Hello, I will try and provide as much detail to the problem as I can with the hope someone can help me solve this. We are currently working on a wireless project that contains high electrical currents, because of this the box the electronics are enclosed in experience quite a temperature rise. The basic concept is I have a PCB that is housed inside a copper box, the copper box has 3 layers, outer layer is copper, middle layer is plastic, inner layer is copper. I want to calculate the temperature inside the copper box and outside the copper box. Here are some details that we know: The PCB dimensions are: 3mm H x 37mm W x 159mm L The outer copper box outer dimensions are: 17.9mm H x 41.9mm W x 163.9mm L; wall thickness is 0.2 mm The plastic box outer dimensions are: 17.5mm H x 41.5mm W x 163.5mm L; wall thickness is 3 mm The inner copper box outer dimensions are: 15mm H x 39mm W x 161mm L; wall thickness is 0.2 mm PCB Thermal conductivity: .25 W/m*K Copper thermal conductivity: 400 W/m*K Plastic thermal conductivity: .146 W/m*K bPlastic emissivity: 0.9 Copper wall emissivity: 0.2 Ambient temperature: 20 C max Temp: 41 C Power: 7.6 W Current: .48 amps Resistance: 33 ohms i have attached some pictures to help. Please let me know if you have any questions, I have been stuck on this problem.