SMT AOI machine is the abbreviation for Automatic Optical Inspection Instrument, the main role is used to detect the quality of reflow oven, such as the common bad standing tablet, even bridge, tin beads, more tin, missing parts, etc. can be detected, generally often located in the back section of the entire SMT line, greatly improving the efficiency and correctness of detection and improve the straight-through rate.
The working principle of AOI machine
AOI is an optical detector, from the Chinese word literally we can know and optical related, common optical is the camera (lens), and one of the core components of AOI is the lens. When the placement machine is installed after a PCBA, the next workstation is AOI inspection, PCBA into the AOI workbench interface, the lens will scan the PCBA in turn, and then through the AOI visual algorithm to generate the visible image of the naked eye, if bad, it will report an error, and will prompt the cause of the bad, if OK will be directly PASS, flow to the next workstation.
How to determine whether it is OK or bad, the premise is that the data of the OK board will be stored in the algorithm database, when there is a difference with the database in the algorithm, then the error will be reported (in some cases, after visual inspection is OK, then this data needs to be stored in the database in time to avoid subsequent continued error reporting). If an error is reported and then found to be defective by manual visual inspection, engineering and technology should be notified in time for error analysis, process improvement and additional rework.
Why is there a pre-furnace AOI?
General AOI are in the furnace, furnace AOI is placed in front of the multi-functional bonder, because some PCBA is required to mount shielding cover, and shielding cover is under the placement of electronic components, and AOI is not able to see through the shielding cover to check the placement quality (wrong parts, missing parts, etc.), then you need to add an AOI in front of the multi-functional machine to check the placement of the bonder (general shielding cover is placed on the multi-functional bonder ).
Why is manual visual inspection still needed when there is AOI?
AOI can greatly improve the efficiency of detection, although AOI stores a large number of welding bad quality data, but the process of placement by a variety of factors, there will be a lot of causes of bad, so sometimes the welding quality is good, but also appear error, then you need manual visual inspection, so there is AOI, but also can not give up the arrangement of manual visual inspection of the post.
Why do you need 3D AOI when you have 2D AOI?
Usually many factories have 2D AOI, but with the rapid development of electronic products, more and more integrated ICs are widely used, and 2D AOI is not able to detect floating height, warping and other defects, so customers let processing factories add 3D AOI for quality and product reputation.
Post time: Mar-30-2023