Measuring PCB Temperature

Sixty to sixty-five percent of the heat generated on a printed-circuit board (PCB) is transferred to the temperature sensor die via its pins. The GND pin is connected to the substrate, and therefore has the least thermal resistance between temperature sensor and heat source.

Measuring PCB Temperature Figure 1
Figure 1. Correct Layout for Measuring PCB Temperature

Tips for efficient PCB temperature measurement

  • Use a common ground plane between the temperature sensor and the heat source
  • Connect the GND pins of all temperature sensors to ground plane of the heat source
  • Keep temperature sensor and heat source as close to each other as possible on PCB

By following these tips, the temperature sensor will accurately track the temperature of the PCB and subsequently the main heat source, as shown in the figure 2.

Measuring PCB Temperature Figure 2
Figure 2. Temperature Sensor Accurately Tracks the Temperature of the Heat Source


Donal McNamara