| 摘要 |
PURPOSE:To improve the surge withstand voltage by bypassing surge voltage to a P-N junction diode of a deep junction by a method wherein the titled device is so constructed that an SBD as a clamping diode and the P-N junction diode of a lower breakdown voltage than that of this SBD are connected in parallel. CONSTITUTION:A P<+> type layer 12 contacting a GND side aluminum electrode 2 and an N<+> tupe layer 6 is provided in an N-type epitaxial layer 4. The P-N junction diode 13 of a lower breakdown voltage than that of said SBD 3 is formed of these N<+> type layer 6 and P<+> type layer 12 by controlling the P<+> type impurity concentration, and an input side SBD 3 and said diode 13 are parallel-connected between an input side aluminum electrode 1 and the GND side electrode 2. Therefore, it is possible to set the breadown voltage of said diode 13 at apporx. 8V-20V by controlling the above-mentioned impurity concentration. On the other hand, the breakdown voltage of the SBD 3 is approx. 25-30V, accordingly, when a positive surge voltage is impressed on said aluminum electrode 1, the most part of the surge current flows to said diode 13 and does not flow to the SBD 3. |
