. This includes:

[0094] The printing area is divided into grids according to the preset grid size to obtain multiple grid areas corresponding to the printing area;

[0095] Extract the number of broken lines corresponding to each grid region;

[0096] The standard deviation of the number of broken lines in multiple grid regions corresponding to the printing area is obtained based on the number of broken lines appearing in each grid region.

[0097] The standard deviation of the number of broken wires is normalized to obtain the normalized standard deviation of the number of broken wires.

[0098] Extract the length ratio coefficient between the total length of broken or missing lines and the total length of the printing thread;

[0099] Extract the straight-line distance between the center points of the broken lines at every two target broken line locations;

[0100] The straight-line distance between the center points of the broken lines at every two target broken line locations is normalized using a preset straight-line distance reference value to obtain the normalized straight-line distance; wherein the preset straight-line distance reference value has a range of 1.27D. max -1.53D max And, D max This represents the maximum straight-line distance between the center points of any two target break points;

[0101] The print quality coefficient is obtained using the normalized standard deviation of the number of broken lines, the length ratio coefficient, and the normalized straight-line distance.

[0102] The print quality coefficient is obtained using the following formula:

[0103]

[0104] Where J represents the print quality coefficient; B represents the standard deviation of the number of broken lines after normalization; L represents the length ratio coefficient; n represents the number of target broken line locations; D i This represents the normalized straight-line distance between every two target breakpoints in the i-th pair; specifically, The standard deviation (B) measures the dispersion of data. In a printing scenario, the standard deviation of broken line count reflects the fluctuation of broken line count across different printing areas or during the printing process. A larger B value indicates more drastic fluctuations in the number of broken lines, resulting in less stable print quality. With 1+B in the denominator, it means that the larger the B value, the smaller the value of (1+B)*L, i.e., the lower the print quality coefficient, reflecting the negative impact of broken line count fluctuations on print quality. The length ratio coefficient L is the ratio of the total broken line length to the total length of the printing thread. A larger L indicates a larger proportion of total broken line length during printing, resulting in poorer print quality. In the denominator, it also reflects the logical relationship that a larger L value corresponds to a smaller print quality coefficient J, reflecting the adverse impact of broken line length on print quality. D i This is the normalized straight-line distance between every two target break points. The target break point refers to the location where the missing length of the break point exceeds a preset threshold. (D) i This reflects the intervals between these critical break points. If D i A smaller value indicates that the broken lines are concentrated in a relatively concentrated area, reflecting a serious problem with the printhead within a certain period or region; if D... i A large value indicates that the target break points are relatively dispersed. The multiplication operation is a method that comprehensively considers the distance relationships between all target break points, multiplying each D... i Multiplying the ratio to L reflects the comprehensive relationship between the target breakage location spacing and the overall breakage situation. Taking the nth root is equivalent to averaging the product, yielding a value that comprehensively reflects the characteristics of the target breakage location spacing. This part is multiplied by the preceding part in the formula to further comprehensively consider the impact of breakage location spacing on print quality. This formula considers the stability of the number of breakages (through standard deviation B), the proportion of total breakage length (through L), and the spacing of key breakage locations (through D). iThe print quality coefficient is calculated by comprehensively considering multiple dimensions, including the number of broken lines and the proportion of broken lines. Print quality is affected by various factors, and this multi-dimensional approach aligns with the physical logic of quality impacts during actual printing, providing a more comprehensive and reasonable reflection of print quality. The correlation between the parameters in the formula and print quality is logical; for example, large fluctuations in the number of broken lines, a high proportion of broken line length, and a concentration of critical broken line locations all lead to poor print quality. The formula, through the position and operational relationships of the parameters in the calculation, reasonably reflects the negative impact of these factors on print quality. Through specific numerical calculations, different influencing factors are quantified and synthesized into a single print quality coefficient J. Compared to relying solely on human experience or a single indicator to judge print quality, this quantification method is more precise and objective, more accurately reflecting the actual quality level. Because it considers multiple factors, the formula can distinguish between different types of print quality problems. For example, when the standard deviation of the number of broken lines (B) is large and the length ratio coefficient (L) is relatively small, it indicates that the print quality problem mainly lies in the fluctuation of the number of broken lines; when L is large, it indicates that the main problem is a high proportion of broken line length. This helps to pinpoint the root cause of print quality problems more accurately, and thus take more targeted improvement measures.

[0105] The print quality coefficient is compared with a preset print quality coefficient threshold.

[0106] When the print quality coefficient is lower than the preset print quality coefficient threshold, it is determined that the print quality of the current printing process does not meet the quality requirements.

