DFT Digest

This is DFT Digest, so we talk about Design-for-Test a lot. Makes sense, right? But the International Test Conference is not just DFT, in fact it’s really mostly Test. As much as we DFTers want to bring the tester into the chip, the fact is that it doesn’t always make it. And tons of great research and development goes into test technology and methodology to be able to evaluate the biggest and fastest chips and boards that we can conjure up.

I’ve tried to gather feedback from friends who attended and participated in ITC this year. One who has offered his pre-show as well as post-show insights is Ken Butler of Texas Instruments. Here’s some of what he said about his week:

• Someone said that Adaptive Test turned out to be a de facto theme and I guess I would tend to agree. The three major players in this space (Optimal Test, Pintail, and Test Advantage) were all out in force on the exhibits floor.
• Seems like scan chain debug is growing in importance - There were several papers on that subject.
• There were more reliability papers this year than in past years. Timing and at-speed topics were well-represented.
• A few papers on logic BIST, again maybe a slight resurgence.
• Ben Bennetts did an entertaining look at the history of test from back in the 50’s to the present as part of his swan song as he retires.

Ken Butler is a TI fellow, and works in the product reliability group, on development of outlier techniques, and test quality modeling. He gave the first in a series of invited addresses at ITC this year, called Pinning down this elusive thing called ‘adaptive test’. These are fascinating topics, especially when you’re working for a company that produces and tests millions of devices per month. Cutting the cost of test, while maintaining quality can mean the difference between profits and losses. Design for test is just one way to accomplish that. By tracking and studying process variations and how they affect the outcome of test, the test itself can be optimized, and adapted, to provide the best quality with minimal cost.

So many interesting topics, so little time…