Since the arrival of the personal computer, the electronics market has been subject to a constant, overarching pressure from end-users to miniaturize components while maximizing 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. 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 contact 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.
Thermal Imaging Solution
One thermal imaging system to consider is the FLIR ETS320 thermal camera, a non-contact thermal measurement system for electronic board and device evaluation and repair. It offers a high-sensitivity infrared camera and integrated stand for hands-free measurement of small electronics. A pole-mount allows for fast, easy setup and enables the camera to be easily moved from one bench to another.
Simplified features allow users to focus on their work rather than on camera controls. In addition to being able to detects temperature shifts down to 0.06°C, the FLIR ETS320 boasts a wide temperature range for quantifying heat generation and thermal dissipation, from 20°C to 250°C. It can measure tiny components down to 170 µm per pixel spot size. Such capabilities reduce test times by taking the guesswork out of thermal testing. With 76,800 points of non-contact temperature measurement and a true 45° field of view, the ETS320 can provide the critical data needed on product weaknesses to shorten product development time and improve overall design.
Faster, Easier, and More Affordable Thermal Diagnostic Testing
San Francisco-based Highland Technology designs and manufactures custom electronics for aerospace, defense, scientific, and industrial applications. Their PCBs include upwards of 1,200 extremely small components and must perform both reliably and at a high level. Because of the size of these parts, it is impossible to precisely measure thermal stress with thermocouples. Highland works around this limitation by utilizing a thermal imager. However, their initial imager had a large geranium lens and an unwieldy hand-held body.
Then, Highland purchased the stand-mounted FLIR ETS320, which allowed users to place PCBs under the camera for measurement without vibration from the operator. “The ETS320 is great because it’s mounted and has a convenient adjustable focus,” says Highland Technology Engineering Manager David Stanislowski, “and you can just set it up exactly where you need it, leaving your hands free to electrically probe or move the device around exactly as you need to.” The camera’s accuracy measured up to the requirements and remains integral to both engineering and reliability testing at Highland.
Thermal diagnostic testing is a critical part of the development and maintenance of PCBs and other small electronic products. Thermal imaging systems are a prime solution for this kind of testing but selecting the right kind of camera is key. Tools such as the FLIR ETS320, with its ease of use and hands-free measurement functionality, enable benchtop thermal measurements to be faster, easier, and much more affordable. A benchtop thermal imager of this caliber is a solid investment for any serious electronics design or repair operation.