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Cyclic Stress Measurement Method Using Grain Size and Occurrence Rate of Grown Grains in Electrodeposited Copper Foil
Author(s) -
Ono Y.,
Kitaoka S.
Publication year - 2011
Publication title -
strain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.477
H-Index - 47
eISSN - 1475-1305
pISSN - 0039-2103
DOI - 10.1111/j.1475-1305.2008.00482.x
Subject(s) - grain size , materials science , amplitude , nucleation , shearing (physics) , copper , grain growth , metallurgy , electroplating , weibull distribution , stress (linguistics) , foil method , composite material , mathematics , optics , thermodynamics , physics , linguistics , statistics , philosophy , layer (electronics)
The copper electroplating stress measurement method uses the grain growth in copper foil. The grain growth is a kind of thermal recrystallisation that is affected by the magnitude of pre‐straining. As a lot of grain nucleation occurs at the large pre‐straining, the large shearing stress should also lead to the same effect. On the basis of the above, we investigate the stress dependence of the grown grain size. We confirmed that the size of grown grains is expressed by using the three‐parameter Weibull distribution, and the relationship between scale parameter and arithmetic mean of grain size has a linear relationship until the grown grain density reaches 50%. It is also recognised that the mean grown grain size becomes smaller with increasing shearing stress amplitude. To measure the shearing stress amplitude, the relationship between mean grain size, shearing stress amplitude and the number of cycles is experimentally formulated. Moreover, even if the number of cycles is unknown, measuring both grown grain density and mean grain size enables us to estimate the shearing stress amplitude.