PCBA Tech - About quality management in SMT patch processing

Quality management in SMT patch processing is an important method to achieve high quality, low cost and high efficiency.

1. The smt chip processing plant sets quality goals

SMT patch requires printed circuit boards to print solder paste, mount components, and finally the pass rate of the surface assembly board from the reflow soldering furnace to reach or close to 100%, that is, it is required to achieve zero (no) defects or close to Zero defect reflow welding quality, while also requiring all solder joints to reach a certain mechanical strength. Only such products can achieve high quality and high reliability. The quality goal is measurable. At present, for the best companies in the world, the defect rate of SMT can be controlled to less than or equal to 10ppm (ie 10x106), which is the goal pursued by every SMT processing plant. Usually, the short-term, mid-term, and long-term goals can be formulated according to the difficulty of processing products, equipment conditions and technological level of the company.

2. Process method

1. Prepare the company's specification documents, including DFM company specifications, general processes, inspection standards, audit and review systems, etc. 2. Through system management and continuous monitoring and control, high-quality SMT products are realized, and SMT production capacity and efficiency are improved. 3. Implement full process control. SMT product design-purchase control-production process control-quality inspection-drawing and document management-product protection-service provision-data analysis-personnel training.

3. Production process control

The production process directly affects the quality of the product. Therefore, all factors that affect the quality of the production process, such as process parameters, personnel, equipment, materials, processing, monitoring and testing methods, and the environment, should be controlled to keep them under controlled conditions. The controlled conditions are as follows: 1. Design schematic diagrams, assembly drawings, samples, packaging requirements, etc. 2. Formulate product process documents or work instructions, such as process cards, operating specifications, inspection and test instructions, etc. 3. Production equipment, tooling, fixtures, molds, shafts, etc. are always qualified and effective. 4. Configure and use appropriate monitoring and measuring devices to control these characteristics within the specified or permitted range. 5. There are clear quality control points. The key processes of SMT are solder paste printing, patching, reflow soldering and wave soldering. The requirements for quality control points (quality control points) are: there are quality control points on the spot, standardized quality control point documents, and control Data recording is correct, timely, and clear. The control data is analyzed and processed, and PDCA and traceable sMT production are regularly assessed. In the production of PDCA and traceable sMT, quota management should be carried out on welding sound, patch glue, and component loss, as a key process control One of the content.