Method for diagnosing the life of a solder connection
US5291419A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 6, 1992 |
| Grant date | Mar 1, 1994 |
| Priority date | — |
| Expiry date | Jan 6, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2203/0296
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for evaluating the life of a connection between members including the steps of extracting parameters defining the shearing strain of a predetermined model representing the connection thereby to calculate the values of plural shearing strains of the connection, calculating the equivalent strain amplitude corresponding to thermal fatigue stress for each of the values of the plural shearing strains defining the relationship between the shearing strain and the equivalent strain amplitude, formulating a life evaluation criterion equation expressed using the equivalent strain amplitude, calculating, for the connection, the equivalent strain amplitude corresponding to each of the shearing strains actually measured using the equation, and substituting the equivalent strain amplitude for the life evaluation criterion equation to acquire the life of the connection. Further, in this method, an equation for evaluating the advancement of a crack is made using the equivalent strain amplitude, and the equivalent is substituted for the crack advancement evaluation equation to calculate the length of the crack.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.