Mounting the Printed Circuit Board

The OEM7 family receiver cards are OEM products and the printed circuit board is provided without a housing structure. This allows flexibility in creating a mounting environment to suit particular product and market requirements.

The mounting and enclosure should provide for the following:

  • Mounting of external connectors

  • Protection from hostile physical environments (rain, snow, sand, salt, water, extreme temperatures, etc)

    The OEM Integrator is responsible for ensuring compliance of the final product with the regulatory bodies for those intended markets.

  • Protection from ESD (see Electrostatic Discharge (ESD) Practices)

  • Location to securely mount the receiver using screws

Planning the Mount Location

When planning the mount location for the OEM7 receiver, ensure there is enough room for the card. There is an area around the card, called a keep-out zone, where other components in the enclosure can not intrude. This keep-out zone is intended to prevent other components in the enclosure from interfering with, or damaging, the OEM7 receiver. For diagrams of the exact dimensions and keep-out zones for each OEM7 receiver card, see:

OEM7 receivers are not directional in nature and can be mounted in any orientation.

Board to Board Spacing

A minimum amount of space is required between the OEM7 receiver and the interface or system board the receiver connects to. Refer to the following table for the minimum and suggested spacing.

OEM7 Receiver

Antenna Connector Type

Minimum Spacing

Suggested Spacing

Notes

OEM719

MCX straight

11.00 mm

12.00 mm

Mounting rails are available from NovAtel.

See Table: NovAtel Mounting Rails for the rails available.

OEM719A

MCX right angle

7.00 mm

7.00 mm
10.00 mm
12.00 mm

OEM719B

MMBX straight

7.00 mm

7.00 mm
10.00 mm
12.00 mm

OEM7600

MMCX right angle

7.00 mm

7.00 mm

OEM7700

MMBX straight

7.00 mm

7.00 mm
10.00 mm

OEM7720

MMBX straight

7.00 mm

7.00 mm
10.00 mm

The recommended minimum values in the previous table assumes no recesses or cut-outs in the interface or system board for antenna connection.

A component keep-out area may be needed below the antenna connector on the mating interface or system board to facilitate minimum or suggested spacing.

Board to board spacing less than the minimum spacing suggested in the table may be achieved by incorporating recesses or cut-outs in mating interface or system board.

Mounting Options

OEM7 receivers can be mounted using standoffs, rails or rails and clamping bars.

The OEM7600 has integrated mounting rails and does not required additional standoffs, rails or clamping bars. See Mounting the OEM7600 for mounting details.

Mounting with Standoffs

Mounting with Rails

Mounting with Rails and Clamping Bars

The mounting holes in the OEM7 receiver cards accept M3 fasteners with a maximum projected head diameter of 7.5 mm (0.295"). For the exact spacing of the mounting holes, see Figure: OEM719 Dimensions, Figure: OEM729 Dimensions, Figure: OEM7700 Dimensions and Figure: OEM7720 Dimensions.

For proper grounding and mechanical integrity, mount the OEM719, OEM7700 and OEM7720 with four screws.

For proper grounding and mechanical integrity, mount the OEM729 with six screws.

When installing cards, ensure all standoffs are properly installed.

Also ensure that the mounting location (whether using standoffs, bosses or rails) is level.

The amount of board deflection (bow and twist) must not exceed 0.75% of the receiver card's characteristic dimension. For example, on the OEM7700, which is 71 mm long and 46 mm wide, the deflection along the length must not exceed 0.53 mm and the deflection along the width must not exceed 0.34 mm.

Care needs to be taken when mating the OEM7700 or OEM7720 receiver to an interface card or system board. The high-density, 60 position connectors on both cards need to be properly aligned before mating to prevent damage to the connectors. See Figure: Mounting the High-Density, 60 Pin Connector.

A method to ensure proper alignment of the connectors is to slowly bring the mating faces together and let the connectors find their centers as the mating faces come to rest against each other. At this stage, visually check that the connectors are aligned. If the connectors are aligned, gently push the connectors together to mate them.

A fixture or jig will also be of help in ensuring proper alignment between the two connectors.

Mounting the High-Density, 60 Pin Connector

OEM7 receivers have an area on the edge of the cards to allow the use of mounting rails. This is the area of bare copper outside of the keep-out zone. On the OEM719, OEM7700 and OEM7720, this area is 1.75 mm wide. On the OEM729, this area is 2.5 mm wide. See Figure: OEM719 Mounting Surface, Figure: OEM729 Mounting Surfaces, Figure: OEM7700 Mounting Surfaces and Figure: OEM7720 Mounting Surfaces for the dimensions of this area.

