The Study On Fabrication Technology Of Piezoelectric Inkjet Chamber

The digital printing of inkjet has been gradually extended to biomedical,ceramic building materials,textile printing and dyeing industries.The manufacturing technology of piezoelectricity inkjet printing head is the key technology that needs to be breakthrough in China.In this paper,the fabrication technology of the ink-jet chamber of the piezoelectric inkjet printing head is studied,and the main contents are as follows:(1)The structure and working principle of each part of the inkjet print head are introduced,and the structure of the inkjet chamber and the shape of the jet hole are determined;According to the working performance requirements of the inkjet chamber,the commonly used materials in the field of micro electro mechanical devices are analyzed,and the polymer SU-8 is selected as the structural material of the inkjet chamber;The crosslinking mechanism of SU-8 was analyzed.The SU-8 adhesive with different crosslinking degree could be controlled by exposure parameters and post drying parameters.The thermal bonding process was determined to bond the fully crosslinked open chamber with the weakly crosslinked macroporous layer and orifice plate.The process flow of preparing the integrated SU-8 inkjet chamber was described.(2)In order to solve the problem of cavity blockage caused by orifice collapse,the structure of adding thick SU-8 macroporous layer was proposed,and the process flow of preparing macroporous layer was determined;According to the fracture failure principle of materials,the distribution of stress and displacement in thick SU-8 macroporous layer is simulated by COMSOL,and the structure of thick SU-8 macroporous layer is optimized.The maximum thermal stress is reduced by 60.3%,the maximum displacement is reduced by 50.5%,and the final bonded silicon substrate has no cracks.(3)According to the three ways of optical exposure,the method of adjacent exposure is selected to fabricate the inverted cone orifice plate by photolithography,and the large hole diameter is about 40 ?m.The hole diameter is about 27 ?m;In order to solve the problem of low through-hole rate in photolithography,the reverse conical orifice plate was prepared by hot embossing.The preparation processes of silicon impression,metal impression and PDMS impression were explored.The uniform size reverse conical orifice plate was prepared by hot embossing with PDMS impression.(4)The viscoelastic properties and interfacial bonding mechanism of the polymer were analyzed,which provided a theoretical basis for bonding quality analysis;The parameters of oxygen plasma treatment open chamber,bonding temperature and bonding time were optimized by experiments;The ink-jet chamber is tested by filling ink.The bonding chamber array has zero crosstalk and achieves 100% adhesion rate.