Every PCB Has Its Place

Everyone has their favorite process for PCB fabrication, as long as you’re a happy hacker I don’t think it really matters. But in this post I thought it might be interesting to describe my personal process, and some of the options available.

Making your own at home

The Dirty Electronics Skull Etching Synth a great looking maskless board.

Etching is the classic PCB fabrication option for the home hacker. It’s been many, many years since I etched a PCBs but it can produce interesting results. Some people don’t like it, and I’d personally tend to avoid it as a messy and finicky process. But, if you only need 1 or 2 layer boards with large features (through-hole components are best of course) it can be a viable option. In some cases, I think etched boards look awesome and are a great fit. One example is the skull etching shown to the right. The oxidation and discoloration of the boards adds to the design aesthetic in this case.

Sample1
A simple design milled on an Accurate CNC

For those with a bigger budget a professional milling machine might be a viable choice. I’ve used an Accurate CNC in the past (LPKF and others make mills too), but this is an expensive option (no online pricing, but if $10,000 USD is a lot for you don’t bother). The accurate mill is pretty awesome, it can be fitted with a vacuum bed, automatic tool changer and vision system for alignment. The mill can produce high quality two layer boards with all the holes and vias drilled out. The final step of filling the vias is however manual, but compared to etched boards the results are pretty professional (the mill itself uses milled PCBs!). They claim a 0.1mm (4 mil) track size, I’ve never tried tracks this small but surface mount components were not a problem.

While a fun toy, it’s worth considering if you really need a PCB mill. The only case where they’re really valuable is if you want to be able to iterate over a design with less than a days turn around. This can be useful in RF or low noise designs where you might want to experiment with different layouts, but for other projects the price of a good mill can pay for quick turn around (1 or 2 days from order submission to delivery) on a lot of boards.

Commercial Fabrication

Years ago commercial fabrication used to be a very expensive and finicky process. For the most part you’d need to order a full panel putting the service outside of most hobbyists reach. Generating gerbers and drill files to the fabs specification could also be a process fraught with complication.

These days services that aggregate designs onto a single panel and break them out for distribution are common. For my work I mostly stick with OSHPark and SeeedStudio whose services complement each other well. I’ve also used Itead and found them compatible with Seeed (with the added benefit that they supply free boards for open projects).

Using OSHPark gives me the warm fuzzies. A child of the hacker community, born out of DorkbotPDX, all OSHPark’s boards are fabbed in the US (check out the great amphour interview for more details). Their services are limited to either 2 or 4 layer boards (always in purple, and always coated with gold (ENIG)), in 6×6 (6 mil traces with 6 mil spacing) or 5×5. I rarely attempt BGA boards so the 2 layer service works out great for me. OSHPark’s minimum order is 3 boards, which is perfect for prototyping. The gold plating also provides a nice finish, which both protects the board from oxidation and provides a nice surface to solder to. The main reason I use OSHPark however is that they’re cheap for small boards and have a relatively fast turn around (I recently purchased 3 tiny 20x15mm boards for $2.40 including shipping which was unbeatable). From OSHPark in the US to the UK my boards take about 2 weeks to arrive. They’ve also automatically upgrade boards to their super-swift service for free when there’s spare capacity. Their service is pretty slick, and provides a rendering of the gerbers prior to ordering as a final check which comes in very handy.

oshseeed2
Zigbee to esp8266 interface fabricated by Seeed (left) and OSHPark (right) (more complex boards here)

Seeed on the other hand are much cheaper for larger size boards and volume orders. They also provide more color and finishing options. The cheapest option at Seeed is green PCBs with HASL finish (hot air solder leveling). From Seeed, my boards usually take about a month to arrive (there are a few delivery options, but in my experience this is about as fast as it gets and faster shipping services often make using Seeed less attractive).

The image to the right shows a couple of very simple boards I had manufactured at both OSHPark and Seeed. I’ve never had a fabrication issues with boards from either service (though I prefer the ENIG finish).

Partly due to the limitations imposed by using commercial fabs I pipeline my projects. I send projects out to fab early in the design process and then switch to another design. When the board comes back I bring it up, bodge as required, and iterate over the layout. This works well with a two-week turn around, so I mostly use OSHPark while prototyping.

My boards also tend to be quite small (Arduino shield size or a little bigger). With small boards like this OSHPark is usually on-par or cheaper than ordering from Seeed (whose minimum quantity is 10 boards). With boards of about 100x100mm or larger I consider Seeed as they become significantly cheaper.

As a hobbyist I also rarely need huge numbers of boards, but for workshops when I need 10 or 20 boards I order from Seeed based on the final iteration of my prototypes. This is not only much cheaper than OSHPark, but I can get boards in a variety of colors to make workshops more interesting too.

This post has described some of the available options and my personal process. I hope it’s been interesting, but I’d love to hear about your favorite fabrication techniques, services and experiences both good and bad too. Please comment below!

41 thoughts on “Every PCB Has Its Place

    1. Dirty PCBs has a fervent following. But according to my tracking on http://PCBShopper.com, they are the cheapest manufacturer in less than 5% of the searches.

