A&D Lab · Scientific Cooperation

Thermographic Diagnostics of Electronic Components

Applying thermal imaging to non-contact diagnostics of electronic equipment — development of a procedure for use in service conditions.

Dr. Eng. Przemysław Matkowski — Wrocław University of Science and Technology, W-12/Z-5

Project conducted from April 1, 2013 to September 30, 2013, in cooperation with A&D Serwis.

Objectives and Project Assumptions

A diagnostic procedure that is simple and quick enough to be carried out in a service environment.
Safe for both the operator and the equipment under test (non-contact measurement).
Operator equipped with a checklist and a reference thermogram.
Minimized costs — both for purchasing and for ongoing use of the equipment.

Test Setup and Measurement Parameters

A test setup was designed to ensure repeatable testing conditions. Reliable measurement depends on key factors such as surface emissivity, reflected temperature, humidity, ambient temperature, and camera-to-object distance.

Thermogram of a laptop with marked temperatures of the CPU, GPU, heatsink, and heat pipe — Baseline thermal profile of a fully functional device — a reference for further measurements (max. ~81 °C in the CPU/GPU area).

Board Thermal Map — Functional Blocks

The procedure involves identifying the functional blocks of the motherboard (main converters, N/S bridge, clock generation, chokes, sound card, memory modules, WiFi/Bluetooth) and comparing their thermal signature against a reference thermogram.

Motherboard map with labeled functional blocks overlaid on a reference thermogram — Functional-block map of the motherboard used as a comparison reference.

Result 1 — Reference vs. Faulty Unit Comparison

The key methodological finding: a differential temperature map (reference minus test object) clearly identifies the faulty functional blocks. In the case examined, the faults were:

Colder than reference

north bridge
additional choke
sound card

Warmer than reference

input converters
clock generation
south bridge

Comparison of a reference thermogram (44.8 °C) with a faulty device thermogram (47.5 °C) and a temperature difference map — Reference (max 44.8 °C) vs. test object (max 47.5 °C) with a difference map ranging from −13.9 °C to +14.5 °C — a clear fault signature.

Result 2 — Current Flow Inside a BGA Package

Thermal imaging made it possible to visualize current flow inside a BGA package and identify individual soldered connections beneath the component (BGA balls) without disassembly. Across a 5 s, 10 s, and 30 s sequence, the local temperature rise reached 57.6 °C.

Sequence of BGA thermograms showing the location of a hot spot after 5, 10, and 30 seconds from power-on — Current flow in BGA: 26.4 °C after 5 s, 36.5 °C after 10 s, 57.6 °C after 30 s — precise localization of the connection without disassembly.

Result 3 — Cracked Solder Joint

A cracked solder joint produces a characteristic local hot spot reaching up to 60.7 °C. This defect, which is not visible under optical microscopy or in conventional X-ray inspection, is unambiguous in thermal imaging.

Thermogram showing a local hot spot of 60.7 °C at the location of a cracked solder joint, compared with an X-ray image — 60.7 °C hot spot above a cracked solder joint, compared with microscopy and X-ray.

Comparison of the same defect under optical microscopy, infrared imaging, and X-ray inspection — The same defect: optical microscopy (crack visible), IR (thermal signature), X-ray (crack not visible) — thermal imaging fills the gaps left by both other methods.

Result 4 — Voids Impairing Heat Dissipation (LED)

For a high-power LED, a temperature difference was measured between an area with voids in the heat-dissipating layer (L101: max 30.6 °C) and a defect-free area (L102: max 29.8 °C). The procedure detects assembly defects that directly affect component lifespan.

LED thermogram with two measurement lines showing temperature differences between areas with and without voids — High-power LED — comparison of L101 (with voids, 30.6 °C max) and L102 (without voids, 29.8 °C max).

Results and Implementation

A test setup was designed to ensure repeatable measurement conditions.
A test procedure was developed for several demonstrator units.
The procedure was applied in the engineering thesis "Research on Heat Dissipation from High-Power Electronic Components."
The procedure's effectiveness was confirmed in studies carried out for two Wrocław-based electronics companies, including A&D Serwis.

Summary slide of the study results — test setup, comparative thermograms, A&D Serwis and Lediko logos — Project summary: test setup (W-12/Z-5 laboratory, Wrocław University of Science and Technology) and comparative reference/fault results. Implementation partners: A&D Serwis and Lediko.

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