Study On Thermal Optimization Of 3D IC TSV Cluster On Variable Signal And Circuit

After decades of rapid development,semiconductor integrated circuits are severely constrained by the size of components,chip functions,cost-effectiveness and other aspects.As a new design method of system-level architecture,the development of three-dimensional integrated circuits(3D IC)is attracting a plenty of attention.Among the challenges faced by 3D IC,the heat problem is one of the most urgent problems to be solved.Through silicon via(TSV)is the communication path between layers of 3D IC.It is also an important heat conduction path.The heat problem of 3D IC can be alleviated by the reasonable TSV distribution design.While due to the difference of the working state of different parts of the chip,the hotspot distribution in the 3D circuit are irregular and unstable,and the fixed TSV position cannot alleviate the dynamic hot spot.To solve this problem,through the thermoelectric analysis of TSV cluster along with the design of TSV cluster measurement and control circuit and TSV cluster switching algorithm,the thermal optimization method of the variable signal mechanism of 3D IC TSV cluster and measurement and control circuit are proposed in this paper.The main work is as follows:In this paper,the thermoelectric analysis method of TSV and the model of TSV are analyzed and studied.The simulation method and simulation flow used in this paper are presented,and the TSV model is established based on the finite element simulation software(COMSOL).The thermal conductivity calculation model and equivalent electrical model of TSV used in the study of thermal and electrical distribution of 3D IC are analyzed,which lays a foundation for the proposal of variable signal mechanism.In this paper,through the analysis of thermoelectric coupling of TSV cluster,a method of alleviating the hot spot of chip by variable signal mechanism of TSV cluster is proposed.Based on TSV model and equivalent electrical model,the model of TSV cluster is established.Through calculating and comparing,appropriate boundary conditions are applied to the model and the thermoelectric distribution is analyzed.The difference of thermoelectric distribution of chip under different boundary conditions is explored,and the variable signal mechanism of TSV cluster is proposed based on the conclusions.In this paper,the method of TSV cluster variable signal mechanism to alleviate chip hot spots is validated and analyzed.The effects of heat source switching and electrical signal switching between TSV clusters on the thermal distribution of 3D IC are studied.The variable signal mechanism of TSV cluster is validated and optimized by exploring the influence of the diameter,height and spacing of a single TSV cluster,the spacing of each TSV cluster,and the signal switching in each layer of 3D IC on the mechanism.In this paper,the TSV cluster measurement and control circuit is designed and the TSV cluster signal switching algorithm is proposed.The TSV cluster measurement and control circuit uses CMOS temperature monitoring circuit to monitor the chip's hot spot changes in real time,and uses CMOS switch gate circuit to realize signal switching as well as to redistribute the TSV cluster signal path.The TSV cluster signal switching algorithm improves the signal switching scheme and achieves the overheated TSV cluster switching.In this paper,the temperature monitoring circuit is taped out under TSMC 0.18?m process,then the actual chip is tested.The area of the chip is 600?m×700?m.When the temperature reaches 55.5 degrees Celsius,the output voltage on the TSV cluster decreases,which realized the mitigation of hotspot by variable signal mechanism of TSV cluster.The research in this paper effectively alleviates the heat problem of the chip while retaining the chip's original structure and TSV distribution.Therefore,this study has a reference significance in the research and application of thermal management of 3D chips.