Having PCBs made.

I'll be watching with interest Dave. Before Christmas I thought a future project would benefit from a custom PCB and started looking at this lot

My project has taken a different course with more being done in software and what hardware I need can live on a prototyping shield fitted onto the Arduino.

My PCB experience dates back to black tape on mylar and being spoiled with a wet PCB process where I worked to get home jobs done usually the same day. Sadly not available to me now I'm retired.

For me the learning curve of mastering PCB cad and interfacing with a PCB house keeps driving me back to vero board or similar until I really have no other option.

Bob

I have used PCBtrain a lot and I am happy with the quality and service. The Express service is useful if you can live without soldermask and is relatively inexpensive. I use EasyPC to generate the Gerbers. DesignSpark from RS is a free cut-down version of EasyPC. RS provide DesignSpark library models for many of their products.

John

John

I recently made a project that required an interface board to sit on the GPIO of a Raspberry Pi and have a 1602 LCD display sit on the other side.

A design for a double sided PCB was provided and I went as far as ordering the blank PCB and a bottle of FeCl3, but reality kicked in, because the design was far more intricate than anything I had etched before, not to mention that I've never attempted a double sided board, so I didn't even start.

Instead I got some of that double sided board that's a bit like veroboard, but isolated copper lands, not strips. I soldered the 0.1in headers, tact switches etc and hand wired the board with thin PVC covered stranded wire salvaged from a CAT5 patch cable. The insulated wire is thin enough to pass through the holes.

Stranded wire makes for sounder soldered joints when the joint is made on the print side rather than passing through from the other side due to capillary action. (IYSWIM)

I am pleased with the result, it's no bigger than the specified PCB and for a one off, took me a lot less time than it would if I had tried to reproduce the artwork and etch one, and that's assuming I succeeded.

I was spoiled back in 1991, where at work I had access to electronics CAD and a flat bed Gerber file driven photoplotter that took anything upto A2 (or was it A1? - a huge machine) sized sheets of negative film, and exposed a aperture controlled light source driven across it via a X-Y table mechanism. This was in a specially constructed photographic darkroom, so film went next into tanks of developer, fix and wash - and out with a perfect negative for later UV exposure onto resist pre-coated copper fibreglass board. Finally that sloshing round warm ferric chloride in a pyrex dish balanced on top of a hotplate - Ah, I can still smell the fumes. Not too many 'home jobs' though. No time :-(

I've made my own PCBs from scratch in the past. And have things like a heated bubble jet tank for etching and a pukka UV lightbox. But have found it difficult recently to get suitably dense black on the transparancy. Nothing like as good as I once got years ago.

I've always designed by boards just using a draw programme - rather than a proper PCB design one. As it only has to produce a life size transparancy. And I use the same CAD prog for lots of technical drawings - the devil you know being easier to use than learning afresh. The latest version of the CAD prog I'm using can produce gerber and excellon files, so now I've got a better idea of what those are can produce the same drawing that gerber and excellon can be made from.

Although I eventually migrated to tape and/or a Letraset like method (Alfac, I think) and UV box, all my early boards from the mid 60s - usually one offs - were made like this:

Draw track layout on 0.1" squared graph paper, then cut laminate to size and fold graph paper tightly round it, securing on the back with masking tape.

Take a very sharply pointed centrepunch and mark the location of every hole on the copper through the graph paper. Carefully remove graph paper for possible re-use.

Take a bottle of nail varnish - dark colours preferred although black wasn't in vogue in the mid 60s! - and use the supplied applicator brush to paint the track pattern, using the centrepunched marks as a guide.

After etching and resist removal, drill board as required at the centre punched marks.

You can't get more DIY than that!

They're likely a fair bit cheaper. The main difference with PCBtrain is they have a variety of different processes you can pick from, while Ragworm is much more limited.

If you're not in a hurry

That's not really a bad option. You can almost certainly do it quicker that way, unless you hit limits like:

- size constraints

- number of layers

- plated through holes

- signal integrity

- awkward-pitch SMD (1.27mm SMD is doable on padboard)

- need >1

For the times when you do want a PCB but don't want to wait for a fab roundtrip, I've been pondering non-etch ways - if there's anything less messy than the ferric chloride method.

Theo

The way I read the website they make several designs on the same sheet so c an fit them in optimally - I'm sure it's a fairly large sheet, too. I and others at work used PCB Train and apart from one board where the plat ed through vias had a problem (copper a little too thick so the resulting h ole a bit undersize) everything worked fine. If you don't need solder resis t the express service is good and reasonably cheap, too. Not relevant to th is discussion but we also used their assembly process - I really didn't fan cy assembling 100 boards with nearly six hundred components on each - and f ound that was fine, too

In this case, only a few will be built initially, and the rest as required. The cost comes down per unit for bulk, so it made sense to buy more than enough PCBS in one go, as they don't take up much space to store. And I quite enjoy building such things - although probably not 100. ;-)

I opted for the three week service to save costs - there's no rush.