Basic electrical test equipment is used Tester ( ICT ) , the traditional use of online testing instrument with a special needle bed has been good on the circuit board components welded contact with hundreds of millivolt voltage and 10 mA separation within the current of isolation tests to accurately measure the loaded resistors, inductors, capacitors, diodes, transistors, SCR, FET, integrated block and other general and specific components of the missing equipment, wrong equipment, the parameter values deviation solder joints with welding, short circuit, open circuit board failure, and failure is short-circuit in which components or open to tell the user exactly which point. Needle Bed Tester is to test the speed advantage for civilian-type appliances in a single species maximum size of circuit board production testing, but the host cheaper. But with the increased density of circuit board assembly, in particular, fine pitch SMT assembly and new product development cycle is shorter and shorter, more and more varieties of circuit board, needle-bed-type circuit tester to overcome some difficult issues: test the production of needle-bed fixture, debug cycle is long, expensive; for some high-density SMT PCB test accuracy because the issue can not be tested.
Basic ICT recent years, with advanced technology to overcome the limitations of the technology improvements. For example, when integrated circuits became too big to not provide coverage for the equivalent circuit detection target, ASIC engineers developed a boundary-scan technology. Boundary Scan (boundaryscan) provides an industry standard way to identify where the probe does not allow the components to connect. Additional circuit design to IC inside, allowing components to a simple way to communicate with the surrounding elements to a format easy to check test results. Another non-vector technology (vectorleestechnique) AC (AC) signal applied through the needle bed to test components. A sensor board Kaozhu test surface to suppress the components, and component lead frame to form a capacitor, the signal coupling to the sensor board. Coupling signal that solder joints do not open. Board for large and complex test procedures for artificially generated much time and energy, but the auto-test program generated (ATPG, automated testprogramgeneration) software solves this problem occurs, the software is based on the CAD data and PCBA assembly of the components in the standard library board automatically design the required fixtures and test programs. While these technologies help reduce the formation time of a simple procedure, but the high number of nodes in the test program and have demonstrated or time-consuming and technically challenging.