Flying Probe Test

What Is Flying Probe Testing?

Flying probe testing is an electrical test method for PCBs and assembled boards where motorized probes move to different test point locations on the board surface to measure connectivity, isolation, and component values. Unlike bed-of-nails in-circuit testing (ICT), which requires a custom-built test fixture with fixed probe positions, flying probe testers use robotic arms that can reach any accessible point on the board. This flexibility makes flying probe testing ideal for prototype quantities, low-volume production, and designs with frequent revisions where the cost of building a dedicated ICT fixture is not justified.

Flying probe testers can verify net connectivity (confirming that all points on a net are electrically connected), isolation (confirming that nets that should not be connected are properly isolated), and passive component values (measuring resistance and capacitance in-circuit). The primary tradeoff compared to ICT is speed: flying probe testing is significantly slower because probes must move sequentially between test points rather than making simultaneous contact. For high-volume production, ICT remains the preferred method; flying probe is most cost-effective for volumes below a few thousand boards per batch.

Test Strategy Considerations in Layout

The choice between flying probe and ICT testing influences PCB layout requirements. Flying probe testers can access smaller test points and tighter locations than bed-of-nails fixtures, relaxing some layout constraints on test point size and spacing. However, both methods benefit from clearly defined test access points on the board. AI-powered layout tools can optimize test point placement for the target test strategy, ensuring adequate access for flying probe contact while maintaining the board density and electrical performance that the design requires.

Other glossary terms

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
There are no available glossary items matching the current filters.
Reset