A method for improving lamination bubbles for MLCCs

Abstract

The application discloses a method for improving the lamination bubble of MLCC, comprising the following steps: mixing porcelain powder, organic solution, dispersing agent, adhesive and other auxiliary agents in a certain proportion to prepare porcelain slurry required for subsequent preparation; performing electrode printing after the casting operation of the porcelain slurry is completed; performing stacking after the film is peeled off, and forming a bubble discharge channel in the lamination process; performing uniform pressing on the film after the above operation is completed; and cutting each group of films to obtain the finished product; the method changes the morphology structure of the cast film by adjusting the ingredient process parameters and the formula, and forms the bubble discharge channel in the lamination process. Thus, the occurrence of the lamination bubble is inhibited, and in the packaging and uniform pressing process, the residual micro-bubbles can be effectively discharged from the bar block before the bar block is softened and pressed again, so that the layers of the bar block are fully pressed together, and the bar block delamination or cutting delamination caused by the local gas aggregation and residual is avoided.

Description

Technical Field

[0001] This invention relates to the field of MLCC fabrication technology, specifically to a method for improving the layered bubble structure of MLCCs. Background Technology

[0002] MLCC (Multi-layer Ceramic Capacitors) is an abbreviation for multilayer ceramic chip capacitors. It consists of ceramic dielectric films with printed electrodes (internal electrodes) stacked in a staggered manner, sintered at high temperature in a single process to form a ceramic chip, and then sealed with metal layers (external electrodes) at both ends of the chip, thus forming a monolithic structure, hence the name monolithic capacitor. During the manufacturing process, the stacking must achieve precise peeling and stacking of the cast films, ensuring internal consistency and uniformity; otherwise, the quality of subsequent processes will be affected. This is crucial for the successful production of MLCC preforms. Typically, during the stacking process, problems such as inclusions, environmental contamination, and bubbles can occur. In particular, residual bubbles can lead to severe delamination or cracking of the product after cutting and sintering, affecting product reliability. This invention focuses on solving the problem of bubbles in the stacking process. Traditional methods adjust the stacking temperature, pressure, and time, but due to fluctuations in the environment and incoming materials, the stacking bubbles repeatedly cause instability. The method of this invention focuses on addressing the problem at its source. By adjusting the characteristics of the membranes, it preserves the channels for gas to escape between the membranes, thereby fundamentally solving the problem of air bubbles. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of the prior art by providing a method for improving the stacked bubbles in MLCCs, thereby solving the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution, comprising the following steps:

[0005] Step 1: Mix ceramic powder, organic solvent, dispersant, binder and other additives in a certain proportion to prepare the ceramic slurry required for subsequent preparation;

[0006] Step 2: After completing the casting process of the ceramic slurry, perform electrode printing;

[0007] Step 3: After peeling off the membrane, high-precision stacking is performed to ensure internal consistency and uniformity, forming channels for air bubbles to escape during the stacking process.

[0008] Step 4: After completing the above operations, apply uniform pressure to the diaphragm;

[0009] Step 5: Cut each group of membranes to obtain the finished product.

[0010] As a preferred embodiment of the present invention, the ratio of the adhesive to the plasticizer is controlled as follows: (adhesive weight / ceramic powder weight)% / ceramic powder BET < 3% : 1, P / B < 40%.

[0011] As a preferred embodiment of the present invention, the ceramic slurry is injected by a liquid supply pump and fills the casting head. Then, the ceramic slurry is uniformly extruded from the casting head and cast onto a flat PET film through a smoothly rotating guide roller. The ceramic slurry is then dried and shaped on the PET film at high temperature, and the drying time is controlled within 20-45 minutes.

[0012] As a preferred embodiment of the present invention, the stacking process forms a channel for bubble discharge, so that the gas in the block has an effective discharge channel.

[0013] As a preferred embodiment of the present invention, during the uniform pressing process, microbubbles can be effectively expelled from the bar block before it softens and is pressed together.

[0014] As a preferred technical solution of the present invention, the shearing force of the grinding blades on the powder particles needs to be adjusted, and the speed is controlled at 15-30HZ.

[0015] Compared with the prior art, the present invention provides a method for improving the stacked bubbles of MLCCs, which has the following beneficial effects:

[0016] 1. This method for improving the lamination bubble structure of MLCCs involves adjusting the material process parameters and formulation to change the morphology and structure of the cast film, creating channels for bubble discharge during the lamination process. This suppresses the formation of bubbles in the lamination blocks and allows residual micro-bubbles to be effectively discharged from the blocks before softening and pressing during packaging and pressing. This ensures that the layers of the blocks are fully pressed together, preventing local gas accumulation and delamination or splitting caused by the blocks.

