Data processing: measuring – calibrating – or testing – Testing system – Of circuit
Reexamination Certificate
2001-10-11
2004-07-20
Hoff, Marc S. (Department: 2857)
Data processing: measuring, calibrating, or testing
Testing system
Of circuit
C702S081000, C702S118000, C324S760020
Reexamination Certificate
active
06766267
ABSTRACT:
BACKGROUND OF THE INVENTION
1 . Field of Invention
The invention relates to methods and systems for performing stress testing of equipment. The invention also relates to active and passive stress testing using modular design and robust data collection that is adaptable to a variety of equipment.
2 . Description of Related Art
It is common to subject integrated circuits (IC) to various stresses to ensure reliability. Specifically, an IC is typically subjected to high temperatures for an extended period of time. This process is called “bum-in” testing in the art and identifies marginal devices likely to succumb to such stresses in the field.
Various systems and methods have been designed to perform burn-in testing of integrated circuits and computer components. Many of these conventional solutions focus on specific adapters and hardware that permit high-volume bum-in testing of specific equipment.
For example, Slocum (U.S Pat. No. 6,097,201) discloses a system of stackable test boards in which a large number of integrated circuit boards may be mounted. Each of Slocum's test boards includes a contactor region that permits test signals to be routed to the individual integrated circuit boards. As such, Slocum's system is specifically designed to perform high-volume burn-in testing of specific components (integrated circuit boards).
Leung (U.S. Pat. No. 5,798,653) utilizes a special-purpose burn-in controller located within the burn-in oven to “exercise” an integrated circuit (IC) by toggling a high percentage of the switches within the IC.
Leung also illustrates the conventional thinking of burn-in testing which is to select a statistically significant sample of the product (IC's in this case) which are then subjected to burn-in testing. Like Slocum, Leung's system performs a dynamic test in which input stimuli are applied to the ICs to exercise or toggle the electrical circuit nodes of the IC.
Leung performs two types of dynamic burn-in testing on these sample IC's including an infant mortality burn-in and a longevity qualifying burn-in which mainly differ in the amount of time in which the IC's are subjected to the age-accelerating burn-in test. A simple data set is collected from these tests, which includes how many ICs succumb to infant mortality.
The flexibility of conventional stress testing systems is quite limited. Moreover, the number testing circuits matches the number of IC boards being tested thus requiring duplicative testing hardware. Moreover, the data collected by conventional system is quite rudimentary. Thus, there is a need in the art that solves these and other deficiencies in conventional stress-testing systems.
SUMMARY OF THE INVENTION
The present invention brings revolutionary concepts to the field of stress testing: utilizing a virtual oven, sharing test equipment, and logically grouping components and modules to be tested provides many distinct advantages over the prior art.
In general, the inventive systems and methods solve the problem of massive manual management of the following: a) process control, b) data, c) active signal controls, and d) product performance verification for stress testing. This goal was accomplished by designing, developing, and making operational an Automated Monitoring System (AMS). AMS communicates to modules and test equipment that are undergoing and performing stress testing as well as collecting the data automatically.
Stress testing according to one aspect of the invention includes exposing operating equipment/modules to thermal stress (or other stressor(s)) over a long (e.g. 48 hour) period of time including an (e.g. 24 hour) active test such as a bit error rate test (BERT) for optically tested modules (e.g. transmitters, receivers, remodulators, selectors, transceivers, variable optical attenuators, and amplifiers). The stress tests may also involve introducing noise to the test signal and/or degrading the test signal strength. The invention is capable of testing a wide variety of other components including electronic, opto-electronic, and optical components.
The inventive stress-testing process is a critical component of the manufacturing flow for producing reliable modules because the invention:
Reveals module damage due to handling (e.g. electrostatic discharge or other handling related damage).
Virtually simulates field conditions over a broad range of temperatures, operating conditions, and signal conditions.
Deliberately ages the product so as to eliminate substantially all early life failures from the product shipped to the customer.
More specifically, virtual oven for stress testing a plurality of modules includes a logical group of modules loaded into an environmental stress screening room wherein an environmental stress parameter of the environmental stress screening room changes over time; a test equipment operatively connected to the modules of said logical group, said test equipment generating a test signal and capable of performing an active test of at least one of the modules of said logical group at a time; and a controller operatively connected to said test equipment and to said logical group of modules; said controller receiving results of the active test performed by said test equipment.
The modules may also include sensors or other devices for measuring parameters of the module and the controller may receive passive test measurement values from these sensors. In this way, a passive test of the modules may be performed independently of and simultaneous with the active testing. The results of the active test and the passive test measurement values for each of the modules are associated with the module and stored in a database.
Furthermore, the controller may send a command to at least one module of the logical group to, for example, place that module in a desired operational state, exercise the module, or otherwise assist in the testing regime.
Moreover, a network may be used to operatively connect the test equipment with the controller, the memory device, and each of the modules of the logical group. The invention also includes a system of virtual ovens that may be connected via a network.
The inventive methods for stress-testing a plurality of modules includes designating a logical group of modules in an environmental stress screening room wherein an environmental stress parameter of the environmental stress screening room changes over time; generating a test signal; supplying the test signal to at least one of the modules of the logical group to subject the at least one module to an active test thereof, and receiving results of the active test from one of the modules of the logical group with a test equipment.
The method may perform a series of tests of the logical group modules on a time-share basis with the test equipment. In addition, the method may further include receiving passive test measurement values from at least one of the modules of the logical group; analyzing the passive test measurement values and the active test results; and displaying results of said analyzing step.
Moreover, the invention encompasses a method of asynchronously conducting stress testing on a plurality of groups modules including a first and second logical groups of modules. This method asynchronously initiates testing of the first and second logical groups of modules; tests the first logical group of modules with the first test equipment; and tests the second logical group of modules with the second test equipment, wherein each of said testing steps respectively includes said generating step, said supplying step, and said receiving step.
The inventive methods also include receiving passive test measurement values from at least one of the modules of the logical group; and storing results of the active test and the passive test measurement values for each of the modules in the database.
Moreover, the modules comprising the logical groupings are not necessarily physically adjacent to one another.
The inventive virtual oven system may also utilize an inventive database. In particular, the data
Dar Iqbal
Floyd John
Humberson Jerome
Obradovic Mila
Barbee Manuel L.
Cammarata Michael R.
Ciena Corporation
Hoff Marc S.
LandOfFree
Automated monitoring system, virtual oven and method for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automated monitoring system, virtual oven and method for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automated monitoring system, virtual oven and method for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3188233