Edit:Warning: there's an error in one of my assumptions in this question, which more or less invalidates it. See Tom Carpenters answer.
I'1m designing a switched mode power supply, and of course need various capacitors in the design.
For instance, to spare the mains from all the noise from the switching action, I'm thinking about building an LC filter with a 3uF capacitor.
So now I've been trying to source 3uF capacitors. Of course it's not difficult at all to source a 3uF 450V capacitor. Polypropylene caps seem to be suitable.
But the cost of a capacitor capable of handling at worst 1A of ripple current, is signficiant (say 5 euro). See for example.
However, 1uF ceramics can be had almost for free, see for instance. 2000 caps for ~13 euro.
If I put the 1uF 100V caps 15 in series, 3 in parallell, I need 45 caps. This will cost approximately 0.3 euro.
Of course I'll need some resistors to balance the caps. Placing the caps at a reasonable distance I calculate that they would all fit within a 12.5mm x 12.5mm box, which means they take up a fraction of the space of the Epcos one.
One possible problem could be that DC bias reduces capacitance of ceramics. But for my application I need approximately 400V, so with 15 in series the 100V 0603 caps are loaded only marginally, and should retain most of their 1uF capacitance.
I'm not really considering doing this, but would it work? Or will the 0.3A+ ripple current kill the little 0603:s?