The poor SMT patches produced by SMT patch processing manufacturers mainly include device deflection, displacement, turnover, vertical piece, missing paste, damage and throwing. The causes of these defects are usually related to the startup, commissioning, operation and daily maintenance of the patch machine. Therefore, the core of SMT chip processing technology in PCB and PCBA processing plants is how to use SMT chip machine correctly. The displacement of large electronic components is closely related to the downward speed of PCB workbench.
The design of the mounter used now has been very perfect. A large part of the poor mounter is mainly related to the deformation of PCB and z-stroke control. When using the mounter, the control of the z-direction travel of the mounter is mainly pressure type and line program. The pressure type relies on the pressure to control the stroke, while the running program relies on the spring buffer to control. Both types of control methods have an upper limit of the adjustment range.
If we bow the PCB, generally no error will occur, but once it is concave, it may cause adverse phenomena such as deflection, turnover and displacement of components. The support of PCBA and the setting of Z-direction travel are the key points of patch process control.
