Моделирование датчиков температуры мощных интеллектуальных ИС
The computational model of the temperature sensors integrated on the IC chip with power transistors is developed. The 2D/3D problem of sensor placement is mathematically described by the classic heat transfer equation coupled with the equation for current density distribution. It is shown that parasitic effects of sensor current displacement and thermo-emf generation resulting from a temperature gradients (Seebeck effect) must be taken into account. For this purpose the special differential equation is introduced. The examples of point- and strip-like temperature sensors modeling for power BJTs and ICs are demonstrated.
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.