Fabrication of micro-hole arrays using precision filled wax metal deposition

This study presents a low-cost hybrid fabrication process that produces micro-holes of less than 200 μm in diameter. First of all, a micro-EDM hole-drilling is employed to perforate micro-holes through the mirror-like substrate (SUS304), which is cylindrical in shape. The oily wax also known as "sacrificial material" is extruded and formed onto the SUS304 substrate, resulting in a precision cylindrical micro-wax pillar mould. A precision electroforming is then conducted to deposit a thick nickel metal layer onto the substrate, and subsequently the wax mould is completely removed and revealed a perforated micro-hole array after releasing from the substrate. Experimental results show that the wax mould has an excellent duplication capability. The finished micro-hole array has an average hole-diameter of 165.3 μm and demonstrates ideal geometric accuracy. The proposed approach can significantly cost down and contribute to the precision machining industry.