Physical size of old Ceramic cap vs new ones ?

[lordvader88]

I replaced an electro.cap backwards by accident, and when it blew up, it cracked a bit off an old 1960s ceramic cap.

The cap is about the size of a quarter (a coin), 100n 25V, it's across a 9V zener, part of a -12V series pass regulator, in a Tektronix 422

It should not get hot for any real reason, so can I just put in a little generic 100n ?

[james_s]

Generally that should be fine, parts have gotten much smaller over the years, not just caps. Do keep in mind that some types of ceramic capacitors lose a lot of capacitance when a DC voltage is present across them but that may not be an issue here.

[Berni]

Yep ceramic capacitor technology has come a long way.

Tho for very compact capacitors like having 10uF in 0603 size there can be some not so nice effects setting in. Such capacitors use more exotic ceramic materials that have crappy characteristics. One of those 10uF caps turns into only 5uF when the rated voltage is applied and they are highly piezoelectric. If you apply a few volts AC at a few KHz across it it can start beeping loud enough to be heard into the next room. Same goes in reverse, if you smack the PCB it can generate a lot of voltage across itself from the vibration.

But at capacitance as low as 100nF im sure anything is going to be fine as long as its not some tiny grain of salt sized capacitor.