The PCB Assembly method of SMT Chip processing Technology
According to the specific requirements of the assembly products and the conditions of the assembly equipment, it is the basis of the efficient and low-cost assembly production to select the appropriate assembly mode. It is the main content of the SMT chip processing design. The so-called surface assembly technology means that the components of the sheet structure or miniaturized components suitable for surface assembly. According to the requirements of the circuit they are placed on the surface of the pcb and assembled by the welding process such as reflow welding or wave peak welding. It will constitute electronic components with assembly technology.
On the traditional THT printed circuit board, the components and solder joints are located on both sides of the board respectively, while on the SMT printed circuit board, the solder joint and the component are on the same side of the board. Therefore, on the SMT printed circuit board, the through hole is only used to connect the wires on both sides of the circuit board, the number of holes is much smaller and the diameter of the hole is much smaller, so the assembly density of the circuit board can be greatly increased. The following SMT patch finishing factory introduces the assembly method of SMT patch processing technology.
In the first type, SMC/SMD and through hole components are mixed on different sides of PCB, but the welding surface is only one-sided. This kind of assembly adopts single side PCB and wave peak welding and there are two kinds of assembly methods.
(1) Pre-attachment method. The first method of assembly is called the first mount method, the SMC/SMD is pasted on the B side of the PCB (welded joint) and then the THC is inserted on the A surface.
(2) Post-sticking method. The second type of assembly is called backmount, the THC is inserted on the A side of the PCB and then the SMD is mounted on the B side.
SMC/SMD and THC can be mixed on the same side of PCB, and SMC/SMD can also be distributed on both sides of PCB. Double-sided PCB, double-wave soldering or reflow welding is used for two-sided hybrid assembly. In this kind of assembly, there is also the difference between the first and the latter SMC/SMD. Generally, according to the type of SMC/SMD and the size of PCB, the first paste method is usually used.
The assembly mode and technological process of SMT patch processing mainly depend on the type of surface assembly group, the type of components used and the conditions of assembly equipment. In general, SMA can be divided into three types: one side, two sides and full surface assembly. Different types of SMA have different assembly methods, and the same type of SMA can also be assembled differently.
