Plastic packaging

The vast majority of electronic components are encapsulated in plastic. Cell phones, cameras, household appliances, cars and airplanes are full of plastic components. Only a few space and military applications seem to be resisting the invasion.

The main reason for using plastic encapsulation was to reduce costs, especially for production volumes in consumer applications. The major advances made in polymers and composites after the war prompted the first developments. After a few unsuccessful attempts in the early 1970s, plastic encapsulation processes became sufficiently reliable to meet the needs of industrial equipment, then gradually extended their field of application to the detriment of the hermetic ceramic or metal housings used since the origin of transistors and integrated circuits (see box).

Plastic packaging has constantly pushed back its intrinsic limitations (water permeability, coefficient of expansion, adhesion to metal and chips, electrical and thermal properties, reliability).

Before explaining the reasons behind these developments, and why plastic encapsulation has been imposed on virtually all components on the board, this document defines what an electronic component package is, its main constituents and how it is manufactured. The advantages and limitations of plastic housings compared to hermetic housings are then presented, along with solutions for improving and making this encapsulation method more reliable. Finally, the challenges facing modern electronic component housings are summarized.