Sipotek is a professional china automated optical inspection machine manufacturers located in shenzhen city,major products including visual inspection machine and automated optical inspection (AOI) machine.
Today we will talking about image capture and analysis with AOI systems from automated optical inspection manufacturer.
The image capture system is a key elements of an automated optical inspection system. It captures an image of the PCB assembly printed circuit board, which is then analyzed via a processing software within the AOI system. There are many variants of the image capture system that depend on the exact application and cost/complexity of the AOI system.
Imaging systems may include a single camera or there could be more than one to offer better images and the possibility of a 3D capability. The cameras should also be able to move under the control of software. This will allow them to move to the ideal position for a given set of PCBs.
In addition, the camera type affects performance. Speed versus accuracy is a balance that must be achieved and will have an impact the type of camera used:
Video Streaming: A type of camera used for automated optical inspection, AOI, transmits video from which full frames are taken. The captured frame allows to generate a still image in which the signal is processed. This approach is not as accurate as other static imaging systems, but has the advantage of a very high speed.
Fixed Image Camera System: It is usually placed relatively close to the target PCB and, as a result, needs a sound lighting system. You may also need to be able to move the camera via the control of software.
When analyzing the image of a board, the AOI machine seeks for a variety of specific characteristics: component size, component location, fiducial board, label patterns (e.g. bar codes), reflectivity and background color etc. As an important element of your task, the AOI system also inspects the welded joints to make sure they indicate that the joints are satisfactory.
During the analyses boards, the AOI system must take into consideration many variations between good boards. Not only does the components differ widely in size between lots, but also reflectivity and color. Often there are also differences in the silk screen, where the thickness of the ink and the type of the color may change slightly.
An Automated optical inspection manufacturer employs a number of methods to analyze whether a board is satisfactory or has a defect:
Template Models: When using this form of process, the automated optical inspection system AOI compares the image obtained with the image of a “gold plate”.
Matching Patterns: Using these techniques, the AOI system stores information about good and bad PCB sets, combining the image obtained with them.
Statistical pattern matching: This approach is very similar to the previous one, except that it makes use of statistical method to solve problems. By storing the results of multiple cards and various types of failures, you can accommodate small acceptable deviations without markup errors.
To build the database of what the board should be, the known status tables and the PCB design information are used as described below.
As the technology improved, AOI systems were able to predict defects with great accuracy and have a small number of flawless scenarios encountered. As such, AOI systems form a very useful element in a sophisticated manufacturing environment.
About Shenzhen Sipotek Technology Co., Ltd
Started in 2002, Sipotek Technology is located in Shenzhen in China. The company designs and manufactures visual inspection systems with its avant-garde R&D department and a great experience in artificial vision technologies. The Sipotek Technology staff supports customers 360 degrees automatd optical inspection(AOI), from listening to their requests to the development of ambitious machines for quality control.
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Contact Person: James Yuan
Company: Shenzhen Sipotek Technology Co., Ltd
Email: [email protected]