Why we don't try to make bare PCBs at home
Just don’t.
Bare PCBs are so cheap these days, with such quick turnaround times, that any system (3d printer, circuit mill) is not cost effective in comparison. I was once a member of a lab where we bought an LPKF Protomat S104, with all the accessories under the sun (camera system, oven, vacuum table, lab station for the chemical processes, UV lamps). The entire system cost the lab about $40K USD. We didn’t purchase the press for multi-layered boards. Now, I have nothing against LPKF, and the machine did what it was designed to do. But is it worth it?
It took me a couple weeks to get intimate with the machine. There is software that helps you set up the machine, define the tool magazine, processes gerbers etc. There were quite a few steps required such as milling both sides, masking, drilling the through holes, using a metallic conductive paste to create the vias, placing it on the vacuum to suck the paste through the holes, curing it in an oven, printing the negatives on a laser printer, applying the solder mask, curing the solder mask in an oven, aligning the negative with the board, curing it under the UV light, then giving the board a chemical bath to remove the negative solder mask, laser cutting a stencil for the silk screen, aligning it with the board, applying the silkscreen, then curing the board in the oven again.
After 6 hours of intense board building labor, on a $40K machine using 25$-40$ USD of supplies (some of which were proprietary), I was able to produce a single decent 2 layer board.
I can get 2 layer boards with 3 day turn for 30$ plus shipping online. 4 layer boards for a little bit more.
Perhaps if you are in the middle of nowhere (antarctica), or in a place with no internet connection, or available postal services, or working on something SO top secret that it can’t be sent out, then perhaps this machine makes sense.
Perhaps you don't need all of those fancy frills...just forget the solder mask and rivet the vias.
Sure. Have fun.
If not, just put the money aside for your bare PCB outsource fund.
About the Author
Brien G. East Jr. is the Director of Hardware Design at Blue Clover Devices. A Canadian expat, Brien is happy to embrace sunny California as his new home.
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