A manufacturing process combining dry and wet methods for a multilayer chip inductor component

Abstract

The present invention relates to a manufacturing process combining dry and wet methods for laminated chip inductor components, belonging to the technical field of laminated chip inductor production. It includes the following steps: S1: Slurry preparation; S2: Protective film preparation; S3: Printing; S4: Casting; S5: Film detection; S6: Establishing a quality optimization system; S7: Parameter adjustment, enabling the quality optimization system to analyze the input parameters to obtain the thickness convergence rate, overshoot, and steady-state error values; S8: Parameter determination, adjusting the casting speed and doctor blade gap according to the thickness convergence rate, overshoot, and steady-state error values; S9: Lamination; S10: Covering with an upper protective film; S11: Laminating; S12: Cutting; S13: Debinding; S14: Sintering. The present invention solves the problems that in the process of preparing existing laminated chip inductor components, the dry method has insufficient magnetic properties or the wet method is prone to uneven thickness.

Description

Technical Field

[0001] The present invention belongs to the technical field of the production of multilayer chip inductors, and particularly relates to a manufacturing process combining dry and wet methods for multilayer chip inductor components. Background Art

[0002] Chip inductors are one of the most widely used chip components in the electronics industry. With the development of the domestic chip inductor industry, their production processes have become increasingly mature. To meet the growing demand for components, electronic components are developing towards miniaturization, high frequency, high power, and low power consumption.

[0003] Multilayer chip high-power inductors are one of the most effective components for preventing electromagnetic interference. They can not only carry a large DC current but also absorb power supply noise well. The surface-mounted chip structure meets the requirements of new electronic devices for small size and light weight, and is particularly suitable for the power supply part to eliminate electromagnetic interference.

[0004] Currently, the manufacturing methods of multilayer chip inductors at home and abroad generally fall into the following categories, and their principles and characteristics are different. The all-wet manufacturing method: Ferromagnetic or ceramic dielectric materials are mixed with adhesives to form a slurry suitable for waterfall flow. Under mechanical drive, a film of a certain thickness is formed on a carrier plate, and then conductive wire electrode slurry is printed. Then, inter-turn connection slurry is printed at the line electrodes to form a bump. When flowing the dielectric film, connection through-holes are formed in the film at the bump. Then, conductive wire electrodes are printed at the through-holes to ensure good inter-turn connection. After repeating the process, an inductor structure of a certain thickness is formed. In addition, there is the lamination through-hole method (all-dry method). The all-dry method usually compresses powders into shapes by dry pressing, cold isostatic pressing, etc. Wet process - raw materials: Magnetic materials in the form of slurry are usually made by mixing magnetic powders with organic solvents, adhesives, etc. However, the density of the all-dry method is relatively low because it is difficult to completely remove air during dry pressing, so the magnetic properties are relatively low. However, because the forming process is relatively precise and the equipment and process are relatively simple, the cost is relatively low. In the wet method, the adhesive in the slurry helps to increase the forming density, so the magnetic properties are relatively high. However, due to the easy occurrence of uneven thickness during the casting and coating processes, and the relatively complex equipment and process, and the relatively high cost of slurry preparation, the production cost of the wet method is relatively high. Summary of the Invention

[0005] To solve the above problems existing in the prior art, the present invention provides a manufacturing process combining dry and wet methods for multilayer chip inductor components, which solves the problems of insufficient magnetic properties in the dry method or easy occurrence of uneven thickness in the wet method during the preparation of existing multilayer chip inductor components.