[0107] The technical effects of the above solution are as follows: By dividing the printing area into pre-defined grid sizes and quantifying the number of broken lines within each grid, a refined analysis of the spatial distribution of defects can be achieved. For example, in ceramic circuit board etching, if the number of broken lines in a certain grid is significantly higher than in other areas, the source of the problem (such as nozzle clogging or mask alignment deviation) can be quickly located. The standard deviation of the number of broken lines and its normalization result can reflect the spatial uniformity of defect distribution, providing data support for process optimization. The straight-line distance between the center points of broken lines is normalized using a pre-defined straight-line distance reference value (1.27Dmax-1.53Dmax), eliminating the influence of different circuit board sizes on distance judgment. For example, for a circuit board with a line width of 50μm, the normalized straight-line distance can be directly used for cross-batch quality comparison. The normalized straight-line distance can reveal the clustering or dispersion trend of broken line locations, assisting in the judgment of fault types (such as local clogging or global inkjet unevenness). The normalized standard deviation of the number of broken lines, the length ratio coefficient, and the normalized straight-line distance are combined into a print quality coefficient, avoiding the limitations of a single indicator. For example, if the standard deviation of the number of broken wires on a circuit board is low but the length ratio coefficient is high, it may indicate that the defects are concentrated in the critical circuits, and it should still be judged as a quality failure. The preset printing quality coefficient threshold can be dynamically adjusted according to the precision requirements of the ceramic circuit board (e.g., the threshold is set to 0.8 for high-precision circuit boards and 0.9 for low-precision circuit boards), achieving flexible adaptation. The uniformity of defects is analyzed by the standard deviation of the number of broken wires (e.g., a high standard deviation indicates uneven defect distribution), and the severity of defects is judged by combining the length ratio coefficient and straight-line distance. Once the printing quality coefficient is lower than the threshold, an alarm is immediately triggered and process parameters (e.g., inkjet pressure, mask movement speed) are automatically adjusted to reduce the scrap rate. Through real-time monitoring and closed-loop control, the scrap rate caused by etching defects can be reduced by 20%-40% (assuming the original scrap rate is 15%), significantly saving raw material costs. It reduces manual visual inspection time, and the overall equipment efficiency (OEE) is improved by 10%-15%, meeting the needs of small-batch, multi-variety production of high-precision ceramic circuit boards. By statistically analyzing the number of broken lines using a gridded approach and normalizing the straight-line distance, the distribution patterns of defects (such as local clustering or random distribution) are identified, aiding in locating equipment failure sources (such as nozzle wear or mask alignment deviation). This upgrades the process from "defect detection" to "defect tracing," providing data support for process improvement. Accumulating defect data from multiple etching batches (such as the number of broken lines, length ratio coefficient, and normalized straight-line distance indicators) ensures objectivity and impartiality, avoiding errors caused by subjective judgment and enhancing quality reliability. Ceramic circuit board etching linewidths are typically 10-50μm. The technical solution, through gridded analysis and normalization, can accurately adapt to the etching requirements of micron-level linewidth ceramic circuit boards, ensuring that detection accuracy matches etching accuracy. For highly conductive ceramic circuit boards, priority will be given to ensuring the adaptability of detection parameters (such as the number of broken lines, length ratio coefficient, and broken line distribution density, which will be key monitoring targets to ensure a strong correlation with the etching process).By leveraging user feedback on print quality coefficients, the normalization threshold or grid size can be dynamically adjusted to improve the adaptability of the solution.

[0108] Step three also includes:

[0109] The inkjet-printed ceramic circuit board is fed into the UV curing unit via a carrier platform. A multi-band high-energy UV light source is turned on, and the ceramic circuit board passes through the light source at a transmission speed of 2-5 m / min. The curing time for each pass is controlled at 3-8 seconds, so that a hard film with a hardness of ≥2H is quickly formed on the surface of the mask ink, which inhibits ink diffusion.

[0110] After initial curing, the ceramic circuit board is transferred to the thermosetting auxiliary module. The module temperature is set to 120-150℃, the heating rate is controlled at 5-10℃ / min, and the temperature is maintained for 15-30 minutes to improve the adhesion and etching resistance between the mask pattern and the surface of the ceramic circuit board.

[0111] Microscopic inspection is performed on the cured mask pattern to check the edge clarity, surface flatness, and presence of bubbles or cracks. Areas with edge deviation >2μm, roughness Ra >0.5μm, or presence of bubbles or cracks are automatically marked as unqualified areas and returned to the UV curing unit for secondary curing.

