[HN Gopher] Semiconductors are more than just processors and GPUs
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Semiconductors are more than just processors and GPUs
Author : robertelder
Score : 120 points
Date : 2022-03-17 14:33 UTC (8 hours ago)
(HTM) web link (blog.robertelder.org)
(TXT) w3m dump (blog.robertelder.org)
| NikolaNovak wrote:
| I used to be a professional computer geek on weekdays and
| professional photographer on weekends; and 20 years on, it still
| blows my mind the similarities between the materials and
| manufacturing of the CPU doing heavy work in my laptop and the
| sensor gathering pixels in my camera :O
| genericone wrote:
| Transistors!
|
| E.g. EPROM (memory type chip) is typically deleted by shining a
| uv light on the actual silicon die, through a uv transparent
| quartz window in the final packaged chip.
|
| edit: fixed EEPROM -> EPROM
| analognoise wrote:
| That's not an EEPROM. That's an EPROM. The first E in EEPROM
| is ELECTRONIC - i.e. you use a voltage (or a control word) to
| indicate that you would like to erase the device.
|
| Also, EPROMs are extremely vintage. They were replaced by
| EEPROMs - the first of which came out in 1977. That's an...
| extremely vintage example.
| genericone wrote:
| Fixed
|
| And thanks for the info, I don't have direct experience
| dealing with EPROM and I had conflated EEPROM and EPROM
| together in my mind, but a quick google search quickly
| reveals my inadequate knowledge, which has now been
| updated, even if only good enough for trivia.
| dragontamer wrote:
| > Also, EPROMs are extremely vintage. They were replaced by
| EEPROMs - the first of which came out in 1977. That's an...
| extremely vintage example.
|
| IIRC, EPROMs were still cheaper than EEPROMs for many
| years. EPROMs probably were sold in commercial quantities
| well into the 80s, and maybe used in the 90s.
|
| EPROMs were erased by just throwing them into a UV-bin and
| blasting them with UV light. In contrast, EEPROMs needed
| transistors inside to handle the erasing cycle.
|
| Finally, EPROM's last stand was as a low-cost one-time-
| programmable ROM (aka: PROM). All you had to do was make
| the same chip except without the expensive "window" (that'd
| normally receive UV-light for erasure).
| babagabooj wrote:
| True. I was there. So were you, I assume. The previous
| poster was most likely speculating.
| analognoise wrote:
| No, I know they cost less for a while, but the 90's were
| 30 years ago.
|
| That's vintage, isn't it? In the 90's, stuff from the
| 60's was 'vintage'. By 2022... the 90's are vintage?
| AnimalMuppet wrote:
| We look back on the 60s with nostalgia. The 90s? Not so
| much. I think that colors our definition of what is
| "vintage".
| dragontamer wrote:
| Nah, I'm once removed.
|
| I had professors who were active during the time and gave
| me the rundown. I have touched EPROMs and all that good
| stuff, still part of the labs at my college and my
| professor liked talking about "the good ol days". But
| I've never in fact used them in any practical manner.
| lb1lf wrote:
| Studying EE in the late nineties, I can remember coming
| across EPROM microcontrollers a few times, but definitely
| not in new projects.
|
| IIRC, students recently graduated when I was doing my
| freshman year had used them for projects in their
| freshman year, but not since - so they were probably
| commonplace until 1990 or so. At least in Trondheim,
| Norway.
| jjoonathan wrote:
| I just flashed (literally, shined UV light through the
| window) and reprogrammed a few EPROMs on a pair of HP
| 83623a signal generators yesterday to facilitate moving a
| module from one, where we didn't need it, to another,
| where we did.
|
| Industrial equipment moves at a different pace, and in
| these days of 10x price jumps and "52 week" lead times,
| sometimes dusty relics from the 80s wind up being
| relevant in 2022!
| mywittyname wrote:
| Hence, why we "flash" certain components.
| moltke wrote:
| I read somewhere that some people used EPROMs and decaped Ram
| chips as digitizers for early computers.
| 01100011 wrote:
| https://hackaday.com/2014/04/05/taking-pictures-with-a-
| dram-...
|
| Yeah I remember a friend of mine back around '90 wanted to
| try it out. I can't remember if it was using DRAM or EPROM
| memory though. I want to say it was called 'ramra' or
| 'ramera'.
