Viagrid – PCB template for rapid PCB prototyping with factory-made vias [video]
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I'm not sure I want the trade-off of having to try to fit my existing circuit into those pre-populated vias.
Part of the joy of PCB layout is trying to be "optimal". That might be optimal in board size, optimal in the elegance of the trace layouts. I even trying to minimize vias (or not have them altogether). With prefab vias, there will be kludges to work my own vias into those locations. And, honestly, the unused vias will annoy me as well.
I'm a sucker for solder masks, silkscreening… I think I am too in love with what I get back from Hong Kong and Taiwan.
My "quick prototyping" consists of breadboarding and trashy perf-board mockups.
So many times that I’d happily pay $20 to try a board right fricking now (and I doubt they’ll be $20 all-in).
For me, it would replace breadboarding, not replace a final prototype PCB before committing to a first assembly run.
The author of the video has some previous work on solder masks and silk layers. You may want to check the earlier laser manufacturing videos.
His goal of bringing small scale manufacturing down to the workshop / home garage level is really inspiring and is especially relevant in the modern era of tariffs and economic upheaval.
To get good at something people need to get hands on experience and it needs to be affordable and relatively easy to use. The kinds of tools that Stephen is promoting make that possible and that's critical if we want people to get good at building things.
I will say that his presentation style always tilts me a bit. It's his laugh/excitement always seems forced/fake.
I was keeping up with them for a while, putting up with it/skipping bits (why am I a goblin or ghoul? What does that mean?) but had lapsed and forgotten about it until this submission.
However besides the personal dislike, I think its worthwhile to stop giving so much merit based on advertising "open source" or "effort" or "presentation" etc, because frankly many of these YouTube "makers" and the "maker community" are misguiding a lot of people to make bad designs and waste time and resources. People ought to value correctness and quality a bit more, lest our things become even more enshittified than they are now. One would think that hobbies would be a refuge from disposable low quality shit... yet we get RPi Pico et al (which are arguably getting less shitty but still laughable compared to actually good MCU products) and the people who claim to "out do the big corp" by using a Raspberry Pi with an SDR dongle and saying they achieved $50000 of capability with $60 in parts..
Case in point, the Opulo PNP systems are significantly overpriced and have amateurish mechanical as well as circuit design that are worse than cheaper systems like Pandaplacer in terms of reliability and performance.
I agree that Opulo PNPs are overpriced though, but I'm sure people getting these are aware that it's just a bunch of 20x20 aluminium profiles, 3d printer mgn rails, basic DC pump, etc and parts-wise there's nothing to justify the price, but they get them anyway because of entusiastic community engagement and support aspects - most importantly - in English. And it probably works just fine for the small scale projects they are used in.
- Broken ADC design on RP2040 with nonlinearity at certain codes (and they're not fixing it)
- Shipping chips with exact part number of inductor and specific DCDC layout requirement (like come on, the Chinese are advertising zero decoupling capacitor required and you can route the USB right under the chip in funky shapes and everything "just works".. meanwhile RPi is doing this)
- GPIO current leakage (fixed with a stepping but I would hate to be those who bought a reel of the earlier stepping)
"Actually good MCU products" in my opinion are those with at least a reason to exist. For example the ubiquity of STM32, the radios of ESP32, the high compute of i.MX RT1172, the cheapness of PY32 et al, the low power of Ambiq chips, the reliability of Atmel/Microchip, the USB3 on CH569, the potential true MCU-level-SoC-capability on AG32, etc. When compared with these, RP chips are frankly not innovative at all (PIO does not unlock much actual capabilities besides party tricks). Combined with the general culture of people hyping RPi Pico chips, it results in a culture of ignorance and hype.
Erratas alone aren't a big deal, but the fact that they're happening with such basic things and for no innovation is not a good sign. We shouldn't give RPi a pass just because "it's the good old RPi that we know"
I implore you to open up the errata sheet of stm32g4, just the ADC section alone (or frankly any stm32 mcu) (https://blog.mjbots.com/2023/07/24/stm32g4-adc-performance-p...), and that's an MCU series with focus on analog peripherals.
Stm32 chips are plagued with all sorts of issues and hardware bugs that are very easy to run into. In comparison rp2040 has surprisingly few major defects apart from its ADC implementation.
