Research And Development On Real Time Monitor System Of Vlsi Circuit Testing

The purpose of integrated circuit testing is to ensure that each grain or packaged chip can meet the characteristics and design specifications of the device,usually including verification of timing,voltage,current,and function.It has the characteristics of high technical and solution complexity,and high software and hardware integration.Any factors such as poor testing machines,accessories,testing environment,and machine operation techniques can lead to serious testing reliability issues,including over kill,under kill,test value drift,abnormal adjustment parameters,and a large number of product scrapping.Testing factories suffer losses of up to millions of yuan annually due to reliability issues.Therefore,in order to ensure the accuracy and reliability of test results,it is of great significance to develop a real-time monitor system for integrated circuit testing to improve the technology and timing of testing problem discovery,reduce the duration and loss of testing faults.This project mainly focuses on the key content of real-time data incremental extraction technology for integrated circuit testing,fault identification and prediction algorithm design,monitoring system design and programming development,etc.,enabling the system to automatically monitor multiple testing equipment in factories online,achieving the goal of real-time detection of reliability issues and alarm.Firstly,conduct structural research on the binary data file STDF generated by integrated circuit testing,and complete the development of script programs and deployment of multiple terminal testing machines.This script can achieve real-time incremental extraction of effective information from binary data files.After collecting over ten million chip test data from an integrated circuit testing factory in East China and analyzing a large amount of data,7 statistically significant effective feature indicators and monitoring algorithms were developed,including the number of consecutive failures,the number of hardware failure categories,the number of software failure categories,yield,site yield difference,parameter average,site parameter value difference,etc;Secondly,a real-time monitor system model for test data is designed,which includes three parts: device terminal script program,user monitoring indicator configuration program,and server real-time monitoring program.The terminal script program is responsible for extracting effective data from multiple test equipment terminals and writing server databases;The user configuration program is used by engineering personnel to set parameter items and control values that need to be monitored for different chips;The server-side program can monitor data uploaded from multiple terminals to the database in real-time,and perform algorithm detection and control value comparison of parameter items.The system can trigger multiple automatic alarms in case of abnormal indicators,including soft alarms(sending emails,system prompts)and hard alarms(three color light sound and light prompts,communication protocol control shutdown,and external terminal robot control shutdown).Finally,through software programming,hardware module integration,verification and debugging,the prototype development of the monitor system was completed.After the release of the above testing factory,real-time data analysis,algorithm detection,abnormal indicator monitoring,and automatic alarm functions were achieved during the integrated circuit testing process.And in the six months of operation,it has achieved a good benefit of increasing the abnormal detection rate by 30% and reducing the scrap loss amount by 45%,and the factory testing quality has been greatly improved.