Since the arrival of the personal computer, the electronics market has been subject to a constant, overarching pressure from end-users to miniaturise components while maximising performance. However, meeting these twin demands presents a challenge: how does one accurately test tiny components for both product faults and overall quality control when most of these electronics are too small for conventional diagnostic tools?
High-accuracy thermal imaging cameras may provide the answer.
It is critical for companies that design high-performance printed circuit boards (PCBs) and other electronics to understand the thermal properties of their products. Without proper testing, reliability issues may sneak past typical quality assurance inspections, only to be discovered in a mass-production phase or even by users later on. The thermal properties of all the device’s components tell the story of how well the device is functioning and can help highlight potential weaknesses. When a device does malfunction and requires maintenance, the presence of excess heat can help engineers pinpoint the source of a problem. Then later, consistent temperatures across a device can help engineers verify the quality of a repair.
Because overheating components commonly trigger malfunctions, it is important to appropriately identify high or low thermal activity down to the component level. A comprehensive heat map can offer valuable insight into how a device is working and how to make it more efficient—even if there aren’t any outright signs of failure. Precision and scope, then, emerge as primary attributes of an ideal testing system.
Traditionally, thermocouples are used to measure the heat of a component but they are not an ideal solution for small electronics. These devices only measure a single point at a time and are often much larger than the components they’re meant to measure—meaning they can act as a heat sink, drawing away some of the heat.
In some cases, spot pyrometers might offer some value. These tools do not need to make contact with the parts being tested and therefore do not affect measurement accuracy by acting as a heat sink. But like the thermocouple, these instruments measure heat only at a single point on an object and, therefore offer an incomplete picture of a target’s thermal properties. Plus, checking each component one-by-one with a spot pyrometer would be a slow, arduous, and hard-to-repeat process.
The Thermal Imaging Solution
Faced with the need to test electronics quickly and accurately, many producers are turning to thermal imaging cameras for product development and quality control. Thermal imaging cameras work by detecting infrared radiation and translating it into a temperature reading that can be viewed on a monitor. A single camera can produce thousands of non-contact temperature readings at the same time, one for each pixel in every image. By converting accurate temperature measurement into visual information, users can visually see faults (hot spots and potential points of failure) quickly and accurately, including faults that might otherwise be missed.
Because they can scan an entire section of components at once, they are well-suited to inspecting heat signatures on PCBs and other small electronic devices. The engineer or technician can start with an overall view of the device to see where current is flowing and check for any signs of overheating. From there, the technician can use the camera to zero in on a specific area and take accurate readings on the hot spot. By quickly narrowing the search to a target area, the thermal camera reduces the time it takes to troubleshoot a problem.
Selecting the Proper Technology for Electronic Repair Applications
While there is a wide range of thermal imaging cameras available, product development labs have specific need to address. There is often a premium on space in the lab; the camera needs to be easy to move from one benchtop to another; and lighter-weights are preferred. Some thermal cameras are bulky instruments with large germanium lenses, making them hard to move and even more difficult to hold steady. Engineers may consider a lighter, handheld camera, but these often do not come with close-up lenses or the ability to resolve tiny components.
The ideal solution is a thermal imaging camera designed specifically for benchtop use. Such a camera needs to be compact, hands-free, and cost-effective. In addition, a thermal imager for this application should be able to resolve small parts such as integrated circuits, resistors, capacitors, and other complex components from a short but adjustable distance.