73M1866B-IFX Maxim Integrated Products, 73M1866B-IFX Datasheet - Page 11

• Manufacturer Part Number: 73M1866B-IFX
• Description: KIT EVALUATION FOR 73M1866B
• Manufacturer: Maxim Integrated Products

Specifications of 73M1866B-IFX

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AN_1x66B_003
73M1866B/73M1966B Schematic and Layout Guidelines
Figure 9: 73M1866B Reference PCB Top View
Figure 10: 73M1866B Reference PCB Bottom View
Exposed Bottom Pads on 73M1x66B QFN Packages
The 73M1866B and 73M1966B QFN packages have exposed pads on the underside that are intended for device
manufacturing purposes. These exposed pads are not intended or needed for thermal relief (heat dissipation)
and should not be soldered to the PCB. Soldering of the exposed pad could also contribute to “QFN float”, where
the outside pad connections are compromised because of the package sitting higher than the optimum height due
to excess solder on the center pads. There are ways to avoid this using a segmented stencil for the solder
application, but since there isn’t any benefit to soldering the pad, leaving it unsoldered is advised. Also avoid any
PCB traces or through-hole vias on the PCB beneath the exposed pad area.
Rev. 3.5
11