STPCI2GDYI STMicroelectronics, STPCI2GDYI Datasheet - Page 101

• Manufacturer Part Number: STPCI2GDYI
• Description: IC SYSTEM-ON-CHIP X86 516-PBGA
• Manufacturer: STMicroelectronics

Specifications of STPCI2GDYI

• Applications: Graphics Controller
• Core Processor: x86
• Controller Series: STPC® Atlas
• Interface: UART
• Number Of I /o: 16
• Voltage - Supply: 2.45 V ~ 2.7 V
• Operating Temperature: -40°C ~ 115°C
• Mounting Type: Surface Mount
• Package / Case: 516-PBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Program Memory Type: -
• Ram Size: -
• Lead Free Status / Rohs Status: Compliant

To avoid solder wicking over to the via pads during
soldering, it is important to have a solder mask of 4
mil around the pad (NSMD pad). This gives a
diameter of 33 mil for a 25 mil ground pad.
6.5.2.3. Heat dissipation
The thickness of the copper on PCB layers is
typically 34 µm for external layers and 17 µm for
internal
dissipation is not good; high board temperatures
are concentrated around the devices and these fall
quickly with increased distance.
Where possible, place a metal layer inside the
PCB; this improves dramatically the spread of heat
and hence the thermal dissipation of the board.
Figure 6-34. Optimum Layout for Central Ground Ball - top layer
Figure 6-35. Use of Metal Plate for Thermal Dissipation
Metal planes
layers.
This
means
that
thermal
Die
To obtain the optimum ground layout, place the
vias directly under the ball pads. In this case no
local board distortion is tolerated.
The possibility of using the whole system box for
thermal dissipation is very useful in cases of high
internal
temperatures. Bottom side of the PBGA should be
thermally connected to the metal chassis in order
to propagate the heat flow through the metal.
Thermally connecting also the top side will
improve furthermore the heat dissipation.
6-35
illustrates such an implementation.
temperatures
Clearance = 6mil
External diameter = 37 mil
Via to Ground layer
hole diameter = 14 mil
Solder mask
diameter = 33 mil
Pad for ground ball
diameter = 25 mil
connections = 10 mil
Thermal conductor
and
STPC® ATLAS
low
Board
outside
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Figure