Quad flat package

A quad flat package (QFP) is a surface-mounted integrated circuit package with "gull wing" leads extending from each of the four sides. Socketing such packages is rare and through-hole mounting is not possible. Versions ranging from 32 to 304 pins with a pitch ranging from 0.4 to 1.0 mm are common. Other special variants include low-profile QFP (LQFP) and thin QFP (TQFP).

The first QFPs were introduced in Japan in 1977 in order to provide more pins on a small package to allow a greater number of digits on electronic calculators. It soon spread to other consumer electronics in that country. The QPF only became common in Europe and United States during the early nineties. It is often mixed with hole mounted, and sometimes socketed, components on the same printed circuit board (PCB).

A package related to QFP is plastic leaded chip carrier (PLCC) which is similar but has pins with larger pitch, 1.27 mm (or 1/20 inch), curved up underneath a thicker body to simplify socketing (soldering is also possible). It is commonly used for NOR flash memories and other programmable components.