| 摘要 |
PROBLEM TO BE SOLVED: To provide a solder ball that has solved both of the problems of micro-adhesion and wetting properties, and to provide a method for preventing the micro-adhesion of solder balls. SOLUTION: The prevent invention provides the solder ball obtained by solidification and spheroidization in a gas phase and adsorbed with metal soap molecules, preferably a metal soap molecules of 3 nm or less in thickness, on its surface. As the metal soap, e.g., calcium stearate, magnesium stearate or barium stearate can be used. The present invention is preferably applied to solder balls with a diameter of 400μm or less. The present invention also provides a method for preventing the micro-adhesion of solder balls, which comprises immersing solder balls obtained by solidification and spheroidization in a gas phase, in a solution containing a metal soap dispersed therein to a concentration of less than 5 ppm; taking out the solder balls from the solution; vaporizing the solvent on the surfaces of the solder balls; and then drying the surfaces. The drying is preferably conducted in an atmosphere having a relative humidity of RH≤40%, more preferably of RH≤20%. COPYRIGHT: (C)2006,JPO&NCIPI
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