Copper foil from ebay

[prasimix]

I'm wondering if any of you have an experience with thin copper foil as one marketed here.

What is the difference between "single" and "bidirectional" model/type?
Is it possible to solder e.g. a wire to such type of foil? If not, does something else exists that is solderable?

[langwadt]

yes you can solder to copper foil, I'm guessing bidirectional means conductive adhesive

[prasimix]

Thanks. The price difference between single and bidirectional is minor. Therefore I can give a try to bidirectional but still would like to know what does it exactly mean.

[chemelec]

Possibly means Sticky on One or Both sides?

[prasimix]

Yes, that's possible 

[mikerj]

Is it pure copper, or copper covered aluminium which seems to be a Chinese specialty?

[cdev]

If you have a roll of copper tape, how can you tell? I have noticed occasional strange phenomena with my (adhesive on one side) copper tape's conductivity which made me wonder hearing that.

Is it pure copper, or copper covered aluminium which seems to be a Chinese specialty?

[SeanB]

Odd things with copper tape are often due to the thin top film used to reduce corrosion. If overlapping the tapes best is to solder the seam every so often to get good electric contact between them, either just a solder spot or use some wire soldered both sides.

To test if it is copper, CCA or plated steel use first a magnet, which will attract the steel. Then apply heat from a cigarette lighter, the copper will glow red and not droop, and the red surface will be noticeably softer when cold, and a lot easier to bend. CCA will melt and droop. Have not yet met copper plated nickel sheet, though it must exist, as an intermediate process to doing a full chrome or gold finish for things that are formed in a press from sheet or strip. Probably the cost of the base nickel is close to the cost of copper, so not a thing to fake.

[cdev]

Thats been my experience, that it sometimes needed to be soldered. Contact wasn't enough.  Sometimes it is and sometimes it isn't.

[Bud]

Being sold as "Guitar pick up foil", thay may mean the sound can "travel in the tape"  only in one direction or for the "bidirectional" flavour of it in both directions   . Audiophools certainly know that.

[prasimix]

Being sold as "Guitar pick up foil", thay may mean the sound can "travel in the tape"  only in one direction or for the "bidirectional" flavour of it in both directions   . Audiophools certainly know that.

Huh, this is a good one .

[Mechatrommer]

then you tell me how it can improve anything by taping it on the guitar's body? will it sound better than curt cobain's guitar?


and it can protect from slug and snail as well, maybe due to some type of earth resonance?...


https://www.ebay.com.my/itm/Guitar-Pickup-Copper-Foil-50mm-x20m-Shielding-Screening-Tape-Conductive-Adhesive/362431461195?hash=item546299374b:g:1kYAAOSwl75ZuIbI:rk:12:pf:0

joke aside. i think i will be interested at getting one of this (not for audiophoolery) but i believe there is clear lamination on top of the copper to avoid oxidation. i dont want it i want naked copper that we can directly solder on. if anybody know an easy way to strip that off with some chemical that will be interesting. one application is gluing it to a specified dialectric material (ceramic ptfe anybody?) so we can make our own RF grade pcb or such, RF pcb on the market is audiophoolery grade of price.

[coppercone2]

how to tell: sand paper should do it. Just rub on it with sand paper till you get through to the paper side, it should at least tell you if its plated. As for if its electrical copper? No clue, resistance measurement maybe.

[thermistor-guy]

...
joke aside. i think i will be interested at getting one of this (not for audiophoolery) but i believe there is clear lamination on top of the copper to avoid oxidation. i dont want it i want naked copper that we can directly solder on. if anybody know an easy way to strip that off with some chemical that will be interesting. one application is gluing it to a specified dialectric material (ceramic ptfe anybody?) so we can make our own RF grade pcb or such, RF pcb on the market is audiophoolery grade of price.

I bought some adhesive-backed tapes - kapton, copper, polyester - to experiment along the lines you mention. E.g. a low-impedance, flexible, cut-to-shape power bus with kapton/copper/kapton/copper/kapton layers.

I also bought a silver (conductive) ink pen, to see how practical it is to make a small-ish circuit on layers of tape. Punch holes in the correct tape layers (different pattern for each layer), draw the traces on each layer, let dry, stick the layers together, add ink to connect the layers, let dry. Ink in the component pads, add components, let dry. Connect the pads to traces, let dry. Result: a low-cost multi-layer flexible PCB with good rf properties. As many layers as I want.

It's only an idea at the moment, but I have uses for it if it works.

[Mechatrommer]

I also bought a silver (conductive) ink pen, to see how practical it is to make a small-ish circuit on layers of tape....Ink in the component pads, add components, let dry....
It's only an idea at the moment, but I have uses for it if it works.

no it wont work. i have silver conductive ink it too fragile to hold anything even a single strand of wire, it will peel off, have done that. it only usefull at connecting broken traces. or you may glue your component with something else before tacking it with the ink. it might work never done that.

[cdev]

Kapton makes a great insulator and it withstands high temperatures, the problem is that its so thin that whatever the impedance you would get using it is likely to be unsuitable for RF.

