Author Topic: How does a genuine WS2812 look?  (Read 955 times)

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Offline mattselectronicsTopic starter

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How does a genuine WS2812 look?
« on: August 05, 2020, 08:51:09 pm »
Hello,
I was wondering which of my WS2812 based devices use genuine chips. I got most of them from Aliexpress, so I expect some fakes. I put all of them under the microscope and had a look. I was a bit surprised, that all of them were different from each other.
Does anybody know which one (if any) is the genuine WS2812, which ones are cheap fakes and which might be SK6812?
I read that the really cheap copies use aluminum bond wires which are much less reliable. Judging from the color of the bond wires I believe one of them has this kind.
 

Offline OM222O

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Re: How does a genuine WS2812 look?
« Reply #1 on: August 05, 2020, 09:01:46 pm »
WS2812 is the chip inside the LED. You can see it as the black square / rectangle inside the LED. Any manufafturer that makes LEDs is likely to have a different setup so no surprises there.  If you want to check if the IC is geniune, you can't do much besides X ray imaging or decaping the LEDs. Not worth the trouble.
 

Offline mattselectronicsTopic starter

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Re: How does a genuine WS2812 look?
« Reply #2 on: August 05, 2020, 09:04:01 pm »
I just realized, that all Leds, exept number 4, have only 4 pins.
The WS2812 is supposed to have 6 pins...
The SK6812 has 4 pins, but which one would be genuine there?
 

Offline OM222O

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Re: How does a genuine WS2812 look?
« Reply #3 on: August 05, 2020, 09:07:02 pm »
Some of those dies have more than 6 pins, I'm not sure what you're talking about. Also why do you care so much if you bought them off of aliexpress? If you want genuine parts then order from mouser/digikey/farnell, etc.
 

Offline wraper

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Re: How does a genuine WS2812 look?
« Reply #4 on: August 05, 2020, 09:10:10 pm »
WS2812 is the chip inside the LED. You can see it as the black square / rectangle inside the LED. Any manufafturer that makes LEDs is likely to have a different setup so no surprises there.  If you want to check if the IC is geniune, you can't do much besides X ray imaging or decaping the LEDs. Not worth the trouble.
Why would you need to decap or X-ray it when you clearly can see the IC inside? It will not give any additional information. If you have an original IC to compare, it's pretty easy.
 

Offline mattselectronicsTopic starter

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Re: How does a genuine WS2812 look?
« Reply #5 on: August 05, 2020, 09:11:34 pm »
WS2812 is the chip inside the LED. You can see it as the black square / rectangle inside the LED. Any manufafturer that makes LEDs is likely to have a different setup so no surprises there.  If you want to check if the IC is geniune, you can't do much besides X ray imaging or decaping the LEDs. Not worth the trouble.

Well, there is only the WS2812 from Worldsemi which is genuine, everything else is a clone.
I would expect the genuine LEDs to look all the same (OK there may be different revisions, but not as many).
You can see the bare die and the bonding through the window, so no need to x-ray it.
The die is completely deifferent on all the LEDs I have. It's not as visible in the pictures, because my camera is not the best.
 

Offline wraper

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Re: How does a genuine WS2812 look?
« Reply #6 on: August 05, 2020, 09:14:14 pm »
Also WS2812 is not an IC which is sold separately for other companies to use in their LEDs AFAIK. If trusting the datasheet, it should look like this. LED #4 has exactly the same package and LED die locations but IC looks different. Other LEDs are completely different.

« Last Edit: August 05, 2020, 09:18:13 pm by wraper »
 

Offline mattselectronicsTopic starter

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Re: How does a genuine WS2812 look?
« Reply #7 on: August 05, 2020, 09:27:36 pm »
I found this picture here: https://www.adafruit.com/product/3094
I guess adafruit buys from a "good" manufacturer/supplier, so we could use this as reference for SK6812.
The base metal looks like in number 1, but the die and the bonding is a bit different. I think this could be due to a different revision.
 

Offline wraper

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Re: How does a genuine WS2812 look?
« Reply #8 on: August 05, 2020, 09:39:39 pm »
Adafruit says they will ship either SK6812 or WS2812 based LED. WS2812B has 4 pins BTW, the same as SK6812.
 

Offline mattselectronicsTopic starter

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Re: How does a genuine WS2812 look?
« Reply #9 on: August 05, 2020, 09:53:57 pm »
Adafruit says they will ship either SK6812 or WS2812 based LED. WS2812B has 4 pins BTW, the same as SK6812.

You are right, I was reading just the headline, but under Technical Details they state that both can be shipped.

I found the attached Picture on the pololu homepage: https://www.pololu.com/product/2527
Looks exactly like the adafruit one. They state it is a SK6812.
 

Offline Hiemal

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Re: How does a genuine WS2812 look?
« Reply #10 on: August 07, 2020, 12:56:24 am »
Supposedly another way to tell if you have counterfeit LED's is to take a sharpie marker and dab a little bit of ink just outside of the potting compound... if the ink seeps in under the potting compound then they're fake. Something about counterfeit LED's not being potted properly is the reason why.

I don't know how much credence this method actually has, though.  :-//
 


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