System and method for decreasing ESD damage during component level long term testing

Abstract

A method is disclosed for minimizing damage from electrostatic discharge (ESD) during long-term testing of electronic components and assemblies. The method includes conducting a stress-test, during which a protection circuit is engaged, which shields components and assemblies from ESD. Then at least one functional test is conducted, at which time, the protection circuit is disengaged. Also disclosed is a system for conducting long-term testing of electronic components and assemblies while providing protection from ESD. The system includes a testing circuit for providing current to the components and assemblies during the long-term testing which includes at least one stress-testing phase and at least one functional testing phase. Also included is a protection circuit for protecting the components and assemblies during said stress-testing phase of said long-term testing. A switch is included for disengaging the protection circuit from the components and assemblies during said functional testing phase of said long-term testing.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates generally to long-term testing of components and more particularly to protecting components trom Electrostatic discharge (ESD) during long-term testing. [0003] 2. Description of the Prior Art [0004] Long-term testing has become more and more important as competition in the electronics field becomes ever more intense. A company's reputation for reliability is a major factor in many customers' purchasing decision. Reliability, in turn, comes largely from improved procedures based on data gathered during long-term testing of components. During these long-term tests, manufacturers can gather important information on modes of failure, and specific component performance, which can provide valuable feedback to improve devices and components. [0005] Unfortunately, long-term testing can expose components to damage from electrostatic discharge (ESD, here ESD is inclusive of discharge events resul...

AI Technical Summary

Benefits of technology

[0010] A preferred embodiment of the present invention is a system and method for minimizing damage from electrostatic discharge (ESD) during long-term testing of electronic components and assemblies. The method includes conducting a stress-test, during which a protection circuit is engaged, which shields said components and assemblies from ESD. Then at least one functional test is conducted during said stress-test, at which time the protection circuit is disengaged.

[0012] It is an advantage of the present invention that electrical components and assemblies can be given long-term testing without producing excessive failures which produce unnecessarily low production reliability projection.

[0013] It is another advantage of the present invention that higher quality, more durable products can be produced.

[0014] It is yet another advantage of the present invention that electronic components and assemblies can be protected from ESD, yet still give accurate and reliable testing results during functional testing.

[0015] It is still another advantage of the present invention that improved two-stage testing may be practiced without subjecting components and assemblies to unrealistic levels of ESD.

Problems solved by technology

Unfortunately, long-term testing can expose components to damage from electrostatic discharge (ESD, here ESD is inclusive of discharge events resulting from electromagnetic interference (EMI), for example), that is generated in amounts not possible during realistic everyday operation by the consumer.

In particular, it has been well known that assemblers or production personnel who shuffle their feet while walking across rugs may generate a static charge that can damage components.

Disk drive heads are often damaged due to ESD during a long term thermal or other reliability testing.

The test may run as long as 1000 hours and it is difficult to keep the heads from any source of ESD for such long time.

Unfortunately, diodes provide protection only up to 700 mV but disk heads generally are destroyed if 700 mV is applied in 1 nS or longer time constant.

In addition, capacitors offer essentially no protection from slow transients.

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