[0112] In the above embodiments, the mask curing process, through a combination of initial UV curing and thermosetting-assisted deep curing, along with a rigorous quality inspection mechanism, significantly improves the performance of the mask pattern. The UV curing unit, with a transmission speed of 2-5 m / min and a single curing time of 3-8 seconds, combined with a multi-band high-energy UV light source, rapidly forms a hard film with a hardness ≥2H on the surface of the mask ink, effectively inhibiting ink diffusion and quickly fixing the pattern outline. The thermosetting-assisted module sets the temperature to 120-150℃ and maintains it at a heating rate of 5-10℃ / min for 15-30 minutes, promoting full cross-linking within the ink and significantly improving the adhesion (peel strength ≥3N / μm) and etching resistance between the mask pattern and the ceramic circuit board surface. Microscopic inspection of pattern edge clarity (edge ​​deviation ≤2μm), surface flatness (roughness Ra≤0.5μm) and defects is performed using an optical microscope at magnification of 100-500x. Defective areas are then cured a second time to ensure that the mask pattern of each circuit board meets high standards, thereby improving the stability and reliability of the mask pattern and reducing etching defects caused by mask quality issues.

[0113] Step four also includes:

[0114] The etching solution is injected into the corrosion-resistant tank, and the temperature of the etching solution is adjusted to 45-65℃ by the constant temperature control unit. The vibration frequency of the ultrasonic exciter is set to 20-40kHz, and the power density is 0.5-1.5W / cm².

[0115] The ceramic circuit board with the mask cured is vertically immersed in the etching solution, and the etching solution is circulated at a flow rate of 0.5-1.5m / s. At the same time, the ultrasonic vibration source is turned on. For patterns with a line width ≥50μm, the etching time is controlled at 5-10 minutes; for fine patterns with a line width <50μm, the etching time is controlled at 3-8 minutes.

[0116] During the etching process, the concentration of the etching solution is monitored. When the concentration of the main component of the etching solution fluctuates by more than ±5%, the concentrate is automatically added for adjustment.

[0117] The etching depth of the non-mask-covered area is monitored in real time using a laser reflective thickness gauge. When the preset etching depth is reached, the ceramic circuit board is removed from the etching tank and quickly transferred to the cleaning tank for spray cleaning. The cleaning water pressure is 0.2-0.4MPa and the cleaning time is 2-5 minutes to terminate the etching reaction and remove the residual etching solution on the surface.

[0118] In the above embodiments, the etching process in step four achieves efficient and precise etching results through precise selection of etching solution, parameter setting, and real-time monitoring and control. A suitable etching solution is selected based on the ceramic circuit board material; for example, a mixed solution of hydrofluoric acid and nitric acid is used for alumina ceramics, and sodium hydroxide solution is used for aluminum nitride ceramics. The etching solution concentration and temperature are strictly controlled between 45-65℃, the ultrasonic exciter vibration frequency is 20-40kHz, and the power density is 0.5-1.5W / cm², coupled with an etching solution circulation rate of 0.5-1.5m / s. Appropriate etching times are set for different linewidth patterns to ensure a uniform and efficient etching process. The etching solution concentration is monitored in real time, and when the concentration fluctuation of the main component exceeds ±5%, concentrated solution is automatically added to maintain a stable etching reaction. A laser reflective thickness gauge is used to monitor the etching depth in real time, with deviations controlled within ±2μm. Once the preset depth is reached, the circuit board is promptly removed and cleaned to avoid over-etching or under-etching. This refined etching process control can precisely etch areas not covered by the mask, ensuring the dimensional accuracy and surface quality of the etched pattern, and improving the consistency and yield of ceramic circuit board etching.

[0119] Step five also includes:

[0120] The etched ceramic circuit board is immersed in a demasking solution tank. The demasking solution is a potassium carbonate aqueous solution with a mass concentration of 15%-25% and the temperature is controlled at 50-60℃. At the same time, the ultrasonic auxiliary device is turned on, the ultrasonic frequency is set to 40-60kHz, and the power density is 0.3-0.8W / cm².

[0121] The immersion time of the ceramic circuit board is adjusted according to the mask thickness. When the mask thickness is ≤10μm, the immersion time is controlled at 3-5 minutes; when the mask thickness is >10μm, the immersion time is controlled at 5-8 minutes, until the mask pattern is completely dissolved and detached from the ceramic circuit board surface.

[0122] The ceramic circuit board after mask removal was ultrasonically cleaned with deionized water at a frequency of 30-50kHz for 2-3 minutes, with the water pressure maintained at 0.1-0.2MPa.

[0123] The circuit board is sent into a pure water spray cleaning equipment and sprayed bidirectionally at a pressure of 0.3-0.5MPa for 3-5 minutes to ensure that the residual demasking liquid and impurities on the board surface are completely removed.

[0124] Place the cleaned ceramic circuit board into a hot air circulating drying oven, set the oven temperature to 80-90℃, the hot air circulation speed to 2.0-3.0m / s, and the drying time to 10-15 minutes.

[0125] During the drying process, the surface humidity of the circuit board is monitored in real time. Drying is stopped when the surface humidity drops to ≤0.5% and the temperature difference between the circuit board surface and the temperature inside the drying chamber does not exceed 3℃.

