We have covered the key stages of semiconductor lifecycle management (SLiM) for the military/aero component supply chain in previous blogs, and now we'll be looking at several of the key aspects of a successful SLiM program. The preceding articles discussed wafer storage and management and managing fabrication and testing conversion. This article will take a look at extending the supply of key components by undertaking a complete redesign of the product, package, and test programs. (See: Nuts & Bolts of Semiconductor Lifecycle Management, Part 1, Nuts & Bolts of Semiconductor Lifecycle Management, Part 2, and Wafer Storage & Management for Extending Product Lifecycle.)
The primary method for supplying obsolete devices to military contractors is to deliver excess finished goods and product assembled from a wafer die bank. By obtaining rights to, and purchasing, excess stock after the last-time-buy, the typical obsolescence supplier provides support for key program requirements. However, this methodology is limited to the material available at the time wafer fabrication ceases, as many aftermarket suppliers cannot manufacture additional devices.
Once the material from an authorized supplier has been depleted, contractors are forced to search the globe for more, often having to deal with brokers and resellers that may not have the same quality or level of traceability to the fabrication source. This introduces a significant risk as the product may not be authentic and creates the possible introduction of counterfeit devices. In aerospace and defense programs counterfeit devices cause serious risk to the quality and reliability of the end systems, which will cost programs dearly.
The ideal scenario for military programs is to work with a supplier that can indefinitely extend the lifetime of critical devices, completely eliminating the obsolescence issue. The most valuable SLiM provider will have the capability to extend the life of products by executing complete product redesign. This would include the management of a suitable wafer fab facility, test program redevelopment, and completion of the required product qualification.
The new production flow will possess all of the necessary quality controls to meet the stringent requirements of key military and aerospace programs. This strategic SLiM supplier will also be able to obtain full SMD approval, allowing military contractors to purchase the new devices to the exact same specifications as the original device, without the need for modification or redesign of their system.
The ideal SLiM supplier will anticipate the needs of military programs and undertake redesign in advance of the exhaustion of existing material. By working closely with original semiconductor manufacturers, the SLiM supplier will have access to previous purchasing patterns and be able to predict usage rates, enabling a completed redesign effort in time to ensure an uninterrupted supply of devices to the program.
Frequently there are cases where a semiconductor device has not achieved widespread usage, and a single program will need a device redesigned to extend the lifetime of the system. Alternatively, a program may receive orders exceeding the forecasted demand at the time of the last-time-buy on a device, and will need to find a SLiM provider that can redesign that critical component.
The contractor will then need to complete the cost analysis trade-off of a system redesign versus the costs of a semiconductor device redesign. The cost of a device redesign will often be less than that of a system redesign, with the required re-validation and re-qualification of the entire system.
In these scenarios, a successful SLiM supplier will offer custom redesign capability to support specific programs along with the high-quality production capability and sales and distribution channels that meet their needs.