I'm not very good at predicting what's going to appeal to a wide audience, so I experiment. A few months ago I blogged about the 'engineer's emergency kit business card'

That post got about 70,000 visits within a couple of weeks and lots of love from HackerNews, Hack a Day and others. This was a pretty damn good indicator to me that there's interest in the concept ;) A few weeks later I decided to experiment by creating a product that is based on this card.

It's called 'the tiny engineer superhero emergency kit'!

The concept was to create a novelty yet useful kit that's packaged like a product that you'd see on a high street shop and that could be given as a gift. I wanted to use this kit to test the market for novelty kits for engineers (not necessarily to test if people are generally interested in kits -- we know that they are!) 

The kit includes the PCB (ENIG finish), NPN MOSFET, two resistors, capacitor and LED that when soldered create a working circuit (the LED lights up). There's a guide card, and something I haven't seen done before: a laser cut and engraved compressed cellulose sponge.


I came up with this idea after deciding on the small tin can, and thinking about how to make it useful during the assembly of the kit. Having access to a laser cutter at our local Makespace, I experimented with engraving and cutting these sponges. This took a significant amount of time and material to get right -- but it ended up looking fantastic. As you can see in the picture, the "burnt" bits disappear when the sponge is wet and expanded, giving them an ephemeral nature, which I really like. When expanded the sponge fits snugly in the tin and can be used for cleaning the iron while soldering!

This is what it looks like when soldered all soldered up (complete assembly instructions are here).

When power is applied the LED turn on


But of course one could patch the board to change the circuit. There are two extra slots for resistors and six pads for SMD components.

For scale (board measures 37 x 37.3 x 1.6 mm)


Right. To business. You can get this lovely kit over at our shop for an introductory price of £16 for this first batch of 300. For every one of these sold, Boldport will donate 50p to the Inkscape Fund. Inkscape is an open source SVG editor and is an integral part of our design process with PCBmodE, so this is my way to thank the wonderful Inkscape devs!

As usual, the design is open source hardware -- get it here -- and make your own version!

Please provide feedback and help spread the word! :)

A Boldport board manufactured by Cambridge Circuits

"Where should I send my board to?" comes up quite regularly in conversation. I'm actually not the best person to ask. The reason is that when I have boards made I'm looking at more than just functionality, and my demands are typically pretty unique (much to the frustration of CAM engineers, I'm sure). Also, my boards typically do not push the limits of the technology, so I can't say a whole lot about quality in 2+ layer boards, controlled impedance, very fine pitch pads, super thin traces, etc. Still, my experiences -- please take them as such -- may be of value to some.

We should first distinguish between two types of services: "standard" and "pooling". With a standard service the boards are made for you on a panel dedicated to your design. Regardless of the amount you'd order, there will be a one-off "tooling" cost added that mainly covers the creation of mask sets that are used to produce the panel. (If you re-order the board with no changes, there will typically be no tooling cost.) A pooling service adds your design to a panel shared with other designs so that the tooling cost is also shared and becomes a part of the unit price you're quoted.

Pooling is cheaper if you're ordering a small amount of units.  But because it only makes financial sense to the producer if there's a large volume of designs, it is typically only available in a limited set of "stackups" (board thickness, soldermask colour, finish, etc.). Sometimes you'll just need to compromise in order to get that reduced cost. (Note that you should add the tooling cost to the amount charged for the boards when comparing prices.)

Notice that I did not quantify what is "small amount", and you'll see that I won't quote prices either, just deal with those qualitatively. The reason is that it's a moving target with too many variables to be meaningful in the long-term. What I write today may not apply tomorrow when a fab changes their service (for example, a pooling service going ENIG finish as default, or a service now offering free shipping worldwide). My suggestion is that based on what you learn from this article, you should get quotations from a few services and compare them for an actual design with the actual quantity you need.

Here's a summary of fabs I've manufactured boards with in the past year. (These are all boards that I've designed with PCBmodE, btw)

Eurocircuits, EU, pooling/standard
Beta Layout, EU, pooling/standard
Express Circuits, UK, standard
Cambridge Circuits, UK, standard/local
P+M Services, UK, standard/local
Ragworm, UK, pooling
OSH Park, US, pooling
Hackvana, China, standard
Tinyosshop, China, pool?


Below are my experiences with each.

