The definition of breakdown voltage
The breaddown voltage is toward insulator and dielectric.
If you know some basic electronic theory, ionization and conduction take place in a gas or vapour.
So, as strong currents through insulator or dielectric may be ruptured.
Breakdown Voltage of insulator
This part we go deep in breakdown voltage of insulator.
The breakdown voltage of an insulator is the minimum voltage that causes a portion of an insulator to become electrically conductive.
Breakdown Voltage of diodes
There were some different Breakdown Voltage between diodes with insulator.
For diodes, the breakdown voltage is the minimum reverse voltage that makes the diodes conduct in reverse.
Addition PCBA definition
A metal alloy (solder) which melts above 450℃ but below metals being joined.
Solder that spans across two or more conductors causing an electrical short-circuit.