| 摘要 |
PROBLEM TO BE SOLVED: To provide a lead-free high-temperature soldering material which is lead-free, capable of improving the thermal fatigue performance, friendly to the environment, and capable of improving the reliability of the electronic equipment by providing a soldering material which has the composition containing, by weight, 0.005-3.0% palladium(Pd) and 97.0-99.995% tin(Sn), and whose liquidus temperature is 200-350 deg.C. SOLUTION: Sn metal and Pd of the prescribed quantity are mixed, and melted in vacuum, and forged to obtain an ingot, the ingot is rolled to form a tape, and the tape is pressed to finish the solder pellet. The preferable composition consists of, by weight, >=95% Sn and 0.005-3.0% Pd, and the metallic or alloy grain such as Ni and Cu whose mean grain size is around 40μm is added by 0.1-5.0%. A substrate and a semi-conductor IC chip 5 which is a chip-shaped electronic element are connected (die-bond) to each other with the soldering material 3 in an approximately parallel manner through the Ni plating 4 of a lower side of the IC chip 5 and a Ni plating of a face side of a die 1. |
