Reliable chips kept affordable

Inventor Janusz Rajski from Digital Factory came to the rescue by developing a test method that used data compression to work up to 100 times faster than conventional tests.
Inventors of the Year 2018

Lifetime Achievement

The semiconductor industry was desperately seeking a new test method.
Janusz Rajski, Digital Factory

Chips are the heart of electronics, not only in computers, aircraft, cars, elevators and power stations, but also in smartphones, coffee machines and thousands of other devices. To ensure they remain reliable for the entire service lifetime, all chips are thoroughly tested before they are installed.


This was no problem until the 90s: at that time, chips still processed relatively small amounts of data, and the volumes of test data transmitted through the integrated circuit were consequently manageable. However, the ongoing improvement of their computing performance which, according to Moore's Law, roughly doubles every 18-24 months, meant that the test runs became increasingly expensive, mostly because of the time required.


As each highly integrated processor chip needs to undergo very comprehensive tests to cover billions of potential defects, the amount of test data that is stored, transferred to and computed on each chip is immense. In the compression method developed by Rajski, the test data is first unpacked on-chip and the tests computed. The chip also compresses the results and transfers them to the test system. Mentor Graphics launched the new solution at the beginning of 2000 under the name of TestKompress.


This invention resulted in numerous other developments. Mentor Graphics has acquired a number of test specialist companies and has continued to expand its market position. Rajski today is Vice President of Engineering at Mentor Graphics and an internationally known expert.