Internal series metalized film, preparation method and filter capacitor

Abstract

The invention relates to an internal serial metallized film, a preparation method, a filter capacitor and a base film, the base film is made of a blending material of polyethylene glycol terephthalate and polyethylene naphthalate according to a mass ratio of 2: 3, and the thickness of the base film is 8-12 [mu] m; the multi-layer metallization layer is arranged on the base film and comprises a first metal layer, a buffer layer and a second metal layer, the buffer layer is located between the first metal layer and the second metal layer, the patterned structure forms a plurality of conductive units which are connected in series on the multi-layer metallization layer, each conductive unit is in a regular hexagon shape, and the first metal layer is arranged on the first metal layer. The side length of the conductive units is 3-6mm, and an isolation belt with the width of 0.3-0.8 mm is arranged between the adjacent conductive units. According to the invention, a plurality of key performance indexes such as high-frequency filtering performance, voltage endurance capability, oxidation resistance, structural stability, light transmission and the like are optimized and improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic components, and particularly to an internally connected metallized film, a preparation method, and a filter capacitor. Background Art

[0002] In the current era of rapid development of electronic technology, the functions of electronic devices are constantly enriched and their performance is continuously improved, which puts more stringent requirements on each internal electronic component, especially filter capacitors. As a key component to ensure the stable operation of electronic circuits and optimize signal quality, the performance of filter capacitors directly affects the working efficiency and reliability of the entire electronic device.

[0003] Traditional metallized films used in filter capacitors often expose many problems. For example, the conductivity of traditional metallized films is limited, and the equivalent series resistance (ESR) is relatively high in high-frequency working environments, resulting in poor filtering effects and difficulty in meeting the requirements for precise filtering of high-frequency signals in modern electronic circuits.

[0004] In addition, in complex and variable environmental conditions, such as high temperature, high humidity, and environments with oxidizing or corrosive gases, the metal layer is prone to oxidation and corrosion, and water vapor intrusion causes deterioration of the film performance, thereby affecting the service life and stability of the capacitor. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides an internally connected metallized film, a preparation method, and a filter capacitor. The specific technical solutions are as follows:

[0006] One object of the present invention is to provide an internally connected metallized film: including a base film, the base film is made of a blend material of polyethylene terephthalate and polyethylene naphthalate in a mass ratio of 2:3, and the thickness of the base film is 8 - 12 μm;

[0007] A multi-layer metallized layer, disposed on the base film, including a first metal layer, a buffer layer, and a second metal layer. The buffer layer is located between the first metal layer and the second metal layer. The first metal layer is a copper layer with a thickness between 100 - 150 nm. The buffer layer is disposed on the side of the first metal layer away from the base film. The buffer layer is a nickel-chromium alloy layer, in which the atomic proportion of chromium is limited within the range of 20% - 25%, and the thickness is 20 - 40 nm. The second metal layer is a silver-palladium alloy layer, and the proportion of palladium in the total mass of the alloy is between 3% - 6%, and the thickness is 180 - 220 nm;

[0008] A patterned structure, the patterned structure forms a plurality of mutually connected conductive units on the multi-layer metallized layer. Each conductive unit is a regular hexagon, and its side length is set between 3 - 6 mm. A isolation band with a width of 0.3 - 0.8 mm is provided between adjacent conductive units.

[0009] Preferably, the multi-layer metallization layer further includes a barrier layer, a transition layer, an antioxidant enhancement layer, and an antireflective conductive layer, and the patterned structure is formed on the entire multi-layer metallization layer composed of the barrier layer, the first metal layer, the buffer layer, the transition layer, the second metal layer, the antioxidant enhancement layer, and the antireflective conductive layer.

[0010] The second object of the present invention is to provide an internal series metallized film, comprising the following steps:

[0011] Base film preparation: Weigh the raw materials of polyethylene terephthalate and polyethylene naphthalate glycolate accurately according to the mass ratio of 2:3, and put them into the hopper of a twin-screw extruder to make a base film with a thickness of 8 - 12 μm;

[0012] Barrier layer deposition preparation: Place the prepared base film in the reaction chamber of a low-pressure chemical vapor deposition device. According to the parameters of silane flow rate of 10 - 20 sccm, ammonia flow rate of 30 - 50 sccm, reaction pressure of 100 - 200 Pa, and reaction temperature of 700 - 800 °C, introduce the corresponding reaction gases, so that silane and ammonia chemically react on the surface of the base film, and the deposited barrier layer thickness reaches 50 - 100 nm;

[0013] First metal layer preparation: Transfer the base film deposited with the barrier layer smoothly to the reaction chamber of a plasma-enhanced chemical vapor deposition device. First, evacuate the chamber to below 5×10 -4 Pa. According to the parameter requirements of argon flow rate of 30 - 40 sccm, hydrogen flow rate of 10 - 20 sccm, gas flow rate of 40 - 60 sccm, reaction temperature of 300 - 350 °C, and deposition duration of 15 - 20 minutes, and at the same time use a power monitoring device to control the power density of the plasma within the range of 0.5 - 1.5 W / cm 2 range, and perform plasma-enhanced chemical vapor deposition to deposit a copper layer on the surface of the barrier layer;

[0014] Buffer layer deposition preparation: Use the atomic layer deposition process. According to the nickel-chromium alloy composition and the deposition rate requirement of 0.3 - 0.6 nm / cycle, and according to the characteristics of the selected atomic layer deposition device, deposit a buffer layer on the surface of the existing metal layer to make the buffer layer thickness reach 20 - 40 nm;

[0015] Transition layer deposition step: Transfer the film deposited with the buffer layer to the reaction chamber of a magnetron sputtering device. First, evacuate to below 5×10 -4 Pa. Introduce argon as the sputtering gas, install an alloy material composed of titanium and tantalum with a titanium atom ratio of 70% - 80% as the target, adjust the sputtering power to 80 - 120 W, and start depositing the transition layer. During the deposition process, make the transition layer thickness reach 10 - 20 nm;

[0016] Second metal layer deposition step: Adjust the parameters of the magnetron sputtering equipment, replace it with a silver-palladium alloy source gas, maintain the working gas pressure in the range of 0.1 - 0.5 Pa, deposit the second metal layer on the surface of the transition layer, and make the thickness reach 180 - 220 nm through deposition;

[0017] Patterning structure formation: Carefully place the film coated with the above multi-layer structure on the workbench of the electron beam lithography equipment. According to the preset regular hexagon shape of the conductive unit and the pattern parameters of the isolation strip width, write the lithography program and input it into the electron beam lithography equipment. Use the high-energy electron beam generated by the electron beam lithography equipment to expose the film according to the scanning path set by the program. Subsequently, through the chemical treatment steps of development and etching, remove the metallization layer in the isolation strip area to form a pattern of conductive units connected in series, and obtain the finished product of the internal series metallized film.

