These days, component packaging is often based on high volume, mobile devices. The money simply may not be there for multiple form factors (e.g. DIPs and larger SMT packages). The same goes for cost structures. At the high volumes, any fraction of cent can make a difference.
The specific chip may not be a high volume chip, but that manufacturer (or the package manufacturer) likely sells enough of that package type to be concerned about micro costs. Personally, though, I think the mark every five pins is an awesome idea.
I suspect that cost is really the driving factor behind the removal of markings on SMT components. It's not just the ink. It's a completely separate manufacturing step. That extra step can be a significant part of the component cost.
Absolutely, and while we're at it why don't high pin count IC's have a mark in the molding every 5 or 10 pins? Amortised across the No. of chips that come out of a mold die it would be near zero additional cost
The notion that the blind shall lead the blind is simply unacceptable to me as a customer. It's time to take a stand and tightenen up our contract/order wording to explicitly require labeling. This is an example of penny wise for the component manufacturer and dollar foolish for the customer. Once orders to the guilty manufacturers dry up, they'll get the message or rightly go belly up. We must enforce, "The Customer is Always Right."
I hear and understand about an undocumented change and I have had even Vishay pull something like this on Digi-Key stocked parts, but changing lead diameters on through-hole inductors (they made 'em bigger, great for board designers when the data sheet and the acutal part don't match PHYSICALLY).
I would simply change the supplier of the resistors. It seems that Visahy Dale, Rohm, Panasonic, and Stackpole are likely to have a substitute for your Yageo part, and the 0603s and larger are going to be marked if my experience is any indicator.
Regarding marking capacitors, tantalums in molded housings are generally marked. The conformally coated Vishay (orange) tantalums are often not marked, and most ceramics are not marked. It is my understanding that part of this is the design of the ceramic capacitors and a history with the military from many years ago, when marking the parts actually degraded the reliability of the capacitors because the ceramic was fragile and thin on outer layers. Today, coating one surface of the ceramic chip and laser marking would seem quite reasonable, but until accepted as the "norm" would likely bring a cost penalty. For me, the cost penalty does not seem like much since most of what I design only makes at most 10K-20K boards of a type per year, and the costs associated with assembly are often much greater than the cost of purchase for chip passives. I agree that having all components marked would be a great help in inspection and trouble-shooting.
@Etmax: Often I get parts that are not what's on the label and so I now check all parts received before they are loaded on the board.
It just blows my mind that every part isn;t identified in some way -- even the smallest parts would support colored dots -- also it wouldn't be beyond the bounds of possibility to have different colored packaging materials -- one for resistors, one for capacitors, and one for ICs...