A multi-chip package type semiconductor device includes an insulating substrate having first and second conductive patterns thereon, a first semiconductor chip on the insulating substrate and having a first terminal pad and a relay pad isolated from the first terminal pad. The device further includes a second semiconductor chip on the first semiconductor chip having a second terminal pad. The first semiconductor chip is connected to the first pattern by a first bonding wire. The second semiconductor chip is connected to the second pattern by a second bonding wire, which connects the second pattern to the relay pad, and a third bonding wire, which connects the relay pad to the second terminal pad. The lengths of the first, second and third bonding wire are approximately the same.