击穿电压

击穿电压，是使某一绝缘介质在一段时间内成为导体所需加入的电压的最低值。当加于某一绝缘介质的电压足够高时，这时该绝缘介质便会发生电击穿，使电流可以通过。

绝缘介质的击穿电压

一股突发的电流可以永久地转变固态绝缘体中的分子结构，从而于物质中产生一道较易导电的路径。而一种绝缘体的击穿电压并不是绝对数值，而是通过统计得出的约数。因此，人们经常会取一个比击穿电压低的值来确保绝缘体被击穿的概率在安全范围之内。^[1]

击穿电压有两种量度方法，分别是交流电的击穿电压和冲击击穿电压。交流电会采用家用交流电的频率（多数为50Hz或60Hz）。冲击击穿电压是模仿绝缘被雷电击中时的情况，波幅会在1.2微秒内达至90%，在50微秒后会降至50%。^[2]此外，ASTM为击穿电压的试验提供两种技术标准：ASTM D1816和ASTM D3300。^[3]

在标准条件下，气体为绝缘性非常高的物料，需要非常高的电压才可击穿（如闪电）。气体的击穿电压由帕邢定律决定。而局部真空可降低击穿电压：^[4]^[5]^[6]

$V_{\mathrm {b} }={\frac {Bpd}{\ln Apd-\ln(\ln(1+{\frac {1}{\gamma _{\mathrm {se} }}}))}}$

其中 $V_{\mathrm {b} }$ 为直流电的击穿电压。 $A$ 和 $B$ 是取决于周边空气的常数数值, $p$ 代表周围空气的压强。 $d$ 是电极的距离。 $\gamma _{\mathrm {se} }$ 是二次电子发射（英语：Secondary emission）系数。^[7]

此特性可应用于微处理器之中，但亦能造成电器的短路^[8]。

二极管的击穿电压

二极管的击穿电压是指二极管反向导电的最小反向电压。反向电压可以击穿二极管，但如电流不大，反向导电是不会对二极管造成伤害的。事实上，齐纳二极管就是利用击穿效应穏定电压。

另见

雪崩击穿

参考

[1]
Relationship between Electrode Surface Roughness and Impulse Breakdown Voltage in Vacuum Gap of Cu and Cu-Cr Electrodes, Shinji Sato and Kenichi Koyama, Mitsubishi Electric Corporation, Advanced Technology R & D Center, 8-1-1 Tsukaguchi-Honmachi, Amagasaki-City, Hyogo 661-8661, Japan
[2]
Emelyanov, A.A., Izv. Vyssh. Uchebn. Zaved., Fiz., 1989, no. 4, p. 103.
[3]
Kalyatskii, I.I., Kassirov, G.M., and Smirnov, G.V., Prib. Tekh. Eksp., 1974, no. 4, p. 84.
[4]
G. Cuttone, C. Marchetta, L. Torrisi, G. Della Mea, A. Quaranta, V. Rigato and S. Zandolin, Surface Treatment of HV Electrodes for Superconducting Cyclotron Beam Extraction, IEEE. Trans. DEI, Vol. 4, pp. 218<223, 1997.
[5]
H. Moscicka-Grzesiak, H. Gruszka and M. Stroinski,‘‘Influence of Electrode Curvature on Predischarge Phenomena and Electric Strength at 50 Hz of a Vacuum
[6]
R. V. Latham, High Voltage Vacuum Insulation: Basic concepts and technological practice, Academic Press, London, 1995.
[7]
Yemelyanov, A.A., Kalyatskiy, I.I., Kassirov, G.M., and Smirnov, G.V., Abstracts of Papers, Proc. VII ISDEIV, Novosibirsk, 1976, p. 130.
[8]
Stefanov, L.S., Tekhnika vysokikh napryazhenii (High-Voltage Engineering), Leningrad: Energiya, 1967.

[1] [1]
Relationship between Electrode Surface Roughness and Impulse Breakdown Voltage in Vacuum Gap of Cu and Cu-Cr Electrodes, Shinji Sato and Kenichi Koyama, Mitsubishi Electric Corporation, Advanced Technology R & D Center, 8-1-1 Tsukaguchi-Honmachi, Amagasaki-City, Hyogo 661-8661, Japan

[2] [2]
Emelyanov, A.A., Izv. Vyssh. Uchebn. Zaved., Fiz., 1989, no. 4, p. 103.

[3] [3]
Kalyatskii, I.I., Kassirov, G.M., and Smirnov, G.V., Prib. Tekh. Eksp., 1974, no. 4, p. 84.

[4] [4]
G. Cuttone, C. Marchetta, L. Torrisi, G. Della Mea, A. Quaranta, V. Rigato and S. Zandolin, Surface Treatment of HV Electrodes for Superconducting Cyclotron Beam Extraction, IEEE. Trans. DEI, Vol. 4, pp. 218<223, 1997.

[5] [5]
H. Moscicka-Grzesiak, H. Gruszka and M. Stroinski,‘‘Influence of Electrode Curvature on Predischarge Phenomena and Electric Strength at 50 Hz of a Vacuum

[6] [6]
R. V. Latham, High Voltage Vacuum Insulation: Basic concepts and technological practice, Academic Press, London, 1995.

[7] [7]
Yemelyanov, A.A., Kalyatskiy, I.I., Kassirov, G.M., and Smirnov, G.V., Abstracts of Papers, Proc. VII ISDEIV, Novosibirsk, 1976, p. 130.

[8] [8]
Stefanov, L.S., Tekhnika vysokikh napryazhenii (High-Voltage Engineering), Leningrad: Energiya, 1967.

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