= system board = base board = logic board

olemus
ComputerLanguage.com:
esmane trükkplaat arvutis või muus elektroonikaseadmes
= the primary printed circuit board in a computer or other electronic device

ülevaateid
https://www.quora.com/What-is-the-difference-between-mainboard-and-motherboard
https://jamindopcba.com/what-is-a-main-pcb/