| 摘要 |
PURPOSE:To obtain a highly reliable lead frame with low cost by forming a copper layer with purity of 99.999% or more in a wire bonding region at the tip of an inner lead by sputtering method or vapor-deposition method, and performing bonding after chip mounting by using the similar copper wire of high purity. CONSTITUTION:Belt-type material composed of copper is worked upon a lead frame 1 by stamping method; by coining process, flat width of the tip of an inner lead 4 is secured; then a copper layer 10 with purity of 99.999% or more is formed in the bonding area of a die pad 2 and the tip of each inner leads 4 by sputtering method or the like. A semiconductor chip 3 is fixed on the die pad 2; the bonding area of the tip of each inner lead 4 and the bonding area of the chip 3 are connected by using the similar copper wire 5 of high purity; after that, resin sealing is performed; while the tips of outer leads 8 are exposed, a lead frame constituting body is sealed; a tie bar 7 is cut and eliminated; the tips of the leads 8 are bent in the desired direction. |
