====== LED ======

{{mcmaster:unknown:lampwin-led-12v:blue_cf50x.jpg?300}}

[[mcmaster:unknown:lampwin-led-12v]]

[[mcmaster:apa:apa102c]]

[[mcmaster:szledcolor:sk6812b]]

[[mcmaster:unknown:btf-ws2812b]]

[[mcmaster:led-color:apa102-2020]]

https://www.youtube.com/watch?v=a2IY89FAjZE

https://www.richis-lab.de/Opto03.htm

https://www.richis-lab.de/Opto06.htm

https://www.eevblog.com/forum/projects/optoelectronics-die-pictures/

Open questions:
  - Why do red LEDs look so different than green / blue?
    - DONE, see below
  - Size comparison in various modules?
    - WIP below
  - Wire bonding unusual? Doesn't look like ball or bond
    - Its standard ball bonding, except the ball is on the controller. Wedge was terminated on the LED instead of the package
  - What is the hexfet like pattern?


^ Vendor  ^ Product          ^ Output  ^ Die area\\ (k um2,\\ m mm2))  ^ Notes                                 ^
|         | btf-ws2812b      | Green   | 39.4                          | [[mcmaster:unknown:btf-ws2812b]]      |
|         | btf-ws2812b      | Red     | 19.6                          | [[mcmaster:unknown:btf-ws2812b]]      |
|         | btf-ws2812b      | Blue    | 33.6                          | [[mcmaster:unknown:btf-ws2812b]]      |
|         | lampwin-led-12v  | Red     | 28.0                          | [[mcmaster:unknown:lampwin-led-12v]]  |
|         | apa102c          | Blue    | 36.8                          | [[mcmaster:apa:apa102c]]              |

"Red is usually some kind of GaAs and so a vertical structure. Green and blue are GaN and so more lateral. Ok, not really lateral but the substrate is not conducting..."


===== Red LED =====

{{:mcmaster:led-color:apa102-2020:roi1.jpg?300|}}

{{:mcmaster:unknown:btf-ws2812b:middle-red_mz_mit20x.jpg?300|}}

{{:mcmaster:apa:apa102c:led_3.jpg?300}}

{{:mcmaster:szledcolor:sk6812b:package_3x.jpg?300}}

===== Imaging =====

Notes:
  - Coverslip (with oil, not water) made images much better for packaged LEDs with rough surface (see [[mcmaster:led-color:apa102-2020]])
  - Infrared produced better images than optical for milky fill (see [[mcmaster:apa:apa102c]])