2010 Fiscal Year Final Research Report

Digital monitoring for prognostics to defects due to atomic migration

Research Project

Project/Area Number	21760068
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Materials/Mechanics of materials
Research Institution	Yokohama National University
Principal Investigator	SHIBUTANI Tadahiro Yokohama National University, 環境情報研究院, 准教授 (10332644)
Project Period (FY)	2009 – 2010
Keywords	原子輸送 / 微小欠陥 / 応力 / 破壊予知 / モニタリング
Research Abstract	The aim of this project is to establish a methodology of in-situ observation for phenomena of small defects due to atomic transportation. Key technology is to predict the site of defects under some environmental conditions. In this study, pressure-induced tin whisker test was conducted for silver doped tin surface finish. Since doped silver can mitigates tin whiskers, it is not suitable for monitoring of tin whisker. On the other hand, long whiskers were observed under corroded samples with electric currents. The driving force of tin whiskers, stress gradient in the surface finish, was generated by surface oxides and distorted electric currents. Based on the above mechanism of tin whiskers, In-situ observation system for tin whiskers were proposed by using micro-manipurator and atomic force microscopy.

(4 results)