Because the accurate determination of thermal conductivity is a demanding task (often not recognized by either designers or vendors), methods, based on the measurement of another physical property that is uniquely coupled to thermal conductivity, are very challenging. One such method is based on the so-called Wiedemann-Franz Law, which links the thermal conductivity to the … [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...]
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...]
Thermal conductivity of composite materials
A composite material can be defined as a material in which two or more different materials are bonded together. It is sensible to make a distinction between macrocomposites and microcomposites. The first group usually has a layered structure, and PCBs are the main application. The second group looks uniform to the naked eye; materials from this group are often used for packages … [Read more...]
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