(Milpitas, CA) - Continuous Improvement. When there's a great deal of low-hanging
fruit to gather, it's an easy concept to embrace. But what happens
when all the easy stuff is done and expectations for continuous improvement
still exist? Such has been the challenge for Senior Facility Manager,
Dan Burris, and his team at the Silicon Valley headquarters of Headway
Technologies, a TDK subsidiary.
Headway Technologies, a subsidiary
of TDK Corporation,
is located in Silicon Valley.
Headway manufactures, in clean room fashion, aluminum titanium carbide
wafers consisting of thousands of read/write heads used in computer
hard drives. TDK sales of such devices account for about 1/3 of
all such sales worldwide. The exacting standards for such fabrication
necessitates that Class 100 clean rooms dominate the 115,000 sq. ft.
Their ISO-14001 registered quality system instills an inherent amount
of interest in continuous improvement. Accordingly, each year
Headway and TDK management determine high-level goals and more specific
objectives, including those related to energy-use reduction. Such
goals are always based on the fabrication capacity requirements.
Beyond this driver, the fact that the Headway fabrication facility
is located in Silicon Valley puts inherent pressure on management to
contain costs so that they can remain competitive in the worldwide manufacturing
“For the last 5 years,” Dan Burris explains, “we've had a year-over-year
decrease in energy use as we planned. But we had done so through
all the low-hanging fruit such as lighting and high-efficiency motors
on the HVAC equipment.”
“When we reached the extent of our internal knowledge,” he continues,
“we had to look to external sources for skill sets we did not have
internally. Specifically, we needed to evaluate our entire mechanical
systems and to optimize their performance.”
That search eventually led Dan and his team to Comfort International
Inc., an authorized representative of KMC Controls. Alan Pong
is President of Comfort International.
“Dan certainly put the fear of God in us as he explained the demands
of the project,” Alan says. “We needed to achieve a 10% reduction
in energy usage and do so without disrupting the fabrication process.
'Thou shalt not hurt the fab,' is Dan's cardinal rule,” Alan concluded
with a smile.
He is referencing here several characteristics peculiar to the project.
First, Headway is a 24/7/365 operation. Second, each of their
many clean rooms contains dozens of tools or production machines churning
out the wafers through 1000 distinct fabrication steps and cycle times from 8 to 12 weeks per
product. Third, these tools depend on the building's mechanical
systems for their operation. Fourth, this fabrication requires
unyielding standards for temperature and humidity control. The
environment must be maintained at 68° F +/- 1° and 45% relative humidity
Any deviation from these standards can cause a shutdown and affect
multiple layers of the wafer and millions of dollars in losses.
Just 30 minutes of out-of-spec humidity can erase 4 to 5 hours of production
(and it grows exponentially from there).
Alan's first task in preparing for the project was to conduct a deep
energy audit. “A base audit had been completed by a previous
contractor,” Alan explains. “But we had to go deep to full
ASHRAE standards, and do so over a period of two months, in order to
put together the required profiles and go back to Dan with our proposal.”
That proposal, in essence a performance contract, called for a savings
of 4.8 million kilowatt hours of electricity per year and 324,000 therms
of gas per year with a 1.5 year payback.
It would not be easily accomplished.
Dan Burris explains: “Our incremental growth over the last 20 years
had led to a bunch of equipment that's not in harmony or efficient as
a whole. We had dissimilar pipe pressures and pipe diameters.
We had four different mechanical yards, each with chillers and towers.
We needed a way to look at this intelligently and make comprehensive
decisions versus discrete ones.”
That sort of system-level thinking was exactly what Alan Pong and
his team at Comfort International brought to the table.
“We modified the design and operations of the facility by creating
an entirely new way to utilize the existing primary equipment,” Alan
“Alan did take a different approach,” Dan Burris adds. “While
we had vetted another contractor for this project, their proposal was
lacking in that they really didn't understand our constraints or take
a comprehensive approach that we wanted. By the time we pulled
out from their proposal all that wouldn't work for us, the ROI became
“Alan, on the other hand,” Dan continues, “illustrated a complete
understanding of our facility and our needs through his energy audit
and resulting profiles. He then applied a creative control approach.”
