Overview of MCU process changes: development paths under the tide of AI application and cost reduction

1. Mainstream MCU process nodes and representative products

1. 40nm and above: currently the absolute mainstream, eFlash economic node

• Applicable scenarios: home appliances, traditional industrial control, consumer electronics, basic automotive regulations
• Core limitations:eFlash embedded flash memoryThe most economical range is only above 40nm
• Representative manufacturers & products:
  • ST：STM32F1/F4（65/90nm）、STM32H5/H7（40nm）
  • Renesas：RA6M4、RX66T（40nm）

2. 28nm: standard for high-end MCUs, main node for automobiles and AIoT

• Drivers: high performance, low power consumption;MRAM/RRAM/PCMReplace eFlash to break through process bottlenecks
• Foundry focuses on production expansion direction, cost and performance balance point
• Representative manufacturers & products:
  • NXP：i.MX RT1170、MCX N、S32K
  • ST：Stellar P6 automotive MCU
  • Renesas：RH850/E2x, U2B, U2A series

3. 18nm / 16nm: The era of AI and high-end automotive computing power

• Applicable scenarios: client-side AI inference, smart cockpit, domain controller, high-performance real-time control
• Sources of demand: image/audio processing, massive vehicle data streams, multi-sensor fusion
• Representative manufacturers & products:
  • NXP：S32Z/S32E (TSMC 16nm FinFET)
  • Renesas：RL78/F, G23 series
  • ST：18nm FD-SOIA new generation of products (scheduled for production in 2025), equipped with ePCM, significantly improving density, energy efficiency and RF performance

2. Changes in the industrial chain brought about by process upgrades

1. Mature processes still account for more than 90% of shipments

   40/65/90nm has a complete ecosystem, stable delivery, and short development cycle, and continues to dominate massive markets such as home appliances and industrial control.
2. Advanced MCUs fully rely on foundries

   The in-house production lines of international MCU original manufacturers generally stop at 40nm, and all production lines below 28nm need to be outsourced:
   • TSMC, UMC, SMIC: 28nm/16nm main force
   • ST 18nm FD-SOI: withSamsungcooperative development
3. Production capacity is concentrated towards high-end products and competition intensifies

   NXP, Renesas, and ST are collectively betting below 28nm, and the high-end MCU market is rapidly involution.

3. Trends in localization and cost reduction: ST’s landing in China has become a landmark event

• ST × Hua Hong Semiconductor: The 40nm MCU will be manufactured by Huahong and will be put into production by the end of 2025.
• Core logic:
  1. satisfySupply chain security and localized supporting facilitiesrequest
  2. Close to China’s new energy vehicle market,Shorten response time
  3. Against the rise of the local MCU,Reduce costs and grab share

4. Summary of future paths

• stock market: Mature processes above 40nm are stable in the long term and focus onCost-effective and stable delivery
• incremental market:28nm becomesHigh-end MCU standard, rapid penetration of automobiles and AIoT
• frontier markets：18/16nm accompanyingDevice-side AI and domain controlExploded and became the technological commanding heights of leading manufacturers
• overall pattern: The process layering is clear,Domestic substitution + local manufacturing + extreme cost reductionThree lines are running in parallel, and opportunities are still concentrated in new tracks such as smart cars, edge computing, and industrial interconnection.