A flying probe test is a type of printed circuit board (PCB) or printed circuit assembly (PCA) test that uses a probe mounted on a mechanical arm. One major advantage to using a flying probe test instead of a bed-of-nails test is that the probe can go just about anywhere. Aside from testing the current, the probe also ensures all the parts are there and none have fallen off. These units normally can integrate with computer-aided design (CAD) programs and are made to work with a limited number of parts, so it typically is easy to program them.
The flying probe test is used mostly in manufacturing plants that create PCBs and PCAs, though it can be used for other electronics. This test consists of a probe that flies around the unit and uses a needle to test out the various parts on the unit. By doing this, it enables the manufacturers to ensure that all the units are working before they are shipped out.
Competing with the flying probe test as a major testing standard is the bed-of-nails test. This uses a bed of electronic needles — like the one needle on the probe — to push a current through the unit to ensure it works. While the bed method can test a large area at once, it is limited to flat units, because the bed cannot maneuver angles or curves. A probe is able to move around, because it is on an arm, so it can easily check every area of the unit. To speed workflow, two or three probes usually are used at once.
While ensuring the unit can properly conduct electricity is important, there is another matter that is equally important: the parts. Some parts may fall off during production, because they are improperly affixed or the shifting and moving from production shook them off. By using a camera and other testing equipment, the flying probe test also can check for proper production.
The flying probe test usually is used on common PCBs and PCAs, and this information will be stored in the probe’s software. This means programming the probe to test certain areas typically is easy and little coding is needed. If the unit is completely unique, then most probes can integrate with CAD programs and the user can tell the probe what areas to check from there.