Parameter Settings
Component Type
Power Dissipation P
5.00 W
θjc (Junction–Case)
1.50 K/W
θcs (Case–Spreader)
0.50 K/W
θsa (Heatsink–Ambient)
5.00 K/W
Ambient Temperature Ta
25 °C
Thermal Via Count N
16
Board Thickness t
1.60 mm
Airflow Velocity v (forced)
0.0 m/s
0 = natural convection
—
Tj Junction Temperature [°C]
—
Tc Case Temperature [°C]
—
PCB Surface Temperature [°C]
—
ΔT = Tj − Ta [K]
—
θja Total [K/W]
—
Status (125 °C limit)
Thermal Resistance Network Theory
The thermal path of an electronic component from junction to ambient is treated as a series connection:
$$T_j = T_a + P \times \theta_{ja}$$ $$\theta_{ja} = \theta_{jc} + \theta_{cs} + \theta_{sa}$$Thermal via parallel resistance: $\theta_{via} = \dfrac{t}{N \cdot k_{Cu} \cdot \pi r^2}$ (r=0.15 mm, k=385 W/m·K)
Natural convection heatsink: $\theta_{sa} \approx \dfrac{1}{h_c \cdot A_s}$ (h_c ≈ 5–15 W/m²K)
Forced convection: $h_c \approx h_0 + c \cdot v^{0.6}$ (velocity power law)
CAE Integration: Use as input verification for PCB thermal analysis tools such as ANSYS Icepak / FloTHERM / SIMetrix. Electromigration lifetime is evaluated by the AMR method using Tj = 125 °C as the reference.