PCB Copper Panel Plating Through-Hole / Via Tutorial

[ivantessmer]

I just started platting PCB in copper. What would you guys all recommend I buy to not get the damn sulfuric acid on me!

[shades2]

Nice trick with the bags.

[koofel12]

@PatheticComputing Hi, don't you think that 10 g/L of PEG is a bit too much? I've just done the plating solution and added 10 g/L of PEG 6000 to it. I plated at around 7.6A per sq foot for an hour (I know the current is a bit off 10A). The plating seems to be a bit weird, in some places 0.6mm holes seem to be a bit clogged by copper (although they seemed to be quite fine after hole activation - ink + graphite).

[PatheticComputing]

@koofel12 The PEG concentration that I used is based off the MG Chemicals copper electroplating solution which in the MSDS states 1% PEG. That's all I can really say about that. I actually haven't tried holes less than 0.8 mm. But, I have had good results with the solution.

[MiShO10O0O]

Why don't you plate the holes after etching ?

Isn't there a way to copper plate chemically without using electricity ?

I think if there is ,, It would be easier to etch your board first , Then use this conductive ink to cover the holes and just plate it . I'm sorry I don't know a lot of chemistry :D and sorry for my bad English :D

Nice video btw

[PatheticComputing]

@MiShO10O0O It is possible to plate copper without electricity but it is more difficult, involves more exotic chemicals, and leaves only a very thin plating. Sorry, but as far as I know, there is no easy way to plate after etching the board.

[PinutTUBE]

I'm now trying to do that! what is inside the copper electroplating solution exactly?!? (dosage)

[gneu01]

@PatheticComputing Hello,

Thanks for your kind answer. I could make my first conductive via pcb without problem.

I have another question. Is the distance between the anodes and the cathode (PCB) important? What is the minimum distance ?

Best regards

[dtiydr]

I dont understand the use of hydrochloric acid when you clean the board? The sandpaper would be more then enough by it self.

[ONixaO]

isn't it better if you first etch the board and then plate the holes???

[gneu01]

Hello,

I watched your video with great interest. Great job!!!

I have questions about the polyethylene glycol.

1. I have it in the laxative powder form. I like to know how much I have to put in the solution. I guess that I need first to dissolve it in water. How many g/ml? Then pour some ml of the dissolved polyethylene into the plating solution. How much ?

2. Do I have to add polyethylene glycol in the plating solution for the next job.

Thanks best regards from Belgium.

[KaranSoin]

Very enlightening tutorial. Just a thought about etching, will it work if we etch before electroplating ?

[PatheticComputing]

@KaranSoin This question has come up a couple of times. I don't think so because the problem with trying to plate after etching is that you no longer have an electrical connection to the holes which you need in order to plate the holes.

[rapsod1911]

And how about using SMD solder paste? You fill all holes and re-flow it. Maybe for better result put short piece of wire in every vie.

[PatheticComputing]

@rapsod1911 I suppose it could work, but you would have to make sure that the solder only stays in the holes. Also, I have not tried liquid tin.

[johanliem]

Amazing tutorial! Thanks for the video!

One question: what is the purpose of polypropylene filter? Is it necesary to be there?

[PatheticComputing]

@johanliem Not really. When you electroplate, a thin film of black sludge forms on the anodes. I think the filter is supposed to keep the sludge from getting into the solution, as well as other contaminants from the anode. But, I don't think it's necessary if you're doing low volume plating.

[Jarni1979]

How about using copper powder instead of graphite?

[PatheticComputing]

@Jarni1979 I haven't tried copper powder. I played around with making conductive ink last year and I tried aluminum powder but it was a failure. I was going to get some copper powder but I never did it.

[Jarni1979]

@PatheticComputing

You can easily make copper powder adding aluminium foils to a CuSO4 solution and adding a spoon of NaCl. Hot reaction and copper powder will precipitate but the problem is to dry without oxidate it.

I'm triyng to make a copper based paint, using styrene I got good results but I'm looking for a better resin.

P.S.

The ink you use is real ink or acrilic paint? From the video I can't understand very well. My english isn't so good.

[PatheticComputing]

@Jarni1979 The bottle says it's waterproof pigmented acrylic ink.

[PatheticComputing]

Thanks for 10,000 views!

[DaMrBob]

Nice video !

I'm too awkward manipulate ink without having my hands black after ;)

So I found another solution to replace graphite+ink : silver conductive paint, it can be found at farnell/newark : Electrolube SCP03B.

Much easier to apply and it dries quickly without hot-gun. Apply it on one side of a hole, it goes through the PCB by capillarity, then after ~20 seconds just blow out the excess until you can see through the hole.

How much voltage do you apply to your copper plating tank ?

[PatheticComputing]

@DaMrBob Yep, silver conductive ink/paint is a better way to go *IF* you have the money. If you want to coat a larger board with hundreds or thousands of vias, then the ink/graphite mixture will be cheaper but it is not as conductive as the silver based ink.

I'm using 5 volts for electroplating.

[mrshitaake]

Are all of the copper bars except the middle one connected to Vcc and the middle one is GND ?? Im not sure if im getting this right.

[PatheticComputing]

@mrshitaake You are correct.

[siwastaja]

Hi, many thanks for the tutorial; I tried it and it worked like magic the first try!

I also came up with a way to protect the copper surfaces from the paint; I use a standard hot laminator and standard laminating pouches to laminate the cleaned PCB; then I drill and apply the paint using a squeegee -- only very little paint is needed; then I remove the laminate (apparently it doesn't leave a trace!), cure in oven, clean quickly with HCl and plate. Quick and easy with less scrubbing.

