RFID抗干扰镀层制备及其抗干扰性能影响

Preparation of RFID Anti-interference Coating and Its Effects on Anti-interference

目的为了将RFID技术应用到仿金属类包装领域,研究一种RFID抗干扰金属镀层制备技术,同时研究抗干扰镀层厚度对RFID标签可识别读取距离的影响。方法利用铟锡合金(铟锡质量比1:9和2:8)或纯铟(铟含量99.9%以上)等金属特性,采用在塑料表面进行前处理、喷涂UV底漆、真空蒸发镀膜、喷涂UV面漆等加工工艺,得到一种厚度约为200~300 nm的RFID抗干扰金属镀膜层。采用扫描电镜和真空蒸发镀膜原理,分析了RFID抗干扰金属镀层呈岛状模式的生成过程。将RFID标签紧密粘贴在抗干扰金属镀膜层表面,分别采用Voyantic RFID标签测试系统和手持式RFID读写器,测试了RFID标签在不同抗干扰合金镀层表面的可探测识别距离。结果采用上述方法制成的RFID抗干扰金属镀层,贴上芯片频率为920~925 MHz的RFID标签,利用专用RFID读写器读取,均能够正常识别读取。利用Voyantic RFID标签测试系统得到RFID标签可探测读取距离在68.0~83.0 cm之间,利用手持式RFID读写器得到RFID标签可探测读取距离在28.0~33.2 cm之间。同时研究得出,镀膜层厚度对RFID标签可识别读取距离有一定影响,随着镀膜次数的增加,合金金属镀膜层厚度随之增加,而RFID标签可识别读取距离逐渐减小。对于部分合金,当合金金属镀膜层厚度达到一定值时,RFID标签可识别读取距离接近零。结论有效解决了RFID技术的金属干扰问题,达到了RFID技术在仿金属包装领域能够正常使用的目的。

The work aims to apply RFID technology to the field of metal-alike packaging area, study a preparation technology of RFID interference-free metal coating, and investigate effects of thickness of anti-interference coating on identifiable reading distance of RFID tags. By taking advantage of such metal features as indium-tin alloy （indium-tin mass ratio of 1：9 and 2：8） or pure indium （over 99.9% indium content）, a nearly 200~300 nm thick RFID anti-interference metal coating was obtained by adopting such processing technologies as pre-treating plastic surfaces, spraying UV undercoats, vacuum vapor coatings, and spraying UV finishing coats. Formation process of RFID anti-interference coating in island mode was analyzed by adopting scanning electron microscope and vacuum vapor coating principle. RFID tag was closely pasted on the surface of anti-interference metal coating, and detectable identification distance of RFID tag on different anti-interference alloy coating surfaces was tested with Voyantic RFID tag test system and handheld RFID reader, respectively. Special RFID reader could identify and read the RFID anti-interference metal coating as-prepared in aforementioned method pasted with RFID tag with chip frequency of 920~925 MHz. Detectable reading distance of the RFID tag as measured with the Voyantic RFID tag test system was 68.0~83.0 cm, and that as measured with the handheld RFID reader was 28.0~33.2 cm. Coating thickness had certain effects on detectable reading distance. As plating times increased, thickness of alloying metal coating increased while the detectable reading distance of RFID tag decreased gradually. For some alloys, the detectable reading distance of RFID tag was nearly zero when the thickness of alloying metal reached certain level. The work effectively solves the problem of RFID technique＇s metal interference, which allows RFID technique to function normally in the field of metal-alike packaging.