[0018] The third object of the present invention is to provide a filter capacitor, which includes the filter capacitor manufactured by using the above internal series metallized film.

[0019] Advantages of the present invention:

[0020] 1. Through the internal series metallized film structure and preparation process of the present application, especially the reasonable selection and deposition of each metal layer and the construction of the patterned conductive units, the filter capacitor manufactured based on this film shows excellent filtering effects in high-frequency environments. Compared with traditional filter capacitors, it can filter out high-frequency clutter signals more efficiently, effectively improving the purity and stability of signals in electronic circuits.

[0021] 2. During the manufacturing process of the filter capacitor, from the high-quality preparation of the internal series metallized film to the overall packaging link of the capacitor, each step collaboratively ensures the voltage withstand capacity of the product. The barrier layer in the internal series metallized film can effectively block the diffusion of small molecule substances such as water vapor and oxygen to the metallization layer and the migration of metal atoms into the base film, avoiding the influence of factors such as internal structure erosion on the voltage withstand performance, being able to work stably in a high-voltage environment, ensuring the safety of circuit operation, broadening its application scenario range, and being applicable to various electronic devices with different voltage levels.

[0022] 3. The antioxidant enhancement layer of the internal series metallized film adopts an innovative structure composed of graphene and inorganic ceramic particles. Graphene is precisely prepared by chemical vapor deposition, and ceramic particles are evenly adsorbed on its surface and then adhered to the metal layer, significantly delaying the oxidation process of the metal layer during use, effectively extending the service life of the product, and reducing the maintenance cost and replacement frequency.

[0023] 4. In the thin film preparation process, buffer layers and transition layers are provided between each metal layer. The buffer layer can enhance the bonding tightness between adjacent metal layers, avoid phenomena such as delamination and peeling under the action of temperature changes, mechanical stress, etc., and ensure the reliability and stability of its electrical performance.

[0024] 5. Considering the beneficial effects in all aspects mentioned above, the internal series metallized thin film and filter capacitor involved in this patent have achieved optimization and improvement in multiple key performance indicators such as high-frequency filtering performance, voltage withstand capacity, antioxidant property, structural stability, and light transmittance. It is not an improvement in a single performance, but a collaborative optimization of the overall performance. This enables it to well adapt to the development trends of modern electronic circuits towards diversification, complexity, and high performance, meet the various strict requirements for filter capacitors in different industries and application scenarios, and provide strong technical support for promoting the performance improvement and function expansion of related electronic devices. Detailed implementation manners

[0025] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] Embodiment

[0027] The internal series metallized thin film, preparation method and filter capacitor. The internal series metallized thin film provided by the present invention has a multi-layer composite structure, and each layer closely cooperates and acts synergistically to improve the overall performance of the thin film from multiple aspects. Its detailed structure is as follows:

[0028] Base film: The base film is prepared from a blend material of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) with a mass ratio of 2:3. PET has good flexibility and is easy to process and form, while PEN exhibits excellent high-temperature resistance, high barrier property (significant barrier effect on small molecules such as water vapor and oxygen), and high electrical insulation. The combination of the two endows the base film with multiple excellent characteristics and enables it to maintain stable performance under different working conditions.

[0029] The preparation of the base film is achieved by the melt blending method. The specific steps are as follows: First, weigh the PET and PEN raw materials in proportion and put them into a twin-screw extruder. The temperatures of each heating zone are set at 260 °C, 265 °C, 270 °C, 275 °C, and 280 °C in sequence, and the screw speed is controlled at 100 - 120 rpm to fully melt and blend the raw materials in the barrel. After forming a uniform melt, it is extruded through a die head to form a thick sheet with a thickness of 2 - 3 mm. Then, the thick sheet is placed on a cooling roller and quickly cooled to room temperature to avoid excessive crystallinity affecting the subsequent stretching performance. Subsequently, the cooled thick sheet is sent into a stretching machine, first stretched longitudinally at a stretching ratio of 3 - 5 times at 160 - 180 °C, and then stretched transversely at a stretching ratio of 3 - 5 times at 180 - 200 °C. Finally, the thickness of the base film reaches 8 - 12 μm to ensure that the base film obtains an ideal molecular orientation and crystallinity, thereby enhancing its mechanical strength and dielectric properties.

[0030] Barrier layer: The barrier layer is made of silicon nitride (Si3N4) material. Due to its excellent chemical stability, high hardness, and good insulation performance, it can effectively prevent small molecules such as water vapor and oxygen in the external environment from penetrating into the metallization layer, and at the same time avoid the reverse diffusion of metal atoms into the base film interior, providing a reliable protection barrier for the base film and the subsequent metallization layer and maintaining the stability of the performance of each layer.

[0031] The barrier layer is prepared by the low-pressure chemical vapor deposition (LPCVD) process. The specific process is as follows: Place the prepared base film in the reaction chamber, introduce silane (SiH4) and ammonia (NH3) as reaction gases. The flow rate of silane is controlled at 10 - 20 sccm, the flow rate of ammonia is controlled at 30 - 50 sccm, maintain the pressure in the reaction chamber at 100 - 200 Pa, and at the same time adjust the reaction temperature to 700 - 800 °C. Under such conditions, silane and ammonia chemically react on the surface of the base film to generate silicon nitride and deposit to form the barrier layer. By precisely controlling the deposition time at 30 - 60 minutes, the thickness of the barrier layer reaches 50 - 100 nm to ensure that it has a good barrier effect and will not have an adverse impact on the overall film performance.

