Circuit fault diagnosis methods

The earliest circuit fault diagnosis methods mainly relied on simple tools for testing and diagnosis, which greatly relied on the theoretical knowledge and experience of experts or technicians. Among these testing methods, the four most commonly used are virtual testing, functional testing, structural testing, and defect and fault testing. Virtual testing does not require the detection of actual chips, but only tests simulated chips, which is suitable for conducting before chip manufacturing. It can detect faults in chip design in a timely manner, but it does not consider noise or differences in the actual manufacturing and operation of the chip. Functional testing determines whether a chip has a malfunction based on whether it can perform the expected function during testing. This method is easy to implement but cannot detect faults with non functional effects. Structural testing is an improvement on built-in testing, which combines scanning technology and is often used for fault detection of produced chips. Defect and fault testing is based on the actual production of completed chips, and detects whether there are faults by inspecting the production process quality of the chips. Defect and fault testing requires a high level of knowledge and experience from professional technical personnel. Chip manufacturers usually combine these four testing techniques to ensure the reliability and safety of the entire process from design to production and application of integrated circuit chips. However, for increasingly complex circuit systems, these early methods have become increasingly inadequate. Through continuous improvement and innovation, many new ideas and methods have emerged one after another.