Company at a glance
Scale
Revenue up 115% since FY2023
Growth prospects
Expanding customer base and product roadmap
via biz.ifeng.com ↗Achieved 28nm wafer bumping volume production in early 2016 on China's first 12-inch high-end chip bumping linevia cls.cn ↗STAR Market IPO accepted October 30, 2025, raising a planned RMB 4.8bn for 3D multi-die integration packaging and ultra-high-density interconnect pro…China competition
Competes with JCET, Tongfu Microelectronics, Huatian, SMIC ecosystem in Advanced packaging — peers listed at sector level.
SubstituteGlobal comparables
Global reference set: TSMC, ASE, Amkor.
ASE Group and Amkor (OSAT advanced packaging)Technical gap
Sector rated substitute vs the frontier.
Obstacles
US export-control exposure
via tclegal.cn ↗Added to the US Commerce Department Entity List on December 18, 2020; US suppliers require licenses to ship to itAll sourced facts (10)
- Listing status: Shanghai Stock Exchange (STAR Market) · 688820 · A share
- Identity: SJ Semiconductor Co., Ltd. = 盛合晶微半导体（江阴）有限公司, formerly 中芯长电半导体有限公司, headquartered in Jiangyin, Jiangsu via sjsemi.com ↗
- Founding: Registered November 2014 after SMIC and JCET announced the 12-inch bumping and wafer testing joint venture in August 2014 via finance.sina.com.cn ↗
- First 12-inch bumping line: Achieved 28nm wafer bumping volume production in early 2016 on China's first 12-inch high-end chip bumping line via biz.ifeng.com ↗
- Entity List: Added to the US Commerce Department Entity List on December 18, 2020; US suppliers require licenses to ship to it via tclegal.cn ↗
- GlobalFoundries case: GlobalFoundries paid a US$500,000 penalty in November 2024 for shipping wafers to SJ Semiconductor without an export license via eet-china.com ↗
- IPO status: STAR Market IPO accepted October 30, 2025, raising a planned RMB 4.8bn for 3D multi-die integration packaging and ultra-high-density interconnect projects; passed listing committee review in February 2026 via cls.cn ↗
- Ranking: Gartner 2024: world's tenth-largest and mainland China's fourth-largest OSAT; 2022-2024 revenue CAGR of 69.77% ranked first among global top-ten OSATs via cls.cn ↗
- Customer concentration: Top-five customers contributed 72.83%, 87.97%, 89.48% and 90.87% of revenue across 2022-H1 2025; the largest customer reached 74.40% of H1 2025 revenue; Qualcomm was its first customer via cls.cn ↗
- Funding history: Series A 2015 (SMIC, Qualcomm Ventures, Big Fund); Series C US$300mm in 2021; C+ round US$340mm signed April 2023; US$700mm raised December 2024 (investors including Xin Guolian, Foteng Capital and Legend Capital) via cls.cn ↗
About
Foundry-style middle-end services: 12-inch wafer bumping and re-distribution, wafer-level packaging, and 2.5D/3D chiplet multi-die integration packaging on a build-to-order basis for fabless and IDM customers.
Ticker 688820
Why it matters
It operates China's first domestic 12-inch high-end bumping production line (28nm bumping in volume output since early 2016) and has become the growth leader among global top-ten OSATs (2022-2024 revenue CAGR 69.77%), but it has been on the US Entity List since December 18, 2020, making it a test case for sanctioned advanced packaging.
Where it sits in the stack
Advanced packaging
2.5D/3D integration, interposers, HBM attach, thermal management, substrate supply, and yield.
Assembly & test (OSAT)
High-end package complexity, global customer mix, test equipment access, and advanced substrate supply.
Key semiconductor products
- 12-inch mid-end wafer processinghigh-density bumping and re-distribution layer (RDL)
- Wafer-level packaging·WLP
- Chiplet multi-die integration packaging (2.5D/3D; H1 2025 mix·202556.24% chiplet integration, 31.32% mid-end processing, 12.44% WLP)
Financials
688820.SS · Shanghai Stock Exchange STAR Market 688820.SS · via Yahoo Finance ↗
Financial trajectory via annual filings via Yahoo Finance
RMB billionsMarket data refreshed daily; annual figures from exchange filings. Figures in the reporting currency shown on the chart.
Ecosystem
Global peer set
- ASE Group and Amkor (OSAT advanced packaging)
- JCET (长电科技) and TFME (通富微电) in mainland China
- TSMC CoWoS-type foundry packaging services
Competitive position
- China's earliest 12-inch middle-end foundry services provider, operating to front-end fab standards
- World No.10 OSAT by revenue for 2024 per Gartner, with the fastest 2022-2024 growth among the global top ten
- Chairman and CEO Cui Dong is a former SMIC executive vice president; company has no controlling shareholder
- No fab, customer, or qualification progress captured.
- Global comparables: ASE Group and Amkor (OSAT advanced packaging)
- Global comparables: JCET (长电科技) and TFME (通富微电) in mainland China
- Global comparables: TSMC CoWoS-type foundry packaging services
Milestones and signals
- 2025—Valuation Reported In IPO Coverage: CNY 约200亿
- 2025—Planned IPO Raise: CNY 48亿
- 2026-10-04—Market cap: RMB 216B
- FY2025—Revenue: RMB 6.5B
- Listing—Shanghai Stock Exchange (STAR Market) · 688820 · A share
What to watch
- Completion and pricing of the RMB 4.8bn STAR IPO
- Customer concentration risk with the top customer at about three-quarters of revenue
- Operating under Entity List constraints after the 2021 SMIC exit and renaming
- Capacity ramp of 3D multi-die integration lines funded by the December 2024 US$700mm round
Questions
Last reviewed 2026-07-11Answered questions
What is the measurable gap versus global reference companies?
China's earliest 12-inch middle-end foundry services provider, operating to front-end fab standards.
Open questions
- Which products are qualified beyond pilots in other?
- Which customers, fabs, or end markets show real adoption rather than policy interest?