Dry and wet method combined manufacturing process for laminated chip inductor element

Abstract

The invention relates to a dry and wet method combined manufacturing process for a laminated chip inductor element, and belongs to the technical field of laminated chip inductor production. Comprising the following steps: S1, preparing slurry; s2, preparing a protective film; s3, printing; s4, tape casting; s5, membrane detection; s6, establishing a quality optimization system; s7, adjusting parameters, and enabling the quality optimization system to analyze the input parameters to obtain a thickness convergence rate, an overshoot and a steady-state error value; s8, parameters are determined, and the tape casting speed and the scraper clearance are adjusted according to the thickness convergence speed, the overshoot and the steady-state error value; s9, performing lamination; s10, covering with a protective film; s11, laminating is carried out; s12, cutting is conducted; s13, glue discharging is carried out; and S14, sintering is conducted. The problems that in the preparation process of an existing laminated chip inductor element, the magnetic performance is insufficient when a dry method is adopted or the thickness is not uniform when a wet method is adopted for preparation are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of laminated chip inductor production, and in particular relates to a dry-wet combined manufacturing process for laminated chip inductor components. Background Art

[0002] Chip inductors are one of the most widely used chip components in the electronics industry. Their production technology has become increasingly mature with the development of the domestic chip inductor industry. In order to meet people's increasingly high demand for components, electronic components are developing towards miniaturization, high frequency, high power and low power consumption.

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

[0004] At present, there are generally the following methods for making multilayer chip inductors at home and abroad, and their principles and characteristics are different. Full wet method: add ferrite or ceramic dielectric materials and adhesives to make a slurry suitable for waterfall flow, and flow a certain thickness of membrane on the carrier under mechanical drive, and then print the conductive wire electrode slurry, and then print the turn-to-turn connection slurry at the line electrode to form a convex point, and flow the dielectric membrane to form a connecting through hole at the convex point, and then print the conductive wire electrode at the through hole to make the turn-to-turn connection good. After repeated cycles, an inductor structure of a certain thickness is formed. In addition, there is also a stacked through-hole method (full dry method). The full dry method usually presses the powder into shape by dry pressing, cold isostatic pressing, etc. Wet process•Raw materials: Magnetic materials in the form of slurry are usually mixed with magnetic powders and organic solvents, adhesives, etc. However, the density of the fully dry process is lower because it is difficult to completely exclude air during the dry pressing process, so the magnetic properties are relatively low. However, because the molding process is more precise, and the equipment and process are relatively simple, the cost is lower. The wet process has higher magnetic properties because the adhesive in the slurry helps to increase the molding density. However, because uneven thickness is prone to occur during the casting and coating process, the equipment and process are more complicated, and the slurry preparation cost is higher, resulting in a higher production cost for the wet process. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a dry-wet combined manufacturing process for a laminated chip inductor element, which solves the problem that the existing laminated chip inductor elements have insufficient magnetic properties when prepared by the dry method or are prone to uneven thickness when prepared by the wet method.

[0006] The object of the present invention can be achieved by the following technical solution: A dry-wet combined manufacturing process of a laminated chip inductor element comprises the following steps: S1: slurry preparation, mixing the materials according to the proportion and grinding and homogenizing by ball milling; S2: protective film preparation, the slurry is made into upper and lower protective films by dry method; S3: printing, printing the inner electrode slurry onto the lower protective film by screen printing; S4: Casting: a film is coated on the printed substrate by a casting machine to form a dielectric layer; S5: Film inspection: the thickness of the module and the flatness of the film are inspected by the inspection module in the casting machine; S6: Establish a quality optimization system, compare the detection result of the detection module with the preset result to obtain the error value, casting speed and scraper gap parameters, and input them into the quality optimization system; S7: Parameter adjustment, allowing the quality optimization system to analyze the input parameters to obtain thickness convergence speed, overshoot and steady-state error value; S8: Parameter determination, adjusting the casting speed and scraper gap according to the thickness convergence speed, overshoot and steady-state error value; S9: stacking, continuing to print and coat a layer of film according to the preset circuit according to the parameters adjusted in step S8, and repeating in sequence until the terminal electrode is printed; S10: Covering with an upper protective film: Covering the top surface of the laminated inductor with an upper protective film; S11: Lamination: pack the laminated blocks in a laminating bag, vacuum seal them, and apply pressure by isostatic pressing to make the layers in the blocks more tightly bonded and tight; S12: cutting, cutting the laminated blocks into independent capacitor green sheets; S13: Debinding, placing the capacitor green body on the firing plate, and baking it at high temperature according to a preset temperature curve to remove the adhesive and organic matter in the chip; S14: Sintering and high temperature treatment of the chip after debinding.