[0126] In the above embodiments, the cleaning and drying operation in step five effectively removes the etched mask and impurities, ensuring the final quality of the ceramic circuit board. Using a 15%-25% potassium carbonate aqueous solution as the mask remover, and employing an ultrasonic frequency of 40-60kHz and a power density of 0.3-0.8W / cm² at a temperature of 50-60℃, with the soaking time adjusted according to the mask thickness, the mask pattern can be quickly and thoroughly dissolved, preventing mask residue from affecting the circuit board performance. The subsequent multi-stage cleaning process involves first ultrasonic cleaning with deionized water at a 30-50kHz ultrasonic frequency and a water pressure of 0.1-0.2MPa, followed by bidirectional cross-spraying with pure water at a pressure of 0.3-0.5MPa to ensure complete removal of any remaining mask remover and impurities from the board surface. Finally, the circuit board is dried in a hot air circulating drying oven at a temperature of 80-90℃ and a wind speed of 2.0-3.0m / s. The humidity is monitored in real time and the drying is stopped when it drops to ≤0.5% and the temperature difference does not exceed 3℃. This ensures that the surface of the circuit board is dry and clean, so that the ceramic circuit board achieves extremely high cleanliness and dryness after etching. This provides good conditions for the subsequent assembly and use of the circuit board and reduces the risk of circuit failure caused by residual substances.

[0127] Please see Figures 2-3 The high-precision etching equipment for ceramic circuit boards based on inkjet masks, applied in the above-mentioned high-precision etching method for ceramic circuit boards based on inkjet masks, includes: a support platform 1, a positioning component 2, an inkjet mask module 3, and a curing device.

[0128] The support platform 1 is made of ceramic matrix composite material, and a three-axis moving component 11 is provided at the bottom of the support platform;

[0129] The positioning component 2 includes a multi-point adsorption mechanism 21 and a laser alignment system 22. The multi-point adsorption mechanism 21 is located on the top of the support platform 1. The multi-point adsorption mechanism 21 fixes the ceramic circuit board by vacuum negative pressure to prevent displacement during inkjet printing or etching. The laser alignment system 22 is located on one side of the multi-point adsorption mechanism 21. The laser alignment system 22 is used to perform high-precision identification of key graphic marks on the ceramic circuit board to achieve precise alignment between the inkjet graphic and the substrate.

[0130] The inkjet mask module 3 includes a printhead assembly 31, an ink storage mechanism 32, and a pressurized supply system 33. The printhead assembly 31 is surrounded by an ink supply thermostatic conduit 34. The printhead assembly 31 is mounted on the inkjet mask module 3. An infrared detection probe 35 is provided on the side of the printhead assembly 31 near the support platform 1. The infrared detection probe 35 is used to monitor the printing quality in real time during the printing process and to perform online reprinting for broken lines and exposed copper defects based on the quality monitoring results. The printhead assembly 31 is connected to the ink storage mechanism 32 through the pressurized supply system 33.

[0131] The curing device is located downstream of the inkjet mask module. The curing device includes an ultraviolet curing unit 41 and a thermosetting auxiliary module 42. The ultraviolet curing unit 41 adopts a multi-band high-energy UV light source, and the thermosetting auxiliary module 42 is a constant temperature heating chamber.

[0132] In the above embodiments, the components of the high-precision etching equipment for ceramic circuit boards based on inkjet masks work collaboratively, providing a reliable guarantee for the implementation of the etching method. The support platform is made of ceramic matrix composite material and equipped with a three-axis moving component, which has high stability, high flatness, and excellent corrosion resistance, ensuring the dimensional stability and positioning accuracy of the circuit board during processing, and can accurately cooperate with the operation of the positioning component and the inkjet mask module. The vacuum negative pressure fixation of the multi-point adsorption mechanism and the high-precision identification of the laser alignment system in the positioning component realize the rapid and accurate positioning of the circuit board, providing reliable support for the alignment of the inkjet pattern with the substrate. The printhead assembly, ink storage and pressurization supply system of the inkjet mask module, together with the ink supply constant temperature conduit and infrared detection probe, realize micron-level resolution printing, stable ink supply, and real-time quality monitoring and reprinting, ensuring high-precision printing of the mask pattern. The ultraviolet curing unit and thermosetting auxiliary module of the curing device realize rapid preliminary curing of the mask pattern and deep performance improvement, respectively. These equipment components work together to effectively implement the various process parameters and operating procedures in the etching method. Compared with traditional etching equipment, this equipment significantly improves the automation level, processing accuracy and production efficiency of ceramic circuit board etching.

[0133] Based on the solution in Example 1, the above technical solution will be illustrated through the following two examples:

[0134] Example 2: Etching of alumina ceramic circuit boards with line width ≥ 50 μm

[0135] Application scenarios: Suitable for high-power electronic device substrates, such as inverter modules for new energy vehicles, which need to withstand high current loads and have high requirements for etching uniformity and line accuracy (line width tolerance ±5μm).

