How to perform EMC shielding on the plastic casing of an edge box?

Edge computing boxes with plastic casings require surface metallization for EMC shielding. Common methods include:

1. Spraying conductive paint, such as silver or copper paint, with a surface resistance of <0.1Ω/□ and a shielding effectiveness of 30-60dB.

2. Vacuum plating or sputtering coating, which offers good uniformity and strong adhesion.

3. Pasting metal foil, such as copper or aluminum foil, which is low-cost but inefficient.

4. Incorporating conductive plastic and injection molding for one-piece molding, although conductivity is slightly lower.

During implementation, attention must be paid to ensuring continuity of conductivity at seams. Conductive foam should be added at the overlap of the upper and lower covers and compressed by 20-30%. The interface opening size should be less than λ/20, for example, for 1GHz λ=300mm, the opening should be <15mm. Eintech provides conductive paint and conductive foam solutions. Actual measurements show that spraying conductive paint on the plastic casing reduces radiated emissions by 18dB.