CAS Ltd, recently designed a telecom chassis for telecom
manufacturer, Actelis Networks. Actelis supplies high-quality,
high-bandwidth broadband services over existing copper pairs for
a wide range of businesses, utilities, military installations
and government agencies.
The chassis was a 1U configuration (1.75 inches high) and 9.5
inches wide, dissipating approximately 35 W. The design goals
were to ensure that several temperature sensitive components
were within their manufacturer's limits, while at the same time
optimizing fan type and location, and the number, sizes, and
locations of vents. Standard, commercially available, pin fin
heat sinks were chosen.
To optimize the design they used Coolit's OptimizeIt module.
The initial design had one fan and 4 vents. It had several key
electronic components on both sides of the PCB whose
temperatures were at, or exceeding their manufacturers' limits.
The hottest device, a BGA on the component side of the board,
was 5 deg. C over its 91 deg. C limit.
OptimizeIt automatically set up and ran 73 cases and reported
that the design goals could be accomplished with a single Delta
40mm exhaust fan positioned roughly in the middle of the back
wall. It also resized and repositioned the existing vents, and
added an additional vent to the front panel. In the optimum
design, the BGA temperature dropped from 96 deg. C to 88 deg. C,
while the case temperatures of the circuit side components fell
from 95 deg. C to 89 deg C. Click here for the complete story.