Figure 1. Ceramic Package - Aluminum Heat SinkAssembly Introduction The exposed surface area of many of today's high powered electronic packagesis no longer sufficient for the removal of the heat generated during normaloperation. Heat sinks are a commonly-used, low cost means of increasing theeffective surface area for dissipating heat by means of convective air cooling.While … [Read more...]
Forced convection cooling of airborne electronics
Figure 1. AFT description Fin pitch = 25.01 per in = 985 per mPlate spacing, b = 0.200 in = 5.08 x 10-3 m Fin Length = 0.111 in = 2.8 x 10-3 m Flow passage hydraulic diameter 4rh = 0.004905 ft = 1.50 x 10-3 m Fin metal thickness = 0.004 in = 0.102 x 10-3 m Total heat transfer area/volume between plates, ß = 719.4 ft2 / ft3 = 2,360 m2 / m3 Fin area / total area = … [Read more...]
Thermal Conductivity
For most calculations regarding the thermal analysis of electronic systems, thermal conductivities of solid materials are required. It is felt that many designers would welcome a comprehensive list showing these values for certain classes of objects, such as PCB materials, leadframes, molding compounds, alloys etc.. This issue starts with 45 leadframe materials, the data for … [Read more...]
Microthermal imaging in the infrared
John McDonald, Latigo Optics and Grant Albright EDO/Barnes Engineering Division Introduction Infrared imaging methods provide unequaled ease and flexibility forinvestigating micro-circuit temperatures. The researcher need only slide thecircuit under the objective lens and power it up in order to measure thetemperatures throughout the micro-circuit at once, precisely and … [Read more...]
Notes on Using Thermocouples
Introduction Thermocouples are the most widely used temperature sensor in test anddevelopment work. Accurate temperature measurements can be made at low costwith shop-built probes and ordinary low-level voltmeters. What Are Thermocouples and How Do They Work? Any two wires of different materials can be used as a thermocouple ifconnected together as in Figure 1. The AB … [Read more...]
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