Design concept of lead-free SMT circuit board

Up to now, although the country has not put forward special requirements for the design of lead-free SMT circuit boards, and there is no industry standard for SMT circuit boards, it has become a consensus to advocate environmental protection design, and to consider the design concept of SMT circuit boards in terms of material selection, manufacturing, use, recovery cost and other factors.
When realizing the manufacture of lead-free SMT circuit boards, designers should always pay attention to DFM problems, the choice of surface coating of circuit boards, the choice of laminate materials and the consideration of through holes, the choice and reliability of components, and the backward (SN-PB solder and lead-free component SMT chip welding) and forward (lead-free solder and traditional lead component SMT chip processing and welding) compatibility.
  There are various opinions in the industry about the pad design of lead-free SMT circuit boards, some of which are worth discussing. One view is that the design of lead-free pads can be smaller than that of lead pads due to poor lead-free permeability (paving); Another view is that the design of lead-free pads should be larger than that of lead. How to design the specifications and solder boards of lead-free SMT circuit boards? Before producing SMT printed circuit board products, SMT circuit board manufacturers will put forward corresponding suggestions and measures. However, due to the gradual withdrawal of lead technology, the design of lead-free SMT circuit board will be more perfect and more in line with the production requirements.