The PCBA circuit board involves many circuits and components, and testing is extremely important, which is related to the product’s pass through rate and delivery quality. The current five mainstream testing methods for circuit boards are:
1. Manual visual testing
Manual visual testing is one of the most widely used online testing methods, which confirms the placement of components on a PCB through human vision and comparison. But as production increases and circuit boards and components shrink, this method becomes increasingly unsuitable. Its main advantages are low pre cost and no testing fixtures; Meanwhile, high long-term costs, discontinuous defect detection, difficulty in data collection, lack of electrical testing, and visual limitations are also the main drawbacks of this method.
2. Automated Optical Inspection (AOI)
This testing method, also known as automatic visual testing, is usually used before and after reflow, and is a relatively new method for confirming manufacturing defects. It has a good inspection effect on the polarity of components and the presence of components. It is a non electrical, fixture free online technology. Its main advantages are easy to follow diagnosis, easy program development, and no fixture; The main disadvantage is poor identification of short circuits and not electrical testing.
3. Functional Test
Functional testing is the earliest principle of automated testing, which is a basic testing method for specific PCBs or units, and can be completed using various testing equipment. There are two main types of functional testing: Final Product Test and Hot Mock up.
4. Flying Probe Tester
Flying needle testing machine, also known as probe testing machine, is a commonly used testing method. Due to advances in mechanical accuracy, speed, and reliability, it has been widely welcomed in the past few years. In addition, the current requirement for testing systems with fast conversion and fixture free capabilities required for Prototype and low production manufacturing makes flying needle testing the best choice. The main advantages of the flying needle testing machine are that it is the fastest time to market tool, automatically generates tests, has no fixture costs, good diagnosis, and is easy to program.
5. Manufacturing Defect Analyzer (MDA)
MDA is a good tool for diagnosing manufacturing defects only in high-yield/low mix environments. The main advantages of this testing method are low initial cost, high output, easy to follow diagnosis, and fast and complete short-circuit and open circuit testing; The main disadvantage is that functional testing cannot be conducted, and there is usually no indication of test coverage. Fixtures must be used, and testing costs are high
