What is a Flying Probe Tester?
A flying probe tester is a robotic machine used to check the electrical performance of a PCB. It can be used to check the electrical performance of an assembled or bare printed circuit board. As the name suggests, it uses a ‘flying probe’ i.e. probe connected to a robotic arm to check electrical performance at various points on the board. It can be used to check open circuits, shorts, capacitance, inductance, impedance, tolerances and many other parameters of traces and component pins on the PCB. Sometimes, a high definition camera is also installed with the flying probe system to check the component orientation, polarity, and misalignment.
If the flying probe tester finds any defects, then the board will be sent to rework to fix these defects. A flying probe machine usually consists of multiple robotic arms each with a probe (sharp needle). The number of flying probes usually varies from 1 to 20 (Can be higher as well). Flying probe testers are mainly used to test low volumes or prototype boards because the testing-cost and testing-time per board is high as compared to ICT (In-circuit testing). ICT is another electrical performance testing method.
How does a Flying Probe Tester work?
The test probes (sharp needles) of a double-side flying probe tester are "flying" both the top and bottom side of the PCB (placed on the stand). The flying probes can have the ability to access any point on the test board. As per the program instruction, the flying testing probes simply touch the test points of the board and take measurements and then probes move away from those points and take measurements on other test points. These sharp needles do not damage the board while testing. The electrical performance measured data is processed and compared with the original reference board data by the computer, and the board status pass/fail (with the type of defect details, if any) will be displayed on the screen.
Key Specifications of Flying Probe Testers:
Number of arms: It represents the number of arms/probes the tester has.
Number of test steps: It indicates the number of tests that the machine is doing on a PCB. Typically the number of tests increases when the complexity of the board increases.
Resistance: It represents the resistance range that can be measured in ohms by the machine.
Capacitance: It represents the capacitance range that can be measured in Farads by the machine.
Inductance: It represents the inductance range that can be measured in Henry by the machine.
System Type: Single Sided or double sided. Single sided machines test on only one side of the PCB, whereas double sided machines test on both sides of the PCB.
Probing precision: It represents the accuracy of movement in X and Y direction and is represented in ± X μm for each arm. For example, some machines have a probing precision ±100 μm for each arm (X and Y direction).
Positioning repeatability: It is a measure of the exact Positioning capability of the machine for conducting tests when a repeatable operation. It is measured in ± X μm. For example, the Positioning repeatability of a machine can have ± 50 μm.
Max board size: It is the maximum size of the PCB that the tester can handle.
PCB thickness: It is the PCB thickness that can be handled by the tester.
Camera: Some testers have cameras attached to the robotic arms which can be used for board, trace or pin inspection.
Short: It represents the short circuit resistance’s range that can be measured by the machine.
Open: It represents the open-circuit resistance’s range that can be measured by the machine. The open-circuit resistance range usually varies between several ohms to Mega-ohms.
DC voltage measurement: It represents the DC voltage measurement range.
PCB Directory has listed Flying Probe Testers from the leading manufacturers in the industry and made it easy for users to find these machines based on their requirement. Users can specify the type of equipment, number of probes and other parameters to find a tester that meets their requirement. They can then view tester specifications, download the spec sheet and get a quote. Quotes requested are routed to manufacturer of the flying probe tester.
