# How to Determine Maximum Allowable Heat Rate for Electronics Packages

## What is the maximum allowable heat rate that can be generated by the electronic device for an unfinned package?

1.30×10 W is the maximum allowable heat rate that can be generated by the electronic device to maintain the temperature below 85°C for an unfinned package.

## Calculation for Maximum Allowable Heat Rate:

The equation for conduction resistance is Rcond = d/kA (1), where d is the thickness of the material, k is the thermal conductivity, and A is the cross-sectional area.

Using the given values and substituting them into the equation, we find: Rcond = 100×10⁻⁹/490×(10×10⁻⁶)^2 = 2.04 K/W.

The equation for convection resistance is Rconv = 1/hA, where h is the heat transfer coefficient of the coolant and A is the cross-sectional area.

Substituting the values, we get: Rconv = 1/10⁵x(10x10⁻⁶)^2 = 1×10⁵ K/W.

Now, we can calculate the heat rate using the formula q = (T1 - Tinfinity) / (Rcond + Rconv) (3).

After substituting the values and solving the equation, we find that the maximum allowable heat rate is 1.30×10 W.

## Explanation of Calculation:

In order to determine the maximum allowable heat rate for the electronic device in an unfinned package, we first calculate the conduction resistance and convection resistance. By using the given values for the thermal conductivity of Silicon carbide, the dimension of the electronic device, and the heat transfer coefficient of the coolant, we can plug these values into the respective equations for resistance.

Once we have calculated the conduction and convection resistances, we can then use the formula to find the heat rate. This heat rate value helps us determine the maximum allowable heat rate that can be generated by the electronic device to maintain the temperature below 85°C for the unfinned package.

Understanding these calculations is crucial for designing efficient cooling systems for electronics packages to prevent overheating and ensure optimal performance.