H ELECTRICITY
H05 ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
H05K PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
H05K1/00 Printed circuits
H05K1/14 Structural association of two or more printed circuits
H05K1/141 One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters