ERNI has developed a solution to the dilemma posed by high pin-count hard-metric (HM) connectors and the need for precision connector mating combined with sufficient play between subrack guide rails and printed-circuit board (PCB) cards.
The answer is Erni's pre-alignment module.
According to the IEC 61076-4-101 standard, a 2mm HM connector may have hundreds of contacts. At the same time, the plug-in board connectors and backplane connectors must mate precisely in order to avoid damage.
On the other hand, there must be play between the cards and rails to avoid compression stress on the PCB.
Erni's pre-alignment module consists of solid metal guides and new guiding systems that offer several optional functions.
For example, there is a kit available with an integrated socket for HM "coding" keys. Instead of using connector pins for coding, more are now available to carry signals.
In addition, there are flattened pre-alignment pins designed to match their mating connector counterparts. Using an octagonal pattern, it will support eight additional coding options.
What's more, electrical contacts can be tailored using the pre-alignment pins for shielding or high-current handling.
The pre-alignment pin with fastening thread is fastened on the backplane and is available for PCB thicknesses of 2.5 to 6 mm, and 6 to 8 mm. The guide bush is mounted on the daughter card with an M4 or M5 screw. The PCB thickness for the daughter card can be 1.6 to 3.5 mm, or 3.5 to 5.5 mm.