⚡ Electrical signal shielding

Relying on the high conductivity of copper. When an electromagnetic wave encounters a conductive copper layer, a portion is reflected and another portion is consumed by induced current (eddy current loss) within the copper layer, thereby achieving attenuation of the electromagnetic wave.

�� Magnetic signal shielding

Magnetic materials are required. Some copper foil tapes are coated with magnetic materials such as nickel on the adhesive surface to achieve magnetic shielding effect by guiding magnetic field lines.

✅ Typical scenario of single conductive copper foil tape

• Stick the copper foil on the inside of the plastic shielding cover - the adhesive surface is attached to the plastic (insulation), and the copper surface faces outward to contact the grounding spring, forming an electromagnetic shielding circuit.
• 360 ° surround shielding of the cable sheath - the copper surface contacts the shielding braided layer to complete grounding, and the rubber surface insulation will not cause short circuits.
• In the case of layered isolation to prevent short circuits between adjacent conductive layers, single conductivity is the only correct choice.

✅ Typical scenario of double conductive copper foil tape

• A conductive connection is required between two conductive casings.
• The PCB grounding pad needs to be connected to the metal frame to release static electricity.
• The gap of the shielding cover needs to maintain electrical continuity.

Copper foil purity

High purity electrolytic copper (Cu ≥ 99.95% -99.98%) is the foundation for ensuring conductivity. The higher the purity, the better the conductivity, and the higher the shielding effectiveness.

Copper foil thickness

Usually between 0.018mm and 0.05mm. Thickness affects conductivity, flexibility, and mechanical strength - thinner copper foils have better flexibility and are suitable for fitting curved surfaces; Thicker copper foil has higher conductivity and mechanical strength.

surface resistance

The surface resistance of copper foil is usually ≤ 0.05 Ω/sq. The lower the value, the smoother the current flow and the better the shielding effectiveness.

Shielding effectiveness (SE)

Expressed in dB. Above 30dB can block 99.9% of electromagnetic interference, and above 60dB is considered professional level. Single conductor copper foil tape can typically reach 55-88dB (100MHz-1000MHz) in specific frequency bands.

Adhesive force

Usually requires ≥ 1.0-1.5kg/25mm (180 ° peel test). If it cannot stick, the shielding layer will curl up and the signal will leak through the gap.

heat resistance

The conventional temperature resistance range is -10 ° C to 120 ° C. Copper foil itself is resistant to high temperatures, but the adhesive layer is the temperature bottleneck - high-temperature resistant products should be selected for situations that require reflow soldering.