| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent a surge current from flowing into an internal circuit. <P>SOLUTION: When positive or negative surge voltage is applied to a pad 14, a PMOS or an NMOS diode of a protective circuit 13 is turned on and the surge current is discharged to a power supply side or a ground side. Moreover, partial surge current flows into a substrate 11 through the protective circuit 13. This current will flow into the internal circuit 12 from the inside of the substrate 11 whose depth is deeper than a predetermined depth from a lower layer of the protective circuit 13 of the substrate 11. Since an insulation layer 16 is formed in a part used as a current path of this surge current between the protective circuit 13 and the internal circuit 12, the insulation layer 16 prevents the surge current from flowing into the internal circuit 12. Therefore, malfunction of the internal circuit 12 is eliminated. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
