How do vacuum coating and aging treatment shape the performance of DC High Voltage Pulse Discharge Energy Storage Film Capacitor? ​

Vacuum coating: Laying the foundation for metallized film performance​
The vacuum coating process is a key step in converting polypropylene light film into a conductive metallized film. When the polypropylene light film is fed into a vacuum coating machine with a very high vacuum degree, a precise material deposition process begins. ​
In this closed vacuum environment, the film release system is first started to allow the polypropylene light film to run smoothly along the established path. Subsequently, shielding oil is sprayed on the metal-free area planned on the surface of the light film. This step is like putting on a "protective suit" for specific areas of the light film to prevent metal vapor from depositing in these areas, thereby accurately dividing the metallized and non-metallized areas, laying the foundation for the reasonable layout of the subsequent capacitor electrodes. ​
After the shielding oil spraying is completed, the metal aluminum vapor and zinc vapor are sequentially "settled" in the specified area on the surface of the light film by physical vapor deposition. During the physical vapor deposition process, metal atoms obtain enough energy in a high vacuum environment, move in the form of gas phase and evenly adhere to the surface of the optical film, gradually forming an extremely thin metal film layer. ​
Precisely controlling the thickness, uniformity and deposition rate of the coating has become the key to ensuring the excellent performance of the metallized film. The coating thickness directly affects the conductivity of the metallized film and the withstand voltage of the capacitor. If the film layer is too thin, it may lead to insufficient conductivity and affect the charging and discharging efficiency of the capacitor; if the film layer is too thick, it will increase the weight and cost of the film, and may also affect the flexibility of the film, making it more prone to breakage during subsequent processing and use. ​
The uniformity of the coating is also crucial. Once the metal film layer is uneven, it will cause uneven distribution of the electric field on the surface of the film. Under the action of high voltage, local breakdown is prone to occur in the weak area, which in turn affects the service life and reliability of the entire capacitor. The control of the deposition rate is related to the balance between production efficiency and film quality. Too fast a deposition rate may cause the metal atoms to not have time to be evenly distributed, forming a rough film structure; too slow a deposition rate will reduce production efficiency and increase manufacturing costs.​
Through the precise control of these parameters, the metallized film formed has good conductivity and can quickly store and release charges. This metallized film can also play a self-healing property when the capacitor is partially broken down, quickly isolate the fault point, and ensure the normal operation of the capacitor. ​
Aging treatment: the key guarantee to improve the comprehensive performance of the film ​
After the vacuum coating is completed and the metallized polypropylene film roll with good vapor deposition is obtained, an indispensable process - aging treatment will follow. Aging treatment is to place the metallized polypropylene film roll in a specific temperature and humidity environment to allow it to undergo microstructural changes within a certain period of time. ​
In this process, the stress accumulated in the film during the vacuum coating, winding and other processes is gradually released. The existence of these stresses may cause the film to deform, warp and other problems during subsequent processing and use, seriously affecting the performance and assembly accuracy of the capacitor. Through aging treatment, the crystal structure inside the film becomes more stable. The stable crystal structure not only enhances the mechanical strength of the film, making it less likely to crack or break when subjected to external forces, but also improves the electrical performance of the film.​
From a microscopic perspective, during the aging process, the molecular chains inside the film will be rearranged and adjusted, and defects and impurities will be repaired and improved to a certain extent. This structural optimization further improves the insulation resistance of the film, makes the dielectric constant more stable, and can better adapt to different working environments and working conditions. ​
The film that has been aged shows better process adaptability in subsequent film cutting, winding, assembly and other processing links. In the film cutting process, due to the improved mechanical properties of the film, it can better withstand the cutting force of the tool and ensure the dimensional accuracy and edge quality of the film after slitting. During the winding operation, the flexibility and stability of the film make the winding process smoother, which can effectively avoid production interruptions and product quality defects caused by film deformation, breakage and other problems. ​
In addition, the effect of aging treatment on improving the overall reliability of capacitors is also particularly obvious in actual use. In harsh environments such as high temperature and high humidity, the film that has been aged can still maintain good performance and will not age or degrade rapidly due to environmental factors, thereby greatly extending the service life of the capacitor.​
In the manufacturing process of DC High Voltage Pulse Discharge Energy Storage Film Capacitor, the two seemingly independent processes of vacuum coating and aging treatment are actually closely related and complementary. Vacuum coating gives polypropylene film key properties such as conductivity and self-healing, providing a basis for the energy storage and discharge functions of the capacitor; aging treatment further optimizes the microstructure and comprehensive performance of the film, enhancing its stability and reliability under various working conditions. The two work together to ultimately shape a DC high voltage pulse discharge energy storage film capacitor with excellent performance, enabling it to play a key role in many fields such as power systems, industrial manufacturing, and new energy, providing a solid energy storage guarantee for the development of modern science and technology. With the continuous advancement of technology, these two processes will continue to be optimized to promote DC high voltage pulse discharge energy storage film capacitors to move towards higher performance and higher quality.