We don't have synonyms for backplane yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are backplate, jackplane and backline.
(n) :
(electronics) A circuit board that connects several connectors in parallel to each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus.
(n) :
(electronics) A circuit board that connects several connectors in parallel to each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus.