Thermal Management Calculators
6 free calculators with formulas and worked examples.
Heatsink selection, junction temperature, PCB trace temperature rise, thermal via arrays, and thermal resistance network calculators for component and board-level cooling.
Heatsink
Calculate required heatsink thermal resistance (θ_SA) and junction temperature for MOSFETs, IGBTs, and power ICs. Verify thermal design feasibility. Free results.
Trace Temp
Calculate PCB copper trace temperature rise under load current using IPC-2152 and IPC-2221 standards. Enter trace width, thickness, and current to get ΔT above ambient. Essential for thermal PCB design and reliability engineering. Free, instant results.
Thermal Resistance Network
Calculate junction, case, and heatsink temperatures through a series thermal resistance network (θJC + θCS + θSA) for component thermal management
Junction Temperature
Calculate semiconductor junction temperature from power dissipation and thermal resistance chain (θJC + θCS + θSA). Essential for transistor, MOSFET, and IC thermal design.
Heatsink Selection
Calculate the required heatsink thermal resistance (θSA) to keep a device junction below its maximum temperature. Use this to select an appropriate heatsink.
Thermal Via Array
Calculate thermal resistance of a PCB thermal via array for heat spreading from SMD packages to inner copper planes or heatsinks.
About Thermal Management Calculators
Thermal management determines whether a component reaches its maximum junction temperature under worst-case operating conditions. Semiconductor reliability degrades exponentially with temperature — a 10°C increase roughly halves MTBF for many devices — making thermal design a reliability discipline, not just a comfort margin.
The thermal resistance network models heat flow by analogy with Ohm's law: power (current) flows through a series of resistances from junction to ambient. Junction-to-case resistance (θ_jc) is specified by the IC manufacturer; case-to-heatsink (θ_cs) depends on interface material and mounting pressure; heatsink-to-ambient (θ_sa) is the heatsink datasheet value at the operating airflow. Total junction temperature: T_j = T_ambient + P × (θ_jc + θ_cs + θ_sa).
Heatsink selection requires knowing the power dissipated, ambient temperature, and allowable junction temperature. For forced-air cooling, thermal resistance drops dramatically with airflow velocity; natural convection heatsinks must be sized conservatively. Thermal interface materials (TIMs) — thermal paste, pads, or phase-change materials — fill microscopic air gaps at the contact surfaces, reducing θ_cs from ~1°C/W (dry contact) to 0.1-0.3°C/W.
PCB trace temperature rise under current load follows IPC-2152 models that distinguish between internal and external layers. Via thermal resistance arrays provide low-resistance thermal paths through the PCB to heat spreader planes or bottom-side heatsinks — common in LED drivers and power modules. The thermal via calculator determines the number and arrangement of vias needed to meet a temperature rise target.