Selective Anodization Process Research Articles

알루미늄 양극산화를 사용한 LED COB 패키지

알루미늄 기판 및 양극산화 공정을 사용하여 LED Chip on Board(COB) 패키지를 제작하였다. 선택적 양극산화 공정을 적용하여 알루미늄 기판 상에 알루미나를 형성하고 이를 COB 패키지 절연층으로 사용하였으며, 비아홀 내부가 충진된 구조의 Thermal Via를 구현하였다. 패키지 기판 종류에 따른 열저항 및 발광효율 변화를 파악하기 위해 알루미늄 기판과 알루미나 기판을 제작하고 이를 각각 비교 분석하였다. Thermal Via가 적용된 알루미늄 기판이 51%의 열저항 개선 및 14%의 발광효율 향상 특성을 보여주었다. 이러한 결과는 선택적 양극산화 공정 및 Thermal Via 구조적용으로 COB 패키지의 방열 특성이 향상되었음을 의미한다. 또한 동일한 전력 소모시 LED 칩 개수에 따른 COB 패키지의 열저항 및 발광효율 변화를 분석함으로써 다수 칩의 효율적인 배치가 열저항 및 발광효율을 증가시킬 수 있음을 확인하였다. LED chip on board(COB) package has been fabricated using aluminum substrate and aluminum anodization process. An alumina layer, used as a dielectric in COB substrate, is produced on aluminum substrate by selective anodization process. Also, selective anodization process makes it possible to construct a thermal via with a fully-filled via hole. Two types of the COB package are fabricated in order to analyze the effects of their substrate types on thermal resistivity and luminous efficiency. The aluminum substrate with the thermal via shows more improved measurement results compared with the alumina substrate. These results demonstrate that selective anodization process and thermal via can increase heat dissipation of COB package in this work. In addition, it is proved experimentally that these parameters also can be enhanced using efficient layout of multiple chip in the COB package.

Selective anodization using masked deep ion implantation

This paper describes the initial experiments aimed at determining the effectiveness of masked, deep ion implantation for improving the dimensional control and the packing density of features etched in silicon using the selective anodization process. It also shows how this process can be utilized to obtain variations in shape of an etched feature in the depth direction, hence enabling a true 3D microengineering technique.

Anodized niobium as barrier for Josephson tunnel junctions

We have fabricated Nb-NbOx-Pb Josephson tunnel junctions in which the barrier is formed by anodization of the niobium electrode. The anodized barrier is made thick (>100 Å) to then be sputter etched to the desired thickness. The geometry of the niobium electrode is defined by a selective anodization process and the lead electrode is patterned by chemical etching. The I-V characteristics of 10−6-cm2 rectangular junctions have been measured at 4 K. Our junctions exhibit large leakage current and low ICRN product, making them less attractive for practical applications than junctions made by other techniques. However, the ease of fabrication and reasonable reproducibility of the electrical characteristics of our junctions make our method of fabrication quite useful when high quality of the barrier is not a stringent requirement. Noise measurements in our junctions and electron diffraction analysis of niobium-oxide films grown by anodization confirm the presence of a large number of defects in the barrier.