The minor editor explains the reason why solder beads appear in SMT
Along with the popularity of the electronic product industry, there is also the electronic processing industry. Therefore, SMT chip processing has become the core of the electronic industry. How the SMT chip proofing process directly determines the quality of the printed circuit board. Therefore, the purpose of many enterprises to develop the sample chip is actually to improve the quality of electronic products. Today, what we want to say is the reason for the production of tin beads in SMT chip processing.
First, tin beads are occasionally encountered in SMT chip proofing. The appearance of tin beads means that there are problems in the process, and there are many reasons for them. Here we will introduce them one by one. First of all, if the solder beads are mainly concentrated on one side of the chip resistance capacitance component or near the IC pin of the patch, it is necessary to consider whether the solder paste is beyond the print pad due to extrusion and other reasons. In this way, the extra solder paste can not be melted together and finally separated during welding. Therefore, the solder beads we see appear. In this case, it is necessary to see whether the solder paste is extruded and how to operate.
Second, if the solder bead is on both sides of the chip component, it is usually because the amount of solder is relatively large, because the solder exceeds, so the solder bead is formed. If the amount of solder is too much, it will be squeezed to the bottom of the insulator, and then it will be hot melted during flow soldering, but it will be separated from the pad due to the force, so that after cooling, tin beads, or even multiple tin beads, will be formed.
Third, if tin beads are not caused by the two people mentioned earlier in SMT chip proofing, it is necessary to consider that there is a problem in the design of the steel mesh opening and the shape of the bonding pad, and it is also necessary to clean the steel mesh and improve the accuracy of SMT chip equipment. In most cases, tin beads are caused by too much solder paste.
Just mentioned is the reason for the occurrence of solder beads in the SMT chip proofing process. In case of solder beads, it is recommended to check them one by one in order. Because the production of solder beads affects the quality of SMT chip processing, attention should be paid to them.
PCB manufacturers, PCB designers, and PCBA processors explain the reasons for SMT solder beads.