[0006] The object of the present invention can be achieved through the following technical solutions: A manufacturing process combining dry and wet methods for multilayer chip inductor components, comprising the following steps:

[0007] S1: Slurry preparation, mixing materials in proportion and milling and homogenizing them by ball milling;

[0008] S2: Preparation of protective film, making upper and lower protective films from the slurry by the dry method;

[0009] S3: Printing, printing the inner electrode slurry onto the lower protective film by screen printing;

[0010] S4: Casting, coating a film on the printed substrate by a casting machine to form a dielectric layer;

[0011] S5: Film sheet detection, detecting the thickness and flatness of the film sheet through the detection module in the casting machine;

[0012] S6: Establishing a quality optimization system, inputting the error value, casting speed, and squeegee gap parameters obtained by comparing the detection results of the detection module with the preset results into the quality optimization system;

[0013] S7: Parameter adjustment, enabling the quality optimization system to analyze the input parameters to obtain the thickness convergence rate, overshoot, and steady-state error value;

[0014] S8: Parameter determination, adjusting the casting speed and squeegee gap according to the thickness convergence rate, overshoot, and steady-state error value;

[0015] S9: Laminating, continuing to print and coat a layer of film according to the preset route with the parameters adjusted in step S8, and cycling in sequence until the lead-out terminal electrode is printed;

[0016] S10: Covering with the upper protective film, covering the upper protective film on the top surface of the laminated inductor;

[0017] S11: Laminating, packing the laminated blocks with a laminating bag, evacuating and encapsulating, and then pressurizing by an isostatic pressing method to make the layers in the blocks combine more closely and tightly;

[0018] S12: Cutting, cutting the laminated blocks into independent capacitor green bodies;

[0019] S13: Debinding, placing the capacitor green bodies on a firing plate, and baking at a high temperature according to the preset temperature curve to remove the binder and organic substances in the chips;

[0020] S14: Sintering, performing high-temperature treatment on the chips after debinding.

[0021] As a preferred technical solution of the present invention, in step S10, when covering the upper protective film, first apply a layer of dielectric layer on the lead-out terminal electrode by wet casting.

[0022] As a preferred technical solution of the present invention, the thickness of the dielectric layer on the bottom surface of the upper protective film is determined according to the number of printing times.

[0023] As a preferred technical solution of the present invention, in step S5, the detection module detects the thickness and flatness of the film sheet through a laser rangefinder.

[0024] As a preferred technical solution of the present invention, in step S7, the quality optimization system includes a feedforward control module. The feedforward control module predicts the thickness and flatness of the film sheet within a future predetermined time step and optimizes the control input to minimize the prediction error.

[0025] As a preferred technical solution of the present invention, in step S8, the quality optimization system adjusts the thickness convergence speed in advance through the feedforward control module, controls the overshoot through a fuzzy control algorithm, and eliminates the steady-state error by using a PID controller for the steady-state error value.

[0026] As a preferred technical solution of the present invention, the quality optimization system regularly generates a historical record report of the film sheet thickness, flatness, casting parameters, and environmental conditions for subsequent analysis and quality control.

[0027] As a preferred technical solution of the present invention, in step S5, the casting machine also detects the environmental temperature and humidity.

[0028] As a preferred technical solution of the present invention, in step S3, the position of the lower protective film is in the same position every time printing is performed.

[0029] As a preferred technical solution of the present invention, in step S1, the milled slurry is filtered.

[0030] The beneficial effects of the present invention are as follows: By detecting the thickness and flatness of each cast film sheet, and then adjusting the casting speed and the gap of the doctor blade through the thickness convergence speed, overshoot, and steady-state error value, the problem of uneven thickness during the casting and coating processes is reduced, thereby solving the problem of insufficient dry magnetic properties when the existing multilayer chip inductor components are prepared by the dry method or the problem of easy uneven thickness when prepared by the wet method. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings.

[0032] Figure 1 It is a manufacturing process flow chart of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] To further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following will, in conjunction with the accompanying drawings and preferred embodiments, elaborate in detail on the specific implementation manners, structures, features and their effects of the present invention as follows.

