Wave soldering refers to the soft soldering material that will melt tin alloy (lead), electric pump, or electromagnetic pump flow into the design requirements of solder wave, can be formed by the injection of nitrogen to solder pool, make the PCB with components in advance through the solder wave, components, and PCB solder welding end or pin of the mechanical and electrical connection between soft soldering. With the enhancement of people’s awareness of environmental protection, a new welding process has been developed. The previous use of tin-lead alloy, but lead is heavy metal to the human body has a great harm. Thus, the lead-free process was promoted, using * tin-silver-copper alloy * and special flux, and the welding temperature required a higher preheating temperature.

 

Reflow soldering technology in the field of electronics manufacturing is not strange, we use the computer in the various components on the board is welded on the circuit board through this process, the device’s internal have a heating circuit, heated to a high enough temperature to air or nitrogen after blowing has good components of circuit boards, components on both sides of the solder melts and motherboard bonding.

The advantages of this process are that the temperature is easily controlled, oxidation is avoided during welding, and manufacturing costs are more easily controlled. Due to the continuous miniaturization of PCB in electronic products, the flake components appear, and the traditional welding method can not meet the needs.

At first, reflow soldering was only used in the assembly of hybrid integrated circuit boards. Most of the components were chip capacitors, chip inductors, mount transistors, and diodes. With the development of SMT technology and the emergence of SMC and SMD, reflow soldering technology and equipment as a part of SMT technology have been developed accordingly. Its application is becoming more and more extensive, and it has been applied in almost all electronic product fields.

 

The sequence of wave soldering and reflow soldering

Wave soldering and reflow soldering process sequence, in fact, from the order of circuit board assembly principle, assembly principle is to first assemble small components and then assemble large components. The patch component is much smaller than the plug-in component, and the circuit board is assembled in order from small to large, so it must be reflow soldering and then wave soldering.

The patch components of reflow soldering are relatively small pins mounted on the circuit board components, wave soldering is relatively large plug-in components with pins, plug-in components are inserted on the circuit board occupies a relatively large space. If the wave soldering process occurs first, the reflow soldering process for the patch element is performed in the same way. According to the assembly sequence of circuit board components, reflow soldering is followed by wave soldering.