Ben Paagman, Senior Project Engineer, FCI Netherlands
Marco Pagnin, FAE, FCI Germany
FCI’s AirMax VSTM connector system is the currently proposed connector system as the backplane interface for Compact PCI Plus (CPlus.0). AirMax VS™ is a shieldless High Speed connector system with pressfit technology.
The IMLAs accumulate the contact columns which are insulated from each other by air gaining the highest speed dielectric. (AirMax).
For CPCI+ a version was chosen with four signal pairs per column. As the amount of pairs gives the height of the connector, this is the ideal configuration to maintain the mechanical compatibility to the IEEE 1101.
Another requirement for this application was to get 184 signal pairs (552 single contacts) into 95mm linear card edge, including coding to prevent plugging CPCI+ cards into common CPCI slots. Also it was decided by the PICMG to mount the receptacle part onto the backplane to prevent terminal stubbing on the backplane when card guiding is not optimal.
The AirMax VSTM connectors consists of single insert moulded leadframe assemblies, called IMLAs, which are mounted at a pitch of 2mm in a plastic front housing and a plastic retainer on the back side.
To protect the terminals of the header, AirMax VSTM is available with different wall configurations. Combining headers with a different wall count and a customized version with three walls, the headers are protected from all sides and to offering coding and guiding. On the outer left side the header with the four walls and six IMLAs is placed ( P1 connector), aside the headers with two walls an eight IMLAs side by side and on the outer right side the header with three walls and eight IMLAs (P6 connector). The related receptacles are mounted onto the backplane.
As CPCI+ should also support next generation bus standards, like SATA3.0, PCIe2.0, USB3.0, etc, the backplane connectors must show excellent high speed performance at 10Gbit/s and more. Insertion Loss is less than 0,6 dB @ 10Gb/s and the worse case Crosstalk is less then 3\% @ 50ps signal rise-time ( 10-90\%)
Also the current carrying capacity is an important issue, as a minimum of 60W rating per card has to be supplied. Airmax VS™ is able to deliver this power with 6 terminals without a temperature rise of more than 30 ºC.
A further requirement was the realisation of mezzanine applications on the plug-in boards. (Ethernet options).
Rear I/O applications, direct into the backplane and midplane are both possible to realize with AirMax VSTM