I see no mention of exact part number of inductor requirement in their hardware design guide, are you making shit up now? They are somewhat more particular in oscillator selection, and unfortunately don't include factory trimmed RC oscillator like most MCUs do these days.
> PIO does not unlock much actual capabilities besides party tricks
Ok, so you've no idea what you're talking about.
RP2040 is widely used in many projects because it has insane bandwidth for MCU in its price category. It can do 4 x 32bit reads/writes per cycle (if those ops are spread across 64kb x 4 memory banks), at 200mhz base clock, which gives theoretical maximum of 3.2 gigabytes per second bandwidth. That is pretty crazy.
This enables you to interface with or easily emulate many highspeed interfaces. And do things like 24ch 400mhz logic analyzers and similar. And this is what they are commonly used for (emulating memory cards, etc)
And that's a 60cent MCU. In this price range MCUs don't have 264kb of SRAM and 133/200mhz much less with two cores, that can push anywhere remotely this insane amount of bandwidth.
rp2040 additionally has human friendly and readable documentation, with truckloads of examples, and API that's pleasant to use. (can't exactly be said about stm32 ref manuals and APIs).
While it is not perfect (rp2040 ADC, and lacks encryption), some of those shortcomings have already been addressed in rp2350, with double sram (520KB at this price point!), floating point, even more PIO, more improved DMA channels and so on.
While cheap py32, gd32, apm32, etc are cool, but they just generic arm32 m0/m4. A 10 cent 24mhz m0 puya with 3kbs sram, isn't particularly impressive when put next to 60cent rp2040 with 80x sram, etc
> Combined with the general culture of people hyping RPi Pico chips, it results in a culture of ignorance and hype.
You haven't opend an errata sheet of stm32 chips even once and you talk about ignorance.
rp2040/rp2350 are unironically one of the best MCUs on the market (esp. in their niche), both in documentation/API and price/perf and features/flexibility in doing highspeed interfaces/bandwidth.
Comparing a 60 cent chip to a 10 cent chip is itself crazy work. That's like a whole three stratums apart in terms of capability. Dammingly, you are forgetting about the cost of the external flash that it requires, when program flash is the main cost of MCUs. It shows you don't have much experience with this stuff.
> I see no mention of exact part number of inductor requirement in their hardware design guide, are you making shit up now?
LMFAO go read the literal datasheet page 455 https://datasheets.raspberrypi.com/rp2350/rp2350-datasheet.p...
They literally had to "work with Abracon to create a custom 2.0×1.6mm 3.3μH polarity marked inductor" like wtf
Besides how it looks like you weren't one of the early adopters (since RPi shipped one abracon inductor with every one RP2350 for a bit), you also clearly haven't designed a board with the chip in question.
> theoretical maximum of 3.2 gigabytes per second bandwidth. That is pretty crazy.
This is what I'm talking about, like honestly what capability does that unlock for you beside party tricks? Can you name anything meaningful beside "logic analyzer" and "some memory card?" Even disregarding that, what can you do with such thruput if you are bottled by USB 1 speeds and a core without FPU? It doesn't come close to being able to do interesting things like LVDS ADCs or actual high speed memory interfaces because of the bit width requirement, yet people will go into a frothing frenzy should you dare insinuate that RPi Pico might be kinda useless
> rp2040/rp2350 are unironically one of the best MCUs on the market (esp. in their niche), both in documentation/API and price/perf and features/flexibility in doing highspeed interfaces/bandwidth.
As you might surmise, I disagree. Go make some actual projects instead of "reading the docs" all day (though I must admit I do the same). Also, it sure looks like our definition of high speed differs by a wide margin
If you had any experience "with this stuff", you'd know 16mbit of QSPI flash (compatible with rp2040) costs 7-8 cents in volume. 64mbits 12cents or less. And would calm your tits. It is okay.
> Besides how it looks like you weren't one of the early adopters
If you had any experience "with this stuff" you'd know better than to buy reels of mcus on rev1/rev2 that haven't been on the market for atleast a year or two.
> bottlenecked by a core without FPU
Why would lack of FPU impact bandwidth? Lack of FPU is non-issue with fixed point math in most cases.
> I have read the docs, and like I said the point of STM32 is ubiquity
And yet during chip shortages, rp2040 were one of the few MCUs without stock issues or crazy prices... in fact, I've never seen it out of stock. STM32 on the other hand... ouch. Fun times!
