LED Package Type, Help Identifying - Page 1
Forum section: electronics / projects

author: SeoulBigChris
author_rank: Regular Contributor
timestamp: April 12, 2023, 05:20:49 am
content: I'm working with some LED's provided by a customer in a package I'm not familiar with. Searching around, this Lumex LED is one of a few legitimate data sheets I can find that documents this general package typehttps://www.mouser.com/datasheet/2/244/SML-LXL8047UVC-1176710.pdf.Here are the characteristics I've been able to figure out so far:High(-ish) power LED (the particular one I'm using is 5W, but there are also 1W in the same package)It seems to fall in the category of "color lighting" rather than "ordinary" LEDsCalled 8 mm "dome" style, but the actual LED lens is around 5 to 6 mm diaIt is an SMD package, in what I'd call a gull-wing arrangementLooks like a 4-pin rectangular pattern with pins 2 and 4 removed (offset 2-pin gull wing)Seems to be associated with Lumileds (Philips/Agilent) 2006 obsolete Luxeon K2 packageI have enough information to proceed with a PCB layout, but I'm still curious. Is this style just an informally agreed upon "loose standard" among the LED manufacturers? Or is there a formal package type defined somewhere, like JEDEC, EIA/TIA, ANSI, etc.?(I can't post a picture, for some reason. No matter how small I make it, it returns an error saying the image size is not less than 5000 KB, even though it is well under that limit).

author: SeoulBigChris
author_rank: Regular Contributor
timestamp: April 12, 2023, 05:21:53 am
content: Here is a typical image of this package type.

author: floobydust
author_rank: Super Contributor
timestamp: April 12, 2023, 06:16:44 am
content: I know it as an old LED package Lumileds Luxeon Star, Cree had it too, that got copied en masse in china and are prolific as a big low cost, low tech package.Called "bead LED" they are offered in 1W, 3W, 5W ratings. There are many lenses available as well.The LED underbelly has a thermal pad which cannot be overlooked. It requires to be soldered to heat dissipating pad. I think the 3W, 5W needs a Mcore PC board, FR-4 is not enough.More modern high power LED packages are commonplace nowadays.

author: james_s
author_rank: Super Contributor
timestamp: April 12, 2023, 06:22:12 am
content: That's a standard Chinese power LED, they've been around forever, some of the first high power LEDs I bought back around 2009 looked like that. I still see them often in cheap LED grow lights and such. I often see thermal paste used on the pad rather than solder, typically aluminum core board but you can use regular FR4 for the 1W variety.

author: SeoulBigChris
author_rank: Regular Contributor
timestamp: April 12, 2023, 11:33:37 pm
content: I wet down the trail of “star” package also. I wasn’t sure, but I kind of concluded that star package was the tiny star-shaped module itself, and not the actual LED package. I found many star shaped boards that contained and LED, or group of LEDs, of different package types. But I could easily be wrong about that.

author: james_s
author_rank: Super Contributor
timestamp: April 13, 2023, 01:38:46 am
content: I'm a little fuzzy on the terminology but the package is common none the less. You can even buy little round aluminum core boards to mount them on. The quality of LEDs found in that package style is highly variable, but even the cheap generic ones will last pretty well if you under-run them. I used them to retrofit the license plate lights in one of my cars about 7 years ago and there's a nightlight with one at my mom's that's been running for more than a decade and still looks fine. I think it's only running about 30mA though.

author: GLouie
author_rank: Regular Contributor
timestamp: April 13, 2023, 01:40:31 am
content: I knew it as the original Lumileds (Philips) Luxeon series of early high power LEDS. The star would be when the LED emitter was pre-attached to a metal-core PCB (MCPCB) of various sizes. Indeed, they first had 1 watt, then 3 and 5W. There were competitors using the same pads (Seoul Semi). I think the K2 came afterwards.I don't know about a standard for the package. Manufacturers seemed to copy pad layout specs a lot, so you could just substitute. Anecdotally, I seldom see this old package, modern emitters tend to come on a ceramic substrate and are reflow soldered, no plastic body.Here's a couple of the data sheets from the day (around 2002).