Tracewell Systems

Design Verification

Tracewell Electronics performs complete design verification testing (DVT). Using our extensive testing and laboratory facilities, our professional engineering staff can design, troubleshoot and qualify your product at any stage of its lifecycle.

HALT

Whether done independently, or as part of the DVT testing, Tracewell can perform Highly Accelerated Life Testing (HALT). During this test, the product is driven beyond its normal operating conditions of temperature and vibration and brought to the point of failure. HALT testing is a requirement for all designs with the goal of forcing out latent failures early in the product lifecycle, prior to the start of production. Of particular interest would be those which are failing due to inadequate derating or substandard design. Failures are analyzed and, if necessary and/or economically feasible, will be eliminated from the design. The test/cycle continues until it is no longer necessary or reasonable to proceed. This process enhances the durability and overall reliability of the product.  As part of normal production, the HALT profile can be reduced to a production level test, Highly Accelerated Stress Screening (HASS). HASS can be performed continually or on an audit basis to monitor process issues.

First test

First test is a combination of Hi Potential safety test and full load functional test. These test are done by program-controlled, automated test equipment, which records all test results in the quality database by serial number for each unit tested.

Burn-In

Units are run at high ambient temperature  (50° C) while being power cycled for a period from 8 to 96 hours. All outputs of the units are monitored during this test and the time to failure is recorded in the quality database for each unit by serial number. Other levels of burn include Environmental Stress Screening (ESS) and Highly Accelerated Stress Screening (HASS).  ESS is a thermal stress, of ~1 degree C/minute, while the unit is operational and being monitored. HASS is a combination of thermal and vibration, of ~ 1 degree C/Second and a vibration of 50G’s max, while the unit is operational and being monitored.

Final test

Final test is designed to detect any changes to units during burn-in. It is a complete Hi Potential safety test and full-load functional test. This test is done by program-controlled, automated test equipment, which records all test results in the quality database by serial number for each unit tested. A quality inspection of each unit is performed after the test to assure all quality checks have been performed and that unit appearance and labeling is correct.

Thermal

Mechanical design, modeling and analysis are accomplished using Cadkey (read and import), Solidworks, Autocad, Flomerics FLOTHERM and Mathcad. Mechanical models, from the individual component to the overall system, are created in Cadkey and Solidworks. Flomerics FLOTHERM and Mathcad are used for thermal and structural analysis. Prototypes are also fabricated in Tracewell’s sheet metal facility for design verification and testing.

Reliability

The Tracewell engineering staff routinely performs design MTBF calculations using either MIL-HDBK-217 or Telcordia (Bellcore) SR-332 guidelines. Where appropriate, commercial data is used in the calculation. In agreement with customers, samples of production units are subjected to ongoing reliability tests (ORT) to detect any latent defects in an accelerated temperature burn-in. Where selected products have been traceable, field MTBF numbers have been achieved well in excess of 1,000,000 hours.

Data Collection

Several reporting mechanisms have been developed throughout our organization to collect, store, evaluate and disseminate data information from the design phase through end-of-life manufacturing. Process databases collect data from throughout the manufacturing process including board assembly test, unit first test, burn-in or ESS, unit final test, final inspection and pack. Repair loops collect data for all repairs at the board assembly and unit level. Our return goods area collects data on all repairs on returned product. These databases provide the ability to query for selected data criteria, as well as establish Pareto analysis and Cpk studies for process improvement.

A conscious effort is made to improve data collection. Current efforts include upgrading our returned goods database, expanding data collection to other inspection points and incoming component transformer parameters.

Testing

• Design Verification Testing (DVT)
• HALT
• High volume Burn-in/HASS (Production Test)
• EMC testing
• Visual test
• Configuration verification
• PCB continuity/resistance cable tests and crimp verification
• Software control burin-in bays
• Test Engineering
• Automated, scripted, custom, safety (leakage and Hipot)
• Safety approvals
• Thermal test
• System stress
• Shock and vibe
• Complex tech analysis