PI Gold Plated Film | When the "Golden Film" Meets the Precious Metal Coating - Conductive and Shielding Substrate under Extreme Working Conditions

1、 PI: What is the special feature of polymer materials known as "golden films"

Polyimide is known as the "golden film" not only because of its high price, but also because it stands at the top of the performance pyramid of polymer materials.

Temperature resistance is the hardest core label of PI. PI film can be used for a long time in the extreme temperature range of -269 ℃ to 400 ℃, with a thermal expansion coefficient as low as 12ppm/℃, ensuring dimensional stability in severe temperature difference environments. Whether it's extreme cold in space, high temperature in the engine compartment, or thermal shock in reflow soldering processes, PI can handle it with ease.

The mechanical performance is equally outstanding. The tensile strength of PI film is greater than 200MPa, possessing excellent mechanical strength and suitable for complex processing techniques. At the same time, it also has good flexibility, which can meet the design requirements of different shapes and structures.

Insulation performance and radiation resistance are another major advantage of PI. PI has excellent dielectric properties, low dielectric constant and dielectric loss tangent, which can effectively reduce signal transmission losses. At the same time, PI has excellent resistance to high-energy radiation, making it an ideal substrate for aerospace electronic equipment.

2、 When the "gold film" is coated with real gold: 1 1>2 performance transition

Plating a layer of gold on the surface of PI film is not a simple "gilding" - it is a precise functional upgrade.

The chemical stability of gold solves the shortcoming of PI being non-conductive. PI itself is an excellent insulating material, and the gold coating endows it with excellent conductivity. The conductivity of gold is second only to silver, and the conductivity of the gold plating layer can reach over 40MS/m. The surface resistance can be stabilized at 0.02 Ω/sh. This conductivity level allows it to directly replace traditional metal foils in flexible circuits and electromagnetic shielding scenarios.

The gold coating also brings the value of a "protective layer". Gold has extremely high chemical stability and is not prone to chemical reactions with substances such as oxygen and water. Under an environment of 85 ℃/85% RH for 1000 hours, there was no peeling or discoloration of the PI gold plating film. After continuous immersion in liquid nitrogen at -196 ℃ for 1000 hours, the coating showed no bubbles. Soak in 10% hydrochloric acid solution for 30 days, with a weight loss of less than 0.01%.

But the biggest technical difficulty of PI gold plating is that "plating on" and "plating firmly" are two different things. PI has low surface energy and strong chemical inertness, making it difficult to form a strong bond through direct deposition of gold atoms. Advanced Institute Technology adopts ion beam assisted deposition technology to create a uniform "honeycomb like" concave convex structure on the surface of PI at the microscopic level, providing an "anchor point" for gold layer deposition. Verified by the hundred grid test, the adhesion of the coating meets the 5B level standard - which means that even after repeated bending and high-temperature welding, the gold layer will not bubble or peel off.

3、 Thickness is the scene: 12.5 μ m to 100 μ m, each thickness corresponds to a specific requirement

The thickness selection of PI gold plating film directly determines its application boundary.

12.5 μ m - Ultra slim and lightweight. The thickness is only equivalent to one sixth of the diameter of a hair strand. Suitable for scenarios with extreme requirements for space and weight, such as foldable phone hinges and wearable devices. A certain international brand applied it to the hinge part of foldable mobile phones, achieving an industry record of 200000 folds without damage. After 100000 dynamic bending tests, the resistance change rate remained within ± 0.5%.

25 μ m - Balanced universal type. Balancing flexibility and mechanical strength, suitable for mainstream electronic manufacturing scenarios such as flexible circuit boards (FPCs) and printed circuit boards. In the frequency range of 1GHz to 18GHz, the average shielding effectiveness is greater than 80dB. In the frequency range of 10MHz to 3GHz, the shielding effectiveness is as high as 70dB or more, significantly better than the average 50dB of traditional copper plates.

50 μ m - structurally enhanced type. Suitable for scenarios that require higher mechanical strength, such as key components such as cable shielding layers inside aerospace vehicles and satellite antennas. The satellite solar wing adopts PI gold plating film as the thermal control coating, which reduces the temperature fluctuation range in orbit to ± 1.5 ℃.

100 μ m - industrial heavy-duty type. Suitable for scenarios with the highest requirements for structural strength and durability, such as high reliability industrial equipment and medical electronics. In medical endoscopes, the imaging clarity is improved by 40% through the design of local gold plating thickness gradient (continuous transition from 0.03 μ m to 0.3 μ m).

4、 From Folding Screen to Satellite: The Four Major Application Maps of PI Gold Plated Film

Folding screens and flexible electronics are the most representative application scenarios for PI gold-plated films. Traditional rigid connecting wires are prone to breakage during frequent folding. The PI gold-plated film of Advanced Institute Technology can maintain good conductivity even after countless bends, truly achieving the concept of "softness with rigidity".

Aerospace represents the highest dimension of reliability requirements. PI gold-plated film is used to manufacture key components such as satellite antennas, solar cell array substrates, and spacecraft thermal control systems. A certain type of satellite solar wing uses PI gold-plated film as a thermal control coating, which reduces the temperature fluctuation range of the satellite in orbit to ± 1.5 ℃. In a certain type of high-energy laser system, a 500mm wide gold-plated film is used as the reflector substrate to withstand an energy density of 10 megawatts per square centimeter without deformation.

5G communication and high-frequency radio frequency are the fastest-growing markets for PI gold-plated films. 5G communication has put forward strict requirements for high-frequency signal transmission. The low dielectric loss and high conductivity of PI gold-plated film make it an ideal shielding and conductive material for 5G base stations, RF front-end modules, and antenna systems.

Medical electronics and precision instruments are the fields where PI gold-plated films are rapidly penetrating. The combination of gold's biocompatibility and PI's flexibility makes it uniquely valuable in cutting-edge applications such as implantable medical devices, neural probes, and biosensors.

5、 Customization: Match according to needs from thickness to width

Advanced Institute Technology provides four standard thicknesses of 12.5 μ m, 25 μ m, 50 μ m, and 100 μ m, and supports full range customization from 5 μ m to 125 μ m. The width is available in two specifications: 250mm and 500mm. The surface roughness is controlled at Ra<0.05 μ m, and the reflectivity reaches 98.2%. The thickness of the gold plating layer can be adjusted within the range of 0.02 μ m to 0.1 μ m. The company has passed ISO9001 certification and its products comply with GJB 773A aerospace standards and RoHS environmental requirements.

The global flexible substrate market is estimated to reach $7.516 billion in 2024 and is expected to grow to $22.452 billion by 2032. PI gold-plated film, with its comprehensive advantages in four dimensions of "extreme temperature resistance, high conductivity, strong shielding, and super flexibility", is moving from "high-end professional materials" to standard functional substrates for precision manufacturing in multiple fields.

Advanced Institute (Shenzhen) Technology Co., Ltd. will continue to deeply cultivate the field of PI gold plating film, providing customers with higher performance and more reliable flexible substrate precious metal coating solutions through precision coating technology and continuous technological innovation.