How many stages does the lead-free solder paste reflow process consist of?

For many people, it seems that they are not very familiar with the process flow of lead-free solder paste reflow. In factLead-free solder pasteDuring the heating treatment process, solder paste reflux can be divided into the following stages. Next, JJY solder Paste Manufacturer will explain it to everyone:

Under normal circumstances, the lead-free solder paste reflow process is divided into five stages:

1It is suitable for evaporation of solvents that meet the required viscosity index and printing characteristics, and the working temperature increase must be slow(Approximately per second3°C)To avoid boiling and splashing, and to prevent the formation of small tin beads. Moreover, some individual components are relatively sensitive to internal structural stress. If the surface working temperature of the components rises too quickly, it may lead to breakage.

2Once the flux becomes active, the chemical cleaning behavior begins. Both water-soluble flux and no-wash rosin flux will exhibit the same cleaning behavior, only with slightly different working temperatures. Thoroughly remove oxides and individual contaminants from the metal materials and tin-containing particulate matter to be fused. Good solder joints in metallurgy require a "clean" surface.

3When the working temperature keeps rising, the solder particles first dissolve independently and then undergo the "lamp-like" operation process of liquefaction and surface tin absorption. In this way, tin is covered on various possible surfaces and solder joints begin to appear.

4This stage is extremely crucial. When a single solder particle completely dissolves and fuses together to form liquid tin, if the gap between the component and the pad is too large at this time, separation is highly likely to occur, resulting in an open circuit of the solder spot.

5During the cooling stage, if the cooling speed is fast, the strength of the solder dots will be slightly greater, but it should not cause working temperature stress in the internal structure of the component too quickly.

JJY Solder Paste Manufacturer mainly engages in lead-free solder paste.SMTSurface mount solder pasteLEDWe are engaged in the research and development, production and supply of solder pastes, lead-free solder wires, wave soldering rods and other solder solders. For more knowledge about electronic soldering, you can follow and contact us. Welcome to interact with us.