SMT Placement Processing Flow and Key Process Requirements

In the electronics manufacturing industry, SMT (Surface Mount Technology) placement processing is a crucial process. It ensures that electronic components are precisely and efficiently placed on circuit boards, thus guaranteeing the quality and performance of products. Today, Hunan Charmhigh Electromechanical will elaborate on the detailed process flow and key process requirements of SMT placement processing.

I. SMT Placement Processing Flow

Solder Paste Printing

The first step in SMT processing is to print solder paste on the circuit board. This process is completed by a professional solder paste printer, which uses mechanical fixtures to precisely position the PCB and stencil. Then, the solder paste is evenly applied to each open area on the stencil. After removing the stencil, the solder paste remains precisely on the PCB pads, ready for subsequent component placement.

SMT Placement

After solder paste printing, the PCB board is transported to the SMT placement machine. This high-precision equipment can accurately place various surface-mount components onto predetermined positions on the PCB board according to preset programs.

Reflow Soldering

After component placement, the PCB board enters the reflow soldering oven. This oven has multiple temperature zones inside, which precisely control the temperature and time to melt and solidify the solder paste, thus firmly fixing the components onto the PCB board.

AOI Inspection

To ensure soldering quality, AOI (Automated Optical Inspection) equipment conducts a comprehensive inspection of the soldered PCB board. This equipment can identify and mark any potential issues such as missing solder joints, incorrect placement, or cold solder joints.

Through-hole Component Soldering

For components requiring through-hole soldering, wave soldering or manual soldering is typically used. Wave soldering utilizes a wave soldering oven, which can efficiently solder a large number of through-hole components.

Final Inspection and Functional Testing

After all soldering steps are completed, the PCBA board undergoes final inspection and functional testing. This process simulates the actual operating environment of the product and conducts a comprehensive evaluation of the electrical characteristics of the PCBA board to ensure it meets design requirements.

II. Key Process Requirements for SMT Placement

Component Matching

The primary requirement of SMT placement processing is to ensure that the type, model, nominal value, and polarity of components at each assembly position number fully comply with the product's assembly drawing and BOM requirements.

Component Integrity

Placed components must remain intact and free of any form of damage, as any damage may affect the performance and reliability of the product.

Solder Paste Application

The solder terminals or pins of components should be immersed in solder paste to a depth of at least half their thickness. The amount of solder paste extrusion should be strictly controlled, with the extrusion length for general components less than 0.2mm and for narrow-pitch components less than 0.1mm.

Alignment and Centering

The terminals or pins of components must be aligned and centered with the pad pattern. Although reflow soldering has a certain self-positioning effect, the accuracy of placement position remains a crucial factor in ensuring soldering quality.

By following these key process requirements, SMT placement processing can be ensured to be efficient, accurate, and reliable, providing a solid foundation for the manufacturing of electronic products.

Hunan Charmhigh Electromechanical is a professional manufacturer of placement machines. If you have a demand for SMT placement machines, please contact us, and we will provide you with efficient and professional services. If you wish to become our local dealer, we will provide you with mutually beneficial and win-win agency solutions.WhatsApp : +8618100733752 / WeChat : 86 18100733752 / Skype : 86 18100733752