COPPER AND COPPER BASE ALLOY EXCELLENT IN WIRE BONDING PROPERTY AND DIE BONDING PROPERTY AND PRODUCTION THEREOF

摘要

PROBLEM TO BE SOLVED: To obtain good solderability in a die pat part without using flux by using an alloy in which crystal grain size lies in a specified range, and the center line average roughness (Ra) and the thickness of an oxidized film are controlled to the value equal to or below the specified one respectively. ;SOLUTION: By heat treatment, copper and copper base alloys having 10 to 150 μm crystal grain size, ≤0.15 μm center line average roughness (Ra) and ≤6 nm oxidized film thickness and excellent in wire bonding properties and die bonding properties are obtd. This copper and copper base alloys, which contain, by weight, 0.01 to 0.5% P or at least one kind from the group of Fe, Ni, Sn, Zn, Cr, Co, Si, Mg, Ti and Zr by 0.01 to 5.5% in total, and the balance Cu with inevitable impurities, are heat-treated at 300 to 900°C for 0.01 to 72 hr in an atmosphere of ≤5% oxygen concn. For stably joining a lead frame and a bonding wire, the surface roughness of the material is desirably controlled to 0.06 to 0.12 μm. By controlling the crystal grain size range to the above, solder uniformly spreads.;COPYRIGHT: (C)2000,JPO