Why Are Circuits on Boards?

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Reddit Comments

Great pacing. I learned a lot, fast.

👍︎︎ 30 👤︎︎ u/iLikeOldTrees 📅︎︎ Feb 05 2021 🗫︎ replies

It's good! Those cyborg glasses are a bit districting, as are all those flappy hand movements. But the content is great!

👍︎︎ 23 👤︎︎ u/Nightlight10 📅︎︎ Feb 05 2021 🗫︎ replies

I read it as “why is citrus on boards” and thought he was smelling it in the thumbnail

👍︎︎ 9 👤︎︎ u/TheThingy 📅︎︎ Feb 05 2021 🗫︎ replies

Noice

👍︎︎ 5 👤︎︎ u/Bistromatic 📅︎︎ Feb 05 2021 🗫︎ replies

You sir are a good teacher!

👍︎︎ 5 👤︎︎ u/ZaurbekStark 📅︎︎ Feb 05 2021 🗫︎ replies

Does anyone else see Adam Sandler in the still shot? Lol Great technique, was easy to follow without any IT background.

👍︎︎ 5 👤︎︎ u/ITellMeSecretz 📅︎︎ Feb 05 2021 🗫︎ replies

Great, i learn alot.

👍︎︎ 4 👤︎︎ u/Momna211 📅︎︎ Feb 05 2021 🗫︎ replies

Around 5:20 did he beep out "retardant" as a joke?

👍︎︎ 2 👤︎︎ u/AdamsOnlinePersona 📅︎︎ Feb 06 2021 🗫︎ replies

Yeah, I found this channel a few months ago and it rocks. I didn't go very far into past posts, though. I hadn't caught this one. Nice!

