The circuit board used for assembly is a single-sided PCB. Single-sided mixed assembly means that SMT patches and dip plug-in components are mixed on different sides of the PCB. The welding surface is a single side, and the patch surface is another single side. This kind of assembly method adopts single-sided PCB and wave soldering process, and there are two specific assembly methods:

1. Paste first and then insert: that is, smc/smd is first pasted on the B side of PCB, and then thc is inserted on the a side.

2. Insert first and then paste: that is, insert THC on side a of PCB first, and then paste SMD on side B.

The circuit board used for the assembly of this PCBA processing is a double-sided PCB. SMT patches and dip plug-ins can be mixed and distributed on the same side or both sides of PCB. There are also differences between SMC / SMD sticking first and SMC / SMD sticking later in this kind of assembly method. Generally, it is reasonable to choose according to the type of smc/smd and the size of PCB, and the first paste method is usually used. There are two assembly methods commonly used in this class:

1. SMT components and dip components are on the same side: SMT chip components and dip plug-in components are on the same side of PCB; Dip plug-in components are available on one or both sides. Generally, smc/smd is pasted first and then dip is inserted.

2. There are SMT chip components on one and both sides of dip components: put the surface assembled integrated chip (SMIC) and tht on side a of PCB, and SMC and small shape transistor (SOT) on side B.