A surface-mount package with gull-wing leads extending from all four sides. Its joints are easy to inspect visually, and it is widely used for microcontrollers and similar ICs.
Japanese name: QFP
QFP (quad flat package) appears in 6 practice questions across 3 topics, including Packaging and assembly, How to read datasheets, Advanced packaging (3D and chiplets).
Field: Packaging and assembly
QFP stands for quad flat package and is a type of lead-frame package. The die is mounted on a die pad, wire-bonded to the leads and covered with mold compound; the protruding leads are then trimmed and bent into a shape like a gull's wing. Lead pitches of about 0.4 to 0.8 mm are common, and pin counts range from a few dozen to several hundred. Variants are named by body thickness, such as LQFP at generally about 1.4 mm and TQFP at about 1.0 mm. It can be seen as an SOP, which has leads on two sides, extended to all four sides.
Because the lead tips and joints are visible, solder quality is easy to check by eye or with automated optical inspection, and hand repair or replacement is straightforward. The bent leads flex like springs and absorb thermal expansion mismatch, so solder joints tend to last longer under temperature cycling. On the other hand, terminals can be placed only around the perimeter, so the package grows as pin count rises. Narrower pitches make leads easier to bend, and controlling the height alignment of the lead tips (coplanarity) and solder bridging become problems.
In an ordinary QFP, heat from the die escapes mainly through the mold compound and the leads, so thermal resistance is relatively high. For higher-power products, versions with an exposed die pad on the underside soldered to the printed circuit board, or with a heat spreader built into the package, are used. Thermal vias under the exposed pad spread heat into inner-layer or back-side copper. In these versions, as with QFN, solder volume and voids at the pad must be controlled.
QFP uses more board area because its leads extend outward, and the lead length adds inductance, but its ease of inspection and handling has kept it in long use for microcontrollers and ICs for industrial equipment. QFN tucks the terminals under the package for a smaller, thinner part with good thermal and high-frequency performance. BGA places balls across the whole underside, providing far more terminals than a QFP of the same size, and is the mainstream for high-performance, high-pin-count chips. The choice weighs pin count, board area, heat dissipation, inspection method and board cost.
Answer: B. Pin 1 is next to the index mark, and numbers increase counterclockwise when viewed from the top
The top of the package has an index mark—a dimple, dot, notch or chamfer—and pin 1 is next to it. Pins 2, 3 and so on generally increase counterclockwise when viewed from the top. Always check whether the datasheet's pin diagram is a top view or a bottom view. In a bottom view, left and right appear reversed, and confusing the two leads to the mistake of a mirror-image footprint on the board. BGAs use numbers such as A1, with rows as letters and columns as numbers.
QFP brings leads out from four sides, so its joints are easy to inspect visually, but terminals can be placed only around the perimeter. BGA places solder balls across the whole underside, allowing many more terminals, but its joints are hidden and are inspected with X-ray.
QFP has gull-wing leads extending from its sides, while QFN has no leads and exposes terminals on its underside. QFN is smaller, thinner and better at dissipating heat; QFP joints are easier to inspect visually and to rework after assembly.
Mainly body thickness: LQFP generally refers to about 1.4 mm and TQFP to a thinner body of about 1.0 mm. Lead pitch and pin count vary by part, so check the package drawing.
Using the area rather than just the perimeter allows more terminals than a QFP of the same size, with shorter connections.
Which correctly describes a feature of BGA (ball grid array…Long leads on four sides describe a QFP, and a ball array describes a BGA.
Which correctly describes a feature of QFN (Quad Flat No-le…QFP and DIP are single-package formats.
What is the method called that mounts a memory package stac…Leads on four sides describe a QFP, and balls on the bottom describe a BGA.
Which surface-mount package has gull-wing leads coming out …BGA and QFP are common package types.
What is the technology called that mounts optical transceiv…As an Amazon Associate I earn from qualifying purchases.
BGA QFN (quad flat no-lead package) Interconnect via DRAM (dynamic random-access memory) CPO (co-packaged optics) Backgrinding CSP (chip-scale package) Dicing Die bonding Flip chip