1. Manual visual inspection
Visual inspection can be performed at each step of the PCBA process. Manual visual inspection of PCBA assembly is the most primitive method in PCBA quality inspection. It only USES eyes and magnifying glass to check the welding of PCBA board's circuit and electronic components, such as welding mode, whether the welding spot is brided, whether there is insufficient welding and whether there is incomplete welding. Magnifying glass is the base tool for visual inspection, and metal pins can be used to check for welding imperfections on IC leads.
2. Online tester (ICT)
On-line tester is widely used in PCBA processing industry for its excellent test and inspection performance. ICT can almost identify welding and component problems in PCBA. It has high speed and high stability. The electrical probe tests the filled printed circuit board (PCB) and checks for short circuit, open circuit, resistance, capacitance, and other basic quantities to indicate whether the component is manufactured correctly.
3. Automatic Optical Detection (AOI)
Automatic optical detection is a non - contact testing method. Automatic optical detection plays an important role in inspection. Automatic optical detection is an automatic visual inspection during the manufacture of printed circuit boards, in which the camera automatically scans the PCBA board under test for catastrophic failures (such as missing components) and quality defects (such as rounded dimensions or shapes or component deflections).
4. Automatic optical detection (AXI)
With the widespread use of BGA and CSP, typical detection methods such as ICT cannot check the embedded solder joints of the component. AXI can test misalignment, missing balls and solder deposits. AXI USES X-rays to travel through solid objects to capture their images. It can be divided into two types: 2D and 3D.
5. Functional circuit testing
The functional circuit test is the last test before the PCBA product is launched. Unlike other tests, such as AOI, AXI, and ICT, FCT aims to make the UUT (unit under test) work in a simulated environment and use output data to check its actual performance.
6. Sample inspection
Prior to mass production and assembly, PCB manufacturers and assemblers usually conduct a first sample inspection to check that SMT equipment is properly prepared so that vacuum nozzles or alignment problems can be avoided during mass production, resulting in PCBA board production problems. This is referred to as a first piece inspection.
7. Flying needle tester
Flying needle probe is suitable for high complexity PCB inspection which requires expensive inspection cost. The design and inspection of flying needles can be completed in a day and the assembly cost is relatively low. It can check the open circuit, short circuit and direction of components mounted on a PCB. In addition, it does a good job of identifying component layout and alignment.
8. (Manufacturing Defect Analyzer, MDA)
The purpose of MDA is simply to visually test the board to reveal a manufacturing defect. Since most manufacturing defects are simple connectivity problems, MDA is limited to measurement continuity. Typically, the tester will be able to detect the presence of resistance, capacitance, and transistors. Protective diodes can also be used to detect integrated circuits to indicate whether components are properly placed.
