ChipMOS Brand Guidelines: A 1997 Mosel–Siliconware Venture & Display-Driver Packaging

A joint venture of two chip companies.

ChipMOS — written with a capital M, O and S, and known in Chinese as 南茂科技 — is a Taiwanese company that assembles and tests chips designed or made by other firms, a business the industry calls outsourced semiconductor assembly and test. Its annual report to the US Securities and Exchange Commission for 2022 says the company was incorporated on 28 July 1997 as “a joint venture company between Mosel Vitelic Inc. and Siliconware Precision Industries Co., Ltd.,” with other investors taking part.

The company’s own list of milestones says ground was broken for a test plant in Hsinchu and an assembly plant in Tainan in the year of its founding. The test plant opened in March 1998 and the Tainan assembly plant in October 1998. In July 1999, it says, it bought the Kaohsiung plant of the American chip maker Microchip and set up a Kaohsiung branch.

For much of its history ChipMOS had a holding company above it. The company says its parent, ChipMOS Bermuda, listed on Nasdaq in June 2001, and that in September 2007 a share exchange made the Taiwanese company a wholly owned subsidiary of the Bermuda parent. The Taiwanese company joined the main board of the Taiwan Stock Exchange on 11 April 2014, according to the 2022 annual report. On 21 January 2016 the two signed a merger agreement; the Bermuda parent merged into the Taiwanese company, which survived, on 31 October 2016, and its American depositary shares began trading on Nasdaq on 1 November 2016 under the symbol IMOS. ChipMOS is headquartered in the Hsinchu Science Park.

It also had a mainland Chinese arm. The company says it opened an assembly and test plant in the Qingpu industrial park in Shanghai in November 2005. Its 2022 annual report says that on 30 November 2016 it agreed with Tsinghua Unigroup to form a joint venture, selling 54.98% of the Shanghai company to strategic investors; the deal was completed in March 2017, after which the Shanghai company was no longer a subsidiary. The Taipei Times reported in August 2017 that the Shanghai venture was then 45% owned by ChipMOS.

Testing in Hsinchu, assembly in Tainan.

ChipMOS divides its work between two science parks. Its 2022 annual report says testing is done mainly at facilities in the Hsinchu Science Park and the Hsinchu Industrial Park, and that all assembly is done at a facility in the Southern Taiwan Science Park in Tainan: “Our production facilities are located in Hsinchu and Tainan, Taiwan.” The company’s website adds that plants at Zhubei and Hukou in Hsinchu County provide wafer bumping and wafer testing.

Its services fall into a few groups, according to the same report: assembly and testing of memory chips, of logic and mixed-signal chips, and of display-panel driver chips for LCD, OLED and other screens, together with gold bumping. Bumping places tiny metal bumps on a finished wafer so that a chip can be joined face-down to a film or a glass panel. For display drivers ChipMOS offers chip-on-film and chip-on-glass assembly; its milestones date its first tape-carrier line for LCD drivers to April 2000 and the launch of chip-on-film packaging to January 2003. The company also says it made 12-inch gold bumping ready for volume production in December 2010 and wafer-level chip-scale packaging in November 2011.

Display drivers have become central to the business. The Taipei Times described ChipMOS in August 2017 as “the world’s second-largest LCD driver IC packaging and testing service provider,” and listed its customers as including Samsung Electronics and the Taiwanese driver-chip designers Novatek, Himax and Raydium. The same report said Micron Technology, a major memory customer, had been reducing orders for ChipMOS’s memory packaging since late 2016. In May 2023 the paper reported company data showing that display-driver packaging made up about 52.9% of revenue in the first quarter of that year, and memory testing and packaging about 15%.

In March 2026 the flat-panel maker Innolux said it had agreed to sell a panel-module assembly facility in Tainan to ChipMOS, the Taipei Times reported, adding that ChipMOS was seeking to expand capacity for memory and logic chips used in AI-related devices; completion of the purchase was not reported at the time.

The company has also absorbed other businesses along the way. Its milestones say it first invested in ThaiLin Semiconductor in December 2002 and completed a merger with ThaiLin in June 2015, with ChipMOS as the surviving company.

Design and documentation.

Chip packaging and test companies sit between the chipmaker and the finished device. The trade calls them OSATs, for outsourced semiconductor assembly and test: they take silicon made by others, mount it, connect it, seal it and check that it works. Their customers are other technology companies, so they rarely speak to the public, and their imagery is built for engineers, buyers and investors.

That imagery leans on close-ups. Company pages and annual reports return again and again to macro shots of packaged chips and the substrates beneath them, to fine arcs of gold or copper wire bonds linking a die to its frame, and to wafers catching the light. Methods carry the names that a consumer brand would give to products: flip chip, fan-out, system in package, 2.5D and chiplet packaging.

The second register is the factory. Rows of test handlers, operators in white cleanroom suits, and long, low factory campuses in places such as Kaohsiung, Penang and Jiangsu stand for scale and reliability. Plants are often known by codes and numbers rather than names, and maps of sites across Asia, Europe and the Americas do much of the storytelling. Trade shows such as SEMICON are where these companies meet their customers face to face.

This guide sets out what can be checked about each company — who founded it, who owns it, where it works and what its record shows — and marks clearly what rests only on the company’s own word. The palettes and type here are our own interpretation, not the companies’ marks.

Capital letters inside the name.

The name itself carries a technical echo: MOS is the usual abbreviation for metal-oxide-semiconductor, the transistor structure behind most modern chips, and the company sets those three letters in capitals within its name. ChipMOS uses the same spelling in English, in its Nasdaq listing and on its Chinese-language website.

Its dual listing obliges ChipMOS to file detailed annual reports in the United States as well as in Taiwan. Those filings give its founding date, its parents, its listings and where its work is done. The Taipei Times has reported on its business, describing it in 2023 as “a tester and packager of driver ICs and memory chips.” Claims about awards, certifications and firsts on its website are the company’s own.

For a design guide, ChipMOS shows how a company whose products are never seen by end users still builds an identity — in its case, around a name that spells out its technical field. Compare Powertech Technology, another Taiwanese assembly and test house, and TSMC, the Hsinchu foundry whose science park ChipMOS shares. For this guide we use a harbour navy and a bump gold with a sans, an unofficial interpretation; no product or logo is reproduced.

Keep ChipMOS’s identity on hand — save it to a board in the Made Good inspiration library.