BERGSTIK II: Amphenol 2.54mm Through-Hole Pin Header System

The BERGSTIK II family is Amphenol's workhorse 2.54 mm (0.100") pitch pin header line — the rectangular connector backbone you reach for when you need reliable board-to-board, wire-to-board, or mezzanine stacking in through-hole form. Every variant in this 391-part series shares the same 0.64 mm square post geometry, so mating with standard dual-leaf receptacle contacts from the BERGSTIK / Minitek / Dubox ecosystem is mechanically guaranteed. If you have ever laid out a prototype on 0.1" perfboard or dropped a Raspberry Pi HAT onto a baseboard, you have already used something that intermates with the BERGSTIK II interface standard.

Physically, these are unshrouded headers — no polarizing walls, no latching — which means you trade mating guidance for maximum placement flexibility and the lowest installed cost per position in the category. The insulator is glass-filled thermoplastic rated for reflow and wave soldering, and the pin plating spans from selective gold (30 microinches over nickel) down to pure tin for cost-sensitive builds where you do not need the durability of a gold wipe.

Where You Will Find BERGSTIK II Headers

The 2.54 mm grid is still the dominant interconnect pitch in industrial and instrumentation equipment, even as consumer portables shift to sub-millimeter pitches. Specific places these headers land:

• PLC and I/O modules — unshrouded vertical headers mate with ribbon-cable IDC sockets to bring field-wiring terminal blocks onto a controller board. The absence of a shroud lets you stack a taller connector alongside without mechanical interference.
• Sensor breakout boards — a dual-row right-angle header turns a MEMS or gas-sensor daughtercard into a pluggable module that mates perpendicular to a backplane, keeping the sensor aperture facing outward.
• Programming / debug headers — the classic 2x5 10-position footprint (Cortex Debug, AVR ISP, PIC ICSP) is almost universally implemented with BERGSTIK II or a pin-compatible clone. Gold plating is worth the premium here because debug headers see hundreds of insertion cycles over the life of a development board.
• Backplane risers and mezzanine cards — long-tail variants (up to 15 mm tail length on the solder side) let you pass signals through a 3.2 mm thick backplane and still have enough post height on the component side to mate a daughtercard.
• Power distribution — the square-post cross-section carries 3 A per contact (single contact in free air, 25°C rise), so a 4-position single-row header handles a 12 A rail with margin on a 2-oz copper plane.

Key Specifications

How to Pick the Right Variant

With 391 SKUs, the decision tree is mechanical, not electrical — the electrical interface is identical across the series. Work through these questions in order:

1. Single row, dual row, or triple row? Your PCB real estate usually answers this. Dual row packs more positions per linear millimeter but forces a wider board cutout; single row is easier to hand-solder and inspect.
2. Straight or right-angle? Straight (vertical) works when the daughterboard sits parallel to the motherboard. Right-angle points the mating face parallel to the board plane — ideal when you are sliding a card into a card cage or mounting a display module flush against a chassis wall.
3. Tail length — measure your board thickness and add 0.5 mm for solder fillet on the far side. If you are press-fitting into a plated-through hole on a 1.6 mm board, the standard 2.4–3.0 mm tail is enough. For a 3.2 mm backplane, grab the 4.5 mm tail.
4. Gold vs. tin — gold if mates exceed ~25 field cycles or if the board sits in a condensing-humidity environment (tin whiskers are real). Tin is fine for one-time assembly, especially with a wiped-contact receptacle that breaks the oxide layer on first insertion.
5. Breakaway vs. fixed-length — many BERGSTIK II parts ship as breakaway strips (e.g., a 36-position single-row strip you snap to your desired count with pliers). This reduces your BOM line items if you use the same header family at multiple pin counts across one design.

Comparison: BERGSTIK II vs. Minitek Pwr 3.0

If you are tempted to bump to a larger pitch for higher current, compare carefully: Minitek Pwr 3.0 gives you 5 A per contact at 3.0 mm pitch, but it breaks the 0.1" grid ecosystem — your prototyping tools, IDC ribbon cables, and standard perfboard layouts no longer align. BERGSTIK II at 2.54 mm carries enough current for logic, sensor, and low-side drive signals while keeping the entire BOM on one grid. Only move to a larger pitch when you genuinely need the ampacity or when vibration demands a latched shroud that is unavailable in the BERGSTIK II unshrouded form factor.

Availability and Sourcing

Amphenol ICC manufactures BERGSTIK II across multiple fabs, and the 2.54 mm pin header category is one of the deepest in interconnect distribution. Most positions and plating combinations show lead times under six weeks from authorized distribution (Digi-Key, Mouser, Farnell). The breakaway strip variants are typically stocked in depth because a single SKU serves dozens of pin counts. If a specific part number runs long, a substitute with the same pitch / row count / plating but a different tail length is usually pin-compatible as long as you revalidate the solder-side protrusion on your board stack-up. Gold-plated dual-row parts in mid-range position counts (10–30) are the highest-velocity items; odd-position-count single-row parts sometimes show spot shortages during Q3 back-to-school build cycles.