Introduction Mobile computing is poised to shape the way we live our lives, allowing people to generate, retrieve, and process data anywhere and at any time. The infrastructure for mobile computing is rapidly developing, as evidenced by the recent growth of cellular phone networks and a constant stream of innovations in portable electronic equipment. Mobile computing is also … [Read more...]
Interaction of the system and module-level thermal phenomena- a flip-chip/BGA example
Fig. 1: Levels in a computer environment. Introduction Increasing demands for higher performance in microprocessors have a direct effect on chip power and heat generation. Increased function and miniaturization of the packages result in thermal challenges that require a thorough understanding of the system's thermal performance under all possible field conditions. Regardless … [Read more...]
Coefficient of thermal expansion
As complexity increases and dies and packages become even larger, temperature gradients also increase, leading to problems with thermal mismatch. Hence, thermomechanical analysis grows in importance. Apart from the temperature differences, the most important parameter describing thermally induced stress is the coefficient of thermal expansion (CTE, or °), expressed in units of … [Read more...]
Packaging: designing for thermal performance
Figure 1. Various leadframe and BGA packages Introduction The well-established trend within the electronics industry to provide everincreasing computing power at less cost seems to defy the laws of economics.However, this industry has not been able to suspend the laws of physics. Eachcalculation by each of the millions of transistors in the modern personalcomputer is … [Read more...]
Electrical temperature measurement using semiconductors
Introduction Semiconductor junctions offer many useful properties including inherentcharacteristics which are well suited to temperature measurement. Within theelectronics cooling arena, these properties form the basis for "theelectrical method of junction temperature measurement" and are used formeasurement of junction temperatures within operating semiconductor devices. They … [Read more...]