I'm attempting to design and make a Keyboard PCB and have stumbled onto a question I can't seem to find online (probably because I'm not searching for the right thing/lack of info)
When routing decoupling capacitors in parallel you do not place them next to one another, correct?
There should be one right next to every VCC pin?
Best Answer
Normally power supply bypass and signal filter caps get as close to the MCU body as possible. While the Vcc trace looks good the GND pads are linked with skinny traces that form a line from a via. If at all possible this GND should be a wide copper pour with many via's to a common ground plane.
As it is drawn the inductance will be high, thus noise on Vcc will be high at that location. Try to fatten the GND trace and see if extra via's can be inserted there. The many capacitors are good but not much use if not tied to ground plane in many places, for what little board space you have. When designing boards power and ground planes come first, then HF and high-impedance traces.
The bypass capacitors should be distributed so each Vcc pin has one next to it that has a short path to the ground plane.