SAN JOSE, Calif. IBM Corp. said it has made advances in through-silicon via packaging that will allow it to ship production chips using the new interconnect in 2008. The company will first apply the technology to power amplifiers for Wi-Fi and cellular chips and later to its Power processors, particular for its Blue Gene supercomputers.
Through-silicon vias link individual chip dice in a style similar to the way packaged chips are mounted on a printed circuit board. The chips employ vertical connections etched through a silicon wafer and filled with metal to directly attach multiple die.
The technique can shorten by 1,000 times the distance data on a chip needs to travel and allows for the addition of up to 100 times more connections, according to IBM.
"This breakthrough is a result of more than a decade of pioneering research at IBM," said Lisa Su, vice president of IBM's semiconductor research and development center, speaking in a prepared statement "This allows us to move 3-D chips from the 'lab to the fab' across a range of applications," she said.
Today chip makers routinely stack memory and logic chips, especially for cellular handsets, using a variety of package-on-package techniques that typically involve intermediate substrates and wiring layers that slow data rates and add complexity. The industry has long pursued a direct die-to-die link, however such approaches typically require expensive new materials, processes and equipment.
"There are a huge number of headaches in cost, yield and test," for through-silicon via technology, said Brandon Prior, a senior consultant with Prismark Partners, a consulting firm based in Long island specializing in packaging issues.
IBM did not immediately comment on the details of the process it employs. The company did say it is already running chips using the through-silicon-via technology in its manufacturing line and will begin sampling chips using this method to customers in the second half of 2007.
The company said it will apply the technique broadly in wireless communications chips, Power processors, Blue Gene supercomputer chips and for high-bandwidth memory.
IBM said the technique could create products with longer battery life by improving power efficiency in silicon germanium based wireless products up to 40 percent. It could also be used to deliver power closer to the individual cores in a multi-core CPU, lowering power consumption as much as 20 percent while increasing the chip's data rate.
The company is converting to the through-silicon via technology the custom PowerPC processors used in its Blue Gene supercomputers. The new chips will sport direct attachments between the processors and memory. A prototype SRAM design using the technology is being fabricated in IBM's 300-mm production line using 65nm process technology.