Eurocircuits

Eurocircuits is a Belgian company that has fabrication facilities in Hungary and Germany. It appears to me that most of their business comes from their pooling services since they constantly invest in tools to make the process easier, which ends up reducing cost for us. Their ordering process and browser-based "design checker" is great for catching last minute issues and can save time by not needing to wait for an "exception" report from an engineer. Eurocircuits' pooling pricing is one of the best I can find in the EU and their pricing engine is comprehensive and it's very useful to be able to play around with it in order to find a good cost break point. It's definitely worth giving it a go. (They also produce great videos showing their manufacturing process.)

If I wasn't fussy about how my boards look, Eurocircuits would have been at the top of my list of go-to fabs. However, I find that for most of my board I cannot use them. They insist on having their production number added to the board for identification. Some of my instructions are often ignored, and I also found that their response time is painfully slow when things don't go smoothly through their automated system. But let me repeat: most people won't encounter the problems I've had with Eurocircuits and as long as you don't care much about the looks of your board and things go through their automated system, the value is excellent.

The 'cuttlefish', manufactured by Eurocircuits. Notice the different colour of soldermask coming from their two fabs in Germany (top) and Hungary (bottom).

The top side of 'cuttlefish'. The bottom one is the prototype run (notice Eurocircuit's number placed inconviniently in the visual focal point of the board). The top one is the production run, where the number is placed at the bottom, with some silkscreen fixes.

Beta Layout (aka PCB-POOL)

The 'emergency business card' and 'engineer superhero kit' are board without soldermask and silkscreen, made by Beta Layout.

A German/Irish company that predominately offers a pooling service. Their ordering system is less robust than that of Eurocircuits, but you do get a similar result, which is an immediate quotation for your board. They currently offer ENIG as default and, in some cases, a free solder paste stencil, which is a neat bonus if your board happens to require it. They accept an impressive amount of file formats which could mean fewer possible exceptions which translates into faster delivery. I have only used Extended Gerber with them, though.

The 'superhero' board made by Beta Layout

There are two things I like about Beta Layout that make them my current go-to more-than-a-few-pieces manufacturer. Firstly, they allow me to not have silkscreen and soldermask at a reduced cost and still be pooled (this came in handy for the business card and emergency kit). Secondly, their customer service has been phenomenal so far. They call me to clear up problems right away, they are responsive, and they even made 'superhero' for free just so I can see the results in physical form after I pointed out some issues! They genuinly go to lengths to make things work out to my satisfaction, and that's a big plus for me. I'm currently expecting my first board with them that has soldermask and silkscreen to come through, and I do hope it comes out well, so I could continue sending boards their way.

Express Circuits

The 'lifegame' is a huge panel made by Express Circuits

Express Circuits is a high-end UK manufacturer. I've used them in the past, before PCBmodE, and one of their senior engineers has been really helpful in giving me feedback on the Gerbers PCBmodE produced earlier on. Express is not a pooling service, so you're going to see a fairly high tooling cost, and they do have a high minimum order limit. However, you do get quality service and quality boards with any customisation you require. For example, soldermask colour is not a factor in pricing, so you can define any RGB colour and they'll mix it! I made the large wall-mounted circuit art 'lifegame' with Express, and am now waiting on a new design from them, on top of two other designs I haven't mentioned publicly yet. When I need a custom job that requires special attention to detail and that crosses their minimum order amount, Express is where I go. It's a pleasure working with a high-end manufacturer, but it does cost more.

The back side of 'lifegame'

"Local", Cambridge Circuits and P+M Services

The 'wuther', lovingly manufactured by P+M Services for the Wuthering Bytes workshop

I put Cambridge Circuits and P+M in the same "local" category. These are the fabs that are close to where you're based. There are a few good reasons for using a local shop: they tend to be super friendly and informative, which counts for a lot; you can visit the shop and get to see and feel some samples of their work in order to get a good idea of how your board is going to come out; they accommodate customisation; boards can be done quickly -- they are sure to accommodate fast turnaround -- and you can go pick them up to save on the shipping time (and cost); and, it feels good to give business to a local provider. Doesn't it?

A design beautifully manufactured by Cambridge Circuits

The down side, of course, is that it's going to be more expensive than the pooling services or, sometimes, than the larger outfits. That's understandable, though in many practical cases cost isn't the main factor in the decision. Another thing to consider is whether the local fab can accommodate your "production" run. If it cannot, it might be worth doing the prototype runs where you're going to go for production so that there are fewer chances for surprises.