[PatheticComputing]

@siwastaja Hello! Glad to hear that it worked for you! I have tried using laminating sheets but my laminator is so crappy and it doesn't properly fuse the sheet to the board. Would you mind sharing what brand of laminator you are using?

[siwastaja]

@PatheticComputing I'm using a A3 size office laminator I found for 30 EUR from a supermarket... I think it's one of those branded with different names for every bargain. I agree that the sheet is not perfectly fused to the board but enough to protect from the ink. I'm using black acrylic paint so it doesn't seep into very small gaps (BTW, had to mix abt 80% graphite 20% paint to make it work). You can try spraying a little bit water to the PCB to make it slightly moist to help lamination?

[Racius19]

Hello, I tried your tutorial, but I am not sure about few things.

What hardness should I use for the graphite ? I sanded some black lead from pencil, but my feelings are that it is too hard.

Then I am not sure about the function of the PEG and the acids. Could you shortly explain it ?

The highest result I reached is that thin and very spongy layer of copper was created near by the PCB copper layer, but it didn't go through. It is also very weak, I can scratch it with my finger nail.

Thank you

[PatheticComputing]

@Racius19 I just bought some fine powdered graphite from ebay. The PEG acts as a suppressor. I'm not sure of the science behind it, but it should decrease the size of deposited copper grains and make the deposited copper more level. And, I've seen other copper plating solutions use it (e.g. MG Chemicals solution). The sulfuric acid increases the conductivity of the solution. The hydrochloric acid acts as a brightener.

I would try reducing the current. Use the formula and stay below 10 ASF.

[Racius19]

@PatheticComputing

Thank you.

Well, my bro' brought me some fine graphite from school laboratory. I'll test it.

1 amper for small board was so brutal, I reduced it for few miliampers and then it was better, but not ideal.

[ohmikron1]

I'm building an agitator/PCB holder for the plating system rather than a magnetic stirrer because the filter envelopes would foul the stirrer. It will provide a good connection to the copper laminate and shake the board up and down in the solution. That should be enough to prevent the formation of bubbles on the surface. Maybe I'll post a video of the thing when I get it working.

[PatheticComputing]

@ohmikron1 Sounds promising. I'm interested in hearing how it turns out once you've completed it. Keep up to good work!

[ejoe001]

Ahh - I see, the oxide is soluble by HCl - of course !

This is what I mean - I´m a roockie in chemistry.

In your video you mention Polyethylen Glycol 3350 in your plating solution.

Because I don´t know were to get this right now, I have found a replacement here in Germany, they have used polysorbate 20 instead.

Can you tell me what is the function of Polyethylen Glycol in your Plating solution as well ?

Thanks again ...

[ejoe001]

Thank you very much for this clear video.

I start electroplating my next boads because of this.

I will take tenting foto resist further on.

Question: You use hydrocloric acid for cleaning the board after activating it.

But as a "non chemical":

Isn´t it useless to drop pure HCl on a copper layer.

The copper won´t be etched by pure HCl - am I right ?

What for you use HCl ?

[PatheticComputing]

@ejoe001 I'm not sure what you mean by non-chemical. I use the HCl for cleaning boards because copper oxide is soluble in acid. You are right in saying that the copper won't be etched by HCl alone.

[refa42]

Have you tried placing a protective film on the board before drilling and then taking it off after activating the holes? It might help the process. And could 'liquid tin' be used as a etch resist or do you specifically want to use non-proprietary stuff?

[PatheticComputing]

@refa42 Yes! Using a protective film is something I'm playing with right now and I got the idea from watching a LPKF video. I haven't tried using liquid tin but if it can plate to a sufficient thickness then it may work. I've used TINNIT but the etchant would almost instantly eat it away. Also, remember that you need to use an etchant that doesn't attack tin like H202+H2SO4. Let me know what happens if you try the liquid tin.

[refa42]

@PatheticComputing Oh ok. I guess Liquid Tin, Tinnit, and tons of other brands are pretty much the same stuff, all of which are electroless plating solutions so thin layer is what you get. So much for that idea then.. just a thought. There are commercial resists and also gold plating so something will work.

I'm planning to use hydrochroric acid, H2O2, and also bubble tank as a etching bath. Actually it doesn't matter as long as it's not ferric chloride.

Anyways, good stuff. Keep it up! :)

[jedavis1947]

To protect PTH when etching: After holes are plated apply photoresist to card. Expose so that the traces and pads are open to solution. Plate card with tin or solder. The PTH will plate also protecting them. Etch as usual. Tin/solder plating is an etch resist. Bonus is that you get the pads and traces tinned.

[jedavis1947]

More thoughts. The plating setup: If you coat the copper and solder joints with lacquer it will not corrode. You don't need to solder the rods. There is a simple clamp designed to attach two rods that are at right angles. Plater's tape is great for wrapping the parts you don't want affected.

[PatheticComputing]

@jedavis1947 Good idea, thanks! I actually have some conformal coating that should do the trick!

[jedavis1947]

Well done tutorial.  You speak at a slow rate and there is no distracting noise in background. Good sourd and the image is in focus. Wow! Regarding the technique, the hole activation applies graphite in a binder to the hole. This remains after the plating, between the copper and the fiberglass. When you solder a wire in a hole, a lot of heat is applied. The binder may break down causing a the copper to separate from the fiberglass, losing support. I don't know this is a problem.

[PatheticComputing]

@jedavis1947 Thanks for the comment! I was thinking if I used a thick enough plating on the holes then there wouldn't be a problem. I haven't actually used any of the boards that I have plated yet so I'm not sure yet. I'm still trying to perfect this since the plating is still very thin. I think I need to agitate the solution with a magnetic stirrer like they do in the MG chemicals method.