What are ‘chiplets’, US technological bet – 05/15/2023 – Market

For more than 50 years, computer chip designers have relied primarily on one tactic to improve performance: They have shrunk electronic components to put more power into each piece of silicon.

Then, more than a decade ago, engineers at chipmaker Advanced Micro Devices (AMD) began testing a radical idea. Rather than designing a large microprocessor with lots of tiny transistors, they envisioned creating a microprocessor made up of smaller chips that would be packaged together to function like an electronic brain.

The concept, sometimes referred to as “chiplets,” has been enthusiastically embraced by AMD, Apple, Amazon, Tesla, IBM, and Intel, all of which have released such products. “Chiplets” quickly gained traction because smaller chips are cheaper to manufacture, and packages of them can outperform any single slice of silicon.

The strategy, based on advanced packaging technology, has since become an essential tool in enabling semiconductor progress. And it represents one of the biggest changes in many years for an industry that drives innovation in fields like artificial intelligence, self-driving cars and military hardware.

“The packaging is where the action is going to happen,” said Subramanian Iyer, a professor of electrical and computer engineering at the University of California, Los Angeles, who helped create the “chiplet” concept. He adds that “this is happening because, really, there is no other way”.

The problem is that this type of packaging, as well as the manufacture of the chips themselves, is predominantly dominated by companies in Asia. Although the United States accounts for about 12% of the world’s semiconductor production, US companies supply just 3% of chip packages, according to the IPC, an industry association.

This issue has now placed “chiplets” at the center of US industrial policy-making. The CHIPS Act, a $52 billion grant package passed in the third quarter of last year, was seen as an initiative by President Joe Biden to reinvigorate domestic chip production by providing money to build more sophisticated factories, known as “fabs”. But part of the package was also aimed at encouraging factories that focus on advanced packaging in the United States, to capture a larger share of this essential process.

“As chips get smaller, the way to arrange them, which is packaging, becomes more and more important and we need to get this done in the United States,” Commerce Secretary Gina Raimondo said in a speech. at Georgetown University in February.

The Commerce Department is already accepting requests for manufacturing grants under the CHIPS Act, and that includes chip packaging plants. It is also committing funds to a specific research program for advanced packaging.

Some chip packaging companies are moving quickly to secure funding. One such is Integra Technologies in Wichita, Kansas, which announced plans for a $1.8 billion expansion to its facilities but said it was dependent on receiving federal grants. Amkor Technology, an Arizona-based packaging service that has most of its operations in Asia, also said it was in talks with customers and government officials about a manufacturing presence in the United States.

Chip packaging is not a new concept, and “chiplets” are just the latest incarnation of the idea, using advances in technology that help package chips closer to each other – side by side or stacked on top of each other – together. with faster electrical connections between them.

“What’s unique about chiplets is the way they’re electrically connected,” said Richard Otte, chief executive of Promex Industries, a chip packaging service in Santa Clara, California.

Chips can’t do anything without a way to connect them to other components, which means they have to be placed in some kind of package that can transmit electrical signals. This process begins after factories complete the initial manufacturing phase, which can create hundreds of chips based on a silicon wafer. After this wafer is cut, the individual chips are typically glued to a fundamental base layer called a substrate, capable of conducting electrical signals.

This combination is then coated with protective plastic, forming a package that can be connected to a circuit board, which is essential for connecting other components in a system.

These processes originally required a lot of manual labor, which led Silicon Valley companies to shift packaging to lower-wage Asian countries more than 50 years ago. Most chips are typically flown in for packaging services in countries such as Taiwan, Malaysia, South Korea and China.

Since then, advances in packaging have gained importance due to diminishing returns from Moore’s Law, the term used to summarize the process of chip miniaturization that has driven progress in Silicon Valley for decades. The name of this law is due to Gordon Moore, one of the founders of Intel, who in an article published in 1965 described how quickly companies would be able to double the number of transistors on a typical chip, which would allow for performance improvement at a lower cost.

Today, however, smaller transistors aren’t necessarily cheaper, in part because building factories for cutting-edge chips can cost between $10 billion and $20 billion. The design of large and complex chips is also expensive and they tend to suffer more manufacturing defects, at a time when companies in areas such as generative artificial intelligence want a greater number of transistors than what can be placed today. on the biggest chips that manufacturing machines allow.

“The natural response to this is to pack more into one package,” said Anirudh Devgan, chief executive of Cadence Design Systems, whose software is used to design conventional chips as well as chiplet-style products.

Synopsys, a rival company, said it was tracking more than 140 customer designs based on packaging multiple chips into a single set. Up to 80% of microprocessors will use a “chiplet”-style design by 2027, according to the Yole Group, a market research firm.

AMD and the 146 billion transistors

Companies today often design all of the “chiplets” in one package, along with their own connection technology. But industry organizations are working on technical standards so companies can more easily assemble products with “chiplets” from different manufacturers.

New technology today is mainly used for extreme performance. Intel recently introduced a processor called Ponte Vecchio, with 47 “chiplets”, which will be used in a powerful supercomputer at the Argonne National Laboratory, near Chicago.

In January, AMD unveiled plans for an unusual product, the MI300, which combines standard “chiplets” for computing with ones designed for computer graphics, along with a large set of memory chips. That processor, destined to power another advanced supercomputer at Lawrence Livermore National Laboratory, has 146 billion transistors, compared with tens of billions in the most advanced conventional chips.

Sam Naffziger, AMD’s senior vice president, said it wasn’t easy for the company to bet on “chiplets” in its server chip business. The complexities of packaging were a major hurdle, he said, which was eventually overcome with help from an undisclosed partner.

But the “chiplets” paid off for AMD. The company has sold more than 12 million chips based on the idea since 2017, according to Mercury Research, and has become a leading supplier of the microprocessors that power the web.

Packaging services still need a third party to provide the necessary substrates for “chiplets” to connect to circuit boards and to each other. One company driving the chiplet boom is Taiwan Semiconductor Manufacturing, which already makes chips for AMD and hundreds of other companies and offers an advanced silicon-based substrate known as an “interposer.”

Intel has been developing similar technology, as well as improving on cheaper conventional plastic substrates, an approach favored by some such as Silicon Valley startup Eliyan. Intel has also been developing new packaging prototypes under a Pentagon program, and is hoping to gain CHIPS Act support for a new packaging pilot plant.

But the United States does not have large manufacturers of these substrates, which are mainly produced in Asia and evolved from technologies used in making circuit boards. Many US companies have also left the business, another concern that industry groups hope will spur federal funding to help board suppliers get started making substrates.

In March, Biden determined that advanced packaging and domestic production of circuit boards were essential to national security and announced $50 million in Defense Production Act funding for American and Canadian companies in these areas.

Even with the subsidies, putting together all the necessary elements to reduce the US dependence on Asian companies “is a big challenge,” said Andreas Olofsson, who led a Department of Defense research effort in this area before founding a technology startup. marshaling call Zero ASIC. “You don’t have suppliers. You don’t have a workforce. You don’t have equipment. You have to more or less start from scratch.”

(translation by Paulo Migliacci)