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Loctite Corporation
1001 Trout Brook Crossing
Rocky Hill, CT 06067
AI Technology (e.g., EG7655)
1425 Lower Ferry Rd
Trent, NJ 08618
The following section provides a heat sink selection example using one of the commercially available heat
sinks.
1.8.6.3 Heat Sink Selection Example
For preliminary heat sink sizing, the die-junction temperature can be expressed as follows:
T
= T
+ T
+ (θ
j
a
r
Where:
T
is the die-junction temperature
j
T
is the inlet cabinet ambient temperature
a
T
is the air temperature rise within the computer cabinet
r
θ
is the die junction-to-case thermal resistance
jc
θ
is the adhesive or interface material thermal resistance
int
θ
is the heat sink base-to-ambient thermal resistance
sa
P
is the power dissipated by the device
d
During operation the die-junction temperatures (T
Table 2. The temperature of the air cooling the component greatly depends upon the ambient inlet air
temperature and the air temperature rise within the electronic cabinet. An electronic cabinet inlet-air
) may range from 30 to 40 °C. The air temperature rise within a cabinet (T
temperature (T
a
range of 5 to 10 °C. The thermal resistance of the thermal interface material (θ
1 °C/W. Assuming a T
a
(P
) of 3.0 W, the following expression for T
d
Die-junction temperature: T
For a Thermalloy heat sink #2328B, the heat sink-to-ambient thermal resistance (R
velocity is shown in Figure 16.
26
+ θ
+ θ
) * P
jc
int
sa
d
of 30 °C, a T
of 5 °C a CQFP package θ
r
is obtained:
j
= 30 °C + 5 °C + (2.2 °C/W + 1.0 °C/W + R
j
860-571-5100
609-882-2332
) should be maintained less than the value specified in
j
= 2.2 °C/W, and a power consumption
jc
) may be in the
r
) is typically about
int
) * 3.0 W
sa
) versus airflow
sa
603 Hardware Specifications
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