1.FR-4

When selecting a PCB substrate for high frequency circuits, pay special attention to the materials used. For many years, the standard circuit board material currently used in the market has been FR-4, a flame-retardant type 4 woven glass-reinforced epoxy laminate. This high frequency pcb materials are very cost effective and easy to use, making it ideal for high frequency pcb manufacturers as FR-4 material. It is also a perfect electrical insulator and a robust material for printed circuit boards.

2.Rogers, Isola, Taconic, Dupont, and Megatron

If there are a requirement for high frequency pcb in terms of signal transmission at high speed or characteristic impedance control requirements. In this case, the focus is on the DF and its performance under frequency, temperature, and humidity conditions. The choice of PCB board must be to meet the design requirements, mass production, cost in the middle to strike a balance.
In simple terms, the design requirements include the electrical and structural reliability of the two parts. Usually, in designing a very high-speed PCB board (greater than GHz frequency), the board issue will be more important. For example, now commonly used FR-4 material, in several GHz frequency dielectric loss Df (Dielectricloss) will be very large, may not be suitable.The most common high frequency pcb are Rogers, Isola, Taconic, Dupont, and Megatron materials. All of these materials typically have low Dk and low loss.

3.Teflon and flexible substrates

In terms of price, FR4 is the cheapest compared to dedicated high-speed materials and Teflon, with Teflon being the most expensive. However, the performance of FR-4 starts to degrade when the signal speed exceeds 1.6 GHz. Therefore, DK, Df, water absorption, environmental survivability, next-generation substrates, Teflon, and flexible circuits are the best choices.
If a printed circuit board requires frequencies above 10 GHz, next-generation substrates, Teflon, and Flex substrates are your best choices because they are far superior to traditional FR-4 materials. Another consideration for making high frequency pcb is the moisture absorption rate of the material used in the board.
Even a tiny amount of moisture can change the electrical properties of a high frequency circuit. Traditional FR-4 can absorb up to 50% moisture, while high frequency pcb materials such as PTFE can absorb as little as 2%. That’s why high frequency pcb manufacturers generally choose FR-4 materials first.