Micro deep drawing of T2 copper foil using proportional decreased tools

Abstract

Cooper foils are widely used in micro electronic industry, and they are suitable to be deep drawn to form cup-like parts. In this study, micro deep drawing experiments were conducted by using T2 copper foils after an annealing process, and three scale factors (λ = 0.5, 1, and 2) were set to indicate effects of proportional decreased tool dimensions and processing parameters on the forming result. The experimental results show that micro deep drawing parts with internal diameters of 0.5, 1.0, and 2.0 mm can be formed successfully. And the 0.5-mm cup drawing part has achieved the minimum dimension in recent reports. The standardized punch travel-deep drawing force curves are similar, and the maximum deep drawing force is decreased with smaller scale factor. The thickness distributions of different processing parameters are all decreased firstly and then show the trend to increase from bottom to upper regions. We find that the size effect influences the maximum deep drawing force during the forming process and the quality of forming part. And the maximum limit drawing ratio (LDR) is 2.2 for the experiment with scale factor of 0.5. Forming regularities of the proportional decreased micro deep drawing process can be presented clearly by changing the scale factor.