How Flying Probe Testing Works for PCB Assembly | Sierra Circuits

Flying probe testers use test probes that fly. The test probes move from one test point to another to detect defects in the board. The flying probe tester can test for shorts, opens, and component values such as resistance, capacitance, and inductance. The flying probe tester does not require custom fixtures, hence, called as a fixtureless in-circuit test when used on an assembled PCB. This makes it highly cost-effective for prototypes and low to mid- volume production.

00:34 - To carry out flying probe testing, we start by creating a flying probe tester test program to test a circuit board assembly in the flying probe tester. The generated test program is loaded into the flying probe tester and the circuit board assembly, to be tested, is placed on a conveyor belt so that it can move inside the tester area where the probes are present. When you run the test program, the probes will contact the component pads, test pads, and the unmasked vias as per the pre-loaded test program. The tester will apply electrical test signals and power to the probe points and make measurements thereof. These measurements will be processed inside the tester to find if the circuit portion between the probes is delivering the expected results within the specified tolerances.

01:19 - This is how the flying probe tester detects the defective units. The flying probe tester hardware includes signal generators, DC and AC power supplies, and various sensors. These provide signals required to excite the PCB nodes and to make measurements on the component nodes and interconnections on the PCB assembly. The hardware also includes a camera to inspect component polarity automatically. The flying probe tester is a reliable and cost-effective method to test the PCB assembly as comprehensively as possible given the accessibility constraints of a board design. .