Oh boy... I got 3 bond wires... not again

[D-Dog]

After reading some interesting discussion in another thread on the bond wires seen in all LED's, I have decided to start a thread on just the issue to hopefully divert some traffic away from ^^^ thread to this one.


*Why do some LED's have more bond wires than others

*Why are some bond wires yellow while others are bare metal(gold color)

*How many bond wires to multi-die emitters have since I don't have any to look at

Feel free to discuss P4 vs Q2 or... that must be a Q* or above because it has 4, etc here because I want this to be a learning thread about a rather "different" topic

 

[Illum]

*Why do some LED's have more bond wires than others

As LEDs advance, more bond wires are used to allow higher current drivers. Wires have resistance, the thinner they are the higher resistance they have when driven at around 1A, but in the LED manufacturing process the bond wires can't be any bigger...so more is added to compensate

*Why are some bond wires yellow while others are bare metal(gold color)

they are all bare metal, 24K gold IIRC. All the CREE dies are made in USA, but the LED fabrication location may vary. US fabricated CREEs have phosphorus layered evenly throughout under the LED dome, which gives the wires a yellowish appearance. the Asian fabricated dies only have phosphor in the emitter region and not the substrate, which looks silver and the bond wires retain their respective gold color.
SSCs are the same, they use CREE dies but are installed by SSC in their version of LEDs, and if you look closely SSCs only apply phosphor around the emitter region too, leaving golden bond wires clearly visible underneath the dome.

Heres an example of US made CREEs, picture order left to right by bin [P4, Q4, Q5]

Source: Fenix P1-CE, Fenix L0D-CE Q4, Fenix H50-Q5

Heres an example of an Asian made CREE

Source: Muyshondt Aeon

*How many bond wires to multi-die emitters have since I don't have any to look at

usually they would have just two, one for the anode and the other cathode. They will come in pairs. SMJLEDs come in 6 or 8 [3-4 individual dies], Super Flux [square] LEDs may have 6, 8, or even 10 bond wires]

Heres a couple examples since you don't have any to look at
SMJLED, 8 [count them] eight bond wires tells you theres 4 separate dies in the LED

Source: Macroshot of a 2-cell PR SMJLED

High Flux LED, 6 bond wires indicate theres 3 separate dies per LED

Source: Macroshot of a fenix lightbar disassembled

unknown high powered LED 3W WahWang [:thanks: chimo]

quite amazing...12 bond wires

 

[Jarl]

P7's and MC-E's have over 20 each, though I can't recall the exact number. Due to the independently addressable nature of the MC-E's dies, it has more bond wires than the P7. Neither has more than 30, though.

 

[Illum]

P7s have 17 [see thread], the MC-E dunno...you can count them here if you want, it has ~20 because there are bus bars built inside the LED

 

[DM51]

Good idea for a thread, and very good macro photos from Illum too. Let's hope there's a better discussion here than the rather aimless one in the other thread.

 

[Carpenter]

Thank you Illum for the tutorial. I've never gotten that close to an emitter before to see bond wires.

I believe in the saying that "you learn something everyday", and since it's before 10AM, I can relax the rest of the day.

 

[Illum]

well, apparently this is what my cameras best for...nothing else has it taken that was really impressive [Canon SD630]
I started a thread in the beginning of the year about LED types, theres more examples of other multi-die LED pics submitted by other users there [link]


glad I could help :wave:

 

[Black Rose]

Over in that other thread there was a comment about the P4.

Some are saying that all P4s have 3 bond wires, others seem to imply that P4s could have 3 or 4. I lost track of things when the thread mutated.

I posted that I have a light (Romisen RC-C3) with a 4 bond wire P4 (light was sold as having aP4),
but now I'm wondering if it might be a Q2. I doubt it's a Q4; it is definitely not a Q5.

The LED in the light is silver backed.

Is there a definitive answer to the question about the number of bond wires on a P4?

EDIT: Forgot to indicate I am referring to Cree P4s, not Seoul P4s.

