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Project Completion: Static Event Detector (SED) Initiative

The objective of this project was to determine the feasibility of developing a Static Event Detector (SED) Health Monitoring System. This system would alert inspectors or equipment operators to an electrostatic discharge (ESD) event that may have inflicted latent or catastrophic damage to critical electronic components resulting in a weapons system’s degraded performance. A SED is a device that detects the passage of an electrostatic discharge event. It can be as simple as a fuse or a metal-oxide semiconductor (MOS) device, both are single use devices. A magneto-optic static event detector (MOSED) is a subset of SEDs. It is resettable and thus reusable and is the type of SED developed during this project.

A novel optical reader has been developed to remotely interrogate individual MOSEDs. MOSEDs can be strategically placed within an electrostatic sensitive system and used to identify the modules or components potentially damaged. Confirmation of the static discharge event would trigger special actions or tests to verify the operational integrity of the weapon system under evaluation. A static sensitive test circuit (SSTC) was also developed to evaluate the efficacy of this new health monitoring system.

The NCMS-CTMA project feasibility development efforts resulted in the successful demonstration of all required hardware and software needed to implement the prototype MOSED evaluation effort. New detector designs compatible with the proposed reader were successfully fabricated at VCD Technologies. These designs contained special electrode patterns that allowed the detector to read ESD events regardless of polarity. A MOSED reader was designed and fabricated by Pukoa Scientific that is capable of autonomous operation; human interpretation of the state of the MOSED is not required. Reset devices were created to return the MOSED to a neutral state. The Beta Site demonstration validated device and system performances.

Benefits
The Tobyhanna Army Depot potential cost element assessment provided at the onset of this project was estimated to be $1.5 M/year to about $2.5 M/year, based on estimated rework cost parts and labor generated from the 10% of the unprotected ESD events that can cause damage to ESD sensitive equipment. Recent reassessment of cost savings elements is as follows:

• Digital integrated circuits workload has increased somewhat and burdened labor rate slightly

• Number and replacement costs of integrated circuits and the number of integrated circuits that need changing to determine faults have also increased

• New assessment is estimated close to $2.5M/year.

Timely detection of ESD events can benefit the reliability and lifecycle of electronic devices as follows:

• Depots and manufacturers can improve on assembly processes that historically have damaged, destroyed or degraded electronic devices.

• End users can improve their handling of ESD sensitive devices, resulting in improved readiness in the field.

• Depot repair facilities can improve their cycle time on field returns thereby providing added value to their repair/replacement functions.