Taiwanese mystery LED

jashhash

Enlightened
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Sep 12, 2004
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I've been ordering an LED unit from Taiwan for work and it has a surprisingly good result. I was doing a cross comparison between them and an XPG unit that I'm prototyping and based on a performance comparison it appears that these mystery LED's are getting at least 100 Lumens per Watt. Assuming that the Taiwan company who sells this to us gets a 50% mark up the cost per LED would have to be in the $1.00 - $1.25 range. The only problem is I just can't tell what they are or where to get them. This LED would be ideal for general lighting purposes because of its low cost and high efficiency. I was wondering if anyone here might be able to identify the LED based on this picture.

This is a picture of the unit:
LEDCloseUp.jpg
 
That creamy stuff seals the metal of the circuit board from the environment. The actual LED chip is square in shape with a little black tab on the corner.
 
if you could light one up at very low current, that would help. Doesn't look like generic white LEDs, since the dice are larger than usual
 
This LED would be ideal for general lighting purposes because of its low cost and high efficiency.

How about lifetime and dimming? I would not trust those without testing at least few hundred hours.. :candle:
 
The Nichia range including NJSW072 have black cathode marks like in the picture, but they have 2 marks not 1. Also their emitting area doesn't appear to be circular.
 
Sry about the long wait for reply. We have these LED's at work and I'm not able to light it up dimly to look at the die since they are connected to a driver. I could ask the board mounter where they got the LED's but it may be kind of rude to ask for their supplier. Well I can call them today and try.
 
Try taking a pic of them while lit. Most cameras can adjust enough to get a decent image.
 
There is really no way to know, even with a picture. There are several large and lots of small LED die suppliers in Taiwan, Korea, Japan and China. Many die from many firms are used in many package formats, openly and not that well traced.

The odds of identifying one of 50 or so die suppliers and 20 odd packaging suppliers is daunting. Even if you do manage to do it for this one supplied board part it does not mean they will have access to that same die quality in the future. Kind of a pain, isn't it.
 
I'm still awaiting reply back from the LED mfg for a spec sheet of the mystery LED. No guaranties for a response though so I cross my fingers.
 
There is really no way to know, even with a picture. There are several large and lots of small LED die suppliers in Taiwan, Korea, Japan and China. Many die from many firms are used in many package formats, openly and not that well traced.

The odds of identifying one of 50 or so die suppliers and 20 odd packaging suppliers is daunting. Even if you do manage to do it for this one supplied board part it does not mean they will have access to that same die quality in the future. Kind of a pain, isn't it.

If it is single die.... which is sort of looks like, and it is truly 100 lumens/watt (hard to tell with just your eye), then the number of die suppliers will be pretty small. That said, in volume, one can get Nichia's in this range for not much more than $1.00 and even Cree XP-E are between $1.25 and $1.50. It is not unusual for far east vendors to sell low volume at low prices in order to generate some volume.

Semiman
 
Sry about the long wait for reply. We have these LED's at work and I'm not able to light it up dimly to look at the die since they are connected to a driver. I could ask the board mounter where they got the LED's but it may be kind of rude to ask for their supplier. Well I can call them today and try.

not necessarily, part of product design and engineering requires you to understand the physical and electrical characteristics of certain LEDs in your possession prior to being able to integrate them into whatever design you have in mind. Finding these information is often proceeded by the location of its datasheet. The most common origin of datasheets is from their supplier.

I see no rudeness in requesting supplier information, since manufacturers often consume large quantities of LEDs from their suppliers anyway, there may be strong ties between their supplier and their own company. I'm sure some would agree that your request for their supplier hails you as a potential customer for future prospects, afteral... its good for business :naughty:
 
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