QML - The Best of Both Worlds | QML Joins Best of Military and Commercial Worlds | Screening
Quality In | QML Means Best Commercial Practices | QML
Manufacturing and Assembly | Customer Benefits
Under QML | QML Retains Best of Military World | DoD
and IC Industry Accept QML | TI & QML | QML Q & A
QML - The Best of Both Worlds
Visible evidence of a world defense in transition is all
around us. In recent years, changes once thought unlikely
became reality. Borders fell, political systems were restructured,
and alliances once considered impossible are now the norm.
While the major news events garnered most of the world's
attention, it may be the less publicized changes that define
the defense industry in the next century.
In the United States, defense acquisition reform is one
topic that received a great deal of attention in the last
several years. All of the speculation resulted in action
in 1994 when Secretary of Defense, Dr. William Perry, authored
a mandate that, in effect, called for the Department of Defense
to utilize performance standards to purchase components for
use in end systems. To ensure the mandate is adhered to,
any contractor involved in a new design or system upgrade
must obtain a waiver to use MIL-Spec product in a system.
This is a complete reversal to the policy in existence prior
to the Perry mandate.
The mandate was a decisive action aimed at moving the defense
procurement process away from the strict, regimented "mil-spec" system
that, in many cases, added unnecessary costs to defense contracts.
At the same time, the DoD sought to implement "Best Commercial
Practices" and to utilize many of the advantages found in
the commercial world.
One potential limitation of the DoD action was its broad-brush
approach covering everything purchased by the DoD and its
contractors, from boots to integrated circuits. For commodity
items like clothing, it isn't difficult to see the logic
in a less rigid, less costly commercial equivalent. However,
highly complex integrated circuits are a different matter.
Although the military semiconductor industry did not foresee
the DoD's action, its members recognized early the need for
changes in military ICs manufacturing and procurement. More
importantly, they recognized that their customers' needs
were changing. As a result, key industry members began working
proactively in the mid-1980s to develop a methodology that
preserved the high-quality, high-reliability ICs the armed
services had come to expect while also incorporating the
most advanced commercial qualification and procurement methods.
The result was a comprehensive process methodology named
the Qualified Manufacturers List (QML).
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QML Joins Best of Military and Commercial Worlds
The DoD originally listed the Qualified Manufacturers List
as an ordinary military standard. It was a mil spec for classification
purposes, but for practical purposes it was anything but
a mil spec. The government formally recognized this in early
1995 and gave QML the status of MIL-PRF-38535. This means
that QML officially went beyond mil-spec status to meet the
definition of a "performance- based specification" as called
for in Dr. Perry's earlier mandate. For both IC manufacturers
and defense contractors, the decision went a long way in
providing an IC standard that offers the best of both the
military and commercial worlds.
The benefits of QML are many, but they are best understood
when comprehended against the system QML replaced.
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Screening Quality In
From the inception of the IC by Texas Instruments Jack Kilby
in 1958, quality and reliability remain primary manufacturing
objectives. TI designed the first integrated circuits for
use in military systems, and these ICs had to perform to
the rigid standards prescribed by the US government. As a
result, a testing and reliability environment grew up around
the industry ensuring the parts designated for military use
would perform to expectations in a wide range of extreme
The result of this early work was a broad system named the
Qualified Parts List (QPL) system. Administered under the
armed services supply center, DESC, QPL's charter was to
guarantee the ICs purchased by military contractors met the
U.S. Government's strict standards.
The process evolving under the QPL system became known as
JAN and is described under the DSCC standard MIL-M-38510
and additionally under MIL-STD-883, Paragraph 1.2.1 in which
the Joint Army-Navy (JAN) look-alike parts were built. The
main benefit of MIL-M-38510 in the early days, and ironically,
its biggest drawback today, is the fact it attempts to "screen" quality
in through a rigid set of tests that manufactures complete
for each and every device lot.
Regardless of device type or maturity, the manufacturers
perform the same tests for every lot in spite of manufacturers'
data showing parts of the qualification process might be
dropped without affecting the device's reliability.
While the QPL system remained inflexible for decades, the
semiconductor industry did not. The industry continued to
improve quality and reliability through process manufacturing
techniques like Statistical Process Control (SPC). Instead
of trying to screen out defective products after they have
been manufactured, QML ensures quality and reliability in
the manufacturing process.
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QML Means Best Commercial Practices
For early IC manufacturing, the QPL system worked well,
but it did not incorporate the many advances in process technology
the IC industry achieved over the years. QML, on the other
hand, was designed to incorporate these best commercial practices
into its comprehensive methodology. The fundamental difference
between the two systems is that QPL is a strictly prescribed
guideline for achieving quality. In contrast, the QML process
is flexible and allows the manufacturer to do the thing he
does best -- continuously improve the process for manufacturing
a quality product.
