Imec/Besi collaborate on bonding technology for 3D IC platform

January 20, 2014 // By Graham Prophet
A joint development effort aims to provide one of the necessary steps for realising 3D ICs as a volume technology: thermocompression technology for high-accuracy narrow-pitch bonding.

Nanoelectronics research centre imec; and Besi (BE Semiconductor Industries, Netherlands and Switzerland), an equipment supplier for the semiconductor and electronics industries, have announced they are joining forces to develop a thermocompression bonding solution for narrow-pitch die-to-die and die-to-wafer bonding with high accuracy and high throughput. Through this collaboration, imec and Besi will pave the way to industrial adoption of thermocompression bonding for 3D IC manufacturing.

3D IC technology, stacking multiple dies into a single device, aims to increase the functionality and performance of next-generation integrated circuits while reducing footprint and power consumption. It is a key technology to enable the next generation of portable electronics, such as smartphones and tablets, which require smaller ICs that consume less power.

One of the key challenges to making 3D IC manufacturing a reality is the development of high-throughput automated process flow for narrow-pitch, high-accuracy die-to-die and die-to-wafer bonding. Flip chip and reflow soldering, which are currently combined for bonding, require lenient bonding accuracy on large bump pitches (around 150-50 µm bump pitch). Bump pitches need to further scale down to 40-10 µm to achieve a sufficiently high performance. This needs high accuracy in bonding within the range of 1-2um @3-sigma. Moreover, an automatic process flow is essential for industrial adoption. Thermocompression bonding is a method that enables this high bonding accuracy on narrow bump pitches, although with this comes long cycle times due to temperature and pressure profiles and processing methods which hinder industrial adoption of this technology up to now.

Imec and Besi will conduct joint research to develop a high-throughput thermocompression bonder in an automated process flow, with high accuracy and shorter cycle times, paving the way to enabling a manufacturable 3D, 2.5D and 2.5D/3D hybrid technology.