A package-on-package structure is provided to reduce a degree of warpage and to reduce the number of bumps by connecting electrically a first and second packages through wires. A first semiconductor chip(115) includes a plurality of first internal terminals(134) and a plurality of first external terminals(136) and is disposed on a first substrate(110). A second semiconductor chip(125) includes a plurality of second internal terminals(144) and a plurality of second external terminals(146) and is disposed on a second substrate. A connective structure(200) is formed to connect at least one of the first external terminals to at least one of the second external terminals. The first semiconductor chip is connected through a first bonding unit(132) to the first internal terminals of the first substrate. The second semiconductor chip is connected through a second bonding unit(142) to the second internal terminals of the second substrate. The first bonding unit is a wire bonding structure or a solder bump structure. The second bonding unit is formed with one of the wire bonding structure or the solder bump structure.
