Thermal Spreading and Contact Resistance

1Fundamental Principles of Thermal Spreading Resistance

Thermal spreading (or constriction) resistance results when heat is conducted away from a finite region into a larger region (spreading resistance) or from a larger region through a smaller region (constriction resistance). Spreading or constriction resistance can be determined by solving transient or steady‐state heat conduction in a solid region with appropriately applied boundary and initial conditions. When the contact areas result in imperfect contact at the microscopic level, we find an array of discrete points of contacts results. Heat transfer across the apparent contact region occurs through conduction at these discrete points of contact and across the gap if there is a gas ...