Ragworm

Ragworm is a relatively new pooling service operating in the UK and is a division of the larger Stickleback Manufacturing. They offer a distinct orange soldermask and pretty standard default stackup. They promise to deliver the boards within ten days -- shipping is included in the price -- and their pricing is decent if you're making just a few boards. If you're in the UK it's certainly a service to try.

An early prototpe of an educational board made by Ragworm. Notice the randomly placed logo and name added to the design

What bothered me with Ragworm was receiving the boards with their logo in silkscreen randomly slapped on my board! There's no mention of this on the ordering process, though I'm told that one can ask for their logo not to be added (as I did the for 'redditoken' shown below). I found their customer service to be quite good and responsive, and also heard from someone who made their first board through them that they were very helpful in guiding her through the process.

The 'redditoken' made by Ragworm (bottom) and OSH Park (top), each with its trademark colours. Notice the registration misalignment on the Ragworm version (some of the OSH Park ones also had similar issues). It's the same design but with a completely different look!

OSH Park

The 'oshwart', made by OSH Park. Notice the breakout tabs and the slight misalignment of the silkscreen on one side -- this is within OSH Park's spec.

OSH Park is a US-based service that operates a submission system that cleverly optimises designs into panels that are sent to be made by a few select US-based manufacturers. OSH Park boards have an ENIG finish and a distinct purple soldemask. Pricing is simple with free worldwide shipping with a slick ordering process that lets you see the post-processed Gerbers, which is a great as a last opportunity to check for problems. Price-wise OSH Park is very attractive for a low quantity order, typically beating similar services on price alone.

The 'shimmy', made by OSH Park.

However, in my experience, boards can arrive up to a month from the time I placed an order using the free shipping option (I'm in the UK!) I take that into consideration when ordering board from them, and I rarely need boards quickly. Sometimes I cannot use OSH Park due to the lovely purple soldermask since traces don't show through, which takes away one visual dimension that my boards require. The boards arrive with the fasteners that hold the pieces to the panel still attached, and filing them off can take some time and is a bit messy; other pooling services typically provide boards completely and neatly routed out of the panel. Finally, Laen, who runs OSH Park is very technical and passionate about his work and providing quality service, and so when I want custom work within his constraints he accommodates and is open for exploring new ideas. This is great resource for experimenting cheaply.

The 'deadwood' board made by OSH Park. The copper that's masked is very hard to see without just the right lighting

Chinese manufacturers, Tinyosshop and Hackvana

I've used Hackvana and Tinyosshop for small trial runs with the Chinese manufacturers they work with. In both cases, unfortunately, the boards were not to the standard I expected. Personally, I'd rather pay a bit more and have a direct relationship with the manufacturer and avoid surprises when boards come back. Keeping it close to home and not dealing with language barriers has its advantages. For these reason I no longer even consider Far East manufacturers. This may changes until I can justify getting a top tier manufacturer. These are very anecdotal experiences and personal preferences, I admit, and I accept that one can get great (and cheap) boards from Chinese manufacturers if one cares to experiment.


As you see, there are quite a few factors to consider when choosing a fab house, and there are many more that I did not even mention! My final recommendation is to try out a few fabs when there's an opportunity in order to test their ordering system, support, and, of course, quality. Every fab will have its quirks, which you only discover when running boards through them for a while and decide whether you can "live" with them or not. There's no short-cut to a fruitful relationship, and this is no exception.

(Please add your thoughts and experiences in the comments!)

Back when electronic components were large and circuit board technology was in its infancy, clever engineers used the 'cordwood' construction to save space. We rarely need that sort of assembly method any more, but when I first saw it, I thought that it was a beautiful example of form meets function in engineering.

The Cordwood Puzzle lit up

I had to make a tribute that combined old and new, and it comes to you in a form of an engineering puzzle!

Packaged as a kit

In order to save costs and make things interesting, I wanted to have the two boards be exactly the same. I designed the board and circuit such that its function depends on its position, and how it is connected. That's part of the puzzle that you'd need to figure out when putting the circuit together ;)


The 2 W resistors are used for their size, not their power rating. The three coloured LEDs are 2.1 V so that you'd only need one resistor value (150 Ω) to drive each of them at 20 mA. This simplified the circuit compared with using other colours, and also gave the board some flair even when it is not powered up. There's an n-channel FET for each LED, where the gate is connected to a pin and pulled high through a 10 KΩ resistor (it's a high value so that whatever drives it only sinks a tiny bit of current). This means that when power is applied to the circuit all the LED turns on, but the state of each LED can also be controlled from a microntoroller.

