Hi, I had been trying to decouple the power supply of a prototype circuit with200mhz+ fast pulses and precision timers, with a smd capacitor on a double sided pcb, but found there was still measurable noise on the gnd side of the capacitor due to stray inductance. the back side of the pcb is undisturbed ground plane with smaler gnd planes on the top side conected with vias. I didnt realy have room to route a better gnd conection for another capacitor and rather than put the capacitor on the back and disturb the gnd plane I had an inspiration and drilled a 1 mm hole and found a 10nf smd capacitor fitted through the hole perfectly, the end caps were flush on either side of the pcb and cld be soldered ok and the chips power pin put on top of the buried capacitor, therefore taking up very little space.
I had one go short circuit some time later (and it took a while to find as I had forgoten it was even there!) but then I find smd components can get upset quite quickly when reworking a prototype many times, the capacitor cheked out ok when I removed it, although it seemed low in value but increased when pressure applied, i find other capacitors can also fail simlarlarly varying capacitance with a smal flex of the pcb after being re soldered a few times.
A small array of through hole capacitors at various points solved the noise problem. I remember old tv tuners used to have square block ceramic wich went through a slot in the pcb, I was wondering if this is still considered ...