>This is what I'm talking about, like honestly what capability does that unlock for you beside party tricks?
So every capability and use-case that doesn't tickle your zoomer sensibilities is a party trick?
Okay.
It seems to be a kit, not a pre-assembled unit. It's hard to tell from the documentation. It looks a bit flimsy for the rigidity required. Same problem as the Liteplacer. To download the "white paper", you have to go through the onboarding funnel and agree to being spammed, which is always annoying.
The frustrating thing about prototyping pick and place and solder paste machines is that production people want speed, which costs. The prototype-only market isn't big enough. (Has the low-cost reflow oven situation improved? The low-end ones had hot spots that would scorch a board.)
Compare this Neoden line of products.[3] No idea if these are any good. US$3000 for pick and place. That looks like a much more useful product than the Opulo machine. It can work with a wider range of part sizes; not everything has to be on an 8mm tape.
(The problem with plated-through holes, of which "vias" are a subset, is that they require a number of chemical baths which aren't worth setting up for a one-off.)
[1] https://www.opulo.io/products/lumenpnp
[2] https://www.liteplacer.com/
[3] https://www.alibaba.com/product-detail/SMT-PCB-Production-Li...
Once you get to a certain component size and layer count, home making PCBs doesn't make any more sense.
I do still order only PCB and solder stencil initially to hand solder and test boards before PCBA but by that time I have tested most on breadboards and fitted the PCB in CAD to wherever it will go.
While waiting the 1-2 weeks for the boards and components I usually work on the firmware.
The other domestic fab I tried dicked me around for three weeks before I got a quote. $5k this time.
PCBway wants $500
These types of lasers might be a stopgap if tariffs make buying from those companies inordinately expensive, however the extreme cost, and the need to do a bunch of cleanup kind of makes me suspect there needs to be another iteration of this tech.
https://old.reddit.com/r/PrintedCircuitBoard/comments/9bt5ed...
oshpark puts panelization tabs right in the middle of a row of castellated edge contacts.
And they often take longer to ship to me in NJ than Elecrow, a shop that's even cheaper than jlc or pcbway, without even using DHL, just the cheapest shipping.
Never mind the lack of features. I have a board that needs 1.2mm pcb. Well on oshpark I guess I can make 0.8mm work. 3d print a filler plate or something. But what I really need is 1.2, and all the chinese shops have it, not even special extra cost, or maybe barely.
15 years ago oshpark was great.
And $2.10 plus shipping for 5 boards, $7.50 for ten (4layer FR4, HASL, small boards) is crazily subsidized for prototyping. It’s like free prototyping boards. Even 6 layer and flex boards are cheap. They also have crazy cheap CNC and 3DP, but I haven’t tried that yet.
Also the integration of the free design tools (easyEDA pro , DFM review, etc) is unbelievably efficient with one-click to order parts or boards lol
I have had a great customer experience so far, but I do suspect they are either subsidized or use a lot of loss leaders to pull people into the ecosystem.
Other companies may offer better quality, but I’m fine with Toyota, I don’t need Rolls Royce for what I’m doing.
Even without subsidies this company would have structural competitive advantages over US PCB manufacturers. Its silly to think a US PCB manufacturer would be competitive in the same way without having something like the digikey warehouse and associated manufacturing chains right next door.
There are 1000's of corn farmers in the US, because the US has decided it was strategic and sees to it that there is always a lot of corn production capacity, even if it means buying the corn itself or artificially disposing it in some other way like making a law to use ethanol.
The point was that JLC are not strategic because they are unique. The cause & effect goes the other way. JLC are not unique because their industry was strategic.
... wait, does this also explain apparent advantages in software as well as disadvantages in hardware that the US has?
Specifically we had issues with added graphics not in my GERBERS, and some through hole plating issues.
I like that it allows you to prototype using the same smt parts that you will want in the end, without having to try to buy redundant DIP and THT copies of every part, or build a bunch of dip breakout boards for everything.
That's potentially a pretty big deal.
The reasons why I'll probably never use it are:
* It's value requires that it's not merely possible but totally convenient for you to print and etch.
