A kind of wave-absorbing multilayer film and its preparation method

Abstract

The invention relates to the field of magnetic material preparation, in particular to a wave-absorbing multilayer film and a preparation method thereof. The wave-absorbing multilayer film is a multilayer film prepared on a substrate, and is divided into three parts from bottom to top, which are substrate, middle layer and top layer in sequence. The middle layer is composed of n units stacked sequentially from bottom to top, n≥1, the unit is a double-layer unit structure in which the lower layer has a magnetic layer with a resonant absorption frequency of f1 and the upper layer is an isolation layer, and finally stacked in sequence as f1‑fn The middle layer of 2n layers. The top layer is composed of uniformly arranged strip-shaped FeCo-based alloy magnetic films, and the number of strip-shaped films is ≥2. The resonant absorption frequencies of the magnetic layers of f1‑fn are the same and / or different. The invention effectively broadens the absorption frequency band of the wave-absorbing multilayer film, and is not limited to the absorption frequency of the material itself, and effectively widens the absorption frequency band of the material to high frequency, and can be used in devices such as noise suppressors and transmission lines.

Description

technical field [0001] The invention relates to the field of magnetic material preparation, in particular to a wave-absorbing multilayer film and a preparation method thereof, which can be used in devices such as noise suppressors and transmission lines. Background technique [0002] With the development of radio communication technology and the high integration of electronic equipment, the high-density and wide-spectrum electromagnetic signals generated by integrated electronic devices in operation fill the entire space, forming a complex electromagnetic environment, which requires electronic equipment and power supplies to be in each All frequency bands have good electromagnetic compatibility, which brings a series of challenges to the anti-electromagnetic interference technology. [0003] High-frequency magnetic film has excellent electromagnetic loss effect at high frequency, and its thin and light characteristics make it have good application prospects in highly integra...

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Problems solved by technology

In order to realize the absorption of electromagnetic waves in a wider frequency band, there are two ideas in theory: one is a single-layer magnetic film, which broadens the resonance absorption frequency band of the film by increasing the damping factor of the film magnetic moment resonance, but simply controls The damping factor is difficult, and excessive damping will also reduce the absorption effect of the film; another way of thinking is a multilayer film, in [Zhang L, Zheng H, ZhuW, Li M, Zhang M, Wang N, Lu H P, Xie J L, Deng L J(2016), J.Alloys Compd, vol.657, pp.174-178] discloses a multilayer film combining FeCoB and FeCoSiB, the resonant absorption frequency of the film is the resonant absorption frequency of FeCoB (3~ 3.25GHz) and the resonance absorption frequency of FeCoSiB (1.96-2.13GHz), but this method can only combine the absorption frequency of the magnetic film itself, and it is difficult to further broaden the resonance absorption frequency to high frequencies

The resonance absorption frequency of FeCo-based thin films is higher than that of most magnetic thin films. If you want to further broaden the resonance absorption frequency to high frequencies, you need to find magnetic materials with higher absorption frequencies, but this is very difficult in itself. of

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