Ask HN: Do you make your own PCBs? If so, how?
Curious to see if anyone has a good CNC milling machine that's "cheap" and works very well with PCB boards.
Do you have another method that is fast, easy, and clean?
Do you have another method that is fast, easy, and clean?
If you're set on doing them in house and aren't budget constrained, I usually recommend an Othermill (Bantam) or a Nomad 883 or a Roland (all of which will easily get you above $2K). If you're cost constrained, I'd stick to etching boards using the toner transfer method.
But fast, easy, clean (and cheap)? Order them from a PCB house. If that's not of interest, I suggest you get very specific with your budget.
I've used an Othermill. Absolutely fantastic piece of kit, it's saved me a lot of grief. But making SMD work is out of the question. (Yes, you can get a 1206 to work with the Othermill. No, you aren't going to get a QFN16 with an exposed pad to work. Or for that matter, a QFP16. Or even an SOIC16.)
I don't know who owns that site, but I think they have found a great little niche for advertising.
* Print copper mask onto transparency film using a laser printer
* Very carefully iron the transparency film, print side down, on a standard copper FR4 board
* Even more carefully, peel the transparency film back, and the mask should stick to the copper board (you might have to try a few different brands of transparency film for this to work)
* Mix 50/50 hydrogen peroxide and vinegar in a tub, put the PCB in but elevate it off the bottom of the tub
* Add salt until the copper starts coming off the unmasked parts of the PCB, and agitate the entire thing somehow (I use a busted cell phone with an app that makes the vibrator run continuously)
After a while, maybe an hour, you'll be left with an etched board, then rinse and scrub the mask off.
It takes some practice to get the quality level to the point where you can reliably make thinner traces on the board, but it's entirely doable for small quantities. I recommend doing 2x2 or 3x3 boards at a time so a few rejects are ok.
It's not the fastest or easiest method, but if you're really screwed and you need a board right away, it's possible to do this process with nothing but a Walmart.
In case I need to do SMT parts, I don't bother trying to make SMT traces using this method; I keep some SMT to DIP adapter boards around so I can just solder the DIP through holes onto one of these ghetto PCBs.
Although H2O2 and vinegar are both common household chemicals, the resulting bath is mildly corrosive to metals and apparently dental enamel, so treat it with some respect and neutralize it with baking soda before putting it down the drain. Don't throw it in your yard, it seems to sterilize any soil it comes into contact with.
I'm not entirely clear on the chemistry of what's going on here, but I'm pretty sure the oxidized copper residue left in the bath is low level toxic waste, so filter that out before getting rid of the bath chemicals. I let it dry out and I dispose of it at the battery disposal center in my building.
I few months ago I would have dismissed DIY PCBs altogether in a heartbeat. But I visited my friend who etches PCBs on the regular and as long as you are OK with the limitations there is a lot to be said for holding your design in your hand minutes after having layed it out. I wrote a bit about this experience in my blog: https://blog.monostable.co.uk/posts/etching-oscillators-in-z...
precision and accuracy is all about alignment, so i built alignment guides into all my printouts.
I uploaded some photos of a one + the alignment guides I used, i even did nickel plating and a silkscreen on this one...
heres a short video of the CNC drilling machine too, it was homemade
https://www.youtube.com/watch?v=NiIWB1PsAg8
used to take maybe 1-2 hours start to finish to manufacture a full PCB
Great job!
If I want full-up assembled prototypes I use macrofab.com. I can usually get fully assembled prototypes to my door in ~3 weeks for $30-$100/unit. Manufacturing and assembly is so cheap now I don't even bother doing any of it at home anymore and only keep a small stash of parts for troubleshooting/debug in the home lab.
If you're in Shenzhen, don't bother making your own... you can even get prototype flex PCBs in a couple of hours.
The chemicals, heater, tank, maintenance and disposal are a PITA.
It's fine once or twice, but generally it's not scalable.