Chemical etching with a sponge seems like it should be no problem but how to print? I don't have a laser engraver and I wouldn't use a router for this even if I had one. I do have an fdm printer. Has anyone one used fdm to print etching mask onto copper? I have a laser printer, is there some kind of special sheet that you run through a laser printer and then transfer like with an iron or something? I see a few almost possibilities but I just don't see it being actually convenient to where I would actually do it more than once just for the experience.
But if somehow you had this down, then great. This is just swapping out a plain blank copper pcb for a more useful one. It's a win.
* I bet I almost never have a design that fits within or around the pre-allocated number of vias and the pre-allocated positions of them.
Most of my things need a at least one 28 to 40 pin header somewhere, or 2. Even if I use surface mount versions that solder just to the top, that's still a lot of signals that usually can't all live just on top, they have to cross each other and that means more than a dozen vias. If I made my own version with more vias, they would probably just be in the way. Here he does try to make clusers of vias so there are both vias and clear spots. Maybe there is a way to just keep working on that idea and develop other layouts with more vias that still leaves clear areas.
* All my stuff, the circuit itself is usually pretty simple and doesn't need much prototyping. The initial lash-up to get the circuit working at all, is usually not where I spend all my time.
I might have a lot of traces but it's all just data & address lines without much mystery about if it will work or how it will work.
I go through a lot of revisions but prototyping wouldn't have changed that, I just like refining the design over time because it's easy to do in the cad software. It's (apparently) a passtime I enjoy. Most of the design is actually in the exact board shape fitting into something else, and fitting everything into a small space while still being hand-solderable with only medium skill/tools, ie tsop & qfn but no bga, all 0805, etc, so it can be built by more people instead of just myself or an actual fab shop.
I think for most of my stuff, this just wouldn't get me a faster development cycle. The initial lash-up to get the circuit working at all is just not where I spend most of my time, and I think that's what this primarily helps with.
Or, it helps make a better final version if you don't really care too much what size & shape the board is, any old square is fine, but for some reason you do care about having 20 vias instead of 20 bits of wire?
But I don't think everyone else is me. I mean this guy sure seems to think it's solving a problem for him.
Also you don't have to reroute, you can build it the same.
And regarding high-speed digital buses... are we being genuine here? Just the fact that you cannot have meaningful design over ground return paths with this thing makes any moderately fast digital link unfeasible. Best you'll be able to manage is regular speed SPI (which also does not need a board like this), you can forget about RGMII, ULPI, LVDS, MIPI, SLVS-EC, or anything else for that matter.
For those who don't know: Vias are not only used to get an electrical connection from one side of the PCB to another.
You also need them to keep radiation in check and often to move heat away.
With this technique, good luck getting through EMC testing for anything but trivial circuits.
Hence my post saying vias are useful at all stages of prototyping.
> good luck getting through EMC testing for anything but trivial circuits
It's for prototyping! Nobody says you can't add more in a board spin.
> you cannot make much more than a basic breakout board
Except, you know, all the supporting circuitry, connectors, maybe microcontroller and JTAG header which could be put on instead of bodged together with random wires -- exactly the problem this is targeted to solve.
> Just the fact that you cannot have meaningful design over ground return paths with this thing makes any moderately fast digital link unfeasible.
You can with a 4-layer version, which is brought up in the video as one of the obvious improvements to make/try, and you would need/want the vias at least to route the other signals around your high-speed traces.
2. In most of US/EU you get them for $5 in up to _two weeks_, or in two days for $5+$2X or more which adds up quicklyand can be more than the rest of the project. Even next day shipping loses out badly to making it yourself in ~30 minutes, turns into two days delay unless you're lucky to have an idea in the morning and time to work on it in the next afternoon, a lot of the time i see people bodging things i'd make another board for because it's just easier.
I think the issue is that if there's a tarnish on the copper, it will work okay. The problem is when you polish the copper. It turns reflective and will not absorb the energy of the laser.
A 5W UV laser or a 100W MOPA laser will give better results. I'm thinking about a 200W version for black friday.
show me how You can to do this.
Yet I do say vee-ya for the holes in pcbs. So I say the same word both ways at different times.
And I guess I say route both ways at different times too now that I mention it.
(Fwiw route can be correctly pronounced differently in different circumstances: BrE is 'follow that [root] to the woodshop and [rowt] a nice profile on this piece'.)
(because you put "acronym" before "/short word")