Analysis of the Causes of Component Displacement in SMT Assembly Production and Handling Methods

 
With the development of technology and the improvement of living standards, the pursuit of electronic products is increasingly trending towards miniaturization and precision. In SMT small-batch patching processing plants, traditional DIP plug-ins no longer play as significant a role in small, compact PCBA as SMT patching, especially for large-scale and highly integrated ICs. The precision industry requires meticulous attention to both material usage and processing steps, as even the slightest error can render the entire device inoperable. Therefore, every step in the patching process must be carefully observed.
SMT patching processing, namely Surface Mount Technology (SMT), is the most popular technology and process in the current electronic assembly industry. Surface Mount Technology for electronic circuits, also known as surface mounting or surface installation technology, primarily aims to accurately mount surface-mounted components onto fixed positions of a PCB. However, during patching processing, some process issues may arise, affecting patching quality—such as component displacement. Component displacement in patching processing is a precursor to several other problems during the welding process and requires attention. So, what are the causes of component displacement in patching processing?
Causes of Component Displacement in Patching Processing:
  1. Solder paste has a limited shelf life. After exceeding the usage period, the flux in it deteriorates, leading to poor soldering.
  1. The solder paste itself has insufficient viscosity, causing component displacement due to oscillations or shaking during handling.
  1. Excessive flux content in the solder paste leads to component displacement due to the flow of excess flux during reflow soldering.
  1. Component displacement caused by vibration or improper handling during transportation after printing and patching.
  1. In patching processing, the suction nozzle's air pressure is not adjusted properly, with insufficient pressure causing component displacement.
  1. Mechanical issues with the patching machine itself result in incorrect component placement.
Once component displacement occurs in patching processing, it affects the circuit board's performance. Therefore, during processing, it is necessary to understand the causes of component displacement and address them specifically.
Targeted Solutions Based on Specific Causes:
  1. Strictly calibrate positioning coordinates to ensure the accuracy of component mounting.
  1. Use high-quality, high-adhesion solder paste to increase SMT mounting pressure and bonding force for components.
  1. Select appropriate solder paste to prevent solder paste collapse, with the solder paste having a suitable flux content.
  1. Adjust the speed of the fan motor.
In fact, in the reflow soldering of SMT patching processing, besides component displacement, there are many other possible defects, such as stand-up and flip-over issues. However, these defects can be resolved by starting from circuit board design—from excellent PCB fabrication to meticulous execution in responsible SMT patching processing—addressing everything from components to solder paste and processes to fundamentally improve reflow soldering quality and prevent component displacement.
Want to know more? Contact me at sales9@hitechpcb.com. From Sandy

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