Singapore-based Silicon Box specializes in chiplets, an increasingly popular way of making high-performing chips by packing smaller chips tightly together and shortening their electrical connections. To help ramp up production, the three-year-old startup recently raised $200 million in a Series B round from industry giants and its own billionaire cofounders.
As tech giants battle to build ever-more powerful AI systems with smaller and faster chips, one newly minted unicorn startup—cofounded by industry veterans, including the billionaire husband-and-wife duo behind Nasdaq-listed Marvell Technology—aims to hasten a potential paradigm shift towards larger and even faster chips using chiplet technology.
To help chiplet technology become mainstream, Singapore-based Silicon Box announced in January that it had raised $200 million in a Series B funding round, with participation from BlueRun Ventures’ tech-focused growth equity arm BRV Capital, Event Horizon Capital, Maverick Capital, Prasedium Capital, Tokyo-based electronics giant TDK’s venture arm TDK Ventures and Taiwan-based semiconductor maker United Microelectronics Corp.’s UMC Capital.
The round also included participation from the startup’s three cofounders, billionaires Sehat Sutardja and Weili Dai—the couple who previously cofounded Marvell Technology—and Byung Joon Han, former CEO of Stats ChipPac, a subsidiary of semiconductor testing and packaging giant JCET. With its Series B, the three-year-old startup’s total funding reached $410 million and its valuation reached $1.08 billion, making it Singapore’s latest unicorn, or startup valued at over $1 billion.
“Given the rise of AI and massive demand, the traditional, monolithic integrated circuit design architecture is not sustainable,” says Henry Huang, investment director at TDK Ventures, in a video interview. “You need to have this chiplet concept to make it more powerful, but at a lower cost…we see that [Silicon Box] has a clear technical advantage over many other competitors.”
To Huang, who holds a Ph.D. in electrical and computer engineering, Silicon Box stands a chance against the incumbent giants that offer advanced packaging to make chiplets, including billionaire Morris Chang’s Taiwan Semiconductor Manufacturing Co. (TSMC), which produces the vast majority of advanced chips today. As a foundry, TSMC chiefly manufactures chips for other companies that design them, including billionaire Lisa Su’s AMD and billionaire Jensen Huang’s Nvidia.
“There are a few guys doing semiconductor packaging, but none of them are able to do the kind of packaging that TSMC are able to do,” adds Huang. “When we’re looking at Silicon Box, we think that this is the only company out there able to do at least on par, or similar to TSMC.”
The fresh capital will go towards Silicon Box’s manufacturing capabilities and global expansion. Last July, Silicon Box cut the ribbon on a 750,000-square-foot semiconductor fab in Singapore’s eastern region of Tampines, home to several important industrial parks. Three months later, in October, the $2 billion facility began producing chiplets. Silicon Box declined to disclose its customers but said its chiplets are used in hot AI fields such as large language model and generative AI, high-performance computing, mobile computing, data centers and electric vehicles.
“We aspire to become the global No. 1, the globally most recognized company, in terms of technology, as well as operational excellence,” says Han, who serves as CEO of Silicon Box, in a video interview. So far, the startup claims its proprietary sub-5-micron technology can optimize power usage and that it can reduce manufacturing costs by up to 90%.
To Han, the company also benefits from being situated in Singapore, a geopolitically “neutral” location where the government has been investing heavily in the semiconductor space. “Singapore, if you look really carefully, is a place you can attract global talent,” he adds.
Silicon Box specializes in advanced packaging to make chiplets, a type of chip that uses interchangeable components, as opposed to monolithic ones. These interchangeable components can be tailored for specific functions, and like Lego pieces, added together to form a single unit. Known as heterogeneous integration, the process of combining specialized chiplet parts can “deliver levels of overall performance that were previously impossible,” according to a report jointly published by BCG and the Washington-based Semiconductor Industry Association in November 2022.
Chiplet-based designs may also allow engineers “to be more creative,” says Sutardja, chairman of Silicon Box, as an industry-wide race to increase the number of transistors capable of fitting on each chip faces new hurdles.
“We need to build chips differently,” he says in a separate video interview. “It might not be too obvious for people outside the industry…every year, the cost to build our single-chip devices has been increasing not incrementally, but exponentially.”
An early pioneer of chiplet technology, Sutardja says there was initially “not much urgency” for companies to look beyond monolithic chips. In 2015, the then-CEO of Marvell Technology introduced his vision for a modular, chiplet-based design called “MoChi,” an amalgamation of “modular” and “chip” that evokes the popular Japanese rice snack.
The idea didn’t take off. Widely deemed too expensive and complex, MoChi and other modular designs remained unpopular. Mark Papermaster, CTO of AMD, expressed support but encouraged Sutardja to rename MoChi to “chiplets,” a longstanding industry term for disaggregated circuits. (“He asked, ‘what the hell is MoChi?’,” quips Sutardja.)
Almost a decade later, Sutardja’s vision has proved prescient as industry leaders have rushed to embrace chiplets. AMD launched its first chiplet-based design in 2015, and in 2021, unveiled a 3D design tailored for high-performance computers. (Dai says Papermaster thanked Sutardja for spearheading MoChi.) In 2022, a coalition of semiconductor giants including AMD, Arm, Intel and billionaire Jay Y. Lee’s Samsung published the Universal Chiplet Interconnect Express (UCIe), a set of technical specifications serving as an open-source industry standard for chiplet manufacturing. Shortly after the UCIe’s release, Marvell joined the coalition, followed by Nvidia. Last December, Intel launched its first fully chiplet-based design, having tinkered with similar designs for close to a decade.
“If you look at today’s chiplets, from the design side, pretty much the majority of companies are moving in that direction, and the bottleneck is the advanced packaging,” says Dai, who is based in Las Vegas with Sutardja. “So this is where we’re here to help the industry to grow faster.”
Silicon Box says its competitors are primarily other outsourced semiconductor assembly and test vendors (OSATs), which help to package and test chips that foundries produce. Leading OSATs include billionaire Jason Chang’s Taiwan-based ASE Technology and Arizona-based, Nasdaq-listed Amkor Technology, where Han, Silicon Box’s CEO, was previously director of R&D. TSMC, in particular, is a “natural collaborator,” Silicon Box said in an emailed statement.
“The foundries also need us,” says Dai, whose role at Marvell involved forming key industry partnerships. “We are in a very neutral position, where we can put this thing together from multiple foundries.”
Still, chips face technical challenges as they scale up, a phenomenon widely known in the semiconductor industry as the “red brick wall.” The closer that different components are on one circuit, the more heat these components generate, complicating operations. For chiplets, where components of varying shapes and functions are placed on the same base, these thermal issues may be more pressing, according to a paper on a potential chiplet cooling system published at the 2023 conference of the Institute of Electrical and Electronics Engineers.
Over the past two years, investors across Asia have tapped startups to capture the rapidly expanding market for AI chips. Recent funding activity has taken place in South Korea, where earlier in February, AI chip startup Rebellions announced it raised $124 million in a Series B funding round, bringing its valuation to $650 million. Last November, Seoul- and Seattle-based chip design startup MangoBoost raised $55 million in a Series A funding round led by IMM Investment, a prominent investor on last year’s Forbes Asia 100 to Watch list that has backed the likes of billionaire Bom Kim’s Coupang and Chang Byung-gyu’s Krafton.
Despite naysayers and fierce competition across the industry, there are “not many alternatives” to the work that Silicon Box does, Han, the CEO, says. “We are trying to make a technology which is so disruptive that they can address all the markets.”
“I usually don’t try to convince skeptics,” Han adds. “We just smile.”
