We have a class 3 assembly we will be doing soon and I was wandering since the fillet heighth required for class 3 is 50% more than class 2, should I have my stencil thickness increased from 6 mil. to 7 mil.? This assembly is made up of 31 mil. pitch qfp's and chip components and sma diodes.What do ya think?
Nearly all of our assemblies have to meet class 3 requirements and we regularly use 5 and 6 mil stencils. If you've got reasonably well controlled processes you won't have any trouble getting class 3 joints on QFPs and discretes.