SMA DO-214AC Footprint: Dimensions, DFM, and Assembly Guide

SMA (DO-214AC) is a chip component package used for surface mount assembly, also seen labeled DO-214AC, SMA diode, SMAJ package. A dependable footprint follows the exact orderable-device drawing rather than the family name: nominal body About 4.5 × 2.7 mm, overall span Terminations included, roughly 4.2–4.8 mm long, seated height Typically 2.0–2.3 mm, pitch Two end terminals; no lead pitch, pin count 2, polarized for ordinary diodes, and exposed pad None.

Use the exact DO-214AC device drawing and manufacturer land recommendation; molded body and terminal tolerances vary.

Typical uses include TVS diodes, rectifiers, reverse-polarity protection. DO-214AC defines the SMA outline family; exact land dimensions and electrical ratings come from the selected diode.

• SMA is the smallest common DO-214 molded power-diode size, but it is substantially taller and more thermally demanding than SOD-123.
• A two-terminal size code describes an envelope, not universal termination length, height, polarity, power, or voltage capability.

For TVS service, place it at the connector with a short, broad discharge path and a direct return that does not route surge current through protected circuitry.

• Keep copper and thermal mass reasonably balanced at both ends, and move vias outside the paste-bearing land unless the assembly process is designed for via-in-pad.

Hand assembly is rated easy. Broad-tip soldering with preheat or normal reflow. Watch for reversed cathode, cold joints on large copper, and undersized surge traces.

• Balance copper and paste on both ends and account for package height beneath shields or low-profile enclosures.
• Select the stencil aperture with the assembler; copper, mask, and paste openings solve different process problems.
• Keep brittle ceramic bodies away from panel break lines, mounting hardware, and enclosure features that bend the finished PCB.

Inspection focus:

• Inspect both broad end fillets and polarity, then surge or clamp-test representative assemblies at safe controlled energy.
• Compare the two visible end fillets for wetting, skew, and solder volume, then use electrical test for failures such as cracked ceramics that AOI cannot see.

Common mistakes:

• A TVS located near the connector visually but connected through long thin traces can clamp too late because of trace inductance.
• Do not substitute a resistor, capacitor, LED, fuse, ferrite, or shunt solely because its nominal body code matches.

1. Before approving SMA (DO-214AC), compare the exact orderable-device drawing with the library item: body range (About 4.5 × 2.7 mm), terminal or lead span (Terminations included, roughly 4.2–4.8 mm long), pitch (Two end terminals; no lead pitch), pin count (2, polarized for ordinary diodes), height (Typically 2.0–2.3 mm), and exposed-pad definition (None). Record the source drawing revision and every intentional courtyard, toe, heel, side, mask, or paste adjustment.
2. Treat the easy hand-solder rating as a prototype-planning input, not proof of production yield. Review reversed cathode, cold joints on large copper, and undersized surge traces with the assembler, confirm that broad-tip soldering with preheat or normal 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. Cathode orientation, two-pad connectivity, copper current path, courtyard height, and mask around the broad terminals require review.
2. S2Solder-mask web and paste geometry. Two close lands still need a process-capable mask dam and a paste plan that will not tombstone the body.
3. S2Courtyard and body clearance. The body, leads, placement tolerance, rework access, and nearby height limits all belong in the manufacturing review.