The Challenge of Die and Wafer Banking: Solved

By Logan Wamsley

As technology in the electronics industry continues to evolve and accelerate at an unprecedented rate, manufacturers are being forced to adapt their tried-and-true supply chain models to confront this new reality – or risk falling behind in the race to produce the cutting-edge products consumers expect.

In their efforts to combat obsolescence, for example, many manufacturers are increasingly turning to the use of Application Specific Integrated Circuits (ASICs) in their designs. Unlike a general circuit designed to perform a variety of roles, ASICs are custom manufactured to fulfill a very specific, unique role for a single product. This characteristic offers numerous benefits for the manufacturer including smaller component sizes, faster processing speeds, greater IP protection, and significantly reduced costs per unit.

To take full advantage of these features, however, equipment manufacturers must also understand how to properly store them.

What is Die and Wafer Banking?

Unlike an assembled component such as a microprocessor or random access memory chip, ASICs can be stored, or “banked”, in die and wafer form – the most basic elements of a microchip. Having a critical component in such a raw state can help equipment manufacturers avoid upfront packaging, assembly, and testing costs typically charged by OCM partners while still maintaining sufficient inventory for their product’s entire life cycle.

But the metal composition of raw die, compared to an assembled microchip, is incredibly sensitive to oxidation – and to function properly at the time of assembly, it must be stored in accordance with very strict, highly regulated humidity specifications.

Die is also particularly sensitive to electrostatic discharge (ESD). If handlers do not take the proper precautions, the metal’s ability to carry an electrical current can significantly degrade over time.

When facing these storage challenges, manufactures confront an inherent contradiction: If ASICs require such a significant investment of new banking procedures, does that negate the front-end savings that made ASICs so attractive in the first place? This is the central issue of die and wafer banking that supply chain partners like Partstat seek to resolve with a commitment to comprehensive, meticulous, and cost-effective die and wafer banking solutions.

The Banking Process at Partstat

The first and most vital element of any proper die and wafer banking infrastructure is traceability. From the raw materials’ point of origin to their final destination within an assembled product, the banker must have the ability to easily access, monitor, and control the flow the inventory in accordance with the manufacturer’s needs. Partstat provides this by offering customers a dedicated staff with extensive training in the verification, shipping, inspection, and packaging protocols regarding ASICs in all levels of the supply chain.

Once the critical inventory is in Partstat’s possession, our focus then turns to the banking process itself. To combat oxidation, die manufactures recommend wafers be stored in a climate-controlled environment capable of maintaining at least 6-10 percent relative humidity.

Partstat, by contrast, goes an extra step by offering a new innovation called SmartDRY™ technology. Designed specifically to store components with a low Moisture Sensitivity Level (MSL), these desiccant ECD dry cabinets intelligently maintain a relative humidity of 0.5 percent – far below the IPC standard. This is accomplished through the use of zeolite – a naturally occurring clay-like compound that comes from volcanic earth deposits and exhibits humidity control qualities far superior to nitrogen, which has long the industry-standard involved in die and wafer banking.

In addition to unparalleled humidity control, SmartDRY™ cabinets prevent ESD by using durable electrically conductive powder paint surfaces over steel construction. As an added security measure, all of these cabinets are also stored in Partstat’s one-of-a-kind vault which 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.

Taken together, all these aspects of Partstat’s die and wafer banking infrastructure grants customers a level of business continuity that no other supply chain is capable of matching – and we are proud to offer them all as part of our Custom Storage and Fulfillment Solution.