Statistical Process Control / SPC

Salland Engineering BV the Netherlands

What is Statistical Process Control

Statistical Process Control, also known as SPC, is a set of procedures using statistical techniques to improve the quality of products. Since the 1970's it is widely used in the whole industry.

Before the1970's the industry produced its products based on quantity. The demand of new products was high. Only a few managers saw the need of using statistical techniques for improving the quality of their products.
During the 70's local markets turned to global. More and more the industry got companion from cheaper and better products form other parts of the world.
That time the industry became aware that product quality is a very important issue to become a winner on the market.
This was the turning point for using statistical analysis as a measurement tool into a production environment.

Since then Statistical Process Control is one of the most important tools to improve efficiency and quality of the industrial production process.

Process control techniques.

The basic part of Statistical Process Control is the use of an effective monitoring and investigation system.

Concept is to compare the state of the process of today, with the control limits of historical information, or a calculated model of the process.
When measurements of the actual process are outside the defined limits, it is time for further investigation to conclude what happened and how it can be solved.
Target is to ensure that the shipped products meet their specifications, and product quality is guaranteed.

Statistical Process Control in the Semiconductor industry.

In the semiconductor industry the collection of process data is a major task to verify if the process is according specification. With Automatic Test Equipment a lot of data is collected and saved for further statistical analysis. It is important to have such process data and use it for controlling the various elements of the production process.
Most of this data is analysed by using huge databases and large computer systems. A quick analysis on the test floor is not always possible. With simple statistical analysis tools the Production Engineers and Test engineers can use the already available measurement data to investigate if the production process is running as expected.

Improving the generation and use of statistical data

Using SPC techniques is getting easier. Automatic data collection with tester equipment and the availability of various statistical software helps to create 'real time' statistical information, which can be used for direct process control.
Statistical software is an important tool to do a statistical analysis with more ease.
Using software improves the speed of creating actual statistical data. It prevents making mistakes and helps the user by alerting when data is not according specifications.

Statistical Process Control and SEDana

With SEDana from Salland Engineering the most common used elements of SPC are direct available on the ATE test floor.
The software application is designed for use as a 'statistical toolbox' in the semiconductor industry.
It is based on the practical experience of test and production engineers who are working in the semiconductor industry.
SEDana uses raw datasets form ATE equipment and generates with this data typical SPC tables, graphs and reports for the semiconductor industry.
SEDana is the fastest and shortest possible connection between raw data and a good statistical analysis on the test floor.