[0032] First metal layer:

[0033] Copper with a purity as high as 99.99% is selected as the raw material, and a copper layer is deposited on the surface of the barrier layer by means of plasma-enhanced chemical vapor deposition (PECVD) process. Copper has excellent electrical conductivity, which can effectively reduce the conductive resistance of the film, laying a good foundation for the conductive path of the entire metallized film. At the same time, a relatively stable bonding interface can be formed between copper and the barrier layer and the subsequent layers, ensuring the integrity of the structure.

[0034] During the deposition process, after evacuating the reaction chamber to an appropriate degree, argon and hydrogen are introduced as reaction gases (argon flow rate 30 - 40 sccm, hydrogen flow rate 10 - 20 sccm), a copper source gas with a purity of 99.99% is introduced, the reaction temperature is adjusted to 300 - 350 °C, the gas flow rate is controlled at 40 - 60 sccm, and deposition is continued for 15 - 20 minutes to maintain the copper layer thickness at 100 - 150 nm, so as to ensure that the copper layer can not only provide good electrical conductivity but also maintain structural stability during subsequent processes and use.

[0035] Buffer layer: The buffer layer is made of nickel-chromium alloy, and the atomic proportion of chromium is set at 20% - 25%. Nickel-chromium alloy has good high-temperature resistance, chemical stability, and moderate hardness, and plays a key buffering role in the multi-layer metallization structure. It can not only enhance the bonding tightness between the first metal layer and the subsequent transition layer, avoid phenomena such as delamination and peeling between different metal layers by forming chemical bonding or diffusion bonding at the interface, but also effectively relieve the thermal stress caused by the temperature change during the charge and discharge of the filter capacitor, and ensure the stability of the overall structure of the metallized film under thermal shock.

[0036] The buffer layer is deposited by atomic layer deposition (ALD) process. By precisely controlling the deposition rate at 0.3 - 0.6 nm / cycle, nickel-chromium alloy is deposited on the surface of the already deposited copper layer, and the deposition thickness is controlled at 20 - 40 nm. Strictly control the deposition parameters to ensure that the thickness of the buffer layer is uniform and dense, so as to achieve the best buffering and bonding effects while avoiding excessive interference with the overall electrical conductivity.

[0037] Transition layer: The transition layer uses an alloy material composed of titanium (Ti) and tantalum (Ta), and the atomic proportion of titanium is 70% - 80%. Titanium-tantalum alloy has moderate hardness, excellent chemical stability, and good interface compatibility with adjacent metal layers (nickel-chromium alloy and subsequent silver-palladium alloy), which can make the stress transfer between different metal layers more uniform, further strengthen the bonding strength between the metallization layers, and effectively prevent excessive internal stress caused by the difference in thermal expansion coefficients of each metal layer during temperature change, thus ensuring the integrity and stability of the entire metallized film structure under complex working conditions.

[0038] The magnetron sputtering process is used for the deposition of the transition layer. During operation, first evacuate the reaction chamber to below 5×10 -4 Pa, then introduce argon as the sputtering gas (argon flow rate 20 - 30 sccm), use titanium-tantalum alloy as the target, and deposit the transition layer on the surface of the buffer layer by adjusting the sputtering power at 80 - 120 W. By controlling the deposition time at 10 - 15 minutes, the thickness of the transition layer reaches 10 - 20 nm, ensuring that it can fully play the role of stress buffering and enhancing bonding.

[0039] Second Metal Layer: The second metal layer is made of silver-palladium alloy, and the content of palladium accounts for 3%-6% of the total mass of the alloy. Silver itself has excellent electrical conductivity. After adding an appropriate amount of palladium element to form an alloy, it can not only maintain good electrical conductivity to a certain extent, but also significantly improve the antioxidant and anti-sulfuration properties of the metallized film. In the actual application environment, this alloy layer can effectively resist the erosion of oxygen, sulfur-containing compounds, etc. in the air on the metal layer, ensuring the stability of the electrical conductivity of the capacitor during long-term use, and is especially suitable for various application scenarios with relatively harsh environmental conditions.

[0040] Deposit the silver-palladium alloy layer by magnetron sputtering process. After evacuating the reaction chamber to the corresponding requirements, replace it with the silver-palladium alloy source gas (the palladium content is configured proportionally), adjust the sputtering power to 120-180W, and deposit the silver-palladium alloy layer on the surface of the transition layer with a thickness of 180-220nm to form a stable and excellent outer conductive structure.

[0041] Antioxidant Enhancement Layer:

[0042] The antioxidant enhancement layer is mainly composed of graphene and inorganic ceramic particles (such as alumina, Al2O3). Graphene has excellent electrical conductivity and chemical stability. On the one hand, it can play a certain role in improving the overall electrical conductivity. On the other hand, its two-dimensional sheet structure can physically shield the underlying metal layer and block the contact with oxidizing substances such as oxygen. The alumina ceramic particles uniformly dispersed between the graphene sheets, with their high melting point, high strength and good antioxidant properties, further enhance the antioxidant and abrasion resistance of this layer. The two work together to provide strong antioxidant protection for the metallized film, significantly delaying the oxidation process of the metal layer and ensuring its performance stability during long-term use.

[0043] The preparation process is as follows: First, grow high-quality graphene on a copper foil substrate by chemical vapor deposition (CVD) method. Then, use methods such as ultrasonic dispersion to uniformly disperse nano-scale alumina ceramic particles (with a particle size between 50-200nm) in an organic solvent (such as N-methylpyrrolidone, NMP) to form a ceramic particle dispersion liquid. Next, immerse the copper foil with grown graphene in the dispersion liquid to make the ceramic particles fully adsorbed on the surface of the graphene. After that, transfer the graphene composite layer with ceramic particles to the surface of the second metal layer through a transfer process, and finally make it closely adhere through hot pressing and other methods to form an antioxidant enhancement layer with a thickness controlled at 20-50nm.

[0044] Anti-reflection conductive layer: The anti-reflection conductive layer is made of indium tin oxide (ITO) in the transparent conductive oxide (TCO) material, which is composed of 90% indium oxide (In2O3) and 10% tin oxide (SnO2) (by mass). ITO material has good conductivity, can form an effective conductive path with the underlying metallization layer to ensure smooth charge transfer, and has a high light transmittance in the visible light band. This enables the film not to cause obvious obstruction to light transmission when applied to some special scenarios with requirements for light transmittance (such as the filter circuit in optoelectronic device integration), thus meeting the requirements for both optical and electrical properties in special application scenarios and expanding the application range of the inner-string metallized film.

