LQFP-48 7×7 mm Footprint: DFM, Layout, and Assembly Guide

LQFP-48 7×7 mm is a gull wing package used for surface mount assembly, also seen labeled 48-LQFP, 7 mm square QFP, 0.5 mm-pitch QFP. A dependable footprint follows the exact orderable-device drawing rather than the family name: nominal body 7.0 × 7.0 mm nominal, overall span About 9.0 mm including leads, seated height Typically 1.4–1.6 mm, pitch 0.5 mm, pin count 48; 12 per side, and exposed pad None on standard LQFP.

Use a 7 mm body, 0.5 mm pitch, and correct lead span; LQFP-48 also exists in other body sizes.

Typical uses include microcontrollers, USB devices, mixed-signal control. LQFP-48 is available in multiple body/pitch combinations; this page covers the common 7 × 7 mm, 0.5 mm-pitch form.

• Twelve fine-pitch leads per side fit 48 pins around a compact body, so routing channels and solder-mask registration must be proven early.
• Gull-wing package names cover families of drawings; body width, lead span, lead length, and seated height must all match the orderable part.

Place one local decoupler at each supply group, route USB or clock nets with intact returns, and avoid trapping power vias behind signal escapes.

• Route away from the lead toe, preserve visible solder fillets, and keep the pin-one cue unambiguous on copper, silkscreen, and the assembly drawing.

Hand assembly is rated hard. Stencil reflow; drag soldering under magnification for rework. Watch for 0.5 mm bridges, bent leads, and missing power-pin decouplers.

• Confirm mask-web capability at 0.5 mm pitch and protect the easily bent leads through receiving, programming, and rework handling.
• Use symmetric paste apertures and a real component courtyard so placement does not rotate or crowd neighboring parts.
• Do not lengthen every pad for hand soldering on the production footprint; excessive toe extension consumes routing and can increase solder movement.

Inspection focus:

• Inspect lead coplanarity and all four rows at magnification; programming success alone does not prove every analog, debug, or peripheral lead is soldered.
• All lead toes should be optically accessible. Inspect alignment, heel/toe wetting, bridges, lifted leads, and orientation before functional test.

Common mistakes:

• Choosing a 7 × 7 mm body from a footprint name while overlooking a 9 × 9 mm lead span mismatch moves every lead toe off center.
• Never infer functional pin numbering from another IC in the same mechanical family; verify symbol, footprint, and datasheet together.

1. Before approving LQFP-48 7×7 mm, compare the exact orderable-device drawing with the library item: body range (7.0 × 7.0 mm nominal), terminal or lead span (About 9.0 mm including leads), pitch (0.5 mm), pin count (48; 12 per side), height (Typically 1.4–1.6 mm), and exposed-pad definition (None on standard LQFP). Record the source drawing revision and every intentional courtyard, toe, heel, side, mask, or paste adjustment.
2. Treat the hard hand-solder rating as a prototype-planning input, not proof of production yield. Review 0.5 mm bridges, bent leads, and missing power-pin decouplers with the assembler, confirm that stencil reflow; drag soldering under magnification for rework is compatible with the build, and require the S1 connectivity gate plus relevant S2 geometry checks to pass against the released footprint and selected fabrication profile.

Manufacturing gate checks:

1. S1Pad count, numbering, and schematic parity. Forty-eight-pad parity, all power pins, pin-one orientation, mask slivers, and exact body/lead span are mandatory checks.
2. S2Lead-to-pad alignment and solder-mask web. Pitch, toe extension, and mask slivers must fit the selected assembly capability without hiding a lead.
3. S2Courtyard and body clearance. The body, leads, placement tolerance, rework access, and nearby height limits all belong in the manufacturing review.