IPC Certified Interconnect Designer (CID) Practice Exam

Legend layers, the silkscreen on a PCB, are typically the final surface layer applied. In most layer stacks, copper signal layers and solder mask come earlier, while text, logos, and reference marks printed on the board surface (the legend layer) are added last so they sit on top and remain readable after fabrication steps. This is why legend layers typically have the highest layer number in the convention. The other options are used earlier in the process: solder mask sits beneath the silkscreen to protect copper surfaces, signal layers are the actual copper circuitry, and mechanical layers describe the board outline and non-electrical features.