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by dhosek 20 days ago
OK, so people are ordering a custom PCB from China for a one-off? Whatever happened to making them at home? I remember my brothers doing this in the bathroom sink with a board coated with copper¹, some special markers to draw the circuit on the board and chemicals to wash off the extra copper. I’m guessing they might have used our dad’s electric drill to put some holes in the board as well, but looking at the article, this doesn’t seem like an order from China need.

1. Some details may be incorrect as I was 10, this was the late 70s and I only saw the results, not the process.

9 comments

In addition to what others said, home-etched PCBs are just much lower quality. We're no longer living in a world where every component has leads on a 2.54 mm grid, so tolerances matter a lot more. Also, SMD means you really need vias and a solder mask.

The problem isn't that people outsource it, it's that they need to outsource to China. That's an abject failure of domestic PCB manufacturers who simply don't want to deal with retail customers.

Exactly. Even for this small board, the IC has 0.65mm spacing of the LGA pads. It would be pretty difficult to assemble it without solder mask.

Almost everyone who has the experience of etching a board, or even using a router to automate making one, and also has the experience of ordering a PCB, never makes one by hand again.

They are lower quality, but you actually made them yourself, and that comes with a satisfaction that cannot be gained from sending a drawing to China.

Edit: and many perfectly useful projects use through hole components. Not everything of value had a microprocessor

What happened is that you can get a set of 5 custom PCBs for about $2. The quality is much higher and you don't have to deal with nasty chemicals. I'll never manually etch a board ever again if I can help it.
Ferric chloride isn't that nasty, it just stains everything.

Electricity costs 25 pence per kWh here. I don't have to make many boards before JLC becomes cheaper than firing up the heated bubble etch tank.

I first started using JLC instead of etching at home in early 2020, and since then I've had a small child, so yeah I'm not running the bubble tank with a 6-year-old running around. Maybe in a couple of years we'll do one by hand, drawing the tracks on the PCB with a Dalo pen and so on, because I remember doing that with my dad when I wasn't much older than my son is now.

But that is definitely going to be an Outside Toy.

> Whatever happened to making them at home?

That method works for creating single sided PCBs with through-hole components or rough SMD parts. Double sided PCBs are more effort but still possible.

But everything more complex than that - multiple layers, blind or buried vias, fine-pitch SMD, anything involving clock frequencies higher than say 50-100 MHz or depending on specific impedances or capacitances, or requiring stuff like vias to groundplanes to dissipate heat in copper? No way even for a dedicated hobbyist. And you need special equipment to make a proper stencil if you can't use a soldering iron due to feature size or because it's impossible otherwise (=BGA parts).

And where it gets really spicy is sandgrain sized SMD parts (0201 and smaller). Even for professional repair shops, that size requires experienced experts...

These days, a one-off PCB is dirt cheap. They’ll provide and solder the components for you, for less money than you could buy them to do it yourself.
I have a small CNC mill and can carve out a board if I don't have time to wait for ordered boards. It's a pain to set up to get it to cut properly, the boards are either one sided or with no vias, and the lack of solder mask makes it harder to solder, especially for SMD components that rely on the solder blob being a certain shape. Additionally, I find that the traces tend to peel off a little too easily, though that may be down to the Ea-Nasir quality copper clad boards I'm using.

It is pretty fast though, and worth learning if you need to do prototyping quickly. You can have a finished board in just hours instead of a week.

I still do mine at home, though I mostly only build one-offs with older style thru-hole components where tolerances are not as sensitive.

Usually I can get away with using a simple Sharpie marker mask, though I've also had good luck in the past with the toner transfer method for more intricate designs:

https://www.thompdale.com/pcb_etch/gotee_board_production/Ea...

I knew someone who destroyed three surface pro keyboards with chemical etcher.

I've got a cat and live in a carpeted apartment. I prefer to keep most projects "dry" for that reason.

LOL tell them you're not supposed to dip keyboards into it!
Buying custom PCBs from China makes sense if you're interested in making electronics. It was more than a decade ago that the equation shifted to the point that making them at home has only made sense if you're interested in the process of making PCBs themselves.

Things like soldermask, multiple layer stackups and plated holes and vias are standard on dirt-cheap Chinese boards but are challenging and time-consuming to do at home.

I used to do this at home. Either thermal transfer or also used a flat bed plotter with an adapter for a Staedler permanent market to draw directly on the PCB. Fun times. Ferric Choride IIRC for etching or you could also use hydrogen peroxide which was much slower...

And yes drill through holes.

Ofcourse only good for two sided (layers) boards at the most.