PCBA Assembly Methods: SMT and DIP
PCBA (Printed Circuit Board Assembly) processing involves a complete set of steps including PCB manufacturing, SMT (Surface Mount Technology) processing, DIP (Dual In-line Package) insertion, quality inspection, testing, and assembly to form a finished electronic product. This process is referred to as PCBA processing, and the resulting circuit board after processing is called a PCBA. There are various types of PCBA, and several assembly methods used in PCBA processing. Below, WonderfulPCB, a professional PCBA factory, provides a brief introduction to some common assembly methods.
Single-Sided Hybrid Assembly
This assembly method uses a single-sided PCB. In a single-sided hybrid assembly, SMT components and DIP components are distributed on different sides of the PCB. The soldering side is isolated to one side, and the SMT components are placed on the other side. This method employs single-sided PCB and wave soldering technology. There are two specific assembly methods:
- SMT First, DIP Second: SMT components (SMC/SMD) are mounted on the B-side of the PCB first, and then DIP components (THC) are inserted on the A-side.
- DIP First, SMT Second: DIP components (THC) are inserted on the A-side of the PCB first, and then SMT components (SMD) are mounted on the B-side.
Double-Sided Hybrid Assembly
This type of PCBA assembly uses a double-sided PCB. SMT and DIP components can be mixed on the same side or both sides of the PCB. In this assembly method, there is also a distinction between mounting SMT components first or later. The choice depends on the type of SMC/SMD and the size of the PCB. Typically, the “SMT first” method is more commonly used. Two common assembly methods include:
- SMT and DIP on the Same Side: Both SMT components and DIP components are on the same side of the PCB, though DIP components may also appear on both sides. In this method, SMT components (SMC/SMD) are generally mounted first, followed by DIP insertion.
- DIP on One Side, SMT on Both Sides: Surface mount integrated circuits (SMIC) and THT components are placed on the A-side of the PCB, while SMC and small outline transistors (SOT) are placed on the B-side.
Full Surface-Mount Assembly
In this assembly type, all PCBs are single-sided or double-sided, and only SMT components are used, with no THT components. Not all components have been fully SMT-optimized, so this assembly method is less commonly used in practice. There are two assembly methods:
- Single-Sided Surface-Mount Assembly.
- Double-Sided Surface-Mount Assembly.
