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How LEDs Are Made
An anonymous reader writes "The SparkFun team took a tour of a factory in China that manufactures LEDs. They took lots of pictures showing the parts that go into the LEDs, the machines used to build them, and the people operating the machines. There's a surprising amount of manual labor involved with making LEDs. Quoting: 'As shipped on the paper sheets, the LED dies are too close together to manipulate. There is a mechanical machine ... that spreads the dies out and sticks them to a film of weak adhesive. This film is suspended above the lead frames ... Using a microscope, the worker manually aligns the die, and, with a pair of tweezers, pokes the die down into the lead frame. The adhesive in the lead frame wins (is more sticky), and the worker quickly moves to the next die. We were told they can align over 80 per minute or about 40,000 per day.'"
You have to expect that in a country where manual labor is cheap. In other countries, it makes more economic sense to automate or otherwise fix inefficiencies in the manufacturing process.
Any sufficiently unpopular but cohesive argument is indistinguishable from trolling.
The most striking thing to me about that .. article is that the factory was actually closed on a Saturday.
pneumatic, hydraulic, etc...
Don't complain about syntax, grammar, or spelling. There is no.hell like input on android.
I suspect this story may draw comments from people who know something about LED manufacturing. If so, I hope someone can answer this question. I noticed that panels of LEDs, such as used for traffic lights or stage lights, are composed of 200 individual LEDs. So the process is:
Cut one LED panel apart, into hundreds of LED cores.
Glue hundreds of leads to the hundreds of fresh cut cores.
Align hundreds of cores into hundreds of little molds.
Inject resin into hundreds of little modes.
Assemble all of the hundreds of resin-covered LEDs back into a panel again.
Why not this?:
Attach ONE set of leads to the LED silicon panel.
Dip the whole dang panel in resin.
They are also using some biological machines, apparently.
Ezekiel 23:20
beta sucks. When will it be canceled?
They probably are doing 57K a day, but for political reasons only advertise 40K a day.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
Understandable. They probably don't let their employees get on Sashdot. Or it would be 1200 per day.
Have gnu, will travel.
Machines may be more efficient, but they would need to be manufactured and run on coal electricity. Perhaps we should encourage handmade electronics for the time being.
My interpretation is as follows. The equipment shown is stuff that could have existed in the 1960s. In the West, that's pretty much how machines looked like in the 60s. The #1 company that made and still makes these machines is Kulicke & Soffa.
http://www.kns.com/en-us/Pages...
China basically scoured North America for all the old machines they could find. Ribbon machines that make incandescent lightbulbs. Pick and place machines. Board plating shops. Wire and ball bonders.
All this stuff that used to the define the West's technological prowess. K&S is now based in Singapore.
https://www.youtube.com/watch?...
Oh, and if you want to see something fast and automatic, look up chip shooter on youtube...
Mostly random stuff.
https://www.youtube.com/watch?...
there you go, some closeups of some other junk being bonded.
Mostly random stuff.
Note: I am speaking as a material engineer who spent about 6 years in R&D for the 65W LED bulbs you can now buy at HomeDepot. The articled failed to mention the most important aspects of the LED manufacturing: wafering and the MOCVD that deposits the light emitting materials (the PN junction) onto the wafer. In short, the steps would include: 1) Crystal growth / wafering / surface prep; (make the wafer) 2) Nitrite epitaxial growth; (grow the light emitting part) 3) Wafer fabrication (cut big wafers down to die-sized chunks) 4) Packaging and testing (encapsulating the die) -- what the article was describing The article only touched upon the 4th step of LED manufacturing, and concidently, the most automated aspect of manufacturing, as well as the part that contains the least amount of patents / trade secrets. The first 3 steps were marginalized as "This is a sheet of LED dies. YunSun buys their dies from a high quality Taiwanese company". To my knowledge, there is no high quality manufacturer in Asia outside of Japan. Samsung makes a great quantity of ok stuff, and China / Taiwan makes a great quantity of shitty stuff that is ruining the entire high profit margin products. Also, all of the major manufacturers of LED dies dare not introduce step (2) and (3) into China / Taiwan due to IP issues. Wafering is important because larger wafer sizes (2in to 4in to 6in) means more dies per area. However, crystal quality becomes harder to control as sizes go up, especially for US-based LED manufacturers that is based on silicon carbide instead of sapphire. The real issue is with the MOCVD, the deposition technique that grows the PN junction which actually emits light. In the world of deposition, MOCVD is archaic voodoo magic and we spent a lot of time praying to deities of deposition that our process would repeat for more than a day. Fab is more systematic than epitaxial growth, and the real science here has to do with light extraction. Again, big money is spent on R&D here, and we dare not bring the manufacturing process to Asia (except for Japan).