👍︎︎ 1 👤︎︎ u/Turious 📅︎︎ Feb 05 2021 🗫︎ replies
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There's a component so useful, it's in every  single piece of electronics. It's so ingenious,   it's been almost unchanged since World War  II. It's so important that every electrical   engineer learns to design them. You won't find  this component anywhere on a board, because...   it IS the board! I'm Zack Freedman, welcome  to Voidstar Lab, and today we're asking a   big question about something that everyone takes  for granted - why are circuits on boards anyways? Every modern electronic device, whether  it's a nuclear-powered space probe from 1977   or a self-balancing rideable beer  cooler from 2020, has at least one   printed circuit board at the center. It's the  most ubiquitous electronic component of all.   It's the technology that literally  holds the world of electronics together,   the printed circuit board. You might have  noticed that electronic components have become   a liiiiittle more advanced over the last century.  This is a capacitor from the 1940s - it's made   of foil and paper soaked in electrolytes. This  is the modern version - it's made of metallized   film and a gel electrolyte. Electrolytes - they're  what electrons crave. This is Intel's cutting-edge   1971 processor that features a whopping 2,250  transistors. Here's their 2020 model with about   three and a half BILLION transistors. This is  a printed circuit board from the 1950s - it's   made of copper on fiberglass. This is a 2020  circuit board, made of... fiberglass and copper. Once upon a time, there were no boards at all.  Manufacturers glued or screwed components directly   to the device's chassis, and then soldered the  wires to each other. Point-to-point soldering   made early appliances possible, but it was crude.  That web of twisted leads was not a good use of   space. It took a lot of manual labor to assemble,  it made complex circuits diabolically snarly, and   it gave fork-wielding toddlers a buffet of options  to zap themselves into the shadow realm. Gosh! As time passed, devices grew more complicated  and wire wrapping was invented to cram more parts   into the same amount of space. Technicians  stuck the components through a perforated   wiring board - literally just a board with holes  - and they used a power drill to wrap little   wires around each of the leads. They routed the  wire where it had to go, wrapped the other end,   and bam! Connection made. It looks nice  and tight on top, but on the bottom... [Cliche screechy horror string music] This brings us to World War II. America had to  shove a ton of electronics into a bomb THIIIIIS   big. Wire wrapping and point-to-point soldering  were not only too bulky, they were far too   labor-intensive for wartime production. Instead,  the Army screen-printed metallic paint onto a pair   of ceramic discs and soldered parts in between  them. This didn't just speed up production - this   new so-called printed wiring board was more  compact, more durable, it was easier to repair,   and it was harder to short, and these are all  features that you want in a warhead. By 1943,   in the thick of World War II, the U. S. of A.  had covered the country in an entire industry   of board fabricators just to make more of  these fuzes. Anyways, a couple years passed,   America stuck 32 electronic detonators in a  different kind of bomb, and we ended World War II. As the war machine unwound, the birthplace of the  stuffed-crust pizza found itself dotted with a   network of large-scale circuit board manufacturers  who had just lost their biggest client. Soon,   cheap printed circuit boards were making their way  into industrial, and then consumer products, and   a lot of former professional wire wrappers were...  were checking the help-wanted ads. PCB's really   electrified the electronics industry. Before,  you needed an entire factory full of artisan   wire wrappers and professional solderers just  to manufacture a piece of electronics, but now,   all you needed was a stack of boards and a river  of solder. Companies could suddenly produce a   wider variety of products, pack them with even  more components, and sell them at even more   affordable prices. Parts manufacturing absolutely  exploded to keep up with this demand, which   enabled even more consumer products, and that  in turn begat even more demand and even cheaper   parts. The next thing you know, you're watching  YouTube in the bathroom and you forgot to wipe. Since 1943, electronics production has become  way cheaper, safer, easier, and sexier,   but at the end of the day, circuit boards are  basically the same today as they were back then.   They might be more angular and more green,  but a printed circuit board is still   a thin stiff board with copper printing...  for your circuits. Let's snoop around! These are the traces, which carry electric  current just like flat wires. This is a via,   a little tube-shaped wire that connects a trace  on top of the board with a trace on the bottom.   This is a through-hole pad and this is a surface  mount pad; components get soldered onto these   pads to connect them to the circuit. But the  board also physically carries the components,   too - soldering a component onto the  board makes a mechanical connection   as well as an electrical one. The board itself is  made of an insulating high-dielectric material.   That means it doesn't conduct current or allow  high-voltage arcs to punch holes through it. The   first commercial circuit boards were made  of cardboard hardened with phenolic resin;   it turns out that running electricity over  paper soaked in tree sap is actually a really   bad idea. Nowadays, we usually use fiberglass  because it's tougher and it's heat resistant.   In fact the most common material is called  FR4 - that's flame retar[REDACTED] type 4,   which actually extinguishes itself if it catches  fire. Fun fact: Nearly every modern circuit board   actually fluoresces green under a blacklight.  The manufacturer mixes a glow-in-the-dark dye   into the fiberglass so that assembly robots  called pick-and-place machines can easily see   the board. Pick-and-place machines are really  cool and they're going to get their own video,   and if you want to see that video - call to  action - subscribe and hit notifications. [Bling!] The board begins life as a sheet of copper clad  - that's a stiff backside with copper foil glued   to it that covers the entire board edge to edge.  