Fritzing, Gerber and UK PCB Houses

[Hippogriff]

I downloaded and started playing with Fritzing earlier. I've really only just noticed that the time is nearly 02:00 now and I'm about to go to bed, finally. I've really enjoyed learning today. The software is pretty cool (I'm a first time user of something like this) but there are a couple of "gotchas" - for example, I didn't want to use the Breadboard layout, but it seems that is where all the wires (nets) are stored, and how it sychnronises the other views (Schematic and PCB), you can't delete these in the Schematic or PCB view.

Anyway, once I got that into my head it was all good fun.

I've been messing around with RGB LED strip projects a lot recently, I've always been using Veroboard to get the final output... works fine for me, I thought PCBs would be outside my limits, but it seems that may not be the case... everyone can get in on this these days.

So, I've done my schematic... power 2-way header (no DC socket yet), MAX667, capacitor, a 14-pin PIC and then 2 x ULN2003ANs, before heading out to a 10-way header... it might not be perfect, but - hey - I'm pretty pleased with it.

Then I went into the PCB view and I've finally got all that stuff onto a 61mm by 52mm rectangle - I think (actually I'm pretty sure) that I could do better with the layout and still save some space, but this was achieved with the Fritzing auto-routing function successfully coming back with everything connected fine.

Now I'm almost too excited to say, I want to find out how to save these as Gerber (I assume?) files and then send them off somewhere to do me a short run - say 10 or so.

So, after all that... bearing in mind I'm in the UK and this is my first ever time of trying this... is there someone out there who can recommend where I should go for this... maybe a place that can handle newbies like me? Cheap would be good. Quick would be great. Mutual-exclusivity ignored of course!

I would love to hear from anyone who has first-hand experience of doing this from the UK - small PCB, short run, er... simple stuff (single-sided, nothing clever here)... I saw https://www.pcbtrain.co.uk/ and I've heard of BatchPCB (US, I think?)... nothing like a personal recommendation, though.

 

[colin mac]

Now I'm almost too excited to say, I want to find out how to save these as Gerber (I assume?) files and then send them off somewhere to do me a short run - say 10 or so.

File > Export to gerber
exports extended gerbers and the NC drill file.

Then I went into the PCB view and I've finally got all that stuff onto a 61mm by 52mm rectangle - I think (actually I'm pretty sure) that I could do better with the layout and still save some space, but this was achieved with the Fritzing auto-routing function successfully coming back with everything connected fine.

Just make you've accounted for the space the components might take up when they're in the board. Really you should only try to make the PCB as small as possible if it's really necessary. PCB houses often have a minimum area they charge anyway.

 

[Hippogriff]

Oh, this could be a lot of smaller, there is a lot of unused space still - but the whole idea of having a PCB (for me) is twofold - 1, it should be smaller than what I do on Veroboard and 2) reduction in soldering requirements.

That said, I still don't know anywhere good (all of reliable, quality and cheap) to send this for production. Any advice?

 

[colin mac]

Oh, this could be a lot of smaller, there is a lot of unused space still - but the whole idea of having a PCB (for me) is twofold - 1, it should be smaller than what I do on Veroboard and 2) reduction in soldering requirements. That said, I still don't know anywhere good (all of reliable, quality and cheap) to send this for production. Any advice?

Use the price calculator here for a quote.
https://www.pcb-pool.com/ppuk/order_productconfiguration_js.html
They're good in that if there is a problem with the design, you'll be notified before it's made and given a chance to fix it.

 

[Hippogriff]

Ah, that's good to know. Thanks.

For my little single-sided single-layer PCB it comes out at €10.47 each for 5 of them. Is that about the best price I'd get from somewhere reputable? I'd probably not want to order more than 5 straight off the bat, I have to build up confidence in this first.

Do I need soldermask? Is that what makes it green?

Do I need silkscreen? Is that what allows writing and stuff?

I genuinely don't know.

Look at my little PCB from Fritzing... I mean, it's the simplest thing ever... see what I mean about there being some leftover space? I'm sure I can finagle things around a little bit, but I'm more interested in kicking something off... I think I'm about ready to take a punt on having my first PCB created...

**broken link removed**

P.S. - the site you pointed me to, they take Fritzing files as-is, it seems.

 

[colin mac]

You don't need silkscreen, it's just a simple board with few parts. Soldermask will prevent corrosion of the tracks. It's up to you if you want it. It is usually green.

What size the drills and pads? You should have at least a 0.2mm annular ring.

 

[Hippogriff]

What size the drills and pads? You should have at least a 0.2mm annular ring.

I don't really know what that means. I haven't set anything specific while using Fritzing, I've taken default values for things and just moved them around then hit the "Autoroute" button. When I click on a mounting hole on one of the components in the PCB view of Fritzing, I see settings of "hole diameter" of 0.086 and a "ring thickness" of 0.02 - units appears to be inches.

0.02 inches = 0.508mm... so that should be OK?

 

[alec_t]

Does Fritzing allow manual re-routing after auto-routing? I ask because, given the free space you mention, some of the tracks seem unnecessarily close together and risk solder-bridging so could benefit from manual routing. Also, why the double tracks running under the PIC ?

 

[Hippogriff]

Yes, it does. I've not played much with that yet. It didn't feel... intuitive. You move one thing and loads of other things move and it gets messy, quickly.