[0045] The magnetron sputtering process in physical vapor deposition (PVD) is used to prepare the anti-reflection conductive layer. Place the target containing indium and tin on the target seat of the sputtering equipment. After pumping the vacuum below 1×10-3 Pa, introduce argon and oxygen as sputtering gases (argon flow rate 40 - 60 sccm, oxygen flow rate 1 - 2 sccm), adjust the sputtering power to 150 - 200 W, deposit the ITO film on the surface of the antioxidant-enhanced layer, and by controlling the deposition time for 20 - 30 minutes, make the thickness of the anti-reflection conductive layer reach 80 - 120 nm to achieve a good balance between light transmittance and conductivity.

[0046] Patterned structure:

[0047] On the film that has completed the above multi-layer structure plating, use electron beam lithography technology to create a pattern of interconnected conductive units. Each conductive unit is designed in the shape of a regular hexagon with a side length of 3 - 6 mm. Based on its good geometric symmetry, this shape can make the conductive units closely and evenly arranged on the film surface, ensuring a relatively uniform electric field distribution between each unit and avoiding adverse effects on the filtering performance caused by abnormal local electric fields. A isolation band with a width of 0.3 - 0.8 mm is reserved between adjacent conductive units. Through precise electron beam exposure, development, etching and other steps, remove the metallization layer in the isolation band area to enable electrical inner-string connection between each conductive unit. Through this unique inner-string structure, the equivalent series model of the capacitor can be optimized, effectively reducing the equivalent series resistance (ESR) and improving the electrical performance of the film in a high-frequency environment, making it show a more excellent filtering effect in the application of filter capacitors.

[0048] Preparation method:

[0049] The preparation method of the inner-string metallized film of the present invention includes multiple steps, and each step is closely connected to orderly prepare the respective layer structures of the above-mentioned inner-string metallized film, specifically as follows:

[0050] Base film preparation step:

[0051] Accurately weigh the raw materials according to the requirement that the mass ratio of polyethylene terephthalate (PET) to polyethylene naphthalate (PEN) is 2:3, and put them into the hopper of the twin-screw extruder. Set the temperatures of each heating zone of the twin-screw extruder to be 260 °C, 265 °C, 270 °C, 275 °C, and 280 °C in sequence, control the screw speed at 100 - 120 rpm, and make the raw materials fully melt and blend in the barrel. After forming a uniform melt, extrude a thick sheet with a thickness of 2 - 3 mm through the die head.

[0052] Place the thick sheet on the cooling roller and quickly cool it to room temperature. Then, send the cooled thick sheet into the stretching machine. First, stretch it longitudinally at a stretching ratio of 3 - 5 times at 160 - 180 °C, and then stretch it transversely at a stretching ratio of 3 - 5 times at 180 - 200 °C. Finally, obtain a base film with a thickness of 8 - 12 μm.

[0053] Barrier layer deposition step:

[0054] Place the prepared base film in the reaction chamber of a low-pressure chemical vapor deposition (LPCVD) device, introduce silane (SiH4) and ammonia (NH3) as reaction gases. Control the silane flow rate at 10 - 20 sccm and the ammonia flow rate at 30 - 50 sccm. Adjust the pressure in the reaction chamber to 100 - 200 Pa, and at the same time raise the reaction temperature to 700 - 800 °C, so that silane and ammonia chemically react on the surface of the base film to form silicon nitride and deposit to form a barrier layer. By precisely controlling the deposition time at 30 - 60 minutes, ensure that the thickness of the barrier layer reaches 50 - 100 nm.

[0055] First metal layer deposition step:

[0056] Transfer the base film deposited with the barrier layer to the reaction chamber of a plasma-enhanced chemical vapor deposition (PECVD) device. First, evacuate the chamber to an appropriate degree (generally evacuate to below 5×10 -4 Pa), then introduce argon and hydrogen as reaction gases (argon flow rate 30 - 40 sccm, hydrogen flow rate 10 - 20 sccm), introduce a copper source gas with a purity of 99.99%, adjust the reaction temperature to 300 - 350 °C, control the gas flow rate at 40 - 60 sccm, and perform plasma-enhanced chemical vapor deposition. Control the deposition duration at 15 - 20 minutes to make the thickness of the copper layer reach 100 - 150 nm.

[0057] Buffer layer deposition step:

[0058] Maintain the stability of the chamber environment of the corresponding equipment (such as temperature, vacuum degree, etc.). Using the atomic layer deposition (ALD) process, with nickel-chromium alloy (chromium atom proportion 20%-25%) as the raw material, deposit a buffer layer on the surface of the existing copper layer by precisely controlling the deposition rate at 0.3-0.6 nm / cycle, and control the deposition thickness within 20-40 nm.

[0059] Transition layer deposition step:

[0060] Transfer the film deposited with the buffer layer to the reaction chamber of the magnetron sputtering equipment. First, evacuate to below 5×10 -4 Pa, then introduce argon as the sputtering gas (argon flow rate 20-30 sccm). Using titanium-tantalum alloy (titanium atom proportion 70%-80%) as the target, adjust the sputtering power to 80-120 W, deposit a transition layer on the surface of the buffer layer, control the deposition time within 10-15 minutes, and make the thickness of the transition layer reach 10-20 nm.

[0061] Second metal layer deposition step:

[0062] Adjust the parameters of the magnetron sputtering equipment again, replace it with a silver-palladium alloy source gas (palladium content accounts for 3%-6% of the total mass of the alloy), adjust the sputtering power to 120-180 W, deposit a second metal layer on the surface of the transition layer, and make the thickness of this layer reach 180-220 nm.

[0063] Antioxidant enhancement layer preparation and deposition step:

[0064] First, grow high-quality graphene on the copper foil substrate by chemical vapor deposition (CVD). Then, use ultrasonic dispersion technology to uniformly disperse alumina ceramic particles with a particle size between 50-200 nm in the organic solvent N-methylpyrrolidone (NMP) to form a ceramic particle dispersion liquid.

