Standard Stackup Impedance Calculator 1.378mil BodyUp 2.7559mil FR4 Prepreg 1080 4.15 2.7559mil FR4 Prepreg 1080 4.15 1.378mil None 47.2441mil FR4 Core 4.55 1.378mil None 2.7559mil FR4 Prepreg 1080 4.15 2.7559mil FR4 Prepreg 1080 4.15 1.378mil BodyDown