[0034] Please refer to Figure 1 , this embodiment provides a manufacturing process combining dry and wet methods for a multilayer chip inductor component, including the following steps:

[0035] S1: Slurry preparation, mixing materials in proportion and milling and homogenizing them through ball milling;

[0036] S2: Preparation of protective film, making upper and lower protective films from the slurry by dry method;

[0037] S3: Printing, using the lower protective film as a substrate, and then printing the inner electrode slurry onto the lower protective film through screen printing;

[0038] S4: Casting, coating a thin film on the printed substrate through a casting machine to form a dielectric layer;

[0039] S5: Film inspection, detecting the thickness and flatness of the film through the detection module in the casting machine;

[0040] S6: Establishing a quality optimization system, inputting the error value, casting speed and doctor blade gap parameters obtained by comparing the detection results of the detection module with the preset results into the quality optimization system;

[0041] S7: Parameter adjustment, enabling the quality optimization system to analyze the input parameters to obtain the thickness convergence speed, overshoot and steady-state error value;

[0042] S8: Parameter determination, adjusting the casting speed and doctor blade gap according to the thickness convergence speed, overshoot and steady-state error value;

[0043] S9: Laminating, continuing to print and coat a thin film in accordance with the preset circuit according to the parameters adjusted in step S8, and cycling in sequence until the lead-out terminal electrodes are printed;

[0044] S10: Covering with upper protective film, covering the top surface of the laminated inductor with the upper protective film;

[0045] S11: Laminating, packing the laminated block with a laminating bag, evacuating and encapsulating it, and then pressurizing it by an isostatic pressing method to make the layers in the block combine more closely and tightly;

[0046] S12: Cutting, cutting the laminated block into independent capacitor green bodies;

[0047] S13: Debinding. Place the green capacitor on a carrier plate and bake it at a high temperature according to a preset temperature curve to remove the binder and organic substances in the chip. By removing the binder and organic substances in the chip, it is possible to avoid delamination and cracking of the product caused by the rapid volatilization of organic substances during firing, so as to ensure that a complete porcelain piece with the required shape is fired.

[0048] S14: Sintering. Subject the chip after debinding to high-temperature treatment to make it a ceramic body with high mechanical strength and excellent electrical properties.

[0049] When preparing multilayer chip inductor components, whether using the dry method or the wet method for preparation, it is necessary to add protective layers on the upper and lower surfaces of the inductor. The protective layers can prevent the inductor from being scratched, collided and other physical damages during transportation and installation. The protective layers increase the overall mechanical strength of the inductor, making it more durable. They can also prevent moisture from penetrating into the inductor, avoiding short circuits or performance degradation caused by dampness, and can also prevent corrosion and endow the inductor with good insulation performance. Currently, the existing protective layers are usually prepared using ceramic protection sheets. However, traditional ceramic production requires high-temperature sintering, with high energy consumption, and the ceramic protection sheets are relatively heavy, which will increase the weight of the entire inductor and is not conducive to the design of thin and light products.

[0050] Therefore, in the present invention, a slurry is prepared into a thin film by the dry method as the protection sheet. Since the protective film made by the dry method is lighter than the traditional ceramic protection sheet, this can reduce the weight of the overall capacitor, thus achieving the thin and light design of electronic products. Moreover, the dry film-making process is generally simpler than the traditional ceramic production process, with a faster production speed, thereby improving the overall production efficiency and reducing the production cost. This is because traditional ceramic production requires high-temperature sintering with high energy consumption, while dry film-making is usually formed at room temperature or a lower temperature, thus reducing energy consumption. In addition, the protective film made by the dry method can usually be designed into a thinner and better-insulating material, and its excellent electrical insulation can provide better reliability.

[0051] However, in the inductor prepared by the dry method, since it is difficult to completely remove air during the dry pressing process in the dielectric layer, the magnetic properties are relatively low, which cannot meet the production requirements of small, high-density, and high-integration inductors. Although the wet method can achieve high density to improve magnetic properties, during the casting and coating processes, problems such as uneven thickness are likely to occur, resulting in higher production costs. Although the thickness of the film can be adjusted by adjusting the parameters of the existing casting machine during production, fine-tuning the parameters of the casting machine requires a large amount of experiments and time, which will lead to a reduction in production efficiency. Moreover, even after adjustment, consistency differences between batches or during the production process may still occur. Therefore, in order to solve the problem of high production costs caused by uneven thickness during the casting and coating processes.

