You can find 0603 0.1uF ceramics with 50 volt ratings. OTOH, 0603 1.0uF
ceramics are very hard to find at over 16 volts.
Jim
True enough, but most digital (and many analog) bypass applications
these days are for 5V or less. Even some inexpensive microcontrollers
such as the 60MHz LPC210x series are now running at 1.8V nominal on
the core and 3.3V on the I/O, so you don't have to be working with
massive GHz CPUs to be using sub-2V supplies. That (ARM7TDMI-S) core
is only 0.32mm^2 if made with a 0.13u process.
It's not hard to find X7R ceramic 1uF in larger sizes rated at 50V
100V, which is fine for input power bypass caps on small ~1MHz SMPS
buck regulators. I expect availability to increase in the near term,
so they may be appropriate for new designs.
Best regards,
Spehro Pefhany