[0007] As a preferred technical solution of the present invention, in step S10, when covering with the protective film, a dielectric layer is firstly wet-cast on the lead-out terminal electrode.

[0008] 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.

[0009] As a preferred technical solution of the present invention, in step S5, the detection module detects the thickness and flatness of the diaphragm by using a laser rangefinder.

[0010] As a preferred technical solution of the present invention, in step S7, the quality optimization system includes a feedforward control module, which predicts the thickness and flatness of the membrane within a future predetermined time step and optimizes the control input to minimize the prediction error.

[0011] 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, the overshoot is controlled by the fuzzy control algorithm, and the steady-state error value is eliminated by the PID controller.

[0012] As a preferred technical solution of the present invention, the quality optimization system regularly generates historical record reports of film thickness, flatness, casting parameters and environmental conditions for subsequent analysis and quality control.

[0013] As a preferred technical solution of the present invention, in step S5, the casting machine also detects the ambient temperature and humidity.

[0014] As a preferred technical solution of the present invention, in step S3, the position of the lower protective film is at the same position during each printing.

[0015] As a preferred technical solution of the present invention, in step S1, the ground slurry is filtered.

[0016] The beneficial effects of the present invention are as follows: by detecting the thickness and flatness of each cast film, and then adjusting the casting speed and the gap of the scraper according to the thickness convergence speed, overshoot and steady-state error value, the occurrence of problems such as uneven thickness during the casting and coating processes is reduced, thereby solving the problem of insufficient magnetic properties of the existing laminated chip inductor components during the preparation process using a dry method or prone to uneven thickness when using a wet method. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0018] Figure 1 It is a manufacturing process flow chart of the present invention. DETAILED DESCRIPTION

[0019] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0020] See also Figure 1 This embodiment provides a dry-wet combined manufacturing process for a laminated chip inductor element, comprising the following steps: S1: slurry preparation, mixing the materials according to the proportion and grinding and homogenizing by ball milling; S2: protective film preparation, the slurry is made into upper and lower protective films by dry method; S3: printing, using the lower protective film as a substrate, and then printing the inner electrode slurry onto the lower protective film by screen printing; S4: Casting: a film is coated on the printed substrate by a casting machine to form a dielectric layer; S5: Film inspection: the thickness of the module and the flatness of the film are inspected by the inspection module in the casting machine; S6: Establish a quality optimization system, compare the detection result of the detection module with the preset result to obtain the error value, casting speed and scraper gap parameters, and input them into the quality optimization system; S7: Parameter adjustment, allowing the quality optimization system to analyze the input parameters to obtain thickness convergence speed, overshoot and steady-state error value; S8: Parameter determination, adjusting the casting speed and scraper gap according to the thickness convergence speed, overshoot and steady-state error value; S9: stacking, continuing to print and coat a layer of film according to the preset circuit according to the parameters adjusted in step S8, and repeating in sequence until the terminal electrode is printed; S10: Covering with an upper protective film: Covering the top surface of the laminated inductor with an upper protective film; S11: Lamination: pack the laminated blocks in a laminating bag, vacuum seal them, and apply pressure by isostatic pressing to make the layers in the blocks more tightly bonded and tight; S12: cutting, cutting the laminated blocks into independent capacitor green sheets; S13: Debinding, placing the capacitor green body on the firing plate, and baking it at high temperature according to the preset temperature curve to remove the adhesive and organic matter in the chip. By removing the adhesive organic matter in the chip, the rapid volatilization of organic matter during firing can be avoided to avoid product delamination and cracking, so as to ensure that the ceramic parts with the required shape are fired intact; S14: The chip after sintering and debinding is subjected to high temperature treatment to make it a ceramic body with high mechanical strength and excellent electrical properties.

