Thermally-Aware Power Distribution Networks for Vertically Integrated Systems

Electronic products have played an overarching role in our societies. The evolution of portable and handheld devices in the past two decades has further augmented the pervasiveness of electronics into our daily activities. In general, the majority of modern electronic products require a heterogeneous set of components. These products include common portable devices or sophisticated systems used in medicine and industry for safety, monitoring, prevention, or therapy. This system heterogeneity will be intensified in the future, since the primary demand for faster processing of the information is augmented by the requirement for accurate sensing and detection of environmental stimuli.
Although these devices have created a flourishing market, the design of high performance and low power computing systems beyond consumer demands remains an omnipresent challenge. The design of more powerful computers is driven not only by the need to answer important scientific questions but also to address new or on-going societal needs. A characteristic example is the data-centers which they offer a variety of services but the relating energy-cost is increasing at an alarming rate. To mitigate these issues scientists and researchers explore disruptive technologies. A promising technology is three-dimensional (3-D) or vertical integration. This emerging technology has appealed to both industry and academia for several reasons. For example, considering the case of portable products, a vertically integrated system can drastically reduce the size of the board, which hosts the various components, by stacking these subsystems into a multi-tier structure reducing the overall size and improving power consumption.
This project will contribute to the evolution of vertically integrated systems by providing new design techniques and innovative analysis tools for the power distribution network of these systems. To better explain the complexity as well as the significance of this task, consider the power grid that supplies our residences. A similar yet severely constrained grid provides current to each transistor within an integrated circuit. The design complexity of this network for vertical multi-tier circuits is much higher similar to the case where the electric installation of a multi-storey building is much more complicated than that of a house. The scale of the problem where billion of "consumers" (i.e. transistors) must be provided with abundant current underlines the need for faster and accurate analysis methods. In this project, the analysis will be complemented by optimization methods, as the resources for the power network are limited and compete with other resources. Using our civic analogy, think of a situation where phone and power cables compete for a limited open space.
Efficient solutions to this problem cannot resort solely to existing design methodologies and/or numerical techniques due to the size of the problem as well as the heterogeneity of the envisioned vertical systems. The proposed research therefore aims at advancing the analysis and design methods of power networks for integrated systems while considering the particular traits and constraints relating to these systems. The results of the project will boost this emerging technology, bringing vertical integration a stride closer to economical high-volume manufacturing.

The project will have an explicit impact on design technologies for future multi-functional systems including primarily but not limited to electronic components. The immediate impact will be to augment analysis and design capabilities for the interested stakeholders. Within UK prominent corporations, such as ARM and Imagination technologies can exploit the outcomes of the project to ascertain the benefits of vertical integration for their future products. In addition, UK small and medium size enterprises (SMEs), such as Silvaco can benefit from the project. Silvaco is active in design automation and the investigated numerical algorithms and devised techniques, such as the monolithic vs partitioned approach in addressing multi-physics problems can be useful in those tasks that have high computational requirements. Maintaining the strong position of these established companies and leveraging the growth of SMEs within UK translates to a healthier economic environment for the British citizens. To further emphasize this point, consider that the new research framework Horizon 2020, recently launched by the European Union, includes a funding instrument exclusively for enhancing the development of SMEs and other provisions for economic growth through innovative research across Europe. Consequently, the proposed project is on the right track benefitting to the extend it can the electronics sector which currently contributes to 5.4% of the national GDP, employing about 850,000 across UK according to the report on Electronics Systems Challenges and Opportunities (ESCO). This report was composed by senior representatives of the British electronics industry and the Department for Business Innovation and Skills.
The success of this project will guarantee the design of highly robust vertical systems paving the way for the establishment of 3-D integration as a mainstream technology in semiconductors industry. Consequently, the implicit societal impact of the project will be considerable as this technology presents unique opportunities for energy-efficient computing, multi-functionality, and miniaturized products. These products in turn will satisfy customer demands but also contribute to important aspects of our lives including well-being, health care, and wellness. The distinct feature that vertical systems have and which also drives this research effort is that these systems can potentially provide the means to meet these social objectives with a smaller energy overhead and manufacturing cost as compared to state-of-the-art technologies.