Development of planar devices using low-loss materials

低電力損失の平面デバイスの開発

伊藤 直樹*; 間瀬 淳*; 近木 祐一郎*; 瀬古 典明; 玉田 正男; 坂田 栄二*

Ito, Naoki*; Mase, Atsushi*; Kogi, Yuichiro*; Seko, Noriaki; Tamada, Masao; Sakata, Eiji*

ミリ波車載レーダやマイクロ波・ミリ波イメージングシステムの高性能化には、効率の良い小型平面デバイスの開発が不可欠であり、アンテナ基板として、低損失材料としてフッ素樹脂(PTFE)材料の使用を図ってきた。しかし、フッ素基板と導体パターンの付着力が低いことと基板上に形成可能な導体回路パターンの形状に関する問題があった。そこで、PTFEの表面に放射線グラフト処理を行うことで、低損失高周波デバイスの実現を図った。その結果、PTFEと銅箔の剥離強度を約4倍改善できた。

As the importance of advanced microwave and millimeter-wave diagnostics increases, the fabrications of high-performance planar devices become essential. This paper describes the development of planar devices such as antennas using low-loss fluorine materials. The problems to be solved for the present purpose are the low degree of adhesion between copper foil and fluorine substrate and the accuracy of device pattern using conventional fabrication techniques. In order to solve these problems, surface treatment of fluorine films and a fabrication method using Electro-Fine-Forming (EF2) are proposed. The peel adhesion strength between the metal and the fluorine films and the value of dielectric constant of the fluorine films before and after grafting are reported. In order to confirm the performance of the treated films, microstrip lines are fabricated on the conventional fluorine substrates and on the grafted-PTFE (Polytetrafluoroethylene) films. The prototype antennas using fluorine substrates with EF2 fabrication technique are also introduced.