[0021] When preparing multilayer chip inductor components, whether it is prepared by dry method or wet method, it is necessary to add protective layers on the upper and lower sides of the inductor. The protective layer can prevent the inductor from being physically damaged by scratches, collisions, etc. during transportation and installation. The protective layer increases the overall mechanical strength of the inductor, making it more durable. It can also prevent moisture from penetrating into the inductor to avoid short circuits or performance degradation caused by moisture. It can also prevent corrosion and make the inductor have good insulation properties. The existing protective layer is usually prepared by a ceramic protective sheet. However, traditional ceramic sheeting requires high-temperature sintering, high energy consumption, and the weight of the ceramic protective sheet is heavy, which will increase the weight of the entire inductor, which is not conducive to a lightweight design.

[0022] Therefore, the present invention prepares the slurry into a thin film by dry method as a protective film. Since the protective film made by the dry method is lighter than the traditional ceramic protective film, this can reduce the weight of the overall capacitor, thereby achieving lightweight and thin electronic products. In addition, the dry film making process is generally simpler than the traditional ceramic film making process and has a faster production speed, thereby improving overall production efficiency and reducing production costs. This is because traditional ceramic film making requires high-temperature sintering and has high energy consumption, while dry film making is usually formed at room temperature or lower temperatures, thereby reducing energy consumption. In addition, the protective film made by the dry method can usually be designed to be a thinner material with better insulation properties, and its excellent electrical insulation can provide better reliability.

[0023] However, since it is difficult to completely remove air from the dielectric layer of the inductor prepared by the dry method during the dry pressing process, the magnetic properties are relatively low and cannot meet the production needs of small, high-density, and highly integrated inductors. Although the wet method can achieve high density to improve the magnetic properties, problems such as uneven thickness are prone to occur during the casting and coating processes, resulting in high production costs. Although the thickness of the diaphragm can be adjusted by adjusting the parameters of the existing casting machine during production, fine-tuning the parameters of the casting machine requires a lot of experiments and time, which will lead to reduced production efficiency. Even after adjustment, there may still be consistency differences between batches or during the production process. Therefore, in order to improve the problem of uneven thickness that is prone to occur during the casting and coating processes and lead to high production costs.

[0024] The present invention detects the thickness and flatness of each layer of diaphragm during the coating process after coating is completed, and then compares the detection result with the preset result to obtain the error value. At the same time, the casting speed of the casting machine and the gap parameters of the scraper during the 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.

[0025] The thickness convergence rate 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's 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 rate and should not fluctuate too much. The overshoot refers to 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, so the overshoot should be as small as possible to avoid unnecessary fluctuations in the diaphragm thickness when the target value is reached. The steady-state error refers to the difference between the diaphragm thickness and the target value after the control system reaches a stable state. It reflects the accuracy of the system in a stable state, so the steady-state error should be as close to zero as possible to ensure that the diaphragm thickness is consistent with the target value.

[0026] Therefore, by detecting the thickness and flatness of the cast film each time, and then adjusting the casting speed and the gap of the scraper according to the thickness convergence speed, overshoot and steady-state error value, the occurrence of problems such as uneven thickness during the casting and coating process can be reduced, thereby solving the problem of insufficient magnetic properties of existing multilayer chip inductor components during the preparation process using the dry method or prone to uneven thickness when using the wet method.

[0027] In order to make it easier for the printed silver layer to be combined with the magnet, in this embodiment, in step S10, a dielectric layer is first wet-cast on the lead-out electrode when covering the protective film, and the lead-out electrode is printed after printing the required number of coils, and finally a wet-cast layer is cast before covering the protective film, so that the printed silver layer can be more firmly bonded to the upper protective film, thereby extending the service life of the protective layer and ensuring the stable performance of the inductor during long-term use.

