ChipMOS Technologies: how a 1997 Taiwan semiconductor venture became a global OSAT supplier
A semiconductor does not leave a wafer fabrication plant ready to be installed in a smartphone, vehicle, monitor or server.
Before a finished chip can enter an electronic product, individual dies need to be separated, packaged, connected and tested. Display-driver chips require their own specialised processes. Memory devices must be tested under demanding conditions. Increasingly complex packages require technologies such as wafer bumping, redistribution and wafer-level packaging.
That largely invisible part of the semiconductor industry is where ChipMOS Technologies has built its business.
ChipMOS was incorporated in Taiwan on 28 July 1997. Its history is more specific than simply describing it as a company that later “moved into” semiconductor assembly and testing.
ChipMOS was created for semiconductor back-end manufacturing from the beginning.
The company’s regulatory filings describe the original ChipMOS Technologies Inc. as a joint venture between Mosel Vitelic Inc. and Siliconware Precision Industries, with participation from other investors. ChipMOS’s own corporate history additionally records that Mosel’s back-end factory operations were spun off into the newly created company.
Those two facts together provide the clearest picture of its origin: ChipMOS emerged from existing Mosel Vitelic back-end operations while being established as a separate joint-venture company involving Mosel, Siliconware Precision and other investors.
Nearly three decades later, ChipMOS remains focused on the same broad stage of semiconductor production, although the technologies, markets and corporate structure surrounding that work have changed considerably.
A factory operation became a standalone semiconductor company
ChipMOS’s first year was not the story of a software start-up searching for a business model.
The company entered an established industrial process.
ChipMOS says the Mosel back-end factory was spun off into ChipMOS Technologies in July 1997. Regulatory filings state that the new company was incorporated under Taiwanese law as a joint venture between Mosel Vitelic and Siliconware Precision.
Construction and expansion started almost immediately.
The company broke ground on additional testing and assembly buildings during 1997. Its Hsinchu operation obtained ISO 9002 and ISO 14001 certifications during the same year.
In 1998, ChipMOS completed a new testing building and later completed a new assembly building that began operating in October.
The following year it expanded again by acquiring Microchip Technology’s Taiwan operation in Kaohsiung and establishing a branch there. ChipMOS also started mixed-signal product and mBGA packaging services and added chip-scale packaging capabilities during 1999.
These early investments reveal what ChipMOS was designed to do from the outset: provide specialised manufacturing services after semiconductor wafers had been fabricated.
What an OSAT company actually does
ChipMOS operates in the outsourced semiconductor assembly and test industry, normally shortened to OSAT.
The distinction between wafer fabrication and back-end processing is important.
A foundry manufactures semiconductor circuitry on wafers. But those wafers still contain many individual dies and require additional processing before the chips can be integrated into finished products.
Back-end semiconductor companies can perform services including wafer probing, bumping, assembly, packaging and final testing.
Testing determines whether a semiconductor operates within its required specifications.
Assembly and packaging protect the semiconductor die and create the electrical connections needed to integrate the chip into a larger system.
ChipMOS currently provides services across memory semiconductors, display-driver semiconductors and logic or mixed-signal products. Its services include semiconductor testing, package assembly and bumping technologies.
Its customers include fabless semiconductor companies, integrated device manufacturers and semiconductor foundries rather than ordinary retail consumers.
That is why consumers can use products containing chips processed by an OSAT company without ever seeing the ChipMOS name.
Display drivers became an important speciality
One of the most important developments in ChipMOS’s early history arrived in 2000.
The company began TCP packaging for LCD driver semiconductors in April that year and started 12-inch wafer assembly and testing in November.
Display-driver integrated circuits perform a specialised but essential job.
They translate digital image information into the electrical signals required to control pixels in a display panel.
As flat-panel displays spread through notebooks, monitors, televisions, smartphones and eventually vehicles, display-driver semiconductor manufacturing developed into a significant specialised market.
ChipMOS continued investing in this area and today identifies LCD, OLED, automotive-panel and other display-driver semiconductor testing and assembly among its principal capabilities.
The company has also built substantial experience in memory semiconductor testing and packaging.
That combination of memory, display-driver and mixed-signal work remains central to the modern ChipMOS business.
ChipMOS reached Nasdaq through a more complicated corporate structure
ChipMOS’s public-market history requires careful wording because the company that trades today is not the result of one simple listing event.
ChipMOS’s official timeline records that the group became the first Taiwanese semiconductor testing and packaging company to be listed on the Nasdaq Stock Market in June 2001.
