Micro Expanded Metal Mesh as Key Material for EMI Shielding

With the increase in electronic devices and the dramatic expansion of wireless communications, the problem of electromagnetic interference has become increasingly important. EMI may not only affect equipment performance, but may also affect communications, medical equipment, military systems, and other areas. Therefore, it has become critical to ensure that electronic devices can function properly in complex electromagnetic environments.

As an electromagnetic shielding material, micro expanded metal mesh is becoming increasingly important. It can help protect against electromagnetic interference and ensure equipment reliability. It has a lightweight structure, strong integrity, uniform surface, continuous and stable openings and flexibility to be customized.

Materials

Micro expanded metal mesh used as electromagnetic shielding mesh can be made from a variety of metal materials such as copper, aluminum, nickel, and Monel. Copper is the most widely used type. The copper content of our micro expanded metal mesh is above 99.7% (economical) and 99.9% (optimal shielding efficiency), and all of them are RoHS compliant.

Aluminum micro expanded metal mesh

Nickel micro expanded metal mesh

Copper micro expanded metal mesh

Specification

Reference specifications of common micro expanded metal mesh:
- Material: aluminum, nickel, copper, Monel or other materials
- Standard thickness: 0.05 mm or 0.07 mm
- Mesh opening: diamond-shaped holes
Reference specifications of copper micro expanded metal mesh:
- Mesh size (SWD × LWD): 0.3 mm × 0.5 mm, 1 mm × 2 mm, 2 mm × 3 mm, 3 mm × 6 mm, 4 mm × 8 mm (support customization)
- Thickness: 0.025 mm – 2.0 mm
- Magnetic field index: magnetic field: 450 KHz ≥ 55 dB; plane wave: 50 MHz ≥ 85 dB; microwave: 1 GHz ≥ 65 dB

Specification of Micro Expanded Metal Mesh for EMI Shielding
Item	Material	Thickness (mm)	Weight (g/m²)	Open Area (%)	Shielding Effectiveness (dB)
Item	Material	Thickness (mm)	Weight (g/m²)	Open Area (%)	100 MHz	1 GHz	10 GHz
BDES-01	Cu	0.05	215	53	72	53	33
BDES-02	Cu	0.07	245	64	60	42	25
BDES-03	Al	0.05	65	53	70	51	32
BDES-04	Al	0.07	74	64	58	41	23
BDES-05	Ni	0.05	214	53	60	46	28
BDES-06	Ni	0.07	243	64	54	40	24
BDES-07	Monel	0.05	271	53	67	53	36
BDES-08	Monel	0.07	395	64	63	46	30

Features

Stable mesh structure. One-piece mesh structure will not be loose or broken, the mesh surface is even flat, and has good durability.
Good electrical conductivity. Helps absorb or reflect electromagnetic radiation and exclude it from the protected area.
Heat resistance. Electromagnetic shielding can be guaranteed even in high temperature electromagnetic shielding environments or during heat treatment.
Non-magnetic. Effectively absorbs, reflects, or scatters electromagnetic radiation, reduces electromagnetic interference and leakage, and ensures the normal operation of equipment.
Corrosion resistance. Micro expanded metal mesh is usually made of corrosion-resistant metal, suitable for applications in harsh environments.

Application

Micro expanded metal mesh is widely used in scientific research, medical equipment, high-tech anti-electromagnetic interference engineering, aerospace, military and government agencies, and other environments that require electromagnetic shielding. For different application areas of electromagnetic shielding field requirements are different:

General civilian product chassis shielding effectiveness: ≤ 40 dB
Shielding efficiency of military equipment chassis: ≥ 60 dB
TEMPEST equipment shielding chassis shielding efficiency: ≥ 80 dB
Shielding room or shielding chamber, etc. often up to 100 dB

Faraday cage

Military shielding

A medical instrument protected by an electromagnetic shielding mesh compartment.

Medical shielding

Electromagnetic Shielding Mesh Selection Principles

Conductivity and permeability trade-off.
The electrical conductivity and magnetic conductivity of the material are critical to shielding effectiveness. The good conductivity of the material is suitable for electric field radiation sources, such as copper. The good magnetic conductivity of the material is suitable for magnetic field radiation sources, such as iron.
Conductivity and permeability trade-off.
Material selection should be based on the characteristics of the radiation source. For an electric field radiation source, reflection loss is larger, so you need to choose a higher conductivity of the material. For magnetic field radiation sources, shielding depends mainly on the absorption loss of the material, so materials with higher magnetic permeability should be used.
Frequency effects.
At high frequencies, the shielding mechanism depends mainly on absorption loss and has little to do with the nature of the electric or magnetic field of the radiation source. Therefore, the absorption properties of the material become critical.
Low frequency magnetic fields are difficult to shield.
Low-frequency magnetic fields (especially those below 1 KHz) are difficult to shield. Coping with low-frequency magnetic fields may require the use of highly electrically conductive materials, highly conductive materials, or even composites of both.

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