A semi-automatic cylindrical solder paste printing machine

Abstract

The invention relates to the technical field of printing machines, and discloses a semi-automatic cylindrical solder paste printing machine, which comprises a fixed side plate 1, a plate chain conveyor belt, a PCB board and a discharge plate. Through the setting of the stencil and the squeegee, the contact pressure between the stencil and the squeegee remains constant within a certain range, and the pressure on the solder paste remains relatively constant, reducing pressure fluctuations and ensuring that the solder paste passes through the stencil. The amount is the same, so that the solder paste printing is kept relatively consistent, and the printing quality of the same batch of PCB boards is improved. , the solder paste detaches from the template and adheres to the PCB without lifting the template away from the PCB, thereby ensuring a constant distance and pressure between the template and the PCB, reducing errors caused by repeated positioning, and further improving printing quality. And the setting of the three makes the printing process continue, and the printing speed is improved.

Description

technical field [0001] The invention relates to the technical field of printing machines, in particular to a semi-automatic cylindrical solder paste printing machine. Background technique [0002] Surface Mount Technology (SMT for short) has the advantages of easy automated production, high assembly density, small size, good high-frequency characteristics, and low cost, and has been widely used, and solder paste printing is at the forefront of the SMT process and is the entire SMT process. One of the key processes in the process is mostly printed by semi-automatic solder paste printers. The principle is: solder paste is a thixotropic fluid with viscosity. Pressure, pushes the solder paste to roll in front of the squeegee, and generates the pressure required to inject the solder paste into the mesh or leak hole. The viscous friction of the solder paste causes the solder paste to shear at the junction of the squeegee and the stencil. The viscosity of the solder paste decrease...

AI Technical Summary

Problems solved by technology

[0003] The pressure between the squeegee and the stencil is an important parameter for the quality of solder paste printing. If the pressure is too small, the amount of solder paste on the PCB pad will be insufficient or even the solder paste will be off-printed. If the pressure of the squeegee is too high, the solder paste on the pad will be damaged. If the paste is too thin, it may even damage the stencil. In production, the scraper needs to be repeatedly separated from the stencil and then in contact again. As a result, the pressure between the scraper and the stencil cannot be kept consistent during repeated contact, and there is a certain deviation, which will lead to PCB board The amount of solder paste on the pad is different, so that the quality of subsequent soldering is not the same, resulting in a decline in product quality. Aggregation, printing, separation and aggregation each time, requires high positioning accuracy, once a deviation occurs, it will cause different printing results and reduce the printing quality

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