Semiconductor device having capacitive insulation means and communication terminal using the device

A primary side circuit and a secondary side circuit are provided on first and second semiconductor substrates, respectively. A first capacitive insulator on the first substrate electrically insulates and isolates between the primary and secondary side circuits while permitting signal transmission between these circuits. A second capacitive insulator on the second semiconductor substrate electrically isolates the primary and secondary side circuit while permitting signal transmission therebetween. First and second frames are provided for input and output of signals to and from the primary and secondary side circuits. External electrodes of the first and second capacitive insulators are connected together by a third lead frame via a conductive adhesive body including more than one solder ball. The first and second substrates and the lead frames are sealed by a dielectric resin.