Release time:2019-12-12 Browse:1718
The working principle of AOI optical detector
General process of AOI test is the same, mainly by pattern recognition. That will be stored in AOI system of standard digital images and the actual detected image compared to achieve results. For example, when the AOI check a solder joint, based on the complete solder to establish a standard digital images, and comparing with measurement of images, are the AOI inspection results through depends on the standard image, the resolution and check the use of the program. AOI pattern recognition was used in the various algorithms, such as looking for black and white, color, composition, average, sum, difference, flat, Angle and so on. AOI light irradiation by two types of equipment: white and coloured light. The white light using gray level 256, color using red, green and blue light. Light to the surface of the solder/component, the light is reflected back into the lens. Generate 3 d and 2 d image to reflect the height of the solder/component and color difference. When people see and identify objects, according to the amount of light reflected. Most of the reflection is bright, reflection is dark. The principle of AOI automatic optical detector is the same as the artificial judgment. In terms of number of lens, AOI has a single lens and the lens. It's just a choice on the implementation of technical solutions. It's hard to say this method must be good, because a single lens can be obtained from the different aspects of multiple light sources good AOI. Test image. Especially for lead-free welding, surface are relatively rough, can produce different shapes of solder joints, easy to form bubbles, and parts of end is easy to stand up.
The logic of AOI report defects are divided into two types: the design specification (DRC) and motherboard (CAM).
The design specification
AOI judging according to you to set the parameters, and in violation of the parameters of the report is unfavorable.
This defect is mainly the minimum line width, the minimum distance, pinhole and copper slag.
The mainboard is
AOI will learn from the CAM data of main data and actual comparison, the scanned image is beyond the scope of tolerance to report defects. The main drawback of this type is open circuit, short circuit, welding plate and pinhole.
Design specification and the mainboard is organically unifies in together, so that only report you are trying to find faults, and to minimize the number of the wrong point.
The above content is to point to some online content, only used to explain the working principle of the aoi, for quality control, reduce misjudgment, improve the efficiency of production, improve product quality and provide guidance.