The assembly method and process flow of SMT mainly depend on the type of surface mount component (SMA), the type of components used and the condition of the assembly equipment. In general SMA can be divided into single and double mixed and mixed 3 types of surface mount 6 assembly. Different types of SMA assembly methods are different, the same type of SMA assembly can also be different.

First, single side mixed assembly mode:

The single mixed assembly, namely SMC/SMD and the element (17HC) distribution mixed in different side of PCB, but it is only one side welding surface. This kind of assembly methods are single side PCB and wave soldering (now generally use double wave soldering) process.

Second, double-sided hybrid assembly:

Double sided hybrid assembly is that SMC/SMD and THC can be mixed in the same side of the PCB distribution, while SMC/SMD can also be distributed on the PCB side. Double side hybrid assembly uses double-sided PCB, double wave soldering or reflow soldering.

This type of assembly is due to a single or double sided SMC/SMD in the PCB, and the difficult to assemble the surface of the lead into the assembly of components, so the assembly density is quite high.

Third, the whole surface assembly

Full surface assembly means that only SMC/SMD on PCB without THC. Due to the current components have not yet fully realized SMT, the practical application of this assembly is not much. This type of assembly is usually performed on thin wire PCB or ceramic substrates by means of fine pitch devices and reflow soldering processes.