The reasons for component displacement in SMT processing are complex, including vibration, temperature changes, operational errors, material quality, welding issues, and other factors. To improve product quality, it is necessary to improve the precision of SMT, train operators, control material quality, optimize PCB design, and other aspects. The following is a deep analysis of the reasons for component displacement in SMT processing:
1、 Displacement caused by vibration or vibration
Vibration during processing: The vibration generated by the SMT machine during operation, or the vibration generated by other mechanical equipment in the factory environment during operation, can cause slight displacement of components during the SMT process.
Vibration during transportation and storage: Even if the components are correctly positioned after SMT processing, they may still experience displacement if they are subjected to vibration during subsequent transportation or storage.
2、 Shift caused by temperature changes
Thermal expansion and contraction effect: When components and PCB boards undergo temperature changes, the thermal expansion and contraction properties of the materials may cause changes in the position of the components relative to the PCB board. Especially during the rapid cooling process after high-temperature welding, this effect is more pronounced.
3、 Shift caused by improper operation
Surface mounting accuracy issue: The accuracy of the surface mounting machine directly affects the placement of components. If the accuracy of the SMT machine is insufficient or not calibrated correctly, it may cause component displacement.
Human error: Any negligence or improper operation by the operator during the SMT process, such as excessive SMT pressure or speed, may cause component displacement.
4、 Displacement caused by material quality issues
Component quality issues: If the manufacturing quality of components is not up to standard, such as uneven pins and inaccurate dimensions, it is easy to experience displacement during the SMT process.
PCB board quality issues: The flatness and surface treatment of the PCB board can also affect the placement of components. If there are quality issues with the PCB board, such as warping, uneven surface, etc., it may cause component displacement.
5、 Displacement caused by welding issues
Thermal stress during welding: During the welding process, slight displacement of components may occur due to thermal expansion, contraction, and thermal stress.
Poor welding quality: If the welding quality is poor, such as incomplete solder joints, virtual soldering, etc., then in the subsequent use process, the components are easily displaced due to weak welding.
6、 Displacement caused by other factors
Static electricity impact: Static electricity may cause minor movement or rotation of components during the SMT process.
Design issue: If the design of the PCB board is unreasonable, such as overly compact component layout and lack of necessary fixing measures, it may also cause component displacement during use.
To avoid the occurrence of component displacement, it is necessary to control and improve from multiple aspects, including improving the accuracy and stability of the SMT machine, strengthening the training and management of operators, strictly controlling the quality of raw materials, and optimizing the design of PCB boards.
