STPCE1HDBI STMicroelectronics, STPCE1HDBI Datasheet - Page 78

• Manufacturer Part Number: STPCE1HDBI
• Manufacturer: STMicroelectronics

Specifications of STPCE1HDBI

• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Processing Unit: Microprocessor
• Operating Supply Voltage (min): 2.45/3V
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 2.7/3.6V
• Package Type: BGA
• Screening Level: Industrial
• Pin Count: 388
• Mounting: Surface Mount
• Rad Hardened: No
• Lead Free Status / RoHS Status: Supplier Unconfirmed

DESIGN GUIDELINES
When considering thermal dissipation, one of the
most important parts of the layout is the
connection between the ground balls and the
ground layer.
Considering only the central matrix of 36 thermal
balls and one via for each ball, the global thermal
resistance is 2.9°C/W. This can be easily
improved using four 12.5 mil wires to connect to
The use of a ground plane like in
even better.
78/87
This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
Figure 6-25. Recommended 1-wire Power/Ground Pad Layout
Figure 6-26. Recommended 4-wire Ground Pad Layout
Figure 6-27
Release 1.3 - January 29, 2002
is
A 1-wire connection is shown in
use of a 8-mil wire results in a thermal resistance
of 105°C/W assuming copper is used (418 W/
m.°K). This high value is due to the thickness (34
µm) of the copper on the external side of the PCB.
the four vias around the ground pad link as in
Figure
global resistance for the 36 thermal balls of 0.5°C/
W.
Pad for ground ball (diameter = 25 mil)
Solder Mask (4 mil)
Connection Wire (width = 12.5 mil)
Via (diameter = 24 mil)
Hole to ground layer (diameter = 12 mil)
4 via pads for each ground ball
6-26. This gives a total of 49 vias and a
1 mil = 0.0254 mm
Figure
6-25. The