ESDAXLC4-1BF3 Datasheet, PDF (6/10 Pages) STMicroelectronics – Single line extra low capacitance TVS

PCB recommendations
Figure 12. Flip Chip tape and reel specification
0.20 ± 0.05
2.0 ± 0.05 4.0 ± 0.1
ESDAXLC4-1BF3
Ø 1.55 ± 0.05
0.43 ± 0.1
All dimensions in mm
0.57 ± 0.05
2.0 ± 0.1
User direction of unreeling
4
4.1
Note:
PCB recommendations
Design
For optimum electrical performance and highly reliable solder joints, STMicroelectronics
recommends the PCB design recommendations listed in Table 3.
Table 3. PCB design recommendations for solder bar pitch 400 µm
For NSMD PCB
non solder mask defined
Oblong pad: 370 x 180 µm
– Micro via SSBU allowed
– Micro via SBU to be avoided
– Micro via SBU filled (under qualification)
Track:
– Only one track per pad
– Maximum track width = 100 µm
Track layout must be symmetrical to the die axis (to homogenize stress
and welding attraction during reflow assembly)
For SMD PCB
solder mask defined
Oblong pad:
– Micro via SSBU allowed
– Micro via SBU to be avoided
– Micro via SBU filled (under qualification)
PCB Pad Finishing
Cu – Ni (2-6 µm) - Au (0.2 µm max)
A gold layer finishing on the PCB pad that is too thick (0.2 µm maximum) is not
recommended (low joint reliability).
6/10
Doc ID 018522 Rev 2