• Stencil parameters for the EP (Exposed Pad) such as aperture area ratio and the fabrication process have a significant impact on paste deposition. Inspection of the stencil prior to placement of the LLP (WQFN) package is highly recommended to improve board assembly yields. If the via and aperture openings are not carefully monitored, the solder may flow unevenly through the EP. Stencil parameters for aperture opening and via locations are shown in the RTV package drawing.
• The EP of the package should be connected to the ground plane through a 3x3 via array. These vias are solder-masked to avoid solder flowing into the plated-through holes during the board manufacturing process. Details about via dimensions are also shown in the RTV package drawing.

More information on the QFN style package is provided in QFN and SON PCB Attachment.