In today's electronics equipment, total system dissipated power levels are increasing with every new design. Increases in power levels combined with the market expectation of reduced package sizes lead to heat problems that, if uncontrolled, can significantly shorten the life of the electronics. Although this "increased power - decreased size" scenario has been prevalent for … [Read more...]
The thermal conductivity of air
In the Technical Data column of ElectronicsCooling Magazine, September 1998, the thermal conductivity of gases in general has been discussed. A few sentences were devoted to the temperature and pressure dependence of the most common gases. For example, it was stated that above 0.001 bar, the increase in thermal conductivity is of the order of magnitude of 1% per bar increase of … [Read more...]
The treacherous streams
During the development of a telecommunications product, an unpredictable phenomenon of air streams within the maze of cards and module was encountered. It could only be compared to suddenly confronting powerful inner streams in a calm ocean. Unlike the ocean, however, these streams appeared in a man-made machine. It seemed as if someone had rewritten the laws of physics. It was … [Read more...]
Determining the junction temperature in a semiconductor package, part IV – localized heat generation on the die
In the standard thermal test environment, thermal test chips are designed to dissipate the applied power uniformly over most of the die surface. However, in many situations of practical interest, the power is dissipated over a localized area of the die. This column provides calculation methods to deal with the latter situation. Figure 1 illustrates the situation of interest … [Read more...]
High accuracy thermal interface resistance measurement using a transient method
Heat dissipation of active devices has become one of the limiting factors in further miniaturization. While component manufacturers succeed in decreasing the overall thermal resistance of their packages, the thermal interface resistance to the board becomes the next limiting factor. Therefore, understanding interface and contact resistances becomes increasingly important for … [Read more...]
- « Previous Page
- 1
- …
- 333
- 334
- 335
- 336
- 337
- …
- 354
- Next Page »
