Following is about the function of SMT Nozzle.
With the miniaturization of electronic components, 0.4*0.2mm chip components have appeared in SMT chip processing, and the nozzle contacts with components at high speed, and its wear is very serious, so the material and structure of SMT nozzle are paid more and more attention.
The actual mounting tool for picking and placing on the mounting head is the SMT nozzle, which is the heart of the head. When the SMT nozzle is picking, a certain vacuum degree must be reached before the SMT processing can judge whether the components are normal. When the components are on the side or the "tape" of the components cannot be picked up, the mounter will send out an alarm signal.
When the SMT nozzle picks up the components and pastes them on the SMT circuit board, two methods are usually adopted for placement. One is based on the height of the components, that is, input the thickness of the components first. When the SMT nozzle drops to this height, the SMT chip processing vacuum is released and the components are pasted on the pad. Sometimes, due to the thickness error of the components, it will pick or place too early or too late, and in serious cases, it will cause the defect of component displacement or flyer. the other is more advanced, according to the reaction force generated at the moment of contact between components and PCB, the nozzle can realize soft landing under the action of pressure sensor, which is also known as the soft landing of z-axis. Therefore, the placement is easy, and the displacement and flyer defects are not easy to occur.
In the early stage, the alloy material was used, and then the carbon fiber wear-resistant plastic material was used. The more advanced SMT nozzle was made of ceramic material and diamond, which made the nozzle more durable. The structure of SMT nozzle has also been improved, especially in the chip of 0402 and 0603 element, in order to ensure the reliability of suction, two holes are opened on the SMT nozzle to ensure the balance of suction. In addition, it is considered that not only the size of the element itself is decreasing, but also the gap between the element and the surrounding element is also decreasing. Therefore, the improved SMT nozzle can be easily mounted even if the gap between the elements is 0.15 mm.