Placement of Capacitors C1 and C2
Thought for 8 sec
Yes — I’d add stitching vias, plus a few power/thermal vias, but keep them intentional.
Recommended vias for this board:
-
GND stitching vias
- Add around the board perimeter every ~5–10 mm.
- Add near the USB-C shield/GND, ESP32 GND pins, MAX98357A GND/thermal pad, and speaker return/current path.
- Purpose: tie GND layers together, improve return paths, reduce EMI.
-
ESP32 RF keepout caution
- Do not place stitching vias inside or directly in front of the ESP32 antenna keepout.
- A GND via fence can be useful near the module body/edge, but keep it outside Espressif’s antenna keepout.
-
MAX98357A thermal/GND vias
- Add several small vias from the exposed/thermal pad area to the internal/bottom GND copper.
- Purpose: thermal dissipation and lower-impedance ground for the class-D amp.
-
3V3 power vias
- If Mid-Layer 2 is your 3V3 plane, add multiple 3V3 vias near:
- AMS1117 VOUT/TAB
- ESP32 3V3 pin
- MAX98357A VDD pins
- local decoupling caps
- Purpose: avoid relying on one via for ESP32 Wi-Fi/audio current bursts.
- If Mid-Layer 2 is your 3V3 plane, add multiple 3V3 vias near:
-
USB return vias
- Add GND vias near the USB-C connector and near where D+/D− enter the ESP32 area.
- Do not add random vias in the D+/D− pair unless needed; keep USB routing clean and symmetric.
-
Button/NeoPixel vias
- No special via strategy needed; normal signal vias are fine.
- For the WS2812, add a nearby GND via and local decoupling path if it uses 5V.
Use normal through-hole vias unless you have a strong reason for microvias/blind vias. For this board, standard through vias are enough and much cheaper/manufacturable.
Add vias and verify
Add stitching vias
Add power vias
Add thermal vias
Run via review
