Printed circuit boards (PCB) inspection by thermal imaging

Posted by gm77 30/04/2019 0 Comment(s) 1423 IR Cameras,

When designing and producing printed circuit boards (PCB), it is very difficult to discover some manufacturing defects or design imperfections using traditional optical inspection methods. When supplying voltage to any PCB, the electric current starts to flow through the PCB and it starts to heat up.

A PCB thermal field can be determined and visualized by thermal imaging using a thermal camera. Using the thermal field knowledge manufacturing defects can be discovered at the very beginning or at least in the early design stage. Thermal imaging can also be successfully used during series or prototype manufacturing.

Typical defects that can be discovered on a PCB are, for example: electric short circuits, incorrectly located components during mounting, insufficient tin during soldering etc. In the PCB design stage thermography can be used to visualize the excessive heating of certain components, improper layout or, for example, non-proportional recording of the code into a FPGA chip. All these specific problems can be resolved by the suitable use of a Workswell WIC thermal camera with the option of suitable lens.

Thermal imaging can play a high role when inspecting a high amount of mounted PCBs and to immediately discover possible problems in the other ways after its mounting. If, for example, a component is incorrectly mounted (there are cold joints), the components maybe significantly heated. In the first phase of traditional equipment testing it may seem that everything is OK but during longer operation the components may stop functioning because of high temperatures, and therefore the whole equipment may stop working. These and other problems can be discovered with a Workswell WIC thermal camera immediately after mounting and activating the PCB without having to test the function of the equipment. By comparing the thermal images of the functional PCB with the actually tested PCB, any deviation from the norm can be discovered without knowledge so testing is very simple.

The use of thermal imaging may be helpful when designing PCBs and shorten the PCB development time. If the layout design is incorrect a high current may flow through some parts of the PCB producing excessive heating and an unstable PCB or shorten its service life. Without a thermal camera, these possible problems cannot be easily discovered. Using a thermal camera, the overall allocation of generated heat through the components on the PCB can be ascertained and the allocation of coolers and other components can be modified for the best operation of the developed equipment.

The sensitivity of the Workswell WIC thermal camera can be used, for example, to ascertain which part of the greater chip is actually or excessively loaded. In general, it is best for the used components if they are loaded and heated proportionally. For example, when compiling the code for an FPGA, the routing in the chip may not be carried out optionally and a thermal camera can be used to discover such cases.

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