Bjt npn base collector junction breakdown

[SpartanG345]

When the NPN is in the forward active mode

The base emitter junction is forward biased and the base collector junction is reverse biased.
But isn't it possible for the base collector junction to break down? Or do we assume it never breaks down?

Also does anyone know any good water analogies that explain BJT's? I found some using google but they seem complicated.

I found this site http://www.satcure-focus.com/tutor/page4.htm
the 1st analogy doesn't seem to work that well when you think about which junctions are reversed and forward biased, but the second analogy seem ok - the one with the pools of water and the base acting as a catalyst to start the water moving

 

[reddvoid]

its possible that CB junction breaks down if u increase CB bias voltage . . .
usually collector base junction ll be biased below breakdown

 

[jsgruszynski]

When the NPN is in the forward active mode

The base emitter junction is forward biased and the base collector junction is reverse biased.
But isn't it possible for the base collector junction to break down? Or do we assume it never breaks down?

Also does anyone know any good water analogies that explain BJT's? I found some using google but they seem complicated.

I found this site http://www.satcure-focus.com/tutor/page4.htm
the 1st analogy doesn't seem to work that well when you think about which junctions are reversed and forward biased, but the second analogy seem ok - the one with the pools of water and the base acting as a catalyst to start the water moving

Yes. Vceo is actually Vbc junction breakdown plus a diode drop with Vbe.