Jameco Electronics 2000 ユーザーズマニュアル
60
Rabbit 3000 Microprocessor
5.2.2 Mechanical Dimensions and Land Pattern
The design considerations in Table 5-3 are based on 5 mil design rules and assume a single
conductor between solder lands.
conductor between solder lands.
Table 5-2. Ball and Land Size Dimensions
Nominal Ball
Diameter
(mm)
Tolerance
Variation
(mm)
Ball Pitch
(mm)
Nominal Land
Diameter
(mm)
Land
Variation
(mm)
0.3
0.35–0.25
0.8
0.25
0.25–0.20
Table 5-3. Design Considerations
(all dimensions in mm)
Key
Feature
Recommendation
A
Solder Land Diameter
0.254 (0.010)
B
NSMD Defined Land Diameter
0.406 (0.016)
C
Land to Mask Clearance (min.)
0.050 (0.002)
D
Conductor Width (max.)
0.127 (0.005)
E
Conductor Spacing (typ.)
0.127 (0.005)
F
Via Capture Pad (max.)
0.406 (0.016)
G
Via Drill Size (max.)
0.254 (0.010)
A
B
C
D
E
Land and Trace
Via
G
F