Electroplated stencil reinforced with arch structures for printing fine and long conductive paste

Abstract

This study presents an MEMS-based stencil reinforced with arch structures and a surrounding buffer reservoir for printing conductive paste of fine and long lines. The developed reinforced stencil successfully solves the problems came with the conventional stencil structure including limited printable line width and ease of fracture. A novel process was developed to fabricate a thin yet robust electroplated stencil by using two AZ4620 layers and one SU-8 layer as the electroplating molds. A precise stencil with a long and high-density line structure can be produced with the developed method. The printing results show that the developed stencil is capable of printing parallel lines of 20 µm in pitch. The printable length of the fine parallel lines is longer than 10 mm with the arch structure reinforced stencil. In addition, the developed stencil is capable of printing closed ring patterns with small pitch, which is not possible to be printed using conventional stencil or screen printing technologies. The MEMS-based stencil developed in the present study will give substantial impact on the paste printing technologies.