For the manufacturer, and ultimately the consumer, the most
important benefit of QML is it allows the elimination of
non-value-added steps. The older QPL specification mandated
each and every device coming off of an IC assembly line must
be subjected to the same rigorous quality checks, despite
years of data indicating parts of the screening process were
unnecessary. The QML process allows the advantage of analyzing
data gathered from the manufacturing and testing process.
When the manufacturer has sufficient data to prove a particular
step is no longer necessary, he can delete it.
Centrifuge, 100X inspection, temperature cycle and burn-in
are examples of eliminated process steps on TI's older technology
devices made possible through QML. As manufacturers accumulate
additional data, more flow deletions are possible.
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QML Manufacturing and Assembly
Another advantage of QML is it qualifies the entire product
family via certification of the process flow. Once an IC
company's process has been certified or listed as QML, the
manufacturer must continually meet or improve on the established
baseline under which it qualified.
The DoD has announced the approval of self-certified, off-shore
wafer fabs under MIL-PRF-38535. Under the QPL system, all
wafer fabs sourcing QPL ICs were required to be located in
the United States. This effectively limited the number and
types of devices available to military customers. With QML,
customers have more total system solutions from which to
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Customer Benefits Under QML
From a production perspective, QML customer benefits include
the manufacturer's ability to convert rapidly to new technologies.
Reduced screening means reduced cycle times, and since QML
allows elimination of non-value-added manufacturing steps,
QML has the potential for cost containment. In addition to
rapid product introduction, reduced cycle time and potential
cost savings, QML devices do not suffer from the defects
sometimes induced by an extensive screening process. Rigorous
screening does not improve the quality of the part. In some
cases, it may even hinder device quality.
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QML Retains Best of Military World
While QML incorporates many of the benefits found in the
commercial IC manufacture, qualification and procurement
world, it also retains the best features traditionally found
in the military IC world. Retained are the types of special
services military customers have come to expect as vital
to the specialized design and procurement environment in
which they work. Configuration control, device traceability,
standardized supplier certification and obsolescence control
are just some QPL attributes maintained under QML.
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DoD and IC Industry Accept QML
Early on, DSCC recognized that QML provided not only a screen
for quality products but one for quality organizations as
well. As a result, DSCC considers QML product equal to or
better than QPL products. Jim Blanton of DSCC explains. "The
QML approach is basically a validation that a company is
well managed and technically sound enough to be "World Class" with
minimum government interference."
Long-term suppliers in the IC industry accept QML as the
methodology of choice. To date, there are currently 27 QML
suppliers in the industry. The significance for customers
is the assurance of a long-term and multiple-source supply
for their military systems.
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TI and QML
QML was given life through the government's support of TQM
(Total Quality Management) programs in the 1980's. TQM, initially
designed for application to any manufacturing system, is
especially ideal for the precision techniques found in IC
manufacturing. Texas Instruments has long been a supporter
of TQM principles and recognized early on the need for performance-based
specifications for military IC manufacturing. As a result,
TI was a pioneer in the development of the QML performance-based
Today, Texas Instruments HiRel Defense & Aerospace is the
largest supplier of QML products with over 3,500 device types.
And as part of its ongoing pledge to serve its military and
aerospace customers, TI continues to release new standard
and differentiated products qualified to QML specifications.
From new advanced system logic and mixed-signal functions
to highly integrated DSP multichip modules, TI provides the
tools you need to compete in today's changing military market.
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QML Q & A
- What does QML mean?
Qualified Manufacturers List
- Is QML a military specification?
No. QML is a performance base specification, MIL-PRF-38535.
- Where do DSCC SMDs, JAN and SNJs fit under the QML
The SMD, JAN and SNJ specifications now define the electrical
performance specification for the particular device. These
devices may now be built using the QML (MIL-PRF-38535)
as the process performance specification.
- What is Best Commercial Practices and how does that
relate to QML?
Best Commercial Practices is a term applicable to any business
product, process or system. It implies the elimination
of non-value added steps.
QML allows a supplier with significant statistical data,
to eliminate process steps which do not add value to a
- How can I tell if the processing of a device has changed
All TI Military devices, with the exception of mil-temp
(SN/SM) and plastic, are shipped with a Process Conformance
Report that shows what processing the devices received.
- How does TI decide what process steps should get eliminated
from a device flow?
TI first collects significant statistical data proving
a given process step is not adding value to a device flow.
With the agreement of the Technology Review Board (TRB),
the process step can then be eliminated. ex. 216,670 HC/HCT
devices were tested at -55 with zero test related failures.
-55 is no longer performed on HC/HCT devices.
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