      Of course, those searches include small boards, where Dirty is very competitive, and large boards, where they are less so. It also includes people who are willing to accept fewer than 10 boards (Dirty’s Protopack deal does not guarantee 10 boards) and people who specify 10 or more boards.

    2. I have been using smart-prototyping.com, by far the cheapest for one up’s, supports many different board sizes, has all the options of everyone else, and v-scores

      just tossing it out there since the usual suspects always gets mentioned

      1. Moved from dirtypcb to smart-prototyping because they can have very short delays including shipping,and for the very responsive email support.
        But when lowest price is not mandatory and over one week is too long, Eurocircuit, for those in Europe, is really the best, their online board checker and configuration software is perfect.

        1. I agree about EuroCircuits (http://www.eurocircuits.com). They have an online design checker that shows any issues beforehand. After you order, you get a PCB “passport” that traces all the materials and chemicals used to produce the boards.

          They are not absolutely the cheapest, but so far the prices have been cheap enough that I have not had any reason to look elsewhere. The boards have arrived in about seven days, and I have not paid any extra for faster processing. On future projects, I’m going to try their more exotic boards (flex or semi-flex, maybe even IMS).

    3. I’ve pretty much switched to DirtyPCBs too – haven’t gotten a bad board from them, I’ve even used them for manufacturing. I alternated between Seeed and Smart-prototypes for a while, SP to get stencils – but I got a large batch of supposedly tested boards from Smart-prototypes that was full of shorts which turned me off of them.

      When comparing prices with Dirty PCBs compare all-up prices, their included shipping makes a difference – their cheap stencils without a frame is great for those proto boards you’re just going to make 1 or two with (just tape them on)

      1. For the frameless stencils I just lightly spritz the stencil bottom surface with spray glue, and wait a bit until it’s tacky. It’s pretty easy to get it stuck nicely to the PCB for paste application, and then peel it away. This works with mylar or kapton stencils, too. Don’t use too much glue or it’ll make the surface of your PCB messy during reflow.

  1. There’s a price comparison site for PCB manufacturing: PCBShopper.com. You enter your board’s specs and it puts up a table with prices and delivery times from Seeed, OSH Park, ITEAD, plus more – a total of 25 manufacturers including the best-known companies in Asia, North America and Europe.

    1. 2 weeks from submission to arrival in the UK for me. The tiny 2.40 boards were 2.40USD including shipping. For my orders I don’t think I’ve ever seen shipping broken out explicitly.

      1. OshPark does not charge shipping. They figure it’ll average out. Most boards are going to be several square inches. At a total of 2.40, your board was less than 1/2 sqin. I like that board house as well.

    1. I’ve also had great experiences with smart-prototyping. Shipping usually takes 7-10 business days when I select either “DHL China” or “DHL Hong Kong” (I can’t tell a difference between these two). Choosing any of the cheaper (by just a few dollars) shipping options resulted in delays of up to a month.

  2. I’ve been using DF Robot for a couple of years now. Pricing is similar to Seeed and DHL shipping is around $12. Using DHL instead of the $5 China post option, I get the boards about a week after I send the gerbers.

  3. I’ve been using http://www.elecrow.com for my PCBs, ranging from small “I’m too lazy to search for my perfboard” <$25 to "I think I just got a hernia picking up the box" ~$2000 orders.
    I had one minor issue with them rotating octagonal pads by 22.5 degrees (no shorts, but i needed to grab my magnifier to see the clearence), after which they offered to run a new batch, or give me a coupon for a few dollars off.

    The time between placing the order and receiving the PCB varies between two (shipping by DHL) and three (shipping by whatever) weeks. Free DHL shipping on orders over $300 is also a very nice plus.

  4. I had a $4~ board from OSH Park that took about 3-4 weeks from submission to arrival. I guess that’s what happens when you’re an electronics hobbyist in Canada, where all non-domestic orders take forever regardless of distance, and the only domestic options are super expensive as a result of a non-existent electronics industry.

  5. Making PCBs with a CNC machine doesn’t have to be expensive or difficult. I use mine routinely to make proto boards. I agree for any volume (10 or more) I send to a fab shop (iTead) but I’d never replace my CNC for the speed at which I can go from Eagle to bare PCB to soldered up proto board. I can knock out a new design in an afternoon. Try doing that with a board manufacturing service. My CNC machine http://www.mydiycnc.com/content/desktop-pcb-maker-system came ready to mill boards.

  6. I use iTead for my board. I’m not working to really high specs so the boards I make fit in nicely with their tolerances. All the orders I’ve placed have been checked and sent to manufacture within 1 day and they normally arrive in the UK in about 2 weeks (quickest 12 days, slowest 17 days).

  7. OSHpark makes really nice pc boards but I absolutely hate the purple solder mask. You can’t see through the base and it is hard to see the traces (on either side). It would be good if they had an option to select a lighter color.

  8. All those shops are fine but very slow and expensive for making prototypes. Usually you have to wait 3/4 week to have 10 PCBs. Once received, if you want to change something on the design start the cycle again. For that reason we have been working more than two years in a low-cost robot which makes PCBs at home and we are still researching about it.

    http://www.diyouware.com/

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