About: Heat spreader is a(n) research topic. Over the lifetime, 13686 publication(s) have been published within this topic receiving 196268 citation(s).
01 Apr 1981-International Journal of Heat and Mass Transfer
Abstract: This study extends previous work of Bergles and Webb to establish a broad range of Performance Evaluation Criteria (PEC) applicable to single phase flow in tubes. The equations include the effects of shellside enhancement and fouling and are applicable to roughness and internally finned tubes. Detailed procedures are outlined to calculate the performance improvement and to select the ‘optimum’ surface geometry. PEC are presented for four design cases:(1) reduced heat exchanger material; (2) increased heat duty; (3) reduced log-mean temperature difference; and (4) reduced pumping power. The 11 cases discussed include fixed flow area and variable flow area. Appropriate PEC for two-phase exchangers area also discussed.
10 Jan 2005-Journal of Power Sources
Abstract: A detailed three-dimensional thermal model has been developed to examine the thermal behaviour of a lithium-ion battery. This model precisely considers the layered-structure of the cell stacks, the case of a battery pack, and the gap between both elements to achieve a comprehensive analysis. Both location-dependent convection and radiation are adopted at boundaries to reflect different heat dissipation performances on all surfaces. Furthermore, a simplified thermal model is proposed according to the examination of various simplification strategies and validation from the detailed thermal model. Based on the examination, the calculation speed of the simplified model is comparable with that of a one-dimensional model with a maximum error less than 0.54 K. These models successfully describe asymmetric temperature distribution inside a battery, and they predict an anomaly of temperature distribution on the surface if a metal case is used. Based on the simulation results from the detailed thermal model, radiation could contribute 43–63% at most to the overall heat dissipation under natural convection. Forced convection is effective in depressing the maximum temperature, and the temperature uniformity does not necessarily decrease infinitely when the extent of forced convection is enhanced. The metal battery case serves as a heat spreader, and the contact layer provides extra thermal resistance and heat capacity for the system. These factors are important and should be considered seriously in the design of battery systems.
01 Jul 2000-Applied Mechanics Reviews
01 Jan 1949-
07 Jan 2003-
Abstract: A bendable light emitting diode (LED) array in accordance with the present invention includes heat spreaders, dielectric material disposed above each heat spreader, and a bendable electrical interconnection layer disposed above these heat spreaders and electrically insulated from these heat spreaders by the dielectric material. At least one via passes through the dielectric material above each heat spreader, and at least one LED die is disposed above each via. The bendable electrical interconnection layer may be a lead frame comprising metal pathways that electrically interconnect some or all LED dice in series, in parallel, in anti-parallel, or in some combination of these configurations. Each via contains a thermally conductive material in thermal contact with the corresponding heat spreader below it and in thermal contact with the corresponding LED die above it. The LED dice may be thermally and electrically coupled to submounts disposed above corresponding heat spreaders in some embodiments.