Preparation Of MEMS-based 4×4 Micro-array And Performance Study

A 4×4 micro-thruster was designed in this paper.Application of MEMS technology, ignition circuit layer, silicon chamber and external circuit board were produced,which make up of the micro-thruster. The performance of micro-thruster array was tested.Application of wet etching process, the Cr ignition bridge was produced. The best lithography conditions were confirmed. Completed the Al/CuO/Al film bridge by image-reversal process, The optimum parameters of AZ5214E reversal process and composite thin film deposition were confirmed. Tested the electrical properties of two thin film bridges. the average membrane resistance of Cr bridge was 270.64Ωand Al/CuO/Al bridge was 5.604Q;When ignited with constant voltage, the average blowing time of Cr bridge was 55.940μs and Al/CuO/Al Bridge was 2.793μs; the average blowing energy of Cr bridge was 296.3628μJ and Al/CuO/Al bridge was 97.884μJ. Cu ignition circuit was produced by wet etching process, the circuit line achieved 4×4 units logic ignition. We use P-type silicon to make combustion chamber by Anisotropic etching,which thickness of 398μm and (100) crystal face.Using LPVCD double-deposited Si3N4 film on the substrate surface as wet etching mask.Application of anodic bonding.silicon combustion chamber and ignition circuit layer was bonded., the ignition circuit layer and the outer circuit board was bonded by wire bonding. The optimum parameters of anodic bonding and wire bonding were confirmed.LTNR/adhesive was used as propulusion of micro-thruster array, the propulusion can completely combustion in constant voltage of 15V,20V and 25V. As the voltage increases, the ignition time decreases,the average ignition time of each voltage were respectively 1.21ms,1.79ms and 2.71ms; The average ignition energy of each voltage were respectively 3.41 mJ,3.34 mJ and 3.79 mJ.Unit thrust and impulse was tested with the si-chamber and cylindrical epoxy chamber,which has diameter of 0.7mm and thickness of 0.9mm or 1.2mm. With the combustion chamber volume increases, the unit thrust and impulse showed a tendency toincrease. The average thrust of three chambers were 57.15mN,412.02mN and 739.85mN; the average impulse were respectively 0.0385 mN·s,0.278 mN·s and 0.501mN·s.