4 ms·

Ask HN: Do you make your own PCBs? If so, how?

18 points by mrburton 8y ago

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?

mrburton 8y ago
I'm open to all options - but it could be done using a nice milling machine thats under $200 and comes recommended, please share the model?
m1573rp34130dy 8y ago
have you tried photographic methods... such as mask and photo +ive/-ive etchant resist? you can mill the photomask for serial production...
- mrburton 8y ago
  I haven't yet - I read about it. It would be great to have a small milling machine that sits on the desk and can do PCB for say $200. I would cry :)
  - m1573rp34130dy 8y ago
    if you want to use SurfaceMountComponents you may have trouble with the milling machine approach due to constrained spaces...if you only need discrete analogue or large scale digital boards milling maching is not a problem, a really sweet CNC setup will have a learning mode so you can mill a one off by hand then let the machine copypasta the rest of the boards in large number...look for stepper motor controll projects and raid some dead printers and CDdrives for tasty parts and you are well on the way to a kewlissimo homebrew...
ChrisGammell 8y ago
This is a much discussed subject in the electronics community. I just love soldermask too much. Not only is there potential for colors and art and a bunch of other aesthetic reasons, but the improvement of my soldering makes it all worth it. Cheap PCB fabs from China do default 24 hour turns + 3 days of delivery from DHL...so yeah, I just do that. 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.
- bjt2n3904 8y ago
  Soldermask, and through hole vias for that matter. 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.)
- jdc 8y ago
  Any recommendations on PCB fabs?
  - dahtguy 8y ago
    PCBway has been outstanding for my personal projects. Ludicrously cheap to the point where I have no problem buying 4 or 5 extra copies just in case!
  - ChrisGammell 8y ago
    Usually I am loathe to mention them by name because it brings the spammers in like crazy but I use and have liked AllPCB. I found them on PCBshopper.com, which is a good way to comparison shop for the type and size of boards you'll need: https://pcbshopper.com/ https://pcbshopper.com/ I don't know who owns that site, but I think they have found a great little niche for advertising.
rasz 8y ago
fast, easy, and clean? add cheap and you get JLCPCB
- leetbulb 8y ago
  I've heard good things. They even sponsor GreatScott! :D
modells 8y ago
Embedded systems engineer of the sharpie resist era. 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.
dublin 8y ago
Unless you're building a stupid-simple board w/old-style through-hole components, give up on milling and just use an internet board house. (FWIW, Sunstone/PCBExpress has done great boards for me.) Why? 1) Layers & plated vias: You want them, even if just for power and ground planes; 2) Solder Mask (really makes manual soldering easier, esp for fine pitch chips), and opaque solder mask can provide a little early IP obfuscation; 3) Silkscreen annotations, but most importantly, especially if doing Surface Mount components, 4) Solder paste stencils - if you're doing fine pitch surface mount you do want this! (Make sure your solder mask prevents bridging between adjacent pads!)
- dublin 8y ago
  And FWIW, I haven't used anything but Internet PCB shops for prototypes since 2001 - that's the point at which I needed surface mount, so I made the change, and never looked back. If you're really in a hurry, you can pay a bit more to expedite and get everything in a day or two (usually the stencil's the long pole in the tent...) We did two board spins a week for rapid development projects, without no problems - in 2002!
robjampar 8y ago
I always found the best combination was a photo resist method, with a small CNC machine for drilling and routing the PCB. 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... https://imgur.com/a/GNZKaMK https://imgur.com/a/GNZKaMK heres a short video of the CNC drilling machine too, it was homemade https://www.youtube.com/watch?v=NiIWB1PsAg8 https://www.youtube.com/watch?v=NiIWB1PsAg8 used to take maybe 1-2 hours start to finish to manufacture a full PCB
- mrburton 8y ago
  That image is so nice! Do you have a video of you doing it from start to end? I would love to see that. Great job!
kasbah 8y ago
Etching doesn't have to be super messy if you are experienced in it and have all the equipment set up. I would also recommended using ammonium persulphate over ferric chloride as it's a see-through and a bit less nasty. 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-zurich https://blog.monostable.co.uk/posts/etching-oscillators-in-z...
- conesus 8y ago
  I recently learned that on a single sided pcb you can use a zero ohm resistor to effectively cross over a trace, netting you half the benefit of a 2nd layer without having one.
trelliscoded 8y ago
I normally outsource my PCBs to a board shop, but every once in a while I have to make a one-off. I'm not sure where I read about it originally, but I use a process that doesn't require any special, well anything: * 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.
jotux 8y ago
If I want a quick-and-dirty prototype or breakout board and I don't mind waiting 2-3 weeks, I use dirtypcbs.com. Always good quality and crazy cheap. 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.
vinylkey 8y ago
OSH Park (https://oshpark.com/ https://oshpark.com/) seems to be popular in the guitar effect building community.

