Burr formation during micro via-hole punching process of ceramic and PET double layer sheet

Nowadays, recent electronic equipments are becoming smaller, multi-functional, and more complex. Similarly, low temperature co-fired ceramic (LTCC) has been emerged as a promising technology in the packaging industry. It consists of a multi-layer ceramic sheet, and a three-dimensional circuit. The via hole formation in LTCC plays an important role in providing an electric path for the interconnection between circuits. Therefore, via hole quality has a very important role for ensuring the performance of LTCC product. Via holes are formed on the green sheet that consists of ceramic (before sintering) layer and PET (Polyethylene terephthalate) layer. In this paper, we will discuss about the correlation between hole quality and process condition such as ceramic thickness, tool size, etc. The shear behavior of double layer sheet by micro hole punching which is different from that of single layer one will also be discussed.