| blueflow wrote:
| Fun fact: Solar cells and the LEDs are the same element.
|
| If you wire up a solar cell like an LED, it glows dimly in
| infrared. QA uses this to diagnose dysfunctional wafers.
| reportingsjr wrote:
| Yep! This is why solar panels typically have another diode
| wired in series with them, so they don't draw/waste power and
| emit light at night!
|
| In the solar world they call it a blocking diode.
| kken wrote:
| No, there is no series diode. There is an antiparallel diode
| to prevent solar cells from turning current into heat when
| they are shadowed.
| CamperBob2 wrote:
| Well, almost anything will glow dimly (or brightly) in infrared
| if you shove enough electrons through it.
| maxbaines wrote:
| That's fun and super interesting, going to read more on it.
| altcognito wrote:
| Hey, Electroboom just covered this:
|
| https://www.youtube.com/watch?v=l2y-w9aS98k&t=617s
| Unklejoe wrote:
| Does the same go for Peltier plates and thermocouples?
| jbay808 wrote:
| Yes, thermocouples can work as heat pumps, and Peltier
| elements can work as thermocouples.
| deelowe wrote:
| Many electronics work that way. Motors can also generate
| electricity. Inductors can create or sense magnetic fields.
| Resistance is generally temperature dependent. Etc.
| jbay808 wrote:
| Almost any high-efficiency energy transformation is
| reversible, in fact!
| petschge wrote:
| Everything is as temperature sensor. Some elements also
| measure other signals.
| user_7832 wrote:
| Just made be realize, when you cook, the food is basically
| a temperature sensor. (Burnt) Toast is a great example.
| parenthesis wrote:
| You can use headphones as a microphone, or a (dynamic)
| microphone as a loudspeaker.
| ______-_-______ wrote:
| This is my favorite one. Being on stage and hearing music
| come out of your mic is a hell of a trip.
| tomn wrote:
| Here's a video of a circuit I made which flashes an LED, using
| only power collected by the LED:
|
| https://youtube.com/watch?v=BM7VDOoFIWI
|
| The LED is the component on the left; there's a very dim flash
| (pretty much just the black die turning red) at around 11s,
| then every few seconds.
|
| I can't remember exactly how it works... I think there's two
| capacitors charged up to the voltage of the LED in parallel
| through high-value resistors, and a circuit that shorts the +ve
| of one to the +ve of the other to put them in parallel.
|
| It only just works at a very specific light level. IIRC some of
| the transistors are used as very low leakage diodes rather than
| transistors, as the regular diodes I had we're too leaky.
| blueflow wrote:
| Now this is the most impressive thing i've seen today!
| Especially because its made out of discrete components.
| Kudos.
| tomn wrote:
| Thanks! I'm not sure what integrated components you could
| use for this, as anything useful would probably use more
| current than the LED can provide.
| mrtksn wrote:
| Cool, it's a self powered light meter. The more light there's
| in the environment the more frequent the blink. Maybe can be
| adjusted to have less frequent, shorter lasting but more
| powerful flash!
| magicalhippo wrote:
| Steve Mould had a video[1] about this a couple of years ago
| where he shows a small solar panel lighting up.
|
| [1]: https://www.youtube.com/watch?v=6WGKz2sUa0w
| agumonkey wrote:
| Is it possible to have a light / emw battery ?
| nofunsir wrote:
| If you shine a light at a mirror, then quickly point the
| mirror at another mirror, it will keep a dark room lit for
| a couple hours.
| SECProto wrote:
| Speed of light is fast, even if possible you'd be looking
| at a lot of conversion losses. It'd be like trying to use a
| wire as a battery because power has to travel from one end
| to the other
| thehappypm wrote:
| I've heard of materials that can slow down the speed of
| light propagation. Imagine you can slow the speed of
| light to a crawl. You shine a huge amount of light into
| this material, which has a mirror on the other side.
| Before your light arrives back at the source, swap it for
| a mirror. You've now got a huge amount of light energy
| trapped.
| swamp40 wrote:
| I spent most of the day yesterday chasing down crosses for
| P-Channel FETs.
|
| They are all GONE. No stock of anything (except the crappy ones,
| super-tiny packages, high Vgs(th) or high Rds(on) and other
| leftovers).
