Here’s a series of questions our engineers walk through when faced with a new thermal mangement project that requires choosing the right heat sink.
Component or Device Details: This includes asking questions to determine the components power level (generally expressed in watts), maximum temperature (Case or Junction C), package size, package type (BGA, flip chip, etc.), package material, and package configuration (exposed die or heat spreader, etc.)
System Airflow: Is there a fan or blower? Is it ducted or unducted? Is it pushing air onto the area needing thermal management or pulling air over the component needing thermal management? Or is it convection cooled?
Space Constraints: What is the allowable height off the PCB? What is the maximum heat sink height allowed? Is heat sink overhang over the component allowed? If heat sink over hang isn’t allowed, would it be allowed if a heat sink were cut out in place to allow closely positioned heat sinks to not be effected (yet overhang would happen in other places).
System Operating Conditions: What is the known to be maximum ambient temperature outside the system? What is the allowed maximum ambient inside the system? Is there a maximum altitude in which the system may eventually operate? Are there shock and vibration specifications to be considered (such as in MIL, NEBS, or ETST)?
Attachment Method Allowed: What attachment method is allowed for the heat sink? Are there pre-drilled, “industry accepted” holes already so that a push-pin heat sink is allowed or is it preferred that there are no holes in the PCB? Can a clip be used? Is a clip needed for compression of thermal interface material or simply to attach a heat sink loosely? If a clip is okay, how much keep out area around the components is available.
Thermal Interface Material In this section we ask questions to determine the best thermal interface material to use. Choosing and applying the right thermal interface material can reduce case temperature by as much as 50% We’ll want to know if the component has any surface irregularities or all out roughness, and we’ll need to know the surface area of the contact area.
We’ll take answers from all the questions and use them to help us get a complete picture of the thermal requirements for a given project. Stepping through questions such as these can be a logical road map to doing some basic thermal analysis that can lead to the right heat sink for your application.
If you need a team to hep you through the engineering investigation phase or if you’ve been through that phase already and just need a heat sink that meets your specifications, contact ATS! You can learn more about us at our website http://qats.com or you can email us with your request sending mail to sales.hq@qats.com