Academician Xu Juyan: Chips will drive the future of the semiconductor industry

At the 2019 China Semiconductor Packaging and Testing Technology and Market Annual Conference held in Wuxi, Xu Juyan, an academician of the Chinese Academy of Engineering, delivered a speech entitled "Return to the Tao - Packaging Changes the Chip Industry", pointing out that historical events are like buds on branches, which always emerge and bear fruit where they are supposed to grow.

For monolithic integration, small is "big", and the guiding principle of "big" is to cram more components into integrated circuits. However, with the continuous advancement of monolithic integration, Academician Xu Juyan believes that it has "deviated" from the original intention - the basic requirement of electronic systems is to use the most economical resources to achieve the most ideal functions. This includes the optimization of internal architecture and external environment, the balance of high performance and low power consumption, and the integration of small size and long life.

In the past few years, integrated circuits have always emphasized PPA, that is, higher performance, lower power consumption, and smaller area. Academician Xu Juyan believes that it is time to revise this logical direction.

Academician Xu Juyan further pointed out that classic 2D scaling has "exhausted" existing technical resources. Putting more components into integrated circuits brings problems such as long cycle (18-36 months), large investment, high risk, repeatability (most chips have PCIe DDR interfaces), large area (complexity and low yield), and many resources (seamless collaboration of SoC teams). Now the method of doubling performance through nodes has failed, so we need to move beyond monolithic integration. The maturity of three-dimensional integration and the victory of multi-chip over single chip have become an opportunity to move beyond monolithic integration.

This is also an opportunity to achieve a spiral recovery. However, it is worth noting that Academician Xu Juyan pointed out that from "MCM" to "MCM", the "C" in the former represents soft IP, and the "C" in the latter represents hard IP.

As early as 2015, a Chinese team "tested the waters" of modular chips.

In 2017, a project called CHIPS was established in ERI. Its vision is to create a diverse chiplet ecosystem with discrete and appropriate node manufacturing, develop modular chips and assemble them (and other heterogeneous components) into a series of design tools, integration standards and IP blocks for larger systems (modules). Participating organizations include Intel, Micron, Cadence, Synopsys, Boeing, the University of Michigan, etc.

This has also been responded to by all parties. In October 2018, seven companies established the ODSA organization. By the first half of this year, the number has reached 53. Its goals are to formulate open standards for chiplets, promote the formation of a chiplet ecosystem, and give birth to low-cost SoC alternatives.

In addition, many companies have created their own ecosystems, such as Intel, which aims to promote chiplet standards.

The "diversion" from monolithic integration to multi-chip heterogeneous packaging integration technology in the post-Moore era is an important trend. Academician Xu Juyan pointed out that heterogeneous 3D packaging provides higher bandwidth, lower power, lower cost and more flexible form factors; it integrates the flexibility of process selection, architecture design and business model. Therefore, it reduces the challenge of high NRE of monolithic SoC and wins the benefit of fast time to market.

Academician Xu Juyan expressed his optimism about the potential of multi-chip heterogeneous integration technology.

However, Academician Xu Juyan also pointed out that the chiplet model still faces many challenges. The key to its success lies in the standards and interfaces of the chiplets. For example, there is still a lack of standard methods for assembling or packaging chiplets, and the interconnection scheme between chiplets needs to be selected. It is necessary to establish verification and testing methods for chiplets to communicate design and manufacturing, and it is necessary to establish supply chain relationships for chiplet manufacturing, packaging and integrators.

In addition, Academician Xu Juyan also introduced the domestic advanced packaging trends.

Academician Xu Juyan emphasized that chiplets will drive the future of the semiconductor industry, and this is an upcoming MCP tsunami. In addition, large chip manufacturers are turning to chiplets, which is a major change in direction.

Therefore, whether an open industrial ecosystem will be formed in a few years and whether a chip ecosystem promotion alliance should be established are issues worthy of consideration by the industry.