PPS Gold Plating Film | When "Plastic Gold" Meets Precious Metal Coating - Redefining High Temperature, High Frequency Electronics and Extreme Environment Functional Substrate

1、 PPS: Where does the confidence of "plastic gold" come from

Polyphenylene sulfide (PPS) is a thermoplastic special engineering plastic with a molecular structure containing repeating units of p-phenylene sulfide. This unique molecular structure endows PPS with a series of nearly "golden grade" comprehensive properties.

High temperature resistance is the core label of PPS. PPS film can be used continuously for a long time at temperatures ranging from 200 ℃ to 240 ℃, and its short-term temperature resistance can exceed 260 ℃. This characteristic enables it to exhibit excellent dimensional stability in reflow soldering processes - for electronic components that require multiple reflow soldering cycles, the heat-resistant redundancy of PPS substrate means higher process yield and longer service life.

Low dielectric loss is PPS's trump card in the field of high-frequency communication. The new low dielectric PPS film developed by DIC and Unitika in Japan exhibits stable dielectric properties in a wide frequency range of 10GHz to 1000GHz. The low dielectric PPS material launched by Guhe Electric has a dielectric constant (Dk) of only 1.6 at a frequency of 2.45 GHz, and a dielectric loss factor (Df) as low as 0.0015- this data means that the signal transmission loss is compressed to the extreme. In addition, PPS material itself has self extinguishing properties and can meet UL94 VTM-0 flame retardant standards without the need to add flame retardants.

However, PPS itself is an excellent insulating material, lacking functions such as conductivity, thermal conductivity, and electromagnetic shielding - which is precisely the value of gold plating technology.

2、 PPS Gold Plating: When "Plating on" Meets "Plating Firmly" - Advanced Institute's Technology Breaks the Ground

Metallization of PPS is not an easy task. PPS molecular chains contain a large number of benzene rings and sulfide bonds, with strong chemical inertness and low surface energy. Direct gold plating is prone to coating detachment. At the same time, the stress mismatch between the high hardness gold layer and the PPS substrate makes the coating prone to cracking during bending or thermal cycling. In addition, the diffusion of sulfur elements in PPS may have adverse effects on the conductivity of certain metal coatings.

Advanced Institute Technology has been deeply involved in the field of flexible substrate coating for many years, and has developed systematic solutions to the above-mentioned difficulties.

Substrate pretreatment is the first step and also the determining factor for success or failure. The combination process of "organic solvent ultrasonic cleaning low-temperature plasma activation" is adopted to etch micro nano anchoring structures on the surface of PPS, while introducing active groups such as hydroxyl and carboxyl groups, greatly improving the surface energy of the substrate. This step lays the foundation for the firm bonding between the subsequent metal layer and the substrate.

The gradient transition layer design solves the stress matching problem. In response to the significant difference in modulus between PPS and the gold layer, Advanced Institute Technology has introduced a gradient transition layer design. By depositing multiple layers of intermediate layers with different compositions, stress gradient transition from the substrate to the gold layer is achieved, effectively alleviating interface stress concentration during thermal cycling and mechanical bending processes.

Magnetron sputtering gold plating ensures the density and uniformity of the coating. In a vacuum environment, high-speed charged particles bombard a gold target material, causing gold atoms to break free from the binding of the target material and deposit uniformly on the surface of PPS. The particle size of the gold layer prepared by magnetron sputtering is about 60nm, and the surface roughness is controlled between 100-175nm. Advanced Institute Technology has successfully developed a low-temperature gold plating process, reducing the film processing temperature to below 150 ℃, effectively avoiding the thermal deformation problem of PPS films at high temperatures.

3、 Data speaking: What can PPS gold plating film do?

The performance of PPS gold plating film ultimately needs to be proven by data.

In terms of conductivity, the surface resistivity can be as low as 10 Ω· cm. The thickness of the gold layer can be precisely controlled within the range of 0.1 μ m to 5 μ m. This level of conductivity is sufficient for scenarios that require high conductivity, such as high-frequency signal transmission and electromagnetic shielding.

