PCBA Tech - SMT placement process layout and component requirements

SMT processing factory placement process layout

The site process layout of SMT processing plants should be in line with the core concept of efficient PCBA production, with various coordination and smooth flow, maintaining a high degree of rationalization, and achieving high-efficiency SMT patch processing under the premise of orderly. How should the layout of this SMT processing plant be done?

The logistics route should be as short as possible to improve the efficiency of production and management. All kinds of articles involved in production should be classified into different categories, and fixed management should be implemented. All working areas and storage areas for various articles should be clearly marked. Many types of items that have nothing to do with the production site should be resolutely removed from the site.

The inspection content of SMT foundry materials is mainly divided into incoming material inspection, process inspection and surface assembly board inspection, etc. The quality problems found in the process inspection can be corrected through rework. The rework cost of unqualified products found after incoming inspection, solder paste printing, and pre-welding inspection is relatively low, and the impact on the reliability of electronic products is relatively small.

Process inspection, especially the first few process inspections of PCBA patch, can reduce the defect rate and scrap rate, can reduce the cost of rework/repair, and can also prevent quality hazards from the source through defect analysis.

In order to standardize the solder paste printing process in the SMT processing workshop and ensure the quality of solder paste printing, the Guangzhou PCBA processing plant has formulated the following process guidelines: The engineering department is responsible for the formulation and modification of the guidelines; responsible for setting printing parameters and improving poor processes, manufacturing departments, and quality The Ministry implements the guidelines to ensure good printing quality.

SMT factory's requirements for components processed by SMT

The main business of the SMT factory is SMT patch processing. Of course, it will also do plug-in, assembly, and testing work. Some factories will also launch OEM service, that is, they can purchase materials for customers and provide materials for customers. The components of the SMT patch processing order generally have some requirements from the processing plant. What are the requirements?

1. Shape

The shape of the components conforming to the standard vertebralization can be easily positioned, making the automated SMT processing more efficient.

2. Size

The dimensional accuracy of standard SMD components needs to match the dimensional accuracy of surface mounting technology and surface mounting structure in order to be interchangeable.

3. Electrical performance

The SMT factory's requirements for the electrical performance of the SMT components are to meet the standardization requirements, and the repeatability and stability are good, and the mechanical strength requires the process requirements of the SMT patch processing and the performance requirements of the assembly structure.

4. Heat resistance

The components need to be reflow soldered during the patch processing, and the heat resistance of the processed components needs to be able to withstand the high temperature during the soldering process.

5. The location and material properties of the external lead-out ends of SMT components should be conducive to the automated welding process, and the external structure is suitable for braid packaging, and the model or parameters are easy to identify.