PTFE PCB (PTFE printed circuit board) is a special circuit board with polytetrafluoroethylene (PTFE, commonly known as Teflon) as the substrate material, designed for high-frequency, high-speed and high-reliability pcb applications.
PTFE is a high-performance fluoropolymer material with the following key properties:
1. Good electrical properties:
Low dielectric constant (Dk): typically 2.1~3.0 (much lower than 4.5 of ordinary FR-4), reducing signal propagation delay.
Extremely low dissipation factor (Df): in the range of 0.001~0.004 (almost no energy loss at high frequencies), suitable for millimeter wave bands (such as 5G, radar).
2. High temperature resistance: work for a long time in an temperature environment of -200°C to +260°C.
3. Strong chemical stability: corrosion resistance, moisture resistance, acid and alkali resistance.
4. Good thermal stability: low coefficient of thermal expansion (CTE), small size change with temperature
1.High frequency/high speed requirements:
The signal propagation speed is inversely proportional to the square root of the dielectric constant. The low Dk of PTFE can significantly reduce signal delay and is suitable for high-speed digital circuits.
At high frequencies (such as 77 GHz in the millimeter wave band), traditional materials (such as FR-4 with Df≈0.02) will cause severe signal attenuation, while PTFE has almost no energy loss, ensuring signal integrity.
Therefore, 5G base station antennas, satellite communications (Ka band), and automotive autonomous driving radars (77GHz) must use PTFE PCBs, otherwise signal distortion will cause communication interruption or radar misjudgment.
2.Adaptability to extreme environments:
Wide temperature range (-200°C to +260°C)
able to work for a long time in high temperature (such as engine compartment) or ultra-low temperature (such as space environment), while FR-4 is prone to delamination and failure at high temperature.
3.Chemical stability and moisture resistance：
Resistant to strong acid and alkali corrosion, and almost no water absorption (moisture absorption rate <0.01%), suitable for humid or corrosive environments such as marine equipment and chemical sensors.
4.High power applications:
Low coefficient of thermal expansion (CTE≈10~20 ppm/°C)
Matches with the copper layer CTE to avoid solder joint cracking caused by temperature changes, suitable for high-power RF amplifiers (such as radar transmitter modules).
Excellent thermal conductivity (0.25 W/m·K)
Although not as good as metal substrates, it can dissipate heat more effectively than ordinary FR-4 and reduce the risk of thermal failure under high frequency and high power.
1.Wireless communication: 5G base stations, millimeter wave antennas, RF front-end modules.
2.Aerospace: satellite communications, radar systems, navigation equipment.
3.Automotive electronics: autonomous driving radar (77GHz), on-board high-frequency sensors.
4.Medical equipment: high-frequency imaging systems (such as MRI).
5.High-speed digital circuits: optical modules above 100Gbps, data center interconnection.
PTFE PCB is the first choice for high-frequency and high-reliability scenarios. Although it is expensive and complicated to process, its low loss and stability make it irreplaceable in the field of cutting-edge technology. When designing pcb, it is necessary to balance performance requirements and costs, and choose a reliable manufacturer with experience in PTFE PCB manufacturing process.