|
| I've never seen anything like this, it's kind of frightening.
| Like walking into a grocery store and seeing the aisles all EMPTY
| except for a few scraps.
|
| I don't even know where they all went. It's not like you need a
| TSMC slot to make a FET.
|
| And _whatever_ you look up, Chinese brokers have 10K-50K pieces
| of them for $25 each. Don 't know what to think of that, either.
| nickff wrote:
| Switched-mode power supplies (SMPS) are eating components at an
| alarming rate. The increase in high-efficiency DC and battery-
| powered products has really changed that market.
| [deleted]
| bluesquared wrote:
| It's my current living nightmare. Endless treadmill of:
|
| 1. Our contract manufacturer calls in a panic no longer able to
| obtain/was shorted on a shipment of part XYZ. XYZ is
| increasingly becoming random "jellybean" parts like MOSFETS,
| oscillators, to slightly-more-complicated but not "fancy" stuff
| like serial transceivers, USB stuff, NOR flash, load switches.
| TI is the bane of my existence currently.
|
| 2. Search for a drop-in or near drop-in replacement. There are
| none, because that's what everyone's doing.
|
| 3. Search for alternative designs. Maybe the component is in
| distributor's stock (Digikey, Mouser, Newark, etc), maybe it's
| not.
|
| 4. Test the alternative design. By the time I receive parts,
| prototype, test, guess what? Can't get those parts anymore. Go
| back to step #2.
|
| 5. Fall behind on all of my other NPD responsibilities. Stress,
| burnout, acceptance. Lament not going into another engineering
| field. Feel bad about my midwest metro area compensation in
| comparison to a bunch of Silicon Valley SWEs on website.
|
| 6. GOTO #1
| swamp40 wrote:
| Your OODA loop is way too long. We buy ALL the parts
| immediately, within 10 minutes of finding something. If they
| don't work, it's a loss.
|
| On new designs, I find a part in stock, we order ALL we need
| for the next year, and THEN I make a footprint and put it in
| the design. For EVERY SINGLE PART. Starting with the IC's. It
| actually works quite nicely once you get used to it.
| Obviously, there are some losses there too - just the cost of
| doing business in these crazy times.
| InitialLastName wrote:
| Next-level business plan: become a chip reseller for all
| the parts you didn't use. The prices are only going up.
| bluesquared wrote:
| Wish my slow corporate behemoth would support this, but
| they are the opposite of agile.
|
| It's also gotten to the point where there doesn't exist
| enough stock in distribution to buy a year's worth. And I'm
| not talking high volume, maybe 1k/year to 50k/year.
| Distributors are constantly decommitting from orders,
| broker stock is drying up, etc
| swamp40 wrote:
| It is surprising how easily companies will fund this
| change in buying habits when the entire company's
| existence depends on it. The CEO needs to have a come-to-
| Jesus moment though.
|
| We've spent several hundred thousand at "Win Source"
| broker in China, and haven't had a problem yet (knock on
| wood). We X-ray and test to verify though.
|
| Mostly, Chinese brokers are a den of thieves/a pool of
| sharks. If they can counterfeit it, they do. Use a credit
| card to help with clawing your money back in case of
| fraud. And never ever buy IC's from Amazon or Ebay. Those
| are ALL fake.
| amelius wrote:
| That doesn't work for new designs when the parts are simply
| not available.
| Gracana wrote:
| > increasingly becoming random "jellybean" parts
|
| I can't even get cables anymore. Or connectors. It's an
| insane situation, and the company I work for isn't built to
| manage this level of churn in our products. How do you
| support customers when equipment BOMs change every week? We
| just can't keep up.
| extrapickles wrote:
| I'm involved with pneumatic connector manufacturing, and we
| had trouble for awhile getting raw aluminum at any price to
| make them. At one point we had to buy 3" aluminum bar and
| use our lathe to turn it down to the size we actually
| needed (mostly a mix of 2" and 2.5") causing a insane
| amount of aluminum and time to be wasted (yes the scrap is
| recycled, but its worth 1/10 of it in bar form). During
| this it was tempting to tell customers placing orders that
| if they want their parts faster than 3 months, they need to
| send us raw aluminum so we can actually make their order.
