Method for measuring metallic film fatigue life on a flexible substrate

Abstract

The invention discloses a fatigue life test method of metallic film on a flexible substrate, which comprises processing fatigue test under integral circulation stress load on a metallic film / flexible substrate system with better interface combination, recording the stress-strain curvature and resistance change-circulation frequency curvature of the metallic film, detecting the metallic film microcosmic structure under different circulation frequencies in the fatigue process to obtain a metallic film surface damage topography-resistance change-circulation frequency curvature. The invention uses the sharp increase of resistance change on the resistance change-circulation frequency curvature to represent metallic film damage and define a fatigue life Nf. The strain amplitude delta epsilon and relative fatigue life Nf obtained from the stress-strain curvature forms the metallic film fatigue property failure evaluation of the metallic film / flexible substrate system. The inventive method has simple test, accurate measurement and prior property.

Description

Test method for fatigue life of metal thin films on flexible substrates technical field The invention relates to a metal thin film material, which belongs to the field of thin film materials, and relates to the evaluation of the fatigue performance of the metal thin film material, in particular to a method for testing the fatigue life of the metal thin film on a flexible substrate. Background technique Flexible circuit boards are widely used in VLSI and microelectromechanical systems (MEMS). Usually, metal thin film materials (such as copper and aluminum) used as metallized wiring are deposited on the flexible substrate to form a metal thin film / flexible substrate. system. As a metal structure thin film material for engineering, its fatigue performance is an extremely important indicator, which can be used for material safety design and life prediction. However, because the metal thin film material is in the micron or submicron scale in the one-dimensional direction, the ...

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Problems solved by technology

For a long time, great attention has been paid to this problem at home and abroad, but there have been no reports about the specific determination method