Not just the production way is low-tech, this type of LED is depricated for everything but the cheapest crap available.
Modern LEDs are basically all SMD, the high power ones typically mounted on a solid metal core PCB. And those are acutally manufactured in a more modern type of way.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
...squinting at tweezers day-in and day-out for most of your life and the toll that would take on your eyes. It must be even harder for tall people with long arms.
I never did look into how LEDs are made (hey, I just buy and put them to use) and that it is a "cottage industry." And LEDs are made in open air facilities instead of clean rooms. I can start my own LED factory but unlike the author I don't have a basement.
mfwright@batnet.com
More liberal propaganda to justify our loss of lightbulb freedom
When I was last involved with lead it was treated as a hazardous material, gloves and a gas mask at the minimum were required when working with it, or around it.
Go to a foreign country, get invited to take a rare trip through a valuable suppliers factory.
This supplier carefully dresses up for his guests, and makes sure his factory is spotless for the important, honored visitors.
And you show up in a ratty t shirt and wtf are they,capri shorts?
Nothing like showing respect for your hosts. What did you bring as a gift, a used newspaper you read last week?
-Styopa
They were referring to "lead frames", the wire terminals and internal die supports used in a semiconductor package (before the plastic overmolding is done).
Nothing to do with the toxic heavy metal with the symbol Pb.
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I suppose that makes sense - if a CPU can have millions of transistors in less than one square inch, the wafer density is way to high to have only a few hundred diodes on a chip large enough to handle the heat. Unless of course much, much larger process sizes were much, much less expensive.
this is another factory with more automation.
https://www.youtube.com/watch?v=dDcMarYHknA
make light work!
Modest doubt is called the beacon of the wise. - William Shakespeare
Hate to tell you, K&S is not the leader in die bonding or wire bonding, but thats just from my observation in factories full of die bonders and wire bonders.
I design build and install backend semiconductor equipment, since the late 70's.
Back in the 1980's huge factories in Asia were installing the latest automated equipment. It was not unusual for us to install die bonders that were capable of 5k parts per hour per machine. In groups of 40 machines per device.
These were dedicated to a particular type of lead frame. But could mount multiple types of die. We had lines of 2N2222's at customers putting out over 20 million parts per week, all in a area the size of that room shown, including wire bonding. They had streamlined the whole process including injection molding, testing, and marking in a area only 5 times that room size. Before the automation there was 1000 girls per shift doing the same thing.
I was amazed that the Asian factories had such good automation compared to what I had see in factories here in the USA. But it was truly due to total volume. Here I NEVER saw a factory if the scale I would see there. Now I used to put this over to just labor, overhead cost etc in my mind back then. Later I would think it was due to regulation. Instead I now put it to foresight. They they knew if they could do it even 1/10 cent cheeper they would get the work. And if they got the work, it would never come back here to the USA. And they were right.
Led work is somewhat slower, especially those T1 frames they are using. They have to be handled vertically, and the spacing in between is large. So indexing time and centering of the cup takes a bit more work. Back when we did make machines for that product, the typical machine ran about 2K parts per hour. I am sure now, a bit faster indexing is possible. Thats why so many leds now are done on flat stock and molded and surface mounted, density and speed of manufacturing is much higher.
What they are showing is a cheep startup. Sales of led's by the container load are cheep, as it is a very stable process and anybody can do it. Where the problem comes in is manufacturing variables mostly in the wafer to have even appearing leds. Since the majority of leds are for human viewing, doing things like stop lights or where there are more than one led per product, we want them to appear the same, and look the same over time. So if you get led's from different lots they can appear to be different to the human eye. Especially if they are high output, as heat dissipation over time really degrades the device. That is also why they dont mount die directly to a PCB for stop lights. You can see if one die is different from the other, and while it is possible to adjust each die with a resistor, this adds another step, laser trimming of resistors using visual feedback. The cost of changing out a led made on a metal frame, and the cost of laser trimming is vast, when speed of manufacturing is involved. Much cheaper to just remove the leds and put another in, same for repair. If you pot a lens over a single pcb with multiple dies, it is no longer repairable.
State.
Mostly random stuff.
I never knew this style of LEDs were mostly made by hand.
I always assumed it was done by an automated assembly line, like how (mostly) CDs and DVDs are created on automated assembly lines.
Now would enjoy it, if someone could tour a LED light bulb factory, and share how those are made.
Uh, Linux geek since 1999.
hello...there is a reason buckets were invented...so slaves can pee whenever they need to at their station...
Sleep your way to a whiter smile...date a dentist!