Hello,
My question is regarding the plating used on the CD4013B D-Type Flip Flop chip. Until recently, we have been receiving this chip with silver plating present on the leads but recently, our CM reported the color change from silver to dull looking copper. After some research, we have found that the leads for CD4013BE has a CU NIPDAU Lead/ Ball finish ( per the datasheet). This finish has not changed since the last revision D (March 2005). Revision E also shows the same Lead/Ball finish which is consistent with the dull copper color but does not explain the silver tint on these leads which we have been using for last few years. We have checked multiple sources and found this dull copper lead finish, which rules out a distributor issue. Our question is what changed between silver to copper gold and under what section of datasheet can we see this change under. Please advice. We have attached a picture below to show the two different colors found on the leads, In addition, this dull copper color is present before manufacturing process.