The housing that integrated circuits (chips) are placed in. The package is then either plugged into (socket mount) or soldered onto (surface mount) the printed circuit board. Creating a mounting for a chip might seem trivial, but chip packaging is a complicated industry. Being able to provide more interconnections to a bare chip (bare die) that is increasingly shrinking in size is an ever-present problem. In addition, smaller package sizes allow more chips to be placed inside phones and other handheld devices. See BGA
, package on package
Empty Chip Package
Packages are empty vessels into which the bare chip is placed. Tiny wires connect the leads on the package with the leads on the chip.
This bare microcontroller chip from Microchip is approximately 4x5mm. It is mounted in this special glass package to show how wires are bonded from a chip to the package leads.
They Don't Get Much Smaller
These microcontrollers from Microchip are about as small as they come, and the packages are downright minuscule. See microcontroller