PCBgogo

Today, we will share a widely used method for controlling process fluctuations in the industry—Statistical Process Control (SPC).

SPC, which stands for Statistical Process Control, is a technique that uses statistical methods to monitor and control key quality characteristics in the production process in real-time. By collecting and analyzing data from the production process, SPC can help us promptly detect process anomalies, predict potential quality risks, and take corresponding measures to adjust, thereby keeping process fluctuations within a stable range.

In the PCBA process, the application of SPC can be unfolded in the following aspects:

Identification and Monitoring of Key Quality Characteristics

First, we need to identify the key quality characteristics in the PCBA process, such as the thickness of solder paste printing, placement accuracy, soldering quality, etc. These characteristics directly affect the performance and reliability of the final product. Then, we can use SPC software to monitor these characteristics in real-time and create control charts.

For example, taking the thickness of solder paste printing as an example, we can measure the thickness of solder paste at different positions through regular sampling inspections and input the data into the SPC software. The software will automatically calculate statistical measures such as the mean and range and draw control charts. By observing the control charts, we can intuitively understand the fluctuation of the solder paste printing thickness. If data points exceed the control limits or show abnormal trends, it indicates that there may be a problem with the process that needs to be investigated and addressed promptly.

Analysis and Improvement of Process Capability

SPC is not only used for real-time monitoring but also for analyzing process capability. By calculating the process capability index (Cpk), we can assess whether the current process meets the design requirements. If the Cpk value is too low, it indicates that the process capability is insufficient and needs to be improved.

For example, PCBGOGO widely applies SPC technology in PCBA production. By continuously monitoring key process parameters such as reflow soldering temperature profiles, they promptly identify and address potential quality risks. Through in-depth data analysis, they continuously optimize process parameters, enhance process capability, and ensure the high quality and stability of products.

Tracing and Preventing Causes of Abnormalities

When the SPC control chart shows abnormalities, we need to promptly investigate and identify the causes. This requires a comprehensive analysis in combination with the actual production site conditions, such as equipment status, operator actions, material batches, etc. By tracing the causes of abnormalities, we can take targeted measures to prevent similar problems from recurring.

Continuous Improvement and Optimization

SPC is a process of continuous improvement. By continuously collecting and analyzing data, we can gain a deep understanding of the fluctuation patterns of the PCBA process and continuously optimize process parameters to enhance the stability and reliability of the process.