In PCB lamination, “resin flow” (molten prepreg resin overflow under high temp/pressure) often causes impedance deviation, especially impacting high-frequency signal transmission. This article concisely explains its impact paths and control measures. I. Three Core Paths of Resin Flow Affecting Impedance 1. Uneven Dielectric Thickness: Lower Edge Impedance More resin flows at board edges, thinning dielectric […]