[0136] Step 1: Cleaning and Drying

[0137] The cleaning solution is mixed with high-purity water at a volume ratio of 9:1. The inorganic cleaning agent is a 5% concentration mixed solution of NaOH and Na2CO3 (mass ratio 3:2). The mixing temperature is 45℃, the stirring speed is 250 rpm, and the stirring is continued for 18 minutes. The spray cleaning pressure is 0.4MPa, and the spraying is carried out in both directions for 10 minutes at a constant temperature of 45±2℃. The drying hot air temperature is 85℃, the wind speed is 1.8m / s, and the drying is carried out for 18 minutes. The surface temperature difference is ≤5℃.

[0138] Step 2: Inkjet mask printing

[0139] The ceramic circuit board is positioned and fixed under vacuum negative pressure of -0.09MPa. A laser alignment system (532nm green laser) identifies a φ0.2μm circular reference mark with an alignment accuracy of ±3μm. The printhead ejection frequency is 30kHz, the printing speed is 80μm / s, the line width control accuracy is ±3μm, and the dot matrix density is 600DPI. The ink supply pressure is 0.3MPa, the temperature is 30±2℃, and staggered scanning is used to monitor and repair broken lines in real time (threshold: missing length >1μm).

[0140] Step 3: Mask curing

[0141] UV curing transfer speed 3m / min, single curing time 5 seconds, UV light source intensity 800mJ / cm², hard film hardness 2H; thermosetting auxiliary temperature 130℃, heating rate 8℃ / min, constant temperature for 20 minutes, adhesion 3N / μm.

[0142] Step 4: Etching

[0143] Temperature control at 55℃, ultrasonic frequency at 30kHz, power density at 1.0W / cm², etching solution flow rate at 1.0m / s; etching time at 8 minutes, real-time concentration monitoring (automatic replenishment if fluctuation > ±5%), laser thickness measurement to control depth at ±2μm;

[0144] Step 5: Remove mask and clean / dry

[0145] Mask removal solution: 20% potassium carbonate aqueous solution, temperature 55℃, ultrasonic frequency 50kHz, power density 0.5W / cm², immersion time 4 minutes (mask thickness 8μm); ultrasonic cleaning with deionized water (40kHz, 0.15MPa) for 2 minutes, followed by pure water spraying (0.4MPa) for 4 minutes; hot air drying at 85℃, wind speed 2.5m / s, humidity ≤0.5% and temperature difference ≤3℃ (approximately 12 minutes).

[0146] Equipment configuration: Ceramic matrix composite material support platform with three-axis movement accuracy of ±2μm; inkjet module printhead resolution of 1200DPI, infrared detection probe for real-time monitoring of line breakage (accuracy of 1μm); curing device with multi-band UV light source (365nm / 405nm), thermosetting module with temperature control accuracy of ±1℃.

[0147] Example 3: Fine etching of aluminum nitride ceramic circuit boards with line width < 50 μm

[0148] Application scenarios: Suitable for high-frequency communication device substrates, such as 5G RF modules, requiring linewidth tolerance of ±2μm and etched surface roughness Ra≤0.3μm.

[0149] Step 1: Cleaning and Drying

[0150] Prepare a cleaning solution by mixing 10% NaOH and Na2CO3 in a 9:1 mass ratio (3:2). Maintain a temperature of 50℃ and a stirring speed of 300 rpm for 20 minutes. Perform a spray cleaning at a pressure of 0.5 MPa, with bidirectional cross-spraying for 8 minutes at a constant temperature of 45±2℃. Dry with hot air at 90℃ and a wind speed of 2.0 m / s for 15 minutes, maintaining a surface temperature difference of ≤4℃.

[0151] Step 2: Inkjet mask printing

[0152] The ceramic circuit board is positioned and fixed under vacuum negative pressure of -0.1MPa. The laser alignment system identifies 0.1μm cross-shaped reference marks with an alignment accuracy of ±2μm. The printhead ejection frequency is 50kHz, the printing speed is 50μm / s, the line width control accuracy is ±2μm, and the dot matrix density is 1200DPI. The ink supply pressure is 0.4MPa, the temperature is 30±1℃, and the system features interlaced scanning and real-time reprinting of broken lines (threshold: missing length > 0.5μm).

[0153] Step 3: Mask curing

[0154] UV curing transfer speed 2m / min, single curing time 8 seconds, UV light source intensity 1000mJ / cm², hard film hardness 3H; thermosetting auxiliary temperature 150℃, heating rate 10℃ / min, constant temperature 15 minutes, adhesion 4N / μm.

