Plessey Semiconductors

  • Established 2009 (earlier company started in 1957)
  • Head Office Plymouth
  • Employees 140
  • Plessey ownership
    Ownership: Venture capital companies, Michael LeGoff
  • 2018 Sales £20m

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The long journey to creating a force in semiconductors

The evolution of Plessey Semiconductors goes back almost a century, during which there have been many twists and turns in the story of what was once a mighty UK manufacturer.

  • Plessey starts in London as a mechanical engineering company
  • Plymouth plant built
  • GEC of the UK and Germany’s Siemens acquire Plessey, valuing company at £1.75bn, and split the operations, with GEC taking semiconductors including plants in Plymouth and Lincoln
  • Michael LeGoff founds Dynex in Canada , a distributor of power semiconductors, used in mobile phones
  • GEC-Plessey Semiconductor acquired by Mitel of Canada
  • LeGoff’s Dynex buys Lincoln semiconductor plant from Mitel
  • X-Fab of Germany buys the Plymouth plant
  • LeGoff leaves Dynex, which is sold to CSR of China in 2006
  • LeGoff buys the Plessey semiconductor assets in Swindon
  • LeGoff buys Plessey’s Plymouth plant and bases the company there. The Swindon operation closes
  • Plessey announces a £60m expansion, based on new venture capital investment and a £30m loan from Deutsche Bank
  • LeGoff leaves Plessey which embarks on new strategy based on “microLEDs”

Britain’s unhappy history in electronics production

Britain has a proud record of innovations in electronics – but has done a poor job of turning these into sustainable businesses that create large numbers of jobs.

After World War Two, UK engineers built some of the world’s first electronic computers, among them Cambridge University’s EDSAC machine (electronic delay storage automatic calculator) which was completed in 1949.

In the 1970s, the UK was responsible for three of the world’s leading electronics companies: Plessey, GEC and the computer manufacturer ICL. In the 1980s, Ferranti, another pioneering UK firm, was responsible for a number of innovations including so-called gate-array chips – a form of “customised” or “application-specific” semiconductor.

Now that these one-time electronics leaders have all disappeared, UK electronics manufacturing is represented mainly by a few sophisticated companies turning out mainly small quantities of high-value products on behalf of bigger businesses on an “outsourcing” basis.

Such “contract manufacturers” include Briton and Paragon, both based in Bedford, and US-owned Plexus, which operates a plant in Bathgate, Scotland. Such companies make products such as medical devices or control equipment, normally sold under other companies’ brands.

Besides Plessey, Britain is home to a handful of other semiconductor manufacturers. One of the few UK-owned businesses is Semefab, based in Glenrothes, Scotland. Infineon of Germany operates a plant at Newport in South Wales, while NXP of the Netherlands makes chips in Stockport, near Manchester.

The area in and around Cambridge has a notable “cluster” of small electronics businesses, many with links to Cambridge University. Bristol and nearby towns are home to about 30 electronics firms – many of which were set up or staffed by skilled engineers and technicians who at one time worked for Inmos, a state-owned semiconductor business started in the city in 1978.

Inmos was responsible for a number of technology successes – including the “transputer” microprocessor. But it failed to meet its commercial targets and was privatised in 1984, disappearing from view a few years later.