1、 Red glue problem in SMT mounting machine

SMT Mounter if processing red glue viscosity is insufficient, handling vibration and other factors will make the component displacement. If the solder paste or patch paste exceeds the service life, its components will deteriorate, and its inherent characteristics will change or disappear, which will also cause installation problems. Solution: select the right solder paste and patch paste, and keep and use them as needed.

2、 The accuracy of printing machine is not enough

The quality of printing accuracy is related to many factors, in addition to the setting and correction of screen and substrate and the processing accuracy, it is also related to the experience and proficiency of printing operators. First of all, the main reason of SMT Mounter installation offset is the positioning offset of the substrate before printing. Secondly, the amount of solder paste printed by the operator is also related to the control of printing pressure. If the control is not appropriate, it will lead to SMT Mounter installation defects. Solution: from the modification and processing of steel mesh, printing positioning to the skill training of operators, the printing accuracy of solder paste is improved.

3、 Handling problems

In the rotation process after printing and patching, SMT Mounter produces vibration, proper storage and handling. Solution: standardize the layout and rotation mode of printed circuit board after printing and patch.

4、 Pressure or mechanical problems

During the processing of SMT, the air pressure of the suction nozzle is not adjusted properly, the pressure is insufficient, or it becomes a mechanical problem of the SMT, and the installation position of the components is wrong.

For the above installation deviation problem, in the actual production of SMT chip machining, within the specified deviation range can be allowed. In general, if the offset of SMT Mounter side is considered to be able to allow the front-end offset of a small value less than 1 / 4 of the solderable end of the package or less than 1 / 4 of the pad width, the overlap of the solderable end of the package and the pad of SMT Mounter shall not exceed the allowable angular offset of the solderable end of the pad; SMT Mounter generally consists of the welding area and the welding cross-section length of the component To judge, as long as the welding area is more than 2 / 3 of the weldable end, more than 2 / 3 of the weldable end, and the welding cross-section length is less than 2 / 3 of the weldable end, it can be allowed.