Each LED can be individually controlled

And if you like it, you can get one for yourself at the Boldport shop! The BoM is here and the (strangely missing ;) assembly guide is here (SPOILER ALERT!). As usual, the design is open source hardware -- get the files from here and make your own version!



The Cordwood Puzzle is based on a previous design codenamed 'deadwood' that I did months ago, but never really documented. It was manufactured through OSH Park with many components kindly donated by oomlaut. The design files are here, and below are some pictures.

It's possible to use regular resistors

I originally found these beautiful resistors at Makespace

These lovely colourful LEDs came from oomlout!

It's hard to see, but there are copper hexagons under the soldermask

Rows of shiny domes on the 'cuttlefish' board

I'd like my boards to look and feel the best as they can, particularly for photos. I invest a lot of effort and attention in the detail and look of my boards, but that's not enough if the end result, components and all, does not look as polished.

The Cordwood Puzzle

When I solder through-hole components, I will typically cut the lead, or anything poking out, together with the solder blob as close to the board as possible using flush cutters. (Using flush cutters is important since regular cutters taper in for the cutting edge, which does not allow cutting as close to the board as needed.)

Any through-hole pad can be made to be smooth. This is a board from Tom Hartley.

You'll be left with a rough surface that needs to be touched-up with an iron. Sometimes that's all it takes, but often you'd want to add some solder to create a nice dome. If it didn't work out, cut off the abomination and redo.
When I'm happy with how the solder points look, I clean the burnt flux with Flux Off. The board can become a bit sticky after that, so give it a good clean afterwards. You now have a beautiful board with smooth solder points!
In the video it looks more laborious than it really is once you get used to it. The one thing to be careful of is to not cut off the soldermask when cutting off the blobs!

BAM! There will be no mistake that you're a fucking good engineer and you know it!
This plaque comes in three different custom, unique, colours: red-orange, light-blue, and green-yellow. These are meant to be close -- but not quite -- to the traditional red, green, blue that you'd see on other, ordinary, boards. This way, it still looks somewhat like a PCB, and not something else. The boards are ENIG coated and shine like a charm when light goes through them.

This is the second edition of this plaque. We've only two made two for the first edition, and one of them was won at an auction by oomlaut for £105!  For this second edition of the plaque we made 50 of each colour. Each plaque is numbered, signed, and dated by myself.

Please don't let four letter words distract you from what's unique in this board! The familiar electronic symbols span several layer stacks to compose the complete symbol. This is a unique feature that I haven't seen done before.


Ready to tell the world you're fucking good at what you do? Get the plaque from Boldport's store!

(Oh, as usual, this board is open source hardware. The files are here, and I'd be happy if you make some for yourself and others!)

I love using things for what they were not intended for. Often it doesn’t quite work out, but I had a good feeling about this next one. I woke up on the wrong side of the bed one morning and saw my girlfriend's hair straightener staring at me. My one track mind -- circuits! -- immediately realised the potential in this commoditised el-cheapo piece of kit, even for someone, like myself, without much hair to burn!

I spent a few hours researching hair straighteners. What I needed was:

* Floating plates are springy in order to have even pressure on the hair. Since for my use I wouldn't press the plates together, I was concerned that they wouldn't be quite parallel so would heat the board unevenly. Being able to press one end on each plate would give me more flexibility.

* Temperature control is essential with some of the cheaper hair straighteners having a fixed temperature setting (not good!). The best range I could find is 150°C -- 230°C which is within the reflow of low temperature solder paste. All good.

* A locking mechanism is useful for fixing the plates into place. Some allow locking at various positions. The one I got locks "closed", but still has a wide enough of a gap.

* A long swivelling power cord seemed like a good idea.

* A stylish carrying case.

I decided to go for the Remington S3500 Ceramic Straight 230 Hair Straightener; street value of £15. (I expected both plates to be "floating", but only the bottom one is, but it turned out not to be an issue since the plates are parallel even with a 3--4 mm gap.) Here's a video of the process and results



I'm quite pleased with the outcome:


It's certainly not a replacement for a reflow/toaster oven, but could find its use in some cases such as a localised soldering job to avoid melting other bits, etc. Also, it's mobile.

