Test Point
What Is a Test Point?
A test point is a specifically designated location on a PCB that provides physical access to an electrical node for measurement, debugging, or automated testing. Test points typically take the form of exposed copper pads, vias, or dedicated test point components that allow probe contact from test equipment. They are essential for manufacturing test processes like in-circuit testing (ICT), where bed-of-nails fixtures make simultaneous contact with dozens or hundreds of test points to verify component placement, solder joint quality, and basic circuit functionality.
Test point placement involves balancing accessibility requirements against board space constraints. ICT fixtures require test points on a consistent grid pitch (typically 100 mils or 50 mils) with adequate clearance from neighboring components and board edges. Test points should provide access to critical nets including power rails, ground, clock signals, reset lines, and communication interfaces. The test strategy — which nodes need test points and what type of testing will be performed — should be defined early in the design process to ensure that layout accommodates the required access.
Integrating Test Access Into Automated Layout
Test point requirements are frequently an afterthought in manual PCB layout, often added late in the design cycle when board space has already been allocated. This leads to compromised test access, missed coverage, or test points placed in locations that are difficult for fixtures to reach. AI-powered layout tools can incorporate test point requirements during the generation process, reserving space and placing test access points as an integral part of the layout optimization. This ensures that testability is designed in from the start rather than squeezed in as a last-minute addition.






