Die Banking: Why Recovery Time Matters
Nothing is meant to stay in storage forever, even if sometimes the timetable is so extensive it may sometimes seem that way. Even radioactive nuclear waste storage, which must remain stored and buried for at least 10,000 years, is not meant to be indefinite.
By definition, storage is a three-part process: the implementation of the act, the waiting period, and the extraction. When making the decision to store any inventory crucial to a company’s long-term goals, valuing one of these parts over the other can ultimately prove costly. Secure storage is part of the equation, but if the inventory is not possible to retrieve in a timely, efficient manner, the strain it places on a supply chain can potentially negate the savings secure long-term storage proposes in the first place.
The technology involved in die and wafer banking has improved by leaps and bounds in recent years, offering electronics OEMs an avenue around many of the disruptions that have plagued the industrial sector of late – unexpected component obsolescence, allocation, price inflation etc. – while saving significant costs at the point of assembly. A raw, uncut wafer in proper packaging supplied on a tape-and-reel has a nearly indefinite shelf life – provided, of course, the storage temperatures and moisture-sensitive levels (MSL) remain optimal throughout the process. Nitrogen-infused cabinets have made these strict specifications attainable for OEMs who can afford the technology, but with a very important caveat: Once a portion of the inventory is retrieved, the cabinet must be given time to restore conditions until another retrieval can be made.
This time varies depending on the equipment in question, but a standard wafer recovery time is approximately 20-30 minutes. As a result, handlers can only retrieve inventory, at most, three times per hour, which can significantly affect a supply chain’s ability to operate efficiently if not fully accounted for.
It’s only recently that cabinet manufacturers have begun to address this limitation with new technologies. ECD, for example, is the first company to introduce ECD dry cabinets with SmartDRY™ technology. Instead of relying on nitrogen which cannot maintain a relative humidity below 6 percent, ECD SmartDRY™ cabinets rely on a volcanic compound called zeolite capable of maintaining a relative humidity of an astounding 0.5 percent – with a recovery time of only three minutes. As a result, handlers can retrieve inventory up to 12 times per hour, all but eliminating one of the most concerning issues associated with die and wafer banking. OEMs can have nearly full access to all of their inventory, when needed, without compromising the entirety of their investment.
So, when making a decision regarding which supply chain partner to trust with your raw die and wafer, pay attention to the recovery time their tech allows. Will they be able to retrieve your inventory in a timely fashion if production suddenly accelerates? If not, then it might be worth seeking out a partner with die banking capabilities capable of meeting or exceeding your fulfillment standards.
OEMs should choose partners who are able to adapt to their needs – not the other way around. For more information on Partstat’s die and wafer banking capabilities, click here.