Managing the Supply Chain: Options for Safe Sourcing of End-of-Life Semiconductors
By George Karalias, Director of Marketing & Communications at Rochester Electronics

During a semiconductor end-of-life event, appropriate and effective supply chain management is no easy task. The primary objective of any procurement professional is to ensure that an uninterrupted supply of parts is available for projected manufacturing schedules as well as for in-field maintenance and repair services. Interruptions in either manufacturing or maintenance can cause significant loss of revenue. However, it is imperative that the procurement of critical semiconductor devices is accomplished while maintaining the integrity of the supply chain. When in need of hard to find mature or EOL semiconductors, what sourcing options do OEMs have to ensure a continuous supply of authentic critical devices?

Unauthorized Distributors
There are many risks in buying components through unauthorized channels. The November 2009 U.S. Department of Commerce, Office of Technology Evaluation, Counterfeit Electronics survey cites unauthorized distributors as the primary source of counterfeit and substandard devices. Unauthorized distributors procure their inventory from a diverse range of suppliers, thus exposing themselves to the potential for stocking substandard products. Sources that are not authorized by the original semiconductor manufacturer typically cannot trace devices back to their points of origin with any degree of certainty. Devices without traceability are not backed by a manufacturer’s guarantee of authenticity, and there is a high probability that the device is counterfeit or substandard. An untraceable device should be an immediate red flag for buyers.
There is no easy way to ensure that the devices purchased through unauthorized sources are genuine or to determine if they have been properly stored and handled to ensure quality and reliability. Improper storage and handling practices can introduce weaknesses and cause early failures due to contamination or electrostatic discharge, as well as assembly problems due to incorrect dry packaging.

Without traceability, a device must be subjected to the fullest extent of legitimate, supplier-approved testing, especially for mission-critical applications. Some unauthorized sources claim testing and screening as protection from counterfeit product; however, more often than not, they do not have the proper equipment or original test programs to guarantee device performance. Testing cannot guarantee a part’s origin, and “spot testing” cannot guarantee an entire lot. Semiconductor testing is rarely performed to the full extent within the gray market, thus the possibility for receiving counterfeit and substandard devices though unauthorized sources remains.

In addition, pricing through unauthorized distributors can be greatly influenced by supply and demand, and, as the supply of obsolete semiconductors inevitably decreases, the price increases, sometimes exponentially.

Authorized Solutions
Authorized distributors are companies that have exclusive rights with an OCM or OEM to market, store, and ship products. Purchasing devices directly from the original manufacturer or from the original manufacturer’s authorized, franchised distributors is the most secure way of ensuring that you will receive only genuine product. Authorized distributors typically only acquire devices directly from OCMs or from other authorized manufacturers. This practice maintains traceability and assures that the inventory has been handled and stored under optimum conditions.

System Redesign
In the event that a critical semiconductor device cannot be procured through an authorized channel, an OEM can choose to redesign an entire system to eliminate the need for the critical semiconductor. However, for many OEMs, a redesign is not a feasible option due to costs associated with engineering man-hours, the purchase of new semiconductor devices for the new design, and production downtime that results from the retesting and re-qualification processes required for the new system. Another downside to system redesign is that there are no guarantees as to how long the original manufacturer will continue to produce the new semiconductor device. EOL announcements are inevitable, and the EOL event could be sooner than expected.

Continuing Manufacturing
Authorized continuing semiconductor manufacturers can use the original manufacturer’s intellectual property (IP) to create new components and provide a continuous supply of qualified, certified, and traceable devices. Authorized continuing manufacturers, such as Rochester Electronics, can extend the life of a semiconductor series by engaging with the original semiconductor manufacturer to acquire the remaining inventory, including packaged devices, finished devices, die, selected intellectual property, tooling, test programs, and test equipment. Authorized continuing semiconductor manufacturers can even use the same packaging design. This transfer of technology ensures that the re-creation of semiconductor devices produces exact replicas of the original part, matching its performance characteristics and physical dimensions. The device can be re-created using the original semiconductor fabrication process at a new foundry.

Authorized Semiconductor Replication
In the event that the original manufacturer’s device no longer exists and the IP is no longer available, authorized continuing manufacturers can replicate the required device with the permission from the original manufacturer. Through its unique Rochester Semiconductor Replication Process™ (SRP™), the contractually licensed manufacturer can reverse engineer a device to re-create and manufacture a pin-for-pin replacement with matched cycle-for-cycle timing. The replicated device is guaranteed to meet the original specifications and perform exactly as the original. Even when the design archive is no longer available, design engineers can build the semiconductor component from scratch. Engineers redraw and/or redesign the device using images from scopes, including a scanning electron microscope (SEM).

Semiconductor replication methodology incorporates an extensive level of physical data extracted from the original manufacturer’s die. Results from an algorithmic analysis of the original die are applied to a proprietary methodology resulting in the re-creation of the original net-list. The replication methodology is dependent upon the structure of the original OEM die, resulting in a lower dependency on the customer data or the accuracy of the original OEM datasheet, which frequently offers only typical propagation delay values. Replication methodology duplicates the internal data paths and their associated propagation delays. Correct-by-design replication of the external behavior of the OEM device requires replication of the internal die structure.

A replicated device is a form, fit, and functional replacement that matches the original semiconductor’s performance. A side-by-side comparison reveals the device is identical to the original. In some cases, engineers can enhance a device’s capabilities and performance characteristics. For example, engineers can redesign the device to meet RoHS compliance, achieve commercial-to-military upgrades, increase radiation-hardened levels, and improve temperature tolerances. After the component is replicated, authorized continuing semiconductor manufacturers can provide a never-ending supply through continued manufacturing. The authorization of the replication and manufacturing of semiconductor devices eliminates any potential legal issues from patent or IP infringement.

Semiconductor Emulation Versus Replication
Semiconductor emulation is usually done without the authorization from the original manufacturer. Without any original IP, the process can only attempt to duplicate the behavior of a target design. The emulated device is more likely to fail over time or not perform completely to the original specifications. Initial emulation design and development costs are typically low, but costs can quickly escalate during the trial-and-error foundry process. And overall costs escalate because of the high in-field failure rate. Fortunately, there is an affordable, proven alternative to emulation: semiconductor replication.

Inventory Management
Through contract, some authorized sources can place devices into bonded inventory for a customer, where the devices are safely and properly stored in dedicated temperature- and humidity-controlled warehouses. Products can then be distributed to specific customers through a customized, comprehensive, scheduled, and managed program. Special product agreements can alleviate many of the problems that arise from unplanned EOL events during the course of a critical system’s existence, including last-time buy and inventory storage costs.

Summary
To keep manufacturing and maintenance efforts on schedule, procurement professionals must find a trusted source of mature and EOL semiconductor devices. Purchasing from unauthorized sources can cause problems that can compound and extend far into the future. Authorized distributors provide semiconductor traceability as well as proper device storage and handling to ensure authenticity and performance. For hard to find mature and EOL devices, the most efficient and cost-effective solution for OEMs is to partner with a licensed continuing manufacturer that offers device re-creation services. Mature and EOL semiconductor devices can be replicated to produce new components that are physically and electrically identical to the original devices. Although there are some companies that claim to provide re-creation services, many only produce an emulation of the product. In addition, replicated devices eliminate the risks of buying substandard, counterfeit, or emulated devices from unauthorized sources.

Rochester Electronics
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