AT88RF1354_09 ATMEL [ATMEL Corporation], AT88RF1354_09 Datasheet - Page 39

• Manufacturer Part Number: AT88RF1354_09
• Description: 13.56 MHz Type B RF Reader Specification
• Manufacturer: ATMEL [ATMEL Corporation]

8547B–RFID–3/09
The fillet formation is also a function of the PCB land size, the printed solder volume, and the package standoff height.
Since there is only limited solder available, higher standoff (controlled by the paste coverage on the thermal pad) may
not leave enough solder for fillet formation. Conversely, if the standoff is too low, large convex shape fillets may form.
This is shown in Figure D-7. Since center pad coverage and via type were shown to have the greatest impact on the
standoff height, the volume of solder necessary to create optimum fillet varies. The package standoff height and the
PCB pads size will establish the required volume.
Figure D-7. Solder fillet shape for various standoff heights
Large PCB Pads, 81% Paste Coverage,
37% Paste Coverage, Plugged Via,
50% Paste Coverage, Plugged Via,
1.4 mil Standoff
2.9 mil Standoff
Plugged Vias
13.56 MHz Type B RF Reader Specification
Small PCB Pads, 81% Paste Coverage,
81% Paste Coverage, Encroached Via,
37% Paste coverage, Encroached Via,
0.6 mil Standoff
2.1 mil Standoff
Plugged Vias
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