SON-6 2×2 mm Footprint: DFM, Layout, and Assembly Guide

SON-6 2×2 mm is a no lead package used for surface mount assembly, also seen labeled 6-SON, WSON-6, 0.65 mm-pitch SON. A dependable footprint follows the exact orderable-device drawing rather than the family name: nominal body 2.0 × 2.0 mm nominal, overall span 2.0 × 2.0 mm body, seated height Often 0.7–0.8 mm, pitch 0.65 mm, pin count 6 perimeter terminals plus optional thermal pad, and exposed pad Common on WSON variants.

Use the selected package's terminal length, side metallization, and center-pad drawing; SON naming is not uniform.

Typical uses include logic gates, small regulators, protection devices. SON and WSON labels cover multiple terminal and pad styles; exact manufacturer geometry is mandatory.

• Three terminals per side fit a compact square body, while a WSON exposed pad may take most of the center underside.
• A no-lead package is defined by its complete manufacturer drawing: nominal body and pitch do not fix terminal length, pullback, exposed-pad size, or corner geometry.

Keep the signal escape direct and bypassing adjacent, and never route unrelated copper under the package where mask registration is tight.

• Escape outer terminals without narrowing below the fab profile, keep copper out from under the package unless intended, and connect any exposed pad to its documented net.

Hand assembly is rated expert-only. Fine stencil and reflow. Watch for vendor-specific son/wson naming and invisible opens.

• Confirm whether the terminal flank is wettable and how the assembler will inspect a joint with little or no visible side fillet.
• Use a windowed or otherwise reduced paste pattern on a large exposed pad so the body is not floated above its perimeter joints.
• Agree mask-defined versus non-mask-defined geometry, via fill, and inspection method with the assembler before release.

Inspection focus:

• Use X-ray or proven process controls for hidden joints and verify the device at voltage, load, or edge rate representative of use.
• Perimeter wetting may be only partly visible and the center pad is hidden. Use X-ray or validated process evidence when voiding and opens matter.

Common mistakes:

• Substituting a nominal SON-6 alternate without comparing the exposed pad can create a copper short beneath an otherwise aligned body.
• Do not copy a generic QFN, DFN, or SON footprint with the right pin count but a different exposed pad or terminal pullback.

1. Before approving SON-6 2×2 mm, compare the exact orderable-device drawing with the library item: body range (2.0 × 2.0 mm nominal), terminal or lead span (2.0 × 2.0 mm body), pitch (0.65 mm), pin count (6 perimeter terminals plus optional thermal pad), height (Often 0.7–0.8 mm), and exposed-pad definition (Common on WSON variants). Record the source drawing revision and every intentional courtyard, toe, heel, side, mask, or paste adjustment.
2. Treat the expert-only hand-solder rating as a prototype-planning input, not proof of production yield. Review vendor-specific son/wson naming and invisible opens with the assembler, confirm that fine stencil and reflow 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 code, six terminals, center pad, pin-one mark, and mask clearance must agree across the full release package.
2. S1Exposed-pad connectivity and paste segmentation. A missing or wrongly netted center pad can break electrical, thermal, and mechanical performance while remaining visually hidden.
3. S2Courtyard and body clearance. The body, leads, placement tolerance, rework access, and nearby height limits all belong in the manufacturing review.