**What is SPC?**
SPC stands for Statistical Process Control. It primarily refers to the use of statistical analysis techniques for real-time monitoring of the production process. SPC helps to scientifically differentiate between random fluctuations and abnormal variations in product quality during manufacturing. This early warning system allows production managers to promptly address abnormal trends, ensuring that the recovery process remains stable and ultimately enhancing quality control.
In the PCBA production process, fluctuations in product dimensions are unavoidable. These variations stem from fundamental factors such as personnel, machinery, materials, and methods.
and the environment. There are two types of fluctuations: normal and abnormal. Normal fluctuations arise from accidental factors (unavoidable influences). They have minimal impact on product quality, are technically challenging to eliminate, and their economic elimination is often unjustifiable. In contrast, abnormal fluctuations stem from systemic issues (abnormal factors). These significantly affect product quality, but measures can be taken to avoid and rectify them. The aim of process control is to eliminate and prevent abnormal fluctuations, ensuring the process remains within the bounds of normal fluctuations.
What is the role of SPC in PCBA production?
1. Product categories and product information
Each PCBA processing company is unique and possesses distinct characteristics, necessitating flexibility in planning product categories and materials. Product categories can be classified based on the specific attributes of the company’s offerings. For instance, some companies differentiate between semi-finished and finished products.
2. Inspection and inspection stations
The primary function of the inspection department is to evaluate the product and determine its compliance with quality standards. Quality inspection assesses product quality and identifies issues. However, it is not the inspection department’s responsibility to investigate the underlying causes of non-compliance or to determine how to achieve quality improvements; these tasks fall under the purview of the technical and production departments.
During the initial stages of the SPC project design, it is essential to identify and define the inspection stations for products or materials. This allows for quick identification of the stage or station where issues may arise during production.
3. Definition of defect categories and codes
Throughout the PCBA production process, various defects may occur, such as misalignment in printing, solder paste bridging, component displacement, open circuits, and tin beads. It is crucial to establish standardized defect categories that are uniformly recognized and used within the company. This facilitates the implementation of the SPC project, enabling everyone to clearly identify defect categories. By standardizing defect classifications, we can minimize discrepancies caused by the ambiguous nature of problem identification and resolution.
