IC substrates are set to enter a golden growth period driven by ever-increasing applications of 5G and AI chips solutions. To secure a preemptive presence in the market, Taiwan's leading maker Unimicron Technology has set a record capex of NT$17.2 billion (US$568.16 million) for 2020 mainly to boost its capacity for high-end ABF substrates and deepen deployments in AiP (antenna in package) technology.
The firm's vice CEO CP Lee talked about future challenges and development trends facing the IC substrate market during a recent interview with Digitimes.
Q: As AiP is a much-talked-about technology in the 5G communication era, what technical challenge will it pose to IC substrate makers?
A: The biggest difference between AiP and traditional CSP (chip scale package) is that the former requires the support of brand-new substrate materials and more-stringent production process. For IC substrate makers, AiP is a brand-new technology they should learn from the very beginning, and brand-new equipment is needed for the entire process ranging from manufacturing to final test, requiring injection of substantial investment.
While CSP process mainly adopts thin substrates, AiP technology requires thick substrates with higher layer counts, with production lines having to be adjusted correspondingly at much higher costs.
Q: AiP can be carried out via diverse packaging technologies. How will the technologies affect IC substrate makers?
A: As far as we know, TSMC has developed InFO_AiP solutions, which need substrates with fewer layers than for FC_AiP process. For IC substrate makers, producing substrates with lower layer counts is not a bad thing, at least not requiring large investments. But low investment threshold will prompt entry of newcomers, stoking intense competition.
Nevertheless, as AiP solutions feature high-frequency, high-speed performance, any new entrant has to meet three major requirements, which are quality, technology and capacity. Therefore price war for AiP-use IC substrates will not come too soon. Growing 5G handset and base station applications will drive immense demand for AiP modules, and therefore IC substrate makers will surely have their own market leeway no matter what packaging technology is required by clients.
Q: ABF substrates supply has fallen short of demand due mainly to insufficient capacity support, but what is the actual technological challenge facing the segment?
A: The biggest challenge in production of ABF substrates is that while large-size substrates with high layer counts are increasingly needed, their circuit density and blind hole numbers also have to increase simultaneously. At the moment, both TSMC's CoWoS (chip-on-wafer-on substrate) and Intel's EMIB (embedded multi-die interconnect bridge) solutions are getting larger in size to meet high bandwidth, low latency and low power consumption requirements in processing server, networking, HPC and AI chips. Accordingly, the technology, specs and management of supporting IC substrates are becoming increasingly sophisticated.
In particular, to achieve high-frequency and high-speed performance, ABF substrate materials have to be significantly upgraded, which will necessitate installation of new equipment for increasing layers and testing performance and reliability of new materials, all requiring heavy investment.
Moreover, as materials are advancing fast, every production aspect has to be constantly calibrated, making it necessary for us to build new production lines for ABF substrates, as parameters for old ones are hard to adjust and no longer suitable for producing substrates with new materials.
Q: Will there be new applications beyond current ones for ABF substrates? And will the substrates see regular supply shortages?
A: In the next 5-10 years, application demand for ABF substrates will continue to come from HPC, AI, networking and server chips segments. Also, we are quite optimistic about demand for automotive electronics applications in the future, particularly autonomous vehicles, as sensors will be massively applied to such vehicles and strong built-in computing chips will be needed to process big data.
The ABF substrate supply market will eventually be dominated by leading makers in the segment and tight supply will linger for a long time, given limited number of makers capable of handling profitable production of large-size ABF substrates with good technology and management capabilities.
Q: How do you see future development directions for the markets for ABF substrates and BT ones?
A: The ABF substrate market has a high entry barrier for newcomers, mainly heavy investments in building new production lines and developing new technology for high-end substrates. Additionally, a certain learning period will serve as another barrier for new entrants, as clients will turn to existing leading makers for the supply of substrates with ever-expanding sizes and layer counts for 2.5D and 3D packaging of heterogeneous chips solutions. Accordingly, the ABF substrate market will be increasingly dominated by leading suppliers, while the BT substrate segment may have other development patterns as it allows easier entry for newcomers.
Unimicron Technology vice CEO CP Lee
Photo: Michael Lee, Digitimes, February 2020
Article translated by Willis Ke