What do you think?

Press releases go out tomorrow, but I've been permitted to write about the news today for the loyal readers of this blog: Apple acquired Boldport! We've been negotiating since January and have finally gotten the deal through.

Steve Jobs famously insisted that every bit of Apple's products look good, even the circuit boards that the consumer will never see. Beautifully functional circuits -- Boldport's tagline -- is a natural continuation of this concept, where circuit boards are designed with emphasis on both function and form, and are celebrated on their own right, not necessarily hidden behind cheap plastic enclosures. Thus, Apple is the right place for Boldport to continue its growth and a great vehicle to realise its vision.

Starting immediately I'll be sharing my time between Cupertino and London and will be leading a newly established group that's dedicated to realising the vision I started out with. This vision will be applied in practice through products made for Apple's triumphant entry into a new market. Sadly, I cannot say more than that at the moment.

A bit of sad news is that I've had to agree that PCBmodE -- the software we developed to create our circuit boards -- will become an internal Apple tool and no longer be an open source project. However, I'm still able to sell Boldport's products until stocks run out, so get your beautiful circuits now!

A new era for Boldport begins today!

Know that sinking feeling right after realising that you've soldered that 40-pin header on the wrong side of the board? I know it too well. When that happens you either need to chuck out the board or re-work it until the pesky thing submits to heavy use of heated force. The result is often ugly and most likely results in a lifted pad, which makes the soldering of another header -- the right way round this time -- harder.

I've come up with a technique that works for me for removing the wrongly-placed header, and here's a video of me executing this circuit surgery:




The advantage of this technique is that it doesn't require any special equipment. What you'd need is a soldering iron with a pointy tip, tweezers/pliers, flush cutter, and a solder wick. The trade-off is that you will need to sacrifice the header in order to save the board. Here's the procedure:

1. Cut the pins on the back side as close to the board as you can
2. Cut the pins on the top side close to the black holder
3. Using pliers/tweezers/flat screwdriver, gently lift the black holder from the pins until it's completely removed
4. Using a pointy soldering iron tip, heat the flat pads on the back side and push the pin by inserting the tip into the hole in the board. If the pin doesn't fall off use pliers to pick i
5. Use a wick to extract the excess solder from the hole. If needed, use the pointy iron tip to get the solder to stick to the pad and clear the hole

That's it! Watch out not to damage other components with the iron or hot wick. Also, make sure that the iron is hot enough for rework and never press too hard on the iron so that the pads don't lift.



Do you have any other re-work techniques?

By now, when I look at components I evaluate their aesthetics as much as I do their functionality. When I design boards, the look and feel of the component has to fit the design, not only what it's supposed to be doing. Resistors come in an amazing spectrum of colours -- particularly older ones! -- and I wanted to find a way to use them for their colour rather than their value.

I had a bunch of resistors -- 1/8W and 1/4W -- left over from a project and I wanted to experiment with a symmetrical arrangement.


A week or so ago it was raining and I found refuge at a Maplin. Looking around I found an amazingly colourful resistor pack, and I made this piece with its contents.


The base is made of a soda can. I found it to be just the right thickness for the job, although a copper foil might have been better for the square piece. I experimented with a bunch of methods for fixing the resistors in place while still having bright 'background' colours.

What I've done is to set the resistors in regular acrylic paint. That meant that they are attached to each other through a common base, but can still move a bit for final adjustment. Then I attach the resistor 'pack' to the metal base with epoxy and apply acrylic on the top to fill in all the holes and get an even coat (that needed to happen more than just once). When it's nearly dry I soak the whole thing in water and peel off the paint that's on the resistors -- this didn't work quite as well as I had hoped. You'll notice that some of the resistors are battered from the numerous peelings.

Finally, I apply a transparent acrylic pouring medium to create the 'dome' and give it a shine. You'll notice that there are bubbles and some 'cloudy' areas in this dome -- I'll need to figure out how to avoid that from happening.

There's still work do be done to get these things to look perfect, but as a first go I'm happy with the results. Imperfect as they are, each goes as a gift to one of the two women in my life ;)

Hello everyone!

With the new Boldport website design this blog has moved to:

  http://boldport.com/blog

and the shop to

  http://boldport.com/shop

Please update RSS feeds, links, etc.