18 points by mrburton 8y ago

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?

mrburton 8y ago

I'm open to all options - but it could be done using a nice milling machine thats under $200 and comes recommended, please share the model?

m1573rp34130dy 8y ago

have you tried photographic methods... such as mask and photo +ive/-ive etchant resist? you can mill the photomask for serial production...

mrburton 8y ago
I haven't yet - I read about it. It would be great to have a small milling machine that sits on the desk and can do PCB for say $200. I would cry :)
- m1573rp34130dy 8y ago
  if you want to use SurfaceMountComponents you may have trouble with the milling machine approach due to constrained spaces...if you only need discrete analogue or large scale digital boards milling maching is not a problem, a really sweet CNC setup will have a learning mode so you can mill a one off by hand then let the machine copypasta the rest of the boards in large number...look for stepper motor controll projects and raid some dead printers and CDdrives for tasty parts and you are well on the way to a kewlissimo homebrew...

ChrisGammell 8y ago

This is a much discussed subject in the electronics community. I just love soldermask too much. Not only is there potential for colors and art and a bunch of other aesthetic reasons, but the improvement of my soldering makes it all worth it. Cheap PCB fabs from China do default 24 hour turns + 3 days of delivery from DHL...so yeah, I just do that. 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.

bjt2n3904 8y ago
Soldermask, and through hole vias for that matter. 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.)
jdc 8y ago
Any recommendations on PCB fabs?
- dahtguy 8y ago
  PCBway has been outstanding for my personal projects. Ludicrously cheap to the point where I have no problem buying 4 or 5 extra copies just in case!
- ChrisGammell 8y ago
  Usually I am loathe to mention them by name because it brings the spammers in like crazy but I use and have liked AllPCB. I found them on PCBshopper.com, which is a good way to comparison shop for the type and size of boards you'll need: https://pcbshopper.com/ https://pcbshopper.com/ I don't know who owns that site, but I think they have found a great little niche for advertising.

rasz 8y ago

fast, easy, and clean? add cheap and you get JLCPCB

leetbulb 8y ago
I've heard good things. They even sponsor GreatScott! :D

modells 8y ago

Embedded systems engineer of the sharpie resist era. 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.

dublin 8y ago

Unless you're building a stupid-simple board w/old-style through-hole components, give up on milling and just use an internet board house. (FWIW, Sunstone/PCBExpress has done great boards for me.) Why? 1) Layers & plated vias: You want them, even if just for power and ground planes; 2) Solder Mask (really makes manual soldering easier, esp for fine pitch chips), and opaque solder mask can provide a little early IP obfuscation; 3) Silkscreen annotations, but most importantly, especially if doing Surface Mount components, 4) Solder paste stencils - if you're doing fine pitch surface mount you do want this! (Make sure your solder mask prevents bridging between adjacent pads!)

dublin 8y ago
And FWIW, I haven't used anything but Internet PCB shops for prototypes since 2001 - that's the point at which I needed surface mount, so I made the change, and never looked back. If you're really in a hurry, you can pay a bit more to expedite and get everything in a day or two (usually the stencil's the long pole in the tent...) We did two board spins a week for rapid development projects, without no problems - in 2002!

robjampar 8y ago

I always found the best combination was a photo resist method, with a small CNC machine for drilling and routing the PCB. 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... https://imgur.com/a/GNZKaMK https://imgur.com/a/GNZKaMK heres a short video of the CNC drilling machine too, it was homemade https://www.youtube.com/watch?v=NiIWB1PsAg8 https://www.youtube.com/watch?v=NiIWB1PsAg8 used to take maybe 1-2 hours start to finish to manufacture a full PCB

mrburton 8y ago
That image is so nice! Do you have a video of you doing it from start to end? I would love to see that. Great job!

kasbah 8y ago

Etching doesn't have to be super messy if you are experienced in it and have all the equipment set up. I would also recommended using ammonium persulphate over ferric chloride as it's a see-through and a bit less nasty. 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-zurich https://blog.monostable.co.uk/posts/etching-oscillators-in-z...

conesus 8y ago
I recently learned that on a single sided pcb you can use a zero ohm resistor to effectively cross over a trace, netting you half the benefit of a 2nd layer without having one.

trelliscoded 8y ago

I normally outsource my PCBs to a board shop, but every once in a while I have to make a one-off. I'm not sure where I read about it originally, but I use a process that doesn't require any special, well anything: * 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.

jotux 8y ago

If I want a quick-and-dirty prototype or breakout board and I don't mind waiting 2-3 weeks, I use dirtypcbs.com. Always good quality and crazy cheap. 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.

vinylkey 8y ago

OSH Park (https://oshpark.com/ https://oshpark.com/) seems to be popular in the guitar effect building community.