The PCB fabricator, AKA the fab house, draws the   circuit onto the board using a chemical-proof  paint called resist. Then, the board is dunked   into etchant, which dissolves the exposed copper.  Only areas covered by resist stay on the board. A   technician washes the board off, drills holes for  the components, and bam! Printed circuit board. Back in the day, an engineer would literally  paint the traces, by hand, with a brush,   onto the screen used for printing. This is why  old-school circuit boards have those whimsical   curvy traces and those teardrop-shaped pads -  because those organic shapes are easier to paint.   Artwork for modern boards, with all the angles,  is generated by an EDA program - that's electrical   design assistance - instead of by a steady-handed  engineer. A photolithographic printer applies the   resist, and a computer controlled CNC mill, not a  grizzled chain-smoking machinist, drills holes and   mills slots. But what's really neat is that even  though the manufacturing has become a lot fancier,   modern PCB's are still like old school  PCB's - they're still thin, stiff cards,   they got copper printed on them, they got holes  drilled in them, and we stick stuff to the copper. Since World War II, we have made some  improvements. The most important is solder mask,   which is this enamel-like paint that protects  copper traces from corrosion and prevents stray   solder from shorting circuits. That was a tongue  twister! Most circuit boards are green because   they have green solder mask. It's... it's just...  it's just green paint. Isn't that a letdown?   On top of the solder mask, there's markings,  part numbers, etc. called an overlay; it's   screen-printed on to make life easier for jabronis  like us to hack stuff. One set of wires is nice,   but what if we need even more wires? Let's  double the fun by putting another set of traces,   mask, and overlay on the bottom side too!  Now we got ourselves a dual-layer board.   Need even moooore wires? Just laminate a  bunch of extra-thin boards together into   a Scooby-Doo sandwich and you got yourself a  multi-layer board! [Cartoonish munching noises] Most modern devices actually still use  double-layer boards because they're cheap,   but some PCB's, like the ones in computer  motherboards, can have more than 20 layers! So now we need to connect these layers of  traces together. Solder a wire from the top   to the bottom nah? Drill a hole and electroplate  it? Yeah. The same way that steel rusts, exposed   copper will corrode in air; we might as well  gold plate the entire board while we're at it!   I love goooooold! Finally, those big through-hole  components with those wires that have to be jammed   through holes? Yeah, they gotta go. We replaced  them with teeny-tiny surface-mount components   that use conductive pads on the ends. This  is called surface mount technology because   they're soldered directly to the surface  of the board as if the solder were glue.   They don't have wires that punch through the  board and get soldered on the other side. Manufacturers continued to make chips smaller  even as they crammed in more and more features.   Some parts now have so many signals and need so  many wires, they can't physically fit the pins, so   we've changed the connecting pins from metal tabs  around the edge of the chip into a grid of metal   balls on the bottom of the chip. These ball grid  array parts can expose hundreds of electrical   signals in only a few square millimeters,  so modern boards need ultra-thin traces that   run in three dimensions just to spread those  signals out far enough to wire up the part! But what about those fancy flexible circuit boards  the kids keep talking about? Will we ever be able   to roll up our iPads and smash a mosquito with  Reddit? Flexible circuit boards are actually   really common nowadays. The only difference  between a flex board and a rigid board is that the   flex board replaces that fiberglass with layers  of a thin heatproof rugged plastic called Kapton.   Flex PCB's are way thinner than fiberglass and you  can integrate cables into the board itself. Flex   PCB's are great for bending around obstacles and  for tucking electronics into nooks and crannies.   What they're not very good at... is flexing.  The first problem is that the board can bend   but the components can't. The second problem is  that flexible PCB's take damage every time they   wiggle. Eventually the layers of plastic and metal  will delaminate and the board will peel apart.   The thicker the board is, the  more it strains when it flexes,   so we can't pile up multi-layer flex boards  the same way we can stack up rigid boards.   [Canine ingestion] Modern devices combine a stiff main board  that has the most intricate circuitry   with flex PCB cables and modules wherever  the engineer can tuck them. Flex PCB's are   really designed to flex just a single time,  and that's when the device is assembled. But can't we just go back to sticking components  right to each other, or even integrate every   single component into one giant mega-chip?  That way, we could trim off most of the board   and make the device that much smaller. Well,  not really. The ability to put off-the-shelf   parts on custom boards, even though it makes the  part a bit bulkier, is actually a good thing.   Modern devices have a lot of parts - you got  processors, memory, modems, transceivers, sensors,   secret government espionage chips, security chips  to protect you from secret government espionage   chips, and blinky blinky lights. Getting all those  manufacturers to combine all their parts together   would be an absolute nightmare, and even if you  managed to pull it off, you'd never be able to   make any design changes because everything's fused  together into one chip! Integration is risky - the   more stuff you cram into a single package, the  higher the odds that a single defect breaks the   entire thing. Stuff breaks - if everything is in  one place, the device is impossible to repair. This is still a big deal. Like, some hardware  is always dead on arrival and it's cheaper to   repair it than to replace it. Manufacturers have  also stopped making super-low-end devices because   they can refurbish last year's  model and sell it at a discount.   If everything was integrated into a  single part, that wouldn't be possible.   