D2PAK TO-263 Footprint: Thermal Layout, DFM, Assembly Guide

D2PAK / TO-263 is a power package package used for surface mount assembly, also seen labeled TO-263, D2PAK, DDPAK. A dependable footprint follows the exact orderable-device drawing rather than the family name: nominal body About 10 × 9 mm excluding leads, overall span Often 15–16 mm including leads, seated height Typically 4.3–4.8 mm, pitch About 2.54 mm between lead positions, pin count 2–7 lead options plus a large tab, and exposed pad Large electrically active rear tab.

Use the exact TO-263 lead count, tab, body, and thermal recommendation; multiple lead options share the family name.

Typical uses include high-current MOSFETs, power regulators, rectifiers. TO-263/D2PAK includes several lead counts and outlines; use the full package suffix and exact MPN drawing.

• D2PAK is materially larger and heavier than DPAK. Its tab can dissipate useful power only when the PCB copper and assembly joint are designed as part of the heatsink.
• The large tab or thermal pad is commonly an electrical terminal as well as the main heat path; its net and land geometry come from the exact device drawing.

Provide broad force-current paths, a low-inductance gate or feedback loop, a reviewed thermal-via field, and adequate clearance around the live tab net.

• Size copper and thermal vias from loss and temperature-rise calculations, keep current paths broad, and isolate heat-sensitive feedback or timing parts from the hot region.

Hand assembly is rated expert-only. High-thermal-capacity profiled reflow; strong preheat for rework. Watch for package float, center voiding, secondary-side drop, and unsafe thermal claims.

• Window the large paste area, agree void limits and via fill, check second-side mass, and use a reflow profile that heats the entire copper region evenly.
• Large thermal lands often need segmented paste and a controlled via-fill strategy to avoid solder loss, floating, or excessive voiding.
• Verify copper weight, thermal relief policy, stencil thickness, and secondary-side mass limits with the chosen assembly process.

Inspection focus:

• X-ray the tab, inspect all accessible leads, and load-test voltage drop, switching behavior, and temperature rise in the intended airflow.
• Inspect accessible leads, then use X-ray, electrical loading, and temperature measurements as appropriate because the most important thermal joint may be hidden.

Common mistakes:

• Quoting the semiconductor's current rating without checking lead, copper, connector, thermal, and safe-operating-area limits creates a dangerous board claim.
• Do not connect the tab by package habit; regulator outputs, transistor drains, and grounds can all occupy the large terminal in related outlines.

1. Before approving D2PAK / TO-263, compare the exact orderable-device drawing with the library item: body range (About 10 × 9 mm excluding leads), terminal or lead span (Often 15–16 mm including leads), pitch (About 2.54 mm between lead positions), pin count (2–7 lead options plus a large tab), height (Typically 4.3–4.8 mm), and exposed-pad definition (Large electrically active rear tab). 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 package float, center voiding, secondary-side drop, and unsafe thermal claims with the assembler, confirm that high-thermal-capacity profiled reflow; strong preheat 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. Exact lead option, live tab net, current widths, thermal vias, clearance, paste process, and temperature assumptions need evidence.
2. S1Thermal-pad net, vias, and copper necks. A wrong tab net is a short; an inadequate or paste-draining thermal land can also invalidate the device's power rating.
3. S2Courtyard and body clearance. The body, leads, placement tolerance, rework access, and nearby height limits all belong in the manufacturing review.