[0017] 2. This method for improving the bubble structure of MLCC stacks involves adjusting process parameters to control the shear force of the mill blades on the powder particles, so that the powder particles can be dispersed while reducing damage to individual powder particles. The speed is controlled below 30Hz, especially 25Hz, to reduce fine particles and create void channels on the diaphragm surface, forming certain exhaust channels to facilitate gas discharge.

[0018] 3. This method for improving bubble formation in MLCC lamination involves controlling the ratio of adhesive to plasticizer: (adhesive weight / ceramic powder weight)% / ceramic powder BET < 3% : 1, P / B < 40%. This ensures no adhesive agglomerates on the film surface, allowing the adhesive to fully coat the powder particles. A suitable plasticizing ratio results in a softening point temperature > 50℃. In the initial stages of lamination, packaging, and uniform pressing, this provides effective channels for gas to escape from the bulk material, thus reducing the risk of delamination and cracking caused by residual gas on the surface. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall process of the present invention;

[0020] Figure 2 This is a schematic diagram of the membrane with fine particles and a high plasticizing ratio of the present invention;

[0021] Figure 3 This is a schematic diagram of the membrane of the present invention, which has no fine particles and a low plasticization ratio;

[0022] Figure 4 This is a schematic diagram of the state before adjustment in this invention;

[0023] Figure 5 This is a schematic diagram of the adjusted state of the present invention. Detailed Implementation

[0024] 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.

[0025] Please see Figure 1-5 In this embodiment, the following steps are included:

[0026] Step 1: Mix ceramic powder, organic solvent, dispersant, binder and other additives in a certain proportion to prepare the ceramic slurry required for subsequent preparation;

[0027] Step 2: After completing the casting process of the ceramic slurry, perform electrode printing;

[0028] Step 3: After peeling off the membrane, high-precision stacking is performed to ensure internal consistency and uniformity, forming channels for air bubbles to escape during the stacking process.

[0029] Step 4: After completing the above operations, apply uniform pressure to the diaphragm;

[0030] Step 5: Cut each group of membranes to obtain the finished product.

[0031] It is important to note the following: control the ratio of adhesive to plasticizer, (adhesive weight / ceramic powder weight)% / ceramic powder BET < 3% : 1, P / B < 40%; the ceramic slurry is pumped in by the supply pump and fills the casting head, then the slurry is evenly extruded from the casting head and cast onto a flat PET film through a smoothly rotating guide roller. The slurry is then dried and shaped on the PET film at high temperature, with the drying time controlled between 20-45 minutes; during the lamination process, channels for air bubble discharge are formed, allowing gas in the block to have an effective outlet; during the uniform pressing process, micro-bubbles can be effectively discharged from the block again before it softens and is pressed; the shearing force of the grinding blades on the powder particles needs to be adjusted, and its speed is controlled between 15-30 Hz.

[0032] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for improving stacked bubble formation in MLCCs, characterized in that: Includes the following steps: Step 1: Mix ceramic powder, organic solvent, dispersant, binder and other additives in a certain proportion to prepare the ceramic slurry required for subsequent preparation; Step 2: After completing the casting process of the ceramic slurry, perform electrode printing; Step 3: After peeling off the membrane, high-precision stacking is performed to ensure internal consistency and uniformity, forming channels for air bubbles to escape during the stacking process. Step 4: After completing the above operations, apply uniform pressure to the diaphragm; Step 5: Cut each group of membranes to obtain the finished product; In step one, the ratio of adhesive to plasticizer is controlled as follows: (adhesive weight / ceramic powder weight) % / ceramic powder BET < 3% : 1, P / B < 40%. In step two, the extruder extrudes the ceramic slurry, allowing it to flow onto the surface of a smoothly rotating cooling roller. The slurry is cooled and set on the cooling roller for 30-45 minutes. In step three: the stacking process creates channels for bubble discharge, providing an effective outlet for the gas in the block. In step four: During the uniform pressing process, micro-air bubbles can be effectively expelled from the block again before it softens and is pressed together. In step five: the shearing force of the grinding blades on the powder particles needs to be adjusted, and the speed is controlled between 15-30 Hz.

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