|
| For some of the other "jelly bean" parts we need (o-rings,
| snap rings, etc) we are looking at making them in-house,
| but both the raw materials and machinery to make them are
| not possible to get. We could spend the next few months
| making our own machines to fabricate them, but without
| being able to source steel and various rubbers any more
| reliably than the finished goods, there isn't much point.
|
| At this point, its tempting to try and raise capital to
| start mining and smelting aluminum, steel and buy an oil
| well and small refinery so we can ensure we have the
| materials needed to keep production smooth.
| daniel-cussen wrote:
| Companies used to do that before the leveraged-buyout /
| MBA / private-equity ridiculousness started. I
| think...Youngstown Tube Co had its own mines, called
| "captive mines" dedicated just to making metal for them.
| That's where captive insurance got its name.
| sitzkrieg wrote:
| ive been trying to find some power mosfets to certain specs for
| a BOM for.. over a year!
| zargon wrote:
| It's not TSMC capacity that's the problem. It's the large nodes
| that make everything _except_ cutting-edge processors. Nobody
| builds a new large-node fab, but demand for large node
| components keeps rising.
| jjoonathan wrote:
| lol did that one Renesas fab with the fire make literally
| every damn semiconductor in the world that wasn't a CPU or
| GPU?
| swamp40 wrote:
| Sure seems like it. I was hoping to see if anyone knew the
| root of the problem, but if they do they aren't talking.
| Denvercoder9 wrote:
| A big part of it is increased demand _caused by the
| disruptions themself_ : a lot of companies are now
| stocking to have enough to run production for the whole
| year, while otherwise they'd order just-in-time. That
| causes further reduced availability, which causes more
| companies to stock up, repeat ad infinitum.
| nwellinghoff wrote:
| You nailed it. Most chips you use everyday come from the
| large node fabs. Maybe we should build some more.
| mywittyname wrote:
| Demand for semiconductors only recently exploded. In 2016,
| annual growth suddenly tripled for a few years. It's hard to
| know if this rate of growth is sustainable, or if it will
| fall back to "normal" again soon.
| madengr wrote:
| I had your exact same problem a few weeks ago trying to get
| P-channel FETs and ended up with the SI2301CDS-T1-E3 which
| Mouser has just 143 left (which you can't believe).
|
| Same with USB-UART bridges; zip, nada, nothing. I found some
| Cypress parts a few weeks ago, and I should consider myself
| lucky.
|
| I won't order PCB until I have all reels of parts on my desk.
| ComputerCat wrote:
| Yup, same where I work. We are chasing down the smallest
| components too.
| geph2021 wrote:
| shouldn't these shortages lead to older equipment/processes
| being dusted off and brought back online?
|
| 7nm or whatever state-of-the art processes may be important for
| certain latest electronics, but I'm guessing there are many
| components that could use 10 year-old or more semiconductor
| fabrication processes.
| dragontamer wrote:
| Good overview, but he's missing one of the coolest applications
| of semiconductor / photolithography.
|
| MEMS. Micro-electromagnetic systems. The most common MEMS I can
| think of is the comb sensor, used for accelerometers in all of
| your cell phones.
|
| https://www.memsjournal.com/2010/12/motion-sensing-in-the-ip...
|
| The MEMS sensor for an accelerometer is quite simple. Take the
| nearest comb and smack it against a desk: you'll notice that the
| comb vibrates in one direction. Now hook up two combs and
| interleave their teeth together so that they're barely touching.
| When they touch, an electrical signal is sent through them to
| sense when they touch.
|
| Add differently sized teeth, the larger the spacing the more
| acceleration is needed before they activate. (EDIT: Looks like
| the iPhone MEMS uses capacitance... similar concept though, the
| capacitance changes based off of how far away these teeth are
| from each other and you can measure that using college-level
| electronics)
|
| Finally, have these teeth rotated in all directions, so that you
| can sense all the directions in one little device.
|
| --------
|
| MEMS are about using the physical properties of object, but just
| making these small physical objects really, really, really tiny
| thanks to the magic of photolithography.
|
| You can see this literal comb structure by looking at any
| accelerometer under a microscope:
| https://memsjournal.typepad.com/.a/6a00d8345225f869e20148c70...
|
| ------
|
| If the accelerometer is too difficult for you to understand, the
| "beginner MEMS" is gears.
