
The Fleck Materials Seminar, held in conjunction with FCC '99,
was held on the afternoon of September 30 with the following speakers
participating: 1999 FMS Speakers This year’s distinguished group of industry executives was composed
of the following speakers, listed in order of presentation:
- Fleck Research
Industry Statistics and Trends for Polymer Resins,
Copper-based Alloys and Contact Plating
- I-Yuan Wei, principal consultant, Apex Electrical Interconnection
Consultants
Thin Gold Technology for Electronic Contact Applications
- Abid A. Khan, director of market development, Olin Brass
Copper Alloy Usage in the Electronic and Automotive
Connector Markets: A Global Overview
- Ajit C. Munshi, senior consultant, plastics, Apex Electrical
Interconnection Consultants
Current & Future Trends of Polymers Used in E/E
Products
- Spencer H. Siegel, electrical/electronics market development
manager, Phillips Chemical Company
New PPS Alloys for Thin-Walled SMT Connector Designs
- Robert A. Michelson, principal consultant, Apex Electrical Interconnection
Consultants
Metallurgical Concerns With Next Generation Connectors
- Bipin Doshi, principal consultant, Apex Electrical Interconnection
Consultants
Current and Future Trends in Organic Coatings and
Lubricants for Contacts
Copper-based Alloys Examined
Fleck Research opened the seminar with a report on copper-based
alloys for contacts, noting that nearly 400 billion contacts were
produced within U.S. non-captive factories in North America last
year. Of these, almost 170 billion were utilized in printed circuit
connectors, while another 124 million went to automotive connectors.
Electronic connectors made up the bulk of copper-based alloy use
during 1998 with 220 million pounds, Fleck reported, while the industry
in general used 316 million pounds from non-captive manufacturers.
Captive manufacturers contributed another 103 million pounds of
copper-based alloys.
Polymer resins for insulators accounted for 10 billion insulators
in North America last year, with non-captive manufacturers accounting
for nearly eight billion of these. Fleck reported that North America
utilized 175.7 million pounds of polymer in 1998.
Worldwide, the connector industry utilized 412.5 million pounds
of polymer, with PBT accounting for nearly half of the total at
193.6 million pounds and nylon 66 taking 26.3% with 108.3 million
pounds.
Thin Gold Technology for Electronics
Apex’s I-Yuan Wei, recently retired from AMP after 17 years as
director of contact materials, has contributed significantly to
thin gold technology, palladium and palladium alloy plating, non-corrosive
coating, hydrogen embrittlement, pulse plating alternative to tin-lead,
graphite composite coating and high-temperature coating.
Speaking on thin gold technology for electronic contact applications,
Wei noted that this contact interface is fundamental to connectors.
Separable interfaces involve geometry, normal force and finish/morphology,
while permanent interfaces are concerned with mechanical (crimp,
press in, insulation displacement) and metallurgical (soldering
and welding).
Reasons for using gold contacts, he explained, include metal-to-metal
contact, which offers corrosion protection, free oxide film and
no fretting. Electrical and thermal properties also are factors.
Thin gold technology possesses cost vs. performance advantages
of porosity, wearability and thermal stability, Wei pointed out.
“There is,” he added, “no good replacement for gold.” Potential
contact finishes include composite gold, composition modulated alloy,
laser-enhanced plating, solder jet deposition, vacuum deposition,
pyrolysis, inlay and conductive polymer.
Copper Alloys in Electronics and Automotive Markets
Abid Khan has spent the past quarter-century at Olin Brass, starting
as a research engineer before switching to technical marketing.
As director of market development, he is responsible for the company’s
high-performance alloy business worldwide, focusing primarily on
the electronic and automotive end-use markets.
“The name of the game in the electronic connector market is smaller,
faster, cheaper and reliable,” Khan stated. “The challenge for the
designers is how to continue to miniaturize, maintain a rugged construction
using less material, maintain signal integrity at ever-increasing
speeds and accommodate automated assembly.”
As the density increases, he noted, the designers are going from
conventional pin and socket design to area array interconnects—similar
to what is used in semiconductor packaging—or blade and beam-type
contacts. Khan pointed out that the global workhorse in the electronic
connector segment are the phosphor bronze alloys. Brass is used
where it provides acceptable performance and beryllium copper is
used only if one needs the unique properties it offers because of
the significant cost penalty, he added.
“More recently, our customers have demanded a cost-effective alternative
to phosphor bronzes,” Khan said. “Olin successfully introduced C663
as a phosphor bronze replacement alloy in 1997. It offers higher
conductivity, similar strength/bend and stress relaxation performance.”
Khan noted that his company is a major supplier to the U.S. automotive
market, which includes Japanese transplants. Olin’s position as
a major supplier in the automotive segment is leveraged by choice
of alloys, tin coatings and service capability, he said.
Concluding, Khan stated that in both the electronic and automotive
connector segments, material suppliers will continue to be challenged
by miniaturization, speed and power requirements, reliability and,
in automotive applications, the environment. In addition, global
availability issues and cost pressures will continue unabated.
