NUPIAO |
For years, the high-frequency filter chip market was locked down tight by overseas giants. Now, Chinese contenders are finally storming the gates.
“This year, we’re gearing up to deliver over 1 billion filter chips, and our yields are firmly sitting at 98–99%,” said Huang Hongjun, VP of Investment and Financing at AiFo Communications, during a recent stop in Guangdong for the “Vitality China Research Tour.” “Phones make up the biggest slice of our shipments—we’ve basically covered all the major brands and are shipping at scale.”
Based in Guangzhou’s Huangpu District, the company dives deep into 5G mid- and high-frequency RF filter chips. The BAW (Bulk Acoustic Wave) filter chips they’ve developed are a core component that China’s comms industry has long been choked on. AiFo is the only Chinese player—and globally the third—to have mastered the full chain of core tech for 5G mid/high-frequency BAW filters, running on an IDM model.
Before this, two American firms—Broadcom and Qorvo—had almost all the patents and market share locked up. Huang told us that by blazing their own trail with single-crystal aluminum nitride, they’ve sidestepped the patent walls those giants built with polycrystalline aluminum nitride. That’s how they solved the chokepoint problem in high-end BAW filters. Right now, AiFo has already built the world’s first 8-inch BAW filter mass-production line in Guangzhou, and its chips have made it into the supply chains of mainstream players like Samsung and ZTE, making it one of the few Chinese companies that can actually mass-produce high-performance filter chips.
A single smartphone usually packs more than 30 filter chips to cover different frequency bands. Close to 10 of those are for high-frequency bands, while the 3G/4G mid- and low-frequency bands add up to over a dozen. Huang pointed out that domestic substitution for mid- and low-frequency filters is already pretty mature. AiFo is pushing hard into 5G and higher frequencies as the core of its import-substitution drive. “We can now handle frequencies above 10 GHz. The speed is blazing fast, and the bandwidth is huge.”
As the core component in RF systems for 5G and beyond, high-frequency filter chips directly decide how well a device receives signals and resists interference. They precisely pick out useful signals in a crowded spectrum while filtering out noise and adjacent-channel crosstalk, ensuring fast data and stable calls. They also heavily influence power consumption and RF integration—making them one of the most valuable pieces of the RF front-end.
When you dig into the tech, the breakthrough really comes down to a different material path. Dr. Qian Yingda, a senior process engineer at AiFo, explained to NUPIAO that a filter chip’s job is to convert wireless signals into electrical signals. Wireless signals are essentially sound waves, or mechanical vibration energy. You need the piezoelectric effect of aluminum nitride to turn that mechanical energy into an electrical signal. Compared with the polycrystalline aluminum nitride everyone else uses, single-crystal AlN has far superior piezoelectric performance and acoustic transmission efficiency—it’s the ideal material for making high-performance BAW filters.
But cracking the material code is only step one. Getting the process right is just as tough. Huang noted that filter chips aren’t like digital chips—their performance depends on how complex the process and structure are. To support their own tech path, the company has already modified around 12 sets of semiconductor equipment to fit their needs, and some of the core equipment was developed in-house. At the same time, they’ve localized their material supply. To keep up with demand, they’re expanding capacity. The 50-mu headquarters building in Guangzhou has finished civil works and is now getting its cleanroom fit-out.
Back in 2015, AiFo kicked off its first pilot line for 5G SABAR® filter chips, churning out 500,000 units a month. By 2020, they had a full-scale production line running, hitting 30 million units a month. Today, AiFo has nearly 100 filter chip models in stable mass production.
The direct payoff of owning your tech? Costs come way down. Dr. Yi Xinyan, AiFo’s VP of R&D, told NUPIAO that the company set up its own wafer fabrication line, bringing raw materials under control. They’ve been systematically pushing on improving material growth efficiency, simplifying chip fabrication, and localizing key materials. The result: overall costs are 30–40% lower than similar overseas solutions. And compared with international peers, the key performance metrics of SABAR® chips have jumped by over 20%.
