How do filament LED bulbs work, looking very similar to incandescent bulbs?
These LEDs are not a single radial die, they are made with a transparent substrate with many LED dies in series (probably 25)  placed on it. The whole thing is then coated in phosphor. The light isn't completely uniform but it's good enough.

There's a spec sheet here: http://www.runlite.cn/en/product-detail-145.html