Furukawa Electric Review No.51Influence of the Crystal Orientation and the Grain Size on the Flexing Property of Tough Pitch Copper

Ryosuke Matsuo

We researched the influence of the crystal orientation and the grain size on the flexing property of tough pitch copper (C1100). As a result of the Institute of Interconnecting and Packaging Electronic Circuits (IPC) bending tests under the same conditions, a sample oriented to a {001}<100> orientation (W-orientation) had a better life than a sample oriented to a {001}<110> orientation (NDW-orientation). As a result of a surface observation and an analysis after the tests, the surface of the sample oriented to a {001}<110> orientation (NDWorientation) was confirmed to have a surface roughness and some cracks which was assumed to be the starting point of fracture, which is contrary to the sample oriented to a {001}<100> (W-orientation). In addition, in the case of a random orientation, it was clarified that the smaller the crystal grain size, the better the bending performance. In addition, in the case of a random orientation, it was clarified that the smaller the crystal grain size, the better the flexing property.