Issue link: https://resources.pcb.cadence.com/i/1541046
3. Finalizing the PCB Stackup Early Your PCB stackup (the order, thickness, and copper weight of each layer) directly impacts signal integrity, controlled impedance, EMI, crosstalk, return path quality, and manufacturability. Every design decision, from trace width to via style to power integrity, depends on the layer stackup's specifics. If you leave the stackup undefined until after routing, you risk traces that don't meet impedance, unexpected noise coupling, poor power delivery, and expensive late- stage redesigns. Even experienced designers sometimes assume the "standard stack" is sufficient, only to discover that it doesn't meet critical requirements for their product. When And Where To Apply Define and lock your stackup before placing or routing any components. This step comes immediately after establishing your board outline and importing mechanical constraints, and before you create impedance or length- matching rules. Any board with controlled impedance, multiple power domains, mixed analog/digital/RF, or strict EMC/EMI requirements must have a confirmed stackup. OrCAD X cross-section editor/layer stack manager allows you to define, edit, and manage a PCB layer stack-up for rigid, flex, or rigid/flex designs