[0065] Immerse the copper foil grown with graphene in the dispersion liquid to allow the ceramic particles to be fully adsorbed on the surface of the graphene. Then, transfer the graphene composite layer with ceramic particles to the surface of the already deposited second metal layer through a transfer process, and finally use hot pressing or other methods to make it closely adhere to form an antioxidant enhancement layer with a thickness of 20-50 nm.

[0066] Anti-reflection conductive layer deposition step:

[0067] Place the film with an antioxidant-enhanced layer in the reaction chamber of a magnetron sputtering device in physical vapor deposition (PVD). Place the target containing indium and tin on the target holder. First, evacuate to below 1×10-3 Pa, and then introduce argon and oxygen as sputtering gases (argon flow rate 40 - 60 sccm, oxygen flow rate 1 - 2 sccm). Adjust the sputtering power to 150 - 200 W, and deposit an indium tin oxide (ITO) film on the surface of the antioxidant-enhanced layer. By controlling the deposition time at 20 - 30 minutes, the thickness of the antireflection conductive layer reaches 80 - 120 nm.

[0068] Patterning structure formation step:

[0069] Carefully place the film coated with the above multi-layer structure on the workbench of an electron beam lithography device. According to the preset pattern parameters such as the regular hexagon shape of the conductive unit (side length 3 - 6 mm) and the isolation strip width (0.3 - 0.8 mm), write the lithography program. Use the high-energy electron beam generated by the electron beam lithography device to expose the film according to the scanning path set by the program. Subsequently, through chemical treatment steps such as development and etching, precisely remove the metallization layer in the isolation strip area, thus successfully forming a pattern of conductive units in series and obtaining a finished product of an internally series-connected metallized film.

[0070] Filter capacitor:

[0071] Manufacture a filter capacitor based on the above high-performance internally series-connected metallized film. Its specific structure and manufacturing process are detailed as follows:

[0072] Capacitor core winding:

[0073] Select three pieces of the internally series-connected metallized film prepared above and stack them in a "sandwich" structure, that is, the metallization layers of the two films face outward, and a polytetrafluoroethylene film with a thickness of 1.5 - 2.5 μm is sandwiched as the dielectric layer in the middle. Then, use a precision winding machine to wind without induction with a constant tension. The number of winding turns is determined according to the required capacitance value, usually in the range of 12 - 18 turns. During the winding process, the winding tension is monitored and adjusted in real time through a tension sensor to ensure the tightness and flatness of the winding, and to prevent problems such as wrinkles and gaps from affecting the performance of the capacitor.

[0074] Electrode lead-out and connection:

[0075] After winding, use laser welding technology to lead out the electrodes at both ends of the core. The electrodes are made of gold foil. Through precise control of the laser energy, the gold foil is reliably connected to the ends of the conductive units of the internally series-connected metallized film to ensure good electrical conductivity. Then, carefully bend and fix the part where the electrodes are led out for convenient and stable connection with external pins later.

[0076] Encapsulation and potting:

[0077] Place the core with electrodes into a housing made of ceramic material. The housing is designed in the shape of a cylinder, and its inner diameter and height are precisely adapted according to the size of the core. Inject a high-performance silicone rubber potting compound into the housing, and the filling rate of the potting compound is maintained at 92%-98%, ensuring that the core can be completely and tightly wrapped by the potting compound. This can not only provide excellent insulation performance but also contribute to heat dissipation, improving the stability of the capacitor during actual operation.

[0078] Pin installation and finished product assembly:

[0079] After the potting compound is fully cured, install metal pins at both ends of the housing. The pins are made of kovar alloy, and the pins are firmly connected to the previously led-out and fixed electrodes by high-temperature brazing to complete the final assembly of the filter capacitor.

[0080] The filter capacitor manufactured through the above structure and process can reduce the equivalent series resistance (ESR) to below 6 mΩ in the high-frequency band of 200 kHz - 2 MHz, the withstand voltage capacity reaches above 650 V, has excellent self-healing performance, and the filtering efficiency for high-frequency clutter signals is increased by more than 40% compared with traditional filter capacitors, and can well meet the strict requirements of modern various complex electronic circuits for high-performance filter capacitors.

[0081] The following is the part to continue to supplement and improve the above patent content, further enriching the specific embodiments and elaborating the claims in more detail to make the entire patent document more complete and comprehensive:

[0082] Example 1

[0083] Preparation of inner series metallized film:

[0084] Base film preparation: Precisely weigh 12 g of polyethylene terephthalate (PET) and 18 g of polyethylene naphthalate (PEN), and put them into a twin-screw extruder. Carry out melt blending according to the set temperature range (the temperatures of each heating zone are 260 °C, 265 °C, 270 °C, 275 °C, 280 °C in sequence) and screw speed (100 rpm) to extrude a thick sheet with a thickness of 2.5 mm. After cooling, first longitudinally stretch it 4 times at 170 °C on a stretching machine, and then transversely stretch it 4 times at 190 °C to obtain a base film with a thickness of 10 μm.

[0085] Barrier layer deposition: Place the base film in a low-pressure chemical vapor deposition (LPCVD) device, introduce silane (flow rate 15 sccm) and ammonia (flow rate 40 sccm), maintain the pressure at 150 Pa, react at 750 °C to generate a silicon nitride barrier layer, and the deposition time is 45 minutes, and the thickness of the barrier layer reaches 75 nm.

[0086] Deposition of the first metal layer: In a plasma-enhanced chemical vapor deposition (PECVD) equipment, a copper layer is deposited on a base film with a barrier layer (gas flow rate 50 sccm, reaction temperature 320 °C, deposition time 18 minutes, thickness 120 nm).

[0087] Deposition of the buffer layer: A nickel-chromium alloy buffer layer is deposited using the atomic layer deposition (ALD) process (chromium atom ratio 22%, deposition rate 0.5 nm / cycle, deposition thickness 30 nm).

[0088] Deposition of the transition layer: Using the magnetron sputtering process, with a titanium-tantalum alloy (titanium atom ratio 75%) as the target, a transition layer is deposited on the buffer layer (argon gas flow rate 25 sccm, sputtering power 100 W, deposition time 12 minutes, thickness 15 nm).

[0089] Deposition of the second metal layer: A silver-palladium alloy second metal layer is deposited through the magnetron sputtering process (palladium content accounts for 4% of the total mass of the alloy, sputtering power 150 W, thickness 200 nm).

