Comparison of detection techniques in PCBA processing(part 1)

Comparison of detection techniques in SMT PCBA processing shared by printed circuit board manufacturer.

At present, in the field of SMT electronic assembly, a wide range of detection technologies are used, including manual eye inspection, online test automatic optical detection, automatic X-ray detection and functional testing. These detection methods have their own advantages and disadvantages.

(1) artificial eye inspection is a method of visual inspection. The test van co., LTD., to test components packing, polarity, model is right and wrong, bridge LianJi part of virtual welding, mountain in artificial visual inspection is easy affected by man's subjective factors, therefore, has the very high instability in the treatment of the 0603, 0402, and fine pitch chip manual visual inspection more difficult, especially when is used in great quantities in the BGA component, check the quality of the welding, manual visual inspection and powerless.

Blue solder mask 1.6mm 2 layers lead free HASL FR-4 PCB

(2) flying needle test is a kind of machine inspection method, which USES two probes to electrify components to detect defects such as failure and poor performance of components. This test method is relatively close to the PCB with inserted PCB and PCB with low density installed by components with sizes above 0805. However, the miniaturization of components and high density of products make the deficiency of this test method obvious. For 0402 class components, due to the small area of solder joint, the probe cannot be connected accurately, especially for high-density consumer electronics products, the probe cannot touch the solder joint. In addition, its PCB with parallel capacitor, resistor and other electrical connections cannot be measured accurately. Therefore, with the high density of products and the miniaturization of components, the use of flying needle test in actual testing is also becoming less and less.