I had noticed the double tracks connecting things to ground more than once, seemed unnecessary to me, too. I guess I could mess around with this.

 

[Hippogriff]

Actually, it was much more intuitive once I forced myself to use it.

Does this look better? I even put a narcissistic 'copyright' on it... even though I don't think I'll pay €17 for silverscreen.

**broken link removed**

 

[colin mac]

It looks fine but if you want to attach the gerbers and drill here I can check it properly for you.

 

[Hippogriff]

OK, that's really cool. I did an "export" to Extended Gerber (RS-274X) from Fritzing and I got the following files:

18/07/2011 19:55 401 Fader3_contour.gm1
18/07/2011 19:55 4,842 Fader3_copperBottom.gbl
18/07/2011 19:55 1,464 Fader3_drill.txt
18/07/2011 19:55 2,204 Fader3_maskBottom.gbs
18/07/2011 19:55 108,961 Fader3_silkTop.gto

Which I'm hoping are the files you need, and then I've put them into HippoPCB1.zip here...

I hesitate to ask but... how can you check it properly?

Let me know if that's not the stuff you wanted.

 

[colin mac]

There were no errors. Minimum spacing on your PCB is 0.4mm. Minimum annular ring is 0.5mm. Min track is 0.6mm.
PCB house typically want gaps and tracks no smaller than 0.2mm and an annular ring no less than 0.2mm.

One thing though, the copper layer is set as the bottom layer. You've designed the PCB as if the copper layer is the top. If it was made as the bottom, pin 1 wouldn't be what you want, because it's the bottom as viewed from the top.

I have gerber editing software. Don't know any that's free

 

[RichTheDude]

Hi Hippo,

Glad to see some UK people doing electronics, we seem a rare breed now!

I have used PCBtrain lots of times, so far they have been ace, letting me know of any problems they have before they manufacture. There is cheaper about, but they have always been good .

They do an express service, which is 48 hours (if you order before noon, it will be there not the day after, but the day after that) - 2 layer plated through holes, no silkscreen or solder resist. You can get small boards for £30 (without delivery or shipping).

Solder resist (mask) is like a green paint so to speak, it will stop corrosion of tracks, but more importantly it will stop solder flowing, something which really helps hand sodlering surface mount devices.

Everything on your PCB is 0.1 inch pitch or greater, so to be honest - I would not bother paying extra for solder resist or silkscreen.

I have heard Spirit Circuits will do such a board for free (their Naked service), but I have not tried them myself but I know of people that have.

Also I always use GC prevue to verify the gerber files - If you want, download it, install and import your gerber files (**broken link removed**). I then save this and include the GCprevue file (*.gwk) as most board houses I have used will use it as a reference as to how the board should turn out.

The PCB package I use never gets the drill sizes correct ., I always have to fix the NC drill file.

Hope this helps, tried to think of every pitfall I have almost tripped over in the past

 

[Hippogriff]

Thanks very much for checking that out for me! That stuff you said about PCB Houses is good to know.

One thing though, the copper layer is set as the bottom layer. You've designed the PCB as if the copper layer is the top. If it was made as the bottom, pin 1 wouldn't be what you want, because it's the bottom as viewed from the top.

Gah! I don't know how to remedy that... I just created my schematic in Fritzing, then moved to the PCB view (which gives you all the components, ready to go) and I went and put a "rectangular PCB" component on the page then started autorouting. I didn't set any layer order or anything. I've looked through the menus and I can see options to turn off the viewing of layers, but not the ordering them or anything like that.

Do I have to start from scratch?

 

[Hippogriff]

I have used PCBtrain lots of times, so far they have been ace, letting me know of any problems they have before they manufacture. There is cheaper about, but they have always been good .

Excellent, that about PCBTrain and the other feedback is really helpful. Thanks!

 

[colin mac]

edit - actually nevermind its ok . if its made as the bottom and you put the components through the top, it's alright.

 

[Hippogriff]

Gee, I'm stumped by this to be honest. Forgive my ignorance, I know it can be frustrating when people don't 'get it'...

I haven't a clue how to flip everything and I'm perplexed as to why I might need to. I thought, as my board was single-sided and single-layered, that it would be child's play to get something that would work almost out of the box. Well, you know what I mean.

I didn't, therefore, even think it even had any layers. But it does, obviously. All those orange connections are on "copper bottom layer" and that's where they always were when I moved into the PCB view from Schematic view. If I hide that layer then I just see the white text, "silkscreen top layers". The "copper top layer" is actually greyed-out, i.e. unselectable. It only becomes available when I set the PCB to be two-layers, double-sided, which I don't think I want.

I can rotate things, but that's definitely not the same as flipping them.

Isn't it simply the case that my 7 components would go into the PCB the way that I'm looking at it? Component legs go into the holes, I solder them on the other side, and then everything connects up via the copper tracks, whichever layer / side they're on? Or, if I did that, would nothing connect up at all?

Am I missing something so obvious?

 

[Hippogriff]

edit - actually nevermind its ok . if its made as the bottom and you put the components through the top, it's alright.

Oh, I'd not seen this. Am I back on track?

 

[colin mac]

Yeah, sorry about that brainfart I had there.