inSMTIn surface mount technology (SMT) processing, the solder bead phenomenon is one of the main defects. There are many reasons for the occurrence of solder beads, and it is not easy to control. The following is JJYSolder paste manufacturerLet me introduce it to everyonesmtWhy are there tin beads during the process?

1The thickness and quantity of solder paste printing

inSMTIn surface mount technology (SMT) processing, the printing thickness of solder paste is a key parameter. If the solder paste is too thick or too much, it will collapse, leading to the formation of solder beads. When making templates, the size of the holes in the template is generally determined by the size of the solder pads. Under normal circumstances, to avoid excessive solder paste printing, the size of the printing holes is designed to be smaller than the corresponding contact area of the solder pads10％Within this range, this will alleviate the tin bead phenomenon to a certain extent.

2Reflow soldering

Generally speaking,smtThe reflow soldering process can be divided into four stages: preheating, holding, soldering and cooling. During the preheating process, vaporization occurs inside the solder paste. When vaporization happens, if the bonding force between the metal powders in the solder paste is less than the force generated by vaporization, a small amount of solder powder will flow down from the solder pad, and even some solder powder may fly out. During the welding process, this part of the welding powder will also melt and formSMTSolder beads in surface mount technology (SMT) processing.

3"Environment"

smtThe working environment for manufacturing can also affect the formation of tin beads, for example, whenPCBAThe storage environment of the board is too humid or it has been stored in a humid environment for too long. In severe cases, it can even bePCBAFine water droplets were found in the vacuum bag of the board, and this moisture will affectPCBAThe soldering effect of surface mount technology (SMT) processing eventually leads to the formation of solder beads.

In the electronic processing factorysmtThere are still many reasons in manufacturing that can affect the formation of tin beads, such as steel mesh cleaning.SMTThe repeatability accuracy of the surface mount technology (SMT) machine, the reflow oven temperature curve, the placement pressure, etc.

As a 15-year-old veteran solder paste manufacturer, JJY has been committed to the research and development, production and sales of solder paste. Our solder paste is of stable quality, without solder disconnection, false soldering or monument erection. No residue, Wuxi beads, bright, full, firm solder joints with excellent electrical conductivity. If you have any needs, please feel free to contact us.