A Study of Integration of LIGA and M-EDM Technology on the Micro Injection Molding of Super Thin Plates with Micro Through Holes

Abstract

There are still some difficulties in injection molding a super thin plate with micro through holes. Nozzle or filter plates are some examples of typical products. Conventional processes to manufacture nozzle plates of ink jet printer heads are electroplating or laser machining. In order to reduce the production cost and improve the performance of nozzle plates, a new approach, micro injection molding, is introduced to manufacture nozzle plates in this study. The micro mold was made by integration of the LIGA and M-EDM technology to improve the positioning and alignment accuracy. After assembling the micro mold, micro injection molding technique was applied to produce four nozzle plates in one shot. There are sixty micro through-holes on each plate and their diameters have been inspected and met the specification, 101 ± 1 microns, under a proposed vario-thermal molding process. The flow hesitation problem for molding a thin film of 50 microns was then solved. Experimental and simulation results indicated that the most significant factor for molding these nozzle plates is the initial mold temperature. This work recommends that the best initial mold temperature for molding such a thin film with the nozzle array is about 150°C for PP. The manufacturing procedures proposed here are believed to be more accurate and economical, and can be applied to mold similar micro parts.