Multi-pin board-to-board connectors float 0.5mm for better alignment

Harwin has launched a range of multi-GHz multi-pin board-to-board connectors that tolerate slight misalignment, shock and vibration.

Branded Flecto, they are double-row, with up to 160 contacts, and come in three pitches: 0.5, 0.635 (.025in) or 0.8mm, for mated board-to-board spacings between 7.2mm and 29.9mm.

The connectors are two-part – one for each board.

Controlled flexibility comes from making one of those two parts from two separate polymer mouldings, between which flexible springy conductors pass (cross-section diagram left).

The design is such that some displacement and movement in any direction parallel to the boards can be tolerated.

“By accommodating movement of up to ±0.5 mm in both the X and Y axes, Flecto allows for accurate placement of multiple connectors between the same two PCBs where the sum of misalignments might, otherwise, present challenges for high-speed, high-precision mating,” according to the company. This movement can also maintain “connection integrity during shock and vibration, and reduce the possibility of degradation from fretting”.

Vertically, the contacts are long enough that wiping allows ±0.5mm of movement without electrical disconnection, allowing for PCB flex or stand-off tolerance, for example.

A few members of the family are designed to handle ±0.8mm of movement or displacement in all three directions.

Vibration has been tested between 10 and 55Hz with 1.5mm amplitude in three axes for two hours each with no electrical disconnection, Harwin v-p of products Ryan Smart told Electronics Weekly.

Bandwidth is at least 2.5GHz, and up to 12GHz in some 0.635mm pitch models, when adjacent pairs of contacts are used in circuits with 100Ω characteristic impedance.

“Vertical and horizontal female connectors allow boards to be connected in parallel or at right angles to each other, while Flecto signal-only connectors feature either location pegs or posts to eliminate movement during solder reflow,” said Harwin. “On the mixed signal and power connectors, through-board solderable posts are provided for location accuracy and enhanced mechanical strength. A number of the connectors feature shrouded contacts to prevent accidental damage when no mating connector is present, while others offer polarization within the shroud to ensure uni-directional mating.”

Power pins are rated at 3A and are located on the alignment pins (photo right). Signal pins are rated at 500mA (or 400mA in ‘F10’ variants).