|
| https://www.sandia.gov/app/uploads/sites/145/2021/11/1-1.jpg
|
| You can make any shape you want with modern chip-making tools.
| The "shape" most people want is a transistor (gate, drain,
| source). But in many ways, a teeny-tiny gear is simpler to think
| about.
|
| The practical applications of micro-scale MEMS (gears, combs,
| springs, etc. etc. ) is somehow harder to think about than
| computers, so there aren't very many practical MEMS around. But
| still, practical MEMS help remind us that all of these chip-
| making tools exist in the real, physical world. Albeit at a very
| small scale.
| _moof wrote:
| Microelectro _mechanical_ systems.
| alted wrote:
| MEMS are awesome! Here are some other MEMS devices:
|
| - hard drive read/write heads (the platters are debatable)
|
| - inkjet printer nozzles (this is why making a DIY inkjet
| printer is nontrivial)
|
| - air pressure sensors (e.g., for car tires)
|
| - precise frequency filters for smartphone wireless
| communication
|
| - oscillators (https://news.ycombinator.com/item?id=18340693)
|
| - very tiny microphones for smartphones (speakers are harder)
|
| - Digital Micromirror Devices (DMDs): arrays of tiny mirrors
| used in most projectors
|
| - microfluidics ("lab-on-a-chip" stuff for fast disease
| testing, DNA sequencing, cell manipulation, etc)
|
| And a couple other semiconductor applications:
|
| - LCD/LED screens (monitors, phones, laptops, etc) (these are
| made on a glass surface instead of a silicon wafer but use the
| same basic manufacturing techniques)
|
| - laser diodes (laser pointers, CD / Blu-ray players)
|
| - many quantum computers
| rcxdude wrote:
| Capacitive sensing is the norm for consumer accelerometers: you
| generally don't want surfaces making contact and especially
| sliding past each other in MEMS in practical applications
| because the surfaces will tend to stick to each other or wear
| extremely quickly (MEMS gears are a neat trick but you won't
| find them in any product using MEMS because they last a few
| minutes of operation at best).
| mardifoufs wrote:
| Here's a cool, pretty in depth 15 minutes video on MEMS:
|
| https://youtu.be/iPGpoUN29zk
| HPsquared wrote:
| Someone needs to make Charles Babbage's Difference Engine in
| MEMS. A total misuse of technology, but a fun exercise.
| philipkglass wrote:
| CPUs and GPUs account for more dollars spent than solar cells,
| but solar cells account for most area/mass of semiconductor
| devices made today.
|
| A gigawatt of solar cells represents about 5 square kilometers of
| silicon wafers at 20% light conversion efficiency. The world
| installed 183 gigawatts of solar PV in 2021, almost all of it
| based on silicon wafers:
|
| https://www.pv-magazine.com/2022/02/01/bloombergnef-says-glo...
|
| That's in the neighborhood of 915 square kilometers of wafers.
|
| Silicon for solar has risen meteorically over the past 20 years.
|
| https://www.pv-magazine.com/2021/10/26/whats-next-for-polysi...
|
| _Until the early 2000s, demand for polysilicon (often simply
| referred to as "poly") was dominated by the semiconductor
| industry, which required a fairly steady 20,000 to 25,000 metric
| tons (MT) per year. But semiconductor demand for poly was quickly
| outpaced by PV as the solar industry began to grow rapidly, from
| a rounding error at the turn of the millennium to almost half of
| global polysilicon demand by the middle of the decade._
|
| ...
|
| _By the end of 2013, the manufacturing cost of polysilicon had
| tumbled to below $20 /kg among industry leaders. Meanwhile,
| capacity had grown from less than 50,000 MT per year in 2007 to
| over 350,000 MT per year by 2013._
|
| Polysilicon capacity at the end of 2021 was in the neighborhood
| of 700,000 metric tons, with more big expansions on the way. The
| extra 350,000 metric tons added since 2013 is almost entirely for
| solar.
| hateful wrote:
| I almost always think of all the things on breadboards (e.g. in
| the second picture on the page). But it's probably because of all
| the games I played had those kinds of things in their technology
| thumbnails. Or maybe it was because I was alive when Radioshack
| existed.
|
| most recently: https://dyson-sphere-
| program.fandom.com/wiki/Microcrystallin...
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