Backplane Design

Elma-Mektron use a range of commercially available backplanes, and for many applications these are entirely suitable. However, there are some designs that require a custom backplane and given that volumes can sometimes be small, commercial backplane suppliers are not able to provide a suitable solution, thus Elma-Mektron has developed many of their own backplane designs.

These designs are customer specific and as such programs for quantities as small as 5 off can be justified compared with using conventional backplanes and adding wire wrap and/or paddle cards for I/O wiring.

For example a 12-slot VME64EXT backplane that incorporated approx 1000 I/O tracks ended up with the final design taking up 18 layers. The tracking included in this design was mainly simple point to point but also included matched impedance LVD tracking. The I/O was simplified using 160-way DIN41612 connectors. Finally the backplane design enabled test cables to be produced that used our CableEye ATE to verify and provide test reports for all the I/O cableforms.

ATR enclosure applications are usually very tight for space and therefore many ATR designs need to optimise the space available. In addition, the popularity in the use of CompactPCI is increasing. To accommodate these two requirements Elma-Mektron has produced a new conduction cooled ATR enclosure that includes a conduction cooled custom CompactPCI 5-slot backplane together with flexi-circuits that incorporate 38999 front panel connectors to 2mm connectors on the backplane. This approach greatly improves production efficiency, provides a more robust solution, saves space and improves reliability.

There is an increasing requirement for high-speed data buses on backplanes and many of the design issues involved in achieving this are covered in an application article entitled ‘Custom High Speed CompactPCI Backplane’ from CompactPCI Systems magazine written by Elma-Mektron which discusses a CompactPCI backplane which has 5 Gigabits/second point-to-point Low Voltage Differential Signaling (LVDS). Another article written by Elma-Mektron from VMEbus Systems magazine entitled ‘Bury Your Termination Issues’ covers utilising embedded resistors in a VME 64EXT board design. Both of these articles are available as reprints and a copy of which may be obtained from our Sales Office. These articles may also be viewed and downloaded from the ‘Technical Articles’ section.

Elma-Mektron has designed and manufactured numerous custom backplane designs that are now deployed in service in many various and varied applications. Customers with an enclosure design that could include a custom backplane but are unsure of the economics of undertaking a custom design should consult Elma-Mektron. We would be very pleased to advise on the design concept and our extensive experience in this field could provide for an innovative and economic solution.