| 摘要 |
This invention provides screen printing for forming a higher solder ball (bump). In first printing step, a first solder layer is printed. After drying in drying step, a second solder layer is printed on the first solder layer in second printing step. Then, in re-flow processing step, re-flow processing is performed, and the first solder layer and the second solder layer are melted. Finally, the melted layer is solidified in a ball shape to form the solder ball (bump). Since solder paste is printed in layers, an amount of the solder paste can be increased. Hence, a higher solder ball (bump) can be formed. |
