Flip Chip Solder Ball Rework Process
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
The flip-chip solder ball contact structure shown in Fig. 1 has been described, for example, in U.S. Patent 3,401,055. As shown in Fig. 1, the aluminum conductor line 2 on the surface of the semiconductor substrate 1 is exposed through a via hole in the polyimide layer 3, so that a sequence of the chromium layer 4, the copper layer 5, and the gold layer 6 may be deposited thereon, forming the ball limiting metallurgy (BLM) contact. A molybdenum mask 7 having a hole 8 therein is juxtaposed over the ball limiting metallurgy, and the assembly is inserted in a vacuum evaporator.