[0090] Preparation and deposition of the antioxidant enhancement layer: First, grow graphene on a copper foil substrate, then disperse alumina ceramic particles with a particle size of 100 nm in N-methylpyrrolidone (NMP) to make a dispersion liquid. After the graphene adsorbs the ceramic particles, transfer them to the surface of the second metal layer and thermally press and bond them to form an antioxidant enhancement layer with a thickness of 30 nm.

[0091] Deposition of the antireflective conductive layer: Use the magnetron sputtering process to deposit an indium tin oxide (ITO) thin film on the antioxidant enhancement layer (argon gas flow rate 50 sccm, oxygen gas flow rate 1.5 sccm, sputtering power 180 W, deposition time 25 minutes, thickness 100 nm).

[0092] Formation of the patterned structure: Use an electron beam lithography equipment (according to the parameters of the side length of the regular hexagon of the conductive unit being 4 mm and the isolation bandwidth being 0.5 mm) for lithography operations. After processes such as exposure, development, and etching, an inner-string metallized thin film is made.

[0093] Manufacture and testing of the filter capacitor:

[0094] According to the above filter capacitor manufacturing process, take three inner-string metallized thin films and sandwich a polytetrafluoroethylene film dielectric layer (thickness 2 μm) and wind them non-inductively for 15 turns. The lead electrodes are laser welded with gold foil. After being installed in a cylindrical ceramic shell, pour silicone rubber potting glue (filling rate 95%), and install kovar alloy pins after curing to make a filter capacitor.

[0095] Perform performance tests on this filter capacitor. At a frequency of 800 kHz, the measured ESR is 4 mΩ, the withstand voltage reaches 680 V, and use a vector network analyzer to test the filtering efficiency of high-frequency clutter signals, which is about 45% higher than that of traditional capacitors of the same specification.

[0096] Example 2

[0097] Preparation of Inner-Strung Metallized Film

[0098] Base Film Preparation:

[0099] Weigh 10 g of polyethylene terephthalate (PET) and 15 g of polyethylene naphthalate (PEN), and put them into a twin-screw extruder. The temperatures of each heating zone are set to 262 °C, 268 °C, 272 °C, 278 °C, and 280 °C in sequence. The screw speed is controlled at 110 rpm. The thickness of the extruded thick sheet is 2.2 mm. After cooling, it is longitudinally stretched 3.5 times at 160 °C on a stretching machine first, and then transversely stretched 4.5 times at 190 °C to obtain a base film with a thickness of 9 μm.

[0100] Barrier Layer Deposition:

[0101] Put the base film into the reaction chamber of a low-pressure chemical vapor deposition (LPCVD) device, introduce silane (flow rate 12 sccm) and ammonia (flow rate 35 sccm), maintain the pressure at 120 Pa, react at 720 °C, and the deposition time is 35 minutes to make the thickness of the barrier layer reach 60 nm.

[0102] First Metal Layer Deposition:

[0103] In a plasma-enhanced chemical vapor deposition (PECVD) device, deposit a copper layer on the base film with a barrier layer. After evacuating to an appropriate degree, introduce argon (flow rate 32 sccm) and hydrogen (flow rate 12 sccm), introduce a copper source gas, deposit at 330 °C for 16 minutes, and the thickness of the copper layer reaches 110 nm.

[0104] Buffer Layer Deposition:

[0105] Using the atomic layer deposition (ALD) process, with nickel-chromium alloy (chromium atom proportion 20%) as the raw material, set the deposition rate to 0.4 nm / cycle, deposit a buffer layer on the surface of the copper layer, and the deposition thickness reaches 25 nm.

[0106] Transition Layer Deposition:

[0107] Adopt the magnetron sputtering process, use titanium-tantalum alloy (titanium atom proportion 72%) as the target, introduce argon (flow rate 22 sccm), adjust the sputtering power to 90 W, deposit a transition layer on the buffer layer, the deposition time is 11 minutes, and the thickness reaches 12 nm.

[0108] Second Metal Layer Deposition:

[0109] Deposit a silver-palladium alloy second metal layer through the magnetron sputtering process. The palladium content accounts for 3% of the total mass of the alloy, the sputtering power is 130 W, and the deposition thickness reaches 190 nm.

[0110] Preparation and Deposition of Antioxidant Enhancement Layer:

[0111] First, grow high-quality graphene on a copper foil substrate by chemical vapor deposition (CVD). Then, disperse alumina ceramic particles with a particle size of 80 nm in N-methylpyrrolidone (NMP) to form a dispersion. Let the graphene adsorb the ceramic particles and then transfer them to the surface of the second metal layer. After hot pressing and laminating, an antioxidant enhancement layer with a thickness of 25 nm is formed.

[0112] Deposition of Antireflective Conductive Layer:

[0113] Deposit indium tin oxide (ITO) thin film on the antioxidant enhancement layer by magnetron sputtering process. The argon flow rate is 45 sccm, the oxygen flow rate is 1.2 sccm, the sputtering power is 160 W, and the deposition time is 22 minutes to make the thickness reach 90 nm.

[0114] Formation of Patterned Structure:

[0115] On an electron beam lithography equipment, perform lithography operations according to the parameters of the side length of the regular hexagon of the conductive unit being 3.5 mm and the isolation bandwidth being 0.4 mm to complete the patterning of the inner series metallized film.

[0116] Manufacture and Test of Filter Capacitor

[0117] Take three pieces of the made inner series metallized film, sandwich a polytetrafluoroethylene film with a thickness of 1.8 μm in the middle, and use a precision winding machine to wind it non-inductively for 14 turns with a constant tension.

[0118] Lead out the electrodes by laser welding gold foil. After bending and fixing the electrodes, install them into a ceramic shell (inner diameter 9 mm, height 18 mm), and pour silicone rubber potting adhesive with a filling rate of 93%.

[0119] After curing, install kovar alloy pins to assemble into a filter capacitor. Through performance testing, it is found that at a frequency of 1 MHz, the ESR is 5 mΩ, the withstand voltage reaches 660 V, and the filtering efficiency for high-frequency clutter signals is improved by about 42% compared with traditional products.