[0052] After each layer of diaphragm is coated, the thickness and flatness of the diaphragm during the coating process are detected. Then, the detection results are compared with the preset results to obtain the error value. At the same time, the casting speed of the casting machine and the clearance parameter of the doctor blade during this coating process are input into the quality optimization system. The quality optimization system uses fuzzy algorithm and PID controller to analyze according to the input parameters, so as to obtain the thickness convergence speed, overshoot and steady-state error value.

[0053] The thickness convergence speed refers to the time or rate required for the diaphragm thickness to adjust from the initial value to the target value. It reflects the rapidity of the control system response, that is, how quickly the system can approach the predetermined diaphragm thickness. Therefore, during the control process, the diaphragm thickness should approach the target value at a faster speed and should not have excessive fluctuations. The overshoot is the degree to which the diaphragm thickness exceeds the target value during the adjustment process of the control system. Specifically, it is the difference between the maximum value reached by the diaphragm thickness for the first time and the target value. Therefore, the overshoot should be as small as possible to avoid unnecessary fluctuations when the diaphragm thickness reaches the target value. The steady-state error is the difference between the diaphragm thickness and the target value after the control system reaches the stable state. It reflects the accuracy of the system in the stable state. Therefore, the steady-state error should be as close to zero as possible to ensure that the diaphragm thickness is consistent with the target value.

[0054] Therefore, by detecting the thickness and flatness of each cast diaphragm, and then adjusting the casting speed and the clearance of the doctor blade through the thickness convergence speed, overshoot and steady-state error value, the problem of uneven thickness during the casting and coating processes can be reduced, thus solving the problem of insufficient dry magnetic properties or easy uneven thickness during wet preparation when preparing existing multilayer chip inductor components.

[0055] In order to make the combination between the printed silver layer and the magnet easier, in this embodiment, in step S10, when covering the protective film, a dielectric layer is first cast wet on the lead terminal electrode. After printing the required number of turns of the coil and then printing the lead terminal electrode, a wet layer is cast before finally covering the protective film, so that the printed silver layer can be more firmly bonded to the upper protective film, extending the service life of the protective layer and ensuring the stable performance of the inductor during long-term use.

[0056] Since inductors with different numbers of printed turns have different magnetic properties, and the more turns are printed, the stronger the magnetic properties, and the better the insulation performance required for isolation. Therefore, in one embodiment, the thickness of the dielectric layer on the bottom surface of the upper protective film is determined according to the number of printing times. By different preparation designs, the specific thickness of the dielectric layer is determined, so as to ensure that the inductor has good insulation, prevent short circuits between the inductor and other components, and ensure the safe operation of the circuit.

[0057] In order to accurately evaluate the thickness and surface flatness of the diaphragm, and thus reduce the performance differences caused by uneven thickness. In one embodiment, in step S5, the detection module uses a laser rangefinder to detect the thickness and flatness of the diaphragm. The non-contact characteristic of the laser rangefinder can effectively avoid mechanical damage or contamination to the surface of the diaphragm, maintain the integrity and performance of the diaphragm, and the laser rangefinder can provide very high measurement accuracy, so that the quality optimization system can accurately adjust the production parameters according to the detection results, improving production efficiency and product quality.

[0058] In order to enhance the prediction error of the quality optimization system and its adaptability to changing environments and parameter fluctuations. In one embodiment, in step S7, the quality optimization system includes a feedforward control module. The feedforward control module predicts the diaphragm thickness and flatness within a future predetermined time step, and optimizes the control input to minimize the prediction error. By setting the target values of the diaphragm thickness and flatness, and then using optimization algorithms (such as gradient descent, genetic algorithm) to adjust the control inputs (casting speed, doctor blade gap) to minimize the prediction error, thereby improving the accuracy of diaphragm production and enhancing the system's adaptability to changing environments and parameter fluctuations.

