Hilfe! PCB Etching in Deutschland

[fsaviator]

Frustrating...

I am coming to the conclusion that Ferric Chloride Solution for PCB etching is not available in Germany.  Can someone in Germany point me in the right direction for chemicals/process to etch PCBs.  I've used Ferric Chloride Solution before, so I'm familiar with it.  Is there something I can buy in Germany that does the same?

What is really annoying is that just printed a couple of PCB's and I have a bottle of FC somewhere that I brought over from the States with me but can't find it.

Thanks,

[Buster99]

Hello Warren,

Try this:
http://www.voelkner.de/products/289553/Bungard-Eisen-III-Chlorid-Loesung-fluessig-73131-01.html

I believe stuff mostly used now is sodium hydroxide or sodium persulfate
Those can be had at various online suppliers (Reichelt; Conrad; Voelkner, SMDV)

Hope this helps,
Best regards,
Marc

[fsaviator]

Great Marc!  Thanks.  Conrads has it!

I guess I'm headed downtown tomorrow.  I assume the process is similar?

Warren

[Buster99]

Hi Warren,

I would love to tell you but I have no idea.
While I have often read about etching and etching supplies I did not get a chance to try it for myself.
If it is a comparable Ferric Chloride solution there should be no difference in the proces but as always I would read the instructions and monitor the proces. Often fresh liquids may react better than older ones.
The Sodium mixes should work in a similar way by accelerated oxidization of exposed areas but may have very different reaction times, therefore I would closely monitor the proces and preferably use a test piece for trying. I also have no clue as to the toxicity of the stuff but would recommend proper ventilation and safety measures anyway!

Best regards,
Marc

[fsaviator]

So I'll throw this out first.  NO LAUGHING (especially Gwyn).

I was able to get some ferric chloride solution at Conrads this weekend when I went downtown for the Christmas Market.  I then proceeded to finally try and make a PCB.

I have decided I am taking my Prosimparts panels to the next level by making backlight PCBs for them.  Seems easy enough, and it will let me figure out how to do the process.  My VHF panel was first.

Here are the results of my test board.  Keep in mind that I fully expected to jack up this PCB so I continued on with it to the end.  It is not usable but my next one should be based on the lessons learned.  I'll fully document the next attempt in my build thread.

So I used the toner transfer method to print the pattern to the PCB.  Yes...  I figured out soon after I forgot to turn off the silk layer...  Oh well.  This method worked extremely well with my laser on some HP Brochure and Flyer paper I have laying around (HP Q1987A).  After ironing for about five minutes, and soaking for ten, it peeled right off.







Then I soaked it in Ferric Chloride.  This took way longer than I was led to believe.  Lesson learned, use more solution, and leave copper on those huge areas of PCB that are blank.  Still, very happy with the result (as you can see, leaving the silk layer on compromised some of the traces).



Now the fun starts.  I finally spent the time to get my CNC up and running right.  Not at the level of some in this forum but I am finally cutting with it.  I only broke three drill bits and a routing bit at the last moment.  that's why the final cuts didn't come out great, as I didn't want to waste another bit.  I had screwed the board down in two holes I drilled by hand, but forgot to exclude those holes in the g-code and the bit dove right into a screw.  Still, all things being equal, I am very happy with my first attempt at a PCB.



As I have the attention span of a 2 year old, I'm already off on a tangent.  I decided to 3D print a vacuum attachment for my Colt Router on the CNC...  threw one together in Autodesk Inventor, and it's printing now.  We'll see how that turns out.  Incidentally, if you haven't tried Autodesk Inventor, I highly recommend it.  You can print right to an STL that goes right to the 3D printer.  I got a three year educational license for free from Autodesk so it is great!

Stay tuned as once my LEDs get here, I'm going for the real thing.

[hexpope]

Well done with the PCB's. They look great ! and lol at the Silk screen, I think we all make that mistake at first. I am just wondering tho, with the CNC machine, why didn't you just route out the PCB using that method ? that what I do and it turns out really nice.

[fsaviator]

Thanks!

Good question on using the CNC for the PCBs...

I haven't really looked into using the CNC.  I guess it would be fairly easy.  Diptrace can output to CNC so that shouldn't be a problem.  What type of bit would I need?

[phil744]

You know warren for a first attempt thats actually not to bad.

You made me laugh about the screw versus the endmill, i do that everyday, seems like screws are magnets for endmills.

Trick you may want to try is to put large ground planes on the board, basically areas of nothing on the board, fill it with a large copper plate connected to ground.  For a backlighting board dont really matter ifs grounded or not, just try and avoid etching off massive pieces of copper.  Yoe end up with a massive imballance of etch, i.e. big areas take ages to etch, and small tracks are over etched and usually dissapear.

Other option is something called thieving, in short is just a shit load of dots not connected to anything, just to avoid etching massive areas of copper.

At work me make board by the millions, so time to etch is critical for us. and i do this for my own backlighting PCB, norlayy they take 70 seconds to etch.

keep at it, looks like your well on the way

[Buster99]

Hello Warren,

Nice PCB's and great to see that the etching worked out fine!
For the engraving I would use an engraving router bit, v-shape, something like this http://www.ebay.de/itm/like/390075013746?lpid=91&_configDebug=ViewItemDictionary.ENABLE_PAYMENTS_IN_HLP:true
I do believe that this only works on a properly designed layout where only a little of the copper has to be removed. For large area removal I think the etching method is much more practical and economical. Your CNC router also wears out faster when constantly running for such trivial tasks.

Edit: I see that Phil744 already posted some better info on designing the boards than I can provide.

Best regards,
Marc

[fsaviator]

Thanks Phil and Marc.  Good points.

I realized about 20 minutes into etching that I should have used the option to keep the large areas of copper on the board.  As you said, I could tell that some of the traces were over etched.

My next one will go that route.  I'm also toying with trying the CNC for cutting the PCB but after watching some videos I have to admit that etching is definitely better looking.  I'm very surprised that I hit on the perfect paper first try (and I have a ton of it sitting on the shelf), and my laser worked great.

I'm currently using drill bits for the component holes and fishtail diamond routing endmills for the cutouts.  I've got v-shaped engraving bits to cut traces when I try that.

[sagrada737]

It's hard to beat the PCB shops for convenience, speed in turn around, and quality for turning our ideas into printed circuit boards.  I use ExpressPCB here in the US. 

Services like this may seem a bit expensive for only a few pieces.  But if you consider the convenience, it is hard to duplicate the same product at home when making complex, or multi-layer PCBs.  Once you try a service like this, it is hard to go back to tying to do it yourself.

Mike

[fsaviator]

Mike,
I used one of those services for the PCB for my Garmin530 GNS I built four or five years ago.  They are a great service, and it was worth it back then.  I checked them out again but just not economical for one-offs of multiple different boards.  US based companies are also hammering me on postage now.  USPS pricing just doesn't hack it anymore with everyone using UPS and FEDEX in the US.

I already have the software and hardware, so really, the cost boils down to the boards, etchant, bits, and time.  I can make a simple dual sided board for under $5 and it will do whatever I need it to do.  I can also instantly fix mistakes and I can reuse a board right up until I drop it in the etchant.

Warren