Idea: Aluminium Oxide PCBs and Redox

I had this crazy Idea of how we could use Aluminum sheets of a certain strength for PCB production. Aluminum oxide is a very good Isolator and is already used as high temperature PCB base material.

The basis idea is this:
An aluminum sheet is baked till it consists of mainly aluminum oxide.
it should look like that...

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Oxide
------------
Aluminium
------------
Oxide
------------

We must find a sheet thin enough that the layer can be grown to a sufficient strength. This could be easily done with electrolysis.

The next part would consist of redoxing the 2/3 half of each layer back to aluminum. I know of no process which could do this without destroying the sheet or be done without too much trouble but maybe we could come up with something...
assuming we have done this we would have

------------
Aluminium
------------
Oxide
------------
Aluminium
------------
Oxide
------------
Aluminium
------------


Now we could either try to mount a hot flame on a reprap and try to oxidize the insulating part of the PCB or find a material which sticks to the aluminum well enough and withstand the electrolysis process.
The middle aluminum layer could be used as common ground so we could go even farther than with traditional double layer PCBs..

hmm I probably should have posted this in the Electronics Sub-Forum

Edited 1 time(s). Last edit at 06/10/2011 02:16AM by ElectricMucus.

... aluminium is a bad material for DIY-electronics, as the 'natural' oxide on the surfaces will prevent soldering

Because of this and the much easier etching processes copper is the mostly used material ...

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Well I must admit I haven't tried soldering alu but what about sanding it before the solder?

If there could be a process found aluminum cans could be cut, flattend and used.
I came up with the Idea because I tried a jet lighter on a can and I got a nice white spot of oxide on it...

There is no way you are going to solder to aluminium not matter what you do to the surface. The chemistry doesn't work.

Well that's what I thought until Forrest said he could solder aluminium with ordinary solder, so I tried it with foil, and you can. I think the main problem is if you try to solder anything thicker it sucks the heat away.

Edited 1 time(s). Last edit at 06/10/2011 05:39AM by nophead.

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[www.hydraraptor.blogspot.com]

... for connecting to solid aluminium you can use conductive epoxies and i made some tests with laser-fusing, but you need high laser energy-densities ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

It is possible to solder aluminium. I have used special aluminium solder and it does work but it does not run and flow like on copper. You have to rub it in and it often won't take well. I cant imagine it being at all practical to attach electronic components too.

It can be spot welded easily though. That's how aluminium wires are joined to things in motors. A micro automated spot welding system of some kind might work.

That gives me an idea.

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Quote

It can be spot welded easily though. That's how aluminium wires are joined to things in motors. A micro automated spot welding system of some kind might work.

That gives me an idea.

Make your Mendel twice as accurate.

That's an awesome idea, do you mean attaching a piezo on the head and ultrasonically weld the feet of the smd components? (That would need to be pretty damn accurate but you could weld several feet at once though)

I think this could even work for a copper pcb.
But both techniques could hypothetically eliminate the costs of a pcb (except the redox chemicals, assuming something like that even exists)


I found something new: [www.elmhurst.edu]

As it seems using copper chloride you can create a copper layer on aluminum, but will it stick?

Edited 1 time(s). Last edit at 06/10/2011 07:21AM by ElectricMucus.

Aluminum soldering is similar to Aluminum welding it requires a slightly diffrent flux you can use standard solder with not so good results. I sure I'v seen some recently I think it may have been Maplin.

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I don't know how this could possibly be used to advantage, but it sounds fun anyway.

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I don't know how this could possibly be used to advantage, but it sounds fun anyway.

[www.popsci.com]

Well we could use it as a very fancy way to create layer masks.

But seeing this I think my Idea is pretty worthless since as it seems as long as aluminum oxide can it stays that way.

The best thing I could come up with is using a reactive gas & a high voltage source..

Aluminum oxide is sapphire and ruby (when doped) It is really hard and can be brittle. The chips work well as sandpaper though. Semi-precious gems too. Also useful for watch bearings.

Do not know why it would be better than FR-4. Glass is silicon di-oxide, the fibers are used to make fiberglass, so there is not really that much advantage of an alternative.