The main difference between high frequency PCB and conventional PCB is that they use laminated materials, while the former material shows very special characteristics. Compared with the traditional FR-4 material, the high frequency plate uses more advanced composite materials, which have special requirements for dielectric constant, loss tangent and coefficient of thermal expansion.Manufacturing high frequency PCB also requires special skills that traditional manufacturers using standard PCB technology may not have. High frequency plates not only need special design technology, but also manufacturers must use special laminates to manufacture them. At the same time, they should pay attention to specific material selection, DFM inspection and high quality control to ensure that the product can play a role in the whole life cycle.Several manufacturers have made laminates for high frequency applications. Some famous names are Taconic, polyclad, Isola, Hitachi, asaki, metclad and Rogers. However, different applications have different requirements and budgets, and designers must negotiate with contract manufacturers to use the most appropriate materials to meet their applications and budgets.Manufacturing high frequency boardAll laminates have their own manufacturing problems. In order to obtain the required quality and reliability, for each material, the corresponding manufacturing instructions must be followed for processing, storage, surface treatment, inner treatment, drilling, bonding, deburring and electroplating.Special process is needed to manufacture PCB containing HF material. For example, the preparation of via plating is a key process, especially for PTFE substrate. PTFE requires a special back etching process and plasma etching setup to prepare the hole surface for electroless copper plating. Therefore, in the case of the correct selection of materials, the correct manufacturing method is also essential for obtaining high quality printing plate and high frequency work.
