Introduction to the suction nozzle of the surface mount Technology (SMT) machine

To achieve the functions above the suction nozzle of the surface mount technology (SMT) machine, when designing the suction nozzle, people usually design the surface of the suction nozzle in contact with the component as a centrally symmetrical shape. As for the background plane of the suction nozzle used as the background for taking photos, it is designed as a matte surface without any color mixing on the surface. Of course, this background is also usually designed in a single color, such as yellow and black.

The suction nozzle of the surface mount technology (SMT) machine is not only a key component for the machine to place and attach the components it has picked up, but also serves as the background for the camera of the optical vision system to take pictures. It mainly utilizes the adsorption effect of vacuum to pick up the components, and uses air blowing to place the components attached to the suction nozzle at the coordinate positions on the circuit board.

When the suction nozzle of the surface mount technology (SMT) machine picks up components, to achieve the desired situation, it is necessary to ensure that the center of the component, the center of the suction nozzle, and the spatial center of the obtained image should be coincident. In fact, the adjustment of the optical vision system is also to compensate for the deviation caused by this non-coincidence during actual operation.

Different mounting components require different suction nozzles for suction. Almost every suction nozzle comes with a reflective background. This is mainly to have a good background during image acquisition, so as to ensure that the target label information is accurately highlighted during image processing. When extracting images, the suction nozzle serves as the background, enhancing the contrast of the image of the component and making it clearer and more visible.

1. Wear of the suction nozzle, deformation, blockage or damage of the suction nozzle can cause insufficient air pressure, resulting in the inability to lift components. Therefore, it is necessary to regularly check the degree of wear of the suction nozzle and replace it if it is severe.
2. The influence of the feeder: Poor feeding of the feeder (damage to the feeder gear), the material belt hole not being stuck on the gear of the feeder, foreign objects under the feeder, wear of the clamping spring, deformation and rust damage of the pressure belt cover plate, spring and other operating mechanisms, etc., which can lead to component misalignment, lifting of the plate or failure to lift the device. Therefore, regular inspection and handling should be carried out. To avoid causing a large amount of waste of components.
3. Insufficient vacuum negative pressure: When the suction nozzle picks up the component, a certain negative pressure is generated at the suction nozzle, which adsorbs the component to the suction nozzle. Generally, the negative pressure detection method is used to determine whether the component picked up by the suction nozzle is abnormal. When the detection value of the negative pressure sensor is within a certain range, the machine considers the suction normal; otherwise, it considers the suction poor. When the components are being sucked in, the vacuum negative pressure should be above 53.33kPa so that there is sufficient vacuum to suck in the components. If the vacuum negative pressure is insufficient, it will not be able to provide enough suction force to pick up the components. During use, we should frequently check the vacuum negative pressure and regularly clean the suction nozzles. At the same time, we should also pay attention to the contamination of the vacuum filter core on each mounting head. Its function is to filter the air source reaching the suction nozzles. Those that are contaminated or blackened should be replaced to ensure the smooth flow of air.
4. The influence of suction height: The ideal suction height of the suction nozzle is to press down 0.05mm from the surface of the component when it is in contact with it. If the pressing depth is too large, it will cause the component to be pressed into the feeding trough and the material cannot be retrieved instead. If the suction of a certain component is not good, the suction height can be slightly adjusted upwards, for example, 0.05mm. In the actual work process, the author once encountered a situation where all the components on a certain material table had poor suction. The solution was to appropriately increase the material taking height of this material table in the system parameters.
5. Issues with the incoming material of the suction nozzle: Some manufacturers' surface mount component packaging has quality problems, such as large errors in the spacing of the tooth holes, excessive adhesion between the paper tape and the plastic film, and too small the size of the material trough, all of which may cause the components to be unable to be lifted.