For most non-demanding applications (e.g. base stations, remote sensing, desktop units and IT infrastructure), standoffs or bosses are sufficient to provide a secure mounting location.

Using rails to mount the OEM7 receiver improves the thermal and vibration performance of the receiver. Securing the OEM7 receiver to mounting rails using additional rails as clamping bars provides the most secure configuration for aggressive thermal and vibration applications. See Table: NovAtel Mounting Rails for information about the OEM7 mounting rails available from NovAtel.

NovAtel Mounting Rails

Rail Part Number

Rail Height

Use as Mounting Rail for

Use as Clamping Bar on

01019750

7 mm

OEM719
OEM7700
OEM7720

OEM719
OEM7700
OEM7720

01019751

10 mm

OEM719
OEM7700
OEM7720

OEM719
OEM7700
OEM7720

01019752

12 mm

OEM719

OEM719
OEM7700
OEM7720

Ensure the IO connector height and antenna cable/connector height facilitate the desired board to board spacing and do not violate OEM7 receiver card height keep-out zones.

For more details about mounting OEM7 receiver cards, contact Customer Support to obtain to the OEM7 Receiver Card Mechanical Integration Application Note (D19021) or OEM7600 Mechanical Application Note (D21177).

Mounting the OEM7600

The OEM7600 mounts to the interface or system board using four screws that pass through the interface board and into the mounting holes on the OEM7600 RF shield. For the exact spacing of the mounting holes, see Figure: OEM7600 Dimensions.

Mounting the OEM7600

The mounting holes in the OEM7600 accept M3 fasteners. For proper grounding and mechanical integrity, mount the OEM7600 with four screws. The recommended torque rate for the mounting screws is 8 in-lbs.

The optimal screw penetration into the OEM7600 is 4.0 mm deep. When selecting screws for mounting the OEM7600, ensure the maximum screw penetration does not exceed 5 mm.

Care needs to be taken when mating the OEM7600 receiver to an interface card or system board. The high-density, 60 position connectors on both cards need to be properly aligned before mating to prevent damage to the connectors. See Figure: Mounting the High-Density, 60 Pin Connector.

A method to ensure proper alignment of the connectors is to slowly bring the mating faces together and let the connectors find their centers as the mating faces come to rest against each other. At this stage, visually check that the connectors are aligned. If the connectors are aligned, gently push the connectors together to mate them.

A fixture or jig will also be of help in ensuring proper alignment between the two connectors.

Thermal Dissipation

To ensure functionality and reliability, the OEM7 receiver cards must operate within the specified ambient air temperature limits (-40°C to +85°C).

The OEM7 receivers have been designed to efficiently transfer heat from the receiver components into the printed circuit board. Mounting the OEM7 receiver on rails, or attaching heat sinks to the mounting areas, will transfer the heat from the receiver card to adjacent circuit boards, the enclosure or the air.

The mounting area is the area of bare copper on the sides of the receiver that are outside of the keep-out zone. See Figure: OEM719 Mounting Surface, Figure: OEM729 Mounting Surfaces, Figure: OEM7700 Mounting Surfaces and Figure: OEM7720 Mounting Surfaces .

The OEM7600 receiver RF shield has integrated mounting rails.

For more information about thermal dissipation, contact Customer Support to obtain to the OEM7 Receiver Card Mechanical Integration Application Note (D19021) or OEM7600 Mechanical Application Note (D21177).

OEM7720 Accessory Heat Spreader

The NovAtel Heat Spreader accessory (01020014) dissipates heat quickly to reduce component temperatures. Four M3 flat head screws are required to attach the Heat Spreader to the OEM7720 card (on the non-connector side) and two thermal interface pads need to be added. If necessary, mounting rails can also be used on the connector side of the OEM7720 card. Refer to Figure: Mounting with Rails and Table: NovAtel Mounting Rails for mounting rail details.

OEM7720 Heat Spreader Mounting Geometry

Vibration

OEM7 receivers are rated to 20 g RMS (MIL-STD_810G Method 514.6E-1, Category 24). However, for high vibration installations, special considerations are required.

For OEM719, OEM7700 and OEM7720 receiver cards to meet the 20 g vibration rating, the receiver card must be mounted using rails. OEM729 receivers meet the 20 g vibration rating using standoffs, bosses or rails. The OEM7600 receiver RF shield has integrated mounting rails and meets the 20 g vibration rating.

For more information about vibration considerations, contact Customer Support to obtain to the OEM7 Receiver Card Mechanical Integration Application Note (D19021) or OEM7600 Mechanical Application Note (D21177)

 

OM-20000167 v12

July 2019

Email comments to NovAtel_TPUBS@NovAtel.com

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