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Misguided QA procedures push up costs and create waste

Posted: 18th November 2015

Sledgehammer to crack a nutIt’s been a long-established principle that properly implemented quality control procedures reduce costs. Production yields are improved, product performance and reliability are enhanced, and customer satisfaction grows. It’s perhaps one of the lessons that Western electronic equipment manufacturers learned from their Japanese counterparts in the 1970s. But the key phrase here is “properly implemented” and in recent years one particular edict by some QA managers is simply a case of using a sledgehammer to crack a nut – this particular nut being the issue of component date codes.

A significant but growing minority of QA departments, including those of some distributors, will not accept components that are more than two years old. This is perhaps understandable when talking about aluminium electrolytic capacitors or certain types of battery, where internal electrochemical reactions mean that the components are deteriorating from the moment they come off the production line. However, there is no technical justification whatsoever for applying this rule to all component types. It’s like saying that the shelf life of fresh mackerel is the same as that of canned pickled herrings!

The issue is not entirely a new one. Back in 2002, the National Electronic Distributors Association (NEDA), after consultation with 13 major component manufacturers and distributors, published a white paper that recommended, “The NEDA member component manufacturers and their authorized distributors recommend that general date code restrictions be eliminated from purchase order requirements for electronic components.” It came to this conclusion with the proviso that component makers and their authorised distributors have in place procedures to deal with exceptions. Such exceptions include where a product design
has proven to be intolerant to lot-specific variations of parts that are still operating within the manufacturer’s specification, where customers have suspected component variation issues that could be related to the age of components, or where there are other specific technical requirements. In other words, the recommendation is that the supply chain manages the very few exceptional circumstances that are critical with respect to component date codes, rather than imposing unnecessary blanket rules for all components. In addition, there are various other documents from leading chipset/IC manufacturers that come to the same conclusion, including Freescale, Maxim and Texas Instruments whilst Digi-Key confirm their policy alignment with NEDA.

This issue is important because date code overkill policies damage competitiveness at a time when, perhaps as always, businesses are under pressure to minimise costs without compromising quality. If component makers have to scrap parts as soon as they are more than 2 years old, it creates waste, which is environmentally irresponsible, and adds cost, which has to be passed on to customers. It may also mean that inventory is not available at the time it is needed, leading to manufacturing delays, which adds further cost and inconvenience.

IQD’s products are designed and manufactured to provide many years of reliable performance in customers’ circuits. The vast majority of our products are delivered to customers within two years of manufacture. However, on the very rare occasions that we do ship product that was manufactured more than two years previously, the product will have been stored in an appropriate environment, solderability tested (to IEC-68-2-20 for thru-hole products and CECC 00 802 for SMD) and is still be covered by IQD’s normal guarantee.

Supported by evidence of 40+years experience that quartz based frequency products suffer no detrimental effects in performance from an extended shelf life, customers need not have any concerns about accepting such products, in line with the recommendations of other leading component manufacturers.

In other words, buying IQD crystals and oscillators that are more than two years old involves no compromise whatsoever with respect to the quality or performance of these components.