PURPOSE: To improve appearance, improve contact with an IC card data processing device, and improve reliability by providing holes on a first board and a second board staggering each other and by performing through-hole plating to the hole of the first substrate.

CONSTITUTION: A first hole 20 is provided on a first board 1, while a second hole 21 is provided on a second board 2. The first and second boards are provided while they are shifted from each other so that the first and second holes 20 and 21 do not communicate each other when the rear surfaces of the first and second boards 1 and 2 are applied each other. A through-hole plating 22 is applied to the first hole 20. The through-hole plating 22 is formed on the surface of the first board and connected to a first wiring 4 which passes through the first hole 20. Solder or a conductive adhesive 7 is filled into a second hole 21 of the second board 2. Then, a second wiring 6 of the second board passing through the second hole 21 and a third wiring 5 which is formed on the rear surface of the first board 1 are connected each other.