摘要 |
A novel method for fabricating leadless solder for IC packaging includes the following steps: A. to prepare a mixture containing Zn, 7-11 wt %; Co, 0.1-0.5 wt %; and Sn for balance; or a mixture containing Zn, 7-11 wt %; Co, 0.1-0.5 wt %; P, 0.005-0.05 wt % and Sn for balance; or a mixture containing Zn, 7-11 wt %; Al, 0.1-0.5 wt %; and Sn for balance; a mixture containing Zn, 7-11 wt %; Al, 0.1-0.5 wt %; P, 0.005-0.05 wt % and Sn for balance; or a mixture containing In, 10-15 wt %; Co, 0.1-0.5 wt % and Sn for balance; B. to place the mixture in a high frequency furnace to be melted together at a temperature lower than 350° C., then take it out of the furnace for a quick freezing and cast it into an ingot in an adequate size; C. to treat the ingot with a homogenization processing at 180-240° C. for 30-240 minutes; D. to draw the homogenized ingot into the form of leadless solder filament or granule.
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