电磁屏蔽箔



NanoMet

NanoMet项目开发了一种屏蔽箔,用于特定频率的电磁波,以保护数据载体。该屏蔽箔可以进一步加工成用以保护RFID银行卡,信用卡或芯片卡的保护盖。它可以防止未经授权的读取以及由于电磁影响造成的卡损坏。

 

所开发的箔是由载体膜(基底)组成的箔复合物,其上导电铜网嵌入CSP-聚合物复合物(CSP-芯钉颗粒)中。所使用的铜栅格显示出与隐秘相当的频率屏蔽。

 

屏蔽箔足够透明,因此满足读取插入卡的字体和识别其颜色的要求。此外,聚合物箔的柔韧性大于卡的柔韧性,类似于许可证持有者,膜厚度小于0.2mm。该箔片还具有良好的滑爽性,因此它不会粘在传统的卡片上。

 

箔可以以不同方式进一步加工。例如,它可以超声波焊接,同时保留功能性,并且具有轮廓和压碎可切割和可打孔的特点。与市场上的产品相比,箔具有相同或更低的毒性和颗粒排放。

如果使用自粘性载体箔,则会产生其他应用。

该箔可以以卷对卷工艺生产,这允许大批量生产。使用这种方法,可以在连续过程中生产更大的面积。

 

在该箔的开发过程中,测试了不同的表面活化方法,以优化基材和CSP聚合物复合材料之间的粘合性。 因此,载体箔在涂覆之前通过紫外照射进行热处理或用等离子体处理。 从而,等离子体处理改善了连接/粘附。
 
对于箔的连续生产过程,我们使用卷对卷工艺进行演示。 等离子体处理由机器上专门设计的工作站实施(图e)。


在此之后,将CSPC材料施加到载体箔上。 为此,开发了一种自动双筒系统,可以准确计量CSPC组件(c和d)。 在该系统的帮助下,可以调节两种聚合物组分的比例以及要施加的材料的量。 然后将铜网格与液体CSPC涂层结合在一起,接着用辊子制作成薄层。

演示:a)前视图; b)侧视图; c)和d)自动双筒系统作为配料单元; e)等离子体单元; f)成品箔复合材料的缠绕
演示:a)前视图; b)侧视图; c)和d)自动双筒系统作为配料单元; e)等离子体单元; f)成品箔复合材料的缠绕

 

 

该项目的另一个目标是开发阻燃薄膜,有机硅被证明是合适的材料。 通过添加CSP,可以增强该性能,如下图所示:随着添加剂含量的增加(从左到右),燃烧距离减小。

在最大层厚度为1毫米时,薄膜也具有足够的柔韧性,可切割性,并且可以在卷对卷工艺中生产。

Comparison of silicone samples, filled with different amount of CSP, after the burning test
Comparison of silicone samples, filled with different amount of CSP, after the burning test

The project was implemented in cooperation with the project partners:

 

Max Steier GmbH & Co.KG has extensive know-how in the use of foil materials. This company made the selection of suitable carrier foils and provided them. In addition, they performed tests according to further processing of the developed shielding foil for making card-cases and other functional specimens.


Teyfel Automation designed the machine technology which enables a roll-to-roll application. As a machine frame, an old apparatus of the company Steier was used and modified. An automated two-cartridge system as a dosing device enables the application of a viscous medium, in which the microstructures are dispersed, on a carrier foil pretreated with plasma. With the help of an additionally installed rolling device with adjustable contact pressure, viscous media can be distributed to thin films of defined layer thickness.


In the working group 'Functional Nanomaterials' of the Christian-Albrechts-University to Kiel, the basics of ZnO microparticle production were determined. In addition, the mechanical and electrical characterization of the novel foil was carried out.


The Plasma Technology AG of the CAU has many years of experience in the field of surface modification and coating by means of low-temperature plasma processes. Thus, suitable plasma processes could be selected for this specifically application. The plasma is needed to activate the substrate material to ensure better adhesion of the overall composite. As the utilized substrates consist of temperature-sensitive plastics, the temperature load of the substrate was examined and different process parameters were adjusted, such as power, working distance or travel speed of the plasma source.