My guess is that it likely has a fairly high dielectric constant.

As far as printing circuits (in an additive way) There is a group at Georgia Tech that has done a lot of research on printing things like RFID antennas (To power sensors using RF in the air) with conductive ink, and a lot of their research is on the web.

You know that does work okay as a substrate for RF circuits is foam core/foam (double sided sticky) tape. And its likely fairly low loss. But very solder unfriendly -

Another widely available rigid material thats easy to work with is cardboard. Ive built a number of antennas using combinations of copper tape, cardboard and aluminum foil.

[thermistor-guy]

Kapton makes a great insulator and it withstands high temperatures, the problem is that its so thin that whatever the impedance you would get using it is likely to be unsuitable for RF.

My guess is that it likely has a fairly high dielectric constant.

As far as printing circuits (in an additive way) There is a group at Georgia Tech that has done a lot of research on printing things like RFID antennas (To power sensors using RF in the air) with conductive ink, and a lot of their research is on the web.

You know that does work okay as a substrate for RF circuits is foam core/foam (double sided sticky) tape. And its likely fairly low loss. But very solder unfriendly -

Another widely available rigid material thats easy to work with is cardboard. Ive built a number of antennas using combinations of copper tape, cardboard and aluminum foil.

Hmm, I have a bunch of old business cards in good condition. Maybe I could punch them out to form a honeycomb pattern, and stack the cards inbetween tape layers (kapton or copper or ...)., to get the desired thickness/impedance, ideally forming a near-air dielectric.

 I can't help thinking there are some useful possibilities here, for low-cost prototyping. Some experimenting and testing required, obviously.

[GigaJoe]

bought have this tape.  it copper, no coating, solderable, very thin, expensive. often sell as guitar shielding ..

[Mechatrommer]

bought have this tape.  it copper, no coating, solderable, very thin, expensive. often sell as guitar shielding ..

the link the OP provided is cheap tape in a roll version. there is another china version 30cm x 20 cm about less than $5 per sheet. and then there is another "dupont pyralux" type (you can find in ebay) that is real expensive. are you talking about the china cheap version in the OP? or the pyralux version? the china version seems too good to be that kind of shiny uncoated. wait... here is the pyralux... https://www.ebay.com.my/itm/Pyralux-Kapton-Flexible-Printed-Circuit-Board-Material-Various-Models-9-x-12/153153567548?hash=item23a8a9fb3c:m:mZd9yxPw_PT3JDsXBsOafTw:rk:4:pf:0

[BurningTantalum]

I have used the cheap Chinese version in 4mm (?) widths. It solders OK if one is quick about it, and the glue is very sticky. I surrounded the bottom of my house walls (70 metres) with two runs of it spaced about 6mm apart, connected to an HV generator. This was the only way to stop a biblical invasion of Portuguese millipedes. The tape has lasted for 3 years without peeling off.
BT

[Mechatrommer]

i'm thinking of gluing it to some plate, apply etch resist ink and then etch it in FeCl, just as normal diy pcb making, is it doable?

[glarsson]

and it can protect from slug and snail as well, maybe due to some type of earth resonance?...

No, not earth resonance. Snails and slugs just can't stand copper and will not travel across it. Must be bare copper; no plastic film to protect the copper.

[bloguetronica]

then you tell me how it can improve anything by taping it on the guitar's body? will it sound better than curt cobain's guitar?


and it can protect from slug and snail as well, maybe due to some type of earth resonance?...


https://www.ebay.com.my/itm/Guitar-Pickup-Copper-Foil-50mm-x20m-Shielding-Screening-Tape-Conductive-Adhesive/362431461195?hash=item546299374b:g:1kYAAOSwl75ZuIbI:rk:12:pf:0

joke aside. i think i will be interested at getting one of this (not for audiophoolery) but i believe there is clear lamination on top of the copper to avoid oxidation. i dont want it i want naked copper that we can directly solder on. if anybody know an easy way to strip that off with some chemical that will be interesting. one application is gluing it to a specified dialectric material (ceramic ptfe anybody?) so we can make our own RF grade pcb or such, RF pcb on the market is audiophoolery grade of price.

Snails don't like copper and copper salts that result from natural oxidation because it is toxic to them. There is also the hypothesis of them being "electrocuted" by copper, but I don't buy that. The chemical reaction seems more plausible.

Kind regards, Samuel Lourenço

[tggzzz]

and it can protect from slug and snail as well, maybe due to some type of earth resonance?...

No. It doubles the natural Reiki homomorphic crystal frequency, thus interfering with the snail's vision. That encourages them to go elsewhere.

[thermistor-guy]

...
Snails don't like copper and copper salts that result from natural oxidation because it is toxic to them. There is also the hypothesis of them being "electrocuted" by copper, but I don't buy that. The chemical reaction seems more plausible.

Kind regards, Samuel Lourenço

Makes sense. Apparently, copper sulfate also kills algae. Copper compounds are used in some pool/spa cleaners: http://lochlor.com.au/company-profile