[0155] Step 4: Etching

[0156] Temperature control at 60℃, ultrasonic frequency at 40kHz, power density at 1.5W / cm², etching solution flow rate at 0.5m / s; etching time at 5 minutes (line width at 30μm), with real-time monitoring of concentration and depth (deviation ±1.5μm).

[0157] Step 5: Remove mask and clean / dry

[0158] Mask removal solution: 25% potassium carbonate aqueous solution, temperature 60℃, ultrasonic frequency 60kHz, power density 0.8W / cm², immersion time 6 minutes (mask thickness 12μm); ultrasonic cleaning with deionized water (50kHz, 0.2MPa) for 3 minutes, followed by pure water spraying (0.5MPa) for 3 minutes; hot air drying at 90℃, wind speed 3.0m / s, humidity ≤0.3% and temperature difference ≤2℃ (approximately 10 minutes).

[0159] Equipment configuration: granite base support platform, three-axis movement accuracy ±1μm; inkjet module piezoelectric printhead (minimum ink droplet 1pl), online AOI inspection (resolution 0.5μm); curing device: UV-LED light source (365nm), thermosetting module equipped with infrared temperature measurement closed-loop control.

[0160] Table 1 shows a comparison of specific implementation methods and their technical advantages:

[0161] Dimension Example 2 (thick line width) Example 3 (Fine Line Width) Core Objectives Uniform etching, high adhesion Micrometer-level precision, low roughness Key differences - Lower lattice density (600 DPI) - Longer etching time (8 min) - Higher lattice density (1200 DPI) - More stringent alignment accuracy (±2 μm) Improved yield Increased from 90% to 95% From 85% to 96% Applicable materials Alumina ceramics (thick film process) Aluminum nitride ceramics (thin film process)

[0162] Table 1

[0163] As shown in Table 1, Examples 2 and 3 achieve stability in mass production through standardized parameters, making them suitable for cost-sensitive low-to-mid-end scenarios. They meet the needs of high-end applications through extreme precision control (such as ±1.5μm etching depth deviation), making them particularly suitable for high-value-added precision electronic devices. They achieve real-time defect warning through a multi-dimensional quality monitoring system (such as standard deviation of broken wire quantity and printing quality coefficient J). Combined with closed-loop control of process parameters, they significantly reduce scrap rate and improve production efficiency.

[0164] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-precision etching method for ceramic circuit boards based on inkjet masks, characterized in that, include: Step 1: Wash the ceramic circuit board to be processed by spraying with a combination of high-purity water and inorganic cleaning agent and then dry it, strictly controlling the concentration, time and temperature parameters of the cleaning solution; Step 2: Place the cleaned ceramic circuit board on the support platform and align the graphic reference using laser alignment. Start the inkjet mask module and print the graphic inkjet mask on the surface of the ceramic circuit board according to the input graphic file. During the printing process, control the nozzle ejection frequency, printing speed, line width and dot density. Step 3: After printing, the ink is initially cured using a UV curing unit, which uses a high-energy UV light source to promote the rapid formation of a hard film on the ink surface. Step 4: Transfer the ceramic circuit board that has been cured by the mask to the etching tank assembly. Select the etching solution according to the etching requirements and set the etching time, liquid temperature and ultrasonic vibration intensity. During the etching process, selectively etch the areas not covered by the mask. Step 5: After etching is completed, the ceramic circuit board is sent to the cleaning and drying module. The mask pattern is dissolved by the mask remover, and the removal process is accelerated by ultrasonic assistance. After the removal process is completed, the board surface is cleaned by spraying pure water and dried by hot air circulation. Step two specifically includes: The ceramic circuit board is placed in the positioning area of ​​the support platform, and the multi-point adsorption mechanism is activated to fix the ceramic circuit board under a vacuum negative pressure of -0.08 to -0.1MPa. Then, the laser alignment system is triggered, and a green laser with a wavelength of 532nm is used to scan and identify the cross-shaped or circular reference marks with a diameter of 0.1-0.3μm on the ceramic circuit board. The position deviation is calculated by the image recognition algorithm, and the support platform is driven to perform three-axis fine adjustment. Based on the characteristics of the input graphic file, the preset inkjet process parameter group is called, and the printhead ejection frequency is set to 20-50kHz, the printing speed to 50-100μm / s, the line width control accuracy to ±3μm, and the dot matrix density to 300-1200DPI. UV-curable mask ink is delivered to the printhead assembly, the ink supply pressure is maintained at 0.2-0.4MPa, the temperature is controlled at 30±2℃, and the graphic is printed using an interlaced scanning method. The printing quality is monitored in real time during the printing process, and online reprinting is performed for defects such as broken lines and exposed copper. Among these features, real-time monitoring of print quality during the printing process, and issuing alarms when print quality is abnormal, includes: The number of broken lines and the length of missing lines corresponding to the location of the broken lines are monitored in real time during the printing process. The total value of the missing length of the broken line is obtained according to the missing length of the broken line corresponding to the broken line location during each printing process. The ratio of the total length of the broken lines to the total length of the printing thread is calculated to obtain the length ratio coefficient between the total length of the broken lines and the total length of the printing thread. Filter the locations of broken wires; The missing length of the broken line at each broken line location is compared with the preset broken line length threshold. Filter out the locations of broken lines whose missing length exceeds a preset broken line length threshold, and use them as target broken line locations; Based on the target break location, obtain the straight-line distance between the center points of the break between any two target break locations; The length ratio coefficient between the total length of the missing lines and the total length of the printing thread is used in conjunction with the straight-line distance between the center points of the missing lines at every two target missing line locations to determine whether the printing quality of the current printing process meets the quality requirements, and an abnormal alarm is issued when the printing quality of the current printing process does not meet the quality requirements.

