EVX10AS008BGL ETC-unknow, EVX10AS008BGL Datasheet - Page 25

• Manufacturer Part Number: EVX10AS008BGL
• Description: Adc Single 2.2gsps 10-bit Lvds 152-pin Cbga
• Manufacturer: ETC-unknow

5.2
5.3
e2v semiconductors SAS 2008
Thermal Dissipation by Conduction Only (CBGA 152)
Dissipation by Conduction and Convection (CI-CGA 152)
Cooling system efficiency can be monitored using the temperature sensing diodes, integrated in the
device.
When external heatsink cannot be used the relevant thermal resistance is thermal resistance from junc-
tion to bottom of balls:
RTH
package, and balls (Sn63Pb37). Finite Element Method (FEM) with thermal simulator lead to RTH
of balls
case, no radiation and no convection applied). With such assumption the RTH
pendent. To complete thermal analysis, user must add the thermal resistance from top of board (on
which is soldered the device) to ambient, which value is user dependent (type of board, thermal via, area
covered by copper in each layer of the board, thickness, airflow or cold plate are parameters to
consider).
The thermal resistance from junction to ambient RTH
is mandatory to use an external heat sink to improve dissipation by convection and conduction. The heat
sink should be fixed in contact with the top side of the package (AI203 isolation over CuW heat
spreader).
The heat sink does not need to be electrically isolated, because the top of the package is already electri-
cally isolated thanks to a 0.30 mm AI203 layer.
Example:
Assuming:
Note:
The thermal resistance from case to ambient RTH
with the heat sink depicted in
(respectively L x l x H).
The global junction to ambient thermal resistance RTH
4.8°C/W RTH
10.8°C/W total (RTH
A typical thermal resistance from the junction to the top of the case RTH
method thermal simulation results): this value does not include the thermal contact resistance
between the package and the external heat sink (glue, paste, or thermal foil interface, for example).
As an example, use a 2.0°C/W value for a 50 µm thickness of thermal grease.
J-Bottom-of-balls
= 12.3°C/Watt. This value assume pure conduction from junction to bottom of balls.(that is worst
Example of the calculation of the ambient temperature T
assuming RTH
4.0) = 66.8°C. T
. Thermal path, in this case, is junction, then silicon, glue, CuW heatspreader, Al2O3 of
JC
+ 2.0°C/W thermal grease resistance + 4.0°C/W RTH
JA
A
= 10.8°C/W and power dissipation = 4.0W, T
JA
max can be increased by lowering RTH
).
Figure 5-2 on page
JA
CA
is around 30°C/W. Therefore, to lower RTH
26, of dimensions 50 mm x 50 mm x 28 mm
is typically 4.0°C/W (0 m/s air flow or still air)
JA
A
JA
max to ensure T
is:
with an adequate air flow (2 m/s, for example).
A
max = T
J
- (RTH
JC
J
max = 110°C:
of 4.35°C/W (finite element
J- Bottom-of-balls
CA
JA
EV10AS008B
0811A–BDC–12/08
x 4.0W) = 110 - (10.8 x
(case to ambient) =
is user inde-
J-bottom
JA
, it
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