New energy charging pile fast charging motherboard SMT patch processing

New energy charging pile fast charging motherboard SMT patch processing

Assembly process of SMT patch processing

　　The assembly method of SMT patch processing and its process flow mainly depend on the type of surface assembly component (SMA), the type of components used and the conditions of the assembly equipment. It can be divided into single-sided assembly, double-sided assembly, single-sided mixed packaging, double-sided mixed packaging and other assembly methods. Different types of assembly methods are different, and the same type of assembly method may also be different.

Which is better for SMT patch processing

　　SMT single-sided assembly process: incoming inspection => screen printing solder paste (point patch adhesive) => patch => drying (curing) => reflow soldering => cleaning => inspection => rework.

SMT processing double-sided assembly process: 1, incoming inspection => PCB A side screen printing solder paste (dot patch adhesive) => SMD PCB B side screen printing solder paste (dot patch adhesive) => paste Piece => Drying => Reflow soldering (preferably only for B side => cleaning => inspection => rework). 2. B: incoming inspection => PCB side A screen printing solder paste (dot patch) => patch => drying (curing) => A side reflow soldering => cleaning => flip board = PCB B Surface mount adhesive => patch => curing => B-side wave soldering => cleaning => inspection => rework).

The single-sided hybrid assembly method of SMT patch processing is as follows:

　　 The first type is SMT patch processing single-sided mixed assembly, that is, SMC/SMD and through-hole plug-in components (17HC) are distributed and mixed on different sides of the PCB, but the soldering surface is only one side. This type of assembly method uses single-sided PCB and wave soldering (now generally uses double wave soldering) process, there are two specific assembly methods.

　　 (1) First paste method. The first assembly method is called the first attach method, that is, the SMC/SMD is placed on the B side (welding side) of the PCB, and then the THC is inserted on the A side.

　　 (2) Post-sticking method. The second method of assembly is called the post-attach method, which is to insert THC on the A side of the PCB first, and then mount the SMD on the B side.

SMT patch processing double-sided mixed assembly method:

　　 The second category is SMT patch processing double-sided mixed assembly, SMC/SMD and T.HC can be mixed and distributed on the same side of the PCB, and at the same time, SMC/SMD can also be distributed on both sides of the .PCB. Double-sided mixed assembly uses double-sided PCB, double wave soldering or reflow soldering. In this type of assembly method, there is also the difference between SMC/SMD first or later. Generally, the choice is based on the type of SMC/SMD and the size of the PCB. Generally, the first method is more. Two types of assembly methods are commonly used for this type of assembly.

　　 (1) SMC/SMD and iFHC are on the same side, SMC/SMD and THC are on the same side of the PCB.

　　 (2) In the different side modes of SMC/SMD and iFHC, put the surface mount integrated chip (SMIC) and THC on the A side of the PCB, and put the SMC and small outline transistor (SOT) on the B side.

　　This type of SMT patch processing and assembly method is because the SMC/SMD is mounted on one or both sides of the PCB, and the leaded components that are difficult to surface assemble are inserted into the assembly, so the assembly density is quite high.