topic Thermal Simulation of Circuit Board in Fusion Design, Validate & Document Forum

Thermal Simulation of Circuit Board

Anonymous — Fri, 15 Sep 2017 18:28:32 GMT

I have been trying to create a Thermal Simulation of a circuit board to see if the number of LEDs on the board will cause them to run too hot. I know the power to each LED is 4W, 1W of which is converted to light, and therefor 3W of the power will be lost as heat. I have these LEDs on an Aluminum board. For the sake of the initial model, I have simplified the LEDs to rectangular objects of one material, which I have chosen silver, because the pads of the LED are silver plated copper. This however is inconsequential to the question. Each of the LEDs in the simulation have the same material properties, and are given the same amount of power, which I have applied to the bottom face of the part, where it touches the Aluminum PCB, as an Applied Temperature of 3W. The PCB is set to all faces convection with values of 3.50 W.(m^2 C) and ambient temperature of 20C. Why is the thermal simulation rendering a gradient change in temperature right to left? All the LEDs are the same, they should have the same thermal properties.

I am just learning how to use the thermal simulation tool, so I am unfamiliar with how to choose which settings should be applied to which parts in order to achieve the desired effect. Can anyone recommend how to apply thermal loads to the LED parts, so that they transfer hear to the PCB board?

Re: Thermal Simulation of Circuit Board

John_Holtz — Mon, 18 Sep 2017 15:58:25 GMT

Hi @Anonymous Welcome to Fusion and/or simulation.

Your result shows essentially a uniform temperature: 67.55 to 67.57 F, a difference of only 0.02 degrees! That is well within the "round off error" of simulation!

In other words, the temperature gradient is not significant. You should be more concerned about why the LEDs do not heat up above the ambient temperature. That is probably related to how the analysis was setup. If you want to export your model to an F3D file and attach it to your post, someone will take a look at it and make some suggestions.

Re: Thermal Simulation of Circuit Board

Anonymous — Mon, 18 Sep 2017 17:54:49 GMT

Thanks @John_Holtz for your help so far. I have attached the file this time. As mentioned I am not experienced with this kind of simulation and it is quite possible that I have not applied the thermal loads correctly. I tried several different simulations before this one, and regardless of changes to the simulation, the thermals were never turning out as I had expected.