| 摘要 |
PROBLEM TO BE SOLVED: To form a metal bump on a metal pad without a defect, by anisotropically etching a metal ball forming member made of an Si wafer to thereby form a recessed part, and transferring a metal ball formed by heating a solder paste filled in the recessed part onto an electrode pad. SOLUTION: A metal ball forming member 10 made of an Si wafer whose wafer face is inclined from a (110) face by 10 deg. in the <001>, direction and is expressed by (981 981 100) is anisotropically etched. A recessed part 11 in which the deepest partαis reduced to 63.7% as compared with that of the (110) face is formed at a 150μm pitch. A metal ball 2 formed by heating a soldering paste 1 filled in the recessed part 11 is transferred to an electrode pad 51 of an electronic part 50, thereby forming a metal bump 3. Consequently, positional variation of the metal balls 2 is eliminated. Thus, certainty when the metal ball 2 is transferred to the electrode pad 51 to form the metal bump 3 is promoted. |