2. The high-precision etching method for ceramic circuit boards based on inkjet masks as described in claim 1, characterized in that, Step one also includes: Deionized water is used as the high-purity water raw material. The inorganic cleaning agent is a 5%-10% sodium hydroxide and sodium carbonate mixed solution with a mass ratio of sodium hydroxide to sodium carbonate of 3:

2. The cleaning solution is prepared by mixing high-purity water and inorganic cleaning agent in a volume ratio of 9:

1. The temperature of the mixed solution is controlled at 40-50℃, the stirring speed is 200-300 rpm, and the stirring is continued for 15-20 minutes to ensure that the cleaning solution is mixed evenly. The prepared cleaning solution is sprayed bidirectionally onto the ceramic circuit board at a pressure of 0.3-0.5 MPa for 8-12 minutes, while maintaining the cleaning solution temperature at 45±2℃. After the cleaning is completed, the ceramic circuit board is transferred to a hot air drying oven with a hot air temperature of 80-90℃, a wind speed of 1.5-2.0 m / s, and a drying time of 15-20 minutes to ensure that the residual moisture on the surface of the ceramic circuit board is completely evaporated and that the temperature difference between the surface of the circuit board and the ambient temperature does not exceed 5℃.

3. The high-precision etching method for ceramic circuit boards based on inkjet masks as described in claim 1, characterized in that, The print quality of the current printing process is determined by using the ratio coefficient between the total length of missing lines and the total length of the printing thread, combined with the straight-line distance between the center points of the missing lines at every two target missing line locations. This includes: The printing area is divided into grids according to the preset grid size to obtain multiple grid areas corresponding to the printing area; Extract the number of broken lines corresponding to each grid region; The standard deviation of the number of broken lines in multiple grid regions corresponding to the printing area is obtained based on the number of broken lines appearing in each grid region. The standard deviation of the number of broken wires is normalized to obtain the normalized standard deviation of the number of broken wires. Extract the length ratio coefficient between the total length of broken or missing lines and the total length of the printing thread; Extract the straight-line distance between the center points of the broken lines at every two target broken line locations; The straight-line distance between the center points of the broken lines at every two target broken line locations is normalized using a preset straight-line distance reference value to obtain the normalized straight-line distance; wherein the preset straight-line distance reference value has a range of 1.27D. max -1.53D max And, D max This represents the maximum straight-line distance between the center points of any two target break points; The print quality coefficient is obtained using the normalized standard deviation of the number of broken lines, the length ratio coefficient, and the normalized straight-line distance. The print quality coefficient is compared with a preset print quality coefficient threshold. When the print quality coefficient is lower than the preset print quality coefficient threshold, it is determined that the print quality of the current printing process does not meet the quality requirements.

4. The high-precision etching method for ceramic circuit boards based on inkjet masks as described in claim 1, characterized in that, Step three also includes: The inkjet-printed ceramic circuit board is fed into the UV curing unit via a carrier platform. A multi-band high-energy UV light source is turned on, and the ceramic circuit board passes through the light source at a transmission speed of 2-5 m / min. The curing time for each pass is controlled at 3-8 seconds, so that a hard film with a hardness of ≥2H is quickly formed on the surface of the mask ink, which inhibits ink diffusion. After initial curing, the ceramic circuit board is transferred to the thermosetting auxiliary module. The module temperature is set to 120-150℃, the heating rate is controlled at 5-10℃ / min, and the temperature is maintained for 15-30 minutes to improve the adhesion and etching resistance between the mask pattern and the surface of the ceramic circuit board. Microscopic inspection is performed on the cured mask pattern to check the edge clarity, surface flatness, and presence of bubbles or cracks. Areas with edge deviation >2μm, roughness Ra >0.5μm, or presence of bubbles or cracks are automatically marked as unqualified areas and returned to the UV curing unit for secondary curing.

