Micro Stretch Forming of Foil using Lithography Process

点击翻译按钮获取中文摘要

The punch stretchability lowers even in the material which has good formability like aluminum, when the sheet thickness extremely decreases like the foil. This study aims for such material with small thickness to give a method for forming dome shape. The principle of the forming process is not tension in plane but compression for the thickness direction. The process is as follows ; first, the sheet is wrinkled, and the second the corrugated sheet is extended like a lantern. This study started from to produce the corrugated sheet by mechanical means. The tooth-profile tool was made by cylinder pin of 0.5 mm diameter, and the tool compressed the aluminum foil of 20 μm thickness against a flat die. As a result, the flat foil wrinkled and became the corrugated sheet. This corrugated sheet received tensile test, and large elongation was obtained. Next, the method for producing the corrugated sheet by the lithography processing was examined. The resist was applied by the spinner, and dried by the oven. Then, it was exposed by the Hg-Xe lamp, and the treatment of the development and the etching were carried out. The mask of the stripe pattern was made for oneself. The surface of the aluminum foil after the lithography processing was examined and it was found that the grooves were made regularly. This processing was applied for the both sides of aluminum foil. The limit tensile strain of the processed sheet was measured. As the result, it was found that only small strain was obtained against our expectation. So, it was clarified that the mechanism of the rupture had to be analyzed first of all.