The solver
The same depth-averaged 2D steady-state FDM solver as Φ Thermo — G·ΣTneighbors + C·(Tamb−T) + P = 0 on a 48×32 grid. Solves in ~30 ms per click.
Φ Thermal — the PCB cooling puzzle.
Click to place thermal vias (V) and copper pours (P) on the board. The heatmap updates in real time using the same 2D FDM solver as Φ Thermo. Keep every component below its Tj_max limit to pass the level. Budget is tight — place wisely.
Thermal via
Copper pour
Component OK
Component over limit
How the physics works
What placements do
Thermal vias increase the board’s effective in-plane conductivity (keff) and the convection coefficient from both faces — they conduct heat down to plane layers and provide a low-impedance thermal path. Copper pours spread heat laterally before it reaches the vias.
What this isn’t
A simplified model for gameplay. Real thermal sign-off accounts for via fill material, RθJC, and package-level effects. Use TRM for production sign-off; use Φ Thermal to develop your thermal intuition.
For real boards, use TRM.
14-day trial, sample boards, Altium-integrated. Or have us run it under PhySignoff.