TSSOP-8 PCB Footprint: Dimensions, DFM, and Assembly Guide

TSSOP-8 is a gull wing package used for surface mount assembly, also seen labeled thin shrink small outline 8, MO-153 variants. A dependable footprint follows the exact orderable-device drawing rather than the family name: nominal body About 3.0 × 3.0 mm, overall span About 4.9 mm lead span, seated height Typically 1.0–1.2 mm, pitch 0.65 mm, pin count 8, and exposed pad Normally none; PowerPAD variants differ.

Use the exact manufacturer drawing; TSSOP, MSOP, VSSOP, and exposed-pad variants can share pin count but not geometry.

Typical uses include precision amplifiers, small converters, interface ICs. TSSOP-8 drawings vary in body length and lead span; MO-153 family references do not replace the MPN package page.

• The 0.65 mm pitch halves SOIC's lead spacing while the thin body lowers height, making pad-width and mask-registration choices more process-sensitive.
• Gull-wing package names cover families of drawings; body width, lead span, lead length, and seated height must all match the orderable part.

Escape traces from the pad ends with consistent neck widths and keep nearby vias out of the solder fillet and rework path.

• 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 moderate. Stencil reflow or flux-rich drag soldering under magnification. Watch for solder bridges and confusing tssop with msop or vssop.

• Confirm whether the fab can maintain mask slivers between the 0.65 mm-pitch pads; gang mask openings change solder control and must be intentional.
• 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 for fine bridges at both heel and toe, lifted corner leads, and package skew; a continuity test should follow visual review.
• All lead toes should be optically accessible. Inspect alignment, heel/toe wetting, bridges, lifted leads, and orientation before functional test.

Common mistakes:

• A generic eight-pin small-outline footprint can be dimensionally plausible while placing every lead partly off pad.
• Never infer functional pin numbering from another IC in the same mechanical family; verify symbol, footprint, and datasheet together.

1. Before approving TSSOP-8, compare the exact orderable-device drawing with the library item: body range (About 3.0 × 3.0 mm), terminal or lead span (About 4.9 mm lead span), pitch (0.65 mm), pin count (8), height (Typically 1.0–1.2 mm), and exposed-pad definition (Normally none; PowerPAD variants differ). Record the source drawing revision and every intentional courtyard, toe, heel, side, mask, or paste adjustment.
2. Treat the moderate hand-solder rating as a prototype-planning input, not proof of production yield. Review solder bridges and confusing tssop with msop or vssop with the assembler, confirm that stencil reflow or flux-rich drag soldering under magnification 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. Package family, 0.65 mm pitch, pad width, and any exposed-pad requirement must be checked together rather than inferred from pin count.
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.