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Today’s
electronics manufacturers face unprecedented cost and
time-to-market pressures. As the complexity of electronics systems
has rapidly increased and component costs and margins have
continued to shrink, testing has become a larger contributor to
the final cost of manufactured goods. To remain competitive,
contract manufacturers and OEMs are looking for ways to lower the
cost of test by increasing test throughput, increasing their
development productivity, and reducing maintenance and support
costs.
Lowering
the cost of test
The economic impact of a
test system is typically measured in the cost as amortized over
all of the products tested. The cost of test is an important
metric because it measures capital expenditure with respect to the
test throughput and productivity that a system achieves. Therefore
lowering the cost of test, an important goal of manufacturers, can
provide a significant competitive advantage.
We
propose a functional test platform that lowers the cost of test in
three key ways:
Strategy
1 — Increasing test system throughput
Increasing throughput is
a goal of every high-volume manufacturer. In many manufacturing
lines, functional test cannot keep up with the beat rate of
devices coming out of production. Because it is usually highly
undesirable to slow down the production process to accommodate
test, the most common solution is to have multiple functional
testers at the end of each line to keep up with the production
throughput. This condition is commonly called test fan-out.
Because this proliferation of test equipment can be avoided by
reduced test times, lower capital equipment expenditures can be
achieved.
The
PXI platform provides tremendous performance advantages over other
hardware platforms. Built on the industry-standard PCI bus, PXI
offers data throughput of up to 132Mbytes/s — more than 100
times faster than the throughput of a GPIB device. This high data
throughput means you can quickly transfer measurement data from
the measurement device to the computer where you can make a
decision or log the data, and thus significantly reduce the test
time for the device.
To
further increase throughput, PXI provides star-triggering
capability. With the star trigger, several PXI devices can be
tightly synchronized on common trigger or clock signals. In many
applications, the use of the star trigger has resulted in
throughput gains of 10X or more.
To
deal with fan-out at functional test, many manufacturers place
several independent, identical testers in parallel. However, this
method uses capital equipment very inefficiently, because even
under-used instruments are duplicated for each tester. A far more
efficient method is to test several devices in parallel on a
single, parallel tester with multiple test sockets. A parallel
test strategy offers the most efficient use of equipment because
more expensive, under-used instruments can be shared among sockets
while more common instrumentation can be duplicated per socket for
maximum throughput.
Strategy
2 — Increasing engineering productivity
Decreasing time to
market continues to pressure today’s manufacturers. In consumer
electronics and communications sectors, product life cycles have
shrunk from 18 months to six months or less. Getting a product
into volume production and on the market as soon as possible can
make the difference between a successful product and a failure. In
highly competitive industries, for example, a 6-month delay in the
shipment of a product can result in more than a 30% decrease in
cumulative profits over the entire life cycle of the product. For
such applications, developing a manufacturing test system rapidly
is essential, as is quickly adapting a tester after product
revisions.
Technologies
based on widely available commercial technologies have inherent
productivity advantages. PXI, for example, takes advantage of
standard Intel and Microsoft platforms to deliver plug-and-play
device installation and easy, consistent device configuration. PXI
measurement devices also offer increased flexibility over
proprietary platforms, because the PXI device makes only the raw
measurement and uses software for analysis and decision making.
Thus, when new products are brought to production, systems using
PXI can be quickly changed to add new measurement routines in
software, often without requiring hardware changes.
To
maximize productivity in test development, development
environments designed specifically for test applications include
the correct tools for measurement and analysis.
Another
way to maximize productivity is to use commercially available
software whenever possible instead of creating custom software
packages in house. Many organizations, for example, write their
own test executives instead of using an off-the-shelf product.
Spending valuable engineering time recreating software that
already exists reduces overall productivity and ties up even more
resources over time for maintenance of the software. Today’s
successful manufacturing organizations concentrate on core
competencies such as the design of products and test strategies to
achieve the most efficient use of available resources.
Strategy
3 — Lowering overall cost of ownership
The cost of the test
system is measured in two quantities:
•Initial
cost of the equipment, plus development and/or integration
services.
•Cost
over time for maintenance and support of the test system.
The
NI test platform can substantially lower both of these costs.
PXI
measurement devices use commercially available technologies such
as standard integrated circuits for analog-to-digital conversion
and PCI bus interfacing. Because these devices are widely used in
other high-volume technologies, such as telecommunications and
consumer electronics products, their unit cost is substantially
lower than highly customized components. This feature results in
measurement functionality at cost much lower than devices in
proprietary platforms. In addition, the PXI platform uses
components already present in your computer — the processor,
memory, and monitor — to perform the measurement analysis and
display instead of duplicating this functionality in a customized
box instrument.
PXI
also lowers costs by delivering a platform capable of diverse
measurement and control capability. In many systems, the platform
for analog measurements is completely separate from functionality
such as optical inspection, motion control, or continuous data
acquisition. PXI, however, integrates this diverse set of
measurements into a single hardware platform to lower your overall
equipment costs and to permit a greater degree of integration
between these systems.
Much
of the total cost of a test system comes after the initial capital
expenditure, because software training and maintenance costs can
add significantly to the cost of test. Commercial software
significantly reduces your maintenance and support costs. Widely
used commercial software has standard training, technical support,
and a large user base. The more commercial technologies you can
use in your test system, the better you can take advantage of
these cost savings. Maintenance is often a hidden cost in software
development. All software requires some amount of maintenance over
time. Keeping up with the latest operating systems, for example,
is a requirement for compatibility with hardware and other systems
in the enterprise. Porting customized software to a new operating
system can use up valuable resources and time. Some companies have
spent several million dollars, for example, to port in-house test
software from DOS to Windows NT. Using commercial software tools
offloads much of the maintenance burden to the software vendor and
lowers your overall cost.
Results
Building
a functional test system on widely used hardware and software
platforms built on commercial technologies and open industry
standards will dramatically lower your cost of test. This platform
will increase your test throughput with fast measurement hardware
and software capable of managing multiple test routines in
parallel. Engineering productivity will increase, because
engineers can fully take advantage of powerful software programs
to develop tests rapidly. The time required to redesign test
systems for new products will decrease with the use of flexible,
modular software and hardware platforms. Finally, the cost of the
test system, both in initial capital expenditure, and in overall
cost of ownership, will be drastically lower thanks to the
leverage of commercial technologies and widely used standards.
For
more information visit www.ni.com or email arturo.quezada@ni.com
or eloisa.acha@ni.com.
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