[0059] Since the prediction error is reduced through the feedforward control module to improve the accuracy of diaphragm production, and the feedforward control module can predict the future change trend of the diaphragm thickness according to the current state, and the thickness convergence speed needs to converge quickly to reduce the change range of the diaphragm thickness and make it closer to the target value faster. Therefore, in one embodiment, in step S8, the quality optimization system adjusts the thickness convergence speed in advance through the feedforward control module, the overshoot is controlled by the fuzzy control algorithm, and the steady-state error value is eliminated by the PID controller. By analyzing the development of the diaphragm thickness through the feedforward control module, the system can evaluate the required adjustment intensity in advance, and on the basis of prediction, automatically adjust the control inputs such as the casting speed and the doctor blade pressure to achieve a faster convergence speed. By adjusting in advance, the change range of the diaphragm thickness can be reduced, making it closer to the target value faster. Through the fuzzy inference mechanism, the state and change rate of the current diaphragm thickness are mapped to the corresponding control output adjustment, intelligently reducing the overshoot, thereby providing flexible control, reducing the overshoot phenomenon of the system. At the same time, the PID controller runs continuously to ensure that there is no steady-state error when the diaphragm reaches the target thickness. This multi-level control method not only improves the response speed of the system, but also enhances the stability and accuracy of the control, thus meeting the requirements of high-quality diaphragm production.

[0060] Since the feedforward control module can also identify and correct potential quality problems by analyzing historical data to ensure that each batch of diaphragms meets the quality standards. Therefore, in one embodiment, to ensure the high quality and consistency of the diaphragm products, the quality optimization system regularly generates historical record reports of the diaphragm thickness, flatness, casting parameters and environmental conditions for subsequent analysis and quality control. By regularly generating historical record reports of the diaphragm thickness, flatness, casting parameters and environmental conditions, valuable data support is provided for quality control and subsequent analysis. Effective data management and analysis enable the quality optimization system to continuously improve the production process and ensure the high quality and consistency of the diaphragm products.

[0061] When preparing the dielectric layer by the wet method, in addition to the thickness and flatness of the diaphragm affecting the performance of the inductor, the temperature and humidity of the environment will also affect the fluidity and viscosity of the slurry. A higher temperature will reduce the viscosity of the slurry, thus making the diaphragm thinner; a lower temperature will increase the viscosity of the slurry, making the diaphragm thicker. Humidity: The environmental humidity will also affect the drying process of the slurry. High humidity may cause the surface of the diaphragm to be uneven, affecting the thickness control. Therefore, in one embodiment, in step S5, the casting machine also detects the environmental temperature and humidity. By implementing the detection and control of the environmental temperature and humidity in the casting machine, the quality optimization system can effectively reduce the influence of these factors on the diaphragm thickness and flatness, thereby improving the production quality and consistency of the diaphragm, enhancing the stability of the production process, and providing a more reliable guarantee for the performance of the inductor.

[0062]

[0062] In order to ensure the printing accuracy during the printing and casting process and that the overall quality of the film is not affected by additional factors, in one embodiment, in step S3, the position of the lower protective film is at the same position during each printing. By ensuring that the position of the lower protective film can be accurately placed at the same position during each printing, it is avoided that the movement of the substrate causes the film to shift in position, thereby improving the consistency of the film and ensuring the overall quality of the film.

[0063] During the casting process, in addition to the casting speed, the doctor blade gap, and the environmental temperature and humidity affecting the quality of the film, the uniformity of the slurry will also affect the fluidity of the slurry. Therefore, in order to ensure the insulation performance of the film while improving the quality of the film, in one embodiment, in step S1, the milled slurry is filtered. By filtering, large particle impurities and insoluble substances in the slurry are removed, improving the purity and uniformity of the slurry, thereby ensuring the quality of the film in the subsequent production process and providing a guarantee for the performance of the final product.

