Formation of bump

Abstract

Abstract PURPOSE:To reduce the cost of a bump electrode for a flip-chip by forming the bump electrode by wire junction method. CONSTITUTION:A tip of a wire 5 protruded from the bottom end of a capillary 1 is heated by a torch 4 to form a ball 5a and the ball is joined firmly by heat on a pad 3. The wire 5 is tore off above the ball 5a by the movement of a clamper and a bump electrode 6 is left. With this process, a satisfactory bump electrode 6 is formed easily and with low cost by utilizing nail-head junction. The wire 5 is made of Al, Cu, Au, solder and the like. If the ultrasonic method is applied for the junction, the similar satisfactory results can be obtained and a low cost bump electrode can be formed easily.

Inventors

• 👤 Ken Okuya
• 👤 謙 奥谷

Bibliographic Details