The flying probe test is the latest solution to some of the major problems in electrical testing. It replaces the needle bed with a probe and uses multiple motor-driven, fast-moving electrical probes to make contact with the device's pins for electrical measurements.
Introduction
Originally designed for bare boards, this instrument also requires complex software and programs to support it; it is now possible to effectively perform analog online testing. The advent of flying probe testing has changed the testing methods for low yield and
quick-turn assembly products. Tests that previously took weeks to develop are now available in a few hours, dramatically reducing product design cycles and time to market.
Structural features
The flying probe tester is an improvement on the traditional needle bed online tester. It can replace the needle bed with a probe. The XY mechanism is equipped with 8 test probes for 4 heads that can be moved at high speed respectively. The minimum test gap is 0.2mm. The UUT (unit under test) is transported into the test machine through a belt or other UUT transfer system, and then the probe of the fixed test machine contacts the test pad and the via to test a single component of the UUT. The test probes are connected to the driver (signal generator, power supply, etc.) and sensors (digital multimeter, frequency counter, etc.) through a multiplexing system to test the components on the UUT. When a component is being tested, the other components on the UUT are electrically shielded by the probe to prevent reading interference.
The flying probe tester can check for shorts, opens and component values. A camera was also used on the flying probe test to help find missing components. Use a camera to check the shape of a component in a clear direction, such as a polar capacitor. With probe positioning accuracy and repeatability in the 5-15 micron range, the flying probe tester can accurately detect the UUT.
The flying probe test is an invaluable production resource because of its ability to closely contact shielded UUTs and the ability to bring new products to time-to-market. Also, because there is no need for experienced test development engineers, the system also saves manpower and saves time.
