Reliability test on chip type of high capacitance multilayer ceramic capcitors : KENJI MURATA and TOSHIMA KAWAKAMI. Proceedings of the 24th Symposium on Reliability and Maintainability, Tokyo, Japan, 19 (6–8 July 1994)

Abstract

Microelectronic devices, such as transistors, capacitors, and resistors, within an active chip, require some protection from the environment, as well as both electrical and mechanical connections to the surrounding components. Electronic packaging is the science of placing electronic devices and circuitry in protective enclosures and providing interconnections within and between different electronic devices. Electronic devices have been packaged in a variety of ways. One of the first methods was a kovar (high nickel alloy) preformed package. The device was bonded to the bottom, and the top was later secured. Ceramic packages, similar in construction to the Kovar casing, later appeared as a cheaper alternative. The first evidence of plastic encapsulation was seen in the early 1950s, using compression molding of phenolics. The phenolic material was compressed around electrical devices leaving the electrical connectors sticking out. The problem with this method was that the delicate connections were often severed due to the high pressure. By the early 1960s, plastic encapsulation emerged as an inexpensive, simple alternative to ceramics and metal encasing and during the 1970s virtually all high-volume integrated circuits (ICs) were encapsulated in plastic. As of 2015, plastic encapsulation is used in most devices in both consumer electronics as well as high reliability applications. A plastic-encapsulated microcircuit (PEM), often called a plastic package, consists of an integrated circuit chip physically attached to a leadframe, and/or signal traces on the substrate, forming an electrical connection to the I/O leads or interconnects, and encapsulated, forming a direct contact with the chip, leadframe, and interconnects. PEMs are made in either surface-mount or through-hole configurations.