The US-listed entity involved at that stage was ChipMOS Technologies (Bermuda) Ltd., which had been incorporated in Bermuda in 2000 as part of a corporate restructuring.
ChipMOS Taiwan remained the operating company.
During subsequent restructuring, ChipMOS Bermuda acquired substantial ownership of ChipMOS Taiwan, and in September 2007 ChipMOS Taiwan became a wholly owned subsidiary of ChipMOS Bermuda through a share-exchange transaction.
That structure eventually changed again.
ChipMOS Taiwan listed its shares on the Taiwan Stock Exchange in April 2014 under ticker 8150.
The group then undertook another major simplification in 2016.
The 2016 merger put the Taiwan company at the centre
In January 2016, ChipMOS Bermuda and ChipMOS Taiwan announced an agreement under which the Bermuda parent would merge into the Taiwan company.
ChipMOS Taiwan would survive.
The companies said the restructuring was intended to simplify the group structure, reduce operating costs and create a more efficient corporate arrangement.
Shareholders approved the deal later that year.
The merger closed on 31 October 2016.
The old ChipMOS Bermuda shares stopped trading, while newly issued American Depositary Shares representing ChipMOS Taiwan began trading on Nasdaq under the familiar IMOS ticker on 1 November 2016.
ChipMOS Taiwan’s ordinary shares continued trading on the Taiwan Stock Exchange under 8150.
This distinction remains useful in 2026.
ChipMOS Technologies Inc. is a Taiwan-incorporated company listed on the Taiwan Stock Exchange, while American investors can access it through Nasdaq-listed ADSs under IMOS.
Expansion added factories, acquisitions and new packaging technologies
ChipMOS did not build its manufacturing footprint through organic expansion alone.
Its corporate timeline records multiple acquisitions, investments and integrations.
In 2002, the company invested in Chantek Electronic and ThaiLin Semiconductor.
In 2003, it invested in Advanced Micro Chip Technology and launched reel-to-reel chip-on-film assembly and testing services.
During 2004, ChipMOS integrated Advanced Micro Chip Technology’s operations and purchased testing and assembly assets from FICTA.
Chantek was subsequently merged into ChipMOS Taiwan in 2005, while ChipMOS Logic merged with ThaiLin.
In 2010, ChipMOS acquired memory-testing and display-driver IC assets from Siliconware Precision. Siliconware Precision also became a strategic shareholder.
The following year, ChipMOS established production capability for technologies including 12-inch gold bumping, copper pillar and wafer-level chip-scale packaging.
These were not departures from the company’s original industry.
They represented deeper specialisation within semiconductor back-end manufacturing.
Bumping helped move packaging closer to the wafer
Traditional semiconductor packaging can make the assembly process seem as though it begins only after individual chips are cut from a wafer.
Modern packaging is more complicated.
Bumping creates small conductive structures that help connect semiconductor dies to packages, substrates or other components.
ChipMOS lists bumping as one of its major service categories alongside assembly and testing.
Its capabilities developed to include technologies such as gold bumping, copper pillar processes, redistribution-related processes and wafer-level packaging.
These technologies became increasingly relevant as semiconductor packages grew denser and electronic devices demanded greater functionality within limited physical space.
ChipMOS’s role therefore expanded technologically without fundamentally changing its position in the supply chain.
It remained a back-end semiconductor manufacturer, but the back end itself became more technically sophisticated.
China expansion was followed by a change in ownership structure
ChipMOS also expanded manufacturing activities into mainland China.
The company began construction of testing and assembly facilities in Shanghai in 2002 and held the grand opening of its Shanghai facility in 2005.
A later restructuring changed the ownership of that business.
ChipMOS agreed with Tsinghua Unigroup in 2016 to form a joint venture involving the Shanghai operation. Under the announced transaction, a Tsinghua Unigroup-led investor group would acquire a majority interest while ChipMOS retained a minority stake.
ChipMOS’s corporate timeline records that it disposed of its remaining equity interest in Unimos in December 2023.
Its current corporate descriptions focus its manufacturing footprint on facilities in Taiwan, including operations in Hsinchu Science Park, Hsinchu Industrial Park and Southern Taiwan Science Park.
That makes it misleading to describe the historical Shanghai operation as though it remains a wholly owned current ChipMOS factory.
Taiwan remains the centre of the modern company
ChipMOS’s current manufacturing identity is firmly rooted in Taiwan.
The company operates semiconductor back-end facilities covering testing, assembly and bumping processes.
In May 2024, ChipMOS recorded another manufacturing milestone when it procured a third factory in the Tainan Science Park area.
