As US sanctions continue to intensify, China's semiconductor industry has been looking for ways to bypass the curbs. Chiplet, a modular approach of chip design that integrates multiple circuit blocks on an interposer, is one of the alternatives being explored by the Chinese semiconductor industry to stay competitive.
Actually, chiplet has been a key part of the global semiconductor industry's push to go beyond Moore's Law, given its ability to integrate chips of various nodes and functions to achieve better systematic performace, at lower costs and with faster time to market. The momentum has lately picked up speed as leading vendors like Intel, AMD and Apple begin to introduce chiplet-based products. In March this year, for example, Apple released its M1 Ultra chip that integrates two M1 Max SoCs using TSMC's integrated fan-out (InFO) packaging technology.
Even DARPA, an R&D agency under the US Department of Defense, has been researching chiplet under its Common Heterogeneous Integration and Intellectual Property Reuse Strategies (CHIPS) program, aiming to develop design tools and integration standards to enable reusable IP blocks.
According to the consultancy firm Omdia, the market for chiplet will reach US$5.8 billion in 2024, and exceed US$57 billion by 2035.
In China, the chiplet technology has been regarded by some as a way to leapfrog semiconductor development, with leading foundry SMIC already recognizing the potential of chiplet technology. In a speech in early 2021, then SMIC vice-chairman Shang-Yi Chiang noted that only a few products would adopt the most cutting-edge process nodes, and that China relatively lagged in packaging technology. Consequently, SMIC would simultaneously develop advanced process nodes and advanced packaging technology.
Following Chiang's departure, SMIC's concrete progress on chiplet has been largely in the shadow. However, SMIC has been partnering with China's leading chip packaging company Jiangsu Changjiang Electronics Tech (JCET) in advanced packaging.
Back in 2014, the two set up a joint venture, SJ Semiconductor to focus on advanced packaging, including 3DIC. However, SMIC's inclusion in the US Entity List also jeopardized the JV, prompting SMIC to transfer all its stakes in SJ Semiconductor to other entities in 2021 in an attempt to have it removed from the Entity List.
JCET itself has been making progress in chiplet development. The company reportedly recruited a lot of talent specialized in advanced packaging from Huawei's HiSilicon, one of the earliest Chinese companies looking into chiplet. In 2021, JCET released its XDFOI ultra-high-density fan-out packaging solutions. According to JCET, the solution will offer diverse options of heterogeneous integration for SoC and chiplets alike, and volume production is expected in the second half of 2022. In July this year, JCET has also realized the integrated packaging of CPU, GPU and RF chipsets, in addition to the packaging of 4nm chips for mobile phones, according to the company.
Apart from JCET, Chinese startups have also begun to look into chiplet technology. Universal Chiplet Interconnect Express (UCIe), an industrial alliance formed by leading players like intel, AMD, Arm, Qualcomm, TSMC, ASE, Samsung, Google, Meta and Microsoft to build an open standard for the interconnect between chiplets, is seeing more Chinese members like VeriSilicon Holdings, Xpeedic, and Akrostar Technology. In August, China's Alibaba also became the first Chinese company joining UCIe's board.
In a June conference, Wayne Dai, founder and chairman of VeriSilicon, referred chiplet technology as crucial to the buildup of China's "strategic stockpile." In short, China can stockpile chiplets to build more powerful processors in the future, overcoming the present bottlenecks. Qinfen Hao, the secretary general of China Computer Interconnect Technology Alliance (CCITA), also claimed that chiplet technology could enable chips based on 28nm process to reach a performance level akin to those built on 16nm or even 7nm nodes.
Some are skeptical, nevertheless. Dan Hutcheson, the vice chair of Techinsights, regarded "chiplet" as a new marketing term that was gaining wide traction in China, as the country is relatively adept at packaging technology, according to a EET China report. According to Hutcheson, chiplet alone could not solve the current bottlenecks faced by Chinese chip manufacturing industry. Shao Jun Wei, a leading expert of Chinese chip industry at Tsinghua University, also regarded chiplet as "supplementary" rather than a replacement of advanced manufacturing processes, according to EET China.
"Even though it is not difficult for China to develop advanced packaging technology, heterogeneous integration is only beneficial to certain products", a former SMIC official told DIGITMES Asia. "China cannot neglect the development of advanced process technology."
Article translated by Misha Lu
