The linkage-spring model based on a quasi-static looping has been used to determine the design rules to reduce the loop heights and the sagging altitude of gold wire in the package. In order to further simulating the capillary trajectory which includes a looping speed factor from the first bond to the second bond stages, a linkage-spring model is modified in this study. The factors of the inertia mass and variations in material properties with different strain-rates need to be considered due to a high speed looping. It is found that the looping speed effects on the wirebond profiles due to the inertia mass can be neglected at a regular looping process of 3-5g acceleration even up to around 10g acceleration. However, variations in the material properties during deformation at different strain-rates could be an important factor on the wirebond profiles. Fortunately, a pure annealed state like pure gold wire would be little strain-rate sensitivity. The effects of the strain-rate in pure gold wire, therefore, can be excluded in analysis. Accordingly, a linkage-spring model based on the quasi-static looping is still applicable in analyzing the wirebond profiles.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Safety, Risk, Reliability and Quality
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering