Study On Preparation And Measurement Methods For Mesh Metallic Materials Of Electromagnetic Shielding And Plasticity Absorption Shielding And Absorbing

In recent years, China has made many relevant laws and regulations onelectromagnetic compatibility indexes; therefore, domestic R&D personnel forelectromagnetic compatibility products need to improve their knowledge andunderstanding of the concept of electromagnetic shielding. Many electronic productsfail to consider the problem of electromagnetic compatibility during the design,development and processing, which leads to the fact that many products cannot passthe compulsory electromagnetic compatibility tests as required by foreign countries.As a result, corresponding products cannot be exported to foreign countries, whichreduces user communities significantly and reduces our national economic income.After learning and analyzing the aforesaid information, this paper designs and makesseveral new types of compound materials for electromagnetic shielding, and alsocarries out corresponding tests and experiments on electromagnetic shieldingeffectiveness on the samples.Through detailed analysis on material characteristics of elastic polyurethane, thispaper takes polyurethane material as the base material for the compound materials ofelectromagnetic shielding. By magnetron sputtering coating technology, theresearchers prepare four different compound materials of electromagnetic shielding asNi-Cu-Ni, Ni-Al-Ni, Ni-Cu-Ti and Ni-Al-Ti through different permutation andcombination modes of the four metals as Ni, Cu, Al and Ti. They also elaborate thepreparation technology and processing methods before and after the processing. Thenexperimental analysis is conducted on electromagnetic shielding effectiveness of the4kinds of compound materials of electromagnetic shielding in both near and farfields. This paper lists the test methods for electromagnetic shielding effectiveness ofthe compound materials of electromagnetic shielding in detail. The electromagneticshielding effectiveness of the4prepared compound materials of electromagneticshielding is actually measured by means of “large sample method” and “waveguide coaxial changer” method. Good shielding effectiveness SE values are obtainedunder2-7GHz and7-15GHz respectively. By gradually analyzing electromagneticshielding conditions in both near and far fields, the paper concludes that under thecondition of near field, the shielding effectiveness of Ni-Al-Ni can reach a maximumof86dB; the shielding effectiveness value of Ni-Al-Ti is only5%lower comparedwith the shielding effectiveness values of other shielding materials. Under thecondition of far field, the shielding effectiveness of Ni-Cu-Ni can reach a maximumof95dB, while the shielding effectiveness values of Ni-Cu-Ti reduce by only11%.