25-40W, SINGLE OUTPUT DC/DC CONVERTERS
Quality and Reliability
The UPB Models are the latest DC/DC Converters to emerge from DATEL’s
new, company-wide approach to designing and manufacturing the most
reliable power converters available. The five-pronged program draws our
Quality Assurance function into all aspects of new-product design, develop-
ment, characterization, qualification and manufacturing.
Design for Reliability
Design for Reliability is woven throughout our multi-phased, new-product-
development process. Design-for-reliability practices are fully documented
and begin early in the new-product development cycle with the following
1. To work from an approved components/vendors list ensuring the use of
reliable components and the rigorous qualification of new components.
2. To design with safety margins by adhering to a strict set of derating
guidelines and performing theoretical worst-case analyses.
3. To locate potential design weaknesses early in the product-development
cycle by using extensive HALT (Highly Accelerated Life Testing).
4. To prove that early design improvements are effective by employing a
thorough FRACA (Failure Reporting Analysis and Corrective Action) system.
The goal of the accelerated-stress techniques used by DATEL is to force
device maturity, in a short period of time, by exposing devices to excessive
levels of "every stimulus of potential value." We use HALT (Highly Acceler-
ated Life Testing) repeatedly during the design and early manufacturing
phases to detect potential electrical and mechanical design weaknesses
that could result in possible future field failures.
During HALT, prototype and pre-production DC/DC converters are subjected
to progressively higher stress levels induced by thermal cycling, rate of
temperature change, vibration, power cycling, product-specific stresses (such
as dc voltage variation) and combined environments. The stresses are not
meant to simulate field environments but to expose any weaknesses in a
product’s electro/mechanical design and/or assembly processes. The goal of
HALT is to make products fail so that device weaknesses can be analyzed
and strengthened as appropriate. Applied stresses are continually stepped
up until products eventually fail. After corrective actions and/or design
Typical HALT Profile
Test Time (minutes)
changes, stresses are stepped up again and the cycle is repeated until the
"fundamental limit of the technology" is determined.
DATEL has invested in a Qualmark OVS-1 HALT tester capable of applying
voltage and temperature extremes as well as 6-axis, linear and rotational,
random vibration. A typical HALT profile (shown above) consists of thermal
cycling (–55 to +125°C, 30°C/minute) and simultaneous, gradually
increasing, random longitudinal and rotational vibration up to 20G’s with load
cycling and applied-voltage extremes added as desired. Many devices in
DATEL’s new A-Series could not be made to fail prior to reaching either the
limits of the HALT chamber or some previously known physical limit of the
device. We also use the HALT chamber and its ability to rapidly cool devices
to verify their "cold-start" capabilities.
For each new product, electrical performance is verified via a comprehensive
characterization process and long-term reliability is confirmed via a rigorous
qualification procedure. The qual procedure includes such strenuous tests
as thermal shock and 500 hour life. Qual testing is summarized below.
High Temperature Storage
End Point Electrical Tests
DATEL in-house procedure
Max. rated temp., 1,000 hours
10 cycles, –55 to +125°C
+85°C, 85% humidity, 48 hours
DATEL in-house procedure
+70°C, 500 hours*
DATEL in-house procedure
Per product specification
* Interim electrical test at 200 hours.
In-Line Process Controls and Screening
A combination of statistical sampling and 100% inspection techniques keeps
our assembly line under constant control. Parameters such as solder-paste
thickness, component placement, cleanliness, etc. are statistically sampled,
charted and fine tuned as necessary. Visual inspections are performed by
trained operators after pick-and-place, soldering and cleaning operations.
Units are 100% electrically tested prior to potting. All devices are tempera-
ture cycled, burned-in, hi-pot tested and final-electrical tested prior to external
visual examination, packing and shipping.
Rapid Response to Problems
DATEL employs an outstanding corrective-action system to immediately
address any detected shortcomings in either products or processes.
Whenever our assembly, quality or engineering personnel spot a product/
process problem, or if a product is returned with a potential defect, we
immediately perform a detailed failure analysis and, if necessary, undertake
corrective actions. Over time, this system has helped refine our assembly
operation to yield one of the lowest product defect rates in the industry.
INNOVATION and EXCELLENCE
DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com Email: firstname.lastname@example.org
Data Sheet Fax Back: (508) 261-2857
DATEL (UK) LTD. Tadley, England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01
DATEL GmbH München, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025
DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein
do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.