LQFP

Low-profile Quad Flat Package (LQFP) is a type of surface-mount integrated circuit package characterized by a rectangular body with leads placed on all four sides. The leads extend outward from the sides in a gull-wing shape and then bend down to form contact pads on the underside, enabling a high pin count in a compact footprint. LQFPs are offered in a range of body sizes and lead pitches, with pin counts commonly from 32 to 256 and lead pitches typically between 0.4 and 0.8 millimeters. The overall height is low compared with many other packages, which justifies the “low-profile” designation.

Construction and variants commonly use a plastic molding compound with a leadframe and epoxy resin encapsulation. Body sizes may range from roughly 7 by 7 millimeters up to about 25 by 25 millimeters, depending on pin count. Some variants include a central thermal pad beneath the package to improve heat dissipation, though many LQFP devices do not include an exposed pad. LQFP is related to other quad-flat families such as TQFP (Thin Quad Flat Package) and PQFP (Plastic Quad Flat Pack); the primary distinctions are height and sometimes lead geometry.

Applications and manufacturing notes: LQFP is widely used for microcontrollers, memory devices, DSPs, and other integrated circuits that require a high I/O count in a compact package. It is compatible with standard surface-mount assembly processes and reflow soldering. Designers typically follow vendor-specific land-pattern guidelines to ensure reliable solder joints and minimize bridging at fine pitches.

Advantages of LQFP include a high pin count in a relatively small footprint and suitability for automated assembly. Limitations can include solder-bridging risk at very fine pitches and larger lead-frame surface area compared with some other package types.