Definition

In-Circuit Test (ICT) uses a custom fixture with spring-loaded probes (bed-of-nails) that contact test points on the PCB to verify component presence, orientation, and values. ICT can detect missing components, wrong values, shorts, opens, and some functional defects. For PCB designers, ICT requires dedicated test points - typically 0.9-1.0mm pads on a 2.54mm grid, accessible from one side of the board. Provide at least one test point per net for full coverage. ICT fixtures are expensive ($2,000-$15,000) so ICT suits medium-to-high volume production. For prototypes and low volume, flying probe test achieves similar coverage without fixtures.