The necessity of lead-free product SMT circuit board design
So far, although the country has not put forward special requirements for the design of lead-free SMT circuit boards, there is no standard for smt circuit boards in the industry, but it advocates environmental protection design, and it is necessary to consider the selection, manufacturing, use, and recycling costs of SMT circuit boards. The design ideas of aspect factors have become everyone’s consensus.
When realizing lead-free SMT circuit board manufacturing, designers should always pay attention to DFM issues, the choice of circuit board surface plating, the choice of laminate materials and through-hole considerations, the choice of components, and reliability issues. And backward (Sn-Pb solder and lead-free component smt chip soldering) and forward (lead-free solder and traditional leaded component smt chip soldering) compatibility issues.
smt processing
There are various opinions circulating in the industry regarding the pad design of lead-free SMT circuit boards, and some of them are worth discussing. One thinks that due to the poor wettability (spreadability) of lead-free, the lead-free pad design can be smaller than the leaded pad; another thinks that the lead-free pad design should be larger than the leaded pad. How to design the specifications and pads of lead-free SMT circuit boards? Before producing SMT printed circuit board products, SMT circuit board manufacturers will give corresponding suggestions and measures. However, due to the gradual withdrawal of lead processes, lead-free SMT circuits The design of the board pad will be more complete and more in line with production requirements.
