Now that I created 3D printed shims for the LEDs to nestle under, I was really curious which LED configuration would have the best & brightest light distribution. So I threw together a test board.
Here's the board. Each one encapsulates both LEDs and resistors under the switch. Starting from left to right:
- Two 0603 LEDs on the outside with their 0603 resistors in the center.
- 0805 LED in the center.
- 0603 LED in the center, resistor perpendicular.
- 0603 LED in the center, lengthwise.
- 0603 LED in the center, widthwise.
Which one do you think was the best?
- I think the right three were equal in distribution and had a nice glow.
- The 0805 seemed to be too bright, and centered in one place (not evenly diffused).
- Using 2 LEDs provided excellent distribution of light around the switch, but was brighter than necessary.
For me, the winners (by a small margin), were the right three (single 0603 LED).
But, to be honest, it wasn't a fair fight. The brightness of the 0805 LED is spec'd at 150mcd while 0603 is a mere 60mcd. So I'm confident that if you brought the brightness of the 0805 down, it would perform as well as the others.