On top of that, integrating everything makes  you your suppliers' bitch because all it   takes is a single supplier to threaten to revoke  their license and your entire product is trashed.   Some components need to maintain social distance  from other components. Antennae, for instance,   pick up interference unless they've got breathing  room, and in a high-voltage board like this power   supply, arcs will jump between traces and blow  [REDACTED] up unless they're a certain distance apart. Some parts also need special packaging; this is  a pressure sensor that needs a little breathing   hole to allow the air to flow in. This  is a pulse oximeter that's in a special   glass capsule so that it can see the skin  clearly. There's just no getting around it;   you need a bunch of parts to make electronics,  the best way to put a bunch of parts together   is on a board, and the best way to make a board  is to print it. No matter how many parts are in   your design, no matter how exotic they  are and which suppliers are involved,   pretty much anyone can put anything into any  project as long as they can mount it on a PCB.   Any parts can be combined in any configuration,  and you'll always know you'll have this thin,   sturdy board, keeping everything  together, with convenient mounting holes. Integration is kind of happening in a way, but  instead of putting every component into one chip,   manufacturers are integrating many  components into one module. For instance,   the camera module compresses images. The  fingerprint reader handles your security.   The display has the drivers embedded right into  the glass. The wireless modem, processor, RAM,   graphics chips, are all integrated into a single  part. This is really the best of both worlds,   because the manufacturer has already done a bunch  of your engineering, and if something breaks   you just replace the module. This  is great for the user because, like,   anybody with a screwdriver can replace a broken  camera if the new one just pops into place. So what's the future of the PCB? Are we still  going to be using copper and fiberglass when   Brooklyn is under eight feet of water? Yeah,  I think we probably will. The PCB production   process is just so well-established and so cheap  that, like, boards are already as accessible as   they ever need to be. There have been some  nitty-gritty technical advancements; like,   you can have a sheet of aluminum laminated  onto your board to help spread heat;   you can add plugged vias, which  are sort of vertical wires,   to route super duper dense components; oh,  and now you can get FULL COLOR SILKSCREEN! [Wolf whistle] Electronics are becoming cheap enough that  we can actually embed them straight into   some devices - this is a bunch of RFID tags,  which are a tiny foil antenna and a teeny-weeny   microcontroller built directly into a sticker.  These things don't need a circuit board because   the sticker holds the thing together. Your bank  might have also given you a special bank card   that displays a security code, and that is also  an electronic device with no circuit board. The   electronics are embedded directly  into the plastic of the card. There are some interesting rumblings in  the hackersphere, where toxic chemicals   and electroplating tubs are kinda  impractical. 3D-printed circuits are   this idea that just won't die; the idea is, you  print the circuit board out of regular plastic,   and then you print the traces on top of it using  a special conductive material. There's also the   inkjet circuit maker, which uses basically a  modified inkjet printer to draw the circuits   on a sheet of paper using conductive ink made of  silver. Finally, you have the desktop board mill,   which is like a tiny cute little CNC machine  that you put on your desk and it mills you   circuit boards out of copper clad. CNC board mills  have recently become affordable and practical,   and if you're okay with the lack of  solder mask, you can make simple boards   right there on your workbench. Give me  $2500 and I'll do it on video! But what about the super-sci-fi future? Well, there's vitrionics, or embedding electronic   components into panes of glass. This is already  used to make capacitive touchscreens for cell   phones and those super-thin OLED televisions.  If you want to make transparent electronics,   this is how you'll do it... after you invent  a transparent battery, of course. There's   also optronics, which replaces traces carrying  electricity with fiber optics carrying light.   These could run way faster and way cooler  ( temperature and awesomeness) but there   are severe practical problems that have to  be overcome. The main one is that even though   you can easily send data through a fiber optic  line, you can't send much power, so ironically,   you'll have to run wires in addition to your  fiber optic traces to feed power to the chips. [Geordi getting pwned noises]  Data? Yes?  What happened? Any answer would be mere speculation. Decades of experience have proven that  the best shape for a circuit is a board,   and the best kind of board is a printed circuit  board. Printed circuit boards are still the most   common electrical component, even though they're  basically unchanged since we used them to blow   up the Wehrmacht. I think they'll maintain their  position as the literal foundation of electronics   deep into the future. Hopefully you've  learned something about how they work   and why we use them. Thanks so much for watching,  and I hope I've inspired you to bust open your   electronics and dig into the PCB's around you.  Are you interested in exactly how engineers design   these things? Maybe you're really interested in  those part-placing pick-and-place machines we   talked about earlier? Well, I make videos about  all of those, and if you like the sound of them   apples, why don't you... uh... why don't  you give me a little subscription? Thank you   so much for watching! Voidstar Lab is still  a new channel, and every single view and   comment gives me the warm and fuzzies. May your  boards not catch fire unless you want them to.   I'm Zack Freedman, this is Voidstar  Lab, and I'll see you in the future.
Info
Channel: Zack Freedman
Views: 237,921
Rating: 4.935945 out of 5
Keywords: electronics, circuits, soldering, technology, history, manufacturing
Id: 6je0Ea-jGlI
Channel Id: undefined
Length: 17min 14sec (1034 seconds)
Published: Mon Sep 14 2020
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