Fabrication of the 7$\times$7 mm Planar Inductor for 1W DC-DC Converter

1W DC-DC 컨버터를 위한 7$\times$7 mm 평면 인덕터의 제조

The planar type inductors have a good potential for the application of miniaturized low power DC-DC converters. For those high quality application, the reduction of coil loss and also magnetic films which have good high frequency properties are required. Fabricated inductor was consisted of FeTaN/Ti magnetic film and electroplated Cu coil thickness of 100$\mu\textrm{m}$ and $SiO_2$ as a insulating layer. The inductor was designed double rectangular spiral shape for magnetic field highly confining within the device. The measured value of inductance and resistance were 980 nH and 1.7 $\Omega$ at 1 MHz as operating frequency of device. The Q factor is 3.55 at 1 MHz.

1W급의 DC-DC converter에 탑재하기 위해 FeTaN 연자성 자성박막을 이용한 박막형 인덕터를 제조하여 특성을 평가하였다. 자심부분은 2$\mu\textrm{m}$ 두게의 F $e_{78.81}$T $a_{8.47}$ $N_{12.71}$ 연자성 박막을 사용하였으며 코일부분은 100$\mu\textrm{m}$ 두게의 Cu를 사진공정과 전기도금공정을 이용하여 제조하였다. 제조된 박막 인덕터의 디자인은 상호인덕턴스를 효율적으로 증가시킬 수 있는 double rectangular spiral형태였으며 측정된 특성은 DC-DC converter의 작동주파수인 1 MHz에서 인덕턴스 980nH, 저항 1.7 $\Omega$Q 값은 3.55였다.다.