Marvell PXA27x Processor Family

PXA27x Processor Family
Design Guide
2.2.3.1 VF-BGA Escape Routing
This section documents the method of VF-BGA routing along with the recommended dimensions.
Table 3:
Feature
PCB Dimensions for Copper-Defined Land Pads
.5 mm
BGA
Finished 2
.5 mm
BGA
Designed
A: Land Pad Size .254
(.010)
B: Solder Mask Opening .381
(.015)
C: Typical Trace Width .1016
(.004)
D: Reduced Trace Width Between Land Pads .0635
(.0025)
E: Typical Micro Via (Via-in-Pad) Drill Size .102
(.004)
.279
(.011)
.381
(.015)
.127
(.005)
.0889
(.0035)
.102
(.004)
NOTE:
1. All dimensions are in mm (inches).
2. Finished sizes accounts for copper etch.
On the two inner rows of the VF-BGA, route down the signals from the top layer to the inner PCB layers for routing
away from the package. See Figure 8 for illustration of the PCB escape routing using the VF-BGA method.
Figure 8:
PCB Escape Routing for Copper-Defined Land Pads
Recommended Style:
Copper Defined Land Pads
A: Land Pad Size
B: Solder Mask Opening
C: Typical Trace Width
D: Reduce Trace Width
Between Land Pads
Trace on Layer 2
Top View
E: Typical Micro Via (Via-in-Pad) Size
Land Pad
Solder Mask
Side View
Doc. No. MV-S301207-00 Rev. A
Page 32
Copyright © 2009 Marvell
April 6, 2009, Released