Usually it costs a lot per unit when you’re only going to make 10 or 20 boards, but if any of you browse Alibaba you probably know there are a ton of desktop pick and place machines, which is likely what the smaller business are using.
What is your experience with this kind of service?
They would hand place and then reflow solder in a small oven , for small runs of up to perhaps 50 boards , and for more complex boards or larger runs, they just sub contracted the work out to larger manufacturers with industrial scale pick and place machines.
i think there is productivity gain if the number of pieces is moderately large but that it seemed hand soldering defeats it next
(edit: mistake, there is a reflow soldering machine just beside. it seemed the pieces hand soldered are simply because it can’t be reflow soldered)
if the pieces are few, pick and place may take a lot of effort to setup and configure/calibrate and possibly may not be worth the setup effort
for a hobby diy pcb in low volumes, these days there are low cost grbl based engraving/milling machines
https://www.aliexpress.com/wholesale?ca … nc+machine
i think that’s pretty effective to make pcbs in small volumes and without chemicals
(oops off topic, but pcba would still matter if one is making the end product in larger volumes)
I have tried using those sort of milling machines to make a PCB, but unless you make PCB’s all the time with them, its a pain to get it working.
The people who have succeeded milling PCB’s often modify the CNC machines quite a lot and also do fancy tricks like terrain mapping of the PCB surface and post processing the plot files to map in the terrain.
The CNC’s kinda work if you want to do pretty basic boards, not with IC’s like the STM32’s pad spacing.
I think for less than 10 boards, just pay extra and get them FedEx’ed back from China etc, then hand place and reflow them.
For anything else, its getting into the small scale commercial sector and you just have to pay $$ and get them manufactured professionally in China or elsewhere
i do agree that for serious production cnc is probably not the way to go, it is probably useful for a prototype or only a few boards and for simple boards,
For production quantities the normal pcb processes may likely be far simpler, faster and is less prone to problems
i think part of the problem is the s/w and the machines themselves, the cheapest (chinese) ones are barebones which leaves everything from zeroing the steppers, calibrating, assembling etc all to the user.
components etc may well be compromised for costs rather than proper design and reliability
in terms of s/w i stumbled into flatcam, it seemed to be quite popular from articles i came across on the web
http://flatcam.org/
I think if you can make these things mill PCBs .
I see that FlatCam shows images of normal through hole PCBs , and I think that sort of PCB is possible, I just found great difficulty trying to mill PCBs for SMD chips.
The machine has been gathering dust for about a year, but it’s on my list as one of the things I have to get working again over the holidays as I want to mill some brackets out if aluminium sheet
https://forum.electricunicycle.org/topi … nc-router/
the author did mention something about smd pcbs, as i’ve not tried these myself i could only post the link to it.
as open sourced softwares take time to develop / improve as well, my guess is that you may like to check the recent version of the softwares (e.g. flatcam) and try them out if you already have a ‘gbrl’ cnc, the author mentioned about the engraving bit : 30 degrees, 0.1mm and a particular type they are moderate cost on aliexpress (e.g. https://www.aliexpress.com/wholesale?ca … +30+degree) in the thread as well, that may make a difference in the engraving/milling process, accurate autoleveling may matter as well as the board may not be level / flat while working on it
there are also things like feed rate i.e. the movement speed which i think would need to be pretty low (slow) on those cheap millers
nevertheless i still think s/w like flatcam is basically evolving and may not (yet) be able to tackle smd mcus
i just thought that if they are sufficiently good they may help if you simply need a single piece of pcb made and that you happen to have the machine handy
for production quantities, for that matter even 10 boards it may be a different story altogether. manufacturing requires reliable processes to achieve decent consistent quality etc in which such ‘prototype’ techniques may fail or is too laborious, slow. i’d think for that it would be better to let those who have the means make them
[aroldorosenberg – Sun Dec 23, 2018 4:27 pm] – LCPCB is going to offer SMT assembly as well.
Oooo la la, music to my hears. My experience with them so far has been top notch.
I find that for < 10 boards its usually more economical for me to place by hand and then reflow. I get my PCB’s from SeeedStudio, mostly 2-layer and under 100x100mm, but I have done larger 4-layer boards from them too (though they get MUCH more expensive). I reflow single sided boards on a hot plate and double sided go on the hot plate then hot air gun for the back side. Usually just prototyping stuff, I probably wouldn’t send out parts to a customer that had been hand built like that. I wouldn’t want to bet money on long term reliability.
If your getting into 20+ boards the cost savings on the components via PCBCart starts to offset the setup time. If you are happy to take ‘locally sourced’ parts for things like pin headers and terminal blocks you can save quite a bit vs Digikey/E14 pricing.