[0120] Example 3

[0121] Preparation of Inner Series Metallized Film

[0122] Preparation of Base Film:

[0123] 13 g of polyethylene terephthalate (PET) and 19.5 g of polyethylene naphthalate (PEN) were put into a twin-screw extruder. The temperature of each heating zone was set at 265 °C, 268 °C, 272 °C, 276 °C, and 279 °C. The screw speed was 112 rpm. The extruded thick sheet had a thickness of 2.6 mm. After cooling, it was longitudinally stretched 4 times at 170 °C on a stretching machine and then transversely stretched 4.2 times at 192 °C to obtain a base film with a thickness of 10.5 μm.

[0124] Barrier layer deposition:

[0125] The base film was placed in the reaction chamber of a low-pressure chemical vapor deposition (LPCVD) device. Silane (flow rate 14 sccm) and ammonia (flow rate 38 sccm) were introduced. The pressure was maintained at 140 Pa and the reaction was carried out at 740 °C for 42 minutes to deposit a barrier layer with a thickness of 70 nm.

[0126] First metal layer deposition:

[0127] In a plasma-enhanced chemical vapor deposition (PECVD) device, a copper layer was deposited on the base film with a barrier layer. After evacuating to an appropriate degree, argon (flow rate 35 sccm) and hydrogen (flow rate 15 sccm) were introduced, and a copper source gas was introduced. The deposition was carried out at 335 °C for 17 minutes, and the thickness of the copper layer reached 130 nm.

[0128] Buffer layer deposition:

[0129] Using the atomic layer deposition (ALD) process, nickel-chromium alloy (chromium atom ratio 23%) was used as the raw material. The deposition rate was set at 0.5 nm / cycle, and a buffer layer was deposited on the surface of the copper layer with a deposition thickness of 32 nm.

[0130] Transition layer deposition:

[0131] Using the magnetron sputtering process, a titanium-tantalum alloy (titanium atom ratio 75%) was used as the target. Argon (flow rate 25 sccm) was introduced, and the sputtering power was adjusted to 100 W. A transition layer was deposited on the buffer layer for 13 minutes with a thickness of 15 nm.

[0132] Second metal layer deposition:

[0133] A silver-palladium alloy second metal layer was deposited by the magnetron sputtering process. The palladium content accounted for 5% of the total mass of the alloy, the sputtering power was 160 W, and the deposition thickness reached 205 nm.

[0134] Antioxidant enhancement layer preparation and deposition**:

[0135] First, grow high-quality graphene on a copper foil substrate by chemical vapor deposition (CVD). Then, disperse alumina ceramic particles with a particle size of 120 nm in N-methylpyrrolidone (NMP) to form a dispersion. Let the graphene adsorb the ceramic particles and then transfer them to the surface of the second metal layer. After hot pressing and laminating, an antioxidant-enhanced layer with a thickness of 30 nm is formed.

[0136] Anti-reflection conductive layer deposition:

[0137] Deposit an indium tin oxide (ITO) thin film on the antioxidant-enhanced layer using a magnetron sputtering process. The argon flow rate is 50 sccm, the oxygen flow rate is 1.5 sccm, the sputtering power is 170 W, and the deposition time is 26 minutes to make the thickness reach 100 nm.

[0138] Patterning structure formation:

[0139] Use an electron beam lithography device to perform lithography according to the parameters of a regular hexagon side length of 4.5 mm for the conductive unit and an isolation bandwidth of 0.65 mm to form an inner series metallized thin film pattern.

[0140] Filter capacitor manufacturing and testing

[0141] Select three pieces of the inner series metallized thin film and a polytetrafluoroethylene thin film with a thickness of 2 μm to form a "sandwich" structure and wind it non-inductively for 15 turns.

[0142] Laser weld the gold foil lead electrodes, fix them and then install them in a ceramic shell (inner diameter 10.5 mm, height 21 mm), and pour silicone rubber potting glue with a filling rate of 95%.

[0143] Wait for the potting glue to cure, install the kovar alloy pins to complete the assembly. During testing, at a frequency of 1.2 MHz, the ESR of this filter capacitor is 4.2 mΩ, the withstand voltage reaches 670 V, and the filtering efficiency for high-frequency clutter signals is about 44% higher than that of traditional capacitors.

[0144] Through the detailed and comprehensive display of the above embodiments, it is further verified that when the inner series metallized thin film and its preparation method involved in the present invention are applied to the manufacture of filter capacitors, under different parameter settings and diverse test conditions, the expected high-performance performance can be stably achieved, effectively meeting the strict requirements of various complex electronic circuits for filter capacitors in different aspects, highlighting the innovation, practicality, and reliability of the present invention.

[0145] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An internally-connected metallized film, characterized in that: include: A base film, wherein the base film is made of a blend of polyethylene terephthalate and polyethylene naphthalate in a mass ratio of 2:3, and the thickness of the base film is 8-12 μm; A multi-layer metallization layer is arranged on the base film, including a first metal layer, a buffer layer and a second metal layer, wherein the buffer layer is located between the first metal layer and the second metal layer, wherein the first metal layer is a copper layer with a thickness of 100-150 nm, wherein the buffer layer is arranged on a side of the first metal layer away from the base film, wherein the buffer layer is a nickel-chromium alloy layer, wherein the atomic proportion of chromium is limited to the range of 20%-25%, and the thickness is 20-40 nm, and the second metal layer is a silver-palladium alloy layer, wherein the content of palladium accounts for 3%-6% of the total mass of the alloy, and the thickness is 180-220 nm; A patterned structure is provided, wherein a plurality of conductive units connected in series are formed on a multi-layer metallization layer, each conductive unit is a regular hexagon with a side length between 3 and 6 mm, and an isolation zone with a width of 0.3 to 0.8 mm is provided between adjacent conductive units.

2. The inner-series metallized film according to claim 1, characterized in that: The multilayer metallization layer also includes a barrier layer, a transition layer, an anti-oxidation enhancement layer, and an anti-transmittance conductive layer. The patterned structure is formed on the multilayer metallization layer as a whole consisting of the barrier layer, the first metal layer, the buffer layer, the transition layer, the second metal layer, the anti-oxidation enhancement layer and the anti-transmittance conductive layer.

