An introduction to getting printed circuit boards (or PCB-type front panels) fabricated.
First someone needs to design the PCB. Let’s assume that’s done already. Then they have to produce the files known as Gerbers that describe the PCB for the fabricator (and the drill files, usually included with the Gerbers though technically they’re not Gerbers). Let’s assume that’s done already too. You’ve found a repository that has Gerbers for a PCB you want; what do you do?
Submitting Gerbers
In short, you need to compress the Gerber and drill files to .zip format, go to wherever you’re having the fabrication done (see below), upload the .zip file, choose a color and specify a quantity, and open your wallet.
In less short: For each PCB there needs to be a zipped Gerber folder. Some projects have more than one PCB and there needs to be a separate Gerber folder for each. Typically a Gerber folder for a single PCB will contain something like:
drill_report.rpt
herovco_back-CmtUser.gbr
herovco_back-CuBottom.gbl
herovco_back-CuTop.gtl
herovco_back-drl_map.pdf
herovco_back-EdgeCuts.gm1
herovco_back-MaskBottom.gbs
herovco_back-MaskTop.gts
herovco_back-PasteBottom.gbp
herovco_back-PasteTop.gtp
herovco_back-SilkBottom.gbo
herovco_back-SilkTop.gto
herovco_back.drl
herovco_back.gbrjob
(Not all of which actually are needed by the fabricator but it does no harm to include them all. Note that different fabricators have different requirements; Gerbers generated for upload to JLCPCB may not be what OSH Park needs, for example, so it’s best to be sure the Gerbers you’re using match up with your fabricator.)
All these must be put in a folder and compressed to a single zip file, and then likewise but separately for each PCB (or front panel) you want to order.
Beyond color and quantity, there are other options they give you but most you can ignore — the default is what you want. Most places have a minimum order of 5 copies of each board, and if you want more it has to be a multiple of 5.
Front panels
For front panels (faceplates) there are a couple of extra bits.
Aluminum?
Some vendors offer the option to use aluminum as a substrate instead of FR4, which can be an attractive option for front panels. There are some things to consider doing if you’re going to go with aluminum. Skip this section if you want FR4 panels.
Note that double sided aluminum is either (depending on the vendor) unavailable or staggeringly expensive. Fortunately single sided is fine, for most panels.
Not sure about other vendors, but for JLCPCB I have read that if you submit an order for an aluminum panel they will simply disregard the Gerber files for back copper and back mask, and will make all holes non plated through. So you can use the same Gerber/drill files as for two sided FR4 panels. But in the interest of clarity my practice is to delete (or just not generate) the back copper and mask files, and to submit only an NPTH drill file. If in the design all the holes are PTH, you can delete the NPTH file, rename the PTH file to NPTH, and use a text editor to change “PTH” to “NPTH” in the file contents. If in the design there are both PTH and NPTH, I find it easiest to tell KiCad to put both in a single drill file, then edit the file name and contents to make it clear it’s for NPTH holes.
You can and probably should (see below re: order number) include a back silkscreen layer for aluminum panels.
Front panel Gerber submission
If there’s an option to skip electrical testing, choose it. (At JLCPCB uncheck “flying probe test”.) Also add a note like:
This is a faceplate. There is no circuit, only copper fills. Ignore any electrical errors.
Fabricators usually want to silkscreen an order number on the product, and you probably don’t want that on the front of your panel. Request that they omit the order number or put it on the back of the panel. At JLCPCB you can check “Remove Order Number: Specify a location” but for this to work, the PCB design must include “JLCJLCJLCJLC” somewhere on the panel silkscreen to mark where the order number should go. You can tell them not to place the order number at all, but that costs extra.
Pro tip for JLCPCB
When you add a new board to an order it remembers the options you selected for the previous board. So if for example you want to order several PCBs and several front panels, do the PCBs all together, then do all the panels. Then for instance you only have to type in the “this is a front panel” note once (and you’re less likely to forget to check off “specify a location” on one of them).
Which fabricator?
As for which fabricator to use, it depends on what you’re looking for. Generally JLCPCB has the lowest prices, by a lot in many cases. Then again, several places offer a discounted price — around $5 for five boards — for anything less than 10 cm on a side (and no special options) that renders price considerations minor. PCBWay offers more options including more colors. OSH Park has a good reputation if you want to use a US based company, but at a significantly higher cost per unit area than most of the Asian companies, and with few color options. However, they have free shipping to US addresses and their per unit area price doesn’t bottom out at some minimum, so for very small boards, under a square inch maybe (good for e.g. SMD breakouts), they can be significantly cheaper than anyone else. If you want to check prices at a variety of companies you can use https://pcbshopper.com/ . Fill in the form with your PCB’s dimensions, how many you want, what color, and so on, and it does the comparison shopping for you. It misses some options, though, like OSH Park’s “Super Swift” service where you pay more for faster turnaround. There also are reviews of various companies, and some get very low ratings, so it’s worth looking at this site before choosing a fabricator.
