Precision micro-punching process of T2 copper foil

With the development of micro-electro-mechanical system (MEMS), the micro-holes are widely used in the fields of biomedical medical treatment, micro-electronic, textile dyeing devices with high precision, good quality of sheared edge and dimension stability, which can satisfy the industrial demands of low cost and mass production. Micro-punching has advantages of the traditional plastic forming technique in high mass production, simple processing, fine property and high dimensional precision, which is very suitable for mass production of micro-parts. The micro-punching dies were designed and the punching processes of micro-holes were studied in different blanking conditions. The results show that the process of micro-punching is similar to the conventional punching and the process of micro-punching is composed of elastic deformation stage, plastic shearing stage, fracture and separation stage. Moreover, the sheared edge is still composed of rollover zone, shearing zone, fracture zone and bur. In the punching process, the maximum shearing strength firstly decreases and then increases with the increase of the relative blanking clearance. The maximum blanking force and shearing strength decrease with the increase of the blanking velocity. Moreover, the depth of the shearing zone increases and the quality of cross section is improved. In the end, the micro-hole of 0.4 mm in diameter was manufactured with good quality in the optimum blanking condition of relative blanking clearance of 5% and blanking velocity of 20 mm/s.