The company has continued investing in capacity as demand has changed across its memory and display-related businesses.
Importantly, capacity announcements should not automatically be treated as proof of future financial performance.
Semiconductor assembly and testing is capital intensive, and demand can change with memory pricing, consumer-electronics cycles, automotive production, display demand and customer inventory adjustments.
For that reason, actual reported revenue provides a more useful measure of what has already happened than forecasts about what new capacity might eventually produce.
2025 revenue reached NT$23.9 billion
For the year ended 31 December 2025, ChipMOS reported consolidated revenue of NT$23.93 billion, equivalent to approximately US$762.9 million using the exchange rate applied in its results announcement.
That represented an increase of 5.5% from NT$22.70 billion in 2024.
Fourth-quarter 2025 revenue reached NT$6.52 billion, up 20.8% from the comparable quarter in 2024.
These numbers provide useful context for the company’s size.
ChipMOS is an established public semiconductor manufacturer with hundreds of millions of US dollars in annual revenue, but it should not be confused with the enormous semiconductor foundries that manufacture leading-edge wafers or with chip designers whose brands appear directly in consumer products.
Its economic role is different.
2026 brought substantially higher reported revenue
ChipMOS’s reported revenue accelerated further during 2026.
Second-quarter revenue reached NT$7.383 billion, or approximately US$231.8 million at the exchange rate used by the company.
That was 6.5% higher than the first quarter of 2026 and 28.7% higher than the second quarter of 2025.
ChipMOS said the quarter represented its highest quarterly revenue level since 2014.
July then produced another company-reported record since 2014, with monthly revenue of NT$2.823 billion, 43.6% higher than July 2025.
August revenue was NT$2.786 billion, down 1.3% from July but 33.3% higher than August 2025.
ChipMOS has attributed part of this strength to memory demand associated with AI and data-centre applications.
That explanation should be presented as the company’s assessment, rather than as proof that every increase in ChipMOS revenue is directly caused by artificial intelligence.
The reported revenue figures themselves are historical results. Explanations about market demand and future capacity requirements remain management commentary.
AI changes demand, not ChipMOS’s basic identity
Artificial intelligence is affecting semiconductor supply chains well beyond the companies designing GPUs and AI accelerators.
Large computing systems also require memory, networking silicon, power electronics, displays and other semiconductor components.
ChipMOS has said stronger memory demand related to AI applications has contributed to recent business conditions.
But this does not make ChipMOS an “AI company.”
It remains an outsourced semiconductor assembly and testing company.
AI-related infrastructure represents an end-market demand driver for parts of its existing manufacturing business rather than a wholesale change in what the company does.
That distinction matters because technology companies can easily be described too broadly when a powerful new market trend appears.
ChipMOS does not design large language models, sell AI software or manufacture AI accelerators under its own brand.
It provides back-end manufacturing services to semiconductor companies.
A 1997 business that still occupies the same critical layer
ChipMOS has changed significantly since 1997.
Its manufacturing technologies have advanced.
Its facilities have expanded and changed.
It has acquired businesses, integrated subsidiaries, entered and restructured operations in China and reorganised its public-company structure.
Its shares have moved through a complicated path involving a Bermuda parent, a Taiwan listing, a merger and Nasdaq-listed ADSs.
Yet the central business has shown unusual continuity.
ChipMOS began as a semiconductor back-end manufacturing company.
It remains one.
The difference is that modern semiconductor back-end manufacturing involves technologies and tolerances far beyond those of the late 1990s.
Memory devices have become denser. Displays have moved from conventional LCD panels into higher-resolution, OLED and automotive applications. Semiconductor packages have become more complex. Wafer-level processes and advanced interconnection technologies have become increasingly important.
ChipMOS has followed those changes without needing to invent an entirely different corporate identity.
As of September 2026, the company is listed on the Taiwan Stock Exchange under 8150 and its ADSs trade on Nasdaq under IMOS. It provides testing, assembly and bumping services from its Taiwan manufacturing operations to semiconductor companies serving global electronics markets.
Its history is therefore best understood not as a series of unrelated pivots, but as almost three decades of increasingly sophisticated work at one of the least visible but essential stages of semiconductor production.
Sources
This article was checked against ChipMOS Technologies’ official corporate history and milestone records, ChipMOS annual and regulatory filings with the US Securities and Exchange Commission, official documentation relating to the ChipMOS Bermuda restructuring and merger, and ChipMOS financial and monthly revenue announcements available through 18 September 2026.