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A different look at your PCB – Infrared

iMX6 Rex Infra-red comparision image
Here are some pictures of the same PCB, but running different software applications:
  • Notice the CPU temperature difference when nothing is running (49.9°C) and when a test is running (76.4) – compare the first and third picture.
  • Have a look at the picture in the middle. Memories become more visible when running a memory test.
  • See the huge difference in Ethernet temperature when Ethernet cable is connected (the middle picture, bottom right corner) and disconnected.
  • It’s interesting to see, how the whole PCB will warm up from a few hot components – the module PCB is much warmer than the Baseboard PCB (in background).
Picture: Uboot only (Ethernet unplugged).
01 uboot without eth module
Picture: Memory test (Ethernet connected)
03 stresstest mem module
Picture: CPU test + Memory test (Ethernet unplugged)
05 stresstest cpu+mem eth unplugged module

If you use a hot air gun, how the heat will spread on PCB?

This was also an interesting experiment, we used a hot air gun (you can see it on the right picture) to heat up a small PCB. Notice, how the middle GND exposed pad is much colder then the area without copper (note: the result may be affected by the shiny surface of golden areas).
SPS bottom gun rear1 180°C comparision