3. The inner-series metallized film according to claim 2, characterized in that: The barrier layer is arranged between the base film and the first metal layer, and its thickness is between 50-100nm. The transition layer is located between the buffer layer and the second metal layer, and adopts an alloy material composed of titanium and tantalum, wherein the atomic proportion of titanium is 70%-80%, and the thickness is 10-20nm. The anti-oxidation enhancement layer covers the second metal layer, and is composed of a composite of graphene and inorganic ceramic particles, and the thickness ranges from 20-50nm, wherein the particle size of the inorganic ceramic particles is between 50-200nm. The anti-reflection conductive layer is arranged on the anti-oxidation enhancement layer, and adopts an indium tin oxide material, which is composed of 90% indium oxide and 10% tin oxide in a mass ratio, and the thickness is 80-120nm.

4. The method for preparing an inner-string metallized film according to claim 3, characterized in that: The following steps are involved: Preparation of base film: accurately weigh polyethylene terephthalate and polyethylene naphthalate raw materials according to the mass ratio of 2:3, put them into the hopper of a twin-screw extruder, and melt-blend them according to the set temperature ranges of 255°C-265°C, 260°C-270°C, 270°C-275°C, 275°C-280°C, 275°C-285°C and the screw speed, and control the screw speed at 100-120rpm to fully melt-blend the raw materials in the barrel, extrude a thick sheet with a thickness of 2-3mm through a die head, and after the thick sheet is quickly cooled to room temperature through a cooling roller, it is sent to a stretching machine to form a base film with a thickness of 8-12μm; Preparation of barrier layer deposition: the prepared base film is placed in the reaction chamber of the low-pressure chemical vapor deposition equipment, and the corresponding reaction gas is introduced according to the parameter conditions of silane flow rate 10-20sccm, ammonia flow rate 30-50sccm, reaction pressure 100-200Pa and reaction temperature 700-800℃, so that silane and ammonia react chemically on the surface of the base film, and the thickness of the barrier layer formed by the deposition reaches 50-100nm; Preparation of the first metal layer: The base film with the barrier layer deposited on it was smoothly transferred to the reaction chamber of the plasma enhanced chemical vapor deposition equipment, and the chamber was first evacuated to 5×10 -4 Pa, according to the parameters of argon flow rate 30-40sccm, hydrogen flow rate 10-20sccm, gas flow rate 40-60sccm, reaction temperature 300-350℃ and deposition time 15-20 minutes, and the power monitoring device is used to control the plasma power density at 0.5-1.5W / cm 2 Within the range, plasma enhanced chemical vapor deposition is performed to deposit a copper layer on the surface of the barrier layer; Buffer layer deposition preparation: Using the atomic layer deposition process, according to the nickel-chromium alloy composition and the deposition rate of 0.3-0.6nm / cycle, based on the characteristics of the selected atomic layer deposition equipment, a buffer layer is deposited on the surface of the existing metal layer to make the buffer layer thickness reach 20-40nm; Transition layer deposition step: The film with the buffer layer deposited is transferred to the reaction chamber of the magnetron sputtering equipment and first evacuated to 5×10 -4 Pa, introduce argon as sputtering gas, install an alloy material composed of titanium and tantalum with titanium atoms accounting for 70%-80% as a target material, adjust the sputtering power to 80-120W, and start depositing the transition layer. During the deposition process, the thickness of the transition layer reaches 10-20nm; Deposition of the second metal layer: adjust the parameters of the magnetron sputtering equipment, replace with silver-palladium alloy source gas, maintain the working gas pressure in the range of 0.1-0.5Pa, deposit the second metal layer on the surface of the transition layer, and deposit the thickness to 180-220nm; Patterned structure formation: carefully place the film coated with the above-mentioned multi-layer structure on the workbench of the electron beam lithography equipment, write a lithography program and input it into the electron beam lithography equipment according to the preset regular hexagonal shape of the conductive unit and the isolation zone width pattern parameters, and use the high-energy electron beam generated by the electron beam lithography equipment to expose the film according to the scanning path set by the program, and then go through the development and etching chemical treatment steps to remove the metallization layer in the isolation zone area, forming a conductive unit pattern connected in series, and obtaining an internally connected metallized film product.

5. The inner-series metallized film according to claim 4, characterized in that: Also includes the preparation and deposition of antioxidant enhancement layers: First, in the chemical vapor deposition equipment, according to the optimal process conditions for graphene growth, the flow rate, temperature, pressure of the reaction gas and the temperature of the substrate (copper foil) are precisely controlled to grow high-quality graphene on the copper foil substrate through chemical vapor deposition; Next, using ultrasonic dispersion equipment, according to the parameters optimized and set according to the dispersion effect of ceramic particles, such as ultrasonic dispersion power and time, alumina ceramic particles with a particle size of 50-200 nm are uniformly dispersed in an organic solvent to form a ceramic particle dispersion liquid; Then, the copper foil with graphene grown thereon is placed in the above dispersion and fully immersed therein, and the immersion time is determined according to the adsorption effect, so that the ceramic particles are fully adsorbed on the surface of the graphene; Afterwards, through a precise transfer process, the graphene composite layer with ceramic particles is transferred to the surface of the deposited second metal layer while ensuring the integrity of the graphene composite layer; Finally, a hot pressing device is used to reasonably set the hot pressing temperature, pressure, time and other parameters according to the material characteristics, and the hot pressing operation is performed to make the composite layer closely adhere to the second metal layer to form an anti-oxidation reinforcement layer with a thickness of 20-50nm; 6. The inner-series metallized film according to claim 5, characterized in that: It also includes the step of depositing an anti-reflective conductive layer: Place the film with the antioxidant enhancement layer in the reaction chamber of the magnetron sputtering equipment in physical vapor deposition, first evacuate the chamber to below 1×10-3Pa, introduce argon and oxygen as sputtering gases, install the target containing indium and tin, adjust the sputtering power to 150-200W, and adopt effective target cooling methods to ensure that the target temperature is maintained in an appropriate range to avoid overheating affecting the sputtering effect, and start depositing indium tin oxide film. By controlling the deposition time to 20-30 minutes, the thickness of the anti-reflective conductive layer reaches 80-120nm.

7. A filter capacitor, characterized in that: A filter capacitor manufactured by comprising the inner series metallized film as claimed in claim 6.