41–50 of 87 posts
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And they suck to do manually. I started this morning off by hand-stuffing some PC boards with (among other parts) 19x 0402 resistors per board. There was a reason I did it before I had any coffee!
They aren't too hard with paste and an oven/hot air.
I'm surprised by how manual the whole process is. I think labour is so expensive in the west that any manufacturing of small low value items is incredibly highly automated (see youtube for lots of videos of how huge automated production lines work). There's no way you could employ someone to manually bond 80 LEDs a minute in the west and still have a competitive product.
I don't envy the eyesight of the worker that has to look through a microscope their entire shift, this was sad to read.
This is clearly an old process - when was the last time you saw a 7-segment display, or those big red round thru-hole LEDs, outside of hobby electronics? I'd be very curious to see how this process differs from the high-power lighting LED manufacturing process (e.g. CREE), which is a more modern technology by several decades. I would guess there is much more of the automation people are expecting...
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A 6" wafer will also have lots of dies on the edge that don't pass automatic testing. Don't forget that most devices are located near the edge. Secondly, upgrading your Fab to switch your process to larger wafer size has a 10-figure $ price tag. It's not trivial for digital, let alone opto electronics. LEDs are special in that they deviate severely from the standard mos process. When Monsanto first produced them they…
> A 6" wafer will also have lots of dies on the edge that don't pass automatic testing. Don't forget that most devices are located near the edge. I don't understand this. Given a fixed size die, the number of dies near the edge would go up linearly as the wafer size goes up. The number of interior dies would go up quadratically.
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For people who don't know 0402 is: > 0402 (1005 metric): 1.0 mm × 0.5 mm (0.039 in × 0.020 in).
And they suck to do manually. I started this morning off by hand-stuffing some PC boards with (among other parts) 19x 0402 resistors per board. There was a reason I did it before I had any coffee!
The pick and place machine needed blank strip of about ten components (just for lead-in on the cassete).
Transfering components from one tape to another was really annoying. And one of the bosses just did not understand that the fractions of a penny saved were obliterated by time wasted moving components over.
And until you've had to do something like that you can't really understand the benefit of $60 Swedish tweezers.
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A 6" wafer will also have lots of dies on the edge that don't pass automatic testing. Don't forget that most devices are located near the edge. Secondly, upgrading your Fab to switch your process to larger wafer size has a 10-figure $ price tag. It's not trivial for digital, let alone opto electronics. LEDs are special in that they deviate severely from the standard mos process. When Monsanto first produced them they…
> A 6" wafer will also have lots of dies on the edge that don't pass automatic testing. Don't forget that most devices are located near the edge. I don't understand this. Given a fixed size die, the number of dies near the edge would go up linearly as the wafer size goes up. The number of interior dies would go up quadratically.
I could do this in my basement! Years ago I answered a "for sale" newspaper ad for used office desks and some test equipment. I showed up at the address and it was a small dingy old building and most of the employees seemed to be 55+ year-old women. When I asked what they did and was told they made diodes, you could have knocked me over with a feather. Like he did, I assumed that all electronics parts manufacturing w…
I wouldn't make leds at home, but that's because of the chemistry, not because it can't be done...
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I don't envy the eyesight of the worker that has to look through a microscope their entire shift, this was sad to read.
We should make a raspberry powered microscope that can project onto a 22" HD display. It would be awesome if Lytro had a realtime USB version of their camera.