[0028] Since the inductor has different magnetic properties when the number of printed circles is different, and the more circles are printed, the stronger the magnetic properties are, and the better the insulation performance required for isolation is, therefore, in order to ensure that the upper protective film can have good insulation performance, 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, and the specific thickness of the dielectric layer is determined by different preparation designs, thereby ensuring that the inductor has good insulation, preventing short circuits between the inductor and other components, and ensuring safe operation of the circuit.

[0029] In order to ensure accurate assessment of the thickness and surface flatness of the diaphragm, thereby reducing performance differences caused by uneven thickness, in one embodiment, in step S5, the detection module detects the thickness and flatness of the diaphragm using a laser rangefinder. The non-contact characteristics 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 production parameters according to the detection results to improve production efficiency and product quality.

[0030] 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, which predicts the thickness and flatness of the membrane within a predetermined time step in the future, and optimizes the control input to minimize the prediction error. By setting the target value of the membrane thickness and flatness, and then using an optimization algorithm (such as gradient descent, genetic algorithm) to adjust the control input (casting speed, scraper gap) to minimize the prediction error, the accuracy of membrane production is improved, and the system's adaptability to changing environments and parameter fluctuations is enhanced.

[0031] Since the prediction error is reduced and the accuracy of diaphragm production is improved by the feedforward control module, and the feedforward control module can predict the future trend of diaphragm thickness changes based on the current state, and the thickness convergence speed needs to achieve rapid convergence to reduce the variation of diaphragm thickness and make it approach 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, the steady-state error value uses the PID controller to eliminate the steady-state error, and the development of diaphragm thickness is analyzed by the feedforward control module. The system can evaluate the required adjustment force in advance, and automatically adjust the control inputs such as the casting speed and the scraper pressure based on the prediction to achieve faster convergence speed. The advance adjustment can reduce the variation of diaphragm thickness and make it approach the target value faster. Through the fuzzy reasoning mechanism, the current state and change rate of the diaphragm thickness are mapped to the corresponding control output adjustment, intelligently reducing the overshoot, thereby providing flexible control and reducing the overshoot phenomenon of the system. At the same time, the PID controller continues to run to ensure that the diaphragm has no steady-state error when it 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, thereby meeting the requirements of high-quality diaphragm production.

[0032] 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 quality standards, in order to ensure the high quality and consistency of diaphragm products, in one embodiment, the quality optimization system regularly generates historical record reports of diaphragm thickness, flatness, casting parameters and environmental conditions for subsequent analysis and quality control. By regularly generating historical record reports of diaphragm thickness, flatness, casting parameters and environmental conditions, valuable data support is provided for quality control and subsequent analysis. Effective data management and analysis can enable the quality optimization system to continuously improve the production process to ensure the high quality and consistency of diaphragm products.

[0033] When preparing the dielectric layer by 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. Higher temperature will reduce the viscosity of the slurry, thereby making the diaphragm thinner; lower temperature will increase the viscosity of the slurry, making the diaphragm thicker. Humidity: Ambient humidity will also affect the drying process of the slurry. High humidity may cause the surface of the diaphragm to be uneven, affecting thickness control. Therefore, in order to reduce the impact of ambient temperature and humidity on the diaphragm, in one embodiment, in step S5, the casting machine also detects the ambient temperature and humidity. By implementing the detection and control of ambient temperature and humidity in the casting machine, the quality optimization system can effectively reduce the impact of these factors on the thickness and flatness of the diaphragm, thereby improving the production quality and consistency of the diaphragm, and enhancing the stability of the production process, providing a more reliable guarantee for the performance of the inductor.

[0034] In order to ensure that the printing accuracy and the overall quality of the membrane will not be affected by additional factors during the printing and casting process, in one embodiment, in step S3, the position of the lower protective film is in the same position each time printing is performed. By ensuring that the position of the lower protective film is accurately placed in the same position each time printing is performed, the displacement of the membrane position caused by the movement of the substrate is avoided, thereby improving the consistency of the membrane and ensuring the overall quality of the membrane.

