High-frequency PCBs utilizing polytetrafluoroethylene (PTFE) as their PCB substrate are known as Teflon PCBs or PTFE PCBs. Teflon PCBs transmit impulses at frequencies up to 5 GHz. Dupont Corporation markets its PTFE materials under the name Teflon, and because of its widespread recognition, people often referred to PTFE substrate PCBs used only for microwave applications as Teflon PCBs.
Because they work well in high-frequency electrical applications, Teflon materials are prized. Teflon PCB laminates aren’t made of pure PTFE; instead, they’re made of PTFE-based composites since PTFE makes copper layers difficult to connect and needs reinforcement for its stiffness & thermal resistance. PTFE is used with ceramics, glass fiber, glass, or woven glass to strengthen the Teflon PCB substrate.
Advantages of using Teflon for PCB fabrication
- Lower coefficient of friction: Teflon has a low coefficient of thermal expansion because to its smooth, non-stick surface.
- Low thermal expansion coefficient: Its Tg ranges from 160 to 280 °C (sometimes more). This fact explains why we use Teflon in cookware. They’re also ideal for extremely precise electrical gadgets that generate a lot of heat owing to power use.
- Teflon PCBs have exceptional chemical tolerance and excellent chemical resistance. As a result, they are extremely resistant to corrosion caused by moisture, oil, and other substances.
- Teflon has a low common dissipation factor, which makes it leak-resistant and ideally suited for high-frequency & microwave application. This quality also provides them exceptional weather resistance.
The mechanical rigidity of PTFE PCBs is extraordinary. They are also tough, resisting oxidation (rust) brought on by moisture as well as sunshine.