Kontron COMe-cXLi2 - Manual (Page 55)

Kontron COMe-cXLi2 User’s Guide
www.kontron.com
49
6 Design Consideration
6.1 Thermal Management
A heat-spreader plate (36006-0000-99-0) assembly is available from Kontron
Embedded Modules for the COMe-cXLi2 COM. The heat-spreader plate on top of
this assembly is NOT a heat sink. It works as a COM Express®-standard thermal
interface to be used with a heat sink or other cooling device.
External cooling must be provided to maintain the heat-spreader plate at
proper operating temperatures. Under worst-case conditions, the cooling
mechanism must maintain an ambient air and heat-spreader plate temperature of
85° C or less.
The aluminum slugs and thermal pads on the underside of the heat-spreader
assembly implement thermal interfaces between the heat-spreader plate and the
major heat-generating components on the COMe-cXLi2. About 80 percent of the
power dissipated within the module is conducted to the heat-spreader plate
and can be removed by the cooling solution.
Kontron also has defined a passive heatsink (36006-0000-99-0C01) that can be
used in place of the heat spreader plate to provide additional cooling. You
can use many thermal-management solutions with the heat-spreader plates,
including active and passive approaches. The optimum cooling solution varies,
depending on the COM Express® application and environmental conditions and
the module is fully functional at the full -40C to +85C temperature even
without the heat spreader plate or the passive heatsink. Drawings for both
the heat spreader plate and the passive heatsink are available on request.
Also, see the PICMG COM Express® Design Guide on the PICMG website for
further information about thermal management.
6.2 Heat-Spreader Dimensions
Documentation for the COMe-cXLi2 COM cooling solutions is provided at
http://emdcustomersection.kontron.com .
6.3 Onboard Fan Connector
This section describes how to connect an optional fan to the connector
located directly on the COMe-cXLi2 COM. With certain BIOS-settings it is
possible to control the fan depending on the active trip point temperature.
The fan switches on/off depending on the adjusted Active Trip Point
temperature. In order for this feature to function properly an ACPI compliant
OS is necessary.