Category Archives: heat

ATS’ Standard Board Level Heat Sinks for PCB

We’ve just released our new line of standard board level heat sinks. These stamped heat sinks are ideal for PCB application, especially where TO-220 packages are used. Available now through Digi-Key Electronics​ or at this link from ATS…


To play MIT’s Space Invaders Remix, click here…

ATS maxiGRIP and superGRIP Heat Sink Attachments

Advanced Thermal Solutions John O’Day and Len Alter showcase the patented heat sink attachments maxiGRIP and superGRIP. With its patented and discrete design, these heat sink attachments are well worth it for being your only choice for a cost-effective, high performing thermal solution.

The Importance of Heat Flux Sensors

Heat flux sensors are practical measurement tools which are useful for determining the amount of thermal energy passed through a specific area per unit of time. Measuring heat flux can be useful, for example, in determining the amount of heat passed through a wall or through a human body, or the amount of transferred solar or laser radiant energy to a given area.

Affixing a thin heat flux sensor to the top of a component will yield two separate values which are useful in determining the convection heat transfer coefficient. If the heat flux can be measured from the top of the component to the ambient airstream and if the temperature at the top of the component and of the ambient airstream is measured, then the convection coefficient can be calculated.


q = Heat flux, or transferred heat per unit area

h = Convection coefficient

TS = Temperature at the surface of the solid/fluid boundary

TA= Ambient airstream temperature

Using a heat flux sensor can be useful for lower powered systems under natural convection scenarios. Under forced convection, the heat lost to convection off the top of a component can often be significantly higher than the heat lost to the board, particularly if the board is densely populated and the temperature of the board reaches close to the temperature of the device. Under natural convection situations, often the balance of heat lost to convection and heat lost through the board becomes more even and it therefore is of even greater interest to the designer to understand the quantity of heat dispersed through convection.

Experiments done at Bell Labs alluded to the effect of board density on the heat transfer coefficient. In these experiments, thin film heat flux sensors are affixed to DIP devices which populate a board. The total heat generation of the board is kept constant, so the removal of components from a densely populated board only increases the heat generation per component. The results of this particular experiment highlight an increase in the ratio of heat lost through convection from the surface of the component as board density increases and individual device power decreases.

 Surface Heat Flow vs. Board Density

Qs/Qt = the ratio of total heat flow through device surface to total heat generation

σ = the ratio of total device surface area to total board area

If a board was to be sparsely populated, a greater percentage of heat can be transferred to the board due to larger thermal gradients; however since the overall surface area of the sum of devices decreases, to some extent the heat transfer coefficient must increase to reflect a balance. As the number of components decreases, the power generation increases per component, and the larger resulting temperature gradients in the region around the component yield more convective flow and thus an increase in the heat transfer coefficient. On the other hand, if the board becomes more densely populated, the proportion of heat transferred through the surface, as compared to through the board increases, and the overall increase in heat transferred through the surface yields increased flow and heat transfer at an individual component surface.

The use of a heat flux gauge is an important tool for the electronics designer. In particular, by using a heat flux gauge, it is possible to experimentally determine the heat transfer coefficient at a certain location on the electronics board where it would have had to be simply predicted or estimated previously. Due to the complexity of many electrical systems as well as the irregular nature of many boards, often analytical or CFD methods are not accurate and the best approach is empirical techniques. The use of the heat flux sensor can give results which would be difficult to calculate using analytical or numerical simulations. However, like most other instruments, it is important to use the sensor correctly and carefully to decrease the errors within a system and increase the reliability.

Heat Sink Selection Made Easy: an ATS Thermal Engineering Free Webinar 4/22 @ 2PM

As heat dissipation needs for electronic devices grow rapidly, choosing the right heat sink the first time is essential. With so many application requirements and heat sink options, this can be a daunting task. In this webinar, attendees will learn about the importance of system airflow and its impact on heat sink design; attachment methods and how to solve design challenges thermally and mechanically; and how to make the right custom or off-the-shelf heat sink choice for your application and budget. To register for this webinar, click to, “Heat Sink Selection Made Easy“.

How to implement liquid cooling at the chip level: liquid cooled microchannel heat sinks to the rescue!

Liquid cooled micro-channel heat sinks have been shown to be a very effective way to remove high heat load.  The single phase liquid cooled microchannel has been used in many performance critical applications such as laser diodes, RF power amplifiers and CPU cooling.  A two phase version offers even greater capacity to cool.   Click here to ATS’s QPedia white paper to read all about how to use them (yes, it’s free and written by ATS’s Thermal Engineering Team):  Critical Heat Flux of Boiling in Microchannels.