PCBA processing is a product that is processed. I believe you who follow our website must know what SMT processing is. In fact, PCBA is a PCB light board that has undergone SMT patch, THT plug-in and PCBA testing, quality inspection and assembly and other processes. A finished product formed, referred to as PCBA. Can realize the designer's design function, almost all electronic products, such as smart home, AR, VR, medical equipment, etc., need to use the PCBA board.
PCBA processing and assembly methods mainly depend on the type of surface mount components, the types of components installed, processing equipment conditions and actual production
line conditions. PCBA processing can be divided into three types of single-sided mixed assembly, double-sided mixed assembly, and full-surface assembly, a total of six assembly methods.
One, single-sided mixed
The circuit board used for assembly is a single-sided PCB. Single-sided hybrid assembly means that the SMT patch and THT plug-in components are distributed on different sides of the PCB. The soldering surface is a single side, and the patch surface is the other single side. This type of assembly method uses single-sided PCB and wave soldering (currently double wave soldering is generally used). There are two specific assembly methods:
(1) Paste first, then insert: firstly mount the SMC/SMD on the B side (welding side) of the PCB, and then insert the THC on the A side.
(2) Insert first and then paste method: first insert THC on the A side of the PCB, and then mount the SMD on the B side. This type of assembly is widely used in the assembly of TVs, radios and other products.
Two, double-sided mixed
The circuit board used for assembly is a double-sided PCB. SMT patch and DIP plug-in can be mixed and distributed on the same side or both sides of the PCB. Double-sided hybrid assembly purchases double-sided patch, double wave soldering or reflow soldering. In this type of assembly, there is also a difference between first and second SMC/SMD. Generally, it is reasonable to choose according to the type of SMC/SMD and the size of the PCB. Usually, the first paste method is more adopted. There are two commonly used assembly methods for this type:
(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 the PCB; DIP plug-in components are on one or both sides. Generally, DIP is inserted after attaching SMC/SMD.
(2) DIP components have SMT components on one side and on both sides: put the surface mount integrated chip (SMIC) and THT on the A side of the PCB, and put the SMC and the small outline transistor (SOT) on the B side.
In the above content, we introduced the single-sided and double-sided mixed assembly of PCBA processing, and then there is a full-surface assembly, assembling all circuit boards into single-sided and double-sided PCBs (or ceramic substrates). There are only SMT components on the PCB and no THT components. As the current components have not yet fully realized SMT, there are not many such assembly forms in practical applications. There are two assembly methods for this type: single-sided surface assembly and double-sided surface assembly. Do you know the assembly method of PCBA processing through the above content?