[0064]

[0064] The above are only the preferred embodiments of the present invention and do not impose any formal restrictions on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A manufacturing process combining dry and wet methods for a multilayer chip inductor component, characterized in that, It includes the following steps: S1: Slurry preparation, mixing materials in proportion and milling and homogenizing them by ball milling; S2: Protective film preparation, making upper and lower protective films from the slurry by the dry method; S3: Printing, printing the inner electrode slurry onto the lower protective film by screen printing; S4: Casting, coating a film on the printed substrate by a casting machine to form a dielectric layer; S5: Film inspection, inspecting the thickness and flatness of the film through the inspection module in the casting machine; S6: Establish a quality optimization system, inputting the error value obtained by comparing the inspection results of the inspection module with the preset results, the casting speed and the blade gap parameters into the quality optimization system; S7: Parameter adjustment, enabling the quality optimization system to analyze the input parameters to obtain the thickness convergence speed, overshoot and steady-state error value; S8: Parameter determination, adjusting the casting speed and the blade gap according to the thickness convergence speed, overshoot and steady-state error value; S9: Laminating, continuing to print and coat a film in accordance with the preset route according to the parameters adjusted in step S8, and cycling in sequence until the lead-out terminal electrode is printed; S10: Covering with the upper protective film, covering the upper surface of the inductor completed by lamination with the upper protective film; S11: Laminating, packing the laminated block with a lamination bag, evacuating and encapsulating, and pressurizing by an isostatic pressing method to make the layers in the block combine more closely and tightly; S12: Cutting, cutting the laminated block into independent capacitor green blanks; S13: Debinding, placing the capacitor green blank on a bearing plate, and baking it at a high temperature according to the preset temperature curve to remove the binder and organic substances in the chip; S14: Sintering, performing high-temperature treatment on the chip after debinding; In step S7, the quality optimization system includes a feedforward control module, which predicts the film thickness and flatness within a future predetermined number of time steps and optimizes the control input to minimize the prediction error; In step S8, the quality optimization system adjusts the thickness convergence speed in advance through the feedforward control module, controls the overshoot through a fuzzy control algorithm, and eliminates the steady-state error of the steady-state error value by using a PID controller; By preparing the slurry into a film by the dry method as a protective sheet, since the protective film made by the dry method is lighter than the traditional ceramic protective sheet, this can reduce the weight of the overall capacitor, thus achieving the thinning and lightening of electronic products, and the dry film-making process is generally simpler than the traditional ceramic sheet-making process and has a faster production speed, thereby improving the overall production efficiency and reducing the production cost. In step S10, when covering the upper protective film, first apply a layer of dielectric layer on the lead-out terminal electrode by wet casting. The thickness of the dielectric layer on the bottom surface of the upper protective film is determined according to the number of printings. S14： In step S5, the inspection module inspects the thickness and flatness of the film through a laser rangefinder. The quality optimization system regularly generates a historical record report of the film thickness, flatness, casting parameters and environmental conditions for subsequent analysis and quality control. In step S5, the casting machine also detects the environmental temperature and humidity. In step S3, the position of the lower protective film is in the same position every time printing is performed.

2. The manufacturing process combining dry and wet methods for a stacked chip inductor component according to claim 1, characterized in that: ​ 3. The manufacturing process combining dry and wet methods for a stacked chip inductor element according to claim 2, characterized in that: ​ 4. The manufacturing process combining dry and wet methods for a stacked chip inductor component according to claim 1, characterized in that: ​ 5. The manufacturing process combining dry and wet methods for a laminated chip inductor component according to claim 1, characterized in that: ​ 6. The manufacturing process of a laminated chip inductor element combining dry and wet methods according to claim 1, characterized in that: ​ 7. A manufacturing process for a laminated chip inductor element combining dry and wet methods, as described in claim 1, characterized in that: ​ 8. The manufacturing process combining dry and wet methods for a laminated chip inductor component according to claim 1, characterized in that: In step S1, the milled slurry is filtered.

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