Description
You can use FR4 materials for Stratix GX designs running at 3.125 gigabit per second (Gbps). However, the manufacturing process must be tightly controlled, specifically tight dielectric control, and trace width and layer height. You must take into account the worst case variation in all these parameters and ensure that the line impedance does not vary by more than 10%.
FR4 is the most commonly used dielectric material in today's printed circuit boards. FR4 is composed of woven glass and epoxy resin giving it the rigidity required for mass produced boards.