This is a term used when companies offer out a contract for the assembly of electronic components for other companies. It is known as ECM (Electronic Contract Manufacturing) and is a service often used by OEM companies; instead of the OEM Company having to manufacture complex components and motherboards themselves they outsource their manufacturing task to Electronic Component Manufacturing companies. ECM companies do not brand their components in any way at all; instead the components remain un-branded and gain the name of the OEM Company that offered out the contract.
It was in 1981 when IBM entered the computer market that the CM (Contract Manufacturing) Industry was born. IBM started a trend by outsourcing certain jobs, they classed this as outside core competence and this in turn sparked a trend of contracts being outsourced which gave ECM companies a method of increasing economies of scale. In time the market power shifted from OEMs to larger ECMs, this was largely in part too many OEMs selling off all of their old production units to Electronic Contract Manufacturers. An example of this was a Swedish company that specialised in telecommunications (Ericsson) and they sold seven plants to ECM companies Solectron and Flextronics in 1997.
There are a lot of ECM companies today with the leading (key) companies being: Foxconn, Jabil Circuit, Solectron, Benchmark Electronics, Flextronics, EE Technologies, Tresmine, Celestica and Sanmina-SCI. Some of the above companies are operated from Taiwan and North America. There are other companies that offer these services however all of the above are trusted well established ECMs