Advanced packaging is critical to building semiconductor chips that meet the demands of the future. But more will be needed if the U.S. microelectronics industry is to reach its full potential.
Mark Shortt
The man who would later become the founder of Intel, Gordon Moore, made a statement in the 1960s that would become the guiding light of the semiconductor industry for several decades. Moore suggested that the ability to double the number of transistors on an integrated circuit every two years could enable the production of “ever more powerful semiconductor chips with greater cost efficiencies,” according to a November 2021 IPC summary report, An Analysis of the North American Semiconductor and Advanced Packaging Ecosystem: Rebuilding U.S. Capabilities for the 21st Century.
But nothing stays the same forever, and what became known as Moore’s Law is no exception. Recognizing the technological and economic limits of Moore’s Law, the semiconductor industry is now striking out in new directions in its quest to make better, more powerful chips.
“Silicon advancements have slowed, along with economic efficiencies,” IPC said in its report. “Instead, semiconductor designers are increasingly taking advantage of advancement of electronic interconnection with the packaging to achieve greater functionality and economic efficiencies they previously realized through silicon scaling.”
Today, university researchers are collaborating with chip manufacturers to develop ways to combine chips with different functions into a single system via techniques like heterogeneous integration and fan-out wafer-level packaging. These advanced packaging methods are now the hottest area of chip research and development, and figure to remain so as domestic interest in chip manufacturing continues to soar.
“Semiconductor chips, on their own, while expensive, while impressive, while technologically advanced, are actually quite useless without that packaging around them,” said Matt Kelly, chief technologist at IPC, in a video titled, Advanced Packaging of Semiconductors: The Need to Build an Industrial Ecosystem, on IPC’s website. “So, advanced packaging is the rest of that electronic component.”
Semiconductor Research Corporation President and CEO Todd Younkin summarized why advanced packaging is the subject of so much R&D today.
“Advanced packaging is really critical because the combination of performance, reliability, cost, and functionality that future consumers are really demanding can only be met by integrating silicon chips through an advanced packaging process,” Younkin said in the video.
Because of their fragility, semiconductor chips need to be protected from “thermal and mechanical stresses during operation,” according to the IPC summary report. Protection from these stresses comes in the form of packaging that uses plastics and other materials, the report said.
But advancements in packaging today are about more than protecting chips from heat and external forces, like loads and impacts. Researchers, chip manufacturers, and engineering innovators are working to develop packaging techniques that enable chips to operate with greater accuracy, security, and faster processing speeds, and are supercharging their performance with artificial intelligence (AI). Their techniques include heterogeneous integration, in which multiple chiplets are integrated into a single package, according to IPC.
In her article, Georgia Tech Is at the Leading Edge of Semiconductor Research, Tess Malone of Georgia Tech Research News wrote that Muhannad Bakir, a professor in the university’s School of Electrical and Computer Engineering (ECE), “is creating new packaging designs as director of the 3D Systems Packaging Research Center.” Bakir’s packaging technique of choice: heterogeneous integration.
“The goal is to enable the interconnection of multiple chiplets of various functionalities to provide flexibility in fabrication and design, improved scalability, reduced development time, and reduced cost,” Bakir said in the article by Malone.
The practice of stacking chips with different functions into a single package is known as three-dimensional heterogeneous integration (3DHi). Draper, an engineering innovation company, is leveraging 3DHi to enable faster designing and building of microelectronic components at its recently opened advanced packaging facility in St. Petersburg, Florida. Draper’s 3DHi microsystems are reported to provide “advanced security, high precision, high accuracy, and peak performance in harsh environments,” the company said in a release.
“In answering our customers’ call for secure, mission-unique microelectronics solutions, we’ve created an advanced packaging facility that drives high-mix production of heterogeneous microchips, invites production runs from open foundry customers, and contributes to the nation’s supply of defense-grade microelectronics,” said Draper President and CEO Jerry M. Wohletz, Ph.D., in the release. “It also provides our teams with the onshore manufacturing resources they need to continue delivering products impactful to the Draper mission.”
In addition to building a strong advanced packaging ecosystem in the United States, IPC is working with the Printed Circuit Board Association of America (PCBAA) to address critical needs for domestic manufacturers of integrated circuit (IC) substrates and printed circuit board (PCB) assemblies.
“As a leading global trade association serving the electronics manufacturing industry, IPC works with the industry to develop strong global and regional manufacturing eco-systems and resilient supply chains,” IPC’s website stated. “Advanced semiconductor packaging requires IC substrate fabrication and directly impacts future PCB technology and assembly processes.”
Founded in 2021 by domestic microelectronics manufacturers, the Printed Circuit Board Association of America is a consortium of U.S.-based companies that advocate for U.S. production of PCBs and their constituent materials. It also works to protect the domestic PCB supply chain.
“PCBs are the central nervous system of microelectronics,” according to PCBAA’s website. “Without PCBs, computer chips cannot communicate with the devices or systems they power. From everyday consumer electronics to critical national defense systems, modern technology depends on PCBs.”