en 
Wechat QRcode
Hotline:0755-22277778
Tel：0755-22277778
Mobile：13826586185（Mr.Duan）
Fax：0755-22277776
E-mail：duanlian@xianjinyuan.cn
2.3 μ m PET aluminum plated film · ultra-thin capacitor substrate
In the design of metalized film capacitors, the thickness of the dielectric film directly determines the volumetric efficiency of the capacitor - the thinner the film, the greater the capacitance per unit volume. Over the past few decades, the thickness of PET film has gradually decreased from the early 12 μ m to 6 μ m and 4.5 μ m, and has now advanced to 2.3 μ m.
What is the concept of 2.3 μ m? As a reference, the diameter of a standard adult hair is approximately 60-80 μ m. The thickness of PET film with a thickness of 2.3 μ m is only about one thirtieth of the diameter of a hair. At this scale, PET film is approaching its physical limit as an independent film - thinner means facing significant process challenges in winding, coating, and slitting processes.
�� Core Insights:It is precisely this "extreme thinness" that makes 2.3 μ m PET aluminum plated film irreplaceable in high-end capacitors and precision electronic applications that require extreme miniaturization.
The aluminum layer preparation of 2.3 μ m PET aluminum coated film adopts vacuum evaporation process - in a high vacuum environment, high-purity aluminum is heated to the evaporation temperature (about 1200-1400 ° C), and the aluminum vapor is condensed and deposited on the surface of the high-speed running PET film, forming a layer of metallic aluminum. The thickness of the aluminum layer is usually in the range of 20-100 nanometers.
Vacuum deposition on ultra-thin substrates with a thickness of 2.3 μ m faces a series of technical challenges that are far more stringent than conventional thickness substrates:
2.3 μ m PET has extremely low thermal capacity and requires precise control of evaporation temperature, speed, and substrate operating speed to prevent shrinkage, warping, or melting.
The mechanical strength of extremely thin substrates is limited, and a precise low tension control system is the core threshold for mass production.
Any small defect can become a penetrating pinhole, and low pinhole aluminum coating is a core requirement for high-end applications.
Accurately regulate the evaporation rate and substrate speed to achieve nanoscale control of aluminum layer thickness.
PET is one of the most common dielectric materials in metallized film capacitors. PET film has a high dielectric constant and excellent self-healing properties, with a working temperature of up to 125 ° C.
The core engineering value of 2.3 μ m PET substrate lies in its volumetric efficiency. The capacitance of a capacitor is inversely proportional to the thickness of the dielectric - the thinner the film, the greater the capacitance within the same volume. For thin film capacitors that require stable operation in high current and high ripple scenarios, a 2.3 μ m ultra-thin PET substrate can achieve higher capacitance density in a limited space.
Process collaboration:The internal electrodes of metallized film capacitors are ultra-thin metal layers (usually aluminum or zinc aluminum alloy) deposited on the surface of the film through vacuum coating technology. The combination of 2.3 μ m PET substrate and nanoscale aluminum coating has pushed the miniaturization of capacitors to a new height.
Based on a 2.3 μ m PET substrate, aluminum plated film products with different aluminum layer thicknesses can be prepared by precisely controlling the evaporation process parameters. The thickness of the aluminum layer (characterized by optical density OD value) ranges from 0.1 to 0.7, and different thicknesses correspond to different performance focuses:
| Product Type | Optical density (OD) | Aluminum layer thickness | Key Features | Typical Applications |
|---|---|---|---|---|
| 2.3 0.1PET aluminum plated film | ~0.1 OD | Extremely thin aluminum layer | Extremely flexible, semi transparent, and lowest material cost | Ultra thin capacitors, precision optical films, low barrier packaging |
| 2.3 0.3PET aluminum plated film | ~0.3 OD | Thin aluminum layer | Good flexibility and moderate barrier properties | Metallized film capacitors, electronic shielding |
| 2.3 0.7PET aluminum plated film | ~0.7 OD | Thicker aluminum layer | High reflectivity, strong conductivity, and high barrier properties | High reliability capacitors, X-ray detectors, high-end EMI shielding |
Note: The higher the optical density (OD) value, the thicker the aluminum layer, and the higher the barrier and reflectivity.
Selection suggestion:The lower the OD value, the better the flexibility and the stronger the winding adaptability; The higher the OD value, the stronger the conductivity and barrier properties. Balancing capacitance density, flexibility, and barrier requirements comprehensively.
2.3 μ m is one of the ultra-thin specifications for PET film that can be mass-produced, approaching the physical limit and requiring extremely high precision in process control.
20-100 nanometers, the thicker the barrier and conductivity, but the flexibility decreases.
The aluminum plating layer reduces the oxygen/water vapor permeability by more than 99%, effectively blocking ultraviolet and infrared rays.
The visible light reflectivity of the aluminum plated surface is ≥ 90%, and the reflectivity of the aluminum surface can reach 95%.
The long-term use temperature of PET substrate is 125 ° C, and it remains basically unchanged after aluminum plating.
Core applications. The 2.3 μ m ultra-thin substrate achieves higher capacitance in limited packaging space and is widely used in consumer electronics, automotive electronics, and industrial power supplies.
2-3 μ m low pinhole aluminum coating ensures X-ray transmittance while providing conductivity and light shielding for detector assembly lines.
Ultra thin shielding layer can fit into narrow spaces that traditional shielding materials cannot enter.
Used for electrodes, antennas, sensors, optical reflective films, and sensor substrates in thin film capacitors.
The higher the OD value, the stronger the barrier and conductivity, but the flexibility decreases. Capacitor selection based on voltage/capacity; The detector needs to balance conductivity and X-ray transmittance.
Ultra thin substrate pinhole control is a core quality indicator, and high-end applications such as X-ray detectors have strict requirements for pinhole density.
The 2.3 μ m film is prone to wrinkling and fracture, and its compatibility with existing winding equipment needs to be evaluated.
The long-term use temperature of PET is 125 ° C, and if it exceeds this, higher temperature resistant substrates such as PEN or PI should be considered.
The essence of 2.3 μ m PET aluminum coated film is an engineering product that pushes the thickness of PET film to its physical limit. It is not simply "thinning" - at a scale of 2.3 μ m, material tension control, temperature management, pinhole suppression, and coating uniformity all face engineering challenges that are far more stringent than conventional thickness substrates. It is precisely these boundary conditions that have been overcome one by one that enable the 2.3 μ m PET aluminum coated film to move from the laboratory to mass production, becoming the core material for high-end applications such as metalized thin film capacitors, X-ray detectors, and precision electronics.
For engineers, understanding the process constraints and performance opportunities behind the thickness of 2.3 μ m - why it is 2.3 μ m instead of thinner, and how to choose the OD value - is more valuable than simply remembering a specification.
www.avanzado.cn
© 2026 Xianjin Yuan · 2.3μm PET Metallized Film Technical Reference
Advanced Institute (Shenzhen) Technology Co., Ltd， © two thousand and twenty-onewww.xianjinyuan.cn. All Rights Reserved.Guangdong ICP No. 2021051947 sitemap
Español
Français
Português