[0035] During the casting process, in addition to the casting speed, scraper gap and ambient temperature and humidity that affect the quality of the diaphragm, the uniformity of the slurry will also affect the fluidity of the slurry. Therefore, in order to ensure the insulation performance of the diaphragm while improving the quality of the diaphragm, in one embodiment, in step S1, the ground slurry is filtered to remove large particles of impurities and insoluble substances in the slurry, thereby improving the purity and uniformity of the slurry, thereby ensuring the quality of the diaphragm in the subsequent production process and providing a guarantee for the performance of the final product.

[0036] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A dry-wet method combined manufacturing process for a laminated chip inductor component, characterized in that: The following steps are involved: S1: slurry preparation, mixing the materials according to the proportion and grinding and homogenizing by ball milling; S2: protective film preparation, the slurry is made into upper and lower protective films by dry method; S3: printing, printing the inner electrode slurry onto the lower protective film by screen printing; S4: Casting: a film is coated on the printed substrate by a casting machine to form a dielectric layer; S5: Film inspection: the thickness of the module and the flatness of the film are inspected by the inspection module in the casting machine; S6: Establish a quality optimization system, compare the detection result of the detection module with the preset result to obtain the error value, casting speed and scraper gap parameters, and input them into the quality optimization system; S7: Parameter adjustment, allowing the quality optimization system to analyze the input parameters to obtain thickness convergence speed, overshoot and steady-state error value; S8: Parameter determination, adjusting the casting speed and scraper gap according to the thickness convergence speed, overshoot and steady-state error value; S9: stacking, continuing to print and coat a layer of film according to the preset circuit according to the parameters adjusted in step S8, and repeating in sequence until the terminal electrode is printed; S10: Covering with an upper protective film: Covering the top surface of the laminated inductor with an upper protective film; S11: Lamination: pack the laminated blocks in a laminating bag, vacuum seal them, and apply pressure by isostatic pressing to make the layers in the blocks more tightly bonded and tight; S12: cutting, cutting the laminated blocks into independent capacitor green sheets; S13: Debinding, placing the capacitor green body on the firing plate, and baking it at high temperature according to a preset temperature curve to remove the adhesive and organic matter in the chip; S14： The chips after sintering and debinding are subjected to high temperature treatment.

2. The dry-wet combined manufacturing process of a laminated chip inductor element according to claim 1, characterized in that: In step S10, when covering with the protective film, a dielectric layer is firstly cast on the lead-out terminal electrode by wet casting.

3. The dry-wet combined manufacturing process of a laminated chip inductor element according to claim 2, characterized in that: The thickness of the dielectric layer on the bottom surface of the upper protective film is determined according to the number of printings.

4. The dry-wet combined manufacturing process of a laminated chip inductor element according to claim 1, characterized in that: In step S5, the detection module detects the thickness and flatness of the membrane by using a laser rangefinder.

5. The dry-wet combined manufacturing process of a laminated chip inductor element according to claim 1, characterized in that: In step S7, the quality optimization system includes a feedforward control module that predicts the membrane thickness and flatness within a future predetermined time step and optimizes the control input to minimize the prediction error.

6. The dry-wet combined manufacturing process of a laminated chip inductor element according to claim 5, characterized in that: 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.

7. The dry-wet combined manufacturing process of a laminated chip inductor element according to claim 1 is characterized in that: The quality optimization system regularly generates historical records of film thickness, flatness, casting parameters and environmental conditions for subsequent analysis and quality control.

8. The dry-wet combined manufacturing process of a laminated chip inductor element according to claim 1 is characterized in that: In step S5, the casting machine also detects the ambient temperature and humidity.

9. The dry-wet combined manufacturing process of a laminated chip inductor element according to claim 1, characterized in that: In step S3, the position of the lower protective film is at the same position during each printing.

10. The dry-wet combined manufacturing process of a laminated chip inductor element according to claim 1, characterized in that: In step S1, the milled slurry is filtered.

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