Many printed circuit board assembly defects cannot be identified easily using conventional methods. For this reason we use thermographic cameras when inspecting these components in our luminaires.
A thermographic camera or infrared camera is a device that forms an image using infrared radiation, similar to a common camera that forms an image using visible light. Instead of the 450–750 nanometer range of the visible light camera, infrared cameras operate in wavelengths as long as 14,000 nanometers.
Circuit board infrared analysis
All objects emit electromagnetic energy in a broad spectrum of wavelengths and in an amount that is proportional to their temperature. As the temperature of an object increases, the amount of electromagnetic energy it emits increases.
The operation of circuit boards involves the flow of electrical current, which produces heat when passing through a circuit having resistance. Since thermal behavior is closely related to current flow, the temperature distribution on an operating package, component, or assembly can be a good, repeatable indication of its operational status. Therefore, infrared images of a circuit board can be analyzed to determine a board's operational status.