Printing Solder Paste Test

To ensure the quality of the solder assembly, it needs to monitor the printing solder paste testing parameters: printing speed/squeegee pressure/printing gap/separation distance / clean frequency/paste thickness/viscosity. All these parameters should be met the specification.

Paste neither is a solid nor a liquid, it is a mixed paste object, the main component is the solder powder (tin powder) and the flux (flux)

(1) Printing Red Glue

The red glue is usually kept in the refrigerator at the optimum temperature. It should be removed and thawed at room temperature before use. And then open and stir to use. The dosage should not exceed two hours. It also needs to check if the red glue printed on the bottom of the PCB mounting components with full and moderate. So that there is no infiltration of red glue mount to the pad and connectors (or pins). At the same time, the red glue can make the components bonding and fasten. So that when wave welding, the components are not easy to fall.

(2) Printing Solder Paste

The solder paste is usually kept at the refrigerator’s proper temperature. Before use, it should be removed from the refrigerator and thawed to room temperature. And then open and stir until uniform, smooth, and put into use. It also needs to check that the solder paste is uniform amount printed on the PCB pads, with or without collapse, and scattered at the surface of the PCB to ensure good reflow of welding components. And there are no beads scattered on the plate surface.