PURPOSE: To prevent a sub printed-wiring board from being lifted, enable reliability in electrical and mechanical connection to be increased, and prevent a circuit pattern of a main printed-wiring board from being damaged even if burr is formed on the sub printed-wiring board in a combinational printed-wiring board where the sub printed-wiring board is surface-mounted on the main printed- wiring board.

CONSTITUTION: Circuit patterns 2 and 5 and land portions 3 and 6 for connection are formed on a main printed-wiring board 1 and a sub printed-wiring board 4, respectively. A recessed portion 7 is formed so that a land portion 6 is penetrated through facing a mounting surface 9 to the main printed-wiring board 1 of the sub printed-wiring board 4 and then a protruding portion 12 is formed on the mounting surface 9 so that an opening of a recessed portion 7 is separated from the main printed-wiring board 1. While the projecting portion 12 of the sub printed-wiring board 4 is in contact with the main printed-wiring board 1. land portions 3 and 6 of the main printed-wiring board 1 and the stub printed- wiring board 4 are connected by a solder 10, thus forming a combinational printed-wiring board.