| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a diagnosis method for simply and high-precisely estimating thermal fatigue life based on numerical analysis without reliability assessment of a real machine. <P>SOLUTION: The diagnosis method comprises the steps of: forming a solder bulk specimen; obtaining fatigue life data corresponding to a plurality of strains in a strain range assumed with the specimen; obtaining crack developing speeds corresponding to respective strains from the fatigue life data; forming a thermal fatigue life curve converted into the crack length of the solder joint part using the crack developing speeds; and estimating a thermal fatigue life corresponding to the strain of the solder joint part obtained by the numerical analysis using the thermal fatigue life curve. <P>COPYRIGHT: (C)2012,JPO&INPIT |
