An earlier work by the authors (Molki et al., 1995) discussed the adiabatic heat transfer coefficient of rectangular blocks situated in an in-line array. In real circuit boards, heat is generated by a number of electronic components. The temperature of each component is affected by two factors, self-heating and thermal wake effect. Self-heating is the temperature rise due to … [Read more...]
Determining the junction temperature in a semiconductor package, part III the use of the junction-to-board thermal characterization parameter
In recent issues, this column has dealt with the use of a number of thermal metrics to calculate the junction temperature of integrated circuits under various conditions. These metrics explored were JA, JC, and JT. To summarize the uses of these metrics: JA represents the junction-to-air thermal resistance for a package tested in an industry-standard test environment. It is … [Read more...]
Application of Thermoelectric Coolers for Module Cooling Enhancement
Figure 1. Cooling power density for different T.E. cooler designs (adaped from Vandersande and Fleurial [6]). Introduction Many advances in computer technology have been made possible by increases in the packaging density of electronics. These advances began with the introduction of the transistor in 1947 and continue today with ultra-large scale integration at the chip level … [Read more...]
Low Noise Axial Fan Applications
There are three basics to creating low-noise axial fan applications: airflow path design initial fan design analysis and correction of specific acoustical responses in the physical model Each is important and contributes to the overall sound levels of the program. Figure 1. Representative flow-versus-pressure characteristic of system air path.A flow-versus-pressure … [Read more...]
A system level cooling solution for cellular phone applications
Improving thermal performance of electronic components is very challenging due to the increasing power density and decreasing module sizes. The design trade off between electrical and mechanical characteristics and the cost of manufacturing MCM products requires innovative solutions to improve device thermal performance. The primary cooling path in portable electronics serves … [Read more...]
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