PCBWay sponsorship: full-size SD module for Arduino projects

A few weeks ago, I had the surprise to get an email from PCBWay about the BurgerDisk project. Basically they offered me to sponsor my PCBs up to $100, in exchange for a review.

So far I always refused that kind of thing as I don’t want getting money to get in the way of my independance, but they seemed OK with me writing exactly what I want so I felt I can accept their offer and still be completely honest about the service they offer.

I actually already used PCBWay. When I first started the BurgerDisk project, the first few revisions of my PCBs were made by them. They are really cheap when you want to prototype simple designs, like about $12 shipped for 5 two-layers, non-assembled PCBs. I then switched over to JLCPCB back in January, I think, when PCBWay stopped offering Paypal as a payment option and didn’t have an easy replacement at the time. They now take credit cards and have various options that come without large fees, making checkout easy again.

I then started using SMD components, and got some PCBs made by JLC, with a few disappointments down the road. If the design is good, there is no issue. JLC’s BOM format is nice in that you can add LCSC references and pinpoint exactly the components you want, and check and correct positions interactively before ordering. If the design is wrong, their (human) DFM analysis might catch it, but they do it fast, and can also miss pretty important details like a non-filled ground plane, effectively making all components ground-less, which… doesn’t work a lot.

PCBWay doesn’t offer that level of automation, and the components’ characteristics have to be described in the BOM. So you add your design to the cart, then wait for them to come back to you. This makes the ordering process slower, but that can be good – I’ve removed things from my cart after noticing errors, or non-optimal things I didn’t see at first.

So, I decided to take their offer and have them make my full-size SD card module that I want to have as an option for the BurgerDisk. There is no ready-to-use full-size SD module on AliExpress, as the ones they sell lack level shifters for the MOSI/MISO/CS/SCLK signals, making them dangerous for SD cards (which take 3.3V) in conjunction with 5V MCU designs like the Arduinos.

I also like, a lot, a few of PCBWay’s choices: upload a Kicad-made design, and they’ll give back 10% of the order to the Kicad project. This is great to see a large company actively contribute to free software development, and this doesn’t happen enough. Just this is, to me, a huge reason to use PCBWay.

They also have a “Share & Sell” program for open-source designs (like mine). Once ordered, you can in one click make your design public on their website, and let people order your design from them in a very simple way. This should let anyone who wants a full-size SD module order some from them, in a very easy way. These will end up more expensive than AliExpress modules, which are probably made by the millions and are sold at about $1 each.

After uploading my Gerber, BOM and Centroid files straight from their Kicad plugin, I filled in details like how many units, which side(s) to assemble, etc, and added the project to the cart.

At this point, the PCBWay people check everything, and choose components for you (it’s also possible to specify them yourself), based on the Value, Footprint, Description, etc BOM fields. For example, it’s possible to specify your resistor as “150 ohms, 100mW, 0603”. That avoids a long search for every part of your design like one has to do at JLC; but it also makes it harder to check what PCBWay has in stock and adapt in advance if necessary. This is not a problem for common components, but it might be for more specific ones. For example, in my SD card module, there is a specific voltage regulator (SE5218ALG), a specific level shifter (TXB0104PWR) and a specific SD holder (SD-106M). They had to order at least one of those, I guess, which made the fabrication time a bit longer: I ordered on March 16th and they shipped on March 31st.

The “less automated” process at PCBWay can seem like an annoyance, but that makes errors less likely to go unnoticed. For example, I once received a batch from JLC where the ground planes were… not there. It was entirely my fault, they weren’t in the Gerber files, but it went to production as is, and as you can guess, that batch ended up in the trash very quickly. This kind of blunder should not happen at PCBWay.

In terms of pricing, they’re quite competitive. A 20 units batch of my SD module is $75, which makes each $3.75, 10 cents more than the same design at JLC.

These 10 extra cents are, in my opinion, very justifiable by the unique features of PCBWay, mainly their engagement with the free software / open source communities. They give at least $15.000 per year to the Kicad project, and sponsor a large number of student and open-source project. That’s in my opinion a very good stance.

All in all, this experience was good. The fact that people actually looked at the design before fabricating was reassuring for me, as I am still kind of a PCB-design baby. Iteration speed on assembled PCBs is a bit on the slow side, but bare PCBs are fabricated much quicker.

As this project is open-source, I have shared it on PCBWay’s sharing platform, so if it interests people, they can have it fabricated easily: An SD-card reader module for 5V MCUs.