An Introductory Study On Fabrication Of Piezoelectric Ceramic

This thesis gives a quite detailed overview of piezoelectric ceramics. It will be beneficial to general reader to get basic ideas about this smart material once the reader going through this thesis. The scope of this work is limited to the development of ceramic piezoelectric, related to the scope of work which the objectives of the study are to focus on its manufacture of the green material, the poling process and the study of its physical and electrical characteristics. Processing of Barium Titanate (BaTiO3) ceramic by mixed oxide method for high technology applications involves the sequential steps; (a) powder preparation (b) powder calcining (c) de-agglomeration (d) forming (e) sintering (f) electroding (g) and poling. Each step is critical to the realization of desirable structure property relationships. To this end of the thesis, I have presented a brief introduction of the history of piezoelectric ceramics and a discussion on processing of the Barium Titanate ceramic (BaTiO3) and testing of the ceramic that define the behavior of a piezoelectric material. The ceramic was manufactured using Barium Carbonate (BaCO3) powder and Titanium Oxide (TiO2). The testing was done by using oscilloscope (waverunner) to observe the characteristic of piezoelectric ceramics. This work is organized as follows: in chapter 2 the previous work of processing a piezoelectric ceramic. Chapter 3 details the apparatus and experimental procedures used to fabricate and testing of piezoelectric ceramic. The result and discussion of the work are presented in chapter 4. To understand the behavior of a piezoelectric polycrystalline ceramics, we should know the principle of natural crystal like Quartz, Rochelle salt, and Tourmaline. Quartz crystal is naturally piezoelectric material and polycrystalline ceramic is an artificially polarized that manufactured material

Structural Analysis and Material Characterization of Silver Conductive Ink for Stretchable Electronics

Stretchable electronic systems have become more popular in various applications such as medical, fabric, flexible sensors for personalized health care, etc. There are two major parts of flexible and stretchable circuit boards that are substrate (a plastic material) and conductive ink (formulated polymer with conductive metal). According to electrical measurements, conductive ink plays a very important role in stretchable electronic equipment. The main objective of this paper is to develop a silver (Ag) based conductive ink and characterize its mechanical and electrical properties. Conductive ink is prepared by mixing an epoxy resin, cross – linking agent, additives (adhesion promoter), organic solvent, catalyst and silver flakes all together. ASTM D412 Type C dog bone shaped cutter is used to make three samples of conductive ink. The stress-strain analysis of conductive ink is carried out using universal testing machine (UTM). The conductivity is measured using two-point probe digital multi-meter. Also, the microstructural analysis, morphology and characterization are done by scanning electron microscopy (SEM). The images are taken after curing and tensile testing. The formulated ink possesses high conductivity and stretchability up to 137% strain. The achieved conductivity of the ink is 4.167×104 S/m. The maximum stress before failure, yield stress, Young’s and tangent moduli are calculated as 1.195 MPa, 0.86 MPa, 5.72 MPa and 2.08 MPa, respectively. The SEM analysis indicates that the distribution of silver particles is uniform and in a good density throughout the sample

Structural Assessment of Lead Free Solder Joint of Miniaturized Electronics Assembly

This paper presents a study on structural assessment of ultra-fine package assembly with nano-composites lead free solder joint after reflow soldering process. In this work, various nanoparticles (i.e. TiO2, Fe2O3 and NiO) with different weightage percentage (i.e., 0.01, 0.05 and 0.15 wt.%) were successfully incorporated into SAC305 solder paste using the mechanical solder paste mixer to synthesize novel lead-free composite solders. Effects of the nanoparticles addition on the quality of joining and fillet height between various weightage (wt.%) for the ultra-fine package assembly in the reflow soldering process have been investigated after the reflow soldering process by using the scanning electron microscope (SEM) system equipped with an energy dispersive X-ray spectroscopy (EDS) and XTV 160 x-ray inspection system. The experimental results show the increment of TiO2, Fe2O3 and NiO nanoparticles addition to 0.15wt.%, 0.05wt.% and 0.01wt.%, respectively, produce highest fillet height of each composition of nanoparticles solder paste. Among all these new composition of nanoparticles solder paste, NiO nanoparticles reinforced solder paste with 0.01wt.% yielded highest fillet height The miniaturized solder joints do not cause any problem in terms of solder voids. The findings show the capability of the reflow soldering process in assembling miniaturized electronics assembly and expected to provide a reference in electronic package industry