| 摘要 |
PROBLEM TO BE SOLVED: To provide cream solder which has excellent strength of adhesion and electrical characteristics and does not give rise to a tombstone phenomenon. SOLUTION: The cream solder is prepared by kneading 80 to 95 wt.% mixture composed of 2 to 10 pts.wt. alloy powder of 81 to 92% Sn-5 to 10% Sb-3 to 9% Cu, 15 to 25 pts.wt. alloy powder of 60 to 65 to 64% Sn-1 to 3% Ag-33 to 39% Pb and 65 to 83 pts.wt. alloy powder of 60 to 65% Sn-35 to 40% Pb or 90 pts.wt. and 5 to 20 pts.wt. flux for cream solder. Otherwise the cream solder is prepared by kneading 90 wt.% powder mixture formed by mixing a) respective alloy powders of Sn-Sb, Sn-Ag-Pb and Sn-Pb, b) respective alloy powders of Sn-Ag, Sn-Cu and Sn-Bi, c) respective alloy powders of Sn-Zn, Zn-Al and Sn-Cu, d) respective alloy powders of Sn-Zn, Zn-Al and Sn-Cu and e) respective three kinds of the Sn powder, the Sn-Ag alloy powder and Sn-Cu alloy powder and 10 pts.wt. the flux for cream solder. The adhesion method using the same is provided.
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