Jingyan Fu

A TSV alignment design for multilayer 3D IC

Through-silicon via (TSV) achieves interconnects of multiple dies in a 3D IC. Previous researches show that irregular TSV placement may cause reliability issues in manufacturing. Therefore, this paper forwards a TSV alignment design in acquiring an overlap-free near-regular TSV placement. This design features a TSV alignment algorithm which aligns an irregular TSV placement into a near-regular one. Experiments are conducted on 2D-3D transformation of IBM benchmark circuits. Results show that this design successfully realizes a near-regular overlap-free TSV placement.

Thermal analysis and thermal optimization of through silicon via in 3D IC

The study on thermal problem of through silicon via has become an important part of the three dimensional integrated circuit. This paper proposes some thermal aware optimization measures of TSV to optimize thermal performance of 3D IC. Thermal performance simulations on different TSV distribution, different TSV structure parameter and different TSV cluster are done respectively. Through the simulation and analysis, qualitative, quantitative results and thermal optimization measures are presented. According to the result, optimization could be done in EDA software.

Simplified empirical formula on TSV thermal analysis for 3D IC EDA

In this paper, based on the formulas of the classic theory of heat conduction, proposed a temperature distribution formula in the three-dimensional space, which can effectively and accurately calculated the temperature value at any coordinate-point within the TSV (Through Silicon Via) model. By simulating the behavior of heat conduction and analyzing temperature data, this paper proposed the simplified empirical formula of temperature distribution for analyzing in 3D IC, and compared the calculated value with the simulation value to validate. These results will be easy to estimate the range of temperature change for EDA toll.

Time-varying algorithm for swarm robotics

Ever since the concept of swarm intelligence was brought out, a variety of control algorithms for swarm robotics has been put forward, and many of these algorithms are stable enough and efficient. Most of the researches only take an invariable controller which functions through the whole stage into consideration, the situation in which controller changes over time is rarely taken into account. However, there are limitations for invariable controller dominated algorithms in practical situation, which makes them unable to meet changing environment. On the contrary, variable controller is more flexible and can be able to adapt to complex environment. Considering such advantages, a time-varying algorithm for swarm robotics is presented in this paper. The algorithm takes time as one of the independent variables so that the controller is no longer fixed through the time, but can be changed over time, which brings more choices for the swarm robot system. In this paper, some relevant simulations are designed to test the algorithm. Different control strategies are applied on the same flock during the time, and a more complex, flexible and practical control effect is acquired successfully.

On-chip thermal management method based on phase change material

Phase change materials (PCMs), as a thermal storage unit, have been used in thermal management area for integrated circuits (ICs). However, the heat dissipation from the chip to PCM-based heat sink needs much long time which greatly suppresses cooling effect of PCMs. In this paper, a new package frame with PCM directly touching top of the chips inside the package cavity instead of using PCM-based heat sink is proposed to accelerate this heat dissipation process. The proposed model is verified by carrying out simulations and experiments. To obtain more precise experimental results, the extra tiny thermocouple and chip-level heat generators are utilized. The results show 2°C–5°C temperature reductions under 300 mW–800 mW input which proves the effectiveness of the proposed approach. Whats more, this method can be easily combined with other thermal management methods to further alleviate the thermal problem of the chips.

A novel thermal-aware structure of TSV cluster

Although thermal-aware TSV (Through Silicon Via) clusters behavior has been studied extensively, the structure of TSV cluster, which is also important to thermal problem in 3D IC (Three Dimensional Integrate Circuit), is ignored. In this paper, a novel structure of TSV cluster is proposed to improve the thermal performance of 3D IC. Models have been established to study the effect of TSV clusters structure on thermal performance in 3D IC. Simulation results show that the proposed TSV clusters structure improves the thermal performance of 3D IC, which can help to alleviate the thermal problem.

A thermal-aware distribution method of TSV in 3D IC

Thermal problem is serious in 3D IC since its high power density. Through Silicon Via (TSV) becomes a main heat dissipation path because of the relatively high thermal conductivity as compared to silicon substrate. To efficiently manage thermal-aware TSV distribution, in this paper an equilateral triangle grid distributing method is proposed and is tested on a benchmark. Finite element models are established to study the advantage of this method. It is concluded that under the same condition, the average temperature of equilateral triangle grid distribution is optimized up to 0.9% than square grid distribution in tested model groups.