1.Adapted permittivity.

2.Low attenuation for efficient signal transmission.

3.Homogeneous construction with low tolerances in insulation thickness and dielectric constant.

Generally speaking, high frequency can be defined as frequency above 1GHz.Currently, PTFE material is widely used in high frequency PCB manufacturing, it's also called Teflon, which frequency is normally above 5GHz.In addition, FR4 or PPO substrate can be used to the product frequency among 1GHz~10GHz.

PCBsupplierChina  talked,these three high frequency substrate have below differences:

With regard to laminate cost of FR4, PPO and Teflon, FR4 is the cheapest one, while Teflon is the most expensive one.In terms of DK, DF, water absorption and frequency feature, Teflon is the best.When product application require frequency above 10GHz, only can we choose Teflon PCB substrate to manufacture.

Obviously, the performance of Teflon is far better than other substrate, However, Teflon substrate has the disadvantage of high cost and large heat resisting property.

In order to improve PTFE stiffness and heat resisting property function, a large number of SiO2 or fiber glass as the filling material.On the other hand, due to molecule inertia of PTFE material, which it is not easy to combine with copper foil, thus, it needs to do special surface treatment on the combination side.

With regard to combination surface treatment, normally use chemical etching on PTFE surface or plasma etching to plus surface roughness or add one adhesive film between PTFE and copper foil, but these may have influence on dielectric performance.

Sun&Lynn （深联电路）talked ，If your PCB&FPC project involves some non-standard requirements, then you may need an experienced professional manufacturer to deal with similar specifications.If you have any special requirements about PCB&FPC, you may wish to contact us directly.