This project was concerned with the development of a finite element model capable of simulating a drop-impact event of handheld radio devices. Handheld radios call for exceptional robustness and reliability due to their deployment in critical applications. The development of a drop-impact finite element model aims to provide greater understanding of impact behaviours, this insight would ultimately be used to develop more robust and optimised handheld electronic products. Before such analysis tools can be introduced into the product development cycle an understanding of finite element methods, of setup parameters for the finite element solver and the accuracy of simulation results must be considered. Experimental results were used throughout the project to validate the finite element models developed. A drop-impact test rig was designed and constructed to control both impact orientation and velocity of the handheld radios tested. Drop-impact modelling of a handheld radio is extremely challenging because of the complex interaction of the contacting surfaces, the complex stress-strain and damping characteristics of the materials, and the excitation of the high frequency modes. For this reason, the finite element model was developed in two stages: a simplified radio was used to develop the understanding of the above complexities and then the understanding implemented in a more detailed radio model. The mesh size of the finite elements, the elastic and the damping characteristics of the materials and the contact conditions for the simplified radio model were varied to understand their influence on the simulation results. The finite element input settings and parameters were altered to give better agreement with the experimental results of the simplified radio model. The detailed radio was subsequently modelled. The lessons learnt from the simplified radio model were applied to the analysis of the detailed radio assembly. Despite general agreements, there were some differences between the finite element and experimental results which was attributed to the high complexity of the model. The project delivered a workable finite element model capable of analysing the drop-impact event of handheld radio devices. Suggestions have been provided that would further improve the quality of the model.

Recent trends to miniaturized systems such as smartphones and wearables, as well as the rise of autonomous vehicles relying on all-electric and smart in-car systems, have brought unprecedented needs for superior performance, functionality, and cost requirements. Transistor scaling alone cannot meet these metrics unless the remaining system components such as substrates and interconnections are scaled down to bridge the gap between transistor and system scaling. In this regard, 3D glass system packages have emerged as a promising alternative due to their ultra-short system interconnection lengths, higher component densities and system reliability enabled by the tailorable coefficient of thermal expansion (CTE), high dimensional stability and surface smoothness, outstanding electrical properties and low-cost panel-level processability of glass. The research objectives are to demonstrate board-level reliability of large, thin, glass packages directly mounted on PCB with conventional BGAs at pitches of 400µm SMT and smaller. Two key innovations are introduced to accomplish the objectives: a.) Reworkable circumferential polymer collars providing strain-relief at critical high stress concentration areas in the solder joints, b.) novel Mn-doped SACMTM solder to provide superior drop test performance without degrading thermomechanical reliability. Modeling, package and board design, fabrication and reliability characterization were carried out to demonstrate reliable board-level interconnections of large, ultra-thin glass packages. Finite-element modeling (FEM) was used to investigate the effectiveness of circumferential polymer collars as a strain-relief solution on fatigue performance. Experimental results with polymer collars indicated a 2X improvement in drop performance and 30% improvement in fatigue life. Failure analysis was performed using characterization techniques such as confocal surface acoustic microscopy (C-SAM), optical microscopy, X-ray imaging, and scanning electron microscopy/energy dispersive spectrometry (SEM/EDS). Model-to-experiment correlation was performed to validate the effectiveness of polymer collars as a strain-relief mechanism. Enhancement in board-level reliability performance with advances in solder materials based on Mn-doped SACMTM is demonstrated in the last part of the thesis.The studies, thus, demonstrate material, design and process innovations for package-to-board interconnection reliability with ultra-thin, large glass packages.

Conventional solder balls used in microelectronic packaging suffer from thermo- mechanical damage due to difference in coefficient of thermal expansion between the die and the substrate or the substrate and the board. Compliant interconnects are replacements for solder balls which accommodate this differential displacement by mechanically decoupling the die from the substrate or the substrate from the board and aim to improve overall reliability and life of the microelectronic component. Research is being conducted to develop compliant interconnect structures which offer good mechanical compliance without adversely affecting electrical performance, thus obtaining good thermo-mechanical reliability. However, little information is available regarding the behavior of compliant interconnects under shock and impact loads. The objective of this thesis is to study the response of a proposed multi-path compliant interconnect structure when subjected to shock and impact loading. As part of this work, scaled-up substrate-compliant interconnect-die assemblies will be fabricated through stereolithography techniques. These scaled-up prototypes will be subjected to experimental drop testing. Accelerometers will be placed on the board, and strain gauges will be attached to the board and the die at various locations. The samples will be dropped from different heights to different shock levels in the components, according to Joint Electron Devices Engineering Council (JEDEC) standards. In parallel to such experiments with compliant interconnects, similar experiments with scaled-up solder bump interconnects will also be conducted. The strain and acceleration response of the compliant interconnect assemblies will be compared against the results from solder bump interconnects. Simulations will also be carried out to mimic the experimental conditions and to gain a better understanding of the overall response of the compliant interconnects under shock and impact loading. The findings from this study will be helpful for improving the reliability of compliant interconnects under dynamic mechanical loading.

This thesis is focussed on designing of the air drop labradory for testing the balistic recovery systems. The first part of the thesis describes balistic recovery systems, their parts as well as methods of testing this devices. In the second charter there is a description of older vision of a testing device and simple test with the electronics of the testing device. The next step is designing of the new koncept of testing device and the structure analysis of the frame. The product of the thesis is a modular automated testing device, which is able to test balistic recovery systems for aicrafts with the weights between 230 and 1700 kilograms.