Design And Optimized Manufacture Of Micro Actuator Membranes For Inkjet Piezoelectric Printhead

Inkjet printing devices,taking the advantages of low cost,high integration,high print resolution,easy control and high ink compatibility,has expanded from conventional graphic printing to new areas such as electronics,mechanical engineering,life sciences.As part of an effort to develop piezoelectric inkjet technology and promoting the localization of such equipment,this paper aims at investigating a process for fabricating its actuator membranes of independent intellectual property rights.As a power source to inject droplet,actuator membrane affects the performance of Inkjet printing device.Inkjet printing technologies' origin and research status were known after referring to related literature both at home and abroad.And then the bend mode was chosen as the basis of our design in this paper.?1?The design of inkjet piezoelectric printhead.Assisted with theory analysis and finite element software simulation,this paper designed a multi-layer actuator membrane with its elastic layer of SiO₂,piezoelectric component of PZT?Lead zirconate titanate?,electrode of Pt,protective layer of Parylene C.Micro-Electro-Mechanical System?MEMS?was studied,and then the fabrication processes of inkjet piezoelectric printhead were chosen.?2?The fabrication of actuator membranes for inkjet piezoelectric printhead.Firstly the MEMS fabrication process was proposed according to the workability of materials as well as processes compatibility,and then optimized to obtain satisfactory actuator membranes.The etching rate and uniformity of SiO₂ layer were improved through adjusting its patterning bath temperature.The surface qualities of Pt electrodes were improved after modified the photolithographic process.The patterning process was optimized to diminish the lateral erosion of PZT.The rate of etching Parylene C was improved by adjusting the etching power to 100 w and adding the reactive gas CF4.Multi-step DRIE process was proposed to obtain vertical Si-cups and avoid the over-etching of SiO₂ layer.?3?The optimized process for releasing actuator membranes.With the multi-step DRIE process of 8/2,9/2,11/3 the actuator membranes were successfully obtained.The Si grass was eliminated by increasing the etching gas step by step.After balancing the rate of etching and passivation,the vertical Si-cups were obtained.Notching effect and the over-etching of SiO₂ were also avoided by decreasing the platen power to 0w.?4?The tests of actuator membranes.The vibration quality of the actuator membranes were tested using the VDD PC-Based Digital Vibrometer.After fabricating ink chamber using SU-8,the inkjet test was also carried out successfully with the droplets velocity of 5.6m/s and volume of 11 pl,proofing that the feasibility of this design and fabrication process.