The Research On The Properties Of Surface Acoustic Wave Devices And Implementation Based On Printed Electronics Technology

The research on PE(Printed Electronics) technology has been paid great attention in recent years. With the application of PE technology, many kinds of electronic products can be produced in large quantities which like printed paper products, such as various types of flexible storage and display devices, sensors and actuators, stretchable and bendable thin film solar cells etc.In this thesis, PE technology is applied in preparation of SAW(Surface Acoustic Wave)devices based on the research and the application of PE and SAW technology. The pattern of the device can be more flexibly implemented by using the PE technology. At the same time,the rapid development of metal nanoparticles ink and its wide use provide conditions for the application of PE technology to fabricate SAW devices.In the thesis, SAW filters were made by inkjet printing technology and screen printing technology. The main contents include filter design and simulation, process steps and parameter descriptions and SAW device performance testing and analysis of the results.The type of SAW filter is transversal type filter which has a single electrode, and the width of finger and the distance of two fingers are equal. Inkjet printing processes and screen-printing process are applied to preparate 50μm and 200μm SAW filter respectively,and piezoelectric materials contain quartz, LN and LT. The piezoelectric properties of three materials are compared and the performance of filters is tested.For the filter performance test, the morphology testing and electrical performance testing methods are used. The morphology test includes a microscope and test level meter, electrical performance testing contains the impedance test, signal transmission test and magnitude response using network analyzers.There is an error in the size of interdigital lines which made by the inkjet printing process in microscopic observation, the impedance of the interdigital electrodes between 0.3-2.0Ω measured with a multimeter, it has good conductivity, the thickness of the electrode is 0.3-0.5μm, the cycle of IDT is basically consistent with the design value, and the performance of filter with LN is achieved. The error of an interdigital line width which made by screen printing process is located between 50-100μm, the thickness of it is 5-10μm, and the performance of filter with LN and LT is achieved.In this thesis, a large number of theoretical analyses and experimental verifications show that the application of PE technology to prepare the SAW device is feasible. With LN as a piezoelectric substrate, the performance of an ink jet printing SAW filter is more prominent;with LN and LT as piezoelectric substrates, screen printing SAW filters realized the filter characteristics.Test results show that, although there is a gap of the SAW devices performance between the PE and microelectronics technology, and aspects of the preparation process of the device there is still much room for improvement, still the fact that the process of PE is simple,the equipment and production costs is inexpensive, the process does not produce waste,emissions and other harmful substances, it is suitable for mass production and other advantages made it have great research value and economic significance.