The rack, cabinet, or drawer environment for the drive must provide heat removal from the electronics and head and disc assembly (HDA). You should confirm that adequate heat removal is provided using the temperature measurement guidelines described in the Temperature Limits section below.
Forced air flow may be required to keep temperatures at or below the specified case temperatures of Table 1, in which case the drive should be oriented, or air flow directed, so that the least amount of air flow resistance is created while providing air flow to the electronics and HDA. Also, the shortest possible path between the air inlet and exit should be chosen to minimize the travel length of air heated by the drive and other heat sources within the rack, cabinet, or drawer environment.
If forced air is determined to be necessary, possible air-flow patterns are shown in Figure 1. The air-flow patterns are created by one or more fans, either forcing or drawing air as shown in the illustrations. Conduction, convection, or other forced air-flow patterns are acceptable as long as the temperature measurement guidelines in the Temperature Limits section below are met.
Figure 1. Air Flow
Temperature Limits
Operating
With cooling designed to maintain the case temperatures of Table 1, the drive meets all specifications over a 41°F to 131°F (5°C to 55°C) drive ambient temperature range with a maximum temperature gradient of 36°F (20°C) per hour. The enclosure for the drive should be designed such that the temperatures at the locations specified in Table 1 are not exceeded. Air flow may be needed to achieve these temperature values (see Providing Air Flow above). Operation at case temperatures above these values may adversely affect the drive's ability to meet specifications.
The MTBF specification for the drive is based on operating in an environment that ensures that the case temperatures specified in Table 1 are not exceeded. Occasional excursions to drive ambient temperatures of 131°F (55°C) or 41°F (5°C) may occur without impact to specified MTBF. Air flow may be needed to achieve these temperatures (see Providing Air Flow above). Continual or sustained operation at case temperatures above these values may degrade MTBF.
To confirm that the required cooling for the electronics and HDA is provided, place the drive in its final mechanical configuration, perform random write/read operations. After the temperatures stabilize, measure the case temperature of the components listed in Table 1 (see note [2]).
The maximum allowable HDA case temperature is 65°C. Operation of the drive at the maximum case temperature is intended for short time periods only. Continuous operation at the elevated temperatures will reduce product reliability.
Table 1. PCBA and HDA Temperatures
Items in
Figure 2
Maximum allowable
case temperature (°C) operating
Maximum allowable
case [3] temperatures (°C) to meet MTBF spec.
HDA [2]
65
50
1 (Processor)
74
54
2 (A/D Demod)
88
68
3 (FC Interface)
93
73
4 (Motor Driver)
78
58
NOTES:
[1] The section above (Providing Air Flow) describes the air-flow patterns used when generating the 1,200,000 hours MTBF guidelines in column 2. Air flow was opposite that shown in Figure 1 above. Local air velocity was 0.92 m/sec (180 lfpm). Inlet air temperature to the drive was 77°F (25°C), plus 9°F (5°C) temperature rise in the test enclosure (86°F/30°C ambient local to the drive).
[2] Measure HDA temp at point labeled "HDA" on Figure 2 below.
[3] PCB mounted integrated circuit case.
Non-operating
–40° to 158°F (–40° to 70°C) package ambient with a maximum gradient of 36°F (20°C) per hour. This specification assumes that the drive is packaged in the shipping container designed by Seagate for use with drive.
Figure 2. Locations of PCBA Components Listed in Table 1
