Introduction One of the more complex thermal problems in electronics is the modeling of complete systems, such as an enclosure containing electronic components. A typical example would be a power supply, including heat sinks and a cooling fan. This problem becomes more difficult when there are multiple heat sinks and other large components arranged in an arbitrary manner inside … [Read more...]
Calculating Spreading Resistance in Heat Sinks
Accident? Consider the scenario where a designer wishes to incorporate a newly developed device into a system and soon learns that a heat sink is needed to cool the device. The designer finds a rather large heat sink in a catalog which marginally satisfies the required thermal criteria. Due to other considerations, such as fan noise and cost constraints, an attempt to use a … [Read more...]
A simple method to estimate heat sink air flow bypass
Introduction After selecting or designing a heat sink based upon a given air velocity orvolumetric flow rate through the fins, the thermal designer needs to determinethe total amount of flow which must be delivered in the duct or card passagecontaining the module w with heat sink. As shown in Figure 1, some of the flowwill go around or bypass the heat sink. In fact, depending … [Read more...]
Thermal Interface Materials
Thermattach thermally conductive adhesivetapes Introduction Today's semiconductors, whether discrete power or logic ICs, are smaller,run faster, do more and generate more heat. Some microprocessors dissipatepower levels that were once the exclusive domain of discrete power devices,namely 10 to 25 watts. These power levels require thermal management techniquesinvolving large … [Read more...]
Applying computational fluid dynamics to heat sink design and selection
Abstract This article describes how Computational Fluid Dynamics (CFD) can help inthe selection and/or design of a heat sink for electronics cooling applications.CFD modeling complements the other tools in the thermal tool kit: calculationsbased on approximations and correlations; and experimental work. Whether theapplication includes single or multiple heat sinks, the … [Read more...]
