Omnigrid

The trend to standardize packaging systems for electronics into true metric was caused by the disruption of the existing systems, where metric PCB's (160 mm by 100 mm) were packed into 19 inch racks and composed of connectors spaced 1/10 of an inch from each other.

In order to find a true metric system, an IEC (IEC Publ. 102-4-100) standard for packaging was proposed, which is based on the existing DIN 43356 "metric design standard multi module 2.5 mm". This metric design standard defines a sub-unit (SU) of 25 mm (.98425 inch) which is described in all three dimen-sions "omnidirectional" like a cube with 25 mm width. The sub-unit can be divided into 10 increments of 2.5 mm. A multiple of these increments constitutes the board spacing with a minimum spacing of 15 mm.

The 3D grid is conceived so that it is possible to have a pin every 2.5 mm in X and Y direction on the back-plane. Connectors can therefore mate in the X direction or in the Y direction on the same backplane. This allows for maximum utilization of system volume and for very high pin count between the module and backplane.

One of the first connectors designed for this metric packaging standard is the Omnigrid 2.5 connector system. This standard was developed in 1986 according to the DIN 41642 standard in Germany and has now become the IEC 1076-4-100 specification titled - Detail specification for modular two-part connectors for printed boards and backplanes, grid of 2.5 mm (0.098 in) according to IEC 917". This specification highlights the wide acceptance of this connector as an industry standard.

The IEC 1076-4-100 has been accepted as the COMBUS standard by a majority of the leading Telecom manufacturers, worldwide. Omnigrid 2.5 - featured in this catalog - is a true metric connector system and uses the minimum PCB spacing of 15 mm for a rugged and reliable Female-to-PCB and Male-to-Backplane inverted interconnection system.

Molex's Omnigrid 2.5 mm connector family is a 5 row backplane connector system with female contacts on the module and pins on the backplane. Both the female and backplane pins are press-fitted into the board, not requiring solder. It is important to note that high pin counts are achieved without any compromises in technology.

The backplane is fitted with 0.6 mm square C-pins utilizing the compliant press fit technology proven in billions of pins used in previous generation DIN 41612 connectors.

The female contact is a dual beam, low insertion force contact with versions available to meet the Bellcore requirement for 100 grams minimum normal force after life. This capability provides the high reliability needed to achieve system level Mean Time Between Failure (MTBF) requirements.

The female contact uses a V-press fit technology so that this connector can also be applied without soldering, making the Omnigrid 2.5 mm connector the perfect high pin count connector for surface mount boards. It also shortens electrical length and enables board to board spacing as low as 15 mm. A 10 SU long connector, it offers 475 circuits on a 265 mm high PCB edge.

The rear I/O behind backplane plugging system enables 1, 2, and 4 SU cable plugs with up to 164 signal paths and can be plugged omnidirectionally (vertically or horizontally) in order to connect one peripheral cable onto up to eight PCB+s. First-Make-Last-Break (two levels) and Last-Make-First-Break male contacts are available as well as four different rear tail length for press fit only, rear I/O only, or wire wrap and rear I/O wiring applications.

Last, but not least Molex's highly automated production equipment enables the customer to tailor his product to the actual needs as pseudo-coax arrangements or selectively loaded connectors depending on his application.