Addressing Two Primary Concerns Associated with Die and Wafer Banking

By Logan Wamsley

When making the decision to implement ASICs into their product designs, original equipment manufacturers (OEMs) often look at the benefits ASICs can offer their supply chain. Tighter obsolescence management procedures, more secure IP protection, increases in processing speeds and efficiency, and significantly reduced assembly and packaging costs are just a few of the advantages ASICs provide – and OEMs across industries ranging from healthcare to telecommunications to aerospace are taking notice.

But despite these many benefits, OEMs must also account for the additional challenges ASICs can bring to the manufacturing process. If underestimated, the costs associated with properly banking, handling, and fulfilling ASICs in their basic die and wafer form can easily mitigate any savings they might provide. For smaller-scale manufactures, the working capital investment associated with putting a new infrastructure in place suitable for die and wafer banking could prove too daunting to realistically consider.

Whether it’s done in-house or through an ISO certified supply chain partner, these are the two most important factors to keep in mind when preparing your supply chain for die and wafer banking:

Moisture Sensitivity

Most electronic components are sensitive to moisture, but secure packing and proper storage in climate-controlled warehousing is usually sufficient for them to function at the time of assembly. Raw die and wafers, however, while capable of being stored years beyond a generic component’s last time buy date, require a great deal more care regarding relative humidity.

According to Cypress Semiconductor Corporation, banked die and wafer should be stored at temperatures between 18°C and 24°C, with a maximum relative humidity of less than 30 percent, in a vacuum sealed bag. For most supply chain partners that offer die and wafer banking services, storage at 6-10 percent relative humidity is the norm with the use of nitrogen-enriched dry cabinets. The dryer the storage climate is, the better.

To further aid customers who wish to guarantee long-term business continuity with their obsolescence management strategy, Partstat has opted to go beyond the industry standard by offering SmartDRY™ technology. Designed specifically to store components with low Moisture Sensitivity Levels, these desiccant ECD dry cabinets intelligently maintain a relative humidity of 0.5 percent through the use of zeolite – a natural clay-like compound that comes from volcanic earth deposits and exhibits humidity control qualities far superior to nitrogen.

ESD Sensitivity

Die and wafers are also extremely sensitive to electrostatic discharge (ESD) which can occur almost anywhere within a supply chain, including during any point where a handler must come in direct contact with the inventory. To mitigate contamination, it’s important for OEMs to verify that partners adhere to strict storage and handling processes as outlined by JESD625. This includes rigorously grounding workstations with the use of placemats, wrist straps for handlers, and ESD lab coats; reducing high-static voltage areas to less than 1,000 volts; and using the latest air ionization techniques to neutralize the static charge on insulated and isolated objects.

As an added protective measure against electrostatic discharge, Partstat offers all die and wafer banking customers the use of our modular vault. A supply chain industry first, this vault features Fire Rated Class 350 Certification, ceramic panel construction rated “best in class” for electronic component storage, a clean agent fire suppression system, and full magnetic field protection – all of which can guarantee the success of any OEM obsolescence management strategy.

Moving Your Supply Chain Forward

The die and wafer banking option of Partstat’s Custom Storage & Fulfillment Solution was designed based on the feedback we have received from hundreds of customers across the globe. After careful analysis, we learned that in such a competitive marketplace OEMs and EMS providers alike desire business continuity in all phases of their supply chain, from last time buy transactions to long-term inventory fulfillment – and we are proud to say that our die and wafer banking more than exceeds the high expectations we place on ourselves.

What would you like to see in a supply chain partner? Let us know!