What is copper foil tape used for?
Copper foil tape is used for EMI / EMC shielding. EMI is electromagnetic interference, unwanted electrical noise radiated by one circuit that upsets another. EMC is the discipline of making sure equipment neither emits too much of it nor is disturbed by it. A conductive foil wrapped around a cable, seam or enclosure gives that noise a path to follow instead of letting it radiate.
The Mr.Bond® product is coated with an electrically conductive, pressure-sensitive acrylic adhesive, which is the important detail. With a conductive adhesive, overlapping strips of foil are electrically joined through the glue line, so the shield stays continuous across a seam.
It is specially designed for EV application, at 65 to 70 micron thickness, and it passes the 2-point test method and bears a temperature range of T2. It is typically ordered with insulation materials from the wider group range at Lalit Jain Industries Pvt. Ltd. (LJIPL).
Why does the adhesive need to be electrically conductive?
An ordinary acrylic adhesive is an insulator. If you shield with a foil tape that has a non-conductive adhesive, every overlap becomes an electrical break in the shield, and the shield is only as good as its worst joint.
The conductive, pressure-sensitive acrylic adhesive on this tape removes that break. Current can pass through the adhesive from one layer of foil to the next, so a spiral wrap on a harness or a taped seam on an enclosure works as a single shield.
Pressure-sensitive means the tape needs only firm hand or roller pressure to bond, no heat, no solvent, no curing time on the line. The corollary matters on a shielding job: a conductive adhesive pressed lightly onto an oxidised or anodised surface gives a poor electrical joint while looking well stuck, which is covered along with the rest of the specification checklist in copper foil tape for EMI shielding and grounding.
What do the 65 to 70 micron thickness and T2 rating mean?
65 to 70 microns is the quoted thickness of the tape. A micron is one thousandth of a millimetre, so this is a thin, conformable foil that can be wrapped around cable bundles and pressed into corners without fighting back.
The tape passes the 2-point test method and bears a temperature range of T2, the two qualification figures quoted for this grade. When you enquire, send the substrate, the width and the temperature your assembly reaches so the right grade is confirmed for you.
Shielding is one of five jobs tape does inside a battery pack; the EV battery tapes hub sets out the others and the material used for each.