| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for examining using X-rays a soldered state formed by ball solder, capable of precisely determining, based on fluoroscopic images, the state of the soldered joints of a BGA(ball grid array) or CSP(chip scale package) on a packaging substrate or the state of in-chip joints such as gold bumps. SOLUTION: The isosbestic cross-sectional shape of a fluoroscopic image produced by application of an X-ray to the soldered part of ball solder in a normally joined state is determined in advance to serve as a reference. Next, the isosbestic cross-sectional shape of a fluoroscopic image of the soldered part of the ball solder after junction is depicted by application of an X-ray to a specimen for examination, and the depicted isosbestic cross-sectional shape of the specimen for examination is compared with the reference isosbestic cross-sectional shape, to determine whether or not the soldered state of the ball solder is permissible from differences in changes of the isosbestic cross-sectional shape.</p> |
