How to identify Cree Q5

[richdsu]

Can somebody help / enlighten me :

How to identify a Cree Emitter Q5 from Q4 , Q2 ???

 

[markfinn]

I recall that 4sevens mentioned in a thread a few days ago the following (original quote):

"Here some neat insights to Fenix's source of LED's... Fenix puts out so much
volume that it affects the industry's view on high powered LED's.
Lumileds reps and Cree reps often visit the factory offering competitive
deals on their top of the line products. I can tell you that the non special
edition LED's are often quietly fitted with top of the line bins simply because
they can't get enough of random bins. I wouldn't be surprised if some of
the stock stuff have Q5's. I peered into the head of a non special edition
Fenix from a recent shipment and I see 4 bond wires instead of 3. They
started doing the 4 bond wires when they hit Q bins. The extra bond wire drops the Vf significantly."

So it seems there is a way of at least identifying Qs and non-Qs by taking a look at the bonding wires.
Maybe an expert can tell more, I would also like to know more details here.
Regards,
Markus

 

[jirik_cz]

you should check this topic, especially post 4 and 6.
http://candlepowerforums.com/vb/showthread.php?t=171118

it appears that you can't determine Cree bin by number of bond wires.

 

[evan9162]

I peered into the head of a non special edition
Fenix from a recent shipment and I see 4 bond wires instead of 3. They
started doing the 4 bond wires when they hit Q bins. The extra bond wire drops the Vf significantly."

Which also isn't true. P4 bin XR-Es with 3 bond wires regularly have a lower Vf than Q bins. The extra bond wire only modestly affects Vf at higher currents. The Vf is primarily dependent on the individual die its self. People are reporting that Q5 binned XR-Es tend to have a signifitantly higher Vf than previous bins.

 

[richdsu]

There must be some sort of electronic circuit that we can rigged it up to verify the Vf corresponding to the Q2 Q4 Q5 specs..... wondering companies like Fenix how do they verify the cree emitters if they accidentally mixed up ?

When the R bins going to launch soon, how the manufacturer is going to convinced us that what we are buying are genuine R bins??? Me think they should like many other electronic components be laser-marked with some codes for identification/ authentication. :thinking: :thinking: :thinking:

 

[leprechaun414]

 

[evan9162]

There must be some sort of electronic circuit that we can rigged it up to verify the Vf corresponding to the Q2 Q4 Q5 specs.....

There isn't. It's easy enough to test the Vf (you just need a 350mA constant current source). However, this will tell you nothing about the output bin of the LED under test.

We've only seen a tendency for Q5 emitters to have a higher Vf. This is only meaningful in comparing a large number of samples. This is meaningless when talking about individual samples. You cannot simply measure the Vf of a bunch of XR-Es, then proclaim that the ones with the higher Vf are the Q5s. Some Q5s will have lower Vf, and some higher. Vf is not a meaningful characteristic in determining the luminous output of an LED.

The only way to determine Q5s from others is to test the luminous flux of the LED, which is (surprise) exactly how they are binned as a Q5 in the first place.