Cree emitters look different, need clarification.

I routinely purchase Cree R2 drop ins from DX (the guys at work like them for surefire 6p's). Upon inspecting each drop in (with approximately 20 or so received within the last year) I have observed that there are two variations of the "alleged" Cree R2's that I recieve (I am referring to the yellow die inside the LED, please disregard the different mounting boards, these are pics I have borrowed). Some that I receive look like this:

NOTE THE BROWN/ORANGE IN COLOR COATING BEHIND/AROUND THE YELLOW DIE.


The other emitters I receive look like this:

NOTE THE ABSENCE OF THE BROWN/ORANGE IN COLOR COATING BEHIND/AROUND THE YELLOW DIE.


Does the brown/orange coating have something to do with different tint? I know its a crap shoot as to whether I receive genuine r2 bins from DX (as I suspect the differences here could possibly indicate some are r2 bins and some arent), but for the price the guys at work dont really care. Can anyone shed some light on this for me? I did a search of the forums on this subject to no avail. Thanks in advance.

cree switched from using the EZ1000 dice to smaller EZ900 dice. the copper "frame" around the EZ900 die is from the common substrate used for the larger EZ1000 dice as well.

Thanks for the clarification. Are there any advantages for either of the two? I assume the slightly smaller die is possibly a bit better of a thrower?

Found this topic has already been discussed here:

https://www.candlepowerforums.com/threads/234821

Mods please feel free to delete!

the smaller die is indeed slightly better at throwing.