SMC DO-214AB Footprint: Dimensions, DFM, and Assembly Guide

SMC (DO-214AB) is a chip component package used for surface mount assembly, also seen labeled DO-214AB, SMC diode, SMCJ package. A dependable footprint follows the exact orderable-device drawing rather than the family name: nominal body About 7.0 × 5.9 mm, overall span Roughly 6.6–7.5 mm long, seated height Typically 2.2–2.7 mm, pitch Two end terminals; no lead pitch, pin count 2, normally polarized, and exposed pad None.

Follow the chosen DO-214AB drawing and surge-device land recommendation; do not enlarge SMB pads by eye.

Typical uses include high-energy TVS, power rectifiers, industrial transient suppression. DO-214AB defines the SMC outline family; land and electrical performance must follow the exact MPN and board conditions.

• SMC is the largest common DO-214 outline and carries significant mass and thermal inertia, affecting placement, reflow, and enclosure clearance.
• A two-terminal size code describes an envelope, not universal termination length, height, polarity, power, or voltage capability.

Use wide copper and a compact surge loop, keeping the protected node downstream and separating high fault current from sensitive ground references.

• 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 moderate. Board preheat and broad-tip soldering or controlled reflow. Watch for cold joints, second-side drop, and narrow copper that defeats the surge rating.

• Check second-side mass limits, thermal balance, stencil volume, panel support, and component height with the assembler.
• 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 the full width of both terminal joints and polarity; validate transient handling and board temperature with controlled test 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:

• Quoting an SMC's headline pulse power while feeding it through thin traces can move the failure into the PCB copper.
• Do not substitute a resistor, capacitor, LED, fuse, ferrite, or shunt solely because its nominal body code matches.

1. Before approving SMC (DO-214AB), compare the exact orderable-device drawing with the library item: body range (About 7.0 × 5.9 mm), terminal or lead span (Roughly 6.6–7.5 mm long), pitch (Two end terminals; no lead pitch), pin count (2, normally polarized), height (Typically 2.2–2.7 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 moderate hand-solder rating as a prototype-planning input, not proof of production yield. Review cold joints, second-side drop, and narrow copper that defeats the surge rating with the assembler, confirm that board preheat and broad-tip soldering or controlled 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. The gate should check polarity, terminal copper necks, courtyard and height, pad geometry, and clearance to neighboring high-energy nets.
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.