Straight, Right-Angle and SMT Pin Headers: PCB Design Notes

Mounting style is a mechanical decision

Schematics often say only “1×10P 2.54mm header”. Layout then discovers a height limit, a side-exit cable, or a factory that no longer runs wave solder. Choose the mounting style with the enclosure, not as a last-minute footprint swap.

When to use each style

• Straight THT (180°): best mechanical strength for repeated mating, DIN-rail modules and heavy cables. Pin length must cover board thickness plus 1–2mm for the solder fillet.
• Right-angle (90°): board-edge exit for rear I/O and stacked boards. Check 3D keep-outs for walls, heat sinks and cable bend radius.
• SMT: for full reflow and density. Insulator must survive reflow (PA6T / LCP). Add locating pegs or auxiliary THT posts on high pin-count parts because peel strength is lower than through-hole.

Layout checklist

• Finished hole = pin diameter + 0.10–0.20mm; confirm PTH compatibility with your solder process.
• Keep a hand/tool zone in front of right-angle headers.
• SMT pads must cover the lead; locating pegs need matching non-plated holes.
• For long SMT strips, consider adhesive or end support to reduce tombstoning and lifted pins after reflow.

Junjia PAS / PAR / PAM series map to straight, right-angle and SMT. Share board thickness, height limit and cable direction for a pin-length recommendation before tooling changes.