What happens when a diode breaks down?

Hi,

What is meant, in physics terms, that a "diode breakdown" occurs? I noticed that, according to the formulas, this takes place at higher voltages than avalanch and Zenner breakdown. So what are the physics behind it?


Thanks in advance,

Sharas

Diode breakdown

Temperature increases because charge carriers increases and a fisical damage occours.

Re: Diode breakdown

**broken link removed**

Regards,
IanP

Re: Diode breakdown

Thanks, but I still don't understand:
1) Why is heat destructive?
2) What does it mean "destructive" ? The diode will act like a "short" or "open" ?

Diode breakdown

actual diode consume power and generate heat.
both in open state because of leakage current,
and short satete because forward voltage drop.
when produced heat go to higher value than max. specifiead value (refer to diode manufacturer data sheet) this heat may destroy diode.

Regards,
Davood.

Re: Diode breakdown

HI DEAR,

Breakdown Voltage (Insulator) = The minimum voltage that makes an insulator react as a conductor.

Breakdown Voltage (diode) = The minimum reverse voltage to make the diode conduct in reverse

Breakdown Voltage (diode)[

Is a parameter of a diode that defines the largest reverse voltage potential that can be applied without causing an exponential increase in the current in the diode. As long as the current is limited, exceeding the breakdown voltage of a diode does no harm to the diode. In fact, Zener diodes are essentially just heavily doped normal diodes that exploit the breakdown voltage of a diode to provide regulation of voltage levels.

Re: Diode breakdown

Thanks Vicky for your crystal clear explenation. I finally understand!!

Diode breakdown

diode breakdown is mainly due to increase in energy and mobility of the electrons ..which leads to collision and rupture of bond

Re: Diode breakdown

this is taken from a web page..this might answer ur qn clearly

when the diode was reverse-biased (p-region negative with respect to the n-region) that the only current which flows is the reverse saturation current, resulting from the few thermally generated minority carriers which can fall down (or up) the barrier.If we make the reverse bias even greater, the same current flows, but the carriers pick up more energy as they fall down the (now larger) junction potential. As they do this, it is possible for them to pick up so much energy, that when they collide with a lattice site, they create an additional electron-hole pair through a process called impact ionization.When this occurs, we now have current consisting of two electrons and one hole. These additional carriers can themselves collide and generate additional electron hole pairs as well. The current now consists of five electrons and two holes. This process is called avalanche multiplication.because we start with one carrier, and through a succession of impacts create more and more current. This process can in fact run away, much like an avalanche on a snowy mountain side, in a process called avalanche breakdown.