Presentation at European 3D TSV Summit charts road to IC test

The evolution of from SoCs and sensors onto 3D ICs is presenting quality and test challenges, according to James Quinn, VP of sales and marketing at Multitest. He outlined those challenges in a presentation titled “3D Technology Fusion—Is KGD Good Enough?”

Delivering his presentation January 23 at the European 3D TSV Summit, Quinn said SoCs are fabricated in established processes with test standards and proven test equipment. Moving on to sensors and MEMS, however can require the addition of mechanical stimulus during the test process.

Early MEMS devices, he said, implemented automotive safety features, and manufacturers faced strict IC qualification and test requirements. ASPs were high, few standards existed, and manufacturing required custom-designed test equipment or dedicated stimulus modules added to standard equipment. Being first to market gave vendors a competitive advantage.

Now, Quinn said, we are seeing the “sensorization” of consumer electronics. In addition to Wii and various cellphone sensors, we now have, for example, an electronic fork that nags you if you eat too much, a sensor that can accurately measure fruits’ ripeness, and Rx Timer Cap, which shows how long it’s been since you’ve last taken your prescription medication.

Sensors are everywhere, Quinn said. They need to be delivered in high volumes, they have shortened life cycles, and they must work with a variety multi-DOF stimuli. And, of course, consumer applications are cost-sensitive. Such requirements, he said, raise questions relating to MEMS fusion: how to scale, how to ramp, and how to be profitable. Quinn called for leveraging experience, building on proven solutions. In addition, he advised collaboration.

With the move to 3D ICs, Quinn said, KGD is not good enough to meet either consumer applications (with mobile form factors and smart-power requirements) or high-end applications. The complexity of 3D assembly, he said, will require ways to reduce scrap costs, avoid corruption of good stacks, and detect assembly defects. In such an environment, he said, test becomes part of process control, assuring prompt identification of process-inherent failures.

For best cost of test of 3D devices, Quinn said, manufacturers should acquire a reliable supply chain for all elements in the stack, ensuring quality and traceability; leverage process synergies across all test phases; establish data links; reduce complexity at final test; assure jint cooperation among supply chain; employ DFT; and build on established equipment.

The theme of the European 3D TSV Summit was “On the Road towards Manufacturing.” The future, Quinn concluded, is the next exit.

If you (like me) were unable to get to Grenoble for Quinn's presentation, you can view an online version here.