Topic summary
CQFP
Extracted from the Wikipedia article Quad flat package.
CQFP packages
Hereby the leads are soldered on top of the package. The package is a multilayer package, and is offered as HTCC (high temperature co-fired ceramic). The number of bonding decks can be one, two or three. Package is finished with a nickel plus a thick gold layer, except where the leads are soldered and decoupling capacitors are soldered on top of the package. These packages are hermetic. Two methods are used in order to make the hermetic sealing: eutectic gold-tin alloy (melting point 280 °C) or seam welding. Seam welding gives rise to significantly less temperature rise in the internal of the package (e.g., the die attach). This package is the main package used for Space projects.