New Contributor
Super ContributorHi,
stencil parameters are usually set depending on the components used on a PCA. Thickness is selected according to big pad components, e.g. power transistors or power IC. With a general purpose stencil of 100 µm, the EQFP 64 exposed pad won't need to be divided into smaller squares. If your stencil is thicker, you'll probably use segments.
You'll notice that exposed pad to PCB clearance can vary between 50 and 150 um according to datasheet, it's impossible to dispense solder paste exactly. Fortunately the only requirement is to have the pad safely connected, there's no massive heat dissipation of the part.
Another question is how to implement ground vias. You have the choise between VIPPO (via-in-pad plated over), thin open vias in pad (e.g. 200 µm) or vias around the pad.
