For example, how is the multiple laminate performance, temperature performance, CAF/heat resistance, mechanical toughness (adhesion) (good reliability), and fire resistance rating.
2. Various performances (electrical performance, stability, etc.) supporting the product:
Low loss, stable DK/DF parameters, low dispersion, small variation coefficient with frequency and environment, small tolerances on material thickness and glue content (good impedance control). If the wiring is very long, consider low-roughness copper foil. On the other hand, simulation is needed in the early stage of high-speed circuit design, and the simulation result is the reference standard for design.
3. Timely availability of materials:
Many high-frequency CCL have a very long procurement cycle, even 2-3 months; in addition to the conventional high-frequency CCL RO4350 in stock, many high-frequency CCL need to be provided by customers. Therefore, to order high-frequency CCL, you need to communicate with the manufacturer in advance and prepare the materials as early as possible.
4. Cost factor:
It depends on the price sensitivity of the product, whether it is a consumer product, or a communication, medical, industrial, or military application.
5. Applicability of laws and regulations, etc.:
It must be compliant with the environmental regulations of different countries and meet the requirements of RoHS and halogen-free.
Among the above factors, the operating speed of high-speed digital circuits is the main factor considered in PCB selection. The higher the circuit speed, the smaller the selected PCB DF value. Medium and low loss circuit boards are suitable for 10GB/s digital circuits; low loss boards are suitable for 25GB/s digital circuits; ultra-low loss CCL will adapt to faster high-speed digital circuits, and the speed of it can reach 50GB/s or higher.