Modelling & Evaluation of EM Effect of Metal Fills used in IC Technology

Nowadays, recent Integrated Circuit Technology demands a minimum metal fill inclusion across the entire die of each functional layer to have uniform planarity. It is challenging to numerically simulate the real structure using Electromagnetic (EM) solvers because the mesh size of an EM solver is inversely proportional to the number of vertices in the layout and the inclusion of these metal fills has a significant impact on these vertices and increases mesh size. It is important to understand the metal fills do have an impact on the RF performance of the component and the impact becomes stronger as the frequency increases due to the parasitics and hence we cannot neglect it. Therefore, a Design Flow Methodology is studied and analyzed to take into account the effect of metal fills without penalty in accuracy and simulation time. The second part of the thesis focuses on two different approaches that can be used to extract the complex parameters providing the electromagnetic response of the layers, i.e. electrical permittivity and magnetic permeability. First, we describe the Quasistatic approach to extract the epsilon parameters from the capacitance and inductance. After, describing some of the limitations of this approach we focus on the Oblique Incidence Method as reported in the literature to extract the complex epsilon tensor parameters. The third part of the thesis looks into the Design Flow Methodology that embeds the Oblique Incidence Method into the design flow for 3D EM solvers to take into account the effect of metal fills. The 2.5D EM solver takes into account a scalar number which is less accurate and hence an insight of how the solution from the Oblique Incidence Method can used to extract a scalar number for the effective parameters and therefore be implemented in 2.5D EM tools is discussed.The fourth part of the thesis shows the validation of the Oblique Incidence Method for the 3D EM tool for two test cases which are wave propagating structure and lumped structure namely Grounded Coplanar Waveguide (CPWG) and Stacked Transformer. Validation of the Scalar Number Approaches for the 2.5D EM Tool was done for the CPWG structure.Finally, a brief study on the Design Based Approach is conducted with different metal fill shapes and alignment by using the Oblique Incidence Method by making use of 3D EM tool. This approach provides a better understanding of the epsilon variations for different metal fill shapes and that for less epsilon variations, an accurate scalar number value can be extracted to enable 2.5D EM simulations with improved accuracy.Electrical Engineerin

CAD-Enhanced Workspace Optimization for Parallel Manipulators: A Case Study

Abstract—The challenges of workspace determination of parallel manipulators (PMs) arise principally from the lack of analytical solutions of the forward kinematics. The inverseposition kinematics based approach for determining workspace tends to be inefficient, time consuming and unsophisticated. In this paper, we present a geometry-based method for accurate and computationally effective calculation of the workspace of a constrained parallel manipulator. We illustrate how boolean geometric operations can simplify the process of finding the workspace and optimizing the designs. Comparative performance studies, in terms of accuracy and computational performance, are performed to benchmark the approach against more conventional methods. Finally, we examine ways to further automate the process using a CAD package. I

Greener Operations: a James Lind Alliance Priority Setting Partnership to define research priorities in environmentally sustainable perioperative practice through a structured consensus approach

Objectives: To agree on the ‘top 10’ research priorities for environmentally sustainable perioperative practice. Design: Surveys and literature review; final consensus workshop using a nominal group technique. Setting: UK-based setting. Participants: Healthcare professionals, patients, carers and the public. Outcome measures: Initial survey—suggested research questions; interim survey—shortlist of ‘indicative’ questions (the 20 most frequently nominated by patients, carers and the public, and healthcare professionals); final workshop—ranked research priorities. Results: Initial survey—1926 suggestions by 296 respondents, refined into 60 indicative questions. Interim survey—325 respondents. Final workshop—21 participants agreed the ‘top 10’: (1) How can more sustainable reusable equipment safely be used during and around the time of an operation? (2) How can healthcare organisations more sustainably procure (obtain) medicines, equipment and items used during and around the time of an operation? (3) How can healthcare professionals who deliver care during and around the time of an operation be encouraged to adopt sustainable actions in practice? (4) Can more efficient use of operating theatres and associated practices reduce the environmental impact of operations? (5) How can the amount of waste generated during and around the time of an operation be minimised? (6) How do we measure and compare the short-term and long-term environmental impacts of surgical and non-surgical treatments for the same condition? (7) What is the environmental impact of different anaesthetic techniques (eg, different types of general, regional and local anaesthesia) used for the same operation? (8) How should the environmental impact of an operation be weighed against its clinical outcomes and financial costs? (9) How can environmental sustainability be incorporated into the organisational management of operating theatres? (10) What are the most sustainable forms of effective infection prevention and control used around the time of an operation (eg, personal protective equipment, drapes, clean air ventilation)? Conclusions: A broad range of ‘end-users’ have identified research priorities for sustainable perioperative care