IRDC3899-P1V2

12/8/2011

16

STENCIL DESIGN

Figure 22: Stencil Pad Spacing (all dimensions in mm)

Stencils for PQFN can be used with thicknesses of 0.100-0.250mm (0.004-0.010"). Stencils thinner than

0.100mm are unsuitable because they deposit insufficient solder paste to make good solder joints with the

ground pad; high reductions sometimes create similar problems. Stencils in the range of 0.125mm-0.200mm

(0.005-0.008"), with suitable reductions, give the best results. Evaluations have shown that the best overall

performance is achieved using the stencil design shown in following figure. This design is for

a stencil thickness of 0.127mm (0.005").The reduction should be adjusted for stencils of other thicknesses.