A mechanical study on particulate reinforced polyamides for electronic encapsulations

• Main Author: Affreen, Shahnas
• Other Authors: Gan Chee Lip
• Format: Final Year Project
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/71673
• Institution: Nanyang Technological University

The use of engineering thermoplastics in the polymer industry today has grown in popularity and created higher demands for researchers and designers to come up with more cost efficient yet high-performance materials that can cater to a wide range of applications across several industries. Polyamide and its various blends are one of the many high-performance polymers commercialized in many demanding industries such as aerospace, electronics and defence. The use of inorganic particulate fillers in polymers have proved to further enhance the mechanical properties as well as lower the overall cost of engineering plastics. This project used Silica (SiO2), Alumina (Al2O3) and Aluminum Nitride (AlN) particle fillers to investigate its effects on the mechanical properties of polyamide as well as explore its use for electronic encapsulation applications, such as Integrated Circuit (IC) Packaging. Polyamides with varied filler concentration (i.e. 10vol%, 20vol% & 30vol%) of SiO2, Al2O3 and AlN fillers were prepared by twin screw extrusion method using optimized conditions. Microhardness Vickers indentation testing and lap shear tensile testing were carried out to investigate the effects of these filler types and its concentrations on the hardness properties and mechanical strength, where 30%vol concentration of fillers showed the most enhancement with SiO2 fillers giving the highest Hardness Value (HV) for Polyamide. Moreover, due to polyamide’s limitation of high moisture sensitivity, the effect of moisture absorption on the hardness properties of the polyamide samples were tested, where results showed a negative trend for all, except for Polyamide with AlN particle fillers. SEM images of the surface morphology, as well as the fracture surfaces of the polyamide samples, were also analysed, which further explained mechanical test results. A lap shear tensile test was also conducted as mechanical characterization and to test its adhesion. In addition, SOLIDWORKS 3D CAD design and simulation tests were carried out to study the design aspect of polyamide encapsulations, whereby smooth edges were shown to have reduced stress concentration, as compared to that of sharp edges.