Оценка эффективности теплоотвода BGA корпусов ИМС с помощью квазитрёхмерного теплового моделирования на ЭВМ
We consider the problem of manipulability of social choice rules in the impartial anonymous and neutral culture model (IANC) and provide a new theoretical study of the IANC model, which allows us to analytically derive the difference between the Nitzan-Kelly index in the Impartial Culture (IC) and IANC models. We show in which cases this difference is almost zero, and in which the Nitzan-Kelly index for IANC is the same as for IC. However, in some cases this difference is large enough to cause changes in the relative manipulability of social choice rules. We provide an example of such cases.
The quasi-3D BGA package thermal model is proposed. The general 3D heat transfer problem is correctly transformed to the set of 2D equations for temperature distribution in different layers of BGA package construction. It is shown that quasi-3D model provides the reasonable accuracy for standard and thermally enhanced BGAs. The software tool OVERHEAT-BGA is developed to obtain an numerical solution with considerably (6 – 10 times) reduced CPU time in comparison with universal 3D simulators.
The good agreement between designed and measured temperatures for standard and XP BGA packages is achieved.