 

[Illum]

Some are saying that all P4s have 3 bond wires, others seem to imply that P4s could have 3 or 4. I lost track of things when the thread mutated.

well...it depends on how good your eyes are and what degree from the plane your looking the LED from..
according to jarhead [before his retirement] the P4 he received have 3 bond wires plus something distinct on the corner
[source: here]




I'm not sure where the 4 part comes in, it may be the bond wire way out on the side...but I do notice one thing all SSCs have in common, there will always be one bond wire leading to the substrate, not to the LED, unlike those on the CREE emitters

According to jarhead's review of the first SSC terralux module to come about, specifically TerraLUX MiniStar 5 Model TLE-6EX
Another view of the P4
[Source: here]http://www.molalla.net/~leeper/terralux.htm]


I don't see the 4th, either that or its below the dome in or near the same area as the first pic

just to add to the mystery


**Note the CREE dies in the SSCs, one would wonder how SSCs manage to overtake the authentic CREE in performance when theres so much gunk over the dies :thinking:

 

[chimo]

unknown high powered LED

quite amazing...12 bond wires

That's a 3W WahWang. You can do a search on the board to find more info on it.

 

[Black Rose]

Clarification...in my previous post I was referring to Cree P4s

BTW, really nice macro shots I_T_N.

 

[Christoph]

 

[Illum]

Clarification...in my previous post I was referring to Cree P4s

nevermind then..um...
um...
um... :thinking:
ahh, I see the confusion now:green:
I was told long ago that CREE P4s only have 3 bond wires, and examples are almost always LEDs of US origin [all yellow], but recently theres an addition of asian CREEs that have 4 bond wires but are either stated as P4s explicitly...or the light output isn't up to par with the Qs and leaders the users to think they are Ps.
example here
The thing is though, frankly it should not matter whether there are one more or one less bond wires, its like a complaining to ACE hardware about their floor brushes have 10 less bristols than Home depots at the same price, do you see the difference while brushing? no? then put a sock in it

we simply cannot tell the difference by looking at the die plus theres an array of other variances not considered: LED/driver assembly: thermal bottlenecks?
driver efficiency?
driver current?
etc.
All we know up to now is that somewhere between Ps and Qs one extra bond wire was added, and it appears to be consistent between the Qs and the Rs that have 4 bond wires. And DonShock did a very good summary of it here:

When answering a question on CPF earlier today, I got to taking a close look at the Cree LEDs is several of my modifications. And I think I figured out a way to tell the difference between the P3, P4, and Q2 bins based on looking at differences in the die inself. Before I continue to describe the differences, I need to mention that this assumes the LEDs I recieved from the various vendors were of the bins promised. The multiple Crees of a single order of each type shown were consistant in their appearances and the differences between types as noted. So I am fairly confidant that these features are representative of the different bins. But these are just my obsevations, so take them for what they are worth. Maybe somebody with access to more LEDs or from more verifiable sources can confirm this independantly.
Cree P3:
3 bond wires, "tab" on one end only, small "sub-square" at corner of end

Cree P4:
3 bond wires, "tab" on both ends, small "sub-square" at center of one end

Cree Q2:
4 bond wires, "tab" on both ends, small "sub-square" at center of one end


I hope this helps when you need to figure out the bin of an unknown Cree LED. If I get some other bins and can figure out some distinguishing characteristics, I'll add them to this thread.

 

[DM51]

It is interesting to see the tiny Chip Weevil larvae on the surface of the LED's dome in that photo. Modern dome materials are impregnated with new silicone-based insecticides which are making them more impermeable to the weevils - manufacturers are reporting some successes with this technique.

 

[Black Rose]

I fell for that the first time....

 

[Illum]

<Almost drifted the thread into another debate on the crisis of chip weevils >
post edited

 

[Black Rose]

I was told long ago that CREE P4s only have 3 bond wires, and examples are almost always LEDs of US origin [all yellow], but recently theres an addition of asian CREEs that have 4 bond wires but are either stated as P4s explicitly...or the light output isn't up to par with the Qs and leaders the users to think they are Ps.
example here

Mine looks like that picture, just in a different light. Silver backed LED with 4 wires.

It's too bad Don's pictures are gone...would like to see what they were.

 

[Illum]

It's too bad Don's pictures are gone...would like to see what they were.

which thread are you referring to? I may have saved the thread

 

[Black Rose]

You quoted Don's identification of the various Cree's above.

All I see are red X's where the picture were.

 

[Illum]

You quoted Don's identification of the various Cree's above.

All I see are red X's where the picture were.

yeah, I saw that when I went to find the URL
I thought you meant Don as Don "Mcgizmo" McLeish

heres my saved copy btw, I have it archived 08042007
the pictures are direct links, meaning they cannot be enlarged








due to pictures and the archiving notes I've stopped saving whole threads, media and all as of 04092008, believe it or not just selecting threads of personal interest managed to put me through at least 5GBs of space and about 50,000 files...luckily I have this one saved