Thermal management apparatus and method for a circuit substrate

An electronic device comprising:

• a housing having an upper panel and a lower panel being spaced apart to define a gap, the lower panel at least partially defining a mounting surface;
• a motherboard coupled to the mounting surface;
• a circuit substrate assembly mounted to the motherboard, the circuit substrate assembly comprising:
• a circuit substrate having a first side including at least one heat generating component and a second side;
• a first thermally conductive layer thermally coupled to the first side including at least one heat generating component of the first side and thermally coupled to the second side;
• a second thermally conductive layer thermally coupled to the first thermally conductive layer on each side of the circuit substrate;
• and
• wherein the circuit substrate is supported on the mounting surface by the second thermally conductive layer being attached to the mounting surface;
• and
• wherein the circuit substrate assembly is spaced from the upper panel to define an air gap between the circuit substrate assembly and the upper panel.