What This Header Is
The Amphenol ICC (FCI) 78511-103HLF is the 3-position member of the BERGSTIK II single-row header series, a board-to-board interconnect with 0.100 inch (2.54 mm) pitch and through-hole soldering termination. Square male pins are gold-plated over phosphor bronze at 30.0 µin (0.76 µm) on the mating face, housed in a black UL94 V-0 rated LCP insulator. The push-pull fastening type relies on pin-socket interference fit rather than a latch or screw, which is typical for this density of board-to-board header in test fixtures and signal-routing mezzanine stacks.
Ratings That Drive the Selection
The 110 V rating sits comfortably below the dielectric withstanding limit for the LCP housing at the stated temperature extremes of -65 °C to 125 °C, so the voltage derating path is wide for a standard industrial board stack. The gold plating grade — 30.0 µin (0.76 µm) on the mating side — is the key differentiator against tin-plated siblings in the same series. That thickness supports repeated mating cycles without the surface degradation tin suffers at high cycle counts; for a header that sees field servicing or probe reconnection, the gold finish extends functional life meaningfully. Mating pin length is 0.318 inch (8.08 mm) with a post extension of 0.120 inch (3.05 mm) and overall contact length of 0.538 inch (13.67 mm). The 0.100 inch (2.54 mm) insulation standoff keeps the header body off the board surface during wash or conformal coat — relevant in board-stack or test-fixture assembly where the header sits proud of the PCB plane.
Where It Goes
Board-to-board signal and low-level power routing at 0.100 inch pitch is the canonical fit for BERGSTIK II. The single-row unshrouded pin field suits backpanel daughtercard connections, test-point arrays, and industrial I/O modules where multiple headers are gang-mounted on a common pitch grid. The -65 to 125 °C operating window covers equipment that sees thermal cycling across the full industrial spectrum.