In terms of high temperature reliability, PPS gold-plated film electrodes can work stably in high temperature environments above 200 ℃. The industrial sensors of a research institute in Hangzhou need to work stably in a wide temperature range of -40 ℃ to 180 ℃, while also requiring resistance to salt spray corrosion and electromagnetic shielding performance. Advanced Institute Technology adjusted the molecular weight distribution of PPS substrate and the composition ratio of coating according to its needs, and the final sample maintained conductivity after 1000 hours of salt spray testing, with a shielding effectiveness exceeding 60dB.

In terms of electromagnetic shielding, PPS gold plating film has a shielding efficiency of over 60dB in the 10GHz frequency band, meeting aerospace grade standards. 60dB means that 99.9% of electromagnetic waves are effectively blocked. In higher demand high-frequency communication scenarios, PPS gold plating film also performs well.

In terms of thickness customization, Advanced Institute Technology can provide PPS gold plating film customization services ranging from 2 μ m to 125 μ m. Ultra thin coating (<5 μ m) is suitable for high-frequency signal transmission scenarios and can minimize signal loss to the greatest extent possible; Thickened coating (>20 μ m) is suitable for scenarios such as automotive connectors that require high wear resistance.

4、 Three major application battlefields: from 5G base stations to spacecraft

5G/6G high-frequency communication is the fastest-growing application field for PPS gold plating film. The operating frequency of 5G millimeter wave and future 6G communication systems has climbed to 28GHz or even higher, placing unprecedented demands on the dielectric properties of substrates. The low dielectric constant and low loss factor characteristics inherent in PPS significantly reduce signal transmission losses. PPS gold plating film is widely used in key components such as high-frequency connectors, RF devices, filters, etc. in 5G base stations. Koga Electric of Japan has launched low dielectric PPS material, which can reduce 5G/6G high-frequency dielectric loss - this trend confirms that PPS's technical value in the field of high-frequency communication is widely recognized by the industry.

Aerospace and military electronics represent the application scenarios where PPS gold plating film has the highest reliability requirements. The aerospace industry has extremely demanding performance requirements for materials, requiring various characteristics such as high temperature resistance, corrosion resistance, and high strength. PPS gold plating film meets the requirements of cold and hot cycling from -55 ℃ to 280 ℃, and can be used to manufacture electronic equipment casings, sensor components, etc. for aerospace vehicles. PPS gold plating film can ensure the normal operation of electronic devices in high-temperature and high radiation space environments. There are clear technical standards for the surface metal coating of special non-metallic materials used in aerospace, covering nickel gold, nickel silver and other coating processes for PPS and other materials. PPS gold plating film occupies a place in military electronic chassis, radar systems, satellite communication equipment and other scenarios due to its dual advantages of extreme temperature resistance and high reliability.

Automotive electronics and industrial control are one of the markets with the highest demand for PPS gold plating film. With the deep evolution of automobiles towards electrification and intelligence, the engine compartment temperature continues to rise and the density of electronic control units continues to increase. PPS gold plating film is widely used in components such as sensors and connectors. Japanese DIC has developed electroplated PPS compounds to provide weight reduction and EMI shielding advantages for automobiles - replacing metal with plastic and providing EMI shielding in applications that require durability, including electronic device casings and connectors. PPS gold plating film, which can withstand repeated sterilization, is gradually replacing traditional metal components for high-precision medical equipment such as endoscopes and surgical instruments.

5、 Customization: From thickness to performance, match as needed

The performance requirements for PPS gold plating film vary significantly in different application scenarios. Advanced Institute Technology provides customized services with thicknesses ranging from 2 μ m to 125 μ m through modular production processes. The thickness of the gold layer can be controlled within the range of 0.1 μ m to 5 μ m. The company has passed ISO9001 certification and its products comply with GJB 773A aerospace standards and RoHS environmental requirements.

The global PPS cast film market is expected to continue expanding at a compound annual growth rate of 3.8% -4.1%. The global PPS resin market is estimated to reach $1.16 billion by 2025. Driven by the deployment of 5G/6G communication, upgrading of aerospace equipment, and deep evolution of automotive electrification and intelligence, PPS gold plating film, which combines high temperature resistance at 260 ℃, low dielectric loss, high conductivity, and strong shielding, is moving from a "high-end professional material" to a standard option for functional substrates in the high-temperature and high-frequency electronic field.

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