As capacity ramps up, the application scenarios keep widening. Right now, these high-frequency filter chips are already working in 5G comms, satellite internet, IoT, and vehicle communications. Robotics is the next big growth frontier. Huang mentioned that robots today mostly rely on remote controls or pre-programmed routines. In the future, they’ll need to sense their environment in real time and interact autonomously. That shift means a massive explosion of wireless signal exchanges between robots and the world around them, which will drive huge demand for filter chips. The company’s next move is to gradually push its SAMES® sensor products into the automotive electronics and industrial inspection markets. This year’s revenue target: double last year’s figure.
Behind this wave of domestic core-component breakthroughs is the overall rise of the Greater Bay Area’s semiconductor ecosystem.
Huangpu District, Guangzhou’s core semiconductor hub, is gradually filling in the upstream gaps in the supply chain. Tang Qing, deputy section chief of the Electronic Equipment Division at the Huangpu District Industry and Information Technology Bureau, told NUPIAO that Guangdong has long been strong in end-device electronics, with a mature consumer-electronics chain. But a complete ecosystem can’t stop at the application end. Wafer manufacturing and other upstream choke points are where the real focus must be. Right now, places like Shanghai and Beijing already have a head start in those areas.
“We brought in CanSemi back in 2018—it became the first 12-inch wafer fab in the Greater Bay Area to reach mass production, filling a gap in Guangzhou’s chip manufacturing. As the core of the chain, a wafer fab’s arrival can effectively pull in chip design, materials, and equipment players. Here in the district, we’ve already got an ecosystem covering IoT, RF chips, photomasks, inspection equipment, and packaging materials—companies like Smarter Micro, for example. Every link in the chain starts to feed into the next: design companies’ orders help wafer fabs ramp up, and the fab’s demand pulls in materials and equipment.” Tang said.
As the regional hub for wafer manufacturing, CanSemi’s capacity expansion and process upgrades are giving local chip companies stronger manufacturing support. CanSemi now has two 12-inch wafer fabs—the first one (Phases 1 and 2) and the second (Phase 3). By the end of last year, monthly capacity hit 63,300 wafers. They’ve already kicked off construction of a third fab (Phase 4), a dedicated production line for mixed-signal ICs with a planned capacity of 40,000 wafers per month. Once Phase 4 is up, total capacity will jump to 120,000 wafers per month.
Wu Hao, assistant president of CanSemi, shared with NUPIAO that the rapid growth of AI and the digital economy is generating a tsunami of data computing and storage demand, which puts much higher requirements on data transfer speeds and energy efficiency. To catch that trend, CanSemi is adding a silicon photonics chip line in Phase 4. They plan to extend their current 180nm to 55nm process nodes toward more advanced nodes, build up mixed-signal chip manufacturing capabilities, and set up a specialty line centered on optical chips and optoelectronic integration to meet the GBA’s demand in mixed-signal and optoelectronic compute-in-memory chips.
The GBA’s semiconductor cluster is also weaving a collaborative network that links upstream and downstream. Dr. Yi Xinyan told us that on the supply side, with the local government connecting the dots, the company has already partnered with a photomask manufacturer right in Huangpu District. They’re also sourcing core materials locally—specialty gases and key metal materials for semiconductors all come from Guangdong-based suppliers. “Chip manufacturing has become a typical area driven by policy. On the investment and financing side, the policy support is very strong, too.”
Huang Hongjun added that as an asset-heavy chip company, AiFo has already poured over 2 billion yuan into fixed assets. The capital needs are massive. The company’s growth has benefited hugely from government industrial policy guidance and investment from industry funds; government backing makes up a big chunk of their funding. Plus, Guangzhou’s vibrant financial environment has been a huge help—banks have offered very favorable loan terms, durations, and interest rates.
Even though industry collaboration and policy support are starting to form a combined force, structural weaknesses in Guangdong’s semiconductor supply chain are still glaringly obvious. Dr. Yi admitted that the short board remains in upstream materials and equipment manufacturing. Local equipment suppliers are still too thin on the ground, and some equipment still has to be brought in from the Yangtze River Delta. This is a gap that urgently needs to be filled.
