2022 年 22 巻 2 号 p. 120-123
Directly measuring mechanical properties of freestanding films, such as electroplated films, is required for reliable mechanical design of devices. However, due to its technical difficulties, mechanical testing of thin films has been rarely conducted. In this paper, a high-throughput uniaxial tensile test technique and its technical issues for freestanding thin films are described. The combination of a lift-off-processed freestanding film and a micromachined Si frame enables us to carry out uniaxial tensile testing of a film material. An electroplated metallic film glued onto a Si substrate having a spring system is stretched in the axial direction. During the test, the distance between two gauge marks in the specimen’s parallel section is directly measured using a CCD image analysis system for tensile elongation measurement. The applied force is measured using a load cell. Uncertainty of force-displacement relationship is discussed from the aspect of an error related to specimen preparation and the image analysis system.
