The last time I designed and got a PCB ordered was in 2010 and it cost $125 for 5 pieces. As expected, there were a few mistakes in the PCB design and a second batch never got designed.
This time around I found that there were other sources more suitable for hobbyists. The widely mentioned ones were Seeed and Itead. They offered what appeared to be a 50x50mm PCB for $10 which seemed reasonable. But, no, it turned out it was $10 for 10 PCBs! That is like a buck a PCB. This changed the entire way I looked at PCBs.
Apart from a long turnaround time, there was no reason not to dash off a PCB design and then build it, rather than prototyping it on perfboard and carefully checking every part of the design. Sloppiness and laziness are very important to me. To try it out, I took the PCB design that was closest to completion as a test subject.
I had a PCB design for a DCC Accessory Decoder in the final stages of completion. The size was 66x43mm which was awkward. The standard size for PCBs is 50x50mm or the next one up 50x100mm. Not that they have to be this size, just that a 66x43mm PCB would use the 50x100mm cost. It did not take me long to rearrange the components in a 50x50mm PCB. It is a through hole component PCB, the components are relatively large and spread out. Auto-routing is lightning quick.
Then I looked at the product description. There was a star shaped PCB used in the explanation! You mean they can be any shape? It was a bit late to go for a radical shape now. Rounded corners seemed an obvious choice but everyone is doing that nowadays. I settled for a recessed edge on two sides.
Choices like different coloured resists and gold plating are available but at these low low costs, the prices increase manyfold when you opt for them. Still, I could not order the boring old green resist PCBs. I opted for white resist which, I think, comes with black legend. This increased the cost but what the heck, it is still only 15 bucks. It will get relatively expensive when I design an SMD board and opt for gold-plating. A HASL finish may make it a little awkward for SMD soldering.
I went with Itead for no particular reason. Including shipping to Oz and two random open PCBs, the total was AU$18.90. I also opted for 100% etest but this did not seem to affect the cost. I paid for it using Paypal. I got an instant acknowledgement from Paypal and Itead once the order was placed. Now to send the gerber files with the order number as a reference.
The PCB was designed using KiCAD. I generated Gerbers using the Plot menu item. A few files had to be renamed as per Itead’s requirements and the whole lot was zipped up and emailed. A few things to watch out for with KiCAD.
- A separate PCB edges file is not used by Itead. See that the checkbox in the Plot dialog in KiCAD for ‘Exclude PCB edge layer from other layers’ is unchecked so that the PCB edges are included in every layer.
- Create a drill file and include it as well. See that the ‘Mirror Y axis’ option is unchecked.
- Rename all files to follow the naming convention of having the same name but different, capitalised extensions. Change the drill file extension from .drl to .txt
The back silkscreen layer is blank but include it anyway. Note to self – next time get creative with the unused back silkscreen layer. It is unlikely that that back surface is in view but if you must moon someone, at least have an interesting tattoo on your ass!
Once you place the order, you get an email with the order number. In an hour, I sent over the zip file with the order number and in less than an hour, I got a response from Itead that the files have been received. The email went on to say that silence indicates that all is well and the PCB is being made. If there are problems, I will be contacted. Once the board is shipped, I will be informed. The design must have gone swimmingly for I did not hear a peep from them for the next two weeks. In fact, it was nary a peep right up till the time the PCBs actually arrived on my doorstep exactly two weeks later.
Also in the pack were two spare random PCBs. This is a 10 cent option to place your PCB in the pool and get two random Open PCBs. The two PCBs are shown below. Pretty small and when I get around to it, I will try to see what they do. There are no indications in there on any source of information.
To be fair, there is very little on my own PCB to tell someone what to use it for. The Open PCB option was a last minute thing and I didn’t bother putting any info on the PCB itself. It is likely not to be of much interest and the odds of that person having a model railroad is small. It is unlikely that anyone would actually build one. Heck, it would be lucky if I built one and actually got it working! Still, the back of the PCB says Deccan AccDec 2.1 so I better mention it here, so there! It is basically a DCC accessory decoder. When I get it all working, I will document it better. Also, next time around, I may put a website reference on the back of the PCB as well to satisfy the curious.
If you note the back of the PCB, the text appears as tinned text. I thought this would look better than black legend. I did it by adding the text and the logo to both the back copper layer and the back solder mask.
The front has the usual legend and also a serial number that they add. Many on the web have complained about this. I guess it is galling to have your work of art defaced like that. How would you like it if you ordered a painting and they put a serial number across it? But I shouldn’t get too precious about it – it is just a slap-dash run-of-the-mill PCB. It is also under an IC and would not be visible in an assembled board.
Can't wait to assemble the PCB and see if it works. I also spotted Seeed Studio's laser cut acrylic offer. There may be another blog in there...
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