Current & Future Polymer Trends
Ajit Munshi, a senior consultant with Apex with 30 years of experience
in plastics and rubber in electronic connector manufacturing, has
provided technical and consulting support in plastic materials selection,
failure analysis and fabrication techniques resulting in significant
cost savings for manufacturing of plastic housings.
He identified the high-performance polymer of the future as “syndiotactic
styrene polymer,” produced by Dow Questra-Crystaline Polymers. This
product supports high-temperature connector applications and high
performance resin for electrical engineering products.
Among the competitive advantages of the Questra series are high
heat resistance, simple processing and lower comparative cost, Munshi
noted. He also cited stability, low dielectric constant, high insulation
resistance and good tracking resistance.
Typical applications for this product, he reported, are telecommunication
connectors, automotive “under the hood” electrical connectors, PCB
connectors, I/O connectors and integrated circuit connectors.
“The industry is demanding higher performance with lower cost,”
Munshi stated. “Polymer suppliers are developing new materials,
and designers must understand performance requirements for optimum
cost/performance.”
Polyphenylene Sulfide Alloys for Connector Designs
Spencer Siegel of Phillips Chemical, who has marketed high-temperature
materials for the connector/socket market for the past 10 years,
was instrumental in obtaining material specification for Ryton PPS
in Slot 1, Seagate’s 2mm bottom entry connector, various high speed
and high density connectors and sockets. He introduced a new line
of polyphenylene sulfide alloys under the trade name Xtel.
Trends in the connector industry, Siegel noted, are toward surface
mount technology, miniaturization and higher pin densities. Plastic
material, he said, results in improved electrical, mechanical and
thermal performance, as well as improved mold-filling capability
and flash resistance, along with cost reduction.
“Utilization of Ryton,” he stressed, “results in thermal and dimensional
stability, mechanical integrity and improved electrical performance.
Xtel PPS alloys expand the capabilities of PPS to meet the demands
of the connector/socket marketplace.”
Siegel pointed out the advantages of Xtel alloys, which included
SMT compatibility, flash-free parts, high weldline strength, low
mold temperatures and fact cycle times.
Future Trends for Metals in Connectors
Robert Michelson, a 33-year veteran of the plating and metals field,
spent 24 years at AMP in the technology division, where he worked
on metallizing plastic films and the problems associated with gold
reduction. He was credited with company savings of over $30 million
a year for his gold reduction efforts.
Regarding metal selection in the connector industry, Michelson
noted that “I expect change to be very slow and gradual.” He predicted
that the backbone of the metals business will remain phosphor bronze,
brass and a little beryllium copper.
“Costs of metals were driven down in the 1990s, but product performance
remained up,” he declared. “In the 2000s, cost will be driven way
down, but there will be relaxed performance.”
Historically, he noted, products in the telecommunications and
mainframe computer industry sustained a 40-year life. At present,
with constant technological advances, there is a 40-month life—if
that long—for desktop computers, cellular phones and consumer electronics.
Choosing the proper metal involves a consideration of the total
connector system, Michelson said, adding that “Properly designed
plastic parts can help avoid overstressing the metal and plating
can stiffen the spring characteristics.” He noted that RS-232 connectors
now are using brass where phosphor bronze was the alloy of choice.
Michelson reported that Alloy 7025 has eroded the high-end beryllium
copper market with its properties close to that metal, but at a
much lower cost. Alloy 171 is a beryllium copper alloy being developed
to counteract that trend, and it reportedly will be available at
a lower cost than historical BeCu alloys.
He cited Alloy 688 as an attempt to come up with a new alloy with
superior physical properties. “However, the tradeoff syndrome hit.
The alloy has poorer stress relaxation properties, higher than normal
die wear and the aluminum and cobalt oxides make plating more difficult.”
One way around the problem, Michelson said, is the use of mixed
metals, allowing greater versatility. What is required is a material
without magnetic properties.
“We will see attempts to dethrone brass and phosphor bronze allows,
but for many applications they are still the best,” he declared.
“Why go to a single source for an exotic alloy at a premium price
if it really doesn’t buy you much?”
Trends in Contact Lubricants
The final speaker was Bipin Doshi, who in his 30 years of industrial
experience has developed lubricant formulations for automotive,
metal working, aerospace and marine guidance systems. During his
20 years with AMP, he resolved corporate challenges of electrical
contact and stamping lubrication, surface treatment, sealant and
corrosion inhibiting coatings.
Doshi pointed out the reasons for applying a lubricant to electrical
contacts—reduction of mating forces, enhancement of plating durability
and corrosion protection, improving crimping and assembly tool life
and solderability shelf life. The same factors, basically apply
to the lubrication of contact materials.
“Value added” contact lubricants were recommended for the automotive,
telecom, computer, consumer products, outdoor products, consumer
electronics and power utilities industries. Doshi’s checklist for
contact lubricant selection included connector materials, electrical
loading, mechanical stress and operating environment.
Contact lubricants, he concluded, should offer good lubrication,
low volatility, good corrosion protection, oxidative stability and
compatibility with housing materials.
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