The project revolved around the facility's air handling units.
There are 20 standard and 52 re-circulating AHUs on site used for both
supply air and re-circulating air purposes.
“In particular,” Alan says, “the re-circulating AHUs were oversized
and had crude dampers. We needed better control to achieve the
To lay the foundation for this control, Alan's team added Toshiba
variable frequency drives of varying capacities (30, 20, 15, 10 &
7.5 horsepower). Comfort International also replaced 22 damper
assemblies with highly controllable ones. VFDs were also added
to other rooftop units and water pumps.
With this foundation in place, Comfort International added numerous
and precision sensors to the clean rooms and outfitted each AHU/VFD
pair with model A1616 BTL-listed BACnet building controllers from KMC
Controls. The high resolution of A-to-D conversion on the inputs
of the controllers was needed to properly manage the highly accurate
Beyond equipment, real energy savings were realized with a change
to the control logic.
Says Dan Burris: “We had been conditioning 100% of the air, supply
air and re-circulated air. A given clean room here uses the AHUs
to make 10 air changes per hour at 90 ft/min. Outside air must
be heavily conditioned before it reaches the HEPA filters and flow modules.”
“Alan's idea was to only condition the initial supply air and any
make-up air,” Dan continues. “If we consider the total
or 100% of supply air in circulation at any given time, we realize that
some is lost through the production tool exhaust and some through the
occasional open door to the clean rooms. In reality, of 100% to
start, only 70% makes it back for recirculation.”
“Alan's stroke of brilliance was that 70% of the air was already
conditioned. It may have acquired only some latent heat load along
the way. It could be brought back into spec with only minimal
intervention. So the focus then shifted to the 30% make-up air.”
At TDK headquarters, Dan Burris (center)
holds the recognition reward check form PG&E.
Alan Pong (second from right) is assisting.
Beyond these air-related measures, the facility and contractor team
had to look at water usage and its conditioning. The facility
uses chilled water, hot water, and steam for domestic and production
purposes. Here VFDs were also added to appropriate motors and
valve changes were introduced for greater controllability.
“For the chillers,” Alan says, “we raised the water temperature
to optimize the strategy for the best combination for the supply cooling
load. We also staged the chillers to maintain proper flow to the
“For boilers,” Alan continues, “we saw that they had been set
to maintain a constant PSI. Through new sensors and controllers,
we changed this strategy to achieve the target PSI only when needed.
But we always had enough capacity in standby mode to accommodate production
What results have been achieved as a result of these measures?
“ROI occurred in 10 months,” says Dan Burris enthusiastically.
“On the electrical side, we went from a continuous demand of 5.4 megawatts
to 4.7 megawatts. In fact, we've seen it as low as 4.4 megawatts.
That's enough to power 128 homes per year and easily surpasses our 10%
reduction goal. It also represents a direct costs savings of over
With regards to gas, Dan's team was disappointed to learn that a key
gas meter had failed, giving them good data only after it had been replaced,
which was after project completion. Comparative data from before
the project is not available. “However,” Dan states, “I
can say that we went from a total of ten operating boilers for hot water
and steam production to only five in operation today. That's a
50% reduction in these big users of gas.”
As a direct result of these energy savings, Headway Technologies/TDK
was recently rewarded by Pacific Gas & Electric with a handsome
rebate check for over $633,500. This award was presented in a
special ceremony at Headway headquarters in Milpitas on March 24, 2013.
It was noted as being the largest of such rebates given within Silicon
At the same award ceremony, the mayor of Milpitas, Jose Esteves, presented
a certificate to the Headway staff recognizing their contributions to
global CO2 reductions.
Mayor Jose Esteves (center in suit)
presents a CO2 reduction recognition certificate
to Dan Burris.
The efforts of the Headway Technologies facility staff have not gone
unnoticed within the TDK family. Representatives of Headway's
sister plant in Japan (also responsible for the same product line) are
planning a visit to Silicon Valley to see if some of the lessons learned
and results achieved could be applied there.
Such are the possibilities when vision and planning for continuous
improvement meet technical creativity and competence.