{"title":"Design considerations of high heat flux heat pipe evaporators","authors":"Z. Zuo","doi":"10.1109/STHERM.2001.915179","DOIUrl":"https://doi.org/10.1109/STHERM.2001.915179","url":null,"abstract":"A numerical model was developed to describe the liquid and vapor flows inside porous wicks in heat pipe evaporators. The evaporator design parameters, including pore radii distribution, wick permeability and thickness, were calculated for various heat flux conditions. The vapor fraction, defined as the percentage of wick volume occupied by the vapor, was found to be highly dependent on the pore radii distribution and critical in determining the heat flux limit of the evaporator. The model was compared to previous experiments and other models to verify its accuracy. It can be used for design of high heat flux heat pipes for cooling of high power electronics.","PeriodicalId":307079,"journal":{"name":"Seventeenth Annual IEEE Semiconductor Thermal Measurement and Management Symposium (Cat. No.01CH37189)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131320779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Batty, C. Christoffersen, S. David, A. J. Panks, R.G. Johnson, C. M. Snowden, M. Steer
{"title":"Fully physical time-dependent compact thermal modelling of complex non linear 3-dimensional systems for device and circuit level electro-thermal CAD","authors":"W. Batty, C. Christoffersen, S. David, A. J. Panks, R.G. Johnson, C. M. Snowden, M. Steer","doi":"10.1109/STHERM.2001.915149","DOIUrl":"https://doi.org/10.1109/STHERM.2001.915149","url":null,"abstract":"An fully analytical spectral domain decomposition approach to solution of the nonlinear time-dependent heat diffusion equation in complex volumes is introduced. Its application to device/circuit level electro-thermal simulation on CAD timescales is illustrated. The full treatment in coupled electro-thermal CAD of thermal nonlinearity due to temperature dependent diffusivity is described. Thermal solutions are presented in the form of thermal impedance matrix expressions for thermal subsystems. These include double Fourier series solutions for rectangular multilayers, which are an order of magnitude faster to evaluate than existing semi-analytical Fourier solutions based on DFT-FFT. They also include double Fourier series solutions for arbitrarily distributed volume heat sources and sinks, constructed without use of Green's function techniques, and for rectangular volumes with prescribed fluxes on all faces. These analytical solutions allow treatment of arbitrary device structures without invoking conventional numerical methods. They provide minimal boundary condition independent compact thermal models, allowing CAD timescale coupled electro-thermal solution for complex systems, without requiring lumped element RC network extraction or node reduction. The time-independent thermal resistance matrix description of device structure is illustrated by a fully physical, coupled electro-thermal study of the interaction of substrate thickness and surface convection in power HEMTs. The thermal time-dependent implementation is illustrated by circuit level harmonic balance simulation of a 3/spl times/3 MMIC amplifier array.","PeriodicalId":307079,"journal":{"name":"Seventeenth Annual IEEE Semiconductor Thermal Measurement and Management Symposium (Cat. No.01CH37189)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130005274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Poppe, G. Farkas, M. Rencz, Z. Benedek, L. Pohl, V. Székely, K. Torki, S. Mir, B. Courtois
{"title":"Design issues of a multi-functional intelligent thermal test die","authors":"A. Poppe, G. Farkas, M. Rencz, Z. Benedek, L. Pohl, V. Székely, K. Torki, S. Mir, B. Courtois","doi":"10.1109/STHERM.2001.915144","DOIUrl":"https://doi.org/10.1109/STHERM.2001.915144","url":null,"abstract":"Thermal characterization of IC packages and packaging technologies is becoming a key task in thermal engineering. To support this by measurements, we developed a family of thermal test chips that allows a wide range of possible applications. Our chips are based on the same basic cell that is mainly covered by dissipating resistors and also contains a frequency output temperature sensor. These basic cells are organized into arrays of different size. The arrays are designed so that larger arrays can also be built for tiling up larger package cavities. The first member of the family, TMC81, has been manufactured and measurements show that the goals aimed for at the design stage have been achieved.","PeriodicalId":307079,"journal":{"name":"Seventeenth Annual IEEE Semiconductor Thermal Measurement and Management Symposium (Cat. No.01CH37189)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125139335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}