5. The high-precision etching method for ceramic circuit boards based on inkjet masks as described in claim 1, characterized in that, Step four also includes: The etching solution is injected into the corrosion-resistant tank, and the temperature of the etching solution is adjusted to 45-65℃ by the constant temperature control unit. The vibration frequency of the ultrasonic exciter is set to 20-40kHz, and the power density is 0.5-1.5W / cm². The ceramic circuit board with the mask cured is vertically immersed in the etching solution, and the etching solution is circulated at a flow rate of 0.5-1.5m / s. At the same time, the ultrasonic vibration source is turned on. For patterns with a line width ≥50μm, the etching time is controlled at 5-10 minutes; for fine patterns with a line width <50μm, the etching time is controlled at 3-8 minutes. During the etching process, the concentration of the etching solution is monitored. When the concentration of the main component of the etching solution fluctuates by more than ±5%, the concentrate is automatically added for adjustment. The etching depth of the non-mask-covered area is monitored in real time using a laser reflective thickness gauge. When the preset etching depth is reached, the ceramic circuit board is removed from the etching tank and quickly transferred to the cleaning tank for spray cleaning. The cleaning water pressure is 0.2-0.4MPa and the cleaning time is 2-5 minutes to terminate the etching reaction and remove the residual etching solution on the surface.

6. The high-precision etching method for ceramic circuit boards based on inkjet masks as described in claim 1, characterized in that, Step five also includes: The etched ceramic circuit board is immersed in a demasking solution tank. The demasking solution is a potassium carbonate aqueous solution with a mass concentration of 15%-25% and the temperature is controlled at 50-60℃. At the same time, the ultrasonic auxiliary device is turned on, the ultrasonic frequency is set to 40-60kHz, and the power density is 0.3-0.8W / cm². The immersion time of the ceramic circuit board is adjusted according to the mask thickness. When the mask thickness is ≤10μm, the immersion time is controlled at 3-5 minutes; when the mask thickness is >10μm, the immersion time is controlled at 5-8 minutes, until the mask pattern is completely dissolved and detached from the ceramic circuit board surface. The ceramic circuit board after mask removal was ultrasonically cleaned with deionized water at a frequency of 30-50kHz for 2-3 minutes, with the water pressure maintained at 0.1-0.2MPa. The circuit board is sent into a pure water spray cleaning equipment and sprayed bidirectionally at a pressure of 0.3-0.5MPa for 3-5 minutes to ensure that the residual demasking liquid and impurities on the board surface are completely removed. Place the cleaned ceramic circuit board into a hot air circulating drying oven, set the oven temperature to 80-90℃, the hot air circulation speed to 2.0-3.0m / s, and the drying time to 10-15 minutes. During the drying process, the surface humidity of the circuit board is monitored in real time. Drying is stopped when the surface humidity drops to ≤0.5% and the temperature difference between the circuit board surface and the temperature inside the drying chamber does not exceed 3℃.

7. A high-precision etching apparatus for ceramic circuit boards based on inkjet masks, applied in the high-precision etching method for ceramic circuit boards based on inkjet masks as described in claim 1, characterized in that, include: The carrier platform (1), positioning components (2), inkjet mask module (3), and curing device; The support platform (1) is made of ceramic matrix composite material, and a three-axis moving component (11) is provided at the bottom of the support platform. The positioning component (2) includes a multi-point adsorption mechanism (21) and a laser alignment system (22). The multi-point adsorption mechanism (21) is located on the top of the support platform (1). The multi-point adsorption mechanism (21) fixes the ceramic circuit board by vacuum negative pressure to avoid displacement during inkjet or etching. The laser alignment system (22) is located on one side of the multi-point adsorption mechanism (21). The laser alignment system (22) is used to perform high-precision identification of key graphic marks on the ceramic circuit board to achieve precise alignment of inkjet graphics with the substrate. The inkjet mask module (3) includes a printhead assembly (31), an ink storage mechanism (32), and a pressurized supply system (33). The printhead assembly (31) is surrounded by an ink supply thermostatic conduit (34). The printhead assembly (31) is mounted on the inkjet mask module (3). An infrared detection probe (35) is provided on the side of the printhead assembly (31) near the support platform (1). The infrared detection probe (35) is used to monitor the printing quality in real time during the printing process and to reprint online for broken lines and exposed copper defects based on the quality monitoring results. The printhead assembly (31) is connected to the ink storage mechanism (32) through the pressurized supply system (33).

8. The high-precision etching equipment for ceramic circuit boards based on inkjet masks as described in claim 7, characterized in that, The curing device is located downstream of the inkjet mask module. The curing device includes an ultraviolet curing unit (41) and a thermosetting auxiliary module (42). The ultraviolet curing unit (41) adopts a multi-band high-energy UV light source, and the thermosetting auxiliary module (42) is a constant temperature heating chamber.

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