ABSTRACT
This technique, when used on standard circuit board materials, is known as chip on board (COB). The die is considered right-side up, or "face" up, when its contact pads face up from the substrate.
In the 1980s and 1990s, a number of 1C assembly technologie-s were developed to utilize either bare die or very small packages that approximated the size of bare die. Flip chips use the same bare die as COB, but the bond pads are placed toward the board, or face down. Also placed face down are chip-scale packages (CSPs), which are die enclosed in a package that is no more than 120% of the bare die x-y dimensions. All of these die-size components are responses to the increasing demands for higher density, higher-speed performance, and increased functionality.
