| 摘要 |
[Problem] To improve the ultrasonic joining properties, electrical conduction capacity and loop characteristics of a bonding ribbon that is to be used in the connection between a semiconductor element pad and a lead on a substrate side. [Solution] A ribbon composed of a copper core and an aluminum coating layer, wherein the copper core consists of a copper having a Vickers hardness of 70Hv or less and a purity of 99.9 mass% or more and thus imparts electric conductivity and loop formation properties, while the aluminum coating layer is formed by depositing aluminum having a purity of 99.9 mass% or more in an inert atmosphere of argon gas, helium gas or the like and thus has a dense fine crystal structure having a Vickers hardness of 30Hv or more. Therefore, the ribbon has a reduced hardness difference between the core and the coating layer, rarely damages an aluminum pad, and exhibits improved joining properties. The aluminum fine crystal structure deposited in an inert atmosphere has a higher hardness than that of an aluminum bulk, so that the ribbon suffers from neither breaking nor peeling even when looped. |
