Lumileds website shows a new 1mm² LED.
- 1.38x1.38 mm package, very flat at 0.25 mm height
- 2700K-6500K with CRI80, 90
- 4 K/W thermal resistance
- rated for max 700 mA, 135 °C junction temperature
- no DTP pad
- I fail to find anyone selling them yet
Overall it seems largely inferior to Luxeon CZ White (which is 1mm² as well) except for curiously high efficiency.
Luxeon CSP HL1 CRI90 4000K delivers 104 lm at 350 mA with 2.8V, 102 lm/W.
Luxeon CZ CRI90 4000K delivers 89 lm at 350 mA with 2.75V, 92 lm/W.
And smaller package might allow some dense arrays, similar to E21 quadtrics.