Tmax— °C
Tavg— °C
Tmin— °C
hotspot at—
Φ Thermo — instant PCB thermal estimator.
Place components, set power, and read the steady-state heatmap in a few milliseconds. Honest depth-averaged FDM on a 64×64 grid with convection on both faces. This is an estimator, not a sign-off tool — for that, take it to TRM.
keff in-plane— W/m·K
copper volume— %
total power— W
grid · solve—
Component temperatures
| name | T (°C) | P (W) |
|---|
—
What this is — and what it isn’t.
What it solves
The depth-averaged 2D steady-state heat equation on the PCB plane, with convection on top + bottom faces as a distributed sink. Discretized as finite differences on a 64×64 grid, solved by SOR (ω≈1.85) to ~0.001 °C.
In-plane effective conductivity is computed from your layer count, copper weight and average copper fill (a parallel-path approximation through the layered material).
What it ignores
- Component package thermal resistance (RθJC & RθJA — junction-to-case & junction-to-air).
- Localized copper pours (treats fill as uniform per layer).
- Convection coupling to a chassis / enclosure (use CFD for that).
- Transient / cycling behavior — steady-state only.
- Thermo-mechanical / via thermal paths (it does NOT model individual vias).
When to use it
Use Φ Thermo to scope a thermal problem in seconds — “is my hot component above 100 °C, or above 200 °C?” — and to compare layout choices side-by-side without leaving the browser.
When the answer matters for a real fab decision, take the same board into TRM — that solves the coupled electrical-thermal network with real component models, vias, and IR-correlated boundary conditions. Φ Thermo is the funnel; TRM is the authority.
For sign-off, take it to TRM.
14-day trial, sample boards. Or have us run it under PhySignoff.