Ferrite Tape

[JimMetalsCeramics]

Does anyone know where I can buy ferrite tape? I assume this is magnetic ceramic ferrite particles in an adhesive binder?

 

[plasgears]

Contact 3M, the tape people.

 

[kenvlach]

3M spun off their magnetic storage media division into Imation (

http://www.imation.com)

about 10 years ago.
Not much scientific info on their site, the media on their storage tapes is referred to as 'MP' and 'thin film.' MP is metal particulate, thin film is evaporated metal.

http://www.imation.com/assets/Global_Assets/Products/PDF/DLT_Flyer.pdf

I believe that oxides (magnetite, CrO₂, barium ferrite, etc.) are less commonly used nowadays due to improvements in creating ultrafine metal particles and thin metal films.
For magnetic tape technology (a bit dated), see
Magnetic Tape Storage and Handling:

http://www.clir.org/pubs/reports/pub54/

For samples, maybe start with cassette or data storage tapes.

 

[JimMetalsCeramics]

The ferrite tape is an adhesive one. It is apparently used to buffer inductive coupling between an electrical board (e. g., a PCB) and underlying metal.

 

[kenvlach]

Does it have to contain ferrite?
McMaster-Carr (

http://www.mcmaster.com/)

sells various types of EMI/RFI shielding foils & tapes (copper foil, copper mesh, lead, etc.), a silver-containing acrylic latex coating($$$), adhesives and conductive sheet, etc. Just enter EMI in the 'Find Product' box.

 

[JimMetalsCeramics]

I imagine that in order to buffer the induction you have to create a magnetic gradient in response to the incoming RF signal. I doubt that more metal (even though it's dispersed in the tape body) would do the job. The induction is through the magnetic field coming from an induction coil on the PCB. I think I've heard that you can only buffer a magnetic field with ferromagnetic material.

 

[kenvlach]

Presume by 'buffer' you mean shielding. Check out the mumetal foil (on p. 3392 in McMaster-Carr):
"Nickel Alloy Foil
Protect electronic equipment from RFI, EMI, and magnetic interference that can cause failure and false signals. This soft-temper MU foil is made from a nickel-iron Alloy (80% nickel) that's easy to cut and hand form. Conform to ASTM A753-85 Alloy type 4. Width tolerance is ±.005" for 4" width; ±.010" for 15" width. Adhesive-backed foil has a pressure-sensitive adhesive on one side."

I believe ferrites are for things you want to magnetize ('hard' magnetic) whereas for shielding you use something 'soft' magnetic. Hope that helps.
Ken

 

[JimMetalsCeramics]

Thanks. I sent out some email.

 

[IRstuff]

http://www.ferrishield.com/

makes square ferrite tiles

TTFN

 

[TChronos]

McMaster also has a variety of self adhesive magnetic tapes and sheets. Just do a search for "Magnetic Tape" on their website:

http://www.mcmaster.com.

 

[transistorman]

Jim,
Did